/* ===== B体育免费CN · site.css ===== */

*,
*::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, figure, blockquote {
  margin: 0;
}

ul, ol {
  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;
}

:root {
  --ink: #06120F;
  --panel: #0C221C;
  --line: #17483A;
  --mint: #38F2C0;
  --ice: #7CE7FF;
  --flame: #FF5A36;
  --away: #5B7CFA;
  --home: #A78BFA;
  --fog: #E8F3EE;
  --mute: #9BB3AA;

  --rail-w: 88px;
  --topbar-h: 56px;
  --shell-max: 1240px;

  --font-display: 'Barlow Condensed', 'Roboto Condensed', 'Noto Sans SC Condensed', system-ui, sans-serif;
  --font-head: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', system-ui, sans-serif;
  --font-body: 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', system-ui, sans-serif;
  --font-mono: 'JetBrains Mono', 'IBM Plex Mono', ui-monospace, SFMono-Regular, Menlo, monospace;

  --ease: cubic-bezier(.2, .7, .3, 1);
}

body {
  background: var(--ink);
  color: var(--fog);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
  padding-top: var(--topbar-h);
  padding-left: var(--rail-w);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

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

[data-section] {
  scroll-margin-top: calc(var(--topbar-h) + 24px);
}

/* ---------- 基础排版 ---------- */

h1, h2, h3, h4 {
  font-family: var(--font-head);
  font-weight: 700;
  letter-spacing: -0.01em;
  line-height: 1.24;
}

h1 { font-size: clamp(30px, 4.4vw, 44px); }
h2 { font-size: clamp(24px, 3vw, 28px); }
h3 { font-size: 20px; }
h4 { font-size: 16px; }

p { max-width: 38em; }

.skip-link {
  position: fixed;
  top: 8px;
  left: 8px;
  z-index: 300;
  padding: 10px 18px;
  background: var(--mint);
  color: var(--ink);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  border-radius: 2px;
  transform: translateY(-180%);
  transition: transform .2s var(--ease);
}

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

/* ---------- 通用容器与组件 ---------- */

.shell {
  width: 100%;
  max-width: var(--shell-max);
  margin: 0 auto;
  padding: 0 clamp(20px, 4vw, 48px);
}

.shell--narrow {
  max-width: 820px;
}

.section {
  padding: clamp(48px, 7vw, 96px) 0;
}

.section--light {
  background: var(--fog);
  color: var(--ink);
}

.section__title {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: clamp(24px, 3vw, 28px);
  letter-spacing: -0.01em;
  line-height: 1.25;
}

.lede {
  max-width: 36em;
  font-size: clamp(15px, 1.4vw, 17px);
  line-height: 1.8;
  color: var(--mute);
}

.section--light .lede {
  color: #3F5A52;
}

.eyebrow {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--mint);
}

.hairline {
  height: 1px;
  border: 0;
  background: var(--line);
}

.cut {
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 24px), calc(100% - 24px) 100%, 0 100%);
}

.prose {
  max-width: 38em;
  font-size: 16px;
  line-height: 1.75;
  color: var(--fog);
}

.prose p + p { margin-top: 1.1em; }
.prose h2, .prose h3 { margin-top: 2em; margin-bottom: 0.6em; }
.prose p { max-width: none; }

.prose a {
  color: var(--ice);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-thickness: 1px;
}

.prose li {
  position: relative;
  padding-left: 18px;
  margin-bottom: 0.5em;
}

.prose li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.78em;
  width: 7px;
  height: 1px;
  background: var(--mint);
}

.prose--light { color: var(--ink); }
.prose--light a { color: #0B5F4B; text-decoration-color: var(--mint); }

.btn {
  --btn-bg: var(--mint);
  position: relative;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 13px 26px 13px 22px;
  background: linear-gradient(315deg, transparent 10px, var(--btn-bg) 0);
  color: var(--ink);
  font-family: var(--font-head);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.02em;
  line-height: 1.2;
  transition: color .2s var(--ease), transform .2s var(--ease);
}

.btn:hover { --btn-bg: var(--ice); }
.btn:active { transform: translateY(1px); }

.btn--ghost {
  --btn-bg: transparent;
  color: var(--fog);
  border: 1px solid var(--line);
  background: none;
}

.btn--ghost:hover {
  border-color: var(--mint);
  color: var(--mint);
  background: rgba(56, 242, 192, 0.07);
}

.btn--flame { --btn-bg: var(--flame); color: #120604; }
.btn--flame:hover { --btn-bg: #FF7455; }

.breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--mute);
}

.breadcrumb__link { color: var(--mute); }
.breadcrumb__link:hover { color: var(--mint); }
.breadcrumb__sep { color: var(--line); }
.breadcrumb__current { color: var(--fog); }

.grid {
  display: grid;
  gap: clamp(16px, 2.4vw, 28px);
}

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

.split {
  display: grid;
  grid-template-columns: 5fr 5fr;
  gap: clamp(20px, 4vw, 56px);
  align-items: start;
}

.media-frame {
  position: relative;
  overflow: hidden;
  aspect-ratio: 16 / 10;
  background: var(--panel);
  border-radius: 2px;
}

.media-frame::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(160deg, rgba(6, 18, 15, 0.12) 0%, rgba(6, 18, 15, 0.78) 100%);
  pointer-events: none;
}

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

.media-frame--wide { aspect-ratio: 21 / 9; }
.media-frame--tall { aspect-ratio: 3 / 4; }

.media-frame--cut {
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 32px), calc(100% - 32px) 100%, 0 100%);
}

.stat {
  display: flex;
  align-items: baseline;
  gap: 6px;
  font-family: var(--font-display);
}

.stat__num {
  font-size: clamp(44px, 6vw, 88px);
  line-height: 0.92;
  font-weight: 700;
  letter-spacing: -0.01em;
}

.stat__unit {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--mute);
}

.tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  padding: 4px 9px;
  border: 1px solid var(--line);
  border-radius: 2px;
  background: rgba(56, 242, 192, 0.05);
  color: var(--mint);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  line-height: 1.4;
}

.tag--flame {
  color: var(--flame);
  border-color: rgba(255, 90, 54, 0.42);
  background: rgba(255, 90, 54, 0.07);
}

/* ---------- 头部：侧边轨道 ---------- */

.site-header {
  position: relative;
  z-index: 120;
}

.rail {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  width: var(--rail-w);
  z-index: 130;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 16px 0 14px;
  background: linear-gradient(180deg, #08170F 0%, var(--ink) 42%, #071411 100%);
  border-right: 1px solid var(--line);
  overflow-y: auto;
  overflow-x: hidden;
  scrollbar-width: thin;
  scrollbar-color: var(--line) transparent;
}

.rail::-webkit-scrollbar { width: 4px; }
.rail::-webkit-scrollbar-thumb { background: var(--line); border-radius: 2px; }

.rail__brand {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  width: 100%;
  padding: 6px 0 14px;
  border-bottom: 1px solid var(--line);
}

.rail__mark {
  display: grid;
  place-items: center;
  width: 34px;
  height: 34px;
  background: var(--mint);
  color: var(--ink);
  font-family: var(--font-display);
  font-size: 22px;
  font-weight: 700;
  line-height: 1;
  clip-path: polygon(0 0, 100% 0, 100% 72%, 72% 100%, 0 100%);
}

.rail__name {
  writing-mode: vertical-rl;
  text-orientation: upright;
  font-size: 11px;
  letter-spacing: 0.28em;
  color: var(--mute);
}

.rail__nav {
  flex: 1 0 auto;
  width: 100%;
  padding: 14px 0;
}

.nav-list {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.nav-item { display: block; }

.nav-link {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  padding: 12px 4px;
  color: var(--mute);
  transition: color .2s var(--ease), background-color .2s var(--ease);
}

.nav-link::before {
  content: "";
  position: absolute;
  left: 0;
  top: 14px;
  bottom: 14px;
  width: 2px;
  background: var(--mint);
  transform: scaleY(0);
  transform-origin: top center;
  transition: transform .24s var(--ease);
}

.nav-link__idx {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--mute);
  opacity: 0.65;
  transition: color .2s var(--ease), opacity .2s var(--ease);
}

.nav-link__label {
  writing-mode: vertical-rl;
  text-orientation: upright;
  font-size: 11px;
  letter-spacing: 0.2em;
  line-height: 1.2;
}

.nav-link:hover,
.nav-link:focus-visible {
  color: var(--fog);
  background: rgba(56, 242, 192, 0.06);
}

.nav-link:hover .nav-link__idx,
.nav-link:focus-visible .nav-link__idx {
  color: var(--ice);
  opacity: 1;
}

.nav-link[aria-current="page"] { color: var(--fog); }

.nav-link[aria-current="page"] .nav-link__idx {
  color: var(--mint);
  opacity: 1;
}

.nav-link[aria-current="page"]::before { transform: scaleY(1); }

.rail__scan {
  width: 100%;
  display: flex;
  justify-content: center;
  padding: 14px 0 4px;
  border-top: 1px solid var(--line);
}

.rail__scan-bar {
  position: relative;
  display: block;
  width: 2px;
  height: 72px;
  background: var(--line);
  border-radius: 1px;
  overflow: hidden;
}

.rail__scan-dot {
  position: absolute;
  top: 0;
  left: 0;
  width: 2px;
  height: 18px;
  background: linear-gradient(180deg, var(--mint), var(--ice));
  border-radius: 1px;
  transition: top .12s linear;
}

/* ---------- 头部：顶栏 ---------- */

.topbar {
  position: fixed;
  top: 0;
  left: var(--rail-w);
  right: 0;
  z-index: 110;
  display: flex;
  align-items: center;
  gap: 20px;
  height: var(--topbar-h);
  padding: 0 24px;
  background: #071512;
  border-bottom: 1px solid var(--line);
}

.topbar__id {
  display: flex;
  align-items: baseline;
  gap: 12px;
  min-width: 0;
}

.topbar__brand {
  font-family: var(--font-head);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--fog);
  white-space: nowrap;
}

.topbar__sub {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--mute);
  white-space: nowrap;
}

.topbar__meta {
  display: flex;
  align-items: center;
  gap: 8px;
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--mute);
  white-space: nowrap;
}

.topbar__dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--mint);
  box-shadow: 0 0 0 3px rgba(56, 242, 192, 0.14);
}

.nav-toggle {
  display: none;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border: 1px solid var(--line);
  border-radius: 2px;
  color: var(--fog);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  line-height: 1.2;
}

.nav-toggle__bars {
  display: flex;
  flex-direction: column;
  gap: 4px;
  width: 16px;
}

.nav-toggle__bars i {
  display: block;
  height: 1.5px;
  width: 100%;
  background: currentColor;
  transition: transform .24s var(--ease), opacity .24s var(--ease);
}

.site-header[data-open="true"] .nav-toggle__bars i:first-child {
  transform: translateY(2.75px) rotate(45deg);
}

.site-header[data-open="true"] .nav-toggle__bars i:last-child {
  transform: translateY(-2.75px) rotate(-45deg);
}

.nav-toggle__text { white-space: nowrap; }

.read-progress {
  position: absolute;
  left: 0;
  bottom: -1px;
  display: block;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--mint) 0%, var(--ice) 55%, var(--flame) 100%);
  z-index: 2;
  transition: width .1s linear;
}

.nav-scrim {
  position: fixed;
  inset: 0;
  z-index: 115;
  background: rgba(4, 12, 10, 0.72);
  opacity: 0;
  visibility: hidden;
  transition: opacity .28s var(--ease), visibility .28s var(--ease);
}

.site-header[data-open="true"] .nav-scrim {
  opacity: 1;
  visibility: visible;
}

/* ---------- 移动底部快捷条 ---------- */

.dock { display: none; }

.dock__link {
  display: flex;
  align-items: center;
  justify-content: center;
  min-height: 52px;
  background: var(--ink);
  color: var(--fog);
  font-family: var(--font-head);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.02em;
}

.dock__link--alt { color: var(--mint); }

/* ---------- 页脚 ---------- */

.site-footer {
  position: relative;
  margin-top: clamp(40px, 6vw, 80px);
  padding: clamp(36px, 5vw, 64px) 0 0;
  background: var(--panel);
  border-top: 1px solid var(--line);
  overflow: hidden;
}

.site-footer::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--mint) 0%, var(--ice) 42%, var(--flame) 100%);
  opacity: 0.85;
}

.footer__inner {
  width: 100%;
  max-width: var(--shell-max);
  margin: 0 auto;
  padding: 0 clamp(20px, 4vw, 48px);
}

.footer__top {
  display: grid;
  grid-template-columns: 1.3fr 1fr auto;
  gap: clamp(24px, 4vw, 48px);
  padding-bottom: 28px;
  border-bottom: 1px solid var(--line);
}

.footer__brand { min-width: 0; }

.footer__mark {
  display: inline-block;
  font-family: var(--font-head);
  font-size: 18px;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--fog);
}

.footer__mark:hover { color: var(--mint); }

.footer__tagline {
  margin-top: 8px;
  max-width: 24em;
  font-size: 13px;
  line-height: 1.7;
  color: var(--mute);
}

.footer__nav { min-width: 0; }

.footer__list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px 24px;
}

.footer__link {
  display: inline-block;
  font-size: 13px;
  line-height: 1.7;
  color: var(--mute);
  transition: color .2s var(--ease);
}

.footer__link:hover { color: var(--mint); }

.footer__legal {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.footer__link--legal {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
}

.footer__contact {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 14px clamp(20px, 3vw, 40px);
  padding: 26px 0;
  border-bottom: 1px solid var(--line);
}

.footer__field {
  display: flex;
  flex-direction: column;
  gap: 4px;
  min-width: 0;
  max-width: none;
}

.footer__key {
  font-family: var(--font-mono);
  font-size: 10px;
  letter-spacing: 0.18em;
  color: var(--line);
  color: #4C7F6D;
}

.footer__val {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.02em;
  line-height: 1.6;
  color: var(--fog);
  word-break: break-word;
}

.footer__note {
  grid-column: 1 / -1;
  max-width: 52em;
  font-size: 12px;
  line-height: 1.8;
  color: var(--mute);
}

.footer__base {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 14px 24px;
  padding: 20px 0 28px;
}

.footer__copy,
.footer__icp {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--mute);
  max-width: none;
}

.footer__top-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 14px;
  border: 1px solid var(--line);
  border-radius: 2px;
  color: var(--mute);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  line-height: 1.2;
  transition: color .2s var(--ease), border-color .2s var(--ease);
}

.footer__top-btn:hover {
  color: var(--mint);
  border-color: var(--mint);
}

/* ---------- 平板与移动 ---------- */

@media (max-width: 1023px) {
  body {
    padding-left: 0;
    padding-bottom: 56px;
  }

  body[data-nav-open="true"] { overflow: hidden; }

  .rail {
    top: 0;
    bottom: 0;
    left: 0;
    width: min(86vw, 340px);
    align-items: stretch;
    padding: 20px 20px 28px;
    border-right: 1px solid var(--line);
    transform: translateX(-100%);
    transition: transform .32s var(--ease);
  }

  .site-header[data-open="true"] .rail { transform: translateX(0); }

  .rail__brand {
    flex-direction: row;
    align-items: center;
    gap: 12px;
    padding: 0 0 8px;
    border-bottom: 1px solid var(--line);
  }

  .rail__mark {
    width: 30px;
    height: 30px;
    font-size: 19px;
  }

  .rail__name {
    writing-mode: horizontal-tb;
    font-size: 12px;
    letter-spacing: 0.2em;
    color: var(--fog);
  }

  .rail__nav {
    flex: 1 1 auto;
    padding: 16px 0;
    overflow-y: auto;
  }

  .nav-list { gap: 0; }

  .nav-link {
    flex-direction: row;
    align-items: center;
    gap: 14px;
    padding: 14px 8px;
    border-bottom: 1px solid rgba(23, 72, 58, 0.62);
  }

  .nav-link::before {
    top: 8px;
    bottom: 8px;
  }

  .nav-link__idx {
    width: 22px;
    font-size: 11px;
  }

  .nav-link__label {
    writing-mode: horizontal-tb;
    font-size: 15px;
    letter-spacing: 0.02em;
  }

  .rail__scan { display: none; }

  .topbar {
    left: 0;
    gap: 12px;
    padding: 0 16px;
  }

  .topbar__sub { display: none; }
  .topbar__meta { display: none; }
  .topbar__brand { font-size: 14px; }

  .nav-toggle {
    display: inline-flex;
    margin-left: auto;
  }

  .dock {
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    z-index: 118;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1px;
    background: var(--line);
    border-top: 1px solid var(--line);
    padding-bottom: env(safe-area-inset-bottom, 0px);
  }

  .dock__link:hover,
  .dock__link:focus-visible { background: #0A1C17; }

  .footer__top {
    grid-template-columns: 1fr;
    gap: 24px;
  }

  .footer__legal {
    flex-direction: row;
    flex-wrap: wrap;
    gap: 18px;
  }

  .footer__contact {
    grid-template-columns: 1fr;
    gap: 14px;
  }
}

@media (min-width: 1024px) {
  .nav-scrim { display: none; }
  .site-header[data-open="true"] .rail { transform: none; }
}

@media (min-width: 1024px) and (max-height: 860px) {
  .rail { padding: 10px 0; }
  .rail__brand { padding-bottom: 10px; }
  .nav-link { padding: 9px 4px; gap: 6px; }
  .nav-link__label { font-size: 10.5px; letter-spacing: 0.16em; }
  .rail__scan-bar { height: 52px; }
}

@media (max-width: 767px) {
  .grid--2 { grid-template-columns: 1fr; }
  .split { grid-template-columns: 1fr; }
  .footer__list { grid-template-columns: 1fr 1fr; gap: 8px 16px; }
  .footer__base { flex-direction: column; align-items: flex-start; gap: 12px; }
  .prose { font-size: 15px; line-height: 1.8; }
  body { font-size: 15px; }
}

@media (max-width: 400px) {
  .topbar__brand { font-size: 13px; }
  .nav-toggle__text { display: none; }
}

@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;
    scroll-behavior: auto !important;
  }
}