/* =========================================================
   sa36沙龙国官网 · 共享样式表 /assets/site.css
   夜间索引手册：墨夜蓝底 + 侧边轨道 + 纵向章节长卷
   ========================================================= */

/* ---------- 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, ol, ul, figure, blockquote, dl, dd {
  margin: 0;
}

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

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

button {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
  padding: 0;
  cursor: pointer;
}

a {
  color: inherit;
  text-decoration: none;
}

table {
  border-collapse: collapse;
  border-spacing: 0;
}

/* ---------- 2. 变量 ---------- */
:root {
  --ink: #0A1A28;
  --deep: #10303C;
  --cyan: #37E4D4;
  --orange: #FF8B3D;
  --gold: #C6A96B;
  --wine: #7B2E3E;
  --indigo: #3B3B7A;
  --mist: #EEF3F6;
  --paper: #F4EFE6;
  --graphite: #7C8B98;

  --font-head: 'Oswald', 'Barlow Semi Condensed', 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', sans-serif;
  --font-body: 'Noto Sans SC', 'PingFang SC', 'HarmonyOS Sans SC', 'Microsoft YaHei', sans-serif;
  --font-num: 'Oswald', 'Barlow Semi Condensed', ui-monospace, SFMono-Regular, monospace;

  --rail-w: 88px;
  --rail-w-open: 224px;
  --content-max: 1200px;
  --gutter: clamp(18px, 4vw, 56px);

  --line-gold: rgba(198, 169, 107, 0.20);
  --line-gold-soft: rgba(198, 169, 107, 0.12);
  --line-cyan: rgba(55, 228, 212, 0.24);

  --ease: cubic-bezier(0.4, 0, 0.2, 1);
}

/* ---------- 3. 基础中文排版 ---------- */
html, body {
  min-height: 100%;
}

body {
  background-color: var(--ink);
  color: var(--mist);
  font-family: var(--font-body);
  font-size: 16px;
  font-weight: 400;
  line-height: 1.75;
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-head);
  font-weight: 700;
  line-height: 1.28;
  letter-spacing: -0.01em;
  color: var(--mist);
}

h1 { font-size: clamp(34px, 6.4vw, 64px); }
h2 { font-size: clamp(24px, 3.2vw, 34px); font-weight: 600; }
h3 { font-size: clamp(19px, 2.2vw, 24px); font-weight: 600; }
h4 { font-size: 17px; font-weight: 600; }

p { max-width: 78ch; }

.num,
[data-num] {
  font-family: var(--font-num);
  font-variant-numeric: tabular-nums;
  font-feature-settings: "tnum" 1;
}

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

/* ---------- 4. 焦点与无障碍 ---------- */
:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
  border-radius: 2px;
}

.skip-link {
  position: fixed;
  top: 0;
  left: 0;
  z-index: 200;
  transform: translateY(-140%);
  padding: 12px 20px;
  background: var(--cyan);
  color: #04211F;
  font-weight: 700;
  font-size: 14px;
  letter-spacing: 0.04em;
  border-radius: 0 0 14px 0;
  transition: transform 0.18s var(--ease);
}

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

/* ---------- 5. 布局容器 ---------- */
.wrap {
  width: 100%;
  max-width: var(--content-max);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section {
  padding-block: clamp(56px, 7vw, 110px);
}

.section--tight {
  padding-block: clamp(32px, 4vw, 60px);
}

.prose {
  max-width: 76ch;
}

.prose p + p { margin-top: 1em; }
.prose p + h2, .prose p + h3 { margin-top: 1.6em; }
.prose h2 + p, .prose h3 + p { margin-top: 0.7em; }
.prose ul, .prose ol { margin-top: 0.9em; display: grid; gap: 0.5em; }
.prose li { padding-left: 18px; position: relative; }
.prose li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 8px;
  height: 1px;
  background: var(--gold);
}

.lede {
  font-size: clamp(17px, 2vw, 20px);
  line-height: 1.7;
  color: var(--mist);
  max-width: 64ch;
}

.eyebrow {
  font-family: var(--font-head);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--gold);
}

/* ---------- 6. 栅格 ---------- */
.grid {
  display: grid;
  gap: clamp(18px, 2.6vw, 32px);
  grid-template-columns: 1fr;
}

@media (min-width: 720px) {
  .grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (min-width: 980px) {
  .grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .grid--5-7 { grid-template-columns: 5fr 7fr; }
  .grid--7-5 { grid-template-columns: 7fr 5fr; }
  .grid--4-8 { grid-template-columns: 4fr 8fr; }
}

/* ---------- 7. 页头：跳转、顶部工具栏 ---------- */
.site-header {
  position: relative;
  z-index: 50;
}

.topbar { display: none; }

@media (max-width: 1023px) {
  .topbar {
    position: sticky;
    top: 0;
    z-index: 50;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 10px;
    min-height: 60px;
    padding: 8px 16px;
    background: rgba(10, 26, 40, 0.94);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--line-gold);
  }

  .topbar__brand {
    display: flex;
    align-items: center;
    gap: 10px;
    min-width: 0;
  }

  .topbar__brand-name {
    font-family: var(--font-head);
    font-size: 15px;
    letter-spacing: 0.05em;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
  }

  .topbar__tools {
    display: flex;
    align-items: center;
    gap: 8px;
    flex: 0 0 auto;
  }
}

.brand-mark {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  flex: 0 0 auto;
  font-family: var(--font-num);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: #04211F;
  background: linear-gradient(140deg, var(--cyan) 0%, #17A79C 100%);
  border-radius: 10px 3px 10px 3px;
}

.stamp {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 5px 10px;
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--orange);
  background: rgba(255, 139, 61, 0.08);
  border: 1px solid rgba(255, 139, 61, 0.45);
  border-radius: 999px;
  white-space: nowrap;
  transition: background 0.18s var(--ease), border-color 0.18s var(--ease);
}

.stamp:hover {
  background: rgba(255, 139, 61, 0.18);
  border-color: var(--orange);
}

.stamp__dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--orange);
}

.tool-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 36px;
  padding: 0 12px;
  font-size: 13px;
  color: var(--cyan);
  background: rgba(55, 228, 212, 0.06);
  border: 1px solid rgba(55, 228, 212, 0.4);
  border-radius: 8px 3px 8px 3px;
  transition: background 0.18s var(--ease), border-color 0.18s var(--ease);
}

.tool-btn:hover {
  background: rgba(55, 228, 212, 0.16);
  border-color: var(--cyan);
}

.nav-toggle {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  min-height: 36px;
  padding: 0 12px;
  font-size: 13px;
  color: var(--mist);
  border: 1px solid rgba(198, 169, 107, 0.38);
  border-radius: 8px 3px 8px 3px;
  transition: border-color 0.18s var(--ease), background 0.18s var(--ease);
}

.nav-toggle:hover {
  border-color: var(--gold);
  background: rgba(198, 169, 107, 0.1);
}

.nav-toggle__bars {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 3px;
  width: 16px;
}

.nav-toggle__bars i {
  display: block;
  height: 1.5px;
  width: 100%;
  background: var(--cyan);
  border-radius: 2px;
  transition: transform 0.2s var(--ease), opacity 0.2s var(--ease);
}

.nav-toggle[aria-expanded="true"] .nav-toggle__bars i:nth-child(1) { transform: translateY(4.5px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars i:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle__bars i:nth-child(3) { transform: translateY(-4.5px) rotate(-45deg); }

.nav-toggle__text { letter-spacing: 0.04em; }

/* ---------- 8. 页头：侧边轨道 / 移动抽屉 ---------- */
.rail {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  z-index: 60;
  width: var(--rail-w);
  display: flex;
  flex-direction: column;
  background: var(--deep);
  border-right: 1px solid var(--line-gold);
  overflow-x: hidden;
  overflow-y: auto;
  scrollbar-width: none;
  padding-bottom: 20px;
  transition: width 0.28s var(--ease), transform 0.28s var(--ease);
}

.rail::-webkit-scrollbar { display: none; }

.rail::after {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 2px;
  height: 22%;
  background: linear-gradient(180deg, var(--cyan), rgba(55, 228, 212, 0));
  opacity: 0.55;
  pointer-events: none;
}

.rail__brand {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 20px 24px;
  border-bottom: 1px solid var(--line-gold-soft);
  white-space: nowrap;
}

.rail__brand-text {
  font-family: var(--font-head);
  font-size: 14px;
  letter-spacing: 0.12em;
  color: var(--gold);
  opacity: 0;
  transition: opacity 0.16s var(--ease);
}

.rail__list {
  display: flex;
  flex-direction: column;
  padding: 18px 0;
  margin: 0;
}

.rail__link {
  position: relative;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 13px 22px 13px 26px;
  white-space: nowrap;
  transition: background 0.18s var(--ease);
}

.rail__num {
  flex: 0 0 36px;
  width: 36px;
  text-align: center;
  font-family: var(--font-num);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--graphite);
  font-variant-numeric: tabular-nums;
  transition: color 0.18s var(--ease);
}

.rail__label {
  font-size: 15px;
  color: var(--mist);
  opacity: 0;
  transition: opacity 0.16s var(--ease);
}

.rail__link:hover { background: rgba(55, 228, 212, 0.08); }
.rail__link:hover .rail__num { color: var(--cyan); }

.rail__link[aria-current="page"] {
  background: rgba(55, 228, 212, 0.12);
}

.rail__link[aria-current="page"]::before {
  content: "";
  position: absolute;
  left: 0;
  top: 11px;
  bottom: 11px;
  width: 3px;
  background: var(--cyan);
  border-radius: 0 3px 3px 0;
}

.rail__link[aria-current="page"] .rail__num { color: var(--cyan); }
.rail__link[aria-current="page"] .rail__label { color: var(--mist); font-weight: 500; }

.rail__foot {
  margin-top: auto;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding-top: 16px;
  border-top: 1px solid var(--line-gold-soft);
}

.rail__index {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 11px 22px 11px 26px;
  white-space: nowrap;
  font-size: 15px;
  color: var(--mist);
  transition: background 0.18s var(--ease);
}

.rail__index:hover { background: rgba(55, 228, 212, 0.08); }

.rail__index-mark {
  flex: 0 0 36px;
  width: 36px;
  text-align: center;
  font-size: 16px;
  line-height: 1;
  color: var(--cyan);
}

.rail__cta {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  margin: 0 20px;
  padding: 0 12px;
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: #1B1004;
  background: var(--orange);
  border-radius: 4px 16px 4px 16px;
  white-space: nowrap;
  transition: filter 0.18s var(--ease);
}

.rail__cta:hover { filter: brightness(1.08); }

.rail__cta-short { display: block; }
.rail__cta-text { display: none; }

.rail-scrim {
  position: fixed;
  inset: 0;
  z-index: 55;
  background: rgba(6, 15, 24, 0.72);
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.24s var(--ease), visibility 0.24s var(--ease);
}

.rail-scrim[data-open] {
  opacity: 1;
  visibility: visible;
}

@media (max-width: 1023px) {
  .rail {
    width: min(320px, 84vw);
    transform: translateX(-102%);
    box-shadow: 0 0 60px rgba(0, 0, 0, 0.55);
    transition: transform 0.28s var(--ease);
  }

  .rail[data-open] { transform: translateX(0); }

  .rail__brand-text,
  .rail__label { opacity: 1; }

  .rail__index-mark { color: var(--cyan); }

  .rail__cta-short { display: none; }
  .rail__cta-text { display: block; }
}

@media (min-width: 1024px) {
  .rail-scrim { display: none; }

  .rail:hover,
  .rail:focus-within { width: var(--rail-w-open); }

  .rail:hover .rail__label,
  .rail:focus-within .rail__label,
  .rail:hover .rail__brand-text,
  .rail:focus-within .rail__brand-text {
    opacity: 1;
    transition-delay: 0.08s;
  }

  .rail:hover .rail__cta-short,
  .rail:focus-within .rail__cta-short { display: none; }

  .rail:hover .rail__cta-text,
  .rail:focus-within .rail__cta-text { display: block; }

  body { padding-left: var(--rail-w); }

  .skip-link { left: var(--rail-w); }
}

/* ---------- 9. 站内索引面板 ---------- */
.index-sheet {
  position: fixed;
  inset: 0;
  z-index: 80;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  padding: clamp(16px, 7vh, 76px) 18px 28px;
  background: rgba(5, 13, 21, 0.86);
  backdrop-filter: blur(6px);
  overflow-y: auto;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.2s var(--ease), visibility 0.2s var(--ease);
}

.index-sheet.is-open {
  opacity: 1;
  visibility: visible;
}

.index-sheet__panel {
  width: min(760px, 100%);
  padding: 24px clamp(18px, 3vw, 34px) 30px;
  background: var(--deep);
  border: 1px solid var(--line-cyan);
  border-radius: 6px 28px 6px 28px;
  box-shadow: 0 30px 70px rgba(0, 0, 0, 0.5);
  transform: translateY(-8px);
  transition: transform 0.2s var(--ease);
}

.index-sheet.is-open .index-sheet__panel { transform: none; }

.index-sheet__head {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
}

.index-sheet__eyebrow {
  font-family: var(--font-head);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--gold);
}

.index-sheet__close {
  width: 36px;
  height: 36px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  line-height: 1;
  color: var(--mist);
  border: 1px solid var(--line-gold);
  border-radius: 8px 3px 8px 3px;
  transition: border-color 0.18s var(--ease), color 0.18s var(--ease);
}

.index-sheet__close:hover {
  border-color: var(--cyan);
  color: var(--cyan);
}

.index-sheet__title {
  margin-top: 14px;
  font-size: clamp(22px, 3vw, 30px);
  font-weight: 600;
  letter-spacing: 0.01em;
}

.index-sheet__list {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(196px, 1fr));
  gap: 8px;
  margin-top: 20px;
}

.index-sheet__list a {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  padding: 12px 14px;
  font-size: 15px;
  color: var(--mist);
  background: rgba(238, 243, 246, 0.04);
  border-left: 2px solid rgba(198, 169, 107, 0.42);
  transition: background 0.18s var(--ease), border-color 0.18s var(--ease), transform 0.18s var(--ease);
}

.index-sheet__list a:hover {
  background: rgba(55, 228, 212, 0.1);
  border-left-color: var(--cyan);
  transform: translateX(4px);
}

.index-sheet__list a[aria-current="page"] {
  background: rgba(55, 228, 212, 0.14);
  border-left-color: var(--cyan);
}

.index-sheet__list em {
  font-family: var(--font-num);
  font-style: normal;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--gold);
  font-variant-numeric: tabular-nums;
}

/* ---------- 10. 页脚 ---------- */
.site-footer {
  margin-top: clamp(72px, 9vw, 132px);
  padding: clamp(40px, 5vw, 72px) var(--gutter) 28px;
  background: linear-gradient(180deg, rgba(16, 48, 60, 0.6) 0%, rgba(10, 26, 40, 1) 68%);
  border-top: 1px solid var(--line-gold);
}

.footer-wrap {
  max-width: var(--content-max);
  margin-inline: auto;
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(28px, 3.6vw, 44px);
}

@media (min-width: 720px) {
  .footer-wrap { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (min-width: 1024px) {
  .footer-wrap { grid-template-columns: 1.55fr 1fr 1fr 1fr; }
}

.footer-intro__name {
  margin-top: 14px;
  font-family: var(--font-head);
  font-size: 20px;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--mist);
}

.footer-intro__line {
  margin-top: 8px;
  max-width: 34ch;
  font-size: 14px;
  line-height: 1.7;
  color: var(--graphite);
}

.footer-intro__cta {
  display: inline-flex;
  align-items: center;
  min-height: 42px;
  margin-top: 16px;
  padding: 0 18px;
  font-size: 14px;
  font-weight: 600;
  color: var(--cyan);
  border: 1px solid rgba(55, 228, 212, 0.45);
  border-radius: 4px 16px 4px 16px;
  transition: background 0.18s var(--ease), border-color 0.18s var(--ease);
}

.footer-intro__cta:hover {
  background: rgba(55, 228, 212, 0.12);
  border-color: var(--cyan);
}

.footer-col__title {
  display: flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-head);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.14em;
  color: var(--gold);
}

.footer-col__title::after {
  content: "";
  flex: 1;
  height: 1px;
  background: linear-gradient(90deg, rgba(198, 169, 107, 0.42), rgba(198, 169, 107, 0));
}

.footer-col__list {
  display: flex;
  flex-direction: column;
  gap: 10px;
  margin-top: 16px;
}

.footer-col__list a {
  position: relative;
  display: inline-block;
  padding-left: 10px;
  font-size: 15px;
  color: var(--mist);
  opacity: 0.84;
  transition: color 0.18s var(--ease), opacity 0.18s var(--ease), padding-left 0.18s var(--ease);
}

.footer-col__list a::before {
  content: "";
  position: absolute;
  left: 0;
  top: 50%;
  width: 0;
  height: 1px;
  background: var(--cyan);
  transition: width 0.18s var(--ease);
}

.footer-col__list a:hover {
  color: var(--cyan);
  opacity: 1;
  padding-left: 16px;
}

.footer-col__list a:hover::before { width: 8px; }

.footer-col__list a[aria-current="page"] {
  color: var(--cyan);
  opacity: 1;
}

.footer-base {
  max-width: var(--content-max);
  margin: clamp(32px, 4vw, 56px) auto 0;
  padding-top: 22px;
  border-top: 1px solid var(--line-gold-soft);
  display: flex;
  flex-wrap: wrap;
  gap: 8px 28px;
  align-items: baseline;
  font-size: 13px;
  line-height: 1.7;
  color: var(--graphite);
}

.footer-base__contact {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 18px;
  max-width: none;
}

.footer-base__contact span {
  position: relative;
}

.footer-base__contact span + span::before {
  content: "";
  position: absolute;
  left: -10px;
  top: 50%;
  width: 1px;
  height: 11px;
  background: rgba(198, 169, 107, 0.35);
  transform: translateY(-50%);
}

.footer-base__addr,
.footer-base__note,
.footer-base__legal,
.footer-base__icp {
  max-width: none;
}

.footer-base__legal { color: var(--mist); opacity: 0.72; }

.footer-base__icp {
  font-family: var(--font-num);
  letter-spacing: 0.04em;
  color: var(--gold);
  opacity: 0.9;
}

/* ---------- 11. 通用元件 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 46px;
  padding: 0 22px;
  font-size: 15px;
  font-weight: 600;
  letter-spacing: 0.02em;
  border: 1px solid transparent;
  border-radius: 4px 16px 4px 16px;
  transition: transform 0.18s var(--ease), background 0.18s var(--ease),
              border-color 0.18s var(--ease), color 0.18s var(--ease);
}

.btn:hover { transform: translateY(-2px); }

.btn--cyan { background: var(--cyan); color: #04211F; }
.btn--orange { background: var(--orange); color: #1B1004; }

.btn--ghost {
  color: var(--cyan);
  background: transparent;
  border-color: rgba(55, 228, 212, 0.45);
}

.btn--ghost:hover { background: rgba(55, 228, 212, 0.12); border-color: var(--cyan); }

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.08em;
  color: var(--gold);
  border: 1px solid rgba(198, 169, 107, 0.44);
  border-radius: 999px;
}

.tag--cyan { color: var(--cyan); border-color: rgba(55, 228, 212, 0.46); }
.tag--orange { color: var(--orange); border-color: rgba(255, 139, 61, 0.46); }

.panel {
  padding: clamp(20px, 2.6vw, 32px);
  background: rgba(16, 48, 60, 0.5);
  border: 1px solid rgba(55, 228, 212, 0.16);
  border-radius: 6px 24px 6px 24px;
}

.panel--paper {
  background: var(--paper);
  color: #16232C;
  border-color: rgba(10, 26, 40, 0.14);
}

.panel--paper h2,
.panel--paper h3,
.panel--paper h4 { color: #10222D; }

.panel--paper p { color: #2A3740; }

.panel--paper a {
  color: #0E5B57;
  border-bottom: 1px solid rgba(14, 91, 87, 0.4);
}

.panel--paper a:hover { color: #0A403D; border-bottom-color: #0A403D; }

.card {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: clamp(18px, 2.4vw, 26px);
  background: rgba(16, 48, 60, 0.55);
  border: 1px solid rgba(198, 169, 107, 0.22);
  border-radius: 4px 20px 4px 20px;
  overflow: hidden;
  transition: border-color 0.2s var(--ease), transform 0.2s var(--ease);
}

.card:hover {
  border-color: rgba(55, 228, 212, 0.5);
  transform: translateY(-3px);
}

.card::after {
  content: "";
  position: absolute;
  right: 14px;
  bottom: 12px;
  width: 34px;
  height: 34px;
  background: linear-gradient(135deg,
              transparent 45%,
              rgba(55, 228, 212, 0.5) 45% 51%,
              transparent 51%);
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.18s var(--ease);
}

.card:hover::after { opacity: 1; }

.card__title {
  font-family: var(--font-head);
  font-size: 18px;
  font-weight: 600;
  letter-spacing: 0.01em;
  color: var(--mist);
}

.card__meta {
  font-family: var(--font-num);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--gold);
  font-variant-numeric: tabular-nums;
}

.stat { display: block; }

.stat__num {
  display: block;
  font-family: var(--font-num);
  font-size: clamp(40px, 6vw, 72px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.01em;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

.stat__label {
  display: block;
  margin-top: 10px;
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--graphite);
}

.crumb {
  padding: 18px var(--gutter) 0;
  font-size: 13px;
  color: var(--graphite);
}

.crumb ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  max-width: var(--content-max);
  margin-inline: auto;
}

.crumb li + li::before {
  content: "/";
  margin-right: 8px;
  color: rgba(198, 169, 107, 0.5);
}

.crumb a { color: var(--graphite); transition: color 0.18s var(--ease); }
.crumb a:hover { color: var(--cyan); }
.crumb [aria-current="page"] { color: var(--mist); }

/* ---------- 12. 章节带与专题研究板 ---------- */
.band {
  height: clamp(10px, 1.4vw, 18px);
  background: var(--band, var(--deep));
  border-top: 1px solid var(--line-gold-soft);
  border-bottom: 1px solid var(--line-gold-soft);
}

.chapter-band {
  position: relative;
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 10px 18px;
  padding: 16px var(--gutter) 16px calc(var(--gutter) + 18px);
  background: var(--deep);
  border-top: 1px solid var(--line-gold);
  border-bottom: 1px solid var(--line-gold);
}

.chapter-band::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 10px;
  background: var(--band, var(--cyan));
}

.chapter-band__num {
  font-family: var(--font-num);
  font-size: clamp(28px, 4vw, 46px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.01em;
  color: var(--band, var(--cyan));
  font-variant-numeric: tabular-nums;
}

.chapter-band__title {
  font-family: var(--font-head);
  font-size: clamp(18px, 2.4vw, 26px);
  font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--mist);
}

.chapter-band__hint {
  margin-left: auto;
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--graphite);
}

.board {
  padding: clamp(22px, 3vw, 38px);
  background: rgba(16, 48, 60, 0.5);
  border: 1px solid rgba(55, 228, 212, 0.16);
  border-radius: 6px 26px 6px 26px;
}

.board__summary {
  max-width: 62ch;
  font-size: clamp(17px, 2vw, 20px);
  line-height: 1.68;
  color: var(--mist);
}

.board__summary::before {
  content: "";
  display: block;
  width: 44px;
  height: 3px;
  margin-bottom: 16px;
  background: var(--orange);
}

.board__split {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(20px, 3vw, 40px);
  margin-top: clamp(20px, 3vw, 32px);
}

@media (min-width: 760px) {
  .board__split { grid-template-columns: 5fr 7fr; }
}

.board__label {
  margin-bottom: 12px;
  font-family: var(--font-head);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.16em;
  color: var(--gold);
}

.board__col ul {
  display: grid;
  gap: 10px;
}

.board__col li {
  position: relative;
  padding-left: 18px;
  font-size: 15px;
  line-height: 1.72;
  color: var(--mist);
  opacity: 0.92;
}

.board__col li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.75em;
  width: 8px;
  height: 1px;
  background: var(--cyan);
}

.board__links {
  margin-top: clamp(18px, 2.4vw, 28px);
  padding-top: 16px;
  border-top: 1px dashed rgba(198, 169, 107, 0.32);
  font-size: 14px;
  display: flex;
  flex-wrap: wrap;
  gap: 8px 20px;
  align-items: center;
}

.board__links a {
  color: var(--cyan);
  border-bottom: 1px solid rgba(55, 228, 212, 0.4);
  transition: border-color 0.18s var(--ease), color 0.18s var(--ease);
}

.board__links a:hover { color: var(--mist); border-bottom-color: var(--mist); }

/* ---------- 13. 表格 ---------- */
.table-wrap {
  overflow-x: auto;
  border: 1px solid rgba(198, 169, 107, 0.22);
  border-radius: 4px 14px 4px 14px;
  background: rgba(16, 48, 60, 0.32);
}

table.data {
  width: 100%;
  min-width: 560px;
  font-size: 14px;
}

.data th,
.data td {
  padding: 12px 14px;
  text-align: left;
  vertical-align: top;
  border-bottom: 1px solid rgba(198, 169, 107, 0.14);
}

.data thead th {
  font-family: var(--font-head);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: 0.12em;
  color: var(--gold);
  background: rgba(16, 48, 60, 0.7);
  white-space: nowrap;
}

.data td { color: var(--mist); opacity: 0.92; }
.data td.num { font-variant-numeric: tabular-nums; color: var(--cyan); }
.data tbody tr:hover { background: rgba(55, 228, 212, 0.05); }
.data tbody tr:last-child td { border-bottom: 0; }

/* ---------- 14. 图片容器 ---------- */
.media {
  position: relative;
  display: block;
  width: 100%;
  overflow: hidden;
  background: var(--deep);
  border: 1px solid rgba(198, 169, 107, 0.2);
  border-radius: 4px 22px 4px 22px;
}

.media::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(rgba(55, 228, 212, 0.07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(55, 228, 212, 0.07) 1px, transparent 1px);
  background-size: 28px 28px;
}

.media[data-plain]::after { content: none; }

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

.media--16x9 { aspect-ratio: 16 / 9; }
.media--4x3 { aspect-ratio: 4 / 3; }
.media--1x1 { aspect-ratio: 1 / 1; }
.media--3x4 { aspect-ratio: 3 / 4; }

.media__caption {
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--graphite);
}

/* ---------- 15. 滚动进度与显现 ---------- */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  height: 3px;
  width: 0;
  z-index: 90;
  pointer-events: none;
  background: linear-gradient(90deg, var(--cyan), var(--orange));
}

@media (min-width: 1024px) {
  .scroll-progress { left: var(--rail-w); }
}

html.js [data-reveal] {
  opacity: 0;
  transform: translateY(12px);
  transition: opacity 0.24s var(--ease), transform 0.24s var(--ease);
}

html.js [data-reveal].is-visible {
  opacity: 1;
  transform: none;
}

body.is-locked { overflow: hidden; }

/* ---------- 16. reduced motion ---------- */
@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;
    transition-delay: 0ms !important;
  }

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

  .btn:hover,
  .card:hover { transform: none; }

  .index-sheet__list a:hover { transform: none; }
}