/* ==========================================================================
   万博游艺 · 共享样式表 /assets/site.css
   框架式导航 + 纵向叙事长卷 + 近单色深靛体系 + 经幡五色点缀
   ========================================================================== */

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

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

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

ul, ol { padding: 0; list-style: none; }

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

button { font: inherit; color: inherit; }

a { color: inherit; }

table { border-collapse: collapse; width: 100%; }

hr { border: 0; }

/* ---------- 2. 设计变量 ---------- */
:root {
  /* 深靛三级色阶 */
  --ink: #070B14;
  --indigo-900: #0E1730;
  --indigo-800: #1A2844;
  --indigo-700: #2C4066;
  /* 暖砂金 */
  --gold: #D9A24B;
  --gold-soft: #F1D8AC;
  /* 浅阅读底 */
  --paper: #F6F1E7;
  /* 辅助文字 */
  --mist: #9AA3B8;
  /* 经幡五色 */
  --flag-blue: #2E7FB8;
  --flag-red: #C2453C;
  --flag-green: #3E8A63;
  --flag-yellow: #E8B93B;

  /* 骨架尺寸 */
  --bar-h: 64px;
  --rail-w: 96px;
  --rail-open: 272px;

  /* 结构性材质 */
  --frame: 3px solid var(--ink);
  --shadow-hard: 6px 6px 0 var(--ink);
  --shadow-rail: 8px 0 0 rgba(7, 11, 20, 0.4);

  /* 字体 */
  --font-display: "Noto Serif SC", "Source Han Serif SC", "Songti SC", "SimSun", serif;
  --font-sans: "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --font-mono: "IBM Plex Mono", "SFMono-Regular", Menlo, Consolas, "Courier New", monospace;

  --ease: cubic-bezier(0.22, 0.61, 0.36, 1);
}

/* ---------- 3. 中文排版基础 ---------- */
body {
  background: var(--indigo-900);
  color: var(--paper);
  font-family: var(--font-sans);
  font-size: 17px;
  font-weight: 400;
  line-height: 1.75;
  letter-spacing: 0.01em;
  line-break: strict;
  overflow-wrap: break-word;
  min-height: 100vh;
  padding-top: var(--bar-h);
  padding-left: var(--rail-w);
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 800;
  line-height: 1.18;
  letter-spacing: -0.02em;
}

h1 { font-size: clamp(2.4rem, 6vw, 4.6rem); }
h2 { font-size: clamp(1.6rem, 3vw, 2.4rem); }
h3 { font-size: clamp(1.2rem, 2vw, 1.5rem); }

p { text-align: left; }

strong { font-weight: 700; }

::selection {
  background: var(--gold);
  color: var(--ink);
}

#main-content {
  display: block;
  scroll-margin-top: calc(var(--bar-h) + 12px);
}

/* ---------- 4. 焦点与可访问性 ---------- */
:where(a, button, summary, [tabindex]):focus-visible {
  outline: 3px solid var(--gold);
  outline-offset: 3px;
}

.skip-link {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 200;
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 10px 20px;
  background: var(--gold);
  color: var(--ink);
  font-weight: 700;
  text-decoration: none;
  border: var(--frame);
  transform: translateY(-160%);
  transition: transform 0.18s var(--ease);
}

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

/* ---------- 5. 头部：顶条 + 转经筒导航环 ---------- */
.site-header {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: 90;
}

.header-bar {
  position: relative;
  display: flex;
  align-items: center;
  gap: clamp(10px, 1.6vw, 24px);
  height: var(--bar-h);
  padding-inline: clamp(12px, 2.2vw, 26px);
  background: var(--indigo-800);
  border-bottom: var(--frame);
}

/* 品牌 */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-height: 44px;
  flex: 0 0 auto;
  text-decoration: none;
  color: var(--paper);
}

.brand__mark {
  position: relative;
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  border: 3px solid var(--gold);
  border-radius: 50%;
  flex: 0 0 auto;
}

.brand__mark::after {
  content: "";
  position: absolute;
  inset: -8px;
  border: 1px dashed rgba(217, 162, 75, 0.45);
  border-radius: 50%;
}

.brand__ring {
  display: block;
  width: 10px;
  height: 10px;
  background: var(--gold);
  border-radius: 50%;
}

.brand__text {
  display: flex;
  flex-direction: column;
  line-height: 1.15;
}

.brand__word {
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 800;
  letter-spacing: -0.02em;
}

.brand__tag {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.22em;
  color: var(--mist);
  transition: opacity 0.22s var(--ease), transform 0.22s var(--ease);
}

.site-header[data-scrolled] .brand__tag {
  opacity: 0;
  transform: translateY(-4px);
}

/* 顶栏状态信息 */
.header-meta {
  display: flex;
  align-items: center;
  gap: 22px;
  margin-left: auto;
  min-width: 0;
  font-size: 13px;
  color: var(--mist);
  white-space: nowrap;
}

.header-meta__item {
  display: inline-flex;
  align-items: center;
}

.header-meta__dot {
  display: inline-block;
  width: 8px;
  height: 8px;
  margin-right: 7px;
  border-radius: 50%;
  background: var(--flag-green);
}

.header-meta__now {
  margin-left: 4px;
  font-family: var(--font-mono);
  font-weight: 600;
  color: var(--gold-soft);
}

/* 返回顶部 */
.to-top {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  min-height: 44px;
  min-width: 44px;
  padding: 0 14px;
  background: transparent;
  color: var(--gold-soft);
  border: 2px solid var(--indigo-700);
  font-size: 13px;
  line-height: 1;
  cursor: pointer;
  transition: border-color 0.2s, color 0.2s;
}

.to-top:hover {
  border-color: var(--gold);
  color: var(--gold);
}

.to-top__arrow { font-size: 15px; }

.to-top--footer {
  color: var(--paper);
  font-size: 12px;
  letter-spacing: 0.06em;
}

/* 移动导航按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 9px;
  min-height: 44px;
  padding: 0 14px;
  background: var(--gold);
  color: var(--ink);
  border: var(--frame);
  font-weight: 700;
  letter-spacing: 0.04em;
  cursor: pointer;
}

.nav-toggle__bars {
  display: flex;
  flex-direction: column;
  gap: 4px;
  width: 18px;
}

.nav-toggle__bars span {
  display: block;
  height: 2px;
  background: var(--ink);
  transition: transform 0.22s var(--ease), opacity 0.22s var(--ease);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(1) {
  transform: translateY(6px) rotate(45deg);
}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(2) {
  opacity: 0;
}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(3) {
  transform: translateY(-6px) rotate(-45deg);
}

/* 阅读进度 */
.progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 4px;
  background: rgba(44, 64, 102, 0.7);
  overflow: hidden;
}

.progress__bar {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--gold), var(--gold-soft));
  transition: width 0.12s linear;
}

/* 左侧框架导航 */
.nav-frame {
  position: fixed;
  top: var(--bar-h);
  left: 0;
  bottom: 0;
  z-index: 88;
  width: var(--rail-w);
  background: var(--indigo-800);
  border-right: var(--frame);
  overflow: hidden;
  transition: width 0.28s var(--ease);
}

@media (min-width: 901px) {
  .nav-frame:hover,
  .nav-frame:focus-within {
    width: var(--rail-open);
    box-shadow: var(--shadow-rail);
  }
}

.site-nav {
  display: flex;
  flex-direction: column;
  height: 100%;
  padding: 18px 0 22px;
  overflow-y: auto;
  overflow-x: hidden;
}

/* 转经筒环 */
.nav-wheel {
  position: relative;
  display: grid;
  place-items: center;
  width: 56px;
  height: 56px;
  margin: 2px auto 20px;
  border: 3px solid var(--gold);
  border-radius: 50%;
  flex: 0 0 auto;
  transition: transform 0.12s linear;
}

.nav-wheel::before {
  content: "";
  position: absolute;
  inset: 7px;
  border: 1px dashed rgba(217, 162, 75, 0.55);
  border-radius: 50%;
}

.nav-wheel::after {
  content: "";
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--gold);
}

.nav-wheel__mark {
  position: absolute;
  top: -3px;
  left: 50%;
  width: 2px;
  height: 10px;
  background: var(--flag-red);
  transform: translateX(-50%);
}

/* 导航列表 */
.site-nav__list {
  display: flex;
  flex-direction: column;
}

.site-nav__item {
  border-top: 1px solid rgba(44, 64, 102, 0.75);
}

.site-nav__item:last-child {
  border-bottom: 1px solid rgba(44, 64, 102, 0.75);
}

.site-nav__link {
  position: relative;
  display: flex;
  align-items: center;
  gap: 14px;
  min-height: 56px;
  padding: 0 20px;
  color: var(--paper);
  text-decoration: none;
  transition: background 0.18s, color 0.18s;
}

.site-nav__link::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: transparent;
  transition: background 0.18s;
}

.site-nav__link:hover {
  background: rgba(44, 64, 102, 0.55);
  color: var(--gold-soft);
}

.site-nav__link[aria-current="page"] {
  background: rgba(217, 162, 75, 0.1);
  color: var(--gold-soft);
}

.site-nav__link[aria-current="page"]::before {
  background: var(--gold);
}

.site-nav__num {
  flex: 0 0 26px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--mist);
}

.site-nav__link[aria-current="page"] .site-nav__num {
  color: var(--gold);
}

.site-nav__label {
  font-size: 15px;
  font-weight: 500;
  white-space: nowrap;
  opacity: 0;
  transform: translateX(-10px);
  transition: opacity 0.2s var(--ease), transform 0.28s var(--ease);
}

.nav-frame:hover .site-nav__label,
.nav-frame:focus-within .site-nav__label,
.nav-frame[data-open] .site-nav__label {
  opacity: 1;
  transform: translateX(0);
}

/* 导航底部说明 */
.nav-note {
  margin-top: auto;
  padding: 18px 20px 0;
  font-family: var(--font-mono);
  font-size: 12px;
  line-height: 1.7;
  color: var(--mist);
  white-space: nowrap;
  opacity: 0;
  transition: opacity 0.2s var(--ease);
}

.nav-frame:hover .nav-note,
.nav-frame:focus-within .nav-note,
.nav-frame[data-open] .nav-note {
  opacity: 1;
}

/* ---------- 6. 页脚 ---------- */
.site-footer {
  position: relative;
  background: var(--indigo-900);
  color: var(--paper);
  border-top: var(--frame);
}

.footer-ribbon {
  display: flex;
  height: 8px;
}

.footer-ribbon__bar { flex: 1 1 0; }
.footer-ribbon__bar--blue { background: var(--flag-blue); }
.footer-ribbon__bar--white { background: var(--paper); }
.footer-ribbon__bar--red { background: var(--flag-red); }
.footer-ribbon__bar--green { background: var(--flag-green); }
.footer-ribbon__bar--yellow { background: var(--flag-yellow); }

.footer-inner {
  padding-top: clamp(40px, 6vw, 72px);
}

.footer-grid {
  display: grid;
  grid-template-columns: 1.5fr 1fr 1fr 1.4fr;
  gap: clamp(24px, 3.5vw, 56px);
  padding-bottom: clamp(32px, 5vw, 56px);
  border-bottom: 1px solid rgba(44, 64, 102, 0.9);
}

.footer-brand__word {
  font-family: var(--font-display);
  font-size: clamp(24px, 3vw, 32px);
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--gold-soft);
}

.footer-brand__tag {
  margin-top: 10px;
  max-width: 26ch;
  font-size: 14px;
  color: var(--mist);
}

.footer-brand__icp {
  display: inline-block;
  margin-top: 18px;
  padding: 6px 10px;
  border: 2px solid var(--indigo-700);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--paper);
}

.footer-dots {
  display: flex;
  gap: 6px;
  margin-top: 18px;
}

.footer-dots__dot {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  border: 2px solid var(--ink);
}

.footer-dots__dot--blue { background: var(--flag-blue); }
.footer-dots__dot--red { background: var(--flag-red); }
.footer-dots__dot--green { background: var(--flag-green); }
.footer-dots__dot--yellow { background: var(--flag-yellow); }

.footer-col__title {
  margin-bottom: 16px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.24em;
  color: var(--gold);
}

.footer-list {
  display: flex;
  flex-direction: column;
}

.footer-list__link {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  font-size: 15px;
  color: var(--paper);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.18s, border-color 0.18s;
}

.footer-list__link:hover {
  color: var(--gold-soft);
  border-bottom-color: var(--gold);
}

.footer-contact {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer-contact__row {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 12px;
  align-items: baseline;
  font-size: 14px;
  line-height: 1.6;
}

.footer-contact__label {
  padding: 2px 6px;
  border: 1px solid var(--indigo-700);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--gold);
  white-space: nowrap;
}

.footer-contact__value {
  color: var(--paper);
  overflow-wrap: anywhere;
}

.footer-col--contact .btn {
  margin-top: 20px;
  align-self: flex-start;
}

.footer-bottom {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 12px 24px;
  padding-block: 20px 28px;
  color: var(--mist);
}

.footer-bottom__copy {
  margin-right: auto;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
}

.footer-bottom__lang {
  padding: 4px 10px;
  border: 1px solid var(--indigo-700);
  font-family: var(--font-mono);
  font-size: 12px;
}

/* ---------- 7. 通用布局 ---------- */
.wrap {
  width: min(1180px, 100% - clamp(28px, 5vw, 80px));
  margin-inline: auto;
}

.section {
  padding-block: clamp(48px, 7vw, 104px);
}

.section--dark {
  background: var(--indigo-900);
  color: var(--paper);
}

.section--tide {
  background: var(--indigo-800);
  color: var(--paper);
}

.section--paper {
  background: var(--paper);
  color: var(--indigo-900);
  border-block: var(--frame);
}

.grid {
  display: grid;
  gap: clamp(20px, 3vw, 40px);
}

.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
.grid--7-5 { grid-template-columns: 7fr 5fr; }
.grid--8-4 { grid-template-columns: 8fr 4fr; }

/* ---------- 8. 章节推进 ---------- */
.chapter {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 14px;
  margin-bottom: clamp(24px, 3vw, 40px);
}

.chapter::after {
  content: "";
  flex: 1 1 80px;
  min-width: 40px;
  height: 3px;
  align-self: center;
  background: var(--gold);
  opacity: 0.55;
}

.chapter__num {
  font-family: var(--font-mono);
  font-size: clamp(28px, 4vw, 44px);
  font-weight: 600;
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--gold);
}

.chapter__title {
  font-family: var(--font-display);
  font-size: clamp(1.6rem, 3vw, 2.4rem);
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -0.02em;
}

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.24em;
  color: var(--gold);
}

.eyebrow::before {
  content: "";
  width: 24px;
  height: 3px;
  background: var(--gold);
}

.rule {
  height: 3px;
  background: var(--ink);
  margin-block: clamp(28px, 4vw, 56px);
}

.rule--gold { background: var(--gold); }

.num {
  font-family: var(--font-mono);
  font-size: 1.6em;
  font-weight: 600;
  line-height: 1;
  color: var(--gold);
}

/* ---------- 9. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  gap: 0.6em;
  min-height: 44px;
  padding: 12px 22px;
  background: var(--gold);
  color: var(--ink);
  border: var(--frame);
  box-shadow: var(--shadow-hard);
  font-family: var(--font-sans);
  font-weight: 700;
  font-size: 15px;
  letter-spacing: 0.02em;
  text-decoration: none;
  transition: transform 0.18s var(--ease), box-shadow 0.18s var(--ease);
}

.btn:hover {
  transform: translate(3px, 3px);
  box-shadow: 3px 3px 0 var(--ink);
}

.btn--ghost {
  background: transparent;
  color: var(--gold-soft);
  border-color: var(--gold);
  box-shadow: 6px 6px 0 rgba(217, 162, 75, 0.28);
}

.btn--ghost:hover {
  background: rgba(217, 162, 75, 0.12);
  box-shadow: 3px 3px 0 rgba(217, 162, 75, 0.28);
}

.btn--sm {
  padding: 8px 16px;
  font-size: 13px;
  box-shadow: 4px 4px 0 rgba(217, 162, 75, 0.28);
}

/* ---------- 10. 卡片 ---------- */
.card {
  position: relative;
  padding: clamp(20px, 2.6vw, 32px);
  background: var(--indigo-800);
  color: var(--paper);
  border: var(--frame);
  box-shadow: var(--shadow-hard);
}

.card--paper {
  background: var(--paper);
  color: var(--indigo-900);
}

.card h3 { margin-bottom: 12px; }

/* ---------- 11. 正文与引导段 ---------- */
.prose { max-width: 68ch; }

.prose p + p { margin-top: 1.1em; }

.prose ul {
  margin-top: 1em;
  padding-left: 1.35em;
  list-style: disc;
}

.prose ol {
  margin-top: 1em;
  padding-left: 1.35em;
  list-style: decimal;
}

.prose li { margin-top: 0.4em; }

.lead {
  font-size: clamp(1.05rem, 1.6vw, 1.25rem);
  line-height: 1.8;
  color: var(--gold-soft);
}

.section--paper .lead { color: var(--indigo-700); }

/* ---------- 12. 图像容器（供页面阶段使用） ---------- */
.figure {
  position: relative;
  margin: 0;
  background: var(--indigo-800);
  border: var(--frame);
  box-shadow: var(--shadow-hard);
  overflow: hidden;
}

.figure__img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
  background:
    linear-gradient(140deg, var(--indigo-700) 0%, var(--indigo-900) 62%, var(--indigo-800) 100%);
}

.figure::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(246, 241, 231, 0.07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(246, 241, 231, 0.07) 1px, transparent 1px);
  background-size: 48px 48px;
}

.figure--wide .figure__img { aspect-ratio: 21 / 9; }
.figure--tall .figure__img { aspect-ratio: 4 / 5; }

.figure__caption {
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  z-index: 2;
  padding: 10px 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--paper);
  background: linear-gradient(to top, rgba(7, 11, 20, 0.88), rgba(7, 11, 20, 0));
}

/* ---------- 13. 五色标签 ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border: 2px solid currentColor;
  font-family: var(--font-mono);
  font-size: 11px;
  line-height: 1.5;
  letter-spacing: 0.14em;
  white-space: nowrap;
}

.tag--blue { color: var(--flag-blue); }
.tag--red { color: var(--flag-red); }
.tag--green { color: var(--flag-green); }
.tag--yellow { color: var(--flag-yellow); }
.tag--gold { color: var(--gold); }

.section--paper .tag--yellow { color: #8A6A10; }
.section--paper .tag--gold { color: #96661A; }
.section--paper .tag--blue { color: #1F5F8C; }

/* ---------- 14. 面包屑 ---------- */
.breadcrumb { margin-bottom: clamp(20px, 3vw, 32px); }

.breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--mist);
}

.breadcrumb__item {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.breadcrumb__link {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  color: var(--mist);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.18s, border-color 0.18s;
}

.breadcrumb__link:hover {
  color: var(--gold-soft);
  border-bottom-color: var(--gold);
}

.breadcrumb__sep { color: var(--indigo-700); }

.breadcrumb__current { color: var(--gold-soft); }

.section--paper .breadcrumb__list,
.section--paper .breadcrumb__link { color: var(--indigo-700); }

.section--paper .breadcrumb__link:hover {
  color: var(--ink);
  border-bottom-color: var(--gold);
}

.section--paper .breadcrumb__sep { color: var(--indigo-700); }
.section--paper .breadcrumb__current { color: var(--ink); }

/* ---------- 15. 滚动显现 ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.5s var(--ease), transform 0.5s var(--ease);
}

[data-reveal].is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* ---------- 16. 响应式 ---------- */
@media (max-width: 1100px) {
  .header-meta__item--hours { display: none; }
}

@media (max-width: 1024px) {
  .grid--3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-grid { grid-template-columns: 1.4fr 1fr 1fr; }
  .footer-col--contact { grid-column: 1 / -1; }
}

@media (max-width: 900px) {
  body {
    padding-left: 0;
    font-size: 16px;
  }

  .nav-toggle { display: inline-flex; }

  .header-meta { display: none; }

  .header-bar .to-top { margin-left: auto; }

  .to-top__text { display: none; }

  .nav-frame {
    width: min(320px, 86vw);
    transform: translateX(-102%);
    box-shadow: none;
    transition: transform 0.3s var(--ease);
  }

  .nav-frame[data-open] {
    transform: translateX(0);
    box-shadow: var(--shadow-rail);
  }

  .site-nav__label,
  .nav-note {
    opacity: 1;
    transform: translateX(0);
  }

  .site-nav__link { min-height: 52px; }

  .nav-wheel { margin-bottom: 16px; }

  .grid--2,
  .grid--3,
  .grid--7-5,
  .grid--8-4 { grid-template-columns: minmax(0, 1fr); }

  .footer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-brand { grid-column: 1 / -1; }
  .footer-col--contact { grid-column: 1 / -1; }
}

@media (max-width: 640px) {
  .brand__tag { display: none; }

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

  .footer-bottom {
    flex-direction: column;
    align-items: flex-start;
  }

  .footer-bottom__copy { margin-right: 0; }

  .chapter::after { display: none; }
}

/* ---------- 17. 减弱动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }

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

  .nav-frame,
  .nav-wheel,
  .progress__bar { transition: none !important; }
}

/* ---------- 18. 打印 ---------- */
@media print {
  .site-header,
  .site-footer,
  .nav-frame { display: none !important; }

  body {
    padding: 0;
    background: #fff;
    color: #000;
  }
}