/* =============================================================
   开元·赛场 Kaiyuan Arena · 全站共享样式
   深黑蓝 #0A0F1A · 电光蓝 #00A8FF · 荧光绿 #39FF14 · 橙红 #FF4500
   设计母题：数据长卷 × 竞技场
   ============================================================= */

/* ---------- 变量与基准 ---------- */
:root {
  --bg-deep: #0A0F1A;
  --bg-card: #1E2A3A;
  --bg-card-deep: #141E2C;
  --blue: #00A8FF;
  --green: #39FF14;
  --orange: #FF4500;
  --ink-light: #FFFFFF;
  --ink-body: #B0C4DE;
  --ink-muted: #778899;
  --line-dim: rgba(176, 196, 222, 0.14);
  --line-blue: rgba(0, 168, 255, 0.32);
  --line-green: rgba(57, 255, 20, 0.35);

  --font-display: "Noto Sans SC", "Microsoft YaHei", sans-serif;
  --font-body: "Noto Sans SC", "Microsoft YaHei", sans-serif;
  --font-data: "Roboto Mono", Consolas, monospace;

  --text-base: 16px;
  --container-max: 1220px;
  --sidebar-w: 280px;
  --topbar-h: 64px;
  --header-z: 100;
}

*, *::before, *::after { box-sizing: border-box; }

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

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

body {
  min-width: 320px;
  background: var(--bg-deep);
  color: var(--ink-body);
  font-family: var(--font-body);
  font-size: var(--text-base);
  line-height: 1.75;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

img, picture, svg, video, canvas { display: block; max-width: 100%; }
ul, ol { list-style: none; }

a {
  color: var(--blue);
  text-decoration: none;
  transition: color .2s ease;
}
a:hover { color: var(--green); }

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

[hidden] { display: none !important; }

::selection { background: var(--blue); color: var(--bg-deep); }

/* ---------- 标题与正文 ---------- */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 900;
  line-height: 1.25;
  color: var(--ink-light);
  letter-spacing: .01em;
}
h1 { font-size: clamp(1.9rem, 4vw, 2.75rem); }
h2 { font-size: clamp(1.5rem, 3vw, 2.1rem); }
h3 { font-size: 1.4rem; }
h4 { font-size: 1.15rem; }
h5 { font-size: 1rem; }
h6 { font-size: .9rem; }

#main-content, main { display: block; }

/* ---------- 布局工具 ---------- */
.container {
  width: 100%;
  max-width: var(--container-max);
  margin-inline: auto;
  padding-inline: 1.25rem;
}

.grid { display: grid; gap: 1.25rem; }
@media (min-width: 720px) {
  .grid-cols-2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (min-width: 1080px) {
  .grid-cols-3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
  .grid-cols-4 { grid-template-columns: repeat(4, minmax(0, 1fr)); }
}

/* ---------- 章节体系 ---------- */
.section { padding-block: clamp(2.25rem, 5vw, 4.75rem); }
.section-head { margin-bottom: 1.75rem; }
.section-index {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  font-family: var(--font-data);
  font-size: .78rem;
  font-weight: 700;
  letter-spacing: .18em;
  text-transform: uppercase;
  color: var(--green);
}
.section-index::before {
  content: "";
  width: 28px;
  height: 2px;
  background: var(--green);
  flex: none;
}
.section-title { margin-top: .5rem; }

.lead { font-size: 1.08rem; line-height: 1.75; color: var(--ink-muted); max-width: 760px; }

.text-gradient {
  background: linear-gradient(100deg, var(--blue), var(--green));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

/* ---------- 按钮 ---------- */
.btn {
  position: relative;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: .5rem;
  padding: .82rem 1.4rem;
  font-family: var(--font-display);
  font-size: .9rem;
  font-weight: 700;
  line-height: 1;
  color: var(--ink-light);
  text-decoration: none;
  background: rgba(0, 168, 255, .10);
  border: 1px solid rgba(0, 168, 255, .45);
  transition: background-color .2s ease, border-color .2s ease, color .2s ease;
}
.btn::after {
  content: "";
  position: absolute;
  right: 0;
  bottom: 0;
  width: 12px;
  height: 12px;
  background: linear-gradient(315deg, transparent 50%, rgba(0, 168, 255, .85) 50%);
  pointer-events: none;
}
.btn:hover {
  background: rgba(0, 168, 255, .22);
  border-color: var(--blue);
  color: var(--ink-light);
}
.btn:active { transform: translateY(1px); }

.btn--sm { padding: .5rem .9rem; font-size: .78rem; }
.btn--sm::after { width: 9px; height: 9px; }
.btn--block { display: flex; width: 100%; }
.btn--block .btn-label { flex: 1; text-align: center; }

.btn--ghost {
  background: transparent;
  border-color: rgba(176, 196, 222, .3);
  color: var(--ink-body);
}
.btn--ghost::after { background: linear-gradient(315deg, transparent 50%, rgba(176, 196, 222, .5) 50%); }
.btn--ghost:hover {
  border-color: var(--ink-body);
  background: rgba(176, 196, 222, .06);
  color: var(--ink-light);
}

.btn-subscribe {
  color: #06120A;
  background: var(--green);
  border-color: var(--green);
  font-weight: 900;
}
.btn-subscribe::after { background: linear-gradient(315deg, transparent 50%, rgba(6, 18, 10, .35) 50%); }
.btn-subscribe:hover {
  color: #06120A;
  background: #5FFB46;
  border-color: #5FFB46;
}
.btn-subscribe:hover::after { background: linear-gradient(315deg, transparent 50%, rgba(6, 18, 10, .25) 50%); }

.btn-label { font-weight: 700; }
.btn-arrow { font-family: var(--font-data); font-size: .9rem; line-height: 1; }

/* ---------- 标签 ---------- */
.tag {
  display: inline-flex;
  align-items: center;
  gap: .35rem;
  padding: .2rem .65rem;
  border: 1px solid var(--line-dim);
  background: rgba(0, 168, 255, .08);
  color: var(--ink-body);
  font-family: var(--font-data);
  font-size: .72rem;
  font-weight: 700;
  letter-spacing: .08em;
  text-transform: uppercase;
  line-height: 1.5;
}
.tag--live {
  color: var(--green);
  border-color: var(--line-green);
  background: rgba(57, 255, 20, .08);
}
.tag--hot {
  color: var(--orange);
  border-color: rgba(255, 69, 0, .4);
  background: rgba(255, 69, 0, .08);
}

/* ---------- 页面头与面包屑 ---------- */
.page-head {
  position: relative;
  max-width: var(--container-max);
  margin: 0 auto 2.25rem;
  padding: clamp(2rem, 5vw, 3.5rem) 1.25rem 1.6rem;
  border-bottom: 1px solid var(--line-dim);
}
.page-head::after {
  content: "";
  position: absolute;
  left: 1.25rem;
  bottom: -2px;
  width: 90px;
  height: 3px;
  background: var(--orange);
}
.page-head h1 { margin-bottom: .5rem; }

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .35rem;
  margin-bottom: .85rem;
  font-family: var(--font-data);
  font-size: .76rem;
  color: var(--ink-muted);
}
.breadcrumb li + li::before {
  content: "/";
  margin-right: .35rem;
  opacity: .6;
}
.breadcrumb a { color: var(--ink-muted); }
.breadcrumb a:hover { color: var(--blue); }
.breadcrumb [aria-current="page"] { color: var(--ink-body); }

/* ---------- 卡片与数据 ---------- */
.card {
  position: relative;
  background:
    linear-gradient(155deg, rgba(0, 168, 255, .06), transparent 55%),
    var(--bg-card);
  border: 1px solid var(--line-dim);
  padding: 1.5rem;
  transition: border-color .2s ease, background-color .2s ease;
}
.card:hover {
  border-color: var(--line-blue);
  background-color: var(--bg-card-deep);
}
.card--inset { border-left: 3px solid var(--blue); }

.data-row { display: flex; align-items: baseline; gap: .55rem; }
.data-value {
  font-family: var(--font-data);
  font-size: 1.55rem;
  font-weight: 700;
  line-height: 1.15;
  color: var(--ink-light);
  font-variant-numeric: tabular-nums;
}
.data-value--green { color: var(--green); }
.data-value--orange { color: var(--orange); }
.data-label {
  display: block;
  font-family: var(--font-data);
  font-size: .72rem;
  font-weight: 700;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--ink-muted);
}

/* ---------- 媒体占位容器 ---------- */
.media-frame {
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  background:
    repeating-linear-gradient(-45deg, rgba(0, 168, 255, .04) 0 8px, transparent 8px 16px),
    linear-gradient(135deg, rgba(0, 168, 255, .12), transparent 65%),
    var(--bg-card);
  border: 1px solid var(--line-dim);
}
.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  border: 1px solid rgba(0, 168, 255, .08);
  pointer-events: none;
}
.media-frame--16x9 { aspect-ratio: 16 / 9; }
.media-frame--4x3 { aspect-ratio: 4 / 3; }
.media-frame--21x9 { aspect-ratio: 21 / 9; }
.media-frame img,
.media-frame picture,
.media-frame svg {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.media-frame--cut::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 46px;
  height: 46px;
  background: rgba(0, 168, 255, .4);
  clip-path: polygon(0 0, 100% 0, 0 100%);
  z-index: 1;
  pointer-events: none;
}
.media-caption {
  padding: .55rem .8rem;
  border: 1px solid var(--line-dim);
  border-top: 0;
  background: var(--bg-card-deep);
  font-size: .76rem;
  color: var(--ink-muted);
}

/* ---------- 品牌组合 ---------- */
.brand {
  display: inline-flex;
  align-items: center;
  gap: .8rem;
  color: var(--ink-light);
  text-decoration: none;
}
.brand:hover { color: var(--ink-light); }
.brand-mark {
  flex: none;
  display: grid;
  place-items: center;
  width: 46px;
  height: 46px;
  background: linear-gradient(135deg, var(--blue), var(--green));
  color: #05140B;
  font-family: var(--font-display);
  font-size: 1.35rem;
  font-weight: 900;
  line-height: 1;
  clip-path: polygon(0 0, calc(100% - 11px) 0, 100% 11px, 100% 100%, 11px 100%, 0 calc(100% - 11px));
}
.brand-text {
  display: flex;
  flex-direction: column;
  line-height: 1.3;
}
.brand-text strong {
  font-size: 1.06rem;
  font-weight: 900;
  color: var(--ink-light);
  letter-spacing: .02em;
}
.brand-text small {
  margin-top: .1rem;
  font-size: .7rem;
  letter-spacing: .16em;
  color: var(--ink-muted);
  text-transform: uppercase;
}
.brand--topbar .brand-mark { width: 38px; height: 38px; font-size: 1.1rem; }
.brand--topbar .brand-text {
  font-size: .98rem;
  font-weight: 900;
  color: var(--ink-light);
  white-space: nowrap;
}
.brand--footer .brand-text strong { font-size: 1.22rem; }
.brand--footer .brand-text small { font-size: .72rem; }

/* ---------- 头部（移动优先） ---------- */
.site-header {
  position: sticky;
  top: 0;
  z-index: var(--header-z);
}

.header-topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--topbar-h);
  padding: 0 1rem;
  background: rgba(10, 15, 26, .94);
  border-bottom: 1px solid var(--line-blue);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
}
.topbar-actions {
  display: flex;
  align-items: center;
  gap: .6rem;
}

/* 汉堡按钮 */
.nav-toggle {
  display: inline-flex;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 40px;
  height: 40px;
  padding: 8px;
  border: 1px solid var(--line-blue);
  background: transparent;
  transition: border-color .2s ease, background-color .2s ease;
}
.nav-toggle:hover {
  border-color: var(--blue);
  background: rgba(0, 168, 255, .08);
}
.nav-toggle-bar {
  display: block;
  height: 2px;
  width: 100%;
  background: var(--ink-light);
  transition: transform .2s ease, opacity .2s ease;
}
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* 侧栏 / 抽屉 */
.site-sidebar {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  z-index: calc(var(--header-z) + 10);
  display: flex;
  flex-direction: column;
  width: min(84vw, 320px);
  padding: 1.5rem 1.25rem;
  overflow-y: auto;
  background:
    linear-gradient(160deg, rgba(0, 168, 255, .10), transparent 45%),
    radial-gradient(circle at 20% 85%, rgba(57, 255, 20, .07), transparent 55%),
    linear-gradient(180deg, #101A2A, #0A0F1A);
  border-right: 1px solid var(--line-blue);
  transform: translateX(-103%);
  visibility: hidden;
  transition: transform .3s ease, visibility 0s linear .3s;
}
.site-header[data-open] .site-sidebar {
  transform: translateX(0);
  visibility: visible;
  transition: transform .3s ease, visibility 0s;
  box-shadow: 24px 0 60px rgba(0, 0, 0, .45);
}

.drawer-scrim {
  position: fixed;
  inset: 0;
  z-index: calc(var(--header-z) + 5);
  background: rgba(4, 8, 14, .78);
  opacity: 0;
  visibility: hidden;
  transition: opacity .3s ease, visibility 0s linear .3s;
}
.site-header[data-open] .drawer-scrim {
  opacity: 1;
  visibility: visible;
  transition: opacity .3s ease, visibility 0s;
}

/* 侧栏内容 */
.sidebar-brand {
  padding-bottom: 1.1rem;
  border-bottom: 1px solid var(--line-dim);
}
.site-nav { margin-top: 1.4rem; }
.nav-list { display: flex; flex-direction: column; gap: .35rem; }
.nav-item { margin: 0; }
.nav-link {
  display: flex;
  align-items: center;
  gap: .75rem;
  padding: .72rem .85rem;
  border: 1px solid transparent;
  border-left: 3px solid transparent;
  font-size: .95rem;
  font-weight: 500;
  color: var(--ink-body);
  transition: background-color .2s ease, border-color .2s ease, color .2s ease;
}
.nav-link:hover {
  background: rgba(0, 168, 255, .08);
  border-left-color: var(--blue);
  color: var(--ink-light);
}
.nav-link:hover .nav-index { color: var(--blue); }
.nav-link[aria-current="page"] {
  background: linear-gradient(90deg, rgba(0, 168, 255, .16), rgba(0, 168, 255, .02));
  border-left-color: var(--green);
  color: var(--ink-light);
}
.nav-link[aria-current="page"] .nav-index { color: var(--green); }
.nav-index {
  font-family: var(--font-data);
  font-size: .7rem;
  font-weight: 700;
  color: var(--ink-muted);
  letter-spacing: .06em;
  width: 2.1em;
  transition: color .2s ease;
}
.nav-label { font-weight: 500; letter-spacing: .02em; }

.sidebar-footer {
  margin-top: auto;
  padding-top: 1.2rem;
  border-top: 1px solid var(--line-dim);
}
.live-status {
  display: flex;
  align-items: center;
  gap: .5rem;
  margin-bottom: .9rem;
  font-family: var(--font-data);
  font-size: .7rem;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--ink-muted);
}
.live-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--green);
  box-shadow: 0 0 12px rgba(57, 255, 20, .55);
}
.live-text { line-height: 1; }
.sidebar-note {
  margin-top: .8rem;
  font-size: .72rem;
  color: var(--ink-muted);
  letter-spacing: .04em;
}

/* 桌面端：固定侧边轨道 */
@media (min-width: 960px) {
  body { padding-left: var(--sidebar-w); }

  .site-header {
    position: fixed;
    top: 0;
    left: 0;
    bottom: 0;
    width: var(--sidebar-w);
  }
  .header-topbar { display: none; }

  .site-sidebar,
  .site-header[data-open] .site-sidebar {
    position: static;
    width: 100%;
    height: 100%;
    transform: none;
    visibility: visible;
    box-shadow: none;
    transition: none;
  }
  .drawer-scrim { display: none; }
}

/* ---------- 滚动进度与返回顶部 ---------- */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  z-index: calc(var(--header-z) + 50);
  pointer-events: none;
  background: rgba(176, 196, 222, .08);
}
.scroll-progress-bar {
  display: block;
  width: 0;
  height: 100%;
  background: linear-gradient(90deg, var(--blue), var(--green));
}

.back-top {
  display: inline-flex;
  align-items: center;
  gap: .5rem;
  position: fixed;
  right: 1.25rem;
  bottom: 1.25rem;
  z-index: calc(var(--header-z) + 40);
  padding: .65rem 1rem;
  border: 1px solid var(--line-blue);
  background: rgba(10, 15, 26, .92);
  color: var(--ink-body);
  font-family: var(--font-display);
  font-size: .8rem;
  font-weight: 700;
  transition: background-color .2s ease, border-color .2s ease, color .2s ease;
}
.back-top:hover {
  background: var(--blue);
  border-color: var(--blue);
  color: var(--ink-light);
}
.back-top-arrow { font-family: var(--font-data); font-size: .95rem; line-height: 1; }
.back-top-label { font-size: .78rem; }

/* ---------- 跳过链接 ---------- */
.skip-link {
  position: fixed;
  top: -120px;
  left: 1rem;
  z-index: calc(var(--header-z) + 60);
  display: inline-flex;
  align-items: center;
  padding: .7rem 1.2rem;
  background: var(--green);
  color: #05140B;
  font-family: var(--font-display);
  font-size: .8rem;
  font-weight: 900;
  line-height: 1;
  text-decoration: none;
  clip-path: polygon(8px 0, 100% 0, 100% calc(100% - 8px), calc(100% - 8px) 100%, 0 100%, 0 8px);
}
.skip-link:focus { top: 1rem; }

/* ---------- 页脚 ---------- */
.site-footer {
  position: relative;
  color: var(--ink-body);
  background:
    radial-gradient(circle at 85% 0%, rgba(0, 168, 255, .06), transparent 42%),
    linear-gradient(180deg, #0D1625, #090D16);
}
.site-footer::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--blue), var(--green) 55%, var(--orange));
  opacity: .9;
}

.footer-top {
  display: grid;
  gap: 2rem 2.5rem;
  padding-block: 3rem 2.5rem;
}
.footer-brand .footer-trust {
  margin-top: 1rem;
  max-width: 420px;
  font-size: .9rem;
  line-height: 1.75;
  color: var(--ink-muted);
}

.footer-col {
  position: relative;
  padding-left: .8rem;
}
.footer-col::before {
  content: "";
  position: absolute;
  left: 0;
  top: .2rem;
  bottom: .2rem;
  width: 2px;
  background: linear-gradient(180deg, rgba(0, 168, 255, .7), rgba(57, 255, 20, .3));
  opacity: .6;
}
.footer--nav { order: 2; }
.footer--contact { order: 3; }
.footer--legal { order: 4; }

.footer-heading {
  display: flex;
  align-items: center;
  gap: .6rem;
  margin-bottom: 1rem;
  font-size: .82rem;
  font-weight: 900;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--ink-light);
}
.footer-index {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: .15rem .42rem;
  border: 1px solid var(--line-green);
  background: rgba(57, 255, 20, .06);
  color: var(--green);
  font-family: var(--font-data);
  font-size: .68rem;
  font-weight: 700;
  line-height: 1.2;
}

.footer-links { display: flex; flex-direction: column; gap: .45rem; }
.footer-links a {
  font-size: .9rem;
  color: var(--ink-body);
  transition: color .2s ease, padding-left .2s ease;
}
.footer-links a:hover {
  color: var(--green);
  padding-left: .3rem;
}

.contact-list { gap: .6rem; }
.contact-list li {
  font-size: .82rem;
  line-height: 1.6;
  color: var(--ink-muted);
}
.contact-item {
  display: block;
  font-family: var(--font-data);
  font-size: .7rem;
  font-weight: 700;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--blue);
}

.footer-bottom {
  border-top: 1px solid var(--line-dim);
  background: rgba(0, 0, 0, .2);
}
.footer-bottom-inner {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: .4rem 1.5rem;
  padding-block: .95rem;
}
.footer-copy,
.footer-icp {
  margin: 0;
  font-family: var(--font-data);
  font-size: .74rem;
  letter-spacing: .04em;
  color: var(--ink-muted);
}

@media (min-width: 720px) {
  .footer-top { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-brand { grid-column: 1 / -1; }
}
@media (min-width: 1080px) {
  .footer-top { grid-template-columns: 1.5fr .9fr 1.25fr .8fr; }
  .footer-brand { grid-column: auto; }
}

/* ---------- 可访问性与动态偏好 ---------- */
:focus-visible {
  outline: 2px solid var(--green);
  outline-offset: 2px;
}

.sr-only {
  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;
  border: 0;
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *,
  *::before,
  *::after {
    transition-duration: .01ms !important;
    animation-duration: .01ms !important;
    animation-iteration-count: 1 !important;
  }
}