/* ============================================================
   乐竟看台 · /assets/site.css
   共享外壳：reset / tokens / 中文排版 / 头部 / 页脚 / 通用组件
   ============================================================ */

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

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

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

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

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

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

/* ---------- 2. Tokens ---------- */
:root {
  /* 矿物色阶 */
  --ink: #061A14;
  --ink-2: #0B2A20;
  --moss: #1E4A3A;
  --cyan: #6FF2D2;
  --cyan-bright: #8FF7DD;
  --orange: #FF7A1A;
  --orange-soft: rgba(255, 122, 26, 0.16);
  --paper: #F2EDE2;
  --stone: #AEB8B2;
  --clay: #C96F4A;
  --white: #FFFFFF;

  /* 边界与柔光 */
  --line: rgba(174, 184, 178, 0.20);
  --line-strong: rgba(174, 184, 178, 0.42);
  --cyan-soft: rgba(111, 242, 210, 0.12);
  --ink-shadow: 0 18px 44px -30px rgba(0, 0, 0, 0.95);

  /* 尺寸节奏 */
  --shell: 1280px;
  --gutter: clamp(18px, 4vw, 56px);
  --gap: clamp(16px, 2.4vw, 32px);

  /* 字体族 */
  --font-sans: "Helvetica Neue", Helvetica, "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", "Source Han Sans SC", system-ui, -apple-system,
    "Segoe UI", Roboto, sans-serif;
  --font-narrow: "Arial Narrow", "Helvetica Neue Condensed", "PingFang SC",
    "Microsoft YaHei", system-ui, sans-serif;
  --font-mono: ui-monospace, "SFMono-Regular", "JetBrains Mono", Menlo, Consolas,
    "Liberation Mono", monospace;

  /* 动效 */
  --ease: cubic-bezier(0.2, 0.8, 0.2, 1);
  --dur-1: 180ms;
  --dur-2: 260ms;
  --dur-3: 360ms;
}

/* ---------- 3. 基础排版 ---------- */
body {
  min-height: 100vh;
  background:
    radial-gradient(1100px 560px at 84% -12%, rgba(30, 74, 58, 0.62), transparent 64%),
    radial-gradient(900px 520px at 6% 108%, rgba(201, 111, 74, 0.10), transparent 60%),
    var(--ink);
  color: var(--paper);
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.8;
  letter-spacing: 0.01em;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4 {
  font-family: var(--font-narrow);
  font-weight: 800;
  line-height: 1.16;
  letter-spacing: 0.005em;
  text-wrap: balance;
}

p { text-wrap: pretty; }

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

#main-content { scroll-margin-top: 24px; }

/* ---------- 4. 布局容器 ---------- */
.shell {
  width: 100%;
  max-width: var(--shell);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.section { padding-block: clamp(40px, 6vw, 80px); }

.section + .section { border-top: 1px solid var(--line); }

.grid { display: grid; gap: var(--gap); }

.grid--12 { grid-template-columns: repeat(12, minmax(0, 1fr)); }
.grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
.grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }

.span-4 { grid-column: span 4; }
.span-5 { grid-column: span 5; }
.span-6 { grid-column: span 6; }
.span-7 { grid-column: span 7; }
.span-8 { grid-column: span 8; }
.span-12 { grid-column: span 12; }

/* ---------- 5. 跳转链接与进度线 ---------- */
.skip-link {
  position: fixed;
  top: 10px;
  left: 10px;
  z-index: 200;
  padding: 12px 20px;
  background: var(--cyan);
  color: var(--ink);
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.04em;
  border-radius: 2px;
  transform: translateY(-180%);
  transition: transform var(--dur-2) var(--ease);
}

.skip-link:focus-visible {
  transform: translateY(0);
  outline: 2px solid var(--ink);
  outline-offset: 2px;
}

.scroll-progress {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  height: 3px;
  z-index: 120;
  background: rgba(174, 184, 178, 0.14);
  pointer-events: none;
}

.scroll-progress__bar {
  display: block;
  height: 100%;
  width: 100%;
  transform: scaleX(var(--progress, 0));
  transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--cyan) 0%, var(--cyan) 55%, var(--orange) 100%);
  transition: transform 120ms linear;
}

/* ---------- 6. 头部：双层信息导航 ---------- */
.site-header {
  position: relative;
  z-index: 60;
  background: var(--ink);
  border-bottom: 1px solid var(--line);
}

.header-top {
  background: linear-gradient(180deg, var(--ink-2) 0%, #08231A 100%);
  border-bottom: 1px solid var(--line);
}

.header-top__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px clamp(16px, 3vw, 40px);
  padding-block: 14px;
}

.header-top__note {
  flex: 1 1 200px;
  min-width: 0;
  padding-left: clamp(12px, 2vw, 24px);
  border-left: 1px solid var(--line-strong);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.12em;
  color: var(--stone);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.header-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: flex-end;
  margin-left: auto;
}

/* 品牌 */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  min-height: 44px;
  flex: 0 0 auto;
  color: var(--paper);
}

.brand__mark {
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  flex: 0 0 auto;
  background: linear-gradient(155deg, var(--moss) 0%, #07231A 100%);
  color: var(--cyan);
  font-family: var(--font-narrow);
  font-size: 19px;
  font-weight: 800;
  line-height: 1;
  clip-path: polygon(0 0, 100% 0, 100% 74%, 80% 100%, 0 100%);
}

.brand__text {
  display: flex;
  flex-direction: column;
  gap: 1px;
  min-width: 0;
}

.brand__name {
  display: block;
  font-family: var(--font-narrow);
  font-size: 19px;
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: 0.05em;
  color: var(--white);
}

.brand__tagline {
  display: block;
  font-family: var(--font-mono);
  font-size: 10.5px;
  line-height: 1.4;
  letter-spacing: 0.1em;
  color: var(--stone);
}

/* 导航层 */
.header-nav {
  background: var(--ink);
  border-bottom: 1px solid var(--line);
}

.header-nav__inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0;
}

.nav-toggle { display: none; }

.site-nav { display: block; }

.site-nav__list {
  display: flex;
  flex-wrap: wrap;
  align-items: stretch;
}

.site-nav__list > li {
  border-right: 1px solid var(--line);
}

.site-nav__list > li:first-child {
  border-left: 1px solid var(--line);
}

.site-nav__link {
  position: relative;
  display: flex;
  align-items: baseline;
  gap: 8px;
  min-height: 52px;
  padding: 0 clamp(12px, 1.6vw, 22px);
  font-family: var(--font-sans);
  font-size: 14.5px;
  font-weight: 600;
  letter-spacing: 0.04em;
  color: var(--stone);
  transition: color var(--dur-1) var(--ease), background var(--dur-1) var(--ease);
}

.site-nav__link::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 2px;
  background: var(--cyan);
  transform: scaleX(0);
  transform-origin: 0 50%;
  transition: transform var(--dur-2) var(--ease);
}

.site-nav__link:hover {
  color: var(--paper);
  background: rgba(111, 242, 210, 0.05);
}

.site-nav__link:hover::after { transform: scaleX(1); }

.site-nav__link[aria-current="page"] {
  color: var(--white);
  background: rgba(111, 242, 210, 0.08);
}

.site-nav__link[aria-current="page"]::after {
  transform: scaleX(1);
  background: var(--orange);
}

.site-nav__index {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.1em;
  color: var(--stone);
  transition: color var(--dur-1) var(--ease);
}

.site-nav__link:hover .site-nav__index { color: var(--cyan); }
.site-nav__link[aria-current="page"] .site-nav__index { color: var(--orange); }

/* ---------- 7. 通用按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  min-height: 44px;
  padding: 0 18px;
  border: 1px solid transparent;
  border-radius: 2px;
  font-family: var(--font-sans);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.04em;
  line-height: 1;
  transition: background var(--dur-1) var(--ease), color var(--dur-1) var(--ease),
    border-color var(--dur-1) var(--ease), transform var(--dur-1) var(--ease);
}

.btn:active { transform: translateY(1px); }

.btn--primary {
  background: var(--cyan);
  border-color: var(--cyan);
  color: var(--ink);
}

.btn--primary:hover {
  background: var(--cyan-bright);
  border-color: var(--cyan-bright);
}

.btn--ghost {
  background: transparent;
  border-color: var(--line-strong);
  color: var(--paper);
}

.btn--ghost:hover {
  border-color: var(--cyan);
  color: var(--cyan);
}

.btn--accent {
  background: var(--orange);
  border-color: var(--orange);
  color: #1A0A00;
}

.btn--accent:hover {
  background: #FFA15C;
  border-color: #FFA15C;
}

/* ---------- 8. 标记组件 ---------- */
.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--cyan);
}

.eyebrow::before {
  content: "";
  width: 26px;
  height: 1px;
  background: currentColor;
}

.section-index {
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--stone);
}

.tag {
  display: inline-block;
  padding: 3px 8px;
  border: 1px solid var(--line-strong);
  border-radius: 2px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  line-height: 1.5;
  color: var(--stone);
}

.tag--cyan {
  color: var(--cyan);
  border-color: rgba(111, 242, 210, 0.45);
  background: var(--cyan-soft);
}

.tag--accent {
  color: var(--orange);
  border-color: rgba(255, 122, 26, 0.5);
  background: var(--orange-soft);
}

/* ---------- 9. 面包屑 ---------- */
.breadcrumb { margin-block: clamp(20px, 3vw, 34px) 0; }

.breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.1em;
  color: var(--stone);
}

.breadcrumb__list li { display: inline-flex; align-items: center; }

.breadcrumb__list li + li::before {
  content: "/";
  margin-inline: 8px;
  color: rgba(174, 184, 178, 0.45);
}

.breadcrumb__list a:hover { color: var(--cyan); }

.breadcrumb__list [aria-current="page"] { color: var(--paper); }

/* ---------- 10. 正文与纸本区 ---------- */
.prose {
  max-width: 38em;
  font-size: 17px;
  line-height: 1.85;
  color: rgba(242, 237, 226, 0.88);
}

.prose > * + * { margin-top: 1.05em; }

.prose h2 {
  margin-top: 1.9em;
  font-size: clamp(22px, 2.4vw, 28px);
  color: var(--paper);
}

.prose h3 {
  margin-top: 1.6em;
  font-size: 19px;
  color: var(--paper);
}

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

.prose ul,
.prose ol {
  padding-left: 1.35em;
  list-style: disc;
}

.prose ol { list-style: decimal; }

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

.paper {
  --line: rgba(6, 26, 20, 0.16);
  --line-strong: rgba(6, 26, 20, 0.30);
  --stone: #5A6A62;
  background: var(--paper);
  color: var(--ink);
}

.paper .prose { color: rgba(6, 26, 20, 0.86); }
.paper .prose h2,
.paper .prose h3,
.paper .prose strong { color: var(--ink); }
.paper .eyebrow { color: #17503F; }
.paper .section-index { color: #5A6A62; }

/* ---------- 11. 数据表基座 ---------- */
.data-table {
  width: 100%;
  font-size: 14.5px;
  font-variant-numeric: tabular-nums;
}

.data-table caption {
  caption-side: top;
  padding-bottom: 10px;
  text-align: left;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--stone);
}

.data-table th,
.data-table td {
  padding: 12px 14px;
  border-bottom: 1px solid var(--line);
  text-align: left;
}

.data-table thead th {
  background: var(--moss);
  color: var(--paper);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}

.data-table tbody tr:hover { background: rgba(111, 242, 210, 0.05); }

.data-table .num {
  font-family: var(--font-mono);
  text-align: right;
  font-variant-numeric: tabular-nums;
}

/* ---------- 12. 图片容器基座 ---------- */
.media-frame {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  aspect-ratio: 16 / 10;
  border: 1px solid var(--line-strong);
  border-radius: 2px;
  background: linear-gradient(158deg, var(--moss) 0%, var(--ink-2) 58%, #04120E 100%);
}

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

.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  background:
    radial-gradient(80% 62% at 92% -4%, rgba(111, 242, 210, 0.20), transparent 62%),
    linear-gradient(180deg, rgba(6, 26, 20, 0) 46%, rgba(6, 26, 20, 0.58) 100%);
}

.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--square { aspect-ratio: 1 / 1; }
.media-frame--tall { aspect-ratio: 4 / 5; }

.media-frame--paper {
  border-color: rgba(6, 26, 20, 0.25);
  background: linear-gradient(158deg, #E4DDCE 0%, var(--paper) 100%);
}

.media-frame--paper::after {
  background: linear-gradient(180deg, rgba(6, 26, 20, 0) 58%, rgba(6, 26, 20, 0.14) 100%);
}

/* ---------- 13. 滚动显现 ---------- */
.reveal {
  transition: opacity var(--dur-3) var(--ease), transform var(--dur-3) var(--ease);
}

.js-reveal .reveal {
  opacity: 0;
  transform: translateY(16px);
}

.js-reveal .reveal.is-visible {
  opacity: 1;
  transform: none;
}

/* ---------- 14. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: auto;
  padding-block: clamp(44px, 6vw, 76px) 0;
  background: var(--ink-2);
  border-top: 1px solid var(--line-strong);
  color: var(--stone);
}

.site-footer::before {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  height: 2px;
  background: linear-gradient(
    90deg,
    var(--cyan) 0%,
    var(--cyan) 16%,
    var(--orange) 26%,
    rgba(255, 122, 26, 0) 62%
  );
}

.footer-grid {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) repeat(3, minmax(0, 0.8fr));
  gap: clamp(28px, 4vw, 56px);
  padding-bottom: clamp(32px, 4vw, 52px);
  border-bottom: 1px solid var(--line);
}

.footer-brand { min-width: 0; }

.brand--footer { margin-bottom: 16px; }

.brand--footer .brand__name { font-size: 18px; }

.footer-brand__summary {
  max-width: 34em;
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--stone);
}

.footer-col { min-width: 0; }

.footer-col__title {
  margin-bottom: 14px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 500;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--cyan);
}

.footer-links {
  display: grid;
  gap: 2px;
}

.footer-links__link {
  display: inline-flex;
  align-items: center;
  min-height: 40px;
  font-size: 14.5px;
  letter-spacing: 0.02em;
  color: var(--stone);
  transition: color var(--dur-1) var(--ease);
}

.footer-links__link:hover,
.footer-links__link:focus-visible {
  color: var(--paper);
  text-decoration: underline;
  text-decoration-color: var(--cyan);
  text-decoration-thickness: 1px;
  text-underline-offset: 5px;
}

.footer-contact {
  display: grid;
  grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
  gap: clamp(20px, 3vw, 44px);
  padding-block: clamp(24px, 3.5vw, 36px);
  border-bottom: 1px solid var(--line);
}

.footer-contact__list {
  display: flex;
  flex-wrap: wrap;
  gap: 12px clamp(24px, 4vw, 56px);
  margin: 0;
}

.footer-contact__item {
  display: grid;
  gap: 2px;
  min-width: 0;
}

.footer-contact__term {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: 0.16em;
  color: rgba(174, 184, 178, 0.72);
}

.footer-contact__value {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 13.5px;
  font-variant-numeric: tabular-nums;
  color: var(--paper);
  overflow-wrap: anywhere;
}

.footer-contact__note {
  font-size: 13px;
  line-height: 1.8;
  color: var(--stone);
}

.footer-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 10px 24px;
  padding-block: 20px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.06em;
  color: var(--stone);
}

.footer-meta__icp { color: var(--stone); }

.footer-meta__copy { color: rgba(174, 184, 178, 0.75); }

/* ---------- 15. 响应式 ---------- */
@media (max-width: 1100px) {
  .site-nav__link { padding-inline: 12px; font-size: 14px; }
}

@media (max-width: 1020px) {
  .footer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-brand { grid-column: 1 / -1; }
  .footer-contact { grid-template-columns: 1fr; }
}

@media (max-width: 960px) {
  .header-top__note { display: none; }
  .header-top__inner { justify-content: space-between; }

  .header-nav__inner {
    display: block;
    padding-block: 0;
  }

  .nav-toggle {
    display: flex;
    align-items: center;
    gap: 12px;
    width: 100%;
    min-height: 54px;
    font-family: var(--font-mono);
    font-size: 12px;
    font-weight: 600;
    letter-spacing: 0.16em;
    text-transform: uppercase;
    color: var(--paper);
  }

  .nav-toggle__label { color: var(--paper); }

  .nav-toggle__bars {
    position: relative;
    display: block;
    width: 18px;
    height: 2px;
    background: var(--cyan);
    transition: background var(--dur-1) var(--ease);
  }

  .nav-toggle__bars::before,
  .nav-toggle__bars::after {
    content: "";
    position: absolute;
    left: 0;
    width: 18px;
    height: 2px;
    background: var(--cyan);
    transition: transform var(--dur-2) 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);
  }

  .site-nav {
    width: 100%;
    max-height: 0;
    opacity: 0;
    overflow: hidden;
    transition: max-height var(--dur-3) var(--ease), opacity var(--dur-2) var(--ease);
  }

  .site-nav[data-open] {
    max-height: 560px;
    opacity: 1;
    overflow-y: auto;
  }

  .site-nav__list { flex-direction: column; }

  .site-nav__list > li,
  .site-nav__list > li:first-child {
    border-left: 0;
    border-right: 0;
    border-top: 1px solid var(--line);
  }

  .site-nav__link {
    min-height: 54px;
    padding: 0;
    font-size: 15px;
  }

  .site-nav__link::after { display: none; }

  .site-nav__index { min-width: 26px; }

  .grid--12 { grid-template-columns: repeat(6, minmax(0, 1fr)); }

  .span-4, .span-5, .span-6, .span-7, .span-8, .span-12 {
    grid-column: 1 / -1;
  }

  .grid--2, .grid--3 { grid-template-columns: 1fr; }
}

@media (max-width: 640px) {
  body { font-size: 15.5px; }

  .header-actions {
    width: 100%;
    margin-left: 0;
  }

  .header-actions .btn {
    flex: 1 1 0;
    padding: 0 12px;
    font-size: 13px;
  }

  .brand__name { font-size: 17px; }
  .brand__tagline { font-size: 10px; }

  .footer-grid { grid-template-columns: 1fr; }
  .footer-contact__list { flex-direction: column; gap: 14px; }

  .footer-meta {
    flex-direction: column;
    align-items: flex-start;
    gap: 6px;
  }

  .prose { font-size: 16px; }
}

/* ---------- 16. 无障碍：减少动态 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }

  *,
  *::before,
  *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }

  .js-reveal .reveal {
    opacity: 1;
    transform: none;
  }

  .scroll-progress__bar { transition: none; }

  .skip-link { transition: none; }
}