/* =========================================================
   乐竞体育站 · /assets/site.css
   夜间赛场指挥台：框架式导航 + 纵向刻度 + 编号章节
   ========================================================= */

/* ---------- 1. Reset ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

body,
h1, h2, h3, h4, h5, h6,
p, ul, ol, li, figure, figcaption, blockquote, dl, dd, fieldset {
  margin: 0;
}

ul, ol { padding: 0; list-style: none; }
img, svg, video { display: block; max-width: 100%; height: auto; }
button { font: inherit; color: inherit; background: none; border: 0; padding: 0; cursor: pointer; }
a { color: inherit; text-decoration: none; }
hr { border: 0; height: 0; }
table { border-collapse: collapse; }

:where(a, button, [tabindex], summary, input, select, textarea):focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
  box-shadow: 0 0 0 6px rgba(255, 138, 61, 0.22);
  border-radius: 2px;
}

/* ---------- 2. Tokens ---------- */
:root {
  --ink-950: #061A13;
  --ink-900: #0B2A20;
  --ink-800: #123D2E;
  --ink-700: #1B5A45;
  --cyan: #35F0D0;
  --orange: #FF8A3D;
  --amber: #FFC857;
  --paper: #F2F5EF;
  --muted: #A9C2B6;
  --line: #6F8F82;
  --line-soft: rgba(111, 143, 130, 0.32);
  --line-faint: rgba(111, 143, 130, 0.15);
  --teal: #0E4F6B;
  --brown: #2A1F16;

  --rail-w: 76px;
  --topbar-h: 56px;
  --wrap: 1200px;
  --radius: 3px;

  --font-head: "Archivo Narrow", "Barlow Condensed", "PingFang SC", "Microsoft YaHei", system-ui, sans-serif;
  --font-body: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, "Roboto Mono", Consolas, monospace;

  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
  --shadow-panel: inset 0 1px 0 rgba(242, 245, 239, 0.06), 0 18px 40px -30px rgba(0, 0, 0, 0.95);
  --scroll-progress: 0;
}

/* ---------- 3. Base ---------- */
html { background-color: var(--ink-950); }

body {
  min-height: 100vh;
  padding-left: var(--rail-w);
  padding-top: var(--topbar-h);
  color: var(--paper);
  font-family: var(--font-body);
  font-size: clamp(15px, 0.9vw + 8px, 17px);
  line-height: 1.75;
  background-color: var(--ink-950);
  background-image:
    linear-gradient(to right, var(--line-faint) 1px, transparent 1px),
    linear-gradient(to bottom, var(--line-faint) 1px, transparent 1px);
  background-size: 72px 72px;
  background-attachment: fixed;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

::selection {
  background: rgba(53, 240, 208, 0.24);
  color: var(--paper);
}

/* ---------- 4. Typography ---------- */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-head);
  font-weight: 800;
  line-height: 1.14;
  letter-spacing: -0.012em;
  color: var(--paper);
}

h1 { font-size: clamp(2.4rem, 4.4vw, 4.25rem); }
h2 { font-size: clamp(1.65rem, 2.5vw, 2.4rem); }
h3 { font-size: clamp(1.15rem, 1.4vw, 1.4rem); }
h4 { font-size: 1.05rem; }

p { max-width: 74ch; }
strong { color: var(--paper); font-weight: 650; }

.mono {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.02em;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.65em;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.26em;
  text-transform: uppercase;
  color: var(--cyan);
}

.eyebrow::before {
  content: "";
  width: 18px;
  height: 1px;
  background: currentColor;
  opacity: 0.7;
}

.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  margin: -1px; padding: 0;
  overflow: hidden;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  white-space: nowrap;
}

/* ---------- 5. Layout ---------- */
.wrap {
  width: 100%;
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: clamp(20px, 3.4vw, 48px);
}

.section { padding-block: clamp(56px, 7vw, 104px); }
.section--tight { padding-block: clamp(32px, 4vw, 56px); }

.grid {
  display: grid;
  gap: clamp(16px, 2vw, 28px);
}
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }

.split {
  display: grid;
  gap: clamp(20px, 3vw, 44px);
  grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
}
.split--rev { grid-template-columns: minmax(0, 7fr) minmax(0, 5fr); }

.rule {
  width: 100%;
  height: 1px;
  background: var(--line-soft);
  border: 0;
}

/* ---------- 6. Components ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 0.55em;
  padding: 10px 18px;
  border: 1px solid transparent;
  border-radius: 2px;
  font-family: var(--font-body);
  font-size: 13px;
  font-weight: 650;
  line-height: 1.4;
  letter-spacing: 0.08em;
  white-space: nowrap;
  transition: background 0.18s var(--ease), border-color 0.18s var(--ease),
              color 0.18s var(--ease), box-shadow 0.18s var(--ease), transform 0.18s var(--ease);
}

.btn--accent {
  background: var(--orange);
  border-color: var(--orange);
  color: #20120A;
  box-shadow: 0 8px 22px -16px rgba(255, 138, 61, 0.9);
}
.btn--accent:hover {
  background: #FFA163;
  border-color: #FFA163;
  box-shadow: 0 0 0 3px rgba(255, 138, 61, 0.18);
}

.btn--ghost {
  background: rgba(18, 61, 46, 0.45);
  border-color: var(--line-soft);
  color: var(--paper);
}
.btn--ghost:hover {
  border-color: var(--cyan);
  color: var(--cyan);
  background: rgba(53, 240, 208, 0.08);
}

.btn--quiet {
  padding-inline: 2px;
  color: var(--muted);
  letter-spacing: 0.06em;
}
.btn--quiet:hover { color: var(--cyan); }

.tag {
  display: inline-flex;
  align-items: center;
  gap: 0.5em;
  padding: 3px 10px;
  border: 1px solid var(--line-soft);
  border-radius: 99px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  line-height: 1.7;
  color: var(--muted);
}
.tag::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: currentColor;
  flex: none;
}
.tag--live { color: var(--orange); border-color: rgba(255, 138, 61, 0.45); background: rgba(255, 138, 61, 0.08); }
.tag--done { color: var(--cyan); border-color: rgba(53, 240, 208, 0.4); background: rgba(53, 240, 208, 0.07); }
.tag--pending { color: var(--amber); border-color: rgba(255, 200, 87, 0.4); background: rgba(255, 200, 87, 0.07); }
.tag--saved { color: var(--paper); border-color: var(--line-soft); background: rgba(242, 245, 239, 0.05); }

.panel {
  position: relative;
  padding: clamp(18px, 2vw, 26px);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  background:
    linear-gradient(180deg, rgba(18, 61, 46, 0.55), rgba(11, 42, 32, 0.55));
  box-shadow: var(--shadow-panel);
  transition: border-color 0.18s var(--ease), background 0.18s var(--ease), transform 0.18s var(--ease);
}
.panel:hover {
  border-color: rgba(53, 240, 208, 0.45);
  background: linear-gradient(180deg, rgba(27, 90, 69, 0.5), rgba(11, 42, 32, 0.62));
  transform: translateY(-2px);
}

.chapter {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: end;
  gap: clamp(14px, 2vw, 28px);
  padding-bottom: 16px;
  margin-bottom: clamp(24px, 3vw, 40px);
  border-bottom: 1px solid var(--line-soft);
}
.chapter__num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(28px, 3.4vw, 44px);
  line-height: 0.9;
  letter-spacing: -0.03em;
  color: var(--cyan);
}
.chapter__title {
  font-size: clamp(1.55rem, 2.2vw, 2.15rem);
  line-height: 1.12;
}
.chapter__note {
  writing-mode: vertical-rl;
  text-orientation: mixed;
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  color: var(--muted);
  padding-bottom: 4px;
}

.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5em;
  padding-block: 16px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
}
.breadcrumbs li { display: flex; align-items: center; gap: 0.5em; }
.breadcrumbs li + li::before { content: "/"; color: var(--line); }
.breadcrumbs a:hover { color: var(--cyan); }
.breadcrumbs [aria-current="page"] { color: var(--paper); }

.img-frame {
  position: relative;
  display: block;
  width: 100%;
  aspect-ratio: var(--ratio, 16 / 9);
  overflow: hidden;
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  background:
    radial-gradient(120% 90% at 18% 0%, rgba(53, 240, 208, 0.16), transparent 62%),
    radial-gradient(90% 80% at 92% 100%, rgba(255, 138, 61, 0.18), transparent 60%),
    linear-gradient(180deg, var(--ink-800), var(--ink-950));
}
.img-frame > img,
.img-frame > picture,
.img-frame > picture > img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.img-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  opacity: 0.45;
  background-image: repeating-linear-gradient(90deg, rgba(111, 143, 130, 0.18) 0 1px, transparent 1px 32px);
}
.img-frame--wide { --ratio: 21 / 9; }
.img-frame--tall { --ratio: 3 / 4; }
.img-frame--square { --ratio: 1 / 1; }

.img-frame__label {
  position: absolute;
  left: 12px;
  bottom: 12px;
  z-index: 1;
  padding: 3px 9px;
  border: 1px solid var(--line-soft);
  border-radius: 2px;
  background: rgba(6, 26, 19, 0.78);
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--muted);
}

[data-reveal] { opacity: 1; transform: none; }
.js [data-reveal] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.5s var(--ease), transform 0.5s var(--ease);
}
.js [data-reveal].is-visible { opacity: 1; transform: none; }

/* ---------- 7. Header ---------- */
.site-header {
  position: relative;
  z-index: 75;
}

.skip-link {
  position: fixed;
  top: 10px;
  left: calc(var(--rail-w) + 14px);
  z-index: 200;
  padding: 10px 18px;
  border-radius: 2px;
  background: var(--cyan);
  color: #04201A;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.06em;
  transform: translateY(-180%);
  transition: transform 0.18s var(--ease);
}
.skip-link:focus,
.skip-link:focus-visible { transform: translateY(0); }

/* 左竖框 */
.frame-rail {
  position: fixed;
  top: 0;
  bottom: 0;
  left: 0;
  z-index: 60;
  width: var(--rail-w);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: space-between;
  padding: 14px 0 18px;
  background: linear-gradient(180deg, #08201A 0%, var(--ink-900) 100%);
  border-right: 1px solid var(--line-soft);
}
.frame-rail::before {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  width: 10px;
  pointer-events: none;
  opacity: 0.34;
  background-image: repeating-linear-gradient(to bottom, var(--line) 0 1px, transparent 1px 24px);
}

.rail-brand {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 12px;
}
.rail-brand__mark {
  display: grid;
  place-items: center;
  width: 38px;
  height: 38px;
  border: 1px solid rgba(53, 240, 208, 0.5);
  border-radius: 2px;
  background: linear-gradient(160deg, rgba(53, 240, 208, 0.16), rgba(53, 240, 208, 0.02));
  box-shadow: inset 0 1px 0 rgba(242, 245, 239, 0.12), 0 0 18px rgba(53, 240, 208, 0.14);
  color: var(--cyan);
  font-family: var(--font-head);
  font-size: 18px;
  font-weight: 800;
  line-height: 1;
  transition: border-color 0.18s var(--ease), box-shadow 0.18s var(--ease), color 0.18s var(--ease);
}
.rail-brand:hover .rail-brand__mark {
  border-color: var(--cyan);
  color: var(--paper);
  box-shadow: inset 0 1px 0 rgba(242, 245, 239, 0.16), 0 0 24px rgba(53, 240, 208, 0.36);
}
.rail-brand__word {
  writing-mode: vertical-rl;
  text-orientation: mixed;
  font-size: 10px;
  letter-spacing: 0.34em;
  color: var(--muted);
}

.rail-status {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
}
.rail-status__dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background: var(--amber);
  box-shadow: 0 0 0 3px rgba(255, 200, 87, 0.16), 0 0 12px rgba(255, 200, 87, 0.55);
}
.rail-status__text {
  writing-mode: vertical-rl;
  text-orientation: mixed;
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.24em;
  color: var(--muted);
}

/* 主导航（桌面竖排） */
.site-nav {
  position: fixed;
  top: 50%;
  left: 0;
  z-index: 70;
  width: var(--rail-w);
  max-height: calc(100vh - 280px);
  display: flex;
  flex-direction: column;
  align-items: center;
  overflow-y: auto;
  overflow-x: hidden;
  transform: translateY(-50%);
  scrollbar-width: none;
}
.site-nav::-webkit-scrollbar { display: none; }

.site-nav__list {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  width: 100%;
}
.site-nav__item { width: 100%; }

.site-nav__link {
  position: relative;
  display: block;
  width: 100%;
  padding: 11px 4px;
  border-radius: 2px;
  writing-mode: vertical-rl;
  text-orientation: mixed;
  text-align: center;
  font-size: 12.5px;
  letter-spacing: 0.16em;
  color: var(--muted);
  transition: color 0.18s var(--ease), background 0.18s var(--ease), box-shadow 0.18s var(--ease);
}
.site-nav__link:hover {
  color: var(--paper);
  background: rgba(53, 240, 208, 0.07);
  box-shadow: inset 0 0 0 1px rgba(53, 240, 208, 0.28);
}
.site-nav__link[aria-current="page"] { color: var(--cyan); }
.site-nav__link[aria-current="page"]::before {
  content: "";
  position: absolute;
  top: 5px;
  left: 50%;
  transform: translateX(-50%);
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 10px rgba(53, 240, 208, 0.85);
}

.site-nav__num { display: none; }
.site-nav__label { display: inline; }
.site-nav__note { display: none; }

/* 顶横框 */
.frame-top {
  position: fixed;
  top: 0;
  right: 0;
  left: var(--rail-w);
  z-index: 75;
  height: var(--topbar-h);
  display: flex;
  align-items: center;
  gap: 14px;
  padding-inline: clamp(16px, 2.4vw, 32px);
  background: rgba(6, 26, 19, 0.88);
  border-bottom: 1px solid var(--line-soft);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
}

.frame-top__home {
  display: none;
  align-items: center;
}
.frame-top__mark {
  display: grid;
  place-items: center;
  width: 32px;
  height: 32px;
  border: 1px solid rgba(53, 240, 208, 0.5);
  border-radius: 2px;
  background: rgba(53, 240, 208, 0.1);
  color: var(--cyan);
  font-family: var(--font-head);
  font-size: 15px;
  font-weight: 800;
  line-height: 1;
}

.frame-top__brand {
  display: flex;
  align-items: baseline;
  gap: 0.5em;
  font-size: 12px;
  letter-spacing: 0.2em;
  white-space: nowrap;
}
.frame-top__brand-name { color: var(--paper); font-weight: 650; }
.frame-top__brand-tag { color: var(--muted); }

.frame-top__badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 3px 10px;
  border: 1px solid rgba(255, 200, 87, 0.32);
  border-radius: 99px;
  background: rgba(255, 200, 87, 0.07);
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.12em;
  color: var(--amber);
  white-space: nowrap;
}
.frame-top__badge::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--amber);
  box-shadow: 0 0 8px rgba(255, 200, 87, 0.8);
  flex: none;
}

.frame-top__cta { margin-left: auto; }

.nav-toggle {
  display: none;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
  margin-left: auto;
  border: 1px solid var(--line-soft);
  border-radius: 2px;
  color: var(--paper);
  transition: border-color 0.18s var(--ease), color 0.18s var(--ease), background 0.18s var(--ease);
}
.nav-toggle:hover {
  border-color: var(--cyan);
  color: var(--cyan);
  background: rgba(53, 240, 208, 0.08);
}
.nav-toggle__bars {
  position: relative;
  display: block;
  width: 20px;
  height: 2px;
  background: currentColor;
  transition: background 0.18s var(--ease);
}
.nav-toggle__bars::before,
.nav-toggle__bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 20px;
  height: 2px;
  background: currentColor;
  transition: transform 0.2s var(--ease);
}
.nav-toggle__bars::before { top: -6px; }
.nav-toggle__bars::after { top: 6px; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars { background: transparent; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::before { transform: translateY(6px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::after { transform: translateY(-6px) rotate(-45deg); }

.scroll-meter {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 2px;
  overflow: hidden;
}
.scroll-meter__fill {
  display: block;
  width: 100%;
  height: 100%;
  transform: scaleX(var(--scroll-progress, 0));
  transform-origin: left center;
  background: linear-gradient(90deg, var(--cyan), var(--orange));
  transition: transform 0.12s linear;
}

/* ---------- 8. Footer ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(56px, 7vw, 104px);
  border-top: 1px solid var(--line-soft);
  background: linear-gradient(180deg, rgba(11, 42, 32, 0.92), var(--ink-950) 78%);
}
.site-footer::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  width: 132px;
  height: 2px;
  background: linear-gradient(90deg, var(--cyan), rgba(53, 240, 208, 0));
}

.foot-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.5fr) repeat(3, minmax(0, 1fr));
  gap: clamp(24px, 3.4vw, 52px);
  padding-block: clamp(48px, 6vw, 84px);
}

.foot-brand { display: flex; flex-direction: column; align-items: flex-start; gap: 14px; }
.foot-brand__link {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  transition: opacity 0.18s var(--ease);
}
.foot-brand__link:hover { opacity: 0.86; }
.foot-brand__mark {
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  border: 1px solid rgba(53, 240, 208, 0.45);
  border-radius: 2px;
  background: rgba(53, 240, 208, 0.09);
  color: var(--cyan);
  font-family: var(--font-head);
  font-size: 16px;
  font-weight: 800;
  line-height: 1;
}
.foot-brand__name {
  font-family: var(--font-head);
  font-size: 1.15rem;
  font-weight: 800;
  letter-spacing: 0.06em;
  color: var(--paper);
}
.foot-brand__line {
  font-size: 13px;
  letter-spacing: 0.14em;
  color: var(--muted);
}
.foot-brand__state {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--muted);
}
.foot-brand__dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--amber);
  box-shadow: 0 0 10px rgba(255, 200, 87, 0.6);
  flex: none;
}

.foot-top {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-top: 4px;
  padding: 8px 14px;
  border: 1px solid var(--line-soft);
  border-radius: 2px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--muted);
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease), background 0.18s var(--ease);
}
.foot-top:hover {
  color: var(--cyan);
  border-color: var(--cyan);
  background: rgba(53, 240, 208, 0.08);
}
.foot-top__arrow { font-size: 12px; line-height: 1; }

.foot-col { display: flex; flex-direction: column; gap: 16px; }
.foot-col__title {
  display: flex;
  align-items: baseline;
  gap: 10px;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.18em;
  color: var(--paper);
}
.foot-col__idx {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.1em;
  color: var(--cyan);
}
.foot-col__list { display: flex; flex-direction: column; gap: 10px; }
.foot-col__item { line-height: 1.5; }
.foot-col__link {
  position: relative;
  display: inline-block;
  font-size: 14px;
  color: var(--muted);
  transition: color 0.16s var(--ease);
}
.foot-col__link::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -2px;
  height: 1px;
  background: var(--cyan);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 0.18s var(--ease);
}
.foot-col__link:hover { color: var(--paper); }
.foot-col__link:hover::after { transform: scaleX(1); }

.foot-legal {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 8px 24px;
  padding-block: 18px 26px;
  border-top: 1px solid var(--line-faint);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.06em;
  color: var(--muted);
}
.foot-legal__copy { color: var(--paper); }
.foot-legal__meta { color: var(--muted); }
.foot-legal__addr { color: var(--muted); }

/* ---------- 9. Responsive ---------- */
@media (max-width: 1080px) {
  .foot-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .foot-brand { grid-column: 1 / -1; }
}

@media (max-width: 900px) {
  body { padding-left: 0; }

  .frame-rail { display: none; }
  .frame-top { left: 0; }

  .skip-link { left: 14px; }

  .frame-top__home { display: inline-flex; }
  .frame-top__brand-tag { display: none; }
  .frame-top__badge { display: none; }
  .frame-top__cta { display: none; }
  .nav-toggle { display: inline-flex; margin-left: auto; }

  .site-nav {
    top: var(--topbar-h);
    right: 0;
    bottom: 0;
    left: 0;
    width: auto;
    max-height: none;
    transform: translateX(-101%);
    visibility: hidden;
    overflow-y: auto;
    overscroll-behavior: contain;
    padding: 20px clamp(18px, 5vw, 34px) 32px;
    background: linear-gradient(180deg, var(--ink-900), var(--ink-950) 72%);
    box-shadow: inset -1px 0 0 var(--line-soft);
    transition: transform 0.22s var(--ease), visibility 0.22s var(--ease);
  }
  .site-nav[data-open] {
    transform: translateX(0);
    visibility: visible;
  }

  .site-nav__list { align-items: stretch; gap: 0; }
  .site-nav__item { border-bottom: 1px solid var(--line-faint); }

  .site-nav__link {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 16px 6px;
    writing-mode: horizontal-tb;
    text-align: left;
    font-size: 1.08rem;
    letter-spacing: 0.08em;
    color: var(--paper);
  }
  .site-nav__link:hover { background: rgba(53, 240, 208, 0.06); box-shadow: none; }
  .site-nav__num {
    display: inline-block;
    min-width: 26px;
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: 0.12em;
    color: var(--muted);
  }
  .site-nav__link[aria-current="page"]::before {
    top: 50%;
    left: auto;
    right: 8px;
    transform: translateY(-50%);
  }
  .site-nav__note {
    display: block;
    margin-top: 22px;
    font-family: var(--font-mono);
    font-size: 11.5px;
    letter-spacing: 0.06em;
    color: var(--muted);
  }

  .grid--2,
  .grid--3,
  .split,
  .split--rev { grid-template-columns: minmax(0, 1fr); }

  .chapter { grid-template-columns: auto minmax(0, 1fr); }
  .chapter__note {
    writing-mode: horizontal-tb;
    grid-column: 1 / -1;
    padding-bottom: 0;
    letter-spacing: 0.2em;
  }
}

@media (max-width: 700px) {
  .foot-grid { grid-template-columns: minmax(0, 1fr); }
  .foot-legal { flex-direction: column; align-items: flex-start; }
}

@media (max-width: 560px) {
  .frame-top__brand-name { font-size: 11.5px; letter-spacing: 0.14em; }
  .foot-brand__name { font-size: 1.05rem; }
}

/* ---------- 10. Reduced motion ---------- */
@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;
  }

  [data-reveal],
  .js [data-reveal] {
    opacity: 1 !important;
    transform: none !important;
  }

  .panel:hover { transform: none; }
  .scroll-meter__fill { transition: none; }
}