@font-face {
  font-family: "Literata";
  src: url("fonts/Literata-Variable.ttf") format("truetype");
  font-weight: 300 800;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "Golos Text";
  src: url("fonts/GolosText-Variable.ttf") format("truetype");
  font-weight: 400 700;
  font-style: normal;
  font-display: swap;
}
@font-face {
  font-family: "JetBrains Mono";
  src: url("fonts/JetBrainsMono-Variable.ttf") format("truetype");
  font-weight: 400 700;
  font-style: normal;
  font-display: swap;
}

:root {
  --paper: #f0f1eb;
  --surface: #fafaf6;
  --surface-2: #e7e9e1;
  --ink: #101312;
  --muted: #5f665e;
  --rule: #c9cdc3;
  --rule-strong: #9da396;
  --red: #c22e24;
  --red-dark: #9e211a;
  --red-soft: #f2dcd8;
  --blue: #1b4a61;
  --blue-soft: #dbe7ec;
  --green: #2f5d46;
  --green-soft: #dfe9e2;
  --max: 1440px;
  --serif: "Literata", Georgia, "Times New Roman", serif;
  --sans: "Golos Text", "Segoe UI", Arial, sans-serif;
  --mono: "JetBrains Mono", Consolas, "Courier New", monospace;
}

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 24px;
}

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

body::before {
  content: "";
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: -1;
  background-image: radial-gradient(rgba(16, 19, 18, 0.055) 1px, transparent 1px);
  background-size: 22px 22px;
  opacity: 0.35;
}

::selection {
  background: var(--red);
  color: #fff;
}

a {
  color: var(--blue);
  text-underline-offset: 3px;
}

button,
input {
  font: inherit;
}

button {
  color: inherit;
}

img,
svg {
  display: block;
  max-width: 100%;
}

code {
  font-family: var(--mono);
  font-size: 0.9em;
}

.skip {
  position: absolute;
  left: 16px;
  top: -80px;
  z-index: 100;
  background: var(--ink);
  color: var(--paper);
  padding: 12px 16px;
  text-decoration: none;
  font-family: var(--mono);
  font-size: 12px;
  text-transform: uppercase;
  letter-spacing: 0.08em;
}
.skip:focus {
  top: 16px;
}

.is-hidden {
  display: none !important;
}

:focus-visible {
  outline: 2px solid var(--blue);
  outline-offset: 3px;
}

/* ---------------------------------------------------------------- top bar */

.topbar {
  max-width: var(--max);
  margin: 0 auto;
  padding: 20px 32px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  border-bottom: 1px solid var(--rule);
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  color: var(--ink);
  text-decoration: none;
}

.brand-mark {
  width: 38px;
  height: 38px;
  display: grid;
  place-items: center;
  background: var(--ink);
  color: var(--surface);
  font-family: var(--serif);
  font-size: 24px;
  line-height: 1;
  position: relative;
}

.brand-mark::after {
  content: "";
  position: absolute;
  right: 4px;
  top: 4px;
  width: 6px;
  height: 6px;
  background: var(--red);
}

.brand-text {
  display: flex;
  flex-direction: column;
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  line-height: 1.3;
}

.brand-text small {
  color: var(--muted);
  font-size: 9px;
  letter-spacing: 0.06em;
}

.topbar-meta {
  display: flex;
  gap: 24px;
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
}

/* ------------------------------------------------------------------- hero */

main {
  max-width: var(--max);
  margin: 0 auto;
  padding: 0 32px;
}

.hero {
  display: grid;
  grid-template-columns: minmax(0, 1.25fr) minmax(340px, 0.75fr);
  gap: clamp(32px, 6vw, 88px);
  align-items: center;
  padding: clamp(48px, 7vw, 96px) 0 clamp(40px, 5vw, 64px);
}

.eyebrow {
  margin: 0 0 12px;
  font-family: var(--mono);
  font-size: 10px;
  font-weight: 500;
  line-height: 1.4;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
}

.hero-copy h1 {
  margin: 0;
  font-family: var(--serif);
  font-size: clamp(44px, 6.3vw, 88px);
  font-weight: 600;
  line-height: 0.97;
  letter-spacing: -0.035em;
  text-wrap: balance;
}

.hero-year {
  margin: 22px 0 0;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--muted);
}

.hero-year strong {
  color: var(--ink);
  font-weight: 700;
}

.hero-year span {
  margin: 0 6px;
  color: var(--rule-strong);
}

.lead {
  max-width: 53ch;
  margin: 24px 0 0;
  font-size: clamp(16px, 1.25vw, 18px);
  line-height: 1.55;
  color: #333934;
  text-wrap: pretty;
}

.hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 28px;
}

.status-note {
  display: flex;
  gap: 12px;
  align-items: flex-start;
  max-width: 62ch;
  margin-top: 32px;
  padding: 14px 0 0 16px;
  border-left: 2px solid var(--red);
}

.status-dot {
  flex: 0 0 auto;
  width: 7px;
  height: 7px;
  margin-top: 7px;
  border-radius: 50%;
  background: var(--red);
  box-shadow: 0 0 0 4px var(--red-soft);
}

.status-note p {
  margin: 0;
  font-size: 13px;
  line-height: 1.5;
  color: var(--muted);
}

.status-note strong {
  color: var(--ink);
  font-weight: 600;
}

/* ------------------------------------------------------------- exam cover */

.cover {
  position: relative;
  display: flex;
  flex-direction: column;
  min-height: 440px;
  padding: 24px 26px 22px 46px;
  background-color: var(--surface);
  background-image: repeating-linear-gradient(
    to bottom,
    transparent 0 31px,
    rgba(16, 19, 18, 0.05) 31px 32px
  );
  border: 1px solid var(--rule-strong);
  box-shadow: 12px 12px 0 var(--surface-2);
}

.cover::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: 27px;
  width: 1px;
  background: rgba(194, 46, 36, 0.55);
}

.cover-top {
  display: flex;
  justify-content: space-between;
  gap: 12px;
  font-family: var(--mono);
  font-size: 9px;
  letter-spacing: 0.11em;
  text-transform: uppercase;
  color: var(--muted);
}

.cover-number {
  margin-top: 34px;
  font-family: var(--serif);
  font-size: clamp(96px, 11vw, 168px);
  font-weight: 600;
  line-height: 0.72;
  letter-spacing: -0.07em;
}

.cover-number span {
  display: block;
  margin-top: 18px;
  font-family: var(--mono);
  font-size: 9px;
  font-weight: 500;
  letter-spacing: 0.16em;
  line-height: 1.4;
  text-transform: uppercase;
  color: var(--muted);
}

.cover-stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 14px 20px;
  margin: 28px 0 0;
}

.cover-stats div {
  padding-top: 8px;
  border-top: 1px solid var(--rule);
}

.cover-stats dt {
  font-family: var(--mono);
  font-size: 8px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
}

.cover-stats dd {
  margin: 4px 0 0;
  font-family: var(--mono);
  font-size: 22px;
  font-weight: 500;
  line-height: 1;
  font-variant-numeric: tabular-nums;
}

.cover-stats dd small {
  font-size: 10px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--muted);
}

.cover-foot {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 18px;
  margin-top: auto;
  padding-top: 24px;
}

.barcode {
  width: 132px;
  height: 26px;
  background: repeating-linear-gradient(
    90deg,
    var(--ink) 0 1px,
    transparent 1px 3px,
    var(--ink) 3px 5px,
    transparent 5px 7px,
    var(--ink) 7px 8px,
    transparent 8px 11px
  );
  opacity: 0.72;
}

.cover-caption {
  font-family: var(--mono);
  font-size: 8px;
  letter-spacing: 0.11em;
  text-transform: uppercase;
  color: var(--muted);
  text-align: right;
}

.stamp {
  position: absolute;
  top: 124px;
  right: 16px;
  transform: rotate(-7deg);
  padding: 6px 10px 8px;
  border: 2px solid var(--red);
  color: var(--red);
  font-family: var(--mono);
  font-size: 9px;
  font-weight: 500;
  line-height: 1.25;
  letter-spacing: 0.12em;
  text-align: center;
  text-transform: uppercase;
  opacity: 0.9;
  mix-blend-mode: multiply;
}

.stamp span {
  display: block;
  font-family: var(--serif);
  font-size: 24px;
  font-weight: 600;
  letter-spacing: 0.02em;
  line-height: 1;
  margin-bottom: 2px;
}

.cover-footnote {
  margin: 12px 0 0;
  font-family: var(--mono);
  font-size: 8px;
  line-height: 1.4;
  letter-spacing: 0.02em;
  color: var(--muted);
}

/* -------------------------------------------------------------- index strip */

.index-strip {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  border-top: 1px solid var(--ink);
  border-bottom: 1px solid var(--ink);
}

.index-strip div {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 14px 18px;
  border-right: 1px solid var(--rule);
}

.index-strip div:last-child {
  border-right: 0;
}

.index-strip strong {
  font-family: var(--serif);
  font-size: 26px;
  font-weight: 600;
  line-height: 1;
}

.index-strip span {
  font-family: var(--mono);
  font-size: 8px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
}

/* ---------------------------------------------------------------- workspace */

.workspace {
  display: grid;
  grid-template-columns: 190px minmax(0, 1fr);
  gap: clamp(24px, 4vw, 56px);
  align-items: start;
  padding: 48px 0 0;
}

.rail {
  position: sticky;
  top: 20px;
  align-self: start;
}

.rail-title {
  margin: 0 0 14px;
  font-family: var(--mono);
  font-size: 9px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
}

.rail-nav {
  display: flex;
  flex-direction: column;
  border-top: 1px solid var(--rule);
}

.rail-nav a {
  display: grid;
  grid-template-columns: 24px 1fr;
  gap: 8px;
  padding: 10px 0;
  border-bottom: 1px solid var(--rule);
  color: var(--muted);
  text-decoration: none;
  font-size: 12px;
  line-height: 1.35;
  transition: color 160ms ease, padding-left 160ms ease;
}

.rail-nav a:hover,
.rail-nav a.is-active {
  color: var(--ink);
  padding-left: 5px;
}

.rail-nav a.is-active {
  border-bottom-color: var(--red);
}

.nav-num {
  font-family: var(--mono);
  font-size: 9px;
  color: var(--red);
  padding-top: 2px;
}

.rail-note {
  margin-top: 28px;
  padding-top: 16px;
  border-top: 1px solid var(--rule);
}

.rail-note p {
  margin: 0 0 10px;
  font-size: 11px;
  line-height: 1.5;
  color: var(--muted);
}

.rail-note a {
  font-family: var(--mono);
  font-size: 9px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  text-decoration: none;
  border-bottom: 1px solid var(--rule-strong);
}

.registry-body {
  min-width: 0;
  background: var(--surface);
  border: 1px solid var(--rule);
  padding: 0 30px 36px;
}

/* ----------------------------------------------------------------- toolbar */

.toolbar {
  position: sticky;
  top: 0;
  z-index: 10;
  margin: 0 -30px;
  padding: 18px 30px 14px;
  background: var(--surface);
  border-bottom: 1px solid var(--rule);
}

.search-label {
  display: block;
  font-family: var(--mono);
  font-size: 9px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 7px;
}

.search-row {
  position: relative;
  display: flex;
  align-items: center;
}

#search {
  width: 100%;
  border: 1px solid var(--rule-strong);
  background: var(--paper);
  color: var(--ink);
  padding: 11px 42px 11px 13px;
  font-size: 14px;
  border-radius: 0;
  -webkit-appearance: none;
  appearance: none;
}

#search::placeholder {
  color: #8a9087;
}

#search:focus {
  border-color: var(--ink);
  outline: 0;
  box-shadow: inset 0 0 0 1px var(--ink);
}

.search-clear {
  position: absolute;
  right: 34px;
  top: 50%;
  transform: translateY(-50%);
  border: 0;
  background: transparent;
  font-size: 20px;
  line-height: 1;
  padding: 4px 6px;
  cursor: pointer;
  color: var(--muted);
}

.search-clear:hover {
  color: var(--ink);
}

.search-hint {
  position: absolute;
  right: 12px;
  top: 50%;
  transform: translateY(-50%);
  font-family: var(--mono);
  font-size: 10px;
  color: var(--muted);
  border: 1px solid var(--rule);
  padding: 1px 5px;
  pointer-events: none;
}

.chips {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 10px;
}

.chip {
  border: 1px solid var(--rule-strong);
  background: transparent;
  padding: 5px 9px;
  font-family: var(--mono);
  font-size: 9px;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  cursor: pointer;
  transition: background 150ms ease, color 150ms ease, border-color 150ms ease;
}

.chip:hover {
  border-color: var(--ink);
}

.chip.is-active {
  background: var(--ink);
  border-color: var(--ink);
  color: var(--paper);
}

.result-count {
  margin: 10px 0 0;
  font-family: var(--mono);
  font-size: 9px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--muted);
}

/* ------------------------------------------------------------- sections */

.registry-section {
  padding: 42px 0 12px;
  scroll-margin-top: 176px;
}

.registry-section + .registry-section {
  border-top: 1px solid var(--rule);
  margin-top: 28px;
}

.section-head {
  display: grid;
  grid-template-columns: 54px minmax(0, 1fr);
  gap: 16px;
  padding-bottom: 18px;
  border-bottom: 2px solid var(--ink);
}

.section-num {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--red);
  padding-top: 5px;
}

.section-copy h2 {
  margin: 0;
  font-family: var(--serif);
  font-size: clamp(28px, 3.2vw, 42px);
  font-weight: 600;
  line-height: 1.04;
  letter-spacing: -0.025em;
  text-wrap: balance;
}

.section-lead {
  max-width: 72ch;
  margin: 10px 0 0;
  color: var(--muted);
  font-size: 14px;
  line-height: 1.5;
  text-wrap: pretty;
}

/* --------------------------------------------------------------- changes */

.changes {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
  gap: 28px;
  margin: 24px 0 4px;
  padding: 22px;
  background: var(--surface-2);
  border: 1px solid var(--rule);
}

.changes h3 {
  margin: 0 0 8px;
  font-family: var(--serif);
  font-size: 22px;
  font-weight: 600;
  line-height: 1.2;
}

.changes-copy p:last-child {
  margin: 0;
  font-size: 13px;
  line-height: 1.5;
  color: #3e453f;
}

.change-list {
  margin: 0;
  display: grid;
  align-content: start;
}

.change-list div {
  display: grid;
  grid-template-columns: 92px minmax(0, 1fr);
  gap: 12px;
  padding: 9px 0;
  border-top: 1px solid var(--rule);
}

.change-list dt {
  font-family: var(--mono);
  font-size: 9px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--red);
  padding-top: 2px;
}

.change-list dd {
  margin: 0;
  font-size: 13px;
  line-height: 1.4;
}

/* ----------------------------------------------------------------- dates */

.dates {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 1px;
  margin: 24px 0 8px;
  background: var(--rule);
  border: 1px solid var(--rule);
}

.dates div {
  display: flex;
  flex-direction: column;
  gap: 5px;
  padding: 16px;
  background: var(--surface);
}

.dates .date {
  font-family: var(--mono);
  font-size: 19px;
  font-weight: 500;
  line-height: 1;
  font-variant-numeric: tabular-nums;
}

.dates .date-label {
  font-family: var(--mono);
  font-size: 8px;
  line-height: 1.4;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--muted);
}

.dates-note {
  margin: 0 0 6px;
  font-size: 11px;
  color: var(--muted);
}

/* ------------------------------------------------------------ document row */

.doc-list {
  border-top: 1px solid var(--rule);
  margin-top: 8px;
}

.doc {
  display: grid;
  grid-template-columns: 104px minmax(0, 1fr) auto;
  gap: 20px;
  align-items: start;
  padding: 20px 0;
  border-bottom: 1px solid var(--rule);
  position: relative;
}

.doc::before {
  content: "";
  position: absolute;
  left: -30px;
  top: 20px;
  bottom: 20px;
  width: 2px;
  background: transparent;
  transition: background 160ms ease;
}

.doc[data-year="2027"]::before {
  background: var(--red);
  opacity: 0.35;
}

.doc[data-year="2026"]::before {
  background: var(--blue);
  opacity: 0.3;
}

.doc:hover::before {
  opacity: 1;
}

.doc-code {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 7px;
  padding-top: 2px;
}

.code {
  font-family: var(--mono);
  font-size: 10px;
  font-weight: 500;
  letter-spacing: 0.06em;
  line-height: 1.2;
  color: var(--ink);
  white-space: nowrap;
}

.badge {
  display: inline-block;
  padding: 2px 5px;
  border: 1px solid currentColor;
  font-family: var(--mono);
  font-size: 8px;
  line-height: 1.3;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  white-space: nowrap;
}

.badge-project {
  color: var(--red);
  background: var(--red-soft);
}

.badge-approved {
  color: var(--blue);
  background: var(--blue-soft);
}

.badge-current {
  color: var(--green);
  background: var(--green-soft);
}

.badge-archive {
  color: var(--muted);
  background: var(--surface-2);
}

.doc-body h3 {
  margin: 0;
  font-family: var(--serif);
  font-size: 20px;
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: -0.012em;
}

.doc-body p {
  max-width: 74ch;
  margin: 5px 0 0;
  font-size: 14px;
  line-height: 1.5;
  color: var(--muted);
  text-wrap: pretty;
}

.doc-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 6px 14px;
  margin-top: 9px;
  font-family: var(--mono);
  font-size: 9px;
  line-height: 1.4;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--muted);
}

.doc-meta .source,
.alt a {
  text-transform: none;
  letter-spacing: 0;
  font-size: 9px;
}

.source {
  color: var(--blue);
  text-decoration: none;
  border-bottom: 1px solid rgba(27, 74, 97, 0.28);
}

.source:hover {
  border-bottom-color: var(--blue);
}

.doc-note {
  margin: 7px 0 0;
  font-size: 12px;
  line-height: 1.45;
  color: var(--muted);
}

.alt {
  color: var(--muted);
}

.alt a {
  color: var(--blue);
  text-decoration: none;
  border-bottom: 1px solid rgba(27, 74, 97, 0.28);
}

.doc-actions {
  display: flex;
  gap: 6px;
  justify-content: flex-end;
  padding-top: 1px;
}

/* ------------------------------------------------------------------ buttons */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 32px;
  padding: 7px 11px;
  border: 1px solid var(--ink);
  background: transparent;
  color: var(--ink);
  font-family: var(--mono);
  font-size: 8px;
  font-weight: 500;
  line-height: 1.2;
  letter-spacing: 0.07em;
  text-transform: uppercase;
  text-decoration: none;
  cursor: pointer;
  transition: background 150ms ease, color 150ms ease, border-color 150ms ease;
}

.btn:hover {
  background: var(--ink);
  color: var(--paper);
}

.btn-primary {
  background: var(--red);
  border-color: var(--red);
  color: #fff;
}

.btn-primary:hover {
  background: var(--red-dark);
  border-color: var(--red-dark);
}

.btn-ghost {
  border-color: var(--rule-strong);
}

.btn-ghost:hover {
  border-color: var(--ink);
}

/* ---------------------------------------------------------------- archive */

.archive-wrap {
  margin-top: 18px;
  border: 1px solid var(--rule);
  overflow-x: auto;
}

.archive-table {
  width: 100%;
  border-collapse: collapse;
  min-width: 620px;
  font-size: 12px;
}

.archive-table th {
  padding: 9px 14px;
  border-bottom: 1px solid var(--ink);
  font-family: var(--mono);
  font-size: 8px;
  font-weight: 500;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  text-align: left;
  color: var(--muted);
  background: var(--surface);
}

.archive-table td {
  padding: 10px 14px;
  border-bottom: 1px solid var(--rule);
  vertical-align: middle;
}

.archive-table tr:last-child td {
  border-bottom: 0;
}

.archive-table tbody tr:hover {
  background: var(--surface-2);
}

.archive-year {
  font-family: var(--serif);
  font-size: 19px;
  font-weight: 600;
  width: 78px;
}

.archive-composition {
  color: var(--muted);
  font-family: var(--mono);
  font-size: 9px;
  letter-spacing: 0.03em;
}

.archive-size {
  width: 86px;
  font-family: var(--mono);
  font-size: 9px;
  color: var(--muted);
  white-space: nowrap;
}

.archive-actions {
  width: 210px;
  text-align: right;
  white-space: nowrap;
}

.text-link {
  font-family: var(--mono);
  font-size: 8px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  text-decoration: none;
  border-bottom: 1px solid var(--rule-strong);
  margin-right: 12px;
}

.archive-actions .source {
  font-family: var(--mono);
  font-size: 8px;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  border-bottom: 1px solid rgba(27, 74, 97, 0.28);
}

.archive-note {
  margin: 18px 0 0;
  padding: 12px 14px;
  background: var(--surface-2);
  border-left: 2px solid var(--rule-strong);
  font-size: 11px;
  line-height: 1.5;
  color: var(--muted);
}

.archive-note p {
  margin: 0;
}

.archive-note code {
  font-size: 10px;
  color: var(--ink);
}

/* ---------------------------------------------------------------- sources */

.sources-section {
  padding-bottom: 32px;
}

.sources-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1px;
  margin-top: 18px;
  background: var(--rule);
  border: 1px solid var(--rule);
}

.source-card {
  display: flex;
  flex-direction: column;
  gap: 5px;
  padding: 18px;
  background: var(--surface);
  color: var(--ink);
  text-decoration: none;
  transition: background 150ms ease;
}

.source-card:hover {
  background: var(--surface-2);
}

.source-name {
  font-family: var(--mono);
  font-size: 8px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--red);
}

.source-title {
  font-family: var(--serif);
  font-size: 18px;
  font-weight: 600;
  line-height: 1.2;
}

.source-url {
  font-family: var(--mono);
  font-size: 8px;
  line-height: 1.45;
  color: var(--muted);
  word-break: break-all;
}

/* ------------------------------------------------------------- empty state */

.empty-state {
  padding: 64px 0;
  text-align: left;
}

.empty-state h2 {
  margin: 0 0 10px;
  font-family: var(--serif);
  font-size: 34px;
  font-weight: 600;
  line-height: 1.1;
}

.empty-state p {
  max-width: 55ch;
  margin: 0 0 18px;
  color: var(--muted);
}

/* ------------------------------------------------------------------ footer */

footer {
  margin-top: 72px;
  background: var(--ink);
  color: var(--paper);
  border-top: 4px solid var(--red);
}

.footer-inner {
  max-width: var(--max);
  margin: 0 auto;
  padding: 42px 32px 48px;
  display: grid;
  grid-template-columns: 1.4fr 1fr 1fr;
  gap: 36px;
}

.footer-mark {
  margin: 0 0 10px;
  font-family: var(--serif);
  font-size: 22px;
  font-weight: 600;
  letter-spacing: -0.02em;
}

.footer-title {
  margin: 0 0 8px;
  font-family: var(--mono);
  font-size: 9px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: #aeb4aa;
}

.footer-note {
  margin: 0 0 8px;
  font-size: 12px;
  line-height: 1.55;
  color: #aeb4aa;
}

footer a {
  color: var(--paper);
  text-decoration-color: rgba(250, 250, 246, 0.4);
}

/* -------------------------------------------------------------------- dialog */

.viewer {
  width: min(1120px, calc(100vw - 32px));
  max-width: 1120px;
  height: min(90vh, 900px);
  max-height: 90vh;
  padding: 0;
  border: 1px solid var(--ink);
  background: var(--surface);
  color: var(--ink);
  overflow: hidden;
}

.viewer::backdrop {
  background: rgba(16, 19, 18, 0.66);
  backdrop-filter: blur(2px);
}

.viewer[open] {
  display: flex;
  flex-direction: column;
}

.viewer-head {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 20px;
  padding: 18px 22px;
  border-bottom: 1px solid var(--rule);
  background: var(--surface);
}

.viewer-head .eyebrow {
  margin-bottom: 5px;
}

.viewer-head h2 {
  margin: 0;
  font-family: var(--serif);
  font-size: clamp(20px, 2.4vw, 30px);
  font-weight: 600;
  line-height: 1.1;
}

.viewer-close {
  flex: 0 0 auto;
  width: 36px;
  height: 36px;
  border: 1px solid var(--rule-strong);
  background: transparent;
  font-size: 24px;
  line-height: 1;
  cursor: pointer;
}

.viewer-close:hover {
  background: var(--ink);
  color: var(--paper);
}

.viewer-body {
  flex: 1 1 auto;
  min-height: 0;
  background: var(--surface-2);
}

.viewer-body iframe {
  width: 100%;
  height: 100%;
  border: 0;
  background: #fff;
}

.viewer-note {
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: flex-start;
  gap: 10px;
  height: 100%;
  padding: 32px;
  font-size: 15px;
  line-height: 1.55;
  color: var(--muted);
}

.viewer-note strong {
  color: var(--ink);
  font-family: var(--serif);
  font-size: 24px;
  font-weight: 600;
}

.viewer-foot {
  display: flex;
  align-items: center;
  flex-wrap: wrap;
  gap: 18px;
  padding: 12px 22px;
  border-top: 1px solid var(--rule);
  background: var(--surface);
  font-family: var(--mono);
  font-size: 9px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
}

.viewer-foot a:not(.btn) {
  color: var(--blue);
  text-decoration: none;
  border-bottom: 1px solid rgba(27, 74, 97, 0.3);
}

.viewer-foot .btn {
  margin-left: auto;
  font-size: 9px;
  min-height: 34px;
}

/* ------------------------------------------------------------------- motion */

.reveal {
  opacity: 1;
  transform: none;
}

@media (prefers-reduced-motion: no-preference) {
  .reveal {
    opacity: 0;
    transform: translateY(14px);
    transition: opacity 600ms ease, transform 600ms cubic-bezier(0.2, 0.7, 0.2, 1);
  }

  body.is-ready .reveal {
    opacity: 1;
    transform: none;
  }

  body.is-ready .cover {
    transition-delay: 90ms;
  }
}

/* ---------------------------------------------------------------- responsive */

@media (max-width: 1180px) {
  .hero {
    grid-template-columns: minmax(0, 1fr) minmax(300px, 0.7fr);
    gap: 40px;
  }

  .workspace {
    grid-template-columns: 160px minmax(0, 1fr);
    gap: 28px;
  }

  .registry-body {
    padding-left: 24px;
    padding-right: 24px;
  }

  .toolbar {
    margin-left: -24px;
    margin-right: -24px;
    padding-left: 24px;
    padding-right: 24px;
  }

  .doc::before {
    left: -24px;
  }
}

@media (max-width: 920px) {
  main {
    padding: 0 20px;
  }

  .topbar {
    padding: 16px 20px;
  }

  .topbar-meta span:first-child {
    display: none;
  }

  .hero {
    grid-template-columns: 1fr;
    gap: 34px;
    padding-top: 44px;
  }

  .cover {
    max-width: 560px;
    min-height: 400px;
  }

  .cover-number {
    font-size: clamp(96px, 18vw, 150px);
  }

  .index-strip {
    grid-template-columns: 1fr 1fr;
  }

  .index-strip div:nth-child(2) {
    border-right: 0;
  }

  .index-strip div:nth-child(-n + 2) {
    border-bottom: 1px solid var(--rule);
  }

  .workspace {
    display: block;
    padding-top: 28px;
  }

  .rail {
    position: static;
    margin-bottom: 20px;
  }

  .rail-title {
    margin-bottom: 8px;
  }

  .rail-nav {
    flex-direction: row;
    overflow-x: auto;
    border-top: 1px solid var(--rule);
    border-bottom: 1px solid var(--rule);
    scrollbar-width: thin;
  }

  .rail-nav a {
    flex: 0 0 auto;
    display: flex;
    gap: 6px;
    padding: 10px 14px;
    border-bottom: 0;
    border-right: 1px solid var(--rule);
    white-space: nowrap;
    font-size: 11px;
  }

  .rail-nav a:hover,
  .rail-nav a.is-active {
    padding-left: 14px;
    background: var(--surface-2);
  }

  .rail-nav a.is-active {
    border-bottom: 0;
    box-shadow: inset 0 -2px 0 var(--red);
  }

  .rail-note {
    display: none;
  }

  .registry-body {
    padding: 0 20px 28px;
  }

  .toolbar {
    margin-left: -20px;
    margin-right: -20px;
    padding: 14px 20px 12px;
  }

  .doc {
    grid-template-columns: 86px minmax(0, 1fr);
    gap: 14px;
  }

  .doc-actions {
    grid-column: 2;
    justify-content: flex-start;
    padding-top: 10px;
  }

  .doc::before {
    left: -20px;
  }

  .changes {
    grid-template-columns: 1fr;
    gap: 18px;
  }

  .dates {
    grid-template-columns: 1fr 1fr;
  }

  .footer-inner {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 640px) {
  .topbar {
    align-items: flex-start;
  }

  .brand-text {
    font-size: 10px;
  }

  .brand-text small {
    display: none;
  }

  .topbar-meta {
    font-size: 8px;
    text-align: right;
  }

  .hero-copy h1 {
    font-size: clamp(38px, 12vw, 56px);
  }

  .hero-year {
    font-size: 10px;
  }

  .cover {
    min-height: 380px;
    padding-left: 38px;
    box-shadow: 7px 7px 0 var(--surface-2);
  }

  .cover::before {
    left: 22px;
  }

  .stamp {
    top: 104px;
    right: 10px;
  }

  .index-strip {
    grid-template-columns: 1fr;
  }

  .index-strip div {
    border-right: 0;
    border-bottom: 1px solid var(--rule);
    padding: 11px 14px;
  }

  .index-strip div:last-child {
    border-bottom: 0;
  }

  .registry-body {
    padding: 0 14px 24px;
  }

  .toolbar {
    margin-left: -14px;
    margin-right: -14px;
    padding: 12px 14px 10px;
  }

  .search-hint {
    display: none;
  }

  .search-clear {
    right: 8px;
  }

  .registry-section {
    scroll-margin-top: 206px;
  }

  .section-head {
    grid-template-columns: 1fr;
    gap: 6px;
  }

  .section-num {
    padding-top: 0;
  }

  .doc {
    grid-template-columns: 1fr;
    gap: 9px;
    padding: 18px 0;
  }

  .doc-code {
    flex-direction: row;
    align-items: center;
    gap: 8px;
    padding-top: 0;
  }

  .doc-actions {
    grid-column: 1;
    padding-top: 4px;
  }

  .doc::before {
    left: -14px;
    top: 18px;
    bottom: 18px;
  }

  .dates {
    grid-template-columns: 1fr;
  }

  .change-list div {
    grid-template-columns: 78px minmax(0, 1fr);
  }

  .sources-grid {
    grid-template-columns: 1fr;
  }

  .footer-inner {
    grid-template-columns: 1fr;
    gap: 24px;
    padding: 34px 20px 40px;
  }

  .viewer {
    width: 100vw;
    height: 94vh;
    max-height: 94vh;
    border: 0;
  }

  .viewer-head {
    padding: 14px 16px;
  }

  .viewer-foot {
    gap: 12px;
    padding: 10px 16px;
  }

  .viewer-foot .btn {
    margin-left: 0;
  }
}

/* --------------------------------------------------------------------- print */

@media print {
  body::before,
  .topbar,
  .rail,
  .toolbar,
  .doc-actions,
  .stamp,
  .cover-foot,
  .viewer,
  .skip {
    display: none !important;
  }

  body {
    background: #fff;
    color: #000;
    font-size: 11pt;
  }

  main {
    max-width: none;
    padding: 0;
  }

  .hero {
    display: block;
    padding: 0 0 20pt;
  }

  .hero-copy h1 {
    font-size: 30pt;
  }

  .cover {
    display: none;
  }

  .workspace {
    display: block;
  }

  .registry-body {
    border: 0;
    padding: 0;
  }

  .doc,
  .registry-section {
    break-inside: avoid;
  }

  .doc {
    grid-template-columns: 70pt 1fr;
  }

  .doc::before {
    display: none;
  }

  a {
    color: #000;
    text-decoration: none;
  }

  .badge {
    border: 1px solid #000;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  *,
  *::before,
  *::after {
    transition-duration: 0.001ms !important;
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
  }
}

/* ==========================================================================
   Новые разделы: главная, задания, карта экзамена
   ========================================================================== */

:root {
  --ochre: #8a6a2f;
  --ochre-soft: #efe5d1;
}

/* ------------------------------------------------------------- site nav */

.topbar {
  gap: 24px;
}

.site-nav {
  display: flex;
  align-items: center;
  gap: 16px;
  margin-left: 8px;
}

.site-nav a {
  font-family: var(--mono);
  font-size: 9px;
  letter-spacing: 0.11em;
  text-transform: uppercase;
  color: var(--muted);
  text-decoration: none;
  padding: 6px 0;
  border-bottom: 2px solid transparent;
  white-space: nowrap;
}

.site-nav a:hover {
  color: var(--ink);
}

.site-nav a.is-active {
  color: var(--ink);
  border-bottom-color: var(--red);
}

/* ----------------------------------------------------------- breadcrumbs */

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 7px;
  margin: 0 0 20px;
  font-family: var(--mono);
  font-size: 8px;
  letter-spacing: 0.07em;
  text-transform: uppercase;
  color: var(--muted);
}

.breadcrumb a {
  color: var(--muted);
  text-decoration: none;
  border-bottom: 1px solid var(--rule);
}

.breadcrumb a:hover {
  color: var(--ink);
  border-bottom-color: var(--ink);
}

.breadcrumb span[aria-current="page"] {
  color: var(--ink);
}

.crumb-sep {
  color: var(--rule-strong);
}

/* ---------------------------------------------------------- credit banner */

.credit-banner {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1.12fr) minmax(360px, 0.88fr);
  align-items: end;
  gap: clamp(28px, 4vw, 56px);
  margin: clamp(24px, 4vw, 44px) 0 0;
  padding: clamp(28px, 4.5vw, 56px);
  background: #f3ecdd;
  border: 1px solid #cbbb9c;
  border-top: 7px solid var(--red);
  color: var(--ink);
}

.credit-banner-copy {
  min-width: 0;
}

.credit-banner .eyebrow {
  margin-bottom: 14px;
  color: var(--red-dark);
}

.credit-banner h2 {
  margin: 0;
  font-family: var(--serif);
  font-size: clamp(42px, 6.4vw, 92px);
  font-weight: 600;
  line-height: 0.92;
  letter-spacing: -0.045em;
  text-wrap: balance;
  color: var(--ink);
}

.credit-banner h2 em {
  font-style: normal;
  color: var(--red);
}

.credit-agencies {
  margin: 12px 0 0;
  font-family: var(--mono);
  font-size: 11px;
  font-weight: 500;
  line-height: 1.4;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: #8a6a45;
}

.credit-lead {
  max-width: 58ch;
  margin: 24px 0 0;
  font-size: 15px;
  line-height: 1.55;
  color: #454b45;
}

.credit-lead a {
  color: var(--red-dark);
  text-decoration-color: var(--red);
  text-decoration-thickness: 2px;
  text-underline-offset: 3px;
}

.credit-lead a:hover {
  color: var(--ink);
}

.credit-fine {
  max-width: 68ch;
  margin: 18px 0 0;
  font-family: var(--mono);
  font-size: 9px;
  line-height: 1.65;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: #767b6d;
}

.credit-links {
  display: flex;
  flex-direction: column;
  border-top: 1px solid #cdbfa3;
}

.credit-link {
  display: grid;
  grid-template-columns: 30px minmax(0, 1fr) auto;
  align-items: center;
  gap: 14px;
  padding: 16px 0;
  border-bottom: 1px solid #cdbfa3;
  color: var(--ink);
  text-decoration: none;
  transition: color 150ms ease, padding 150ms ease;
}

.credit-link:hover {
  padding-left: 6px;
  color: var(--red-dark);
}

.credit-link-index {
  font-family: var(--mono);
  font-size: 9px;
  letter-spacing: 0.1em;
  color: var(--ochre);
}

.credit-link-body {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 0;
}

.credit-link-label {
  font-family: var(--mono);
  font-size: 8px;
  letter-spacing: 0.13em;
  text-transform: uppercase;
  color: var(--ochre);
}

.credit-link strong {
  font-family: var(--sans);
  font-size: 17px;
  font-weight: 600;
  line-height: 1.2;
}

.credit-link-desc {
  font-size: 12px;
  line-height: 1.4;
  color: var(--muted);
}

.credit-link-arrow {
  font-size: 19px;
  line-height: 1;
  color: var(--red);
  transition: transform 150ms ease;
}

.credit-link:hover .credit-link-arrow {
  transform: translate(2px, -2px);
}

.credit-link:hover .credit-link-desc {
  color: var(--ink);
}

.credit-banner :focus-visible {
  outline: 2px solid var(--blue);
  outline-offset: 4px;
}

/* -------------------------------------------------------------- home hero */

.home-hero {
  display: grid;
  grid-template-columns: minmax(0, 1.04fr) minmax(380px, 0.96fr);
  align-items: center;
  gap: clamp(32px, 5vw, 72px);
  padding: clamp(36px, 6vw, 78px) 0 clamp(36px, 5vw, 60px);
}

.home-hero-copy h1 {
  margin: 0;
  font-family: var(--serif);
  font-size: clamp(44px, 6vw, 82px);
  font-weight: 600;
  line-height: 0.97;
  letter-spacing: -0.035em;
  text-wrap: balance;
}

.home-hero-copy .lead {
  margin-top: 22px;
}

.map-panel {
  display: flex;
  flex-direction: column;
  min-height: 0;
  padding: 20px 20px 18px;
  background: var(--surface);
  border: 1px solid var(--rule-strong);
  box-shadow: 10px 10px 0 var(--surface-2);
}

.map-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--rule);
  font-family: var(--mono);
  font-size: 9px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
}

.map-progress {
  color: var(--ink);
  font-variant-numeric: tabular-nums;
}

.task-map {
  display: grid;
  grid-template-columns: repeat(9, 1fr);
  gap: 5px;
  margin-top: 14px;
}

.task-cell {
  position: relative;
  display: grid;
  place-items: center;
  aspect-ratio: 1;
  min-width: 0;
  border: 1px solid var(--rule);
  border-top-width: 3px;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--mono);
  font-size: 12px;
  font-weight: 500;
  line-height: 1;
  text-decoration: none;
  font-variant-numeric: tabular-nums;
  transition: background 140ms ease, color 140ms ease, border-color 140ms ease;
}

.task-cell:hover,
.task-cell:focus-visible {
  background: var(--ink);
  color: var(--paper);
  border-color: var(--ink);
}

.task-cell.is-current {
  background: var(--ink);
  color: var(--paper);
  border-color: var(--ink);
}

.task-cell--merged {
  box-shadow: inset 0 -3px 0 var(--red);
}

.task-cell--range {
  grid-column: span 3;
  aspect-ratio: auto;
  padding: 0 8px;
  font-size: 13px;
  letter-spacing: 0.01em;
  white-space: nowrap;
}

.task-map--index .task-cell--range {
  font-size: 14px;
}

.map-merge-note {
  margin: 8px 0 0;
  font-family: var(--mono);
  font-size: 8px;
  line-height: 1.45;
  letter-spacing: 0.02em;
  color: var(--muted);
}

.map-merge-note span {
  color: var(--red);
  font-weight: 600;
}

.task-cell--digital {
  border-top-color: var(--blue);
}

.task-cell--theory {
  border-top-color: var(--red);
}

.task-cell--algo {
  border-top-color: var(--green);
}

.task-cell--it {
  border-top-color: var(--ochre);
}

.task-cell.is-done::after {
  content: "";
  position: absolute;
  top: 4px;
  right: 4px;
  width: 4px;
  height: 4px;
  border-radius: 50%;
  background: var(--green);
}

.task-cell.is-current.is-done::after {
  background: var(--paper);
}

.map-caption {
  min-height: 30px;
  margin: 12px 0 0;
  font-size: 12px;
  line-height: 1.4;
  color: var(--muted);
}

.map-caption strong {
  color: var(--ink);
  font-weight: 600;
}

.map-legend {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 14px;
  margin-top: 10px;
  padding-top: 12px;
  border-top: 1px solid var(--rule);
}

.legend-item {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  font-family: var(--mono);
  font-size: 7px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--muted);
}

.legend-dot {
  width: 7px;
  height: 3px;
  background: var(--rule-strong);
}

.legend-dot--digital {
  background: var(--blue);
}

.legend-dot--theory {
  background: var(--red);
}

.legend-dot--algo {
  background: var(--green);
}

.legend-dot--it {
  background: var(--ochre);
}

.map-link {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  align-self: flex-start;
  margin-top: 14px;
  font-family: var(--mono);
  font-size: 8px;
  letter-spacing: 0.07em;
  text-transform: uppercase;
  text-decoration: none;
  color: var(--ink);
  border-bottom: 1px solid var(--rule-strong);
}

/* ----------------------------------------------------------------- facts */

.facts-wrap {
  border-top: 1px solid var(--ink);
  border-bottom: 1px solid var(--ink);
}

.facts {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
}

.facts div {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 15px 18px;
  border-right: 1px solid var(--rule);
}

.facts div:last-child {
  border-right: 0;
}

.facts strong {
  font-family: var(--serif);
  font-size: 30px;
  font-weight: 600;
  line-height: 1;
}

.facts span {
  font-family: var(--mono);
  font-size: 8px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
}

.facts-note {
  margin: 9px 0 0;
  font-size: 11px;
  line-height: 1.5;
  color: var(--muted);
}

/* ------------------------------------------------------------ home section */

.home-section {
  padding: 56px 0 10px;
  border-top: 1px solid var(--rule);
  margin-top: 42px;
}

.home-section:first-of-type {
  margin-top: 0;
  border-top: 0;
  padding-top: 42px;
}

.section-head--home {
  margin-bottom: 24px;
}

.section-head--home .section-copy h2 {
  font-size: clamp(32px, 3.6vw, 48px);
}

/* ------------------------------------------------------------ task groups */

.task-group {
  margin-top: 34px;
}

.task-group:first-of-type {
  margin-top: 0;
}

.task-group-head {
  display: grid;
  grid-template-columns: 56px minmax(0, 1fr);
  gap: 16px;
  align-items: start;
  padding: 0 0 16px;
  border-bottom: 1px solid var(--ink);
}

.task-group-marker {
  display: grid;
  place-items: center;
  width: 36px;
  height: 36px;
  margin-top: 4px;
  background: var(--ink);
  color: var(--paper);
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.04em;
}

.task-group-marker--digital {
  background: var(--blue);
}

.task-group-marker--theory {
  background: var(--red);
}

.task-group-marker--algo {
  background: var(--green);
}

.task-group-marker--it {
  background: var(--ochre);
}

.task-group-copy .eyebrow {
  margin-bottom: 5px;
  color: var(--red);
}

.task-group-copy h2 {
  margin: 0;
  font-family: var(--serif);
  font-size: clamp(25px, 2.8vw, 36px);
  font-weight: 600;
  line-height: 1.08;
  letter-spacing: -0.02em;
}

.task-group-copy p {
  max-width: 72ch;
  margin: 7px 0 0;
  font-size: 13px;
  line-height: 1.5;
  color: var(--muted);
}

.task-group-note {
  margin-top: 8px !important;
  font-size: 12px !important;
}

.task-group-note a {
  color: var(--red);
  text-decoration: none;
  border-bottom: 1px solid rgba(194, 46, 36, 0.3);
}

.task-cards {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  margin-top: 12px;
  background: var(--rule);
  border: 1px solid var(--rule);
}

.task-cards--digital,
.task-cards--it {
  grid-template-columns: repeat(2, 1fr);
}

.task-card {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 7px;
  min-height: 178px;
  padding: 16px 16px 14px;
  background: var(--surface);
  color: var(--ink);
  text-decoration: none;
  border-top: 3px solid var(--rule-strong);
  transition: background 150ms ease;
}

.task-card:hover {
  background: var(--surface-2);
}

.task-card--digital {
  border-top-color: var(--blue);
}

.task-card--theory {
  border-top-color: var(--red);
}

.task-card--algo {
  border-top-color: var(--green);
}

.task-card--it {
  border-top-color: var(--ochre);
}

.task-card--merged {
  background: linear-gradient(180deg, var(--red-soft), var(--surface) 42%);
}

.task-card--merged-part {
  border-top-style: dashed;
}

.task-card-flag {
  align-self: flex-start;
  padding: 2px 5px;
  border: 1px solid rgba(194, 46, 36, 0.35);
  background: var(--red-soft);
  color: var(--red);
  font-family: var(--mono);
  font-size: 7px;
  letter-spacing: 0.06em;
  line-height: 1.3;
  text-transform: uppercase;
  white-space: nowrap;
}

.task-card.is-done::after {
  content: "✓";
  position: absolute;
  top: 12px;
  right: 12px;
  display: grid;
  place-items: center;
  width: 17px;
  height: 17px;
  border: 1px solid var(--green);
  color: var(--green);
  font-family: var(--mono);
  font-size: 10px;
  line-height: 1;
  background: var(--surface);
}

.task-card-top {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 8px;
}

.task-card-num {
  font-family: var(--serif);
  font-size: 31px;
  font-weight: 600;
  line-height: 0.9;
  letter-spacing: -0.04em;
}

.task-card-points {
  font-family: var(--mono);
  font-size: 7px;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--muted);
  white-space: nowrap;
}

.task-card-title {
  font-family: var(--serif);
  font-size: 19px;
  font-weight: 600;
  line-height: 1.15;
  letter-spacing: -0.012em;
}

.task-card-summary {
  display: -webkit-box;
  overflow: hidden;
  -webkit-line-clamp: 3;
  -webkit-box-orient: vertical;
  font-size: 12px;
  line-height: 1.45;
  color: var(--muted);
}

.task-card-foot {
  margin-top: auto;
  padding-top: 8px;
  font-family: var(--mono);
  font-size: 7px;
  line-height: 1.4;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--muted);
  border-top: 1px solid var(--rule);
}

/* --------------------------------------------------------------- changes */

.changes--home {
  margin-top: 48px;
}

.change-list a {
  color: var(--red);
  text-decoration: none;
  border-bottom: 1px solid rgba(194, 46, 36, 0.3);
}

/* ----------------------------------------------------------------- steps */

.steps-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: var(--rule);
  border: 1px solid var(--rule);
}

.step-card {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 22px;
  background: var(--surface);
}

.step-num {
  font-family: var(--serif);
  font-size: 42px;
  font-weight: 600;
  line-height: 0.9;
  color: var(--red);
}

.step-card h3 {
  margin: 0;
  font-family: var(--serif);
  font-size: 21px;
  font-weight: 600;
  line-height: 1.2;
}

.step-card p {
  margin: 0;
  font-size: 13px;
  line-height: 1.5;
  color: var(--muted);
}

.step-card .text-link {
  align-self: flex-start;
  margin-top: auto;
  padding-top: 12px;
  font-size: 8px;
  text-transform: uppercase;
  text-decoration: none;
  border-bottom: 1px solid var(--rule-strong);
  color: var(--blue);
}

/* ------------------------------------------------------------- materials */

.materials-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1px;
  background: var(--rule);
  border: 1px solid var(--rule);
}

.material-card {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 7px;
  min-height: 170px;
  padding: 18px;
  background: var(--surface);
  color: var(--ink);
  text-decoration: none;
  transition: background 150ms ease;
}

.material-card:hover {
  background: var(--surface-2);
}

.material-card--accent {
  background: var(--ink);
  color: var(--paper);
}

.material-card--accent:hover {
  background: #1b1f1d;
}

.material-label {
  font-family: var(--mono);
  font-size: 7px;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--red);
}

.material-card--accent .material-label {
  color: #f08a80;
}

.material-title {
  font-family: var(--serif);
  font-size: 21px;
  font-weight: 600;
  line-height: 1.15;
  letter-spacing: -0.02em;
}

.material-desc {
  font-size: 12px;
  line-height: 1.45;
  color: var(--muted);
}

.material-card--accent .material-desc {
  color: #b9c0b5;
}

.material-arrow {
  position: absolute;
  top: 16px;
  right: 16px;
  font-family: var(--mono);
  font-size: 13px;
  color: var(--muted);
}

.material-card--accent .material-arrow {
  color: var(--paper);
}

.documents-cta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  margin-top: 18px;
  padding: 22px;
  border: 1px solid var(--rule-strong);
  background: var(--surface);
}

.documents-cta h3 {
  margin: 0 0 6px;
  font-family: var(--serif);
  font-size: 25px;
  font-weight: 600;
  line-height: 1.15;
}

.documents-cta p {
  max-width: 70ch;
  margin: 0;
  font-size: 13px;
  line-height: 1.5;
  color: var(--muted);
}

.documents-cta .eyebrow {
  margin-bottom: 5px;
  color: var(--red);
}

/* ----------------------------------------------------------- closing band */

.closing-band {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 32px;
  margin-top: 56px;
  padding: 32px;
  background: var(--ink);
  color: var(--paper);
}

.closing-band h2 {
  margin: 0 0 8px;
  font-family: var(--serif);
  font-size: clamp(28px, 3vw, 40px);
  font-weight: 600;
  line-height: 1.05;
  letter-spacing: -0.025em;
}

.closing-band p {
  max-width: 62ch;
  margin: 0;
  font-size: 13px;
  line-height: 1.5;
  color: #b9c0b5;
}

.closing-band .eyebrow {
  margin-bottom: 6px;
  color: #f08a80;
}

.closing-band--light {
  background: var(--surface);
  color: var(--ink);
  border: 1px solid var(--rule);
}

.closing-band--light p {
  color: var(--muted);
}

.closing-band--light .eyebrow {
  color: var(--red);
}

.closing-band .btn-primary {
  flex: 0 0 auto;
}

.closing-band .btn-ghost {
  flex: 0 0 auto;
  border-color: var(--rule-strong);
  color: var(--ink);
}

/* ------------------------------------------------------------- page hero */

.page-hero {
  padding: 34px 0 28px;
  border-bottom: 2px solid var(--ink);
}

.page-hero h1 {
  max-width: 18ch;
  margin: 0;
  font-family: var(--serif);
  font-size: clamp(42px, 5.4vw, 70px);
  font-weight: 600;
  line-height: 0.98;
  letter-spacing: -0.035em;
  text-wrap: balance;
}

.page-hero .lead {
  max-width: 65ch;
  margin-top: 18px;
}

.progress-panel {
  max-width: 640px;
  margin-top: 24px;
  padding: 14px 16px;
  background: var(--surface);
  border: 1px solid var(--rule);
}

.progress-panel-head,
.progress-panel-foot {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.progress-label {
  font-family: var(--mono);
  font-size: 8px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
}

.progress-line {
  height: 5px;
  margin: 10px 0;
  background: var(--rule);
  overflow: hidden;
}

.progress-line span {
  display: block;
  width: 0;
  height: 100%;
  background: var(--red);
  transition: width 220ms ease;
}

.progress-note {
  margin: 0;
  font-family: var(--mono);
  font-size: 8px;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--muted);
}

.progress-panel-foot .text-link {
  margin: 0;
  padding: 0;
  border: 0;
  background: transparent;
  font-family: var(--mono);
  font-size: 8px;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--muted);
  text-decoration: underline;
  text-underline-offset: 3px;
  cursor: pointer;
}

/* ---------------------------------------------------------- task index */

.task-index-section {
  padding: 34px 0 0;
}

.task-index-head {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: 24px;
  margin-bottom: 14px;
}

.task-index-head h2 {
  margin: 0;
  font-family: var(--serif);
  font-size: clamp(28px, 3vw, 40px);
  font-weight: 600;
  line-height: 1.05;
}

.task-index-count {
  margin: 0;
  font-family: var(--mono);
  font-size: 8px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
}

.chips--tasks {
  margin-bottom: 16px;
}

.chips--tasks .chip {
  font-size: 8px;
  padding: 6px 9px;
}

.task-map-row {
  display: flex;
  align-items: flex-start;
  gap: 28px;
  margin: 18px 0 4px;
}

.task-map--index {
  flex: 0 1 720px;
  margin: 0;
}

.task-map--index .task-cell {
  font-size: 12px;
}

.task-map-side {
  flex: 1 1 260px;
  max-width: 330px;
  padding-left: 24px;
  border-left: 1px solid var(--rule);
}

.task-map-side ul {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 8px;
}

.task-map-side li {
  display: grid;
  grid-template-columns: 10px minmax(0, 1fr);
  gap: 8px;
  align-items: baseline;
  font-size: 12px;
  line-height: 1.35;
}

.task-map-side li em {
  grid-column: 2;
  font-family: var(--mono);
  font-size: 8px;
  font-style: normal;
  letter-spacing: 0.03em;
  color: var(--muted);
}

.map-side-label {
  color: var(--ink);
}

.map-side-note {
  margin: 14px 0 0;
  padding-top: 12px;
  border-top: 1px solid var(--rule);
  font-size: 11px;
  line-height: 1.5;
  color: var(--muted);
}

/* ------------------------------------------------------------- task page */

.task-hero {
  display: grid;
  grid-template-columns: 132px minmax(0, 1fr);
  gap: 24px;
  align-items: start;
  padding: 34px 0 30px;
  border-bottom: 2px solid var(--ink);
}

.task-number {
  font-family: var(--serif);
  font-size: clamp(82px, 10vw, 138px);
  font-weight: 600;
  line-height: 0.72;
  letter-spacing: -0.07em;
  color: var(--ink);
}

.task-number--range {
  font-size: clamp(30px, 4vw, 52px);
  line-height: 0.95;
  letter-spacing: -0.055em;
  white-space: nowrap;
}

.task-hero-copy .eyebrow {
  margin-bottom: 8px;
  color: var(--red);
}

.task-hero-copy h1 {
  margin: 0;
  font-family: var(--serif);
  font-size: clamp(38px, 5vw, 64px);
  font-weight: 600;
  line-height: 1.02;
  letter-spacing: -0.03em;
  text-wrap: balance;
}

.task-subtitle {
  margin: 8px 0 0;
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
}

.task-hero-copy .lead {
  max-width: 62ch;
  margin-top: 16px;
}

.task-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 7px;
  margin-top: 18px;
}

.badge-section {
  padding: 3px 6px;
  font-size: 8px;
}

.badge-section--digital {
  color: var(--blue);
  background: var(--blue-soft);
}

.badge-section--theory {
  color: var(--red);
  background: var(--red-soft);
}

.badge-section--algo {
  color: var(--green);
  background: var(--green-soft);
}

.badge-section--it {
  color: var(--ochre);
  background: var(--ochre-soft);
}

.badge-answer {
  color: var(--muted);
  background: var(--surface-2);
  padding: 3px 6px;
  font-size: 8px;
}

.task-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 264px;
  gap: clamp(28px, 4vw, 56px);
  align-items: start;
  padding: 0 0 40px;
}

.task-main {
  min-width: 0;
}

.task-block {
  padding: 24px 0;
  border-bottom: 1px solid var(--rule);
}

.task-block h2 {
  margin: 0 0 12px;
  font-family: var(--serif);
  font-size: clamp(24px, 2.5vw, 31px);
  font-weight: 600;
  line-height: 1.1;
  letter-spacing: -0.02em;
}

.task-checked {
  max-width: 76ch;
  margin: 0;
  font-size: 15px;
  line-height: 1.55;
  color: #333934;
}

.task-source {
  margin: 10px 0 0;
  font-family: var(--mono);
  font-size: 8px;
  line-height: 1.5;
  letter-spacing: 0.02em;
  text-transform: uppercase;
  color: var(--muted);
}

.task-source a {
  color: var(--blue);
  text-decoration: none;
  border-bottom: 1px solid rgba(27, 74, 97, 0.3);
}

.task-list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 7px;
}

.task-list li {
  position: relative;
  padding-left: 17px;
  font-size: 14px;
  line-height: 1.5;
  color: #333934;
}

.task-list li::before {
  content: "";
  position: absolute;
  top: 9px;
  left: 0;
  width: 6px;
  height: 1px;
  background: var(--rule-strong);
}

.task-list--columns {
  grid-template-columns: 1fr 1fr;
  gap: 7px 24px;
}

.task-list--mistakes li::before {
  background: var(--red);
}

.task-steps {
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: step;
  display: grid;
  gap: 10px;
}

.task-steps li {
  counter-increment: step;
  display: grid;
  grid-template-columns: 24px 1fr;
  gap: 10px;
  font-size: 14px;
  line-height: 1.5;
  color: #333934;
}

.task-steps li::before {
  content: counter(step, decimal-leading-zero);
  font-family: var(--mono);
  font-size: 9px;
  letter-spacing: 0.04em;
  color: var(--red);
  padding-top: 3px;
}

.formula-list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 1px;
  background: var(--rule);
  border: 1px solid var(--rule);
}

.formula-list li {
  padding: 11px 13px;
  background: var(--surface-2);
  font-family: var(--mono);
  font-size: 12px;
  line-height: 1.45;
  color: var(--ink);
  overflow-x: auto;
}

.callout {
  display: flex;
  gap: 14px;
  align-items: flex-start;
  margin: 22px 0 0;
  padding: 14px 16px;
  border-left: 2px solid var(--red);
  background: var(--red-soft);
}

.callout-label {
  flex: 0 0 auto;
  font-family: var(--mono);
  font-size: 8px;
  letter-spacing: 0.1em;
  color: var(--red);
  padding-top: 3px;
}

.callout p {
  margin: 0;
  font-size: 13px;
  line-height: 1.5;
  color: #4a2a27;
}

.task-note {
  margin: 16px 0 0;
  padding: 10px 12px;
  border: 1px solid var(--rule);
  background: var(--surface-2);
  font-family: var(--mono);
  font-size: 9px;
  line-height: 1.5;
  color: var(--muted);
}

.practice-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: var(--rule);
  border: 1px solid var(--rule);
}

.practice-link {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 14px;
  background: var(--surface);
  color: var(--ink);
  text-decoration: none;
  transition: background 150ms ease;
}

.practice-link:hover {
  background: var(--surface-2);
}

.practice-label {
  font-family: var(--mono);
  font-size: 7px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--red);
}

.practice-title {
  font-family: var(--serif);
  font-size: 17px;
  font-weight: 600;
  line-height: 1.2;
}

.practice-arrow {
  position: absolute;
  top: 12px;
  right: 12px;
  font-family: var(--mono);
  font-size: 11px;
  color: var(--muted);
}

.practice-note {
  margin: 9px 0 0;
  font-size: 11px;
  line-height: 1.45;
  color: var(--muted);
}

.related-links {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding: 20px 0;
  border-bottom: 1px solid var(--rule);
}

.related-label {
  font-family: var(--mono);
  font-size: 8px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
  margin-right: 4px;
}

.related-link {
  padding: 5px 8px;
  border: 1px solid var(--rule);
  font-size: 11px;
  line-height: 1.3;
  text-decoration: none;
  color: var(--blue);
  background: var(--surface);
}

.related-link:hover {
  border-color: var(--blue);
}

.prev-next {
  display: flex;
  justify-content: space-between;
  gap: 16px;
  padding: 22px 0 0;
}

.prev-next-link {
  display: flex;
  flex-direction: column;
  gap: 4px;
  max-width: 48%;
  text-decoration: none;
  color: var(--ink);
}

.prev-next-link span {
  font-family: var(--mono);
  font-size: 8px;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  color: var(--muted);
}

.prev-next-link strong {
  font-family: var(--serif);
  font-size: 17px;
  font-weight: 600;
  line-height: 1.2;
}

.prev-next-link--next {
  margin-left: auto;
  text-align: right;
}

.task-aside {
  position: sticky;
  top: 20px;
  display: grid;
  gap: 12px;
}

.aside-card {
  padding: 14px;
  background: var(--surface);
  border: 1px solid var(--rule);
}

.aside-head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 8px;
  padding-bottom: 9px;
  border-bottom: 1px solid var(--rule);
  font-family: var(--mono);
  font-size: 8px;
  letter-spacing: 0.07em;
  text-transform: uppercase;
  color: var(--muted);
}

.task-map--compact {
  grid-template-columns: repeat(5, 1fr);
  gap: 4px;
  margin-top: 10px;
}

.task-cell--compact {
  font-size: 10px;
}

.aside-label {
  margin: 0 0 9px;
  font-family: var(--mono);
  font-size: 8px;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  color: var(--muted);
}

.aside-link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  padding: 7px 0;
  border-top: 1px solid var(--rule);
  font-size: 11px;
  line-height: 1.3;
  text-decoration: none;
  color: var(--ink);
}

.aside-link:hover {
  color: var(--red);
}

.aside-card .progress-toggle {
  width: 100%;
  margin-top: 2px;
}

.aside-card--progress .progress-note {
  margin: 9px 0 7px;
  text-transform: none;
  letter-spacing: 0.02em;
}

.aside-card--progress .progress-line {
  margin: 0;
}

/* --------------------------------------------------------------- responsive */

@media (max-width: 1180px) {
  .topbar {
    flex-wrap: wrap;
    gap: 14px 24px;
  }

  .site-nav {
    order: 3;
    flex-basis: 100%;
    margin-left: 0;
    padding-top: 9px;
    border-top: 1px solid var(--rule);
    overflow-x: auto;
  }

  .site-nav a {
    padding: 4px 0;
  }

  .topbar-meta {
    margin-left: auto;
  }

  .home-hero {
    grid-template-columns: minmax(0, 1fr) minmax(340px, 0.85fr);
    gap: 36px;
  }

  .task-cards,
  .materials-grid {
    grid-template-columns: repeat(2, 1fr);
  }

  .task-layout {
    grid-template-columns: minmax(0, 1fr) 240px;
    gap: 28px;
  }
}

@media (max-width: 920px) {
  .credit-banner {
    grid-template-columns: minmax(0, 1fr);
    align-items: start;
    gap: 32px;
  }

  .credit-links {
    max-width: 560px;
    min-width: 0;
  }

  .home-hero {
    grid-template-columns: 1fr;
    gap: 30px;
    padding-top: 32px;
  }

  .map-panel {
    max-width: 560px;
    width: 100%;
  }

  .task-map {
    grid-template-columns: repeat(9, 1fr);
  }

  .facts {
    grid-template-columns: 1fr 1fr;
  }

  .facts div:nth-child(2) {
    border-right: 0;
  }

  .facts div:nth-child(-n + 2) {
    border-bottom: 1px solid var(--rule);
  }

  .steps-grid {
    grid-template-columns: 1fr;
  }

  .documents-cta,
  .closing-band {
    flex-direction: column;
    align-items: flex-start;
  }

  .task-hero {
    grid-template-columns: 88px minmax(0, 1fr);
    gap: 16px;
  }

  .task-number {
    font-size: 78px;
  }

  .task-layout {
    grid-template-columns: 1fr;
  }

  .task-aside {
    position: static;
    grid-template-columns: 1fr 1fr;
    order: 2;
  }

  .task-aside .aside-card:first-child {
    grid-column: 1 / -1;
  }

  .task-aside .aside-card:last-child {
    display: none;
  }

  .task-list--columns {
    grid-template-columns: 1fr;
  }

  .task-map--compact {
    grid-template-columns: repeat(9, 1fr);
  }

  .task-cell--compact {
    font-size: 9px;
  }

  .task-map-row {
    flex-direction: column;
    gap: 18px;
  }

  .task-map-side {
    max-width: none;
    width: 100%;
    padding-left: 0;
    padding-top: 14px;
    border-left: 0;
    border-top: 1px solid var(--rule);
  }

  .task-map-side ul {
    grid-template-columns: 1fr 1fr;
  }

  .page-hero h1 {
    max-width: 100%;
  }
}

@media (max-width: 640px) {
  .credit-banner {
    margin-top: 20px;
    padding: 24px 20px;
    border-top-width: 5px;
  }

  .credit-banner h2 {
    font-size: clamp(32px, 9.5vw, 48px);
  }

  .credit-lead {
    margin-top: 18px;
    font-size: 14px;
  }

  .credit-link {
    padding: 14px 0;
  }

  .site-nav {
    gap: 14px;
  }

  .site-nav a {
    font-size: 8px;
  }

  .home-hero-copy h1 {
    font-size: clamp(38px, 12vw, 56px);
  }

  .task-map {
    gap: 4px;
  }

  .task-cell {
    font-size: 10px;
    border-top-width: 2px;
  }

  .task-map--compact,
  .task-map--index {
    grid-template-columns: repeat(9, 1fr);
  }

  .task-map--index {
    max-width: none;
  }

  .task-map-side ul {
    grid-template-columns: 1fr;
  }

  .task-cell--compact {
    font-size: 8px;
  }

  .facts {
    grid-template-columns: 1fr 1fr;
  }

  .facts div {
    padding: 11px 12px;
  }

  .facts strong {
    font-size: 24px;
  }

  .facts span {
    font-size: 7px;
  }

  .task-cards,
  .materials-grid {
    grid-template-columns: 1fr;
  }

  .task-card {
    min-height: 0;
  }

  .task-group-head {
    grid-template-columns: 44px minmax(0, 1fr);
    gap: 10px;
  }

  .task-group-copy h2 {
    font-size: 27px;
  }

  .task-hero {
    grid-template-columns: 1fr;
    gap: 8px;
    padding-top: 24px;
  }

  .task-number {
    font-size: 64px;
    line-height: 0.8;
  }

  .task-hero-copy h1 {
    font-size: clamp(36px, 11vw, 48px);
  }

  .task-aside {
    grid-template-columns: 1fr;
  }

  .task-aside .aside-card:first-child {
    grid-column: auto;
  }

  .practice-grid {
    grid-template-columns: 1fr;
  }

  .prev-next {
    flex-direction: column;
  }

  .prev-next-link,
  .prev-next-link--next {
    max-width: 100%;
    text-align: left;
    margin-left: 0;
  }

  .documents-cta,
  .closing-band {
    padding: 22px;
  }

  .page-hero {
    padding-top: 24px;
  }

  .task-index-head {
    align-items: flex-start;
    flex-direction: column;
    gap: 8px;
  }
}

/* ==========================================================================
   Задание 1: теория и способы решения
   ========================================================================== */

.task-toc {
  position: sticky;
  top: 0;
  z-index: 8;
  display: flex;
  align-items: center;
  gap: 18px;
  margin: 0 0 8px;
  padding: 10px 0;
  background: var(--paper);
  border-top: 1px solid var(--rule);
  border-bottom: 1px solid var(--rule);
  overflow-x: auto;
}

.task-toc-label {
  flex: 0 0 auto;
  font-family: var(--mono);
  font-size: 8px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
}

.task-toc a {
  flex: 0 0 auto;
  font-family: var(--mono);
  font-size: 8px;
  letter-spacing: 0.07em;
  text-transform: uppercase;
  text-decoration: none;
  color: var(--ink);
  padding-bottom: 2px;
  border-bottom: 1px solid var(--rule-strong);
}

.task-toc a:hover {
  color: var(--red);
  border-bottom-color: var(--red);
}

#theory,
#methods,
#mistakes,
#practice {
  scroll-margin-top: 54px;
}

.block-head {
  margin-bottom: 20px;
}

.block-head .eyebrow {
  color: var(--red);
  margin-bottom: 6px;
}

.block-head h2 {
  margin: 0;
  font-family: var(--serif);
  font-size: clamp(28px, 3.1vw, 40px);
  font-weight: 600;
  line-height: 1.06;
  letter-spacing: -0.025em;
}

.block-head h3 {
  margin: 0;
  font-family: var(--serif);
  font-size: 24px;
  font-weight: 600;
  line-height: 1.1;
}

.block-head--small {
  margin-bottom: 14px;
}

.block-head--small h3 {
  font-size: clamp(23px, 2.4vw, 30px);
}

.block-head--small p:last-child {
  max-width: 70ch;
  margin: 7px 0 0;
  font-size: 13px;
  line-height: 1.5;
  color: var(--muted);
}

.block-lead {
  max-width: 74ch;
  margin: 9px 0 0;
  font-size: 14px;
  line-height: 1.5;
  color: var(--muted);
}

.mini-label {
  margin: 0 0 9px;
  font-family: var(--mono);
  font-size: 8px;
  letter-spacing: 0.09em;
  text-transform: uppercase;
  color: var(--muted);
}

/* ------------------------------------------------------------- theory */

.theory-checklist {
  margin: 0 0 20px;
  padding: 16px 18px;
  background: var(--surface-2);
  border: 1px solid var(--rule);
}

.check-list {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 6px 24px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.check-list li {
  position: relative;
  padding-left: 20px;
  font-size: 13px;
  line-height: 1.45;
  color: #333934;
}

.check-list li::before {
  content: "✓";
  position: absolute;
  left: 0;
  top: 0;
  font-family: var(--mono);
  font-size: 10px;
  color: var(--green);
}

.theory-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: var(--rule);
  border: 1px solid var(--rule);
}

.subtask-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  background: var(--rule);
  border: 1px solid var(--rule);
}

.subtask-grid .theory-card {
  scroll-margin-top: 66px;
}

.subtask-grid .method-answer {
  margin-top: 12px;
}

@media (max-width: 820px) {
  .subtask-grid {
    grid-template-columns: 1fr;
  }
}

.theory-card {
  padding: 18px;
  background: var(--surface);
}

.theory-card h3 {
  margin: 0 0 7px;
  font-family: var(--serif);
  font-size: 20px;
  font-weight: 600;
  line-height: 1.15;
  letter-spacing: -0.015em;
}

.theory-card p {
  margin: 0;
  font-size: 13px;
  line-height: 1.5;
  color: var(--muted);
}

.theory-list {
  margin: 10px 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 5px;
}

.theory-list li {
  position: relative;
  padding-left: 14px;
  font-size: 12px;
  line-height: 1.45;
  color: #333934;
}

.theory-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 8px;
  width: 5px;
  height: 1px;
  background: var(--rule-strong);
}

.formula-inline {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-top: 11px;
}

.formula-inline code {
  display: inline-block;
  padding: 5px 7px;
  background: var(--surface-2);
  border: 1px solid var(--rule);
  font-family: var(--mono);
  font-size: 10px;
  line-height: 1.3;
  color: var(--ink);
}

.theory-example {
  margin-top: 22px;
  padding: 20px;
  border: 1px solid var(--rule);
  background: var(--surface);
}

.theory-example-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
  gap: 18px;
  align-items: start;
  margin-bottom: 16px;
  min-width: 0;
}

.theory-example-grid > * {
  min-width: 0;
}

.theory-example-grid--single {
  grid-template-columns: minmax(0, 1fr);
}

.graph-wrap {
  min-width: 0;
}

.graph-svg {
  display: block;
  width: 100%;
  height: auto;
  background: var(--surface-2);
  border: 1px solid var(--rule);
}

.graph-edges line {
  stroke: var(--ink);
  stroke-width: 1.2;
}

.graph-edge-labels text {
  font-family: var(--mono);
  font-size: 10px;
  fill: var(--red);
  paint-order: stroke;
  stroke: var(--surface-2);
  stroke-width: 3px;
}

.graph-nodes circle {
  fill: var(--surface);
  stroke: var(--ink);
  stroke-width: 1.5;
}

.graph-nodes text {
  font-family: var(--serif);
  font-size: 14px;
  fill: var(--ink);
  text-anchor: middle;
  dominant-baseline: central;
}

.table-wrap {
  min-width: 0;
  overflow-x: auto;
}

.example-table {
  width: 100%;
  border-collapse: collapse;
  font-family: var(--mono);
  font-size: 10px;
  line-height: 1.3;
  font-variant-numeric: tabular-nums;
}

.example-table caption {
  caption-side: top;
  padding: 0 0 8px;
  font-size: 9px;
  line-height: 1.4;
  text-align: left;
  color: var(--muted);
}

.example-table + .example-table {
  margin-top: 14px;
}

.example-table th,
.example-table td {
  padding: 6px 5px;
  border: 1px solid var(--rule);
  text-align: center;
}

.example-table thead th {
  background: var(--surface-2);
  font-weight: 500;
  color: var(--muted);
}

.example-table tbody th {
  background: var(--surface-2);
  font-weight: 500;
  color: var(--muted);
}

.example-answer {
  display: flex;
  align-items: baseline;
  gap: 10px;
  margin: 16px 0 0;
  padding: 11px 13px;
  border-left: 2px solid var(--green);
  background: var(--green-soft);
  font-size: 13px;
  line-height: 1.45;
  color: #243d2e;
}

.example-answer span,
.method-answer span {
  flex: 0 0 auto;
  font-family: var(--mono);
  font-size: 8px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--green);
}

/* ------------------------------------------------------------ methods */

.methods-list {
  display: grid;
  gap: 14px;
  min-width: 0;
}

.method-card {
  min-width: 0;
  padding: 20px;
  background: var(--surface);
  border: 1px solid var(--rule);
}

.method-head > div {
  min-width: 0;
}

.method-head {
  display: grid;
  grid-template-columns: 52px minmax(0, 1fr);
  gap: 14px;
  align-items: start;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--rule);
}

.method-num {
  font-family: var(--serif);
  font-size: 40px;
  font-weight: 600;
  line-height: 0.8;
  letter-spacing: -0.05em;
  color: var(--red);
}

.method-head .eyebrow {
  margin-bottom: 4px;
  color: var(--red);
}

.method-head h3 {
  margin: 0;
  font-family: var(--serif);
  font-size: clamp(22px, 2.4vw, 28px);
  font-weight: 600;
  line-height: 1.1;
  letter-spacing: -0.02em;
}

.method-when {
  margin: 12px 0 12px;
  font-size: 13px;
  line-height: 1.5;
  color: var(--muted);
}

.method-when strong {
  color: var(--ink);
  font-weight: 600;
}

.method-card .task-steps {
  margin-top: 4px;
}

.method-card .task-list {
  margin-top: 4px;
}

.method-example {
  min-width: 0;
  margin-top: 14px;
  padding: 13px 15px;
  background: var(--surface-2);
  border-left: 2px solid var(--blue);
}

.method-example > p:not(.mini-label):not(.method-answer) {
  margin: 0;
  font-size: 13px;
  line-height: 1.5;
  color: #333934;
}

.code-block {
  max-width: 100%;
  margin: 11px 0 0;
  padding: 12px 14px;
  overflow-x: auto;
  background: var(--ink);
  color: var(--paper);
  font-family: var(--mono);
  font-size: 11px;
  line-height: 1.55;
}

.code-block code {
  font-family: inherit;
  white-space: pre;
}

.method-answer {
  display: flex;
  align-items: baseline;
  gap: 9px;
  margin: 11px 0 0;
  padding-top: 10px;
  border-top: 1px solid var(--rule);
  font-size: 13px;
  line-height: 1.45;
  color: #243d2e;
}

.method-source {
  margin: 12px 0 0;
  padding-top: 10px;
  border-top: 1px solid var(--rule);
  font-family: var(--mono);
  font-size: 8px;
  line-height: 1.5;
  letter-spacing: 0.03em;
  text-transform: uppercase;
  color: var(--muted);
}

/* ---------------------------------------------------------- cheatsheet */

.cheatsheet {
  margin-top: 22px;
}

.cheatsheet-wrap {
  overflow-x: auto;
  border: 1px solid var(--rule);
}

.cheatsheet-table {
  width: 100%;
  border-collapse: collapse;
  min-width: 520px;
  font-size: 12px;
  line-height: 1.4;
}

.cheatsheet-table th {
  padding: 8px 12px;
  background: var(--surface-2);
  border-bottom: 1px solid var(--ink);
  font-family: var(--mono);
  font-size: 8px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  text-align: left;
  color: var(--muted);
}

.cheatsheet-table td {
  padding: 9px 12px;
  border-bottom: 1px solid var(--rule);
  vertical-align: top;
}

.cheatsheet-table tr:last-child td {
  border-bottom: 0;
}

.cheatsheet-table td:first-child {
  color: var(--ink);
  width: 52%;
}

.cheatsheet-table td:last-child {
  color: var(--muted);
}

/* -------------------------------------------------- video solutions */

.video-solutions {
  display: grid;
  gap: 14px;
  margin-top: 22px;
}

.solution-head {
  grid-template-columns: 92px minmax(0, 1fr);
}

.solution-num {
  padding-top: 7px;
  font-family: var(--mono);
  font-size: 13px;
  font-weight: 600;
  line-height: 1.2;
  letter-spacing: 0.02em;
  color: var(--blue);
}

.solution-condition {
  margin: 12px 0 0;
  font-size: 13px;
  line-height: 1.55;
  color: #333934;
}

.solution-link {
  margin: 12px 0 0;
  font-size: 13px;
  line-height: 1.4;
}

.solution-link a {
  color: var(--blue);
  text-decoration: underline;
  text-underline-offset: 3px;
}

@media (max-width: 640px) {
  .solution-head {
    grid-template-columns: 1fr;
    gap: 6px;
  }
}

/* ------------------------------------------------------ video archive */

.archive-block {
  margin-top: 18px;
  border: 1px solid var(--rule);
  background: var(--surface);
}

.archive-block > summary {
  padding: 14px 16px;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  color: var(--ink);
}

.archive-list {
  display: grid;
  gap: 8px;
  padding: 0 12px 12px;
}

.archive-item {
  border: 1px solid var(--rule);
  background: var(--surface-2);
}

.archive-item > summary {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 10px;
  align-items: baseline;
  padding: 9px 12px;
  cursor: pointer;
}

.archive-time {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--blue);
  white-space: nowrap;
}

.archive-title {
  font-size: 13px;
  line-height: 1.35;
  color: var(--ink);
}

.archive-num {
  margin-left: auto;
  font-family: var(--mono);
  font-size: 11px;
  color: var(--red);
  white-space: nowrap;
}

.archive-body {
  padding: 10px 12px 12px;
  border-top: 1px solid var(--rule);
}

.archive-condition {
  margin: 0 0 8px;
  font-size: 12px;
  line-height: 1.5;
  color: #333934;
  white-space: pre-line;
}

.archive-empty {
  margin: 0;
  font-size: 12px;
  color: var(--muted);
}

/* --------------------------------------------------------------- video */

.video-block {
  margin-top: 22px;
  padding: 16px;
  border: 1px solid var(--rule);
  background: var(--surface-2);
}

.video-list {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: var(--rule);
  border: 1px solid var(--rule);
}

.video-link {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 11px 66px 11px 13px;
  background: var(--surface);
  color: var(--ink);
  text-decoration: none;
}

.video-link:hover {
  background: var(--paper);
}

.video-label {
  font-family: var(--serif);
  font-size: 16px;
  font-weight: 600;
  line-height: 1.2;
}

.video-meta {
  font-family: var(--mono);
  font-size: 8px;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--muted);
}

.video-host {
  position: absolute;
  top: 50%;
  right: 8px;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 3px;
  width: 52px;
  transform: translateY(-50%);
}

.video-host-icon {
  display: block;
  width: 22px;
  height: 22px;
  border-radius: 5px;
  overflow: hidden;
}

.video-host-icon svg {
  display: block;
  width: 100%;
  height: 100%;
}

.video-host-name {
  font-family: var(--mono);
  font-size: 8px;
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--muted);
  white-space: nowrap;
}

.video-note {
  margin: 9px 0 0;
  font-size: 10px;
  color: var(--muted);
}

.method-source-note {
  margin: 18px 0 0;
  padding-top: 12px;
  border-top: 1px solid var(--rule);
  font-size: 11px;
  line-height: 1.5;
  color: var(--muted);
}

/* ---------------------------------------------------------- responsive */

@media (max-width: 920px) {
  .theory-grid {
    grid-template-columns: 1fr;
  }

  .theory-example-grid {
    grid-template-columns: 1fr;
  }

  .check-list {
    grid-template-columns: 1fr;
  }

  .video-list {
    grid-template-columns: 1fr;
  }

  .task-toc {
    gap: 14px;
  }
}

@media (max-width: 640px) {
  .task-toc {
    margin-left: -14px;
    margin-right: -14px;
    padding-left: 14px;
    padding-right: 14px;
  }

  .task-toc-label {
    display: none;
  }

  .theory-checklist {
    padding: 13px;
  }

  .theory-example {
    padding: 14px;
  }

  .method-card {
    padding: 15px;
  }

  .method-head {
    grid-template-columns: 40px minmax(0, 1fr);
    gap: 10px;
  }

  .method-num {
    font-size: 32px;
  }

  .example-table {
    font-size: 9px;
  }

  .example-table th,
  .example-table td {
    padding: 5px 3px;
  }

  .code-block {
    font-size: 10px;
  }

  .code-block code {
    white-space: pre-wrap;
    overflow-wrap: anywhere;
  }
}

/* --------------------------------------------------------- video report */

.report-hero {
  padding: 30px 0 20px;
  border-bottom: 1px solid var(--rule);
}

.report-hero h1 {
  margin: 8px 0 10px;
  font-family: var(--serif);
  font-size: clamp(34px, 5vw, 62px);
  font-weight: 600;
  line-height: 0.98;
  letter-spacing: -0.04em;
}

.report-stats {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 18px;
}

.report-stats > div {
  display: flex;
  align-items: baseline;
  gap: 7px;
  padding: 8px 12px;
  border: 1px solid var(--rule);
  background: var(--surface);
}

.report-stats strong {
  font-family: var(--serif);
  font-size: 24px;
  line-height: 1;
}

.report-stats span {
  font-size: 11px;
  color: var(--muted);
}

.report-toolbar {
  position: sticky;
  top: 0;
  z-index: 10;
  margin: 0 -30px;
  padding: 16px 30px 14px;
  background: var(--surface);
  border-bottom: 1px solid var(--rule);
}

.report-search-row {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  align-items: flex-end;
}

.report-search-row .search-label {
  width: 100%;
  margin-bottom: -4px;
}

#video-search {
  flex: 1 1 260px;
  min-width: 0;
  border: 1px solid var(--rule-strong);
  background: var(--paper);
  color: var(--ink);
  padding: 10px 12px;
  font-size: 14px;
}

#video-search:focus {
  border-color: var(--ink);
  outline: 0;
  box-shadow: inset 0 0 0 1px var(--ink);
}

.report-filter-grid {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 14px;
  align-items: end;
  margin-top: 12px;
}

.report-filter-grid > label {
  display: grid;
  gap: 5px;
  font-family: var(--mono);
  font-size: 9px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
}

.report-filter-grid select {
  min-width: 160px;
  border: 1px solid var(--rule-strong);
  background: var(--paper);
  color: var(--ink);
  padding: 8px 10px;
  font-family: var(--sans);
  font-size: 12px;
}

.report-check {
  display: flex !important;
  grid-auto-flow: column;
  align-items: center;
  gap: 6px;
  padding-bottom: 1px;
  font-family: var(--sans) !important;
  font-size: 12px !important;
  letter-spacing: 0 !important;
  text-transform: none !important;
  color: var(--ink) !important;
}

.report-count {
  margin: 10px 0 0;
  font-family: var(--mono);
  font-size: 10px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.report-table-wrap {
  overflow-x: auto;
  margin: 18px 0 40px;
  border: 1px solid var(--rule);
  background: var(--surface);
}

.report-table {
  width: 100%;
  min-width: 980px;
  border-collapse: collapse;
  font-size: 12px;
}

.report-table th {
  position: sticky;
  top: 0;
  z-index: 2;
  padding: 10px 12px;
  text-align: left;
  font-family: var(--mono);
  font-size: 9px;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
  background: var(--surface-2);
  border-bottom: 1px solid var(--rule-strong);
}

.report-table td {
  padding: 10px 12px;
  vertical-align: top;
  border-bottom: 1px solid var(--rule);
}

.report-row:hover td {
  background: var(--paper);
}

.report-task-link {
  display: grid;
  gap: 3px;
  color: var(--ink);
  text-decoration: none;
}

.report-task-num {
  font-family: var(--serif);
  font-size: 22px;
  font-weight: 600;
  line-height: 1;
  color: var(--red);
}

.report-task-title {
  font-size: 11px;
  line-height: 1.3;
  color: var(--muted);
}

.report-fragment {
  display: grid;
  gap: 4px;
  min-width: 190px;
}

.report-year {
  font-family: var(--mono);
  font-size: 10px;
  color: var(--blue);
}

.report-fragment-title {
  font-size: 12px;
  line-height: 1.35;
  color: var(--ink);
}

.report-video-link {
  font-size: 10px;
  color: var(--blue);
  text-decoration: underline;
  text-underline-offset: 2px;
}

.report-details summary {
  cursor: pointer;
  font-size: 11px;
  color: var(--blue);
}

.report-condition {
  max-width: 440px;
  margin: 8px 0 0;
  font-size: 11px;
  line-height: 1.5;
  color: #333934;
  white-space: pre-line;
}

.report-details .code-block {
  max-width: 520px;
  font-size: 10px;
}

.report-answer {
  font-family: var(--mono);
  font-size: 11px;
  color: var(--ink);
  white-space: pre-line;
}

.report-empty {
  color: #a6aaa2;
}

.report-empty-state {
  padding: 30px 0;
  text-align: center;
  color: var(--muted);
}

@media (max-width: 640px) {
  .report-toolbar {
    margin: 0 -16px;
    padding: 14px 16px;
  }

  .report-filter-grid select {
    min-width: 140px;
  }
}


/* ---------------------------------------------------------- video editor */

.editor-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 18px 0 0;
}

.editor-import {
  display: inline-flex;
  align-items: center;
  cursor: pointer;
}

.editor-list {
  display: grid;
  gap: 10px;
  margin: 18px 0 40px;
}

.editor-item {
  padding: 14px 16px;
  border: 1px solid var(--rule);
  background: var(--surface);
}

.editor-item-head {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 14px;
  align-items: baseline;
  margin-bottom: 6px;
}

.editor-item-task {
  font-family: var(--mono);
  font-size: 10px;
  color: var(--red);
}

.editor-item-time {
  font-family: var(--mono);
  font-size: 10px;
  color: var(--blue);
}

.editor-item h3 {
  margin: 0 0 6px;
  font-family: var(--serif);
  font-size: 20px;
  font-weight: 600;
  line-height: 1.2;
}

.editor-item-condition {
  margin: 0 0 8px;
  font-size: 12px;
  line-height: 1.45;
  color: #333934;
}

.editor-item-meta {
  margin: 0 0 10px;
  font-size: 10px;
  color: var(--muted);
}

.editor-dialog {
  width: min(760px, calc(100vw - 30px));
  max-height: 92vh;
  padding: 0;
  border: 1px solid var(--rule-strong);
  background: var(--surface);
  color: var(--ink);
}

.editor-dialog::backdrop {
  background: rgba(20, 24, 20, 0.45);
}

.editor-dialog form {
  padding: 18px;
}

.editor-dialog-head {
  display: flex;
  justify-content: space-between;
  align-items: start;
  gap: 10px;
  margin-bottom: 14px;
}

.editor-close {
  border: 0;
  background: transparent;
  font-size: 26px;
  line-height: 1;
  cursor: pointer;
  color: var(--muted);
}

.editor-form-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px 12px;
}

.editor-form-grid label {
  display: grid;
  gap: 5px;
  font-family: var(--mono);
  font-size: 9px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
}

.editor-form-grid input,
.editor-form-grid select,
.editor-form-grid textarea {
  width: 100%;
  border: 1px solid var(--rule-strong);
  background: var(--paper);
  color: var(--ink);
  padding: 8px 10px;
  font-family: var(--sans);
  font-size: 12px;
}

.editor-form-grid textarea {
  resize: vertical;
}

.editor-wide {
  grid-column: 1 / -1;
}

.editor-error {
  margin: 12px 0 0;
  font-size: 12px;
  color: var(--red);
}

.editor-dialog-actions {
  display: grid;
  grid-template-columns: auto 1fr auto auto;
  gap: 8px;
  align-items: center;
  margin-top: 16px;
}

@media (max-width: 640px) {
  .editor-form-grid {
    grid-template-columns: 1fr;
  }

  .editor-dialog-actions {
    grid-template-columns: 1fr 1fr;
  }
}