/* ==========================================================
   88体育主站 · /assets/site.css
   共享外壳：reset / 变量 / 头部 / 页脚 / 基础组件
   ========================================================== */

/* ---------- 1. 变量 ---------- */
:root{
  --ink:#07160F;
  --turf:#1F5C3A;
  --turf-deep:#123B27;
  --orange:#FF5A1F;
  --orange-soft:#FF6E3A;
  --cyan:#3CF2C6;
  --chalk:#EEF3F0;
  --board:#F4F1E8;
  --paper:#E8DFC8;
  --line:#2E4A3C;
  --shade:#030B08;
  --rail-w:88px;
  --topbar-h:72px;
  --dock-h:62px;
  --shell:1440px;
  --font-display:"Oswald","Barlow Condensed","PingFang SC","Microsoft YaHei",sans-serif;
  --font-editorial:"Noto Serif SC","Songti SC","SimSun",serif;
  --font-body:"Noto Sans SC","PingFang SC","Microsoft YaHei","Helvetica Neue",Arial,sans-serif;
  --font-data:"JetBrains Mono","Roboto Mono",SFMono-Regular,Menlo,Consolas,monospace;
  --dur:240ms;
  --ease:cubic-bezier(.2,.7,.3,1);
}

/* ---------- 2. reset ---------- */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
html.is-nav-open,html.is-nav-open body{overflow:hidden}
body{
  margin:0;
  padding-left:var(--rail-w);
  font-family:var(--font-body);
  font-size:17px;
  line-height:1.75;
  color:var(--chalk);
  background-color:var(--ink);
  background-image:
    radial-gradient(1200px 620px at 80% -8%, rgba(31,92,58,.38), transparent 68%),
    repeating-linear-gradient(0deg, rgba(46,74,60,.14) 0 1px, transparent 1px 76px);
  background-repeat:no-repeat,repeat;
  background-attachment:fixed,scroll;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}
img,svg,video{max-width:100%;display:block;height:auto}
a{color:inherit;text-decoration:none}
button{font:inherit;color:inherit;background:none;border:0;cursor:pointer}
ul,ol{margin:0;padding:0;list-style:none}
p{margin:0 0 1.1em}
table{border-collapse:collapse;width:100%}
::selection{background:var(--orange);color:var(--shade)}
:focus-visible{outline:2px solid var(--cyan);outline-offset:3px;border-radius:2px}
#main-content{scroll-margin-top:calc(var(--topbar-h) + 24px)}

/* ---------- 3. 中文排版 ---------- */
h1,h2,h3,h4{
  margin:0 0 .55em;
  font-family:var(--font-display);
  font-weight:600;
  line-height:1.1;
  letter-spacing:.005em;
  color:var(--board);
}
h1{font-size:clamp(2.4rem,5.4vw,4.6rem);letter-spacing:-.01em}
h2{font-size:clamp(1.6rem,3vw,2.4rem)}
h3{font-size:clamp(1.15rem,1.6vw,1.4rem)}
.editorial{font-family:var(--font-editorial);font-weight:400}
.mono,.display-num{font-variant-numeric:tabular-nums}
.mono{font-family:var(--font-data)}
.display-num{font-family:var(--font-display);font-weight:700;letter-spacing:-.04em;line-height:.94;color:var(--board)}
.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}

/* ---------- 4. 跳至主要内容 ---------- */
.skip-link{
  position:fixed;top:12px;left:calc(var(--rail-w) + 16px);z-index:120;
  padding:10px 18px;border-radius:2px;
  background:var(--orange);color:var(--shade);
  font-family:var(--font-data);font-size:13px;letter-spacing:.08em;
  transform:translateY(-180%);
  transition:transform var(--dur) var(--ease);
}
.skip-link:focus{transform:none}

/* ---------- 5. 头部外壳 ---------- */
.site-header{position:relative;z-index:60}

/* 5.1 左侧品牌轨道 */
.brand-rail{
  position:fixed;top:0;left:0;bottom:0;width:var(--rail-w);z-index:70;
  display:flex;flex-direction:column;align-items:center;gap:16px;
  padding:20px 0 22px;
  background:linear-gradient(180deg,var(--turf-deep) 0%,var(--ink) 62%,var(--shade) 100%);
  border-right:1px solid var(--line);
}
.rail-mark{
  display:flex;align-items:center;justify-content:center;
  width:52px;height:52px;border-radius:2px;
  background:var(--orange);color:var(--shade);
  font-family:var(--font-display);font-weight:700;
  box-shadow:0 8px 22px rgba(255,90,31,.28);
  transition:transform var(--dur) var(--ease),box-shadow var(--dur) var(--ease);
}
.rail-mark__num{font-size:26px;line-height:1;letter-spacing:-.06em}
.rail-mark:hover{transform:translateY(-2px);box-shadow:0 12px 26px rgba(255,90,31,.4)}
.rail-slogan{
  margin:0;writing-mode:vertical-rl;
  font-family:var(--font-editorial);font-size:12px;letter-spacing:.34em;
  color:rgba(238,243,240,.5);
}
.rail-paths{
  width:100%;margin-top:auto;
  display:flex;flex-direction:column;
  border-top:1px solid var(--line);
}
.rail-path{
  display:flex;flex-direction:column;align-items:center;gap:2px;
  padding:12px 4px;
  font-size:12px;letter-spacing:.1em;
  color:rgba(238,243,240,.62);
  border-bottom:1px solid var(--line);
  transition:background-color var(--dur) var(--ease),color var(--dur) var(--ease),box-shadow var(--dur) var(--ease);
}
.rail-path__idx{font-family:var(--font-data);font-size:10px;color:var(--cyan);opacity:.75}
.rail-path__label{line-height:1.2}
.rail-path:hover,.rail-path:focus-visible{
  color:var(--board);background-color:rgba(31,92,58,.45);
  box-shadow:inset 3px 0 0 var(--orange);
}
.rail-path[aria-current="page"]{
  color:var(--board);background-color:rgba(31,92,58,.38);
  box-shadow:inset 3px 0 0 var(--orange);
}
.rail-status{
  margin:0;display:flex;flex-direction:column;align-items:center;gap:7px;
  font-family:var(--font-data);font-size:10px;letter-spacing:.16em;
  color:rgba(238,243,240,.42);
}
.rail-status__dot{width:6px;height:6px;border-radius:50%;background:var(--cyan);box-shadow:0 0 10px var(--cyan)}

/* 5.2 阅读进度 */
.readout{
  position:fixed;top:0;left:var(--rail-w);right:0;height:2px;z-index:80;
  background:transparent;pointer-events:none;
}
.readout__bar{
  display:block;height:100%;width:0;
  background:linear-gradient(90deg,var(--cyan),var(--orange));
  transition:width 120ms linear;
}

/* 5.3 顶部导航条 */
.topbar{
  position:fixed;top:0;left:var(--rail-w);right:0;z-index:65;
  background-image:linear-gradient(180deg,rgba(3,11,8,.8),rgba(3,11,8,0));
  border-bottom:1px solid transparent;
  transition:background-color var(--dur) var(--ease),border-color var(--dur) var(--ease),box-shadow var(--dur) var(--ease);
}
.topbar__inner{
  max-width:var(--shell);margin:0 auto;min-height:var(--topbar-h);
  padding:0 36px;display:flex;align-items:center;gap:30px;
}
[data-site-header][data-scrolled="true"] .topbar{
  background-image:none;
  background-color:rgba(7,22,15,.94);
  border-bottom-color:var(--line);
  box-shadow:0 12px 32px rgba(3,11,8,.55);
}
.topbar__brand{display:flex;flex-direction:column;flex:0 0 auto;line-height:1.25}
.topbar__brand-name{font-family:var(--font-display);font-size:19px;font-weight:600;letter-spacing:.02em;color:var(--board)}
.topbar__brand-sub{font-family:var(--font-editorial);font-size:11px;letter-spacing:.22em;color:rgba(238,243,240,.48)}
.topbar__actions{display:flex;align-items:center;gap:14px;flex:0 0 auto}

/* 5.4 主导航 */
.site-nav{margin-left:auto}
.site-nav__list{display:flex;align-items:center;gap:26px}
.site-nav__link{
  position:relative;display:inline-block;padding:8px 0;
  font-size:15px;letter-spacing:.04em;
  color:rgba(238,243,240,.72);
  transition:color var(--dur) var(--ease);
}
.site-nav__link::after{
  content:"";position:absolute;left:0;right:0;bottom:0;height:1px;
  background:var(--orange);transform:scaleX(0);transform-origin:left;
  transition:transform var(--dur) var(--ease);
}
.site-nav__link:hover,.site-nav__link:focus-visible{color:var(--board)}
.site-nav__link:hover::after,.site-nav__link:focus-visible::after{transform:scaleX(1)}
.site-nav__link[aria-current="page"]{color:var(--board)}
.site-nav__link[aria-current="page"]::after{transform:scaleX(1)}
.site-nav__link[aria-current="page"]::before{
  content:"";position:absolute;left:-12px;top:50%;width:5px;height:5px;margin-top:-2.5px;
  border-radius:50%;background:var(--cyan);
}
.site-nav__foot{display:none}

/* 5.5 汉堡开关 */
.nav-toggle{
  display:none;position:relative;width:46px;height:46px;border-radius:2px;
  border:1px solid var(--line);background:rgba(7,22,15,.5);
}
.nav-toggle__bar{
  position:absolute;left:12px;right:12px;height:1.5px;background:var(--board);
  transition:transform var(--dur) var(--ease),opacity var(--dur) var(--ease);
}
.nav-toggle__bar:nth-child(1){top:16px}
.nav-toggle__bar:nth-child(2){top:22px}
.nav-toggle__bar:nth-child(3){top:28px}
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(1){transform:translateY(6px) 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(-6px) rotate(-45deg)}

/* 5.6 移动端路径坞站 */
.dock{
  display:none;position:fixed;left:0;right:0;bottom:0;z-index:75;
  grid-template-columns:repeat(3,minmax(0,1fr));
  background-color:rgba(7,22,15,.96);
  border-top:1px solid var(--line);
  padding-bottom:env(safe-area-inset-bottom);
}
.dock__link{
  display:flex;flex-direction:column;align-items:center;justify-content:center;gap:2px;
  min-height:var(--dock-h);
  font-size:12px;letter-spacing:.12em;
  color:rgba(238,243,240,.66);
  border-right:1px solid rgba(46,74,60,.6);
  transition:color var(--dur) var(--ease),background-color var(--dur) var(--ease);
}
.dock__link:last-child{border-right:0}
.dock__idx{font-family:var(--font-data);font-size:10px;color:var(--cyan);opacity:.7}
.dock__link[aria-current="page"]{color:var(--orange);box-shadow:inset 0 2px 0 var(--orange)}

/* ---------- 6. 页脚 ---------- */
.site-footer{
  position:relative;
  border-top:1px solid var(--line);
  background-color:var(--shade);
  background-image:
    linear-gradient(180deg,rgba(7,22,15,.72),rgba(3,11,8,1) 42%),
    repeating-linear-gradient(90deg,rgba(46,74,60,.16) 0 1px,transparent 1px 64px);
}
.footer__inner{max-width:var(--shell);margin:0 auto;padding:72px 40px 36px}
.footer__top{
  display:grid;grid-template-columns:minmax(0,1.05fr) minmax(0,1.7fr);
  gap:56px;padding-bottom:48px;border-bottom:1px solid var(--line);
}
.footer__brand-col{min-width:0}
.footer__brand{
  margin:0 0 14px;font-family:var(--font-display);font-weight:600;
  font-size:clamp(1.4rem,2.6vw,2.1rem);line-height:1.2;letter-spacing:.01em;color:var(--board);
}
.footer__tagline{
  margin:0 0 22px;max-width:34ch;
  font-family:var(--font-editorial);font-size:17px;line-height:1.7;
  color:rgba(238,243,240,.7);
}
.footer__status{
  display:inline-flex;align-items:center;gap:10px;margin:0;
  font-family:var(--font-data);font-size:11px;letter-spacing:.18em;
  color:rgba(60,242,198,.85);
}
.footer__status-dot{width:7px;height:7px;border-radius:50%;background:var(--cyan);box-shadow:0 0 10px var(--cyan)}
.footer__cols{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:32px}
.footer__col{min-width:0}
.footer__col-title{
  margin:0 0 16px;font-family:var(--font-data);font-size:11px;letter-spacing:.2em;
  text-transform:uppercase;color:rgba(238,243,240,.45);
}
.footer__links{display:flex;flex-direction:column;gap:11px}
.footer__link{
  display:inline-block;font-size:15px;color:rgba(238,243,240,.72);
  transition:color var(--dur) var(--ease),transform var(--dur) var(--ease);
}
.footer__link:hover,.footer__link:focus-visible{color:var(--orange);transform:translateX(4px)}
.footer__contact{
  display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:28px;
  padding:38px 0;border-bottom:1px solid var(--line);
}
.footer__contact-item{display:flex;flex-direction:column;align-items:flex-start;gap:10px;min-width:0}
.footer__contact-label{font-family:var(--font-data);font-size:11px;letter-spacing:.2em;color:rgba(238,243,240,.45)}
.footer__contact-value{font-size:15px;color:var(--board);word-break:break-all}
.footer__note{
  margin:26px 0 0;max-width:76ch;
  font-size:13px;line-height:1.85;color:rgba(238,243,240,.5);
}
.footer__bottom{
  display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:14px;
  margin-top:28px;padding-top:22px;border-top:1px solid rgba(46,74,60,.55);
  font-family:var(--font-data);font-size:12px;letter-spacing:.08em;color:rgba(238,243,240,.45);
}
.footer__legal{white-space:nowrap}

/* ---------- 7. 通用组件 ---------- */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  padding:11px 20px;border-radius:2px;
  border:1px solid var(--line);background:transparent;color:var(--board);
  font-size:14px;letter-spacing:.06em;
  transition:background-color var(--dur) var(--ease),color var(--dur) var(--ease),border-color var(--dur) var(--ease),transform var(--dur) var(--ease);
}
.btn--primary{
  background:var(--orange);border-color:var(--orange);color:var(--shade);font-weight:600;
  box-shadow:0 10px 24px rgba(255,90,31,.24);
}
.btn--primary:hover,.btn--primary:focus-visible{background:var(--orange-soft);border-color:var(--orange-soft);transform:translateY(-1px)}
.btn--ghost{background:rgba(7,22,15,.45)}
.btn--ghost:hover,.btn--ghost:focus-visible{border-color:var(--orange);color:#fff}
.btn--quiet{padding:8px 14px;font-size:13px;background:rgba(18,59,39,.5);color:rgba(238,243,240,.7)}
.btn--quiet:hover,.btn--quiet:focus-visible{border-color:var(--line);color:var(--board)}

.page-shell{max-width:var(--shell);margin:0 auto;padding:calc(var(--topbar-h) + 56px) 40px 110px}

.breadcrumbs{
  display:flex;flex-wrap:wrap;align-items:center;gap:8px;
  margin:0 0 34px;
  font-family:var(--font-data);font-size:11px;letter-spacing:.16em;
  color:rgba(238,243,240,.5);
}
.breadcrumbs a:hover,.breadcrumbs a:focus-visible{color:var(--orange)}
.breadcrumbs__sep{color:var(--line)}

.section-head{max-width:780px;margin:0 0 40px}
.eyebrow{
  display:inline-flex;align-items:center;gap:10px;
  margin:0 0 14px;
  font-family:var(--font-data);font-size:11px;letter-spacing:.22em;text-transform:uppercase;
  color:var(--cyan);
}
.eyebrow::before{content:"";width:22px;height:1px;background:var(--cyan)}
.section-title{margin:0 0 .4em}
.section-lead{max-width:62ch;font-size:18px;color:rgba(238,243,240,.72)}

.chapter{
  display:grid;grid-template-columns:96px minmax(0,1fr);gap:28px;
  padding:44px 0;border-top:1px solid var(--line);
}
.chapter__num{font-family:var(--font-data);font-size:13px;letter-spacing:.18em;color:var(--orange);padding-top:6px}
.chapter__main{min-width:0}
.chapter__title{margin:0 0 .5em}
.chapter__body{max-width:70ch;color:rgba(238,243,240,.76)}

.grid{display:grid;gap:26px}
.grid--2{grid-template-columns:repeat(2,minmax(0,1fr))}
.grid--3{grid-template-columns:repeat(3,minmax(0,1fr))}
.grid--5-7{grid-template-columns:5fr 7fr}
.grid--7-5{grid-template-columns:7fr 5fr}
.grid--4-8{grid-template-columns:4fr 8fr}

.panel{
  position:relative;padding:26px 24px;border-radius:3px;
  border:1px solid var(--line);
  background-image:linear-gradient(180deg,rgba(18,59,39,.72),rgba(7,22,15,.92));
}
.panel--board{
  background-color:var(--turf-deep);
  background-image:
    repeating-linear-gradient(90deg,rgba(238,243,240,.045) 0 1px,transparent 1px 46px),
    repeating-linear-gradient(0deg,rgba(238,243,240,.045) 0 1px,transparent 1px 46px);
}
.panel__label{
  margin:0 0 10px;font-family:var(--font-data);font-size:11px;letter-spacing:.2em;color:var(--cyan);
}

.card{
  display:flex;flex-direction:column;overflow:hidden;
  border:1px solid var(--line);border-radius:3px;
  background-color:rgba(18,59,39,.5);
  transition:transform var(--dur) var(--ease),border-color var(--dur) var(--ease),box-shadow var(--dur) var(--ease);
}
.card:hover,.card:focus-within{
  transform:translateY(-3px);border-color:rgba(255,90,31,.6);
  box-shadow:0 16px 36px rgba(3,11,8,.55);
}
.card__media{position:relative;overflow:hidden;border-bottom:1px solid var(--line)}
.card__body{padding:20px 20px 24px}
.card__meta{
  display:flex;flex-wrap:wrap;align-items:center;gap:10px;margin-bottom:12px;
  font-family:var(--font-data);font-size:11px;letter-spacing:.14em;color:rgba(238,243,240,.55);
}
.card__title{margin:0 0 8px;font-family:var(--font-display);font-size:20px;color:var(--board)}
.card__text{margin:0;font-size:15px;line-height:1.7;color:rgba(238,243,240,.7)}

.figure{margin:0;display:block}
.figure__media{
  position:relative;overflow:hidden;border-radius:3px;
  border:1px solid var(--line);background-color:var(--turf-deep);
  aspect-ratio:16 / 9;
}
.figure__media > img{width:100%;height:100%;object-fit:cover;transition:transform 400ms var(--ease)}
.figure__media--wide{aspect-ratio:21 / 9}
.figure__media--square{aspect-ratio:1 / 1}
.figure__media--tall{aspect-ratio:3 / 4}
.figure__media--scrim::after{
  content:"";position:absolute;inset:0;pointer-events:none;
  background:linear-gradient(180deg,rgba(3,11,8,0) 38%,rgba(3,11,8,.78));
}
.figure__badge{
  position:absolute;left:12px;top:12px;z-index:2;
  padding:5px 9px;border-radius:2px;border:1px solid var(--line);
  background-color:rgba(3,11,8,.72);
  font-family:var(--font-data);font-size:10px;letter-spacing:.16em;color:var(--chalk);
}
.figure__caption{margin-top:12px;font-size:13px;line-height:1.75;color:rgba(238,243,240,.55)}
a:hover .figure__media > img,a:focus-visible .figure__media > img{transform:scale(1.03)}

.tag{
  display:inline-flex;align-items:center;gap:6px;
  padding:4px 10px;border-radius:2px;border:1px solid var(--line);
  background-color:rgba(7,22,15,.5);
  font-family:var(--font-data);font-size:11px;letter-spacing:.14em;color:rgba(238,243,240,.72);
}
.tag--live{color:var(--cyan);border-color:rgba(60,242,198,.45)}
.tag--live::before{content:"";width:6px;height:6px;border-radius:50%;background:var(--cyan);box-shadow:0 0 8px var(--cyan)}
.tag--hot{background:var(--orange);border-color:var(--orange);color:var(--shade);font-weight:700}
.tag--archive{background:var(--paper);border-color:var(--paper);color:#33301F}

.data-strip{
  display:grid;grid-template-columns:repeat(auto-fit,minmax(150px,1fr));
  overflow:hidden;border:1px solid var(--line);border-radius:3px;
  background-color:rgba(3,11,8,.5);
}
.data-strip__item{padding:22px 20px;border-right:1px solid var(--line)}
.data-strip__item:last-child{border-right:0}
.data-strip__num{
  display:block;font-family:var(--font-data);font-variant-numeric:tabular-nums;
  font-size:clamp(26px,3.4vw,40px);line-height:1.05;letter-spacing:-.02em;color:var(--board);
}
.data-strip__num--accent{color:var(--orange)}
.data-strip__label{display:block;margin-top:8px;font-size:12px;letter-spacing:.14em;color:rgba(238,243,240,.55)}

.filter-bar{
  display:flex;flex-wrap:wrap;gap:8px;margin-bottom:32px;padding:10px;
  border:1px solid var(--line);border-radius:3px;background-color:rgba(7,22,15,.6);
}
.filter-btn{
  padding:8px 16px;border-radius:2px;border:1px solid transparent;
  font-size:13px;letter-spacing:.08em;color:rgba(238,243,240,.66);
  transition:color var(--dur) var(--ease),background-color var(--dur) var(--ease),border-color var(--dur) var(--ease);
}
.filter-btn:hover,.filter-btn:focus-visible{color:var(--board);border-color:var(--line)}
.filter-btn[aria-pressed="true"]{background:var(--orange);border-color:var(--orange);color:var(--shade);font-weight:600}
[data-tag][hidden]{display:none}
.is-filtered-in{animation:fadeUp 280ms var(--ease) both}

.copy-btn{
  display:inline-flex;align-items:center;gap:8px;
  padding:6px 12px;border-radius:2px;border:1px solid var(--line);
  background-color:rgba(7,22,15,.5);
  font-family:var(--font-data);font-size:11px;letter-spacing:.14em;color:rgba(238,243,240,.66);
  transition:color var(--dur) var(--ease),border-color var(--dur) var(--ease);
}
.copy-btn:hover,.copy-btn:focus-visible{color:var(--board);border-color:var(--orange)}
.copy-btn[data-copied="true"]{color:var(--cyan);border-color:rgba(60,242,198,.5)}

.rule{height:1px;margin:56px 0;border:0;background:var(--line)}
.turf-strip{
  border-top:1px solid var(--line);border-bottom:1px solid var(--line);
  background-color:var(--turf-deep);
  background-image:repeating-linear-gradient(90deg,rgba(238,243,240,.05) 0 1px,transparent 1px 54px);
}

html.js-ready [data-reveal]{
  opacity:0;transform:translateY(14px);
  transition:opacity 520ms var(--ease),transform 520ms var(--ease);
}
html.js-ready [data-reveal].is-visible{opacity:1;transform:none}

@keyframes fadeUp{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:none}}

/* ---------- 8. 平板 ---------- */
@media (max-width:1100px){
  .topbar__inner{padding:0 22px;gap:18px}
  .site-nav__list{gap:18px}
  .site-nav__link{font-size:14px}
  .topbar__brand-sub{display:none}
  .footer__top{grid-template-columns:1fr;gap:38px}
}

/* ---------- 9. 移动端 ---------- */
@media (max-width:900px){
  :root{--topbar-h:64px}
  body{padding-left:0;padding-bottom:calc(var(--dock-h) + env(safe-area-inset-bottom))}
  .brand-rail{display:none}
  .readout{left:0}
  .topbar{left:0}
  .topbar__inner{padding:0 18px;gap:12px}
  .topbar__actions{margin-left:auto}
  .nav-toggle{display:block}
  .dock{display:grid}

  .site-nav{
    position:fixed;inset:0;z-index:1;margin-left:0;
    display:flex;flex-direction:column;gap:18px;
    padding:calc(var(--topbar-h) + 28px) 22px 34px;
    overflow-y:auto;
    background-color:rgba(7,22,15,.985);
    opacity:0;visibility:hidden;transform:translateY(-10px);
    transition:opacity var(--dur) var(--ease),transform var(--dur) var(--ease),visibility var(--dur) var(--ease);
  }
  .site-nav[data-open="true"]{opacity:1;visibility:visible;transform:none}
  .site-nav__list{flex-direction:column;align-items:stretch;gap:0;border-top:1px solid var(--line)}
  .site-nav__item{border-bottom:1px solid var(--line)}
  .site-nav__link{display:block;padding:18px 4px;font-size:20px;letter-spacing:.02em}
  .site-nav__link::after{display:none}
  .site-nav__link[aria-current="page"]{color:var(--orange)}
  .site-nav__link[aria-current="page"]::before{display:none}
  .site-nav__foot{display:flex;flex-direction:column;align-items:flex-start;gap:14px;margin-top:auto}
  .site-nav__note{
    margin:0;font-family:var(--font-data);font-size:11px;letter-spacing:.18em;
    color:rgba(60,242,198,.8);
  }

  .page-shell{padding:calc(var(--topbar-h) + 32px) 20px 72px}
  .chapter{grid-template-columns:1fr;gap:10px;padding:34px 0}
  .chapter__num{padding-top:0}
  .grid--2,.grid--3,.grid--5-7,.grid--7-5,.grid--4-8{grid-template-columns:1fr}
  .footer__inner{padding:56px 20px 30px}
  .footer__cols{grid-template-columns:repeat(2,minmax(0,1fr));gap:26px}
  .footer__contact{grid-template-columns:1fr;gap:22px;padding:32px 0}
  .footer__bottom{justify-content:flex-start}
  .data-strip__item{border-right:0;border-bottom:1px solid var(--line)}
  .data-strip__item:last-child{border-bottom:0}
}

@media (max-width:640px){
  .topbar__cta{display:none}
  .topbar__brand-name{font-size:17px}
  .section-lead{font-size:16px}
  .footer__cols{grid-template-columns:1fr}
}

/* ---------- 10. 关闭动效 ---------- */
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
  }
  html.js-ready [data-reveal]{opacity:1;transform:none}
  .readout__bar{transition:none}
}