/* ==========================================================================
   必博主页 · 共享站点样式 /assets/site.css
   展览画册式非对称网格 · 深海蓝底 · 荧光青 / 珊瑚橙 / 电光紫强调
   ========================================================================== */

/* ---------- 1. Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body, h1, h2, h3, h4, h5, p, figure, blockquote, dl, dd, ul, ol, pre { margin: 0; }
ul, ol { padding: 0; list-style: none; }
img, svg, video { display: block; max-width: 100%; }
button, input, select, textarea { font: inherit; color: inherit; }
button { background: none; border: 0; padding: 0; cursor: pointer; }
a { color: inherit; text-decoration: none; }
table { border-collapse: collapse; width: 100%; }
[hidden] { display: none !important; }

/* ---------- 2. Tokens ---------- */
:root {
  --deep: #071A2F;
  --navy: #0E2A47;
  --mid: #123E63;
  --mist: #E8F1F7;
  --paper: #F7FAFC;
  --cyan: #2FE0D0;
  --coral: #FF7A59;
  --violet: #7B6BFF;
  --steel: #9FB3C8;
  --haze: #CFF6F1;
  --amber: #FFC24B;
  --ink: #071A2F;
  --ink-soft: #43596E;
  --line: rgba(159, 179, 200, 0.22);
  --line-strong: rgba(159, 179, 200, 0.46);
  --line-ink: rgba(7, 26, 47, 0.16);
  --shadow: 0 4px 8px rgba(3, 12, 24, 0.32);
  --font-sans: "Noto Sans SC", "Source Han Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-mono: "JetBrains Mono", "Roboto Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --fs-body: 17px;
  --lh-body: 1.85;
  --fs-mono: 12px;
  --fs-h1: clamp(34px, 5.2vw, 58px);
  --fs-h2: clamp(26px, 3.6vw, 40px);
  --fs-h3: clamp(20px, 2.2vw, 24px);
  --fs-lede: clamp(18px, 1.9vw, 22px);
  --fs-display: clamp(46px, 8.4vw, 72px);
  --maxw: 1260px;
  --gutter: clamp(20px, 5vw, 64px);
  --radius: 2px;
  --dur: 150ms;
}

/* ---------- 3. Base ---------- */
body {
  background: var(--deep);
  color: var(--mist);
  font-family: var(--font-sans);
  font-size: var(--fs-body);
  line-height: var(--lh-body);
  font-weight: 400;
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}
::selection { background: rgba(47, 224, 208, 0.3); color: var(--paper); }
:focus-visible { outline: 2px solid var(--cyan); outline-offset: 3px; border-radius: 1px; }
a:focus:not(:focus-visible), button:focus:not(:focus-visible) { outline: none; }

h1, h2, h3, h4 { font-weight: 900; line-height: 1.16; letter-spacing: -0.012em; }
h1 { font-size: var(--fs-h1); }
h2 { font-size: var(--fs-h2); }
h3 { font-size: var(--fs-h3); font-weight: 700; }
h4 { font-size: 18px; font-weight: 700; }
#main-content { display: block; scroll-margin-top: 120px; }

/* ---------- 4. Typography helpers ---------- */
.display { font-size: var(--fs-display); font-weight: 900; line-height: 1.04; letter-spacing: -0.02em; }
.lede { font-size: var(--fs-lede); line-height: 1.72; font-weight: 500; }
.mono { font-family: var(--font-mono); font-size: var(--fs-mono); letter-spacing: 0.1em; font-variant-numeric: tabular-nums; }
.eyebrow { font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.24em; text-transform: uppercase; color: var(--steel); }
.prose { max-width: 38em; }
.prose p + p { margin-top: 1.1em; }
.prose strong { font-weight: 700; color: var(--paper); }
.prose a { border-bottom: 1px solid var(--line-strong); transition: border-color var(--dur) ease, color var(--dur) ease; }
.prose a:hover { border-color: var(--cyan); color: var(--cyan); }
.text-cyan { color: var(--cyan); }
.text-coral { color: var(--coral); }
.text-violet { color: var(--violet); }
.text-steel { color: var(--steel); }

/* ---------- 5. Layout ---------- */
.shell { width: min(100% - (2 * var(--gutter)), var(--maxw)); margin-inline: auto; }
.shell--narrow { max-width: 900px; }
.grid-12 { display: grid; grid-template-columns: repeat(12, minmax(0, 1fr)); gap: clamp(16px, 2.4vw, 32px); }
.col-aside { grid-column: 1 / span 3; }
.col-main { grid-column: 5 / span 7; }
.col-side { grid-column: 10 / span 3; }
.col-full { grid-column: 1 / -1; }
.stack-sm { display: grid; gap: 10px; }
.stack-md { display: grid; gap: 20px; }
.stack-lg { display: grid; gap: clamp(32px, 5vw, 72px); }
.cluster { display: flex; flex-wrap: wrap; align-items: center; gap: 12px; }
.mt-lg { margin-top: clamp(28px, 4vw, 56px); }
.visually-hidden {
  position: absolute !important; width: 1px; height: 1px; margin: -1px;
  padding: 0; overflow: hidden; clip: rect(0 0 0 0); white-space: nowrap; border: 0;
}

/* ---------- 6. Zones ---------- */
.zone { padding-block: clamp(56px, 8vw, 136px); }
.zone--deep { background: var(--deep); color: var(--mist); }
.zone--navy { background: var(--navy); color: var(--mist); }
.zone--light { background: var(--paper); color: var(--ink); }
.zone--mist { background: var(--mist); color: var(--ink); }
.zone--grid {
  background-image:
    linear-gradient(rgba(159, 179, 200, 0.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(159, 179, 200, 0.05) 1px, transparent 1px);
  background-size: 56px 56px;
}
.zone--edge { border-top: 1px solid var(--line); }
.section { padding-block: clamp(52px, 7vw, 120px); }
.section__head { display: grid; gap: 14px; margin-bottom: clamp(28px, 4vw, 56px); }
.section__index { font-family: var(--font-mono); font-size: 13px; letter-spacing: 0.22em; color: var(--violet); }
.section__title { font-size: var(--fs-h2); font-weight: 900; }
.section__note { font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.08em; color: var(--steel); }
.hairline { height: 1px; background: var(--line); border: 0; margin: 0; }
.zone--light .hairline, .zone--mist .hairline { background: var(--line-ink); }
.dot { display: inline-block; width: 6px; height: 6px; border-radius: 50%; background: var(--cyan); flex: none; }

/* ---------- 7. Skip link ---------- */
.skip-link {
  position: fixed; left: 18px; top: -100px; z-index: 200;
  background: var(--cyan); color: var(--deep);
  font-size: 14px; font-weight: 700; letter-spacing: 0.04em;
  padding: 10px 18px; border-radius: var(--radius);
  transition: top 140ms ease;
}
.skip-link:focus { top: 14px; }

/* ---------- 8. Site header / masthead ---------- */
.site-header {
  position: sticky; top: 0; z-index: 80;
  background: rgba(7, 26, 47, 0.95);
  -webkit-backdrop-filter: blur(12px);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--line);
  color: var(--mist);
}
.progress-rail { position: absolute; left: 0; right: 0; top: 0; height: 2px; background: rgba(159, 179, 200, 0.16); }
.progress-bar {
  display: block; height: 100%; width: 0;
  background: linear-gradient(90deg, var(--cyan), var(--violet));
  transition: width 80ms linear;
}
.masthead { position: relative; width: min(100% - (2 * var(--gutter)), var(--maxw)); margin-inline: auto; }
.masthead__brand-row {
  display: grid; grid-template-columns: 1fr auto 1fr; align-items: center; gap: 16px;
  padding: clamp(16px, 2.4vw, 28px) 0 clamp(12px, 1.6vw, 18px);
  transition: padding 180ms ease;
}
.brand { display: flex; flex-direction: column; align-items: center; gap: 8px; text-align: center; }
.masthead__brand-row .brand { grid-column: 2; }
.brand__line { display: inline-flex; align-items: center; gap: 12px; }
.brand__mark {
  position: relative; flex: none; width: 14px; height: 14px;
  border: 1px solid var(--cyan);
  background: linear-gradient(135deg, rgba(47, 224, 208, 0.85), rgba(123, 107, 255, 0.18));
  transition: width 180ms ease, height 180ms ease;
}
.brand__mark::after { content: ""; position: absolute; inset: 3px; border: 1px solid rgba(47, 224, 208, 0.45); }
.brand__name {
  font-size: clamp(22px, 3vw, 34px); font-weight: 900; line-height: 1;
  letter-spacing: 0.16em; color: var(--paper); transition: font-size 180ms ease;
}
.brand__sub { font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.26em; color: var(--steel); text-transform: uppercase; }

.nav-toggle {
  grid-column: 3; justify-self: end;
  display: none; align-items: center; gap: 10px;
  padding: 9px 12px; border: 1px solid var(--line-strong); border-radius: var(--radius);
  color: var(--mist); font-size: 13px; letter-spacing: 0.1em;
  transition: border-color var(--dur) ease, color var(--dur) ease;
}
.nav-toggle:hover { border-color: var(--cyan); color: var(--cyan); }
.nav-toggle__bars { display: grid; gap: 4px; width: 18px; }
.nav-toggle__bars span { display: block; height: 1px; background: currentColor; }
.nav-toggle__text { font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.18em; }

.masthead__nav-row { border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.masthead__nav { display: block; }
.nav-list { display: flex; flex-wrap: wrap; justify-content: center; gap: clamp(6px, 1.8vw, 26px); }
.nav-list__item { display: flex; }
.nav-list__link {
  position: relative; display: inline-flex; align-items: center;
  padding: 15px 6px; font-size: 15px; font-weight: 500; letter-spacing: 0.06em;
  color: var(--mist);
  transition: color var(--dur) ease, padding 180ms ease, font-size 180ms ease;
}
.nav-list__link::after {
  content: ""; position: absolute; left: 6px; right: 6px; bottom: 9px; height: 1px;
  background: var(--cyan); transform: scaleX(0); transform-origin: left;
  transition: transform 160ms ease;
}
.nav-list__link:hover { color: var(--cyan); }
.nav-list__link:hover::after { transform: scaleX(1); }
.nav-list__link[aria-current="page"] { color: var(--cyan); }
.nav-list__link[aria-current="page"]::after { transform: scaleX(1); }
.nav-list__link[aria-current="page"]::before {
  content: ""; position: absolute; top: 7px; left: 50%; width: 4px; height: 4px;
  margin-left: -2px; border-radius: 50%; background: var(--coral);
}

.masthead__meta {
  display: flex; align-items: center; justify-content: space-between; gap: 20px;
  max-height: 90px; padding: 11px 0 13px;
  transition: max-height 180ms ease, opacity 160ms ease, padding 180ms ease;
}
.meta-label { font-size: 11px; letter-spacing: 0.18em; text-transform: uppercase; color: var(--steel); }
.masthead__actions { display: flex; flex-wrap: wrap; gap: 8px; }

.action-chip {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 8px 13px; border: 1px solid var(--line-strong); border-radius: var(--radius);
  background: transparent; color: var(--mist);
  font-size: 13px; font-weight: 500; letter-spacing: 0.06em;
  transition: border-color var(--dur) ease, color var(--dur) ease, background-color var(--dur) ease;
}
.action-chip:hover { border-color: var(--cyan); color: var(--cyan); }
.action-chip--accent { border-color: rgba(47, 224, 208, 0.55); color: var(--cyan); }
.action-chip--accent:hover { background: rgba(47, 224, 208, 0.1); }
.action-chip__dot { width: 6px; height: 6px; border-radius: 50%; background: var(--coral); flex: none; }
.action-chip--copy[data-copied="true"] { border-color: var(--cyan); color: var(--cyan); background: rgba(47, 224, 208, 0.1); }

.site-header[data-scrolled="true"] .masthead__brand-row { padding: 10px 0 8px; }
.site-header[data-scrolled="true"] .brand__name { font-size: clamp(17px, 1.6vw, 20px); }
.site-header[data-scrolled="true"] .brand__mark { width: 11px; height: 11px; }
.site-header[data-scrolled="true"] .brand__sub { display: none; }
.site-header[data-scrolled="true"] .masthead__meta { max-height: 0; padding: 0; opacity: 0; overflow: hidden; visibility: hidden; }
.site-header[data-scrolled="true"] .nav-list__link { padding: 11px 6px; font-size: 14px; }

/* ---------- 9. Site footer ---------- */
.site-footer {
  background-color: var(--deep);
  background-image:
    linear-gradient(rgba(159, 179, 200, 0.045) 1px, transparent 1px),
    linear-gradient(90deg, rgba(159, 179, 200, 0.045) 1px, transparent 1px);
  background-size: 64px 64px;
  border-top: 1px solid var(--line);
  color: var(--mist);
  padding-block: clamp(40px, 6vw, 72px) clamp(22px, 3vw, 34px);
}
.footer__inner { width: min(100% - (2 * var(--gutter)), var(--maxw)); margin-inline: auto; }
.footer__top {
  display: flex; flex-wrap: wrap; align-items: flex-end; justify-content: space-between;
  gap: 18px; padding-bottom: clamp(20px, 2.6vw, 30px); border-bottom: 1px solid var(--line);
}
.footer__brand { display: flex; flex-direction: column; gap: 12px; align-items: flex-start; }
.brand--compact .brand__line { gap: 10px; }
.brand--compact .brand__name { font-size: 20px; letter-spacing: 0.14em; }
.brand--compact .brand__sub { font-size: 10px; letter-spacing: 0.22em; }
.footer__note { max-width: 30em; font-size: 14px; line-height: 1.75; color: var(--steel); }
.footer__grid {
  display: grid; grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(18px, 3vw, 44px);
  padding: clamp(26px, 3.4vw, 42px) 0;
  border-bottom: 1px solid var(--line);
}
.footer__col { display: grid; align-content: start; }
.footer__col-title {
  margin-bottom: 14px; font-family: var(--font-mono); font-size: 11px; font-weight: 500;
  letter-spacing: 0.24em; text-transform: uppercase; color: var(--cyan);
}
.footer__list { display: grid; gap: 2px; }
.footer__link {
  display: flex; align-items: baseline; justify-content: space-between; gap: 12px;
  padding: 9px 0; font-size: 15px; color: var(--mist);
  transition: color var(--dur) ease;
}
.footer__link::after {
  content: attr(data-updated);
  font-family: var(--font-mono); font-size: 10px; letter-spacing: 0.08em;
  color: var(--steel); white-space: nowrap;
  opacity: 0; transform: translateX(-6px);
  transition: opacity var(--dur) ease, transform var(--dur) ease, color var(--dur) ease;
}
.footer__link:hover, .footer__link:focus-visible { color: var(--cyan); }
.footer__link:hover::after, .footer__link:focus-visible::after { opacity: 1; transform: none; color: var(--cyan); }
.footer__base {
  display: flex; flex-wrap: wrap; align-items: center; justify-content: space-between;
  gap: 14px; padding: clamp(18px, 2.4vw, 24px) 0;
}
.footer__contact { font-size: 12px; letter-spacing: 0.06em; line-height: 1.9; color: var(--steel); }
.copy-btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 9px 14px; border: 1px solid var(--line-strong); border-radius: var(--radius);
  font-size: 13px; letter-spacing: 0.06em; color: var(--mist);
  transition: border-color var(--dur) ease, color var(--dur) ease, background-color var(--dur) ease;
}
.copy-btn:hover { border-color: var(--cyan); color: var(--cyan); }
.copy-btn[data-copied="true"] { border-color: var(--cyan); color: var(--cyan); background: rgba(47, 224, 208, 0.1); }
.footer__legal {
  display: flex; flex-wrap: wrap; align-items: center; gap: 10px 22px;
  padding-top: 18px; border-top: 1px solid var(--line);
  font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.1em; color: var(--steel);
}
.footer__legal-item { display: inline-flex; align-items: center; gap: 8px; }

/* ---------- 10. Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 10px;
  padding: 13px 22px; border: 1px solid var(--line-strong); border-radius: var(--radius);
  font-size: 15px; font-weight: 500; letter-spacing: 0.05em; color: var(--mist);
  transition: border-color var(--dur) ease, color var(--dur) ease, background-color var(--dur) ease;
}
.btn:hover { border-color: var(--cyan); color: var(--cyan); background: rgba(47, 224, 208, 0.08); }
.btn--primary { background: var(--cyan); border-color: var(--cyan); color: var(--deep); font-weight: 700; }
.btn--primary:hover { background: transparent; color: var(--cyan); }
.btn--ghost { padding: 6px 0; border: 0; border-bottom: 1px solid var(--line-strong); border-radius: 0; }
.btn--ghost:hover { background: none; border-bottom-color: var(--cyan); }
.zone--light .btn, .zone--mist .btn { color: var(--ink); border-color: var(--line-ink); }
.zone--light .btn:hover, .zone--mist .btn:hover { color: var(--mid); border-color: var(--mid); background: rgba(18, 62, 99, 0.06); }

/* ---------- 11. Chips / status ---------- */
.chip {
  display: inline-flex; align-items: center; gap: 6px;
  padding: 4px 10px; border: 1px solid var(--line); border-radius: 999px;
  font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.1em;
  color: var(--steel); white-space: nowrap;
}
.chip--cyan { color: var(--cyan); border-color: rgba(47, 224, 208, 0.42); }
.chip--coral { color: var(--coral); border-color: rgba(255, 122, 89, 0.42); }
.chip--violet { color: var(--violet); border-color: rgba(123, 107, 255, 0.48); }
.chip--amber { color: var(--amber); border-color: rgba(255, 196, 75, 0.42); }
.zone--light .chip, .zone--mist .chip { color: var(--mid); border-color: var(--line-ink); }
.zone--light .chip--cyan, .zone--mist .chip--cyan { color: #0C8C82; border-color: rgba(12, 140, 130, 0.35); }

.status { display: inline-flex; align-items: center; gap: 8px; font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.12em; color: var(--steel); }
.status__dot { width: 7px; height: 7px; border-radius: 50%; background: var(--steel); flex: none; }
.status--live { color: var(--cyan); }
.status--live .status__dot { background: var(--cyan); box-shadow: 0 0 0 3px rgba(47, 224, 208, 0.16); }
.status--gray { color: var(--amber); }
.status--gray .status__dot { background: var(--amber); }
.status--planned { color: var(--violet); }
.status--planned .status__dot { background: transparent; border: 1px solid var(--violet); }

/* ---------- 12. Index rows ---------- */
.index-list { display: grid; }
.index-row {
  display: grid; grid-template-columns: auto minmax(0, 1fr) auto;
  gap: clamp(12px, 2vw, 28px); align-items: baseline;
  padding: 18px 4px; border-top: 1px solid var(--line);
  transition: background-color var(--dur) ease, border-color var(--dur) ease;
}
.index-row:last-child { border-bottom: 1px solid var(--line); }
.index-row:hover { border-color: var(--cyan); background: rgba(47, 224, 208, 0.04); }
.index-row__no { font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.12em; color: var(--violet); }
.index-row__title { font-size: 17px; font-weight: 500; color: var(--paper); }
.index-row__meta { font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.1em; color: var(--steel); }
.zone--light .index-row, .zone--mist .index-row { border-color: var(--line-ink); }
.zone--light .index-row__title, .zone--mist .index-row__title { color: var(--ink); }
.zone--light .index-row:hover, .zone--mist .index-row:hover { background: rgba(18, 62, 99, 0.05); border-color: var(--mid); }

/* ---------- 13. Filters ---------- */
.filter-bar { display: flex; flex-wrap: wrap; gap: 10px; padding-bottom: 16px; border-bottom: 1px solid var(--line); }
.filter-chip {
  padding: 7px 14px; border: 1px solid var(--line); border-radius: 999px;
  font-size: 13px; letter-spacing: 0.04em; color: var(--mist);
  transition: border-color var(--dur) ease, color var(--dur) ease, background-color var(--dur) ease;
}
.filter-chip:hover { border-color: var(--cyan); color: var(--cyan); }
.filter-chip[aria-pressed="true"] { border-color: var(--cyan); background: rgba(47, 224, 208, 0.12); color: var(--cyan); }
.filter-count { padding-top: 12px; font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.14em; color: var(--steel); }
.zone--light .filter-bar, .zone--mist .filter-bar { border-color: var(--line-ink); }
.zone--light .filter-chip, .zone--mist .filter-chip { color: var(--ink); border-color: var(--line-ink); }
.zone--light .filter-chip[aria-pressed="true"], .zone--mist .filter-chip[aria-pressed="true"] { color: #0C8C82; border-color: #0C8C82; background: rgba(12, 140, 130, 0.1); }

/* ---------- 14. Side index ---------- */
.side-index { position: sticky; top: 128px; align-self: start; display: grid; gap: 14px; }
.side-index__title { font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.22em; text-transform: uppercase; color: var(--steel); }
.side-index__list { display: grid; gap: 2px; border-left: 1px solid var(--line); }
.side-index__link {
  display: block; margin-left: -1px; padding: 7px 0 7px 14px;
  font-size: 14px; color: var(--steel); border-left: 1px solid transparent;
  transition: color var(--dur) ease, border-color var(--dur) ease;
}
.side-index__link:hover { color: var(--cyan); }
.side-index__link[aria-current="true"] { color: var(--cyan); border-left-color: var(--cyan); }
.side-index__progress { font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.12em; color: var(--steel); }

/* ---------- 15. Figures ---------- */
.figure { display: grid; gap: 10px; margin: 0; }
.figure__frame {
  position: relative; overflow: hidden; aspect-ratio: 16 / 9;
  border: 1px solid var(--line); border-radius: var(--radius);
  background: linear-gradient(150deg, rgba(18, 62, 99, 0.85), rgba(7, 26, 47, 0.96));
  box-shadow: var(--shadow);
}
.figure__frame::before {
  content: ""; position: absolute; inset: 0; opacity: 0.8;
  background-image:
    linear-gradient(rgba(159, 179, 200, 0.09) 1px, transparent 1px),
    linear-gradient(90deg, rgba(159, 179, 200, 0.09) 1px, transparent 1px);
  background-size: 32px 32px;
}
.figure__frame::after {
  content: ""; position: absolute; inset: 0;
  background: radial-gradient(120% 90% at 12% 8%, rgba(47, 224, 208, 0.18), transparent 58%);
}
.figure__frame > img, .figure__frame > svg, .figure__frame > video {
  position: relative; z-index: 1; width: 100%; height: 100%; object-fit: cover;
}
.figure__caption { font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.08em; color: var(--steel); }
.figure--wide .figure__frame { aspect-ratio: 21 / 9; }
.figure--tall .figure__frame { aspect-ratio: 3 / 4; }
.figure--square .figure__frame { aspect-ratio: 1 / 1; }
.figure--device .figure__frame { aspect-ratio: 9 / 19; max-width: 300px; }
.figure--ghost .figure__frame { background: transparent; box-shadow: none; border-style: dashed; }

/* ---------- 16. Timeline ---------- */
.timeline { position: relative; display: grid; gap: 28px; padding-left: 26px; border-left: 1px solid var(--line); }
.timeline__item { position: relative; display: grid; gap: 8px; }
.timeline__node {
  position: absolute; left: -31px; top: 7px; width: 9px; height: 9px; border-radius: 50%;
  background: var(--cyan); box-shadow: 0 0 0 4px rgba(47, 224, 208, 0.14);
}
.timeline__date { font-family: var(--font-mono); font-size: 11px; letter-spacing: 0.14em; color: var(--coral); }

/* ---------- 17. Breadcrumbs ---------- */
.crumbs { display: flex; flex-wrap: wrap; align-items: center; gap: 10px; font-family: var(--font-mono); font-size: 12px; letter-spacing: 0.08em; color: var(--steel); }
.crumbs__link { padding-bottom: 2px; border-bottom: 1px solid transparent; transition: color var(--dur) ease, border-color var(--dur) ease; }
.crumbs__link:hover { color: var(--cyan); border-bottom-color: var(--cyan); }
.crumbs__sep { color: rgba(159, 179, 200, 0.5); }
.crumbs__current { color: var(--mist); }
.zone--light .crumbs__current, .zone--mist .crumbs__current { color: var(--ink); }
.zone--light .crumbs__link, .zone--mist .crumbs__link { color: var(--ink-soft); }

/* ---------- 18. Responsive ---------- */
@media (max-width: 1024px) {
  .col-aside { grid-column: 1 / span 4; }
  .col-main { grid-column: 5 / span 8; }
  .col-side { grid-column: 5 / span 8; }
  .side-index { position: static; }
}
@media (max-width: 900px) {
  .nav-toggle { display: inline-flex; }
  .masthead__brand-row { grid-template-columns: 1fr auto; gap: 12px; padding: 14px 0; }
  .masthead__brand-row .brand { grid-column: 1; flex-direction: row; align-items: center; gap: 10px; text-align: left; }
  .brand__sub { display: none; }
  .masthead__nav-row { border-bottom: 0; }
  .masthead__nav {
    position: absolute; left: calc(-1 * var(--gutter)); right: calc(-1 * var(--gutter)); top: 100%;
    background: var(--deep); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line);
    max-height: 0; opacity: 0; visibility: hidden; overflow: hidden;
    transition: max-height 240ms ease, opacity 180ms ease, visibility 180ms ease;
  }
  .masthead__nav[data-open="true"] { max-height: min(72vh, 520px); opacity: 1; visibility: visible; overflow-y: auto; }
  .nav-list { flex-direction: column; gap: 0; padding: 8px 0; }
  .nav-list__item { border-bottom: 1px solid var(--line); }
  .nav-list__link { width: 100%; padding: 16px 4px; font-size: 16px; }
  .nav-list__link::after { display: none; }
  .nav-list__link[aria-current="page"]::before { left: auto; right: 2px; top: 50%; margin-top: -2px; }
  .masthead__meta { display: none; }
  .grid-12 { grid-template-columns: repeat(6, minmax(0, 1fr)); }
  .col-aside, .col-main, .col-side, .col-full { grid-column: 1 / -1; }
  .footer__grid { grid-template-columns: 1fr; gap: 26px; }
  .footer__top { align-items: flex-start; }
}
@media (max-width: 600px) {
  :root { --fs-body: 16px; }
  .index-row { grid-template-columns: auto minmax(0, 1fr); row-gap: 6px; }
  .index-row__meta { grid-column: 2; }
  .footer__base { flex-direction: column; align-items: flex-start; }
}

/* ---------- 19. Reduced motion ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
}