/* ============================================================
   第一娱乐会馆 · /assets/site.css
   共享外壳：reset / 变量 / 中文排版 / 刊头 / 轨道 / 页脚 / 基件
   ============================================================ */

/* ---------- 01 Reset ---------- */
*,
*::before,
*::after { box-sizing: border-box; }

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

body {
  margin: 0;
  padding-left: var(--rail-w);
  background: var(--c-obsidian);
  color: var(--c-text);
  font-family: var(--font-body);
  font-size: var(--fs-body);
  line-height: 1.8;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4, p, figure, blockquote { margin: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }
img, svg, video { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button { font: inherit; color: inherit; background: none; border: 0; cursor: pointer; }
table { border-collapse: collapse; width: 100%; }
hr { border: 0; }

/* ---------- 02 Tokens ---------- */
:root {
  --c-obsidian: #0B0D12;
  --c-ink: #121722;
  --c-paper: #F2E9DA;
  --c-paper-ink: #1A1712;
  --c-cyan: #22E3D2;
  --c-cyan-soft: #7FE9DE;
  --c-violet: #8B5CF6;
  --c-violet-night: #241C33;
  --c-gold: #E9B45C;
  --c-mint: #4ADE80;
  --c-text: #C9C6BE;
  --c-text-dim: rgba(201, 198, 190, 0.66);
  --line: rgba(34, 227, 210, 0.18);
  --line-soft: rgba(201, 198, 190, 0.14);
  --shadow-soft: 0 1px 0 rgba(255, 255, 255, 0.03), 0 18px 40px -30px rgba(0, 0, 0, 0.95);
  --radius: 2px;
  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
  --rail-w: 88px;
  --gutter: clamp(18px, 4vw, 56px);
  --shell: 1240px;
  --fs-body: 16.5px;
  --font-display: "Source Han Sans SC", "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-body: "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, -apple-system, sans-serif;
  --font-latin: "Space Grotesk", "Sora", ui-sans-serif, system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, "Courier New", monospace;
}

/* ---------- 03 基础排版 ---------- */
h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 900;
  letter-spacing: -0.02em;
  line-height: 1.25;
  color: var(--c-paper);
}

p { line-height: 1.85; }

strong { color: var(--c-paper); font-weight: 700; }

::selection { background: var(--c-cyan); color: #06120F; }

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

#main-content { display: block; }

.mono {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

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

/* ---------- 04 Skip link ---------- */
.skip-link {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 300;
  transform: translateY(-130%);
  background: var(--c-cyan);
  color: #06120F;
  padding: 12px 20px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  transition: transform 0.24s var(--ease);
}

.skip-link:focus { transform: translateY(0); }

/* ---------- 05 左侧品牌轨道 ---------- */
.rail {
  position: fixed;
  left: 0;
  top: 0;
  bottom: 0;
  width: var(--rail-w);
  z-index: 90;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: space-between;
  padding: 30px 0 24px;
  border-right: 1px solid var(--line);
  background:
    radial-gradient(120% 40% at 50% 0%, rgba(34, 227, 210, 0.14), transparent 62%),
    linear-gradient(180deg, #0B0D12 0%, #121722 54%, #0B0D12 100%);
}

.rail__mark {
  writing-mode: vertical-rl;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 13px;
  letter-spacing: 0.42em;
  color: var(--c-paper);
}

.rail__rule {
  flex: 1 1 auto;
  width: 1px;
  margin: 18px 0;
  background: linear-gradient(180deg, transparent, rgba(34, 227, 210, 0.55), transparent);
}

.rail__index {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--c-cyan);
  text-shadow: 0 0 14px rgba(34, 227, 210, 0.55);
  transition: color 0.3s var(--ease);
}

/* ---------- 06 刊头 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 80;
  border-bottom: 1px solid var(--line);
  background:
    radial-gradient(72% 150% at 50% -46%, rgba(34, 227, 210, 0.13), transparent 70%),
    rgba(11, 13, 18, 0.96);
}

.scroll-bar {
  position: absolute;
  left: 0;
  bottom: -1px;
  width: 100%;
  height: 2px;
  transform: scaleX(var(--progress, 0));
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--c-cyan), var(--c-violet));
  pointer-events: none;
}

.masthead {
  width: 100%;
  max-width: var(--shell);
  margin: 0 auto;
  padding: 0 var(--gutter);
}

.masthead__top {
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto minmax(0, 1fr);
  align-items: center;
  gap: 20px;
  padding: 16px 0 12px;
}

.masthead__locale {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.22em;
  color: var(--c-text-dim);
  line-height: 1.4;
}

.masthead__locale::before {
  content: "";
  width: 6px;
  height: 6px;
  flex: 0 0 auto;
  background: var(--c-cyan);
  box-shadow: 0 0 12px rgba(34, 227, 210, 0.85);
}

.masthead__brand {
  display: inline-flex;
  align-items: flex-end;
  gap: 10px;
  justify-self: center;
  color: var(--c-paper);
  padding: 2px 4px;
  border-bottom: 1px solid transparent;
  transition: border-color 0.28s var(--ease), color 0.28s var(--ease);
}

.masthead__brand-main {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(21px, 2.6vw, 30px);
  letter-spacing: -0.02em;
  line-height: 1;
}

.masthead__brand-tail {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.3em;
  color: var(--c-cyan);
  line-height: 1;
  padding-bottom: 3px;
}

.masthead__brand:hover { border-bottom-color: var(--c-cyan); }
.masthead__brand:hover .masthead__brand-main { color: var(--c-cyan-soft); }

.masthead__actions {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 14px;
}

/* 语言切换 */
.lang {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  line-height: 1;
  color: var(--c-text-dim);
}

.lang__item { transition: color 0.24s var(--ease); }
.lang__item.is-active { color: var(--c-cyan); }
a.lang__item:hover { color: var(--c-cyan-soft); }
.lang__sep { color: rgba(201, 198, 190, 0.32); }

/* 按钮体系 */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 22px;
  border: 1px solid transparent;
  border-radius: var(--radius);
  font-family: var(--font-body);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.06em;
  line-height: 1;
  white-space: nowrap;
  transition: transform 0.26s var(--ease), background-color 0.26s var(--ease),
    border-color 0.26s var(--ease), color 0.26s var(--ease), box-shadow 0.26s var(--ease);
}

.btn--sm { padding: 9px 15px; font-size: 12.5px; letter-spacing: 0.05em; }

.btn--primary {
  background: var(--c-cyan);
  border-color: var(--c-cyan);
  color: #06120F;
  box-shadow: 0 0 0 0 rgba(34, 227, 210, 0.4);
}
.btn--primary:hover {
  background: var(--c-cyan-soft);
  border-color: var(--c-cyan-soft);
  transform: translateY(-1px);
  box-shadow: 0 10px 26px -14px rgba(34, 227, 210, 0.8);
}

.btn--ghost {
  background: transparent;
  border-color: rgba(201, 198, 190, 0.28);
  color: var(--c-paper);
}
.btn--ghost:hover { border-color: var(--c-cyan); color: var(--c-cyan); transform: translateY(-1px); }

.btn--gold {
  background: transparent;
  border-color: rgba(233, 180, 92, 0.55);
  color: var(--c-gold);
}
.btn--gold:hover { background: var(--c-gold); color: #1A1207; transform: translateY(-1px); }

.btn--violet {
  background: transparent;
  border-color: rgba(139, 92, 246, 0.6);
  color: #C4AAF9;
}
.btn--violet:hover { background: var(--c-violet); color: #0B0716; transform: translateY(-1px); }

/* 移动端栏目按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 9px;
  padding: 9px 12px;
  border: 1px solid rgba(201, 198, 190, 0.24);
  border-radius: var(--radius);
  color: var(--c-paper);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  line-height: 1;
  transition: border-color 0.24s var(--ease), color 0.24s var(--ease);
}

.nav-toggle__box { display: grid; gap: 3px; width: 16px; }
.nav-toggle__box span {
  display: block;
  height: 1px;
  background: currentColor;
  transition: transform 0.26s var(--ease), opacity 0.2s var(--ease);
}
.nav-toggle__label { padding-top: 1px; }

.site-header[data-open] .nav-toggle { color: var(--c-cyan); border-color: var(--c-cyan); }
.site-header[data-open] .nav-toggle__box span:nth-child(1) { transform: translateY(4px) rotate(45deg); }
.site-header[data-open] .nav-toggle__box span:nth-child(2) { opacity: 0; }
.site-header[data-open] .nav-toggle__box span:nth-child(3) { transform: translateY(-4px) rotate(-45deg); }

/* 刊头导航 */
.masthead__nav { border-top: 1px solid var(--line-soft); }

.nav__list {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: clamp(8px, 2.2vw, 34px);
  padding: 2px 0;
}

.nav__link {
  position: relative;
  display: inline-flex;
  align-items: baseline;
  gap: 7px;
  padding: 13px 3px;
  font-size: 15px;
  letter-spacing: 0.02em;
  color: var(--c-text);
  transition: color 0.24s var(--ease);
}

.nav__no {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.08em;
  color: rgba(201, 198, 190, 0.42);
  transition: color 0.24s var(--ease);
}

.nav__link::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 6px;
  height: 1px;
  background: var(--c-cyan);
  transform: scaleX(0);
  transform-origin: 0 50%;
  transition: transform 0.32s var(--ease);
}

.nav__link:hover { color: var(--c-paper); }
.nav__link:hover::after { transform: scaleX(1); }
.nav__link:hover .nav__no { color: var(--c-cyan-soft); }

.nav__link[aria-current="page"] { color: var(--c-cyan); }
.nav__link[aria-current="page"] .nav__no { color: var(--c-cyan); }
.nav__link[aria-current="page"]::before {
  content: "";
  position: absolute;
  left: 50%;
  top: 2px;
  width: 5px;
  height: 5px;
  transform: translateX(-50%);
  background: var(--c-cyan);
  box-shadow: 0 0 10px rgba(34, 227, 210, 0.9);
}

/* ---------- 07 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(56px, 8vw, 118px);
  border-top: 1px solid var(--line);
  background: linear-gradient(180deg, var(--c-ink) 0%, var(--c-obsidian) 62%);
  overflow: hidden;
}

.site-footer::before {
  content: "";
  position: absolute;
  right: -14vw;
  top: -22vw;
  width: 56vw;
  height: 56vw;
  background: radial-gradient(circle, rgba(139, 92, 246, 0.17), transparent 62%);
  pointer-events: none;
}

.site-footer::after {
  content: "";
  position: absolute;
  left: -8vw;
  bottom: -20vw;
  width: 40vw;
  height: 40vw;
  background: radial-gradient(circle, rgba(233, 180, 92, 0.09), transparent 64%);
  pointer-events: none;
}

.footer__inner {
  position: relative;
  z-index: 1;
  max-width: var(--shell);
  margin: 0 auto;
  padding: clamp(40px, 6vw, 74px) var(--gutter) 26px;
}

.footer__head {
  display: grid;
  grid-template-columns: minmax(0, 1fr) minmax(0, 1.05fr);
  gap: clamp(18px, 4vw, 60px);
  align-items: end;
  padding-bottom: clamp(26px, 4vw, 46px);
  border-bottom: 1px solid var(--line-soft);
}

.footer__mark {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(27px, 4.4vw, 54px);
  line-height: 1.05;
  letter-spacing: -0.02em;
  color: var(--c-paper);
}

.footer__statement {
  font-size: 15px;
  line-height: 1.95;
  color: var(--c-text-dim);
  max-width: 48ch;
}

.footer__body {
  display: grid;
  grid-template-columns: minmax(0, 1.55fr) minmax(0, 1fr);
  gap: clamp(24px, 4vw, 64px);
  padding: clamp(26px, 4vw, 44px) 0;
  border-bottom: 1px solid var(--line-soft);
}

.footer__cols {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 24px;
}

.footer__col-title {
  font-family: var(--font-mono);
  font-weight: 500;
  font-size: 11px;
  letter-spacing: 0.26em;
  text-transform: uppercase;
  color: var(--c-cyan);
  margin-bottom: 14px;
  line-height: 1.4;
}

.footer__list li + li { margin-top: 9px; }

.footer__list a {
  position: relative;
  font-size: 14.5px;
  color: var(--c-text);
  transition: color 0.22s var(--ease);
}

.footer__list a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -2px;
  width: 100%;
  height: 1px;
  background: var(--c-cyan);
  transform: scaleX(0);
  transform-origin: 0 50%;
  transition: transform 0.26s var(--ease);
}

.footer__list a:hover { color: var(--c-cyan); }
.footer__list a:hover::after { transform: scaleX(1); }

.footer__contact-list li {
  display: flex;
  gap: 12px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--c-text);
}

.footer__contact-list li + li { margin-top: 11px; }

.footer__k {
  flex: 0 0 auto;
  min-width: 44px;
  padding-top: 3px;
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.16em;
  color: var(--c-gold);
  line-height: 1.5;
}

.footer__v { color: var(--c-text); word-break: break-word; }

.footer__v--mono {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.01em;
}

.footer__base {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 24px;
  padding-top: 22px;
}

.footer__legal,
.footer__meta {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  line-height: 1.7;
  color: rgba(201, 198, 190, 0.5);
}

/* ---------- 08 通用容器与章节 ---------- */
.container {
  width: 100%;
  max-width: var(--shell);
  margin: 0 auto;
  padding-left: var(--gutter);
  padding-right: var(--gutter);
}

.section {
  position: relative;
  padding: clamp(48px, 7vw, 96px) 0;
}

.section--panel {
  background: var(--c-ink);
  border-top: 1px solid var(--line-soft);
  border-bottom: 1px solid var(--line-soft);
}

.section--paper {
  background: var(--c-paper);
  color: var(--c-paper-ink);
  border-top: 1px solid rgba(26, 23, 18, 0.16);
  border-bottom: 1px solid rgba(26, 23, 18, 0.16);
}

.section--paper h1,
.section--paper h2,
.section--paper h3,
.section--paper h4 { color: var(--c-paper-ink); }

.section--paper p { color: #2C2820; }
.section--paper .eyebrow { color: #0E7C72; }
.section--paper .eyebrow::before { background: currentColor; }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  line-height: 1.4;
  color: var(--c-cyan);
}

.eyebrow::before {
  content: "";
  width: 24px;
  height: 1px;
  background: currentColor;
  opacity: 0.75;
}

.chapter {
  font-family: var(--font-mono);
  font-size: clamp(30px, 5.4vw, 64px);
  line-height: 1;
  letter-spacing: -0.02em;
  color: rgba(34, 227, 210, 0.16);
  -webkit-text-stroke: 1px rgba(34, 227, 210, 0.5);
}

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

/* ---------- 09 网格与卡片 ---------- */
.grid { display: grid; gap: clamp(16px, 2vw, 28px); }
.grid--12 { grid-template-columns: repeat(12, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }

.card {
  position: relative;
  padding: clamp(18px, 2.2vw, 28px);
  background: var(--c-violet-night);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  box-shadow: var(--shadow-soft);
  transition: transform 0.3s var(--ease), border-color 0.3s var(--ease), box-shadow 0.3s var(--ease);
}

.card:hover {
  transform: translateY(-2px);
  border-color: rgba(34, 227, 210, 0.55);
  box-shadow: 0 18px 44px -28px rgba(34, 227, 210, 0.4);
}

.card--paper {
  background: var(--c-paper);
  color: var(--c-paper-ink);
  border-color: rgba(26, 23, 18, 0.16);
}

.card--gold { border-color: rgba(233, 180, 92, 0.42); }

.card__title {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 20px;
  line-height: 1.4;
  letter-spacing: -0.01em;
  color: var(--c-paper);
  margin-bottom: 8px;
}

.card__text {
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--c-text-dim);
}

.card--paper .card__title { color: var(--c-paper-ink); }
.card--paper .card__text { color: #3B362C; }

/* ---------- 10 标签 ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 9px;
  border: 1px solid currentColor;
  border-radius: var(--radius);
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.14em;
  line-height: 1.6;
  color: var(--c-cyan);
}

.tag::before {
  content: "";
  width: 5px;
  height: 5px;
  background: currentColor;
}

.tag--gold { color: var(--c-gold); }
.tag--violet { color: #B79BF8; }
.tag--mint { color: var(--c-mint); }
.tag--muted { color: var(--c-text-dim); }

/* ---------- 11 面包屑 ---------- */
.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding: 18px 0 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  line-height: 1.6;
  color: var(--c-text-dim);
}

.breadcrumb a { color: var(--c-text-dim); transition: color 0.22s var(--ease); }
.breadcrumb a:hover { color: var(--c-cyan); }
.breadcrumb__sep { opacity: 0.42; }
.breadcrumb [aria-current="page"] { color: var(--c-cyan); }

/* ---------- 12 长文 ---------- */
.prose { max-width: 68ch; }
.prose p { font-size: var(--fs-body); line-height: 1.9; color: var(--c-text); }
.prose p + p { margin-top: 1em; }
.prose h2 {
  font-size: clamp(21px, 2.6vw, 28px);
  margin: 1.7em 0 0.6em;
  color: var(--c-paper);
}
.prose h3 {
  font-size: 18px;
  margin: 1.5em 0 0.5em;
  color: var(--c-paper);
}
.prose ul { margin: 1em 0; }
.prose ul li {
  position: relative;
  padding-left: 18px;
  line-height: 1.9;
  color: var(--c-text);
}
.prose ul li + li { margin-top: 6px; }
.prose ul li::before {
  content: "";
  position: absolute;
  left: 2px;
  top: 0.85em;
  width: 5px;
  height: 5px;
  background: var(--c-cyan);
}
.prose a {
  color: var(--c-cyan);
  border-bottom: 1px solid rgba(34, 227, 210, 0.38);
}
.section--paper .prose p,
.section--paper .prose ul li { color: #2C2820; }
.section--paper .prose a { color: #0E7C72; border-bottom-color: rgba(14, 124, 114, 0.45); }

/* ---------- 13 图片容器基座 ---------- */
.media {
  position: relative;
  display: block;
  width: 100%;
  aspect-ratio: 16 / 10;
  overflow: hidden;
  border: 1px solid var(--line-soft);
  border-radius: var(--radius);
  background:
    radial-gradient(80% 90% at 18% 8%, rgba(34, 227, 210, 0.16), transparent 60%),
    radial-gradient(74% 84% at 92% 84%, rgba(139, 92, 246, 0.2), transparent 62%),
    linear-gradient(160deg, #121722, #0B0D12 70%);
}

.media img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.media::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image: repeating-linear-gradient(180deg, rgba(255, 255, 255, 0.055) 0 1px, transparent 1px 4px);
  opacity: 0.4;
  pointer-events: none;
}

.media--wide { aspect-ratio: 21 / 9; }
.media--tall { aspect-ratio: 3 / 4; }
.media--square { aspect-ratio: 1 / 1; }

.media__caption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
  line-height: 1.7;
  color: var(--c-text-dim);
}

/* ---------- 14 横向模块 ---------- */
.scroller {
  display: flex;
  gap: clamp(14px, 2vw, 22px);
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  padding-bottom: 14px;
  scrollbar-width: thin;
  scrollbar-color: rgba(34, 227, 210, 0.5) transparent;
}

.scroller > * {
  flex: 0 0 clamp(240px, 32vw, 360px);
  scroll-snap-align: start;
}

.scroller::-webkit-scrollbar { height: 4px; }
.scroller::-webkit-scrollbar-track { background: rgba(201, 198, 190, 0.1); }
.scroller::-webkit-scrollbar-thumb { background: rgba(34, 227, 210, 0.5); }

/* ---------- 15 折叠 ---------- */
.fold { border-top: 1px solid var(--line-soft); }

.fold summary {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 18px;
  padding: 16px 0;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 16px;
  line-height: 1.6;
  color: var(--c-paper);
}

.fold summary::-webkit-details-marker { display: none; }

.fold summary::after {
  content: "+";
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-weight: 400;
  color: var(--c-cyan);
  line-height: 1.4;
}

.fold[open] summary::after { content: "–"; }

.fold__body {
  padding: 0 0 18px;
  font-size: 14.5px;
  line-height: 1.9;
  color: var(--c-text-dim);
}

.section--paper .fold { border-top-color: rgba(26, 23, 18, 0.16); }
.section--paper .fold summary { color: var(--c-paper-ink); }
.section--paper .fold__body { color: #2C2820; }

/* ---------- 16 显现动效 ---------- */
.js [data-reveal] {
  opacity: 0;
  transform: translateY(16px);
}

.js [data-reveal].is-in {
  opacity: 1;
  transform: none;
  transition: opacity 0.62s var(--ease), transform 0.62s var(--ease);
  transition-delay: calc(var(--reveal-i, 0) * 90ms);
}

/* ---------- 17 响应式 ---------- */
@media (max-width: 1180px) {
  :root { --rail-w: 64px; }
  .rail__mark { font-size: 12px; letter-spacing: 0.34em; }
}

@media (max-width: 940px) {
  :root { --rail-w: 0px; }
  body { padding-left: 0; }
  .rail { display: none; }

  .masthead__top {
    grid-template-columns: auto 1fr auto;
    gap: 12px;
    padding: 12px 0 10px;
  }
  .masthead__locale { display: none; }
  .masthead__brand { justify-self: start; }
  .masthead__actions { gap: 10px; }
  .lang { display: none; }
  .nav-toggle { display: inline-flex; }

  .masthead__nav {
    max-height: 0;
    opacity: 0;
    overflow: hidden;
    border-top-color: transparent;
    transition: max-height 0.36s var(--ease), opacity 0.26s var(--ease);
  }
  .site-header[data-open] .masthead__nav {
    max-height: 72vh;
    opacity: 1;
    overflow-y: auto;
    border-top-color: var(--line-soft);
  }
  .nav__list {
    flex-direction: column;
    align-items: stretch;
    justify-content: flex-start;
    gap: 0;
    padding: 6px 0 14px;
  }
  .nav__list li + li { border-top: 1px solid rgba(201, 198, 190, 0.1); }
  .nav__link {
    display: flex;
    width: 100%;
    padding: 14px 2px;
    font-size: 16px;
  }
  .nav__link::after { display: none; }
  .nav__link[aria-current="page"]::before {
    position: static;
    transform: none;
    flex: 0 0 auto;
    margin-right: 2px;
    align-self: center;
  }

  .footer__head { grid-template-columns: minmax(0, 1fr); gap: 16px; }
  .footer__body { grid-template-columns: minmax(0, 1fr); gap: 30px; }
  .grid--3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 680px) {
  :root { --fs-body: 16px; }
  .footer__cols { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 22px; }
  .footer__base { justify-content: flex-start; }
  .grid--3,
  .grid--2 { grid-template-columns: minmax(0, 1fr); }
  .breadcrumb { font-size: 10.5px; }
}

@media (max-width: 460px) {
  .nav-toggle__label { display: none; }
  .masthead__brand-main { font-size: 20px; }
}

/* ---------- 18 动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  .js [data-reveal] { transform: none; }
  .js [data-reveal].is-in {
    transition: opacity 0.3s linear;
    transition-delay: 0ms;
  }

  .card:hover,
  .btn:hover,
  .btn--primary:hover,
  .btn--ghost:hover,
  .btn--gold:hover,
  .btn--violet:hover { transform: none; }

  .masthead__nav,
  .nav-toggle__box span,
  .nav__link::after,
  .footer__list a::after,
  .scroll-bar,
  .skip-link { transition-duration: 0.01ms; }

  .scroller { scroll-behavior: auto; }
}