/* =========================================================
   OB体育主站 · /assets/site.css
   共享外壳：深空指挥台 + 侧边品牌轨道 + 印刷刻度语言
   ========================================================= */

/* ---------- 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, ul, ol, li, figure, blockquote, dl, dd { margin: 0; padding: 0; }
ul, ol { list-style: none; }
img, svg, video, canvas { display: block; max-width: 100%; }
a { color: inherit; text-decoration: none; }
button, input, select, textarea { font: inherit; color: inherit; background: none; border: 0; }
button { cursor: pointer; }
table { border-collapse: collapse; width: 100%; }

/* ---------- 2. 变量 ---------- */
:root {
  --ink: #06080C;
  --navy: #0C1219;
  --panel: #161E2A;
  --tick: #2A3646;
  --cyan: #00E5D0;
  --orange: #FF4B2B;
  --violet: #7B4DFF;
  --paper: #F3E7D3;
  --muted: #93A1B5;
  --teal-deep: #063B38;

  --rail-w: 274px;
  --bar-h: 64px;
  --shell: 1160px;

  --font-sans: "Source Han Sans SC", "Noto Sans SC", "PingFang SC", "Microsoft YaHei",
    system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --font-mono: "JetBrains Mono", "IBM Plex Mono", ui-monospace, SFMono-Regular,
    Menlo, Consolas, "Liberation Mono", monospace;

  --ease: cubic-bezier(.22, .68, .32, 1);
}

/* ---------- 3. 中文排版基础 ---------- */
body {
  min-height: 100vh;
  padding-top: var(--bar-h);
  background-color: var(--ink);
  background-image:
    radial-gradient(920px 520px at 82% -10%, rgba(123, 77, 255, .16), transparent 68%),
    radial-gradient(760px 440px at 2% 106%, rgba(0, 229, 208, .09), transparent 66%);
  background-repeat: no-repeat;
  color: var(--paper);
  font-family: var(--font-sans);
  font-size: 17px;
  font-weight: 400;
  line-height: 1.85;
  letter-spacing: .01em;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
}

h1, h2, h3, h4 {
  font-weight: 800;
  line-height: 1.2;
  letter-spacing: -.02em;
}
h1 { font-size: clamp(30px, 6vw, 56px); }
h2 { font-size: clamp(24px, 4vw, 34px); }
h3 { font-size: clamp(19px, 2.4vw, 26px); }
p { max-width: 38em; }

.mono, code, kbd, samp { font-family: var(--font-mono); letter-spacing: .5px; }

.data-num {
  font-family: var(--font-mono);
  font-weight: 700;
  letter-spacing: .5px;
  color: var(--cyan);
  font-size: clamp(30px, 6vw, 64px);
  line-height: 1;
}

.eyebrow {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .2em;
  color: var(--cyan);
  text-transform: uppercase;
  padding-bottom: 6px;
  border-bottom: 1px dashed var(--tick);
}

/* ---------- 4. 跳至主内容 ---------- */
.skip-link {
  position: fixed;
  top: -80px;
  left: 12px;
  z-index: 300;
  padding: 10px 18px;
  background: var(--cyan);
  color: var(--ink);
  font-weight: 700;
  font-size: 14px;
  border-radius: 2px;
  transition: top .18s var(--ease);
}
.skip-link:focus { top: 12px; }

/* ---------- 5. 全局焦点 ---------- */
:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
  border-radius: 1px;
}

/* ---------- 6. 头部 / 品牌轨道 ---------- */
.ob-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 120;
  padding: 0 18px;
  background-color: var(--navy);
  background-image: repeating-linear-gradient(180deg,
      rgba(42, 54, 70, .32) 0 1px, transparent 1px 44px);
  border-bottom: 1px solid var(--tick);
}

.rail-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  min-height: var(--bar-h);
}

.brand { display: flex; align-items: center; gap: 12px; }

.brand-mark {
  display: grid;
  place-items: center;
  flex: 0 0 42px;
  width: 42px;
  height: 42px;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-mono);
  font-size: 17px;
  font-weight: 700;
  letter-spacing: -.02em;
  box-shadow: 3px 3px 0 0 var(--orange);
}
.brand-mark--lg {
  flex: 0 0 54px;
  width: 54px;
  height: 54px;
  font-size: 20px;
  box-shadow: 4px 4px 0 0 var(--cyan);
}

.brand-text { display: flex; flex-direction: column; line-height: 1.25; }
.brand-name { font-size: 17px; font-weight: 800; color: var(--paper); letter-spacing: -.01em; }
.brand-sub {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--muted);
}

/* 移动导航按钮 */
.nav-toggle {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 8px 12px;
  border: 1px solid var(--tick);
  border-radius: 2px;
  color: var(--paper);
  font-size: 13px;
  letter-spacing: .08em;
  transition: border-color .18s var(--ease), color .18s var(--ease);
}
.nav-toggle:hover { border-color: var(--cyan); color: var(--cyan); }
.nav-toggle-bars { display: grid; gap: 4px; width: 18px; }
.nav-toggle-bars i {
  display: block;
  height: 2px;
  background: var(--cyan);
  transition: transform .2s var(--ease), opacity .2s var(--ease);
}
.ob-header[data-open] .nav-toggle-bars i:nth-child(1) { transform: translateY(6px) rotate(45deg); }
.ob-header[data-open] .nav-toggle-bars i:nth-child(2) { opacity: 0; }
.ob-header[data-open] .nav-toggle-bars i:nth-child(3) { transform: translateY(-6px) rotate(-45deg); }

/* 导航（移动端折叠 / 桌面端轨道） */
.site-nav {
  overflow: hidden;
  max-height: 0;
  opacity: 0;
  transition: max-height .3s var(--ease), opacity .22s var(--ease);
}
.ob-header[data-open] .site-nav {
  max-height: min(72vh, 560px);
  overflow-y: auto;
  opacity: 1;
  padding-bottom: 18px;
}

.nav-list { counter-reset: obnav; display: flex; flex-direction: column; gap: 2px; }
.nav-item { position: relative; }

.nav-link {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 11px 12px;
  color: var(--muted);
  font-size: 15px;
  font-weight: 600;
  border-left: 2px solid transparent;
  transition: color .18s var(--ease), background-color .18s var(--ease),
    border-color .18s var(--ease);
}
.nav-link::before {
  counter-increment: obnav;
  content: counter(obnav, decimal-leading-zero);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .06em;
  color: var(--tick);
  transition: color .18s var(--ease);
}
.nav-link:hover,
.nav-link:focus-visible {
  color: var(--paper);
  background: rgba(0, 229, 208, .07);
  border-left-color: var(--cyan);
}
.nav-link[aria-current="page"] {
  color: var(--ink);
  background: var(--paper);
  border-left-color: var(--orange);
}
.nav-link[aria-current="page"]::before { color: var(--orange); }

.nav-actions { display: flex; flex-direction: column; gap: 10px; margin-top: 18px; }

.nav-utility {
  margin-top: 14px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--muted);
  max-width: none;
}

/* 章节索引 + 轨道底部 */
.rail-index { display: flex; flex-direction: column; gap: 10px; padding-top: 8px; }
.rail-index[hidden] { display: none; }
.rail-index-title {
  font-family: var(--font-mono);
  font-size: 10.5px;
  letter-spacing: .2em;
  color: var(--muted);
}
.rail-index-list { display: flex; flex-direction: column; gap: 1px; }
.rail-index-btn {
  display: block;
  width: 100%;
  text-align: left;
  padding: 6px 0 6px 12px;
  border-left: 2px solid transparent;
  font-size: 12.5px;
  line-height: 1.5;
  color: var(--muted);
  transition: color .18s var(--ease), border-color .18s var(--ease);
}
.rail-index-btn:hover { color: var(--paper); }
.rail-index-btn.is-active { color: var(--cyan); border-left-color: var(--cyan); }

.rail-foot { display: flex; flex-direction: column; gap: 12px; padding-top: 14px; }

.version-chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  align-self: flex-start;
  padding: 5px 10px;
  border: 1px dashed var(--cyan);
  border-radius: 2px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--cyan);
}
.version-chip::before {
  content: "";
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--orange);
  box-shadow: 0 0 8px var(--orange);
  animation: obPulse 1.8s ease-in-out infinite;
}
@keyframes obPulse {
  0%, 100% { opacity: 1; transform: scale(1); }
  50% { opacity: .35; transform: scale(.78); }
}

.rail-note {
  padding-left: 10px;
  border-left: 2px solid var(--tick);
  font-size: 12px;
  line-height: 1.7;
  color: var(--muted);
  max-width: 34ch;
}

.to-top {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  align-self: flex-start;
  padding: 8px 13px;
  border: 1px solid var(--tick);
  border-radius: 2px;
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--muted);
  opacity: 0;
  pointer-events: none;
  transition: opacity .22s var(--ease), color .18s var(--ease), border-color .18s var(--ease);
}
.to-top.is-visible { opacity: 1; pointer-events: auto; }
.to-top:hover { color: var(--cyan); border-color: var(--cyan); }

.rail-progress {
  display: none;
  position: absolute;
  top: 0;
  right: -1px;
  width: 2px;
  height: 0;
  background: linear-gradient(180deg, var(--cyan), var(--violet));
}

/* ---------- 7. 按钮 ---------- */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 12px 18px;
  border: 1px solid var(--tick);
  border-radius: 2px;
  font-size: 15px;
  font-weight: 700;
  letter-spacing: .02em;
  color: var(--paper);
  background: transparent;
  transition: transform .16s var(--ease), background-color .18s var(--ease),
    color .18s var(--ease), border-color .18s var(--ease), box-shadow .18s var(--ease);
}
.btn:hover { transform: translate(-1px, -1px); }
.btn-primary {
  background: var(--orange);
  border-color: var(--orange);
  color: #0A0F16;
  box-shadow: 4px 4px 0 0 rgba(123, 77, 255, .55);
}
.btn-primary:hover { background: #FF6245; }
.btn-ghost { border-color: var(--cyan); color: var(--cyan); }
.btn-ghost:hover { background: rgba(0, 229, 208, .12); }

/* ---------- 8. 页脚 ---------- */
.ob-footer {
  position: relative;
  background-color: var(--navy);
  background-image: repeating-linear-gradient(90deg,
      rgba(42, 54, 70, .5) 0 1px, transparent 1px 46px);
  border-top: 1px solid var(--tick);
  padding: 54px 20px 34px;
}
.footer-ticks {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 8px;
  background: repeating-linear-gradient(90deg, var(--tick) 0 1px, transparent 1px 24px);
  opacity: .85;
  pointer-events: none;
}
.footer-inner {
  max-width: var(--shell);
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr;
  gap: 34px 28px;
}
.footer-brand-name {
  margin-top: 16px;
  font-size: 19px;
  font-weight: 800;
  letter-spacing: -.01em;
  color: var(--paper);
}
.footer-brand-line {
  margin-top: 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--muted);
  max-width: none;
}
.footer-col-title {
  margin-bottom: 14px;
  padding-bottom: 8px;
  border-bottom: 1px dashed var(--tick);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: .2em;
  color: var(--cyan);
}
.footer-links { display: flex; flex-direction: column; gap: 9px; }
.footer-link {
  display: inline-block;
  font-size: 14.5px;
  color: var(--paper);
  opacity: .82;
  transition: color .18s var(--ease), opacity .18s var(--ease), transform .18s var(--ease);
}
.footer-link:hover { color: var(--cyan); opacity: 1; transform: translateX(3px); }

.footer-service { padding-top: 26px; border-top: 1px solid var(--tick); }
.footer-service-list { display: grid; grid-template-columns: 1fr; gap: 14px; }
.footer-service-item {
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
  letter-spacing: .02em;
}
.footer-service-item strong {
  display: block;
  margin-bottom: 4px;
  font-family: var(--font-mono);
  font-size: 10.5px;
  font-weight: 700;
  letter-spacing: .18em;
  color: var(--paper);
}
.footer-service-note { display: block; margin-top: 4px; font-size: 12px; color: var(--muted); opacity: .8; }

.footer-legal {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 22px;
  padding-top: 20px;
  border-top: 1px solid var(--tick);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .05em;
  color: var(--muted);
}

/* ---------- 9. 通用容器 / 网格 / 章节 ---------- */
.container { width: 100%; max-width: var(--shell); margin: 0 auto; padding: 0 20px; }
.container--narrow { max-width: 760px; }

.section { padding: 64px 0; }
.section--wide { background: var(--navy); border-top: 1px solid var(--tick); border-bottom: 1px solid var(--tick); }
.section--narrow { padding: 40px 0; }

.grid { display: grid; gap: 24px; grid-template-columns: 1fr; }
@media (min-width: 720px) {
  .grid--2 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .grid--3 { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (min-width: 1024px) {
  .grid--12 { grid-template-columns: repeat(12, minmax(0, 1fr)); }
  .grid--3 { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}
.col-4 { grid-column: span 4; }
.col-5 { grid-column: span 5; }
.col-6 { grid-column: span 6; }
.col-7 { grid-column: span 7; }
.col-8 { grid-column: span 8; }
.col-12 { grid-column: 1 / -1; }

/* ---------- 10. 面包屑 ---------- */
.breadcrumb {
  padding: 20px 0 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--muted);
}
.breadcrumb-list { display: flex; flex-wrap: wrap; gap: 8px; align-items: center; }
.breadcrumb-item { display: inline-flex; align-items: center; gap: 8px; }
.breadcrumb-item + .breadcrumb-item::before { content: "/"; color: var(--tick); }
.breadcrumb-link { color: var(--muted); transition: color .18s var(--ease); }
.breadcrumb-link:hover { color: var(--cyan); }
.breadcrumb-current { color: var(--paper); }

/* ---------- 11. 图片容器基础件 ---------- */
.frame {
  position: relative;
  border: 1px solid var(--tick);
  background: linear-gradient(160deg, var(--panel), #0A0F16);
  overflow: hidden;
}
.frame::before,
.frame::after {
  content: "";
  position: absolute;
  width: 14px;
  height: 14px;
  pointer-events: none;
  z-index: 2;
}
.frame::before { top: -1px; left: -1px; border-top: 2px solid var(--cyan); border-left: 2px solid var(--cyan); }
.frame::after { bottom: -1px; right: -1px; border-bottom: 2px solid var(--orange); border-right: 2px solid var(--orange); }

.frame-media {
  position: relative;
  width: 100%;
  aspect-ratio: 16 / 9;
  overflow: hidden;
  background: linear-gradient(140deg, #101825, #06080C 65%);
}
.frame-media--4x3 { aspect-ratio: 4 / 3; }
.frame-media--1x1 { aspect-ratio: 1 / 1; }
.frame-media--21x9 { aspect-ratio: 21 / 9; }
.frame-media img { width: 100%; height: 100%; object-fit: cover; }

.frame-tag {
  position: absolute;
  top: 10px;
  left: 10px;
  z-index: 3;
  padding: 4px 9px;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .1em;
}
.frame-caption {
  padding: 10px 12px;
  border-top: 1px dashed var(--tick);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: .05em;
  color: var(--muted);
}

/* ---------- 12. 显现动效 ---------- */
[data-reveal] {
  opacity: 0;
  transform: translateY(18px);
  transition: opacity .5s var(--ease), transform .5s var(--ease);
}
[data-reveal].is-in { opacity: 1; transform: none; }

/* ---------- 13. 平板 / 桌面：侧边品牌轨道 ---------- */
@media (min-width: 1024px) {
  body { padding-top: 0; padding-left: var(--rail-w); }

  .ob-header {
    inset: 0 auto 0 0;
    width: var(--rail-w);
    display: flex;
    flex-direction: column;
    gap: 20px;
    padding: 28px 24px 22px;
    border-right: 1px solid var(--tick);
    border-bottom: 0;
    overflow-y: auto;
    scrollbar-width: thin;
  }
  .ob-header::-webkit-scrollbar { width: 6px; }
  .ob-header::-webkit-scrollbar-thumb { background: var(--tick); }

  .rail-top { display: block; min-height: 0; }
  .nav-toggle { display: none; }

  .site-nav {
    max-height: none;
    overflow: visible;
    opacity: 1;
    transition: none;
  }

  .rail-index { margin-top: auto; }
  .rail-index[hidden] + .rail-foot { margin-top: auto; }

  .rail-progress { display: block; }

  .section { padding: 88px 0; }
  .section--narrow { padding: 52px 0; }
  .container { padding: 0 32px; }
}

@media (min-width: 720px) {
  .footer-inner { grid-template-columns: repeat(2, minmax(0, 1fr)); }
  .footer-brand { grid-column: 1 / -1; }
  .footer-service { grid-column: 1 / -1; }
  .footer-legal { grid-column: 1 / -1; }
  .footer-service-list { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (min-width: 900px) {
  .footer-service-list { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}
@media (min-width: 1080px) {
  .footer-inner { grid-template-columns: 1.25fr 1fr 1fr; }
  .footer-brand { grid-column: auto; }
  .footer-service { grid-column: 1 / -1; }
  .footer-legal { grid-column: 1 / -1; }
}

/* ---------- 14. 降低动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: .001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: .001ms !important;
  }
  [data-reveal] { opacity: 1; transform: none; }
  .site-nav { transition: none; }
}