/* =========================================================
   AB体育平台 / 共享站套件
   设计依据：深墨绿框架 + 荧光青信号 + 琥珀批次高亮
   ========================================================= */

/* ---------- 1. 设计令牌 ---------- */
:root {
  --ink: #071A14;
  --panel: #0E2A21;
  --line: #1E4A3C;
  --cyan: #47F5D3;
  --cyan-soft: #7CFFE3;
  --teal: #1FA58F;
  --amber: #FFB347;
  --paper: #F2F7F3;
  --mist: #A9C2B8;
  --coral: #FF6B5E;

  --font-display: "Noto Sans SC", "Source Han Sans SC", "HarmonyOS Sans SC", "PingFang SC", system-ui, -apple-system, "Segoe UI", sans-serif;
  --font-body: "Noto Sans SC", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", system-ui, sans-serif;
  --font-serif: "Noto Serif SC", "Source Han Serif SC", "Songti SC", Georgia, serif;
  --font-mono: "IBM Plex Mono", "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;

  --rail: 88px;
  --maxw: 1360px;
  --gutter: clamp(16px, 3vw, 40px);
  --ease: cubic-bezier(.2, .7, .3, 1);
  --step-display: clamp(2.8rem, 6vw, 6rem);
  --step-chapter: clamp(3rem, 8vw, 7rem);
}

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

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

h1, h2, h3, h4, h5, p, figure, blockquote, dl, dd { margin: 0; }
ul, ol { margin: 0; padding: 0; list-style: none; }
img, svg, video, picture { display: block; max-width: 100%; }
a { color: inherit; }
button { font: inherit; color: inherit; }
table { border-collapse: collapse; }

/* ---------- 3. 基础排版 ---------- */
body {
  margin: 0;
  min-height: 100vh;
  background-color: var(--ink);
  background-image: linear-gradient(to right, rgba(30, 74, 60, .30) 1px, transparent 1px);
  background-size: 88px 100%;
  background-position: 0 0;
  color: var(--paper);
  font-family: var(--font-body);
  font-size: 17px;
  line-height: 1.75;
  font-weight: 400;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 800;
  line-height: 1.14;
  letter-spacing: -.015em;
  color: var(--paper);
}

p { margin-block: 0 1em; }
p:last-child { margin-bottom: 0; }

strong { font-weight: 700; color: var(--paper); }
em { font-style: normal; color: var(--cyan); }

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

/* ---------- 4. 可访问性与工具类 ---------- */
:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
  border-radius: 2px;
}

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

.skip-link {
  position: absolute;
  top: 8px;
  left: 12px;
  z-index: 300;
  padding: 10px 18px;
  background: var(--cyan);
  color: var(--ink);
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 800;
  letter-spacing: .04em;
  text-decoration: none;
  clip-path: polygon(0 0, 100% 0, 100% 66%, calc(100% - 14px) 100%, 0 100%);
  transform: translateY(-160%);
  transition: transform .18s var(--ease);
}
.skip-link:focus { transform: translateY(0); }

/* ---------- 5. 布局原语 ---------- */
.container {
  width: 100%;
  max-width: var(--maxw);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

.grid-12 {
  display: grid;
  grid-template-columns: repeat(12, minmax(0, 1fr));
  gap: clamp(12px, 1.6vw, 28px);
}

.prose {
  max-width: 36em;
  color: var(--paper);
  font-size: 17px;
  line-height: 1.78;
}
.prose p { margin-block: 0 1.05em; }
.prose a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(71, 245, 211, .38);
}
.prose a:hover { border-bottom-color: var(--cyan); }

.divider {
  display: block;
  width: 100%;
  height: 1px;
  margin-block: clamp(24px, 3vw, 40px);
  background: var(--line);
  border: 0;
}

/* ---------- 6. 页头框架 ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: 90;
  background: rgba(7, 26, 20, .94);
  -webkit-backdrop-filter: blur(10px) saturate(120%);
  backdrop-filter: blur(10px) saturate(120%);
  border-bottom: 1px solid var(--line);
  transition: box-shadow .2s var(--ease), border-color .2s var(--ease);
}
.site-header[data-scrolled] {
  border-bottom-color: #27604E;
  box-shadow: 0 18px 34px -26px rgba(0, 0, 0, .95);
}

.scroll-progress {
  position: absolute;
  left: 0;
  right: 0;
  bottom: -1px;
  height: 2px;
  background: transparent;
  pointer-events: none;
}
.progress-bar {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--teal), var(--cyan));
  transition: width .1s linear;
}

.header-frame {
  display: grid;
  grid-template-columns: var(--rail) minmax(0, 1fr) auto;
  align-items: stretch;
  max-width: var(--maxw);
  margin-inline: auto;
  padding-right: var(--gutter);
}

/* 左侧竖直铁轨 */
.header-rail {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 12px;
  padding: 10px 0;
  border-right: 1px solid var(--line);
}
.rail-mark {
  writing-mode: vertical-rl;
  text-orientation: mixed;
  font-family: var(--font-mono);
  font-size: 10px;
  font-weight: 600;
  letter-spacing: .30em;
  color: var(--mist);
  text-transform: uppercase;
}
.rail-dot {
  width: 7px;
  height: 7px;
  background: var(--amber);
  clip-path: polygon(50% 0, 100% 50%, 50% 100%, 0 50%);
}

/* 品牌块 */
.brand {
  display: flex;
  align-items: center;
  min-width: 0;
}
.brand-link {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 13px 18px;
  text-decoration: none;
  color: inherit;
}
.brand-mark {
  flex: 0 0 auto;
  display: grid;
  place-items: center;
  width: 40px;
  height: 40px;
  background: var(--cyan);
  color: var(--ink);
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 900;
  letter-spacing: -.03em;
  clip-path: polygon(0 0, 100% 0, 100% 66%, 70% 100%, 0 100%);
  transition: background-color .18s var(--ease);
}
.brand-link:hover .brand-mark { background: var(--amber); }
.brand-text {
  display: flex;
  flex-direction: column;
  gap: 1px;
  min-width: 0;
}
.brand-name {
  font-family: var(--font-display);
  font-size: 1.06rem;
  font-weight: 800;
  letter-spacing: .01em;
  line-height: 1.25;
  color: var(--paper);
}
.brand-descriptor {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .10em;
  color: var(--mist);
  white-space: nowrap;
}

/* 头部工具区 */
.header-tools {
  display: flex;
  align-items: center;
  gap: clamp(10px, 1.4vw, 20px);
  justify-self: end;
  padding-left: 16px;
}
.utility-list {
  display: flex;
  align-items: center;
  gap: 8px;
}
.utility-link {
  display: inline-block;
  padding: 5px 10px;
  border: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .06em;
  color: var(--mist);
  text-decoration: none;
  white-space: nowrap;
  transition: color .16s var(--ease), border-color .16s var(--ease), background-color .16s var(--ease);
}
.utility-link:hover {
  color: var(--ink);
  background: var(--amber);
  border-color: var(--amber);
}
.header-cta {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 38px;
  padding: 0 18px;
  background: var(--cyan);
  color: var(--ink);
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 800;
  letter-spacing: .02em;
  text-decoration: none;
  white-space: nowrap;
  clip-path: polygon(0 0, 100% 0, 100% 62%, calc(100% - 14px) 100%, 0 100%);
  transition: background-color .18s var(--ease), color .18s var(--ease);
}
.header-cta:hover { background: var(--cyan-soft); }

/* 移动端频道按钮 */
.nav-toggle {
  display: none;
  align-items: center;
  gap: 10px;
  min-height: 44px;
  padding: 0 14px;
  background: transparent;
  border: 1px solid var(--line);
  color: var(--paper);
  font-family: var(--font-display);
  font-size: 13px;
  font-weight: 800;
  letter-spacing: .14em;
  cursor: pointer;
  transition: border-color .18s var(--ease), color .18s var(--ease);
}
.nav-toggle:hover { border-color: var(--cyan); color: var(--cyan); }
.nav-toggle-label { line-height: 1; }

.nav-toggle-bars {
  position: relative;
  display: block;
  width: 18px;
  height: 2px;
  background: currentColor;
  transition: background-color .16s var(--ease);
}
.nav-toggle-bars::before,
.nav-toggle-bars::after {
  content: "";
  position: absolute;
  left: 0;
  width: 18px;
  height: 2px;
  background: currentColor;
  transition: transform .2s var(--ease), top .2s 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 { top: 0; transform: rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle-bars::after { top: 0; transform: rotate(-45deg); }

/* ---------- 7. 频道导航条 ---------- */
.site-nav {
  border-top: 1px solid var(--line);
  background: rgba(14, 42, 33, .55);
}
.nav-list {
  display: flex;
  flex-wrap: wrap;
  max-width: var(--maxw);
  margin-inline: auto;
  padding: 0 var(--gutter) 0 var(--rail);
}
.nav-item {
  flex: 0 1 auto;
  border-left: 1px solid var(--line);
}
.nav-item:last-child { border-right: 1px solid var(--line); }
.nav-link {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 11px 22px;
  color: var(--mist);
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 600;
  letter-spacing: .01em;
  text-decoration: none;
  transition: color .16s var(--ease), background-color .16s var(--ease), box-shadow .16s var(--ease);
}
.nav-index {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: .06em;
  color: var(--teal);
  transition: color .16s var(--ease);
}
.nav-label { white-space: nowrap; }
.nav-link:hover {
  color: var(--paper);
  background: var(--panel);
}
.nav-link:hover .nav-index { color: var(--cyan); }
.nav-link:focus-visible { outline-offset: -3px; }
.nav-link[aria-current="page"] {
  color: var(--paper);
  background: var(--panel);
  box-shadow: inset 0 -2px 0 var(--cyan);
}
.nav-link[aria-current="page"] .nav-index { color: var(--amber); }

/* ---------- 8. 页脚 ---------- */
.site-footer {
  position: relative;
  margin-top: clamp(48px, 7vw, 96px);
  background: var(--panel);
  border-top: 1px solid var(--line);
}
.site-footer::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  width: clamp(80px, 16vw, 220px);
  height: 2px;
  background: var(--cyan);
}
.footer-frame {
  max-width: var(--maxw);
  margin-inline: auto;
  padding: clamp(36px, 5vw, 64px) var(--gutter) 24px;
}
.footer-top {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, 2fr);
  gap: clamp(28px, 4vw, 64px);
  align-items: start;
}
.footer-brand { min-width: 0; }
.footer-logo {
  display: inline-block;
  font-family: var(--font-display);
  font-size: clamp(1.55rem, 2.8vw, 2.15rem);
  font-weight: 900;
  line-height: 1.1;
  letter-spacing: -.02em;
  color: var(--paper);
  text-decoration: none;
}
.footer-logo span { color: var(--cyan); }
.footer-logo:hover span { color: var(--amber); }
.footer-summary {
  margin-top: 14px;
  max-width: 30em;
  font-size: 15px;
  line-height: 1.8;
  color: var(--mist);
}
.contact-list {
  display: grid;
  gap: 9px;
  margin-top: 22px;
  padding-top: 18px;
  border-top: 1px solid var(--line);
}
.contact-item {
  display: grid;
  grid-template-columns: 6.2em minmax(0, 1fr);
  gap: 10px;
  align-items: baseline;
}
.contact-label {
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--teal);
}
.contact-value {
  font-size: 14px;
  line-height: 1.6;
  color: var(--paper);
  overflow-wrap: anywhere;
}
.footer-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(16px, 3vw, 40px);
}
.footer-col { min-width: 0; }
.footer-col-title {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 600;
  letter-spacing: .22em;
  text-transform: uppercase;
  color: var(--teal);
}
.footer-links {
  display: grid;
  gap: 7px;
}
.footer-link {
  display: inline-block;
  padding: 2px 0;
  font-size: 15px;
  line-height: 1.6;
  color: var(--paper);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color .16s var(--ease), border-color .16s var(--ease);
}
.footer-link:hover {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}
.footer-meta {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 8px 28px;
  margin-top: clamp(28px, 4vw, 48px);
  padding-top: 18px;
  border-top: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .05em;
  color: var(--mist);
}
.footer-legal,
.footer-note { margin: 0; }

/* ---------- 9. 通用组件 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  min-height: 48px;
  padding: 0 24px;
  border: 1px solid var(--line);
  background: transparent;
  color: var(--paper);
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: .02em;
  text-decoration: none;
  cursor: pointer;
  clip-path: polygon(0 0, 100% 0, 100% 64%, calc(100% - 16px) 100%, 0 100%);
  transition: color .18s var(--ease), border-color .18s var(--ease), background-color .18s var(--ease);
}
.btn:hover {
  color: var(--cyan);
  border-color: var(--cyan);
}
.btn--primary {
  background: var(--cyan);
  border-color: var(--cyan);
  color: var(--ink);
}
.btn--primary:hover {
  background: var(--cyan-soft);
  border-color: var(--cyan-soft);
  color: var(--ink);
}
.btn--ghost {
  background: transparent;
  border-color: var(--line);
  color: var(--mist);
}
.btn--ghost:hover {
  color: var(--amber);
  border-color: var(--amber);
}

.panel {
  position: relative;
  padding: clamp(18px, 2vw, 28px);
  background: var(--panel);
  border: 1px solid var(--line);
  transition: border-color .18s var(--ease), transform .18s var(--ease), background-color .18s var(--ease);
}
.panel:hover {
  border-color: var(--cyan);
  transform: translateY(-2px);
}
.panel--cut {
  clip-path: polygon(0 0, calc(100% - 22px) 0, 100% 22px, 100% 100%, 22px 100%, 0 calc(100% - 22px));
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 3px 9px;
  border: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .10em;
  text-transform: uppercase;
  color: var(--mist);
  white-space: nowrap;
}
.tag--cyan { border-color: var(--teal); color: var(--cyan); }
.tag--amber { border-color: var(--amber); color: var(--amber); }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  letter-spacing: .20em;
  text-transform: uppercase;
  color: var(--teal);
}
.eyebrow::before {
  content: "";
  display: block;
  width: 22px;
  height: 1px;
  background: var(--amber);
}

.chapter-no {
  display: block;
  font-family: var(--font-mono);
  font-size: var(--step-chapter);
  font-weight: 700;
  line-height: .84;
  letter-spacing: -.05em;
  color: rgba(71, 245, 211, .16);
  -webkit-text-stroke: 1px rgba(71, 245, 211, .22);
  user-select: none;
}

.section-title {
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 3vw, 2.4rem);
  font-weight: 800;
  line-height: 1.12;
  letter-spacing: -.02em;
  color: var(--paper);
}

.serif-note {
  font-family: var(--font-serif);
  font-size: clamp(1rem, 1.6vw, 1.2rem);
  font-style: normal;
  line-height: 1.85;
  color: var(--mist);
}

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding: 18px 0 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--mist);
}
.breadcrumb-link {
  color: var(--mist);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color .16s var(--ease), border-color .16s var(--ease);
}
.breadcrumb-link:hover {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}
.breadcrumb-sep {
  color: var(--line);
  user-select: none;
}
.breadcrumb [aria-current="page"] { color: var(--paper); }

/* 图片容器基础（页面阶段放置占位图） */
.media-frame {
  position: relative;
  display: block;
  overflow: hidden;
  background: var(--panel);
  border: 1px solid var(--line);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 20px), calc(100% - 20px) 100%, 0 100%);
  transition: border-color .18s var(--ease);
}
.media-frame:hover { border-color: var(--teal); }
.media-frame > img,
.media-frame > picture > img,
.media-frame > video {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  background: linear-gradient(135deg, #123328 0%, #0E2A21 60%, #0A2019 100%);
}
.media-frame--16x9 { aspect-ratio: 16 / 9; }
.media-frame--4x3 { aspect-ratio: 4 / 3; }
.media-frame--1x1 { aspect-ratio: 1 / 1; }
.media-frame--21x9 { aspect-ratio: 21 / 9; }
.media-frame--stacked { aspect-ratio: 3 / 4; }
.media-label {
  position: absolute;
  left: 0;
  bottom: 0;
  padding: 6px 12px;
  background: var(--ink);
  color: var(--cyan);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .14em;
}
.media-caption {
  display: block;
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--mist);
}

/* ---------- 10. 轻动效 ---------- */
[data-reveal] {
  transition: opacity .45s var(--ease), transform .45s var(--ease);
}
html[data-reveal-ready] [data-reveal]:not([data-revealed]) {
  opacity: 0;
  transform: translateY(12px);
}

/* ---------- 11. 响应式 ---------- */
@media (max-width: 1180px) {
  .utility-list { display: none; }
}

@media (max-width: 900px) {
  :root { --rail: 0px; }

  body { background-image: none; }

  .header-frame {
    grid-template-columns: minmax(0, 1fr) auto;
    padding-right: var(--gutter);
  }
  .header-rail { display: none; }
  .nav-toggle { display: inline-flex; }

  .site-nav {
    display: none;
    background: var(--ink);
    border-top: 1px solid var(--line);
  }
  .site-nav[data-open] {
    display: block;
    max-height: calc(100vh - 140px);
    overflow-y: auto;
  }
  .nav-list {
    flex-direction: column;
    flex-wrap: nowrap;
    padding: 0;
  }
  .nav-item {
    border-left: 0;
    border-top: 1px solid var(--line);
  }
  .nav-item:first-child { border-top: 0; }
  .nav-item:last-child { border-right: 0; }
  .nav-link {
    padding: 15px 20px;
    font-size: 16px;
  }
  .nav-link[aria-current="page"] {
    box-shadow: inset 3px 0 0 var(--cyan);
  }

  .footer-top { grid-template-columns: minmax(0, 1fr); }
  .footer-grid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid-12 { grid-template-columns: repeat(6, minmax(0, 1fr)); }
}

@media (max-width: 620px) {
  body { font-size: 16px; }
  .header-cta { display: none; }
  .brand-link { padding: 11px 14px; gap: 10px; }
  .brand-mark { width: 34px; height: 34px; font-size: 13px; }
  .brand-name { font-size: 1rem; }
  .brand-descriptor { display: none; }
  .grid-12 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}

@media (max-width: 520px) {
  .footer-grid { grid-template-columns: minmax(0, 1fr); }
  .footer-meta { flex-direction: column; }
  .contact-item {
    grid-template-columns: minmax(0, 1fr);
    gap: 2px;
  }
  .contact-label { padding-top: 0; }
}

/* ---------- 12. 减弱动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .skip-link,
  .btn,
  .panel,
  .nav-link,
  .footer-link,
  .breadcrumb-link,
  .media-frame,
  .progress-bar,
  .brand-mark,
  .header-cta,
  .utility-link,
  [data-reveal] {
    transition-duration: .001ms !important;
  }
  .panel:hover { transform: none; }
  html[data-reveal-ready] [data-reveal]:not([data-revealed]) {
    opacity: 1;
    transform: none;
  }
}