/* =========================================================
   B体育娱乐看台 / assets/site.css
   共享外壳：变量 · reset · 中文排版 · 头部 · 页脚 · 通用组件
   ========================================================= */

/* ---------- 1. 设计变量 ---------- */
:root {
  --c-night: #08231C;
  --c-stand: #0B0F0E;
  --c-lime: #C8FF3D;
  --c-orange: #FF6A2A;
  --c-line: #F4F7F2;
  --c-red: #E23D3D;
  --c-mist: #8FB7A8;
  --c-glass: #1D3A32;
  --c-paper: #E8D9A8;

  --f-display: "Helvetica Neue", "Arial Narrow", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  --f-body: system-ui, -apple-system, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Noto Sans SC", sans-serif;
  --f-mono: ui-monospace, "SF Mono", "Cascadia Mono", "Roboto Mono", Menlo, Consolas, "Courier New", monospace;

  --w-container: 1240px;
  --pad-x: clamp(16px, 4vw, 48px);
  --h-header: 76px;

  --r-sm: 6px;
  --r-md: 14px;
  --r-lg: 24px;

  --shadow-lift: 0 24px 60px -28px rgba(0, 0, 0, .85);
}

/* ---------- 2. Reset ---------- */
*, *::before, *::after { box-sizing: border-box; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--h-header) + 20px);
}

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

:focus-visible { outline: 2px solid var(--c-lime); outline-offset: 3px; border-radius: 2px; }
::selection { background: var(--c-lime); color: var(--c-night); }

/* ---------- 3. 中文排版与基础节奏 ---------- */
body {
  background-color: var(--c-night);
  color: var(--c-line);
  font-family: var(--f-body);
  font-size: 16px;
  line-height: 1.75;
  letter-spacing: .01em;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

@media (min-width: 960px) { body { font-size: 17px; } }

h1, h2, h3, h4 {
  font-family: var(--f-display);
  font-weight: 800;
  line-height: 1.08;
  letter-spacing: -.015em;
}
h1 { font-size: clamp(44px, 7vw, 112px); }
h2 { font-size: clamp(28px, 3.6vw, 48px); }
h3 { font-size: clamp(20px, 2.4vw, 28px); line-height: 1.25; letter-spacing: -.01em; }
h4 { font-size: clamp(17px, 2vw, 20px); line-height: 1.35; }
p { color: rgba(244, 247, 242, .86); }
strong { color: var(--c-line); font-weight: 700; }

#main-content { padding-top: var(--h-header); }
#main-content[data-flush] { padding-top: 0; }

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

/* ---------- 4. 顶部阅读进度 ---------- */
.scroll-progress {
  position: fixed; top: 0; left: 0; right: 0;
  height: 3px; z-index: 90;
  pointer-events: none;
  background: rgba(244, 247, 242, .08);
}
.scroll-progress-bar {
  display: block; width: 100%; height: 100%;
  transform: scaleX(0); transform-origin: 0 50%;
  background: linear-gradient(90deg, var(--c-lime) 0%, var(--c-orange) 62%, var(--c-red) 100%);
  transition: transform .12s linear;
}

/* ---------- 5. 跳转链接 ---------- */
.skip-link {
  position: fixed; top: -80px; left: clamp(12px, 3vw, 32px);
  z-index: 120;
  padding: 12px 20px;
  border-radius: 0 0 var(--r-sm) var(--r-sm);
  background: var(--c-lime);
  color: var(--c-night);
  font-family: var(--f-display);
  font-weight: 800;
  font-size: 14px;
  letter-spacing: .04em;
  transition: top .22s ease;
}
.skip-link:focus { top: 0; }

/* ---------- 6. 头部 ---------- */
.site-header {
  position: fixed; top: 0; left: 0; right: 0;
  z-index: 60;
  background: transparent;
  border-bottom: 1px solid rgba(143, 183, 168, .12);
  transition: background-color .35s ease, border-color .35s ease, backdrop-filter .35s ease, box-shadow .35s ease;
}
.site-header.is-scrolled {
  background: rgba(11, 15, 14, .94);
  border-bottom-color: rgba(143, 183, 168, .24);
  backdrop-filter: blur(16px) saturate(130%);
  -webkit-backdrop-filter: blur(16px) saturate(130%);
  box-shadow: 0 18px 40px -30px rgba(0, 0, 0, 1);
}

.header-inner {
  max-width: var(--w-container);
  margin-inline: auto;
  padding-inline: var(--pad-x);
  height: var(--h-header);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: clamp(14px, 2vw, 32px);
}

/* 品牌 */
.brand {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  flex: 0 0 auto;
  min-width: 0;
}
.brand-mark {
  position: relative;
  display: block;
  width: 11px;
  height: 30px;
  flex: none;
  background: var(--c-lime);
  transform: skewX(-14deg);
}
.brand-mark::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: 0;
  width: 4px;
  height: 11px;
  background: var(--c-orange);
  transform: translateX(-50%);
}
.brand-text { display: flex; flex-direction: column; min-width: 0; }
.brand-name {
  font-family: var(--f-display);
  font-weight: 800;
  font-size: 17px;
  line-height: 1.25;
  letter-spacing: .01em;
  color: var(--c-line);
  white-space: nowrap;
}
.brand-note {
  font-family: var(--f-mono);
  font-size: 10.5px;
  line-height: 1.4;
  letter-spacing: .1em;
  color: var(--c-mist);
  white-space: nowrap;
}

/* 导航 */
.site-nav {
  display: flex;
  align-items: center;
  gap: clamp(16px, 2.4vw, 36px);
  min-width: 0;
}
.nav-list {
  display: flex;
  align-items: center;
  gap: clamp(12px, 1.7vw, 26px);
}
.nav-list a {
  position: relative;
  display: inline-block;
  padding: 6px 2px;
  font-size: 14.5px;
  font-weight: 600;
  letter-spacing: .02em;
  white-space: nowrap;
  color: rgba(244, 247, 242, .76);
  transition: color .2s ease;
}
.nav-list a::after {
  content: "";
  position: absolute;
  left: 0; right: 0; bottom: -2px;
  height: 2px;
  background: linear-gradient(90deg, var(--c-lime), var(--c-orange));
  transform: scaleX(0);
  transform-origin: 0 50%;
  transition: transform .28s ease;
}
.nav-list a:hover,
.nav-list a:focus-visible { color: var(--c-line); }
.nav-list a:hover::after,
.nav-list a:focus-visible::after { transform: scaleX(1); }
.nav-list a[aria-current="page"] { color: var(--c-lime); }
.nav-list a[aria-current="page"]::after { transform: scaleX(1); }

.nav-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  flex: none;
  padding: 11px 20px;
  border-radius: 999px;
  background: var(--c-lime);
  color: var(--c-night);
  font-family: var(--f-display);
  font-weight: 800;
  font-size: 13.5px;
  letter-spacing: .03em;
  line-height: 1;
  white-space: nowrap;
  transition: transform .2s ease, box-shadow .25s ease, background-color .2s ease;
}
.nav-cta:hover,
.nav-cta:focus-visible {
  transform: translateY(-1px);
  box-shadow: 0 10px 26px -8px rgba(200, 255, 61, .55);
}

/* 移动导航按钮（桌面隐藏） */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 9px;
  padding: 9px 14px;
  border: 1px solid rgba(143, 183, 168, .42);
  border-radius: 999px;
  color: var(--c-line);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .08em;
  transition: border-color .2s ease, background-color .2s ease;
}
.nav-toggle:hover { border-color: rgba(200, 255, 61, .6); }
.nav-toggle-bars { position: relative; display: block; width: 16px; height: 10px; flex: none; }
.nav-toggle-bars::before,
.nav-toggle-bars::after {
  content: "";
  position: absolute; left: 0;
  width: 16px; height: 2px;
  background: var(--c-lime);
  transition: transform .25s ease, top .25s ease;
}
.nav-toggle-bars::before { top: 0; }
.nav-toggle-bars::after { top: 8px; }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::before { top: 4px; transform: rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::after { top: 4px; transform: rotate(-45deg); }
.nav-toggle-text { line-height: 1; }

/* ---------- 7. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(48px, 8vw, 120px);
  background: var(--c-stand);
  color: var(--c-line);
  border-top: 1px solid rgba(143, 183, 168, .2);
  padding: clamp(38px, 6vw, 76px) 0 clamp(22px, 3vw, 34px);
  overflow: hidden;
}
.site-footer::before {
  content: "";
  position: absolute;
  top: -1px; left: 0;
  width: min(42%, 460px);
  height: 3px;
  background: linear-gradient(90deg, var(--c-lime), var(--c-orange));
}
.site-footer::after {
  content: "";
  position: absolute;
  right: -140px; bottom: -220px;
  width: 460px; height: 460px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(29, 58, 50, .8) 0%, transparent 70%);
  pointer-events: none;
}

.footer-inner {
  position: relative;
  z-index: 1;
  max-width: var(--w-container);
  margin-inline: auto;
  padding-inline: var(--pad-x);
}

.footer-top {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 1.55fr);
  gap: clamp(32px, 5vw, 80px);
  align-items: start;
}

.brand--footer { margin-bottom: 20px; }
.brand--footer .brand-name { font-size: 20px; }
.brand--footer .brand-mark { height: 34px; }

.footer-line {
  font-family: var(--f-display);
  font-weight: 800;
  font-size: clamp(15px, 1.6vw, 18px);
  line-height: 1.5;
  letter-spacing: .01em;
  color: var(--c-line);
  max-width: 26ch;
}
.footer-summary {
  margin-top: 10px;
  font-size: 14px;
  line-height: 1.8;
  color: rgba(244, 247, 242, .64);
  max-width: 34ch;
}
.footer-badge {
  display: inline-block;
  margin-top: 18px;
  padding: 6px 12px;
  border: 1px solid rgba(200, 255, 61, .42);
  border-radius: 2px;
  background: rgba(200, 255, 61, .07);
  font-family: var(--f-mono);
  font-size: 11.5px;
  letter-spacing: .12em;
  color: var(--c-lime);
}

.footer-cols {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(20px, 3vw, 40px);
}
.footer-col-title {
  margin-bottom: 14px;
  font-family: var(--f-mono);
  font-size: 11.5px;
  font-weight: 700;
  letter-spacing: .16em;
  color: var(--c-mist);
}
.footer-links li + li { margin-top: 2px; }
.footer-links a {
  display: inline-block;
  padding: 5px 0;
  font-size: 14.5px;
  color: rgba(244, 247, 242, .8);
  border-bottom: 1px solid transparent;
  transition: color .2s ease, border-color .2s ease;
}
.footer-links a:hover,
.footer-links a:focus-visible {
  color: var(--c-lime);
  border-bottom-color: rgba(200, 255, 61, .55);
}

.footer-contact {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 44px;
  margin-top: clamp(30px, 4vw, 52px);
  padding-top: clamp(18px, 3vw, 28px);
  border-top: 1px solid rgba(143, 183, 168, .2);
}
.footer-contact-line {
  font-size: 13.5px;
  line-height: 1.7;
  color: rgba(244, 247, 242, .6);
}
.footer-contact-line .mono { color: var(--c-line); }

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 10px 24px;
  margin-top: clamp(20px, 3vw, 30px);
  padding-top: 16px;
  border-top: 1px dashed rgba(143, 183, 168, .22);
  font-size: 12.5px;
  letter-spacing: .04em;
  color: var(--c-mist);
}
.footer-icp { font-family: var(--f-mono); letter-spacing: .02em; }

/* ---------- 8. 版心与段落 ---------- */
.container {
  width: 100%;
  max-width: var(--w-container);
  margin-inline: auto;
  padding-inline: var(--pad-x);
}
.container--wide { max-width: 1440px; }

.section { position: relative; padding-block: clamp(48px, 7vw, 104px); }
.section--tight { padding-block: clamp(28px, 4vw, 56px); }

.section-head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px 24px;
  margin-bottom: clamp(20px, 3vw, 36px);
}
.section-title { font-size: clamp(26px, 3.4vw, 44px); }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  font-family: var(--f-mono);
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--c-orange);
  text-transform: uppercase;
}
.eyebrow::before {
  content: "";
  width: 22px; height: 2px;
  flex: none;
  background: linear-gradient(90deg, var(--c-lime), var(--c-orange));
}

.mono {
  font-family: var(--f-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0;
}

.prose { max-width: 68ch; }
.prose > * + * { margin-top: 1.1em; }
.prose h2 { margin-top: 1.9em; font-size: clamp(24px, 3vw, 34px); }
.prose h3 { margin-top: 1.6em; }
.prose p { color: rgba(244, 247, 242, .86); }
.prose ul, .prose ol { padding-left: 1.25em; }
.prose ul { list-style: disc; }
.prose ol { list-style: decimal; }
.prose li + li { margin-top: .45em; }
.prose li { color: rgba(244, 247, 242, .86); }
.prose a { color: var(--c-lime); border-bottom: 1px solid rgba(200, 255, 61, .38); }
.prose a:hover { border-bottom-color: var(--c-lime); }

/* ---------- 9. 面包屑 ---------- */
.breadcrumb {
  font-size: 13px;
  letter-spacing: .03em;
  color: var(--c-mist);
}
.breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
}
.breadcrumb li + li::before {
  content: "/";
  margin-right: 8px;
  color: rgba(143, 183, 168, .5);
}
.breadcrumb a {
  color: var(--c-mist);
  border-bottom: 1px solid transparent;
  transition: color .2s ease, border-color .2s ease;
}
.breadcrumb a:hover,
.breadcrumb a:focus-visible { color: var(--c-lime); border-bottom-color: currentColor; }
.breadcrumb [aria-current="page"] { color: var(--c-line); }

/* ---------- 10. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 13px 26px;
  border-radius: 999px;
  font-family: var(--f-display);
  font-weight: 800;
  font-size: 14.5px;
  letter-spacing: .03em;
  line-height: 1;
  text-align: center;
  transition: transform .2s ease, box-shadow .25s ease, background-color .2s ease, color .2s ease, border-color .2s ease;
}
.btn--primary { background: var(--c-lime); color: var(--c-night); }
.btn--primary:hover,
.btn--primary:focus-visible {
  transform: translateY(-2px);
  box-shadow: 0 14px 32px -12px rgba(200, 255, 61, .6);
}
.btn--ghost {
  border: 1px solid rgba(244, 247, 242, .32);
  color: var(--c-line);
}
.btn--ghost:hover,
.btn--ghost:focus-visible { border-color: var(--c-lime); color: var(--c-lime); }
.btn--orange { background: var(--c-orange); color: var(--c-night); }
.btn--orange:hover,
.btn--orange:focus-visible {
  transform: translateY(-2px);
  box-shadow: 0 14px 32px -12px rgba(255, 106, 42, .55);
}

/* ---------- 11. 标签 / 档案卡 ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 10px;
  border: 1px solid rgba(255, 106, 42, .42);
  border-radius: 4px;
  background: rgba(255, 106, 42, .08);
  font-family: var(--f-mono);
  font-size: 11.5px;
  letter-spacing: .06em;
  color: var(--c-orange);
}
.tag--lime {
  border-color: rgba(200, 255, 61, .4);
  background: rgba(200, 255, 61, .08);
  color: var(--c-lime);
}

.file-card {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: clamp(18px, 2.4vw, 26px);
  border: 1px solid rgba(143, 183, 168, .22);
  border-left: 3px solid var(--c-lime);
  border-radius: 0 var(--r-md) var(--r-md) 0;
  background: linear-gradient(160deg, rgba(29, 58, 50, .85) 0%, rgba(11, 15, 14, .92) 100%);
  transition: border-left-color .25s ease, transform .25s ease, box-shadow .25s ease;
}
.file-card:hover {
  border-left-color: var(--c-orange);
  transform: translateY(-3px);
  box-shadow: var(--shadow-lift);
}
.file-card-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}
.file-card-tag {
  font-family: var(--f-mono);
  font-size: 11.5px;
  letter-spacing: .12em;
  color: var(--c-orange);
}

/* ---------- 12. 网格 ---------- */
.grid {
  display: grid;
  gap: clamp(16px, 2.6vw, 32px);
  grid-template-columns: repeat(auto-fit, minmax(min(100%, 250px), 1fr));
}
.grid--stair { align-items: start; }
@media (min-width: 960px) {
  .grid--stair > :nth-child(even) { margin-top: clamp(16px, 3vw, 46px); }
}

/* ---------- 13. 图片容器基础规则 ---------- */
.media {
  position: relative;
  overflow: hidden;
  border-radius: var(--r-md);
  background: linear-gradient(150deg, #0F2A22 0%, var(--c-stand) 100%);
  isolation: isolate;
}
.media > img,
.media > picture > img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.media::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  pointer-events: none;
  background-image: radial-gradient(rgba(244, 247, 242, .18) 1px, transparent 1px);
  background-size: 6px 6px;
  opacity: .26;
}
.media--wide { aspect-ratio: 16 / 9; }
.media--tall { aspect-ratio: 3 / 4; }
.media--square { aspect-ratio: 1 / 1; }

/* ---------- 14. 主题筛选 ---------- */
.filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}
.filter-btn {
  padding: 8px 16px;
  border: 1px solid rgba(143, 183, 168, .3);
  border-radius: 999px;
  font-size: 13.5px;
  font-weight: 700;
  letter-spacing: .02em;
  color: rgba(244, 247, 242, .78);
  transition: color .2s ease, border-color .2s ease, background-color .2s ease;
}
.filter-btn:hover,
.filter-btn:focus-visible { color: var(--c-lime); border-color: rgba(200, 255, 61, .5); }
.filter-btn[aria-pressed="true"] {
  background: var(--c-lime);
  border-color: var(--c-lime);
  color: var(--c-night);
}
.filter-item[hidden] { display: none; }

/* ---------- 15. 返回顶部 ---------- */
.to-top {
  position: fixed;
  right: clamp(14px, 3vw, 32px);
  bottom: clamp(14px, 3vw, 32px);
  z-index: 55;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 46px;
  height: 46px;
  border-radius: 50%;
  border: 1px solid rgba(200, 255, 61, .45);
  background: rgba(29, 58, 50, .92);
  color: var(--c-lime);
  opacity: 0;
  visibility: hidden;
  transform: translateY(10px);
  transition: opacity .25s ease, transform .25s ease, visibility .25s ease, background-color .2s ease;
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
}
.to-top::before {
  content: "";
  width: 9px; height: 9px;
  border-left: 2px solid currentColor;
  border-top: 2px solid currentColor;
  transform: rotate(45deg) translate(1px, 1px);
}
.to-top[data-visible] { opacity: 1; visibility: visible; transform: translateY(0); }
.to-top:hover { background: rgba(29, 58, 50, 1); }

/* ---------- 16. 进入视口显现 ---------- */
.js [data-reveal] {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity .6s ease, transform .6s cubic-bezier(.22, .7, .24, 1);
}
.js [data-reveal][data-revealed] {
  opacity: 1;
  transform: none;
}

/* ---------- 17. 响应式 ---------- */
@media (max-width: 1040px) {
  :root { --h-header: 68px; }

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

  .site-nav {
    position: fixed;
    top: var(--h-header);
    left: 0;
    right: 0;
    z-index: 1;
    display: none;
    flex-direction: column;
    align-items: stretch;
    gap: 0;
    padding: 16px var(--pad-x) 30px;
    background: rgba(8, 35, 28, .98);
    border-bottom: 1px solid rgba(143, 183, 168, .24);
    max-height: calc(100vh - var(--h-header));
    overflow-y: auto;
    -webkit-overflow-scrolling: touch;
  }
  .site-nav[data-open] { display: flex; }

  .nav-list {
    flex-direction: column;
    align-items: stretch;
    gap: 0;
  }
  .nav-list li + li { border-top: 1px solid rgba(143, 183, 168, .14); }
  .nav-list a {
    display: block;
    padding: 15px 0;
    font-size: 16px;
    color: rgba(244, 247, 242, .86);
  }
  .nav-list a::after { display: none; }
  .nav-list a[aria-current="page"] { color: var(--c-lime); }

  .nav-cta {
    margin-top: 20px;
    padding: 15px 22px;
    font-size: 15px;
  }
}

@media (max-width: 900px) {
  .footer-top { grid-template-columns: 1fr; }
  .footer-summary { max-width: 46ch; }
}

@media (max-width: 640px) {
  :root { --h-header: 62px; }
  .brand-mark { height: 26px; width: 10px; }
  .brand-name { font-size: 15.5px; }
  .brand-note { display: none; }
  .footer-cols { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-contact { flex-direction: column; gap: 6px; }
  .footer-legal { flex-direction: column; gap: 6px; }
}

@media (max-width: 420px) {
  .nav-toggle-text { display: none; }
  .nav-toggle { padding: 10px 12px; }
}

/* ---------- 18. 无障碍动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }
  .js [data-reveal] { opacity: 1; transform: none; }
  .scroll-progress-bar { transition: none; }
}