/* ==========================================================================
   乐动在线 /assets/site.css — 共享外壳与基础组件
   深石墨 + 冷银 + 单一琥珀橙锚点；框架式导航构成页面左边框
   ========================================================================== */

:root{
  --c-amber:#FF7A00;
  --c-amber-hi:#FFB067;
  --c-graphite:#1E1E1E;
  --c-panel:#2A2A2A;
  --c-silver:#D9DEE3;
  --c-grid:#3B4A57;
  --c-green:#2FBF71;
  --c-red:#E5484D;
  --c-cream:#F5F3EF;
  --c-ink:#0F0F0F;
  --c-muted:#8E98A2;
  --c-line:rgba(59,74,87,.75);

  --font-display:"Oswald","Arial Narrow","Helvetica Neue",system-ui,"PingFang SC","Microsoft YaHei",sans-serif;
  --font-body:"Inter",system-ui,-apple-system,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  --font-serif:"Noto Serif SC","Songti SC","Source Han Serif SC",Georgia,serif;
  --font-mono:"JetBrains Mono","SFMono-Regular",Consolas,"Liberation Mono",monospace;

  --rail-w:248px;
  --topbar-h:44px;
  --wrap:1180px;

  --sp-1:8px; --sp-2:14px; --sp-3:20px; --sp-4:28px; --sp-5:44px; --sp-6:72px; --sp-7:120px;
}

*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body,
h1,h2,h3,h4,h5,p,ul,ol,dl,dd,figure,blockquote{margin:0}
ul,ol{padding:0;list-style:none}
a{color:inherit;text-decoration:none}
button{font:inherit;color:inherit;background:none;border:0;cursor:pointer}
img,svg{display:block;max-width:100%}
table{border-collapse:collapse;width:100%}
::selection{background:var(--c-amber);color:#141414}

body{
  font-family:var(--font-body);
  font-size:16px;
  line-height:1.75;
  background:var(--c-graphite);
  color:var(--c-silver);
  -webkit-font-smoothing:antialiased;
  min-height:100vh;
}

:focus-visible{outline:2px solid var(--c-amber);outline-offset:3px}

#main-content{padding-top:var(--topbar-h)}
[data-chapter]{scroll-margin-top:calc(var(--topbar-h) + 24px)}

.wrap{width:min(100% - 40px,var(--wrap));margin-inline:auto}
.mono{font-family:var(--font-mono);letter-spacing:.01em}
.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0}
.divider{height:1px;background:var(--c-grid);border:0}

/* ---------------------------------------------------------- 跳转链接 */
.skip-link{
  position:fixed;top:8px;left:8px;z-index:200;
  transform:translateY(-180%);
  background:var(--c-amber);color:#141414;
  font-family:var(--font-mono);font-size:13px;font-weight:600;
  padding:12px 18px;border-radius:2px;
  transition:transform .2s ease;
}
.skip-link:focus{transform:none}

/* ---------------------------------------------------------- 头部外壳 */
.site-header{position:relative;z-index:80}

.topbar{
  position:fixed;top:0;left:0;right:0;z-index:90;
  height:var(--topbar-h);
  display:flex;align-items:center;gap:12px;
  padding:0 clamp(14px,3vw,28px);
  background:rgba(24,24,24,.96);
  border-bottom:1px solid var(--c-grid);
  color:var(--c-silver);
}
.topbar__meta{
  display:flex;align-items:center;gap:8px;
  flex:1 1 auto;min-width:0;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.06em;
  color:#A9B2BA;
  white-space:nowrap;overflow:hidden;text-overflow:ellipsis;
}
.topbar__actions{display:flex;align-items:center;gap:10px;flex:0 0 auto;margin-left:auto}
.topbar__cta{display:none}
.topbar__track{
  position:absolute;left:0;right:0;bottom:-1px;height:2px;
  background:rgba(217,222,227,.12);
}
.topbar__progress{display:block;height:100%;width:0;background:var(--c-amber);transition:width .12s linear}

.nav-toggle{
  display:inline-flex;align-items:center;gap:10px;
  height:30px;padding:0 12px;
  border:1px solid var(--c-grid);border-radius:2px;
  color:var(--c-silver);
  font-family:var(--font-mono);font-size:11px;font-weight:600;
  letter-spacing:.12em;text-transform:uppercase;
  transition:color .18s ease,border-color .18s ease;
}
.nav-toggle::before{
  content:"";width:14px;height:2px;background:currentColor;
  box-shadow:0 5px 0 currentColor,0 -5px 0 currentColor;
}
.nav-toggle__label{line-height:1}
.nav-toggle:hover{border-color:var(--c-amber);color:var(--c-amber)}
.nav-toggle[aria-expanded="true"]{color:var(--c-amber);border-color:var(--c-amber)}

/* ---------------------------------------------------------- 左侧导航轨 */
.rail{
  position:fixed;z-index:80;
  top:var(--topbar-h);left:0;bottom:0;
  width:min(300px,84vw);
  display:flex;flex-direction:column;
  overflow-y:auto;overscroll-behavior:contain;
  background:var(--c-graphite);
  border-right:1px solid var(--c-grid);
  transform:translateX(-100%);
  transition:transform .24s ease;
  box-shadow:12px 0 28px rgba(0,0,0,.5);
}
.rail[data-open]{transform:none}
.rail::before{
  content:"";position:absolute;inset:0;pointer-events:none;
  background-image:
    linear-gradient(rgba(59,74,87,.06) 1px,transparent 1px),
    linear-gradient(90deg,rgba(59,74,87,.06) 1px,transparent 1px);
  background-size:24px 24px;
}
.rail__brand{
  position:relative;display:block;
  padding:22px 20px 18px;
  border-bottom:1px solid var(--c-grid);
}
.rail__mark{
  display:block;
  font-family:var(--font-display);font-weight:600;
  font-size:26px;line-height:1.05;letter-spacing:.04em;
  color:#fff;text-transform:uppercase;
  transition:color .18s ease;
}
.rail__brand:hover .rail__mark{color:var(--c-amber)}
.rail__tag{
  display:block;margin-top:9px;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.16em;
  color:var(--c-amber);text-transform:uppercase;
}
.rail__tag::before{
  content:"";display:inline-block;width:18px;height:1px;
  background:var(--c-amber);vertical-align:middle;margin-right:8px;
}
.rail__nav{position:relative;flex:1 1 auto;padding:16px 0 10px}
.rail__list{display:flex;flex-direction:column}
.rail__item{display:block}
.rail__link{
  position:relative;display:flex;align-items:baseline;gap:10px;
  padding:11px 20px;
  border-left:2px solid transparent;
  color:#B8C0C8;font-size:14px;letter-spacing:.02em;
  transition:color .18s ease,transform .18s ease,border-color .18s ease;
}
.rail__num{
  font-family:var(--font-mono);font-size:11px;letter-spacing:.06em;
  color:var(--c-grid);transition:color .18s ease;
}
.rail__label{letter-spacing:.02em}
.rail__link:hover{color:#fff}
.rail__link:hover .rail__num{color:var(--c-amber-hi)}
.rail__link[aria-current="page"]{
  color:var(--c-amber);
  border-left-color:var(--c-amber);
  transform:translateX(-4px);
}
.rail__link[aria-current="page"] .rail__num{color:var(--c-amber)}
.rail__link[aria-current="page"]::after{
  content:"";position:absolute;right:14px;top:50%;
  width:14px;height:1px;background:var(--c-amber);
}
.rail__foot{
  position:relative;margin-top:auto;
  display:flex;flex-direction:column;gap:16px;
  padding:18px 20px 24px;
  border-top:1px solid var(--c-grid);
}
.rail__legend{display:flex;flex-direction:column;gap:8px}
.legend-item{
  display:flex;align-items:center;gap:8px;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.06em;
  color:var(--c-muted);
}
.rail__actions{display:flex;flex-direction:column;gap:10px}

.nav-scrim{
  position:fixed;inset:0;z-index:60;
  background:rgba(12,12,12,.68);
  opacity:0;visibility:hidden;
  transition:opacity .2s ease,visibility .2s ease;
}
.rail[data-open]~.nav-scrim{opacity:1;visibility:visible}

@media (max-width:1023.98px){
  html.is-nav-open{overflow:hidden}
}

/* ---------------------------------------------------------- 状态点 */
.dot{width:8px;height:8px;border-radius:50%;flex:0 0 auto;display:inline-block;background:var(--c-grid)}
.dot--green{background:var(--c-green);box-shadow:0 0 0 3px rgba(47,191,113,.16)}
.dot--amber{background:var(--c-amber);box-shadow:0 0 0 3px rgba(255,122,0,.16)}
.dot--red{background:var(--c-red);box-shadow:0 0 0 3px rgba(229,72,77,.16)}
.dot--grid{background:transparent;box-shadow:inset 0 0 0 1px var(--c-grid)}

/* ---------------------------------------------------------- 按钮 */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  padding:12px 18px;border:1px solid transparent;border-radius:2px;
  font-family:var(--font-display);font-size:14px;font-weight:600;
  letter-spacing:.08em;text-transform:uppercase;line-height:1.2;
  transition:background-color .18s ease,color .18s ease,border-color .18s ease;
}
.btn--primary{background:var(--c-amber);color:#141414;border-color:var(--c-amber)}
.btn--primary:hover{background:var(--c-amber-hi);border-color:var(--c-amber-hi);color:#141414}
.btn--ghost{background:transparent;color:var(--c-silver);border-color:var(--c-grid)}
.btn--ghost:hover{color:var(--c-amber);border-color:var(--c-amber)}
.btn--sm{padding:7px 12px;font-size:11px;letter-spacing:.12em}
.btn--block{width:100%}

/* ---------------------------------------------------------- 页脚 */
.site-footer{
  position:relative;overflow:hidden;
  background:var(--c-graphite);color:var(--c-silver);
  border-top:1px solid var(--c-grid);
}
.site-footer::before{
  content:"";position:absolute;top:0;left:0;z-index:2;
  width:140px;height:3px;background:var(--c-amber);
}
.site-footer::after{
  content:"";position:absolute;inset:0;pointer-events:none;
  background-image:
    linear-gradient(rgba(59,74,87,.06) 1px,transparent 1px),
    linear-gradient(90deg,rgba(59,74,87,.06) 1px,transparent 1px);
  background-size:24px 24px;
}
.footer__wrap{position:relative;z-index:1;padding:clamp(40px,6vw,72px) 0 0}
.footer__grid{display:grid;gap:32px;grid-template-columns:1fr}
.footer__mark{
  font-family:var(--font-display);font-weight:600;text-transform:uppercase;
  font-size:clamp(30px,5vw,44px);line-height:1;letter-spacing:.03em;color:#fff;
}
.footer__sub{
  margin-top:10px;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.14em;
  color:var(--c-amber);text-transform:uppercase;
}
.footer__facts{display:flex;flex-wrap:wrap;gap:16px 36px;margin-top:24px}
.footer__fact{display:flex;flex-direction:column;gap:4px}
.footer__fact dt{
  font-family:var(--font-mono);font-size:11px;letter-spacing:.12em;
  color:var(--c-muted);text-transform:uppercase;
}
.footer__fact dd{font-family:var(--font-mono);font-size:20px;line-height:1;color:#fff}
.footer__col{min-width:0}
.footer__col-title{
  font-family:var(--font-mono);font-size:11px;font-weight:600;
  letter-spacing:.16em;text-transform:uppercase;color:#fff;
  padding-bottom:10px;margin-bottom:14px;
  border-bottom:1px solid var(--c-grid);
}
.footer__list{display:flex;flex-direction:column;gap:10px}
.footer__link{
  display:inline-block;font-size:13.5px;line-height:1.5;color:#A9B2BA;
  transition:color .18s ease;
}
.footer__link--mono{font-family:var(--font-mono);font-size:12px;letter-spacing:0}
.footer__link:hover{color:var(--c-amber)}
.footer__base{
  display:flex;flex-wrap:wrap;align-items:flex-end;justify-content:space-between;
  gap:14px 40px;
  margin-top:clamp(32px,5vw,56px);
  padding:20px 0 40px;
  border-top:1px solid var(--c-grid);
  font-size:12px;color:var(--c-muted);
}
.footer__note{max-width:62ch;line-height:1.7}
.footer__legal{
  display:flex;flex-wrap:wrap;gap:8px 16px;
  font-family:var(--font-mono);font-size:11.5px;letter-spacing:.02em;
}
.footer__legal a:hover{color:var(--c-amber)}

/* ---------------------------------------------------------- 语义状态 */
.status{
  display:inline-flex;align-items:center;gap:6px;
  padding:4px 8px;border:1px solid currentColor;border-radius:2px;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.08em;text-transform:uppercase;
}
.status--ok{color:var(--c-green)}
.status--warn{color:var(--c-amber)}
.status--bad{color:var(--c-red)}
.tag{
  display:inline-block;padding:4px 8px;border:1px solid var(--c-grid);border-radius:2px;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.1em;
  text-transform:uppercase;color:var(--c-silver);
}
.tag--amber{color:var(--c-amber);border-color:var(--c-amber)}

/* ---------------------------------------------------------- 分区与网格 */
.section{position:relative;padding:clamp(48px,7vw,96px) 0}
.section--dark{background:var(--c-graphite);color:var(--c-silver)}
.section--panel{background:var(--c-panel);color:var(--c-silver)}
.section--cream{background:var(--c-cream);color:var(--c-ink)}
.section__head{
  display:flex;flex-wrap:wrap;align-items:flex-end;justify-content:space-between;
  gap:16px;margin-bottom:clamp(24px,4vw,48px);
}
.section__title{
  font-family:var(--font-display);font-weight:600;
  font-size:clamp(28px,4.6vw,44px);line-height:1.05;letter-spacing:.01em;
  text-transform:uppercase;color:#fff;
}
.section--cream .section__title{color:var(--c-ink)}

.grid{display:grid;gap:20px}
.grid--2{grid-template-columns:repeat(auto-fit,minmax(260px,1fr))}
.grid--3{grid-template-columns:repeat(auto-fit,minmax(220px,1fr))}
.grid--4{grid-template-columns:repeat(auto-fit,minmax(180px,1fr))}

.card{
  position:relative;padding:22px;
  background:var(--c-panel);border:1px solid var(--c-grid);border-radius:0;
}
.card__title{
  font-family:var(--font-display);font-size:18px;font-weight:600;
  letter-spacing:.04em;text-transform:uppercase;color:#fff;line-height:1.3;
}
.card__meta{
  margin-top:8px;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.1em;
  text-transform:uppercase;color:var(--c-muted);
}

/* ---------------------------------------------------------- 数字优先三层 */
.metric{display:flex;flex-direction:column;gap:6px}
.metric__value{
  font-family:var(--font-mono);font-weight:600;
  font-size:clamp(40px,7vw,72px);line-height:1;letter-spacing:-.02em;
  color:var(--c-amber);
}
.metric__label{
  font-family:var(--font-display);font-size:13px;font-weight:600;
  letter-spacing:.1em;text-transform:uppercase;color:#fff;
}
.metric__note{font-size:13px;line-height:1.6;color:var(--c-muted)}
.section--cream .metric__label{color:var(--c-ink)}
.section--cream .metric__note{color:#5A6470}

/* ---------------------------------------------------------- 栏目编号 / 导语 */
.eyebrow{
  display:flex;align-items:center;gap:10px;
  font-family:var(--font-mono);font-size:12px;letter-spacing:.2em;
  text-transform:uppercase;color:var(--c-amber);
}
.eyebrow::before{content:"";width:24px;height:1px;background:var(--c-amber)}
.lede{
  font-family:var(--font-serif);
  font-size:clamp(18px,2vw,22px);line-height:1.85;
  color:#E8EBEE;max-width:34em;
}
.section--cream .lede{color:#2B2B2B}

/* ---------------------------------------------------------- 面包屑 */
.breadcrumb{padding-top:18px}
.breadcrumb__list{
  display:flex;flex-wrap:wrap;align-items:center;gap:8px;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.08em;
  text-transform:uppercase;color:var(--c-muted);
}
.breadcrumb__item{display:inline-flex;align-items:center;gap:8px}
.breadcrumb__item:not(:last-child)::after{content:"/";color:var(--c-grid)}
.breadcrumb__link{transition:color .18s ease}
.breadcrumb__link:hover{color:var(--c-amber)}

/* ---------------------------------------------------------- 长文容器 */
.prose{max-width:40em}
.prose > * + *{margin-top:1.1em}
.prose p{max-width:34em;line-height:1.85}
.prose h2,.prose h3{
  font-family:var(--font-display);font-weight:600;text-transform:uppercase;
  letter-spacing:.02em;line-height:1.25;color:#fff;
}
.prose h2{font-size:clamp(24px,3vw,32px);margin-top:1.9em}
.prose h3{font-size:clamp(18px,2.2vw,22px);margin-top:1.6em}
.prose ul{display:flex;flex-direction:column;gap:.5em}
.prose li{position:relative;padding-left:1.4em}
.prose li::before{
  content:"";position:absolute;left:0;top:.78em;
  width:10px;height:1px;background:var(--c-amber);
}
.prose a{color:var(--c-amber);border-bottom:1px solid rgba(255,122,0,.45)}
.section--cream .prose{color:#2B2B2B}
.section--cream .prose h2,.section--cream .prose h3{color:var(--c-ink)}
.section--cream .prose a{color:#B05200;border-color:rgba(176,82,0,.4)}

/* ---------------------------------------------------------- 规格表 */
.data-table{width:100%;font-size:14px}
.data-table caption{
  text-align:left;padding-bottom:10px;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.1em;
  text-transform:uppercase;color:var(--c-muted);
}
.data-table th{
  text-align:left;padding:10px 12px;
  font-family:var(--font-mono);font-size:11px;font-weight:600;
  letter-spacing:.1em;text-transform:uppercase;color:var(--c-muted);
  border-bottom:1px solid var(--c-grid);white-space:nowrap;
}
.data-table td{
  padding:12px;color:var(--c-silver);
  border-bottom:1px solid var(--c-line);vertical-align:top;
}
.data-table td.num,
.data-table .cell-code{font-family:var(--font-mono);letter-spacing:-.01em}
.data-table tbody tr:nth-child(even){background:rgba(42,42,42,.6)}
.section--cream .data-table th{color:#5A6470;border-color:rgba(15,15,15,.18)}
.section--cream .data-table td{color:var(--c-ink);border-color:rgba(15,15,15,.12)}
.section--cream .data-table tbody tr:nth-child(even){background:rgba(15,15,15,.035)}

/* ---------------------------------------------------------- 媒体容器 */
.media-frame{
  position:relative;display:block;overflow:hidden;
  aspect-ratio:16/10;
  border:1px solid var(--c-grid);border-radius:0;
  background-color:#232323;
  background-image:
    linear-gradient(rgba(59,74,87,.14) 1px,transparent 1px),
    linear-gradient(90deg,rgba(59,74,87,.14) 1px,transparent 1px);
  background-size:24px 24px;
}
.media-frame::after{
  content:"";position:absolute;top:8px;right:8px;z-index:2;
  width:14px;height:14px;opacity:.75;
  border-top:1px solid var(--c-amber);border-right:1px solid var(--c-amber);
}
.media-frame__img{width:100%;height:100%;object-fit:cover}
.media-frame__tag{
  position:absolute;left:0;bottom:0;z-index:2;
  padding:6px 12px;
  background:var(--c-graphite);color:var(--c-amber);
  border-top:1px solid var(--c-grid);border-right:1px solid var(--c-grid);
  font-family:var(--font-mono);font-size:11px;letter-spacing:.12em;text-transform:uppercase;
}
.media-frame--wide{aspect-ratio:21/9}
.media-frame--square{aspect-ratio:1/1}
.media-frame--tall{aspect-ratio:3/4}

/* ---------------------------------------------------------- 滚动索引与显现 */
[data-spy-link]{transition:color .18s ease,border-color .18s ease}
[data-spy-link][aria-current="true"]{color:var(--c-amber)}

.js [data-reveal]{
  opacity:0;transform:translateY(12px);
  transition:opacity .24s ease,transform .24s ease;
}
.js [data-reveal].is-visible{opacity:1;transform:none}

/* ---------------------------------------------------------- 断点 */
@media (min-width:600px){
  .footer__grid{grid-template-columns:repeat(2,minmax(0,1fr))}
  .footer__brand{grid-column:1/-1}
}
@media (min-width:768px){
  .topbar__cta{display:inline-flex}
  body{font-size:16.5px}
}
@media (min-width:960px){
  .footer__grid{grid-template-columns:repeat(4,minmax(0,1fr));gap:36px}
  .footer__brand{
    grid-column:1/-1;
    padding-bottom:32px;
    border-bottom:1px solid var(--c-grid);
  }
}
@media (min-width:1024px){
  body{padding-left:var(--rail-w)}
  .rail{
    top:0;bottom:0;left:0;width:var(--rail-w);
    transform:none;box-shadow:none;
  }
  .topbar{left:var(--rail-w)}
  .nav-scrim{display:none}
  .nav-toggle{display:none}
}

/* ---------------------------------------------------------- 动效降级 */
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{
    animation-duration:.01ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.01ms !important;
    transition-delay:0ms !important;
  }
  .js [data-reveal]{opacity:1;transform:none}
  .rail{transition:none}
}