/* ==========================================================================
   FB赛事中心 · 共享样式 /assets/site.css
   展览画册式布局 + 侧轨导航 + 战术板组件原型
   ========================================================================== */

/* ---------- 1. Reset ---------- */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth;scroll-padding-top:84px}
body,h1,h2,h3,h4,h5,p,figure,blockquote,dl,dd,ol,ul{margin:0}
ol,ul{padding:0;list-style:none}
img,svg,video{display:block;max-width:100%}
button,input,select,textarea{font:inherit;color:inherit}
button{background:none;border:0;padding:0;cursor:pointer}
a{color:inherit;text-decoration:none}
table{border-collapse:collapse}
main{display:block}

/* ---------- 2. 设计令牌 ---------- */
:root{
  --ink:#0B1030;
  --ink-2:#16204F;
  --ink-3:#05081C;
  --whistle:#E8FF3A;
  --whistle-soft:#F4FF9C;
  --amber:#FF5A2B;
  --steel:#2A3350;
  --mist:#A9B2CC;
  --white:#F4F7FF;
  --cyan:#37E0C8;

  --text:var(--white);
  --muted:var(--mist);
  --line:rgba(169,178,204,.16);
  --line-strong:rgba(169,178,204,.30);

  --font-display:"Barlow Condensed","Oswald","Arial Narrow","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  --font-body:"Noto Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,-apple-system,"Segoe UI",sans-serif;
  --font-mono:"JetBrains Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,"Liberation Mono",monospace;

  --step-1:12px; --step-2:14px; --step-3:17px; --step-4:22px;
  --step-5:28px; --step-6:40px; --step-7:64px; --step-8:96px;

  --top-h:60px;
  --rail-w:88px;
  --gap:24px;
  --radius:2px;
  --shadow-1:0 1px 0 rgba(5,8,28,.55),0 0 0 1px rgba(169,178,204,.06);
  --shadow-2:0 6px 22px -16px rgba(0,0,0,.9);
  --ease:cubic-bezier(.22,.61,.36,1);
}

/* ---------- 3. 基础排版 ---------- */
body{
  font-family:var(--font-body);
  font-size:var(--step-3);
  line-height:1.75;
  color:var(--text);
  background:
    radial-gradient(1200px 620px at 78% -10%,rgba(55,224,200,.09),transparent 62%),
    radial-gradient(900px 520px at 4% 2%,rgba(232,255,58,.06),transparent 60%),
    var(--ink);
  background-attachment:fixed;
  padding-top:var(--top-h);
  min-height:100vh;
  overflow-x:hidden;
}
body.nav-open{overflow:hidden}

h1,h2,h3,h4{
  font-family:var(--font-display);
  font-weight:700;
  font-stretch:condensed;
  line-height:1.06;
  letter-spacing:.01em;
}
h1{font-size:clamp(32px,4vw,48px)}
h2{font-size:clamp(26px,3.4vw,40px)}
h3{font-size:clamp(20px,2.2vw,28px)}

::selection{background:var(--whistle);color:var(--ink-3)}

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

.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;
}

.skip-link{
  position:fixed;top:10px;left:10px;z-index:200;
  display:inline-flex;align-items:center;
  padding:10px 16px;border-radius:2px;
  background:var(--whistle);color:var(--ink-3);
  font-size:14px;font-weight:700;letter-spacing:.04em;
  transform:translateY(-180%);
  transition:transform .18s var(--ease);
}
.skip-link:focus{transform:translateY(0)}

/* ---------- 4. 布局工具 ---------- */
.shell{
  width:100%;max-width:1280px;margin-inline:auto;
  padding-inline:clamp(18px,4vw,48px);
}
.shell--narrow{max-width:960px}

.section{padding-block:clamp(56px,7.5vw,112px)}
.section--tight{padding-block:clamp(34px,4.5vw,64px)}
.section--flush{padding-top:clamp(28px,4vw,56px);padding-bottom:0}
.section-head{margin-bottom:clamp(24px,3vw,40px)}

.divider{height:1px;border:0;background:linear-gradient(90deg,var(--line-strong),transparent)}

.grid{display:grid;gap:var(--gap)}
.grid--halves{grid-template-columns:repeat(auto-fit,minmax(280px,1fr))}
.grid--thirds{grid-template-columns:repeat(auto-fit,minmax(230px,1fr))}
.grid--12{display:grid;grid-template-columns:repeat(12,minmax(0,1fr));gap:var(--gap)}
.grid--12 > *{grid-column:1 / -1;min-width:0}
@media (min-width:900px){
  .grid--12 > .span-3{grid-column:span 3}
  .grid--12 > .span-4{grid-column:span 4}
  .grid--12 > .span-5{grid-column:span 5}
  .grid--12 > .span-6{grid-column:span 6}
  .grid--12 > .span-7{grid-column:span 7}
  .grid--12 > .span-8{grid-column:span 8}
  .grid--12 > .span-9{grid-column:span 9}
  .grid--12 > .span-12{grid-column:span 12}
}

/* ---------- 5. 文本组件 ---------- */
.kicker{
  display:inline-flex;align-items:center;gap:10px;
  font-family:var(--font-mono);font-size:12px;letter-spacing:.18em;
  text-transform:uppercase;color:var(--whistle);
}
.kicker::before{content:"";width:22px;height:1px;background:currentColor}

.h-display{
  font-family:var(--font-display);
  font-weight:700;font-stretch:condensed;
  font-size:clamp(44px,7vw,96px);
  line-height:.94;letter-spacing:-.005em;
  color:var(--white);
}

.lede{font-size:clamp(16px,1.5vw,19px);line-height:1.7;color:var(--mist);max-width:62ch}

.prose{max-width:68ch;font-size:var(--step-3);line-height:1.75;color:var(--white)}
.prose--dense{font-size:15px;line-height:1.6}
.prose p + p{margin-top:1em}
.prose a{color:var(--whistle);border-bottom:1px solid rgba(232,255,58,.35)}
.prose a:hover{color:var(--whistle-soft)}

/* ---------- 6. 按钮与标签 ---------- */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  padding:10px 18px;border-radius:2px;
  border:1px solid var(--line-strong);
  background:rgba(22,32,79,.6);color:var(--white);
  font-size:14px;font-weight:600;letter-spacing:.04em;line-height:1.2;
  transition:border-color .18s var(--ease),color .18s var(--ease),
             background-color .18s var(--ease),transform .18s var(--ease);
}
.btn:hover{border-color:var(--whistle-soft);color:var(--whistle-soft);transform:translateY(-1px)}
.btn--primary{background:var(--whistle);border-color:var(--whistle);color:var(--ink-3)}
.btn--primary:hover{background:var(--whistle-soft);border-color:var(--whistle-soft);color:var(--ink-3)}
.btn--ghost{background:transparent;color:var(--mist)}
.btn--sm{padding:7px 12px;font-size:13px}

.badge{
  display:inline-flex;align-items:center;gap:6px;
  padding:3px 9px;border:1px solid var(--line-strong);border-radius:2px;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.08em;
  text-transform:uppercase;color:var(--mist);
}
.badge--whistle{background:var(--whistle);border-color:var(--whistle);color:var(--ink-3)}
.badge--amber{background:rgba(255,90,43,.09);border-color:rgba(255,90,43,.5);color:var(--amber)}
.badge--cyan{background:rgba(55,224,200,.08);border-color:rgba(55,224,200,.45);color:var(--cyan)}

/* ---------- 7. 专题研究板 ---------- */
.board{
  position:relative;overflow:hidden;
  display:grid;grid-template-columns:1fr;gap:clamp(20px,2.4vw,32px);
  padding:clamp(20px,2.6vw,34px);
  border:1px solid var(--line);border-radius:var(--radius);
  background:linear-gradient(160deg,rgba(22,32,79,.86),rgba(11,16,48,.72));
  box-shadow:var(--shadow-1);
}
.board::after{
  content:"";position:absolute;right:-12%;bottom:-58%;
  width:320px;height:320px;pointer-events:none;
  background:radial-gradient(circle,rgba(232,255,58,.12),transparent 64%);
}
.board__head{display:flex;flex-direction:column;gap:10px;min-width:0}
.board__summary{
  font-size:clamp(18px,1.9vw,22px);font-weight:600;line-height:1.5;
  color:var(--white);max-width:52ch;
}
.board__body{min-width:0}
.board__aside{padding-top:18px;border-top:1px solid var(--line)}
.board__terms{font-size:13px;line-height:1.65;color:var(--mist)}
.board__terms dt{font-family:var(--font-mono);font-size:12px;letter-spacing:.04em;color:var(--white)}
.board__terms dd{margin:2px 0 12px}
.board__more{
  display:inline-flex;align-items:center;gap:8px;
  font-size:13px;letter-spacing:.04em;color:var(--whistle);
}
.board__more:hover{color:var(--whistle-soft)}
@media (min-width:900px){
  .board{grid-template-columns:minmax(0,1fr) 240px}
  .board__head{grid-column:1 / -1}
  .board__aside{padding-top:0;padding-left:20px;border-top:0;border-left:1px solid var(--line)}
}

.card{
  position:relative;display:flex;flex-direction:column;gap:12px;
  padding:20px;border:1px solid var(--line);border-radius:var(--radius);
  background:rgba(22,32,79,.55);box-shadow:var(--shadow-1);
  transition:border-color .2s var(--ease),transform .2s var(--ease),background-color .2s var(--ease);
}
.card:hover{border-color:rgba(244,255,156,.42);background:rgba(22,32,79,.78);transform:translateY(-2px)}
.card--tall{padding:26px}
.card__title{font-family:var(--font-display);font-size:22px;font-weight:700;line-height:1.15;color:var(--white)}
.card__meta{font-family:var(--font-mono);font-size:12px;letter-spacing:.04em;color:var(--mist)}

/* ---------- 8. 数据组件 ---------- */
.stat{display:flex;flex-direction:column;gap:5px;min-width:0}
.stat__value{
  font-family:var(--font-mono);font-variant-numeric:tabular-nums;
  font-weight:700;font-size:clamp(32px,5vw,64px);line-height:1;
  letter-spacing:-.02em;color:var(--white);
}
.stat__value--whistle{color:var(--whistle)}
.stat__value--amber{color:var(--amber)}
.stat__value--cyan{color:var(--cyan)}
.stat__unit{font-size:.34em;font-weight:500;color:var(--mist);margin-left:.4em;letter-spacing:0}
.stat__label{font-size:13px;letter-spacing:.04em;color:var(--mist)}
.stat-row{display:grid;gap:20px;grid-template-columns:repeat(auto-fit,minmax(150px,1fr))}

.table-wrap{
  overflow:auto;border:1px solid var(--line);border-radius:var(--radius);
  background:rgba(5,8,28,.5);
}
.data-table{width:100%;min-width:520px;font-size:14px;line-height:1.5}
.data-table th,.data-table td{
  padding:11px 14px;text-align:left;white-space:nowrap;
  border-bottom:1px solid var(--line);
}
.data-table thead th{
  position:sticky;top:0;z-index:2;
  background:var(--ink-3);color:var(--mist);
  font-family:var(--font-mono);font-size:12px;font-weight:500;letter-spacing:.08em;
}
.data-table tbody th{position:sticky;left:0;z-index:1;background:var(--ink-2);font-weight:500}
.data-table tbody tr:nth-child(even){background:rgba(42,51,80,.32)}
.data-table tbody tr:hover{background:rgba(42,51,80,.72)}
.data-table .num{
  text-align:right;font-family:var(--font-mono);
  font-variant-numeric:tabular-nums;color:var(--white);
}

/* ---------- 9. 目录与面包屑 ---------- */
.toc{display:flex;flex-direction:column;gap:2px;border-left:1px solid var(--line)}
.toc__link{
  display:block;margin-left:-1px;padding:7px 0 7px 14px;
  border-left:2px solid transparent;
  font-size:13px;line-height:1.4;color:var(--mist);
  transition:color .18s var(--ease),border-color .18s var(--ease);
}
.toc__link:hover{color:var(--white)}
.toc__link[aria-current="true"]{color:var(--whistle);border-left-color:var(--whistle)}

.breadcrumbs{
  display:flex;flex-wrap:wrap;gap:8px;
  font-family:var(--font-mono);font-size:12px;letter-spacing:.05em;color:var(--mist);
}
.breadcrumbs li{display:inline-flex;align-items:center;gap:8px}
.breadcrumbs li::after{content:"/";color:rgba(169,178,204,.4)}
.breadcrumbs li:last-child::after{content:"";display:none}
.breadcrumbs a:hover{color:var(--whistle-soft)}

/* ---------- 10. 图片容器 ---------- */
.media{margin:0;min-width:0}
.media__frame{
  position:relative;width:100%;aspect-ratio:16 / 9;overflow:hidden;
  border:1px solid var(--line);border-radius:var(--radius);
  background:linear-gradient(135deg,rgba(22,32,79,.92),rgba(5,8,28,.94));
}
.media__frame img{width:100%;height:100%;object-fit:cover;filter:saturate(.92) contrast(1.04)}
.media__frame::after{
  content:"";position:absolute;inset:0;pointer-events:none;
  background:linear-gradient(180deg,transparent 48%,rgba(5,8,28,.72));
}
.media--4x3 .media__frame{aspect-ratio:4 / 3}
.media--1x1 .media__frame{aspect-ratio:1 / 1}
.media--tall .media__frame{aspect-ratio:3 / 4}
.media__caption{margin-top:9px;font-size:12px;line-height:1.55;color:var(--mist)}

/* ---------- 11. 页头 ---------- */
.site-header{position:relative;z-index:80}

.scroll-progress{
  position:fixed;top:0;left:0;right:0;height:2px;z-index:95;
  opacity:0;pointer-events:none;transition:opacity .2s var(--ease);
}
.scroll-progress[data-active]{opacity:1}
.scroll-progress__bar{
  display:block;height:100%;width:0;
  background:linear-gradient(90deg,var(--whistle),var(--cyan));
}

.site-top{
  position:fixed;top:0;left:0;right:0;height:var(--top-h);z-index:90;
  display:flex;align-items:center;gap:clamp(10px,1.6vw,22px);
  padding-inline:clamp(12px,2vw,22px);
  background:rgba(5,8,28,.90);
  -webkit-backdrop-filter:blur(12px);
  backdrop-filter:blur(12px);
  border-bottom:1px solid var(--line);
  transition:background-color .2s var(--ease);
}
.site-header.is-condensed .site-top{background:rgba(5,8,28,.97)}
.site-header.is-condensed .brand__tagline{display:none}
.site-header.is-condensed .brand__mark{width:34px;height:34px;font-size:15px}

.brand{display:flex;align-items:center;gap:10px;min-width:0}
.brand__mark{
  flex:none;width:40px;height:40px;display:grid;place-items:center;
  font-family:var(--font-display);font-size:18px;font-weight:700;letter-spacing:.02em;
  color:var(--ink-3);
  background:linear-gradient(150deg,var(--whistle),var(--whistle-soft) 68%,var(--cyan));
  clip-path:polygon(0 0,100% 0,100% 74%,74% 100%,0 100%);
  transition:width .2s var(--ease),height .2s var(--ease),font-size .2s var(--ease);
}
.brand__text{display:flex;flex-direction:column;min-width:0}
.brand__name{
  font-family:var(--font-display);font-size:19px;font-weight:700;
  letter-spacing:.04em;line-height:1.15;color:var(--white);
}
.brand__tagline{
  font-size:11px;letter-spacing:.08em;line-height:1.4;
  color:var(--mist);white-space:nowrap;overflow:hidden;text-overflow:ellipsis;
}

.round-switcher{
  display:none;align-items:center;gap:2px;
  padding:3px 5px;border:1px solid var(--line-strong);border-radius:2px;
  background:rgba(22,32,79,.65);
}
.round-switcher__label{font-size:11px;color:var(--mist);padding-inline:3px}
.round-switcher__value{
  min-width:2.4ch;text-align:center;
  font-family:var(--font-mono);font-variant-numeric:tabular-nums;
  font-size:16px;font-weight:700;color:var(--whistle);
}
.round-switcher__step{
  width:22px;height:22px;display:grid;place-items:center;
  border-radius:2px;color:var(--mist);
  font-family:var(--font-mono);font-size:14px;line-height:1;
  transition:background-color .16s var(--ease),color .16s var(--ease);
}
.round-switcher__step:hover{background:var(--whistle-soft);color:var(--ink-3)}

.site-top__meta{
  display:none;align-items:center;gap:8px;
  font-family:var(--font-mono);font-size:12px;letter-spacing:.03em;color:var(--mist);
}
.pulse-dot{
  flex:none;width:6px;height:6px;border-radius:50%;
  background:var(--cyan);box-shadow:0 0 0 3px rgba(55,224,200,.18);
}

.site-top__actions{display:none;align-items:center;gap:10px}
.site-top__actions .btn{display:none}

.nav-toggle{
  display:inline-flex;align-items:center;gap:9px;
  margin-left:auto;padding:8px 12px;
  border:1px solid var(--line-strong);border-radius:2px;
  font-size:13px;letter-spacing:.06em;color:var(--white);
  transition:border-color .18s var(--ease),color .18s var(--ease);
}
.nav-toggle:hover{border-color:var(--whistle-soft);color:var(--whistle-soft)}
.nav-toggle[aria-expanded="true"]{border-color:var(--whistle);color:var(--whistle)}
.nav-toggle__bars{position:relative;display:block;width:18px;height:12px;flex:none}
.nav-toggle__bars::before,
.nav-toggle__bars::after{
  content:"";position:absolute;left:0;width:100%;height:1.5px;
  background:currentColor;
  transition:transform .2s var(--ease);
}
.nav-toggle__bars::before{top:0}
.nav-toggle__bars::after{bottom:0}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::before{transform:translateY(5px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::after{transform:translateY(-5px) rotate(-45deg)}
.nav-toggle__text{white-space:nowrap}

.site-rail{
  position:fixed;top:var(--top-h);bottom:0;left:0;z-index:85;
  width:min(82vw,320px);
  display:flex;flex-direction:column;gap:16px;
  padding:18px 16px 22px;
  overflow-y:auto;-webkit-overflow-scrolling:touch;
  background:linear-gradient(180deg,#101838,#080D24);
  border-right:1px solid var(--line);
  transform:translateX(-102%);
  visibility:hidden;
  transition:transform .3s var(--ease),visibility .3s var(--ease);
}
.site-rail[data-open]{transform:translateX(0);visibility:visible}

.rail-list{display:flex;flex-direction:column;gap:4px}
.rail-item{min-width:0}
.rail-link{
  display:flex;align-items:center;gap:12px;
  padding:12px 14px;
  border-left:2px solid transparent;
  font-size:15px;color:var(--mist);
  transition:color .18s var(--ease),background-color .18s var(--ease),border-color .18s var(--ease);
}
.rail-link__idx{
  font-family:var(--font-mono);font-size:11px;letter-spacing:.08em;
  color:rgba(169,178,204,.6);
  transition:color .18s var(--ease);
}
.rail-link__label{font-weight:500;letter-spacing:.03em;line-height:1.3}
.rail-link:hover{color:var(--white);background:rgba(42,51,80,.5)}
.rail-link[aria-current="page"]{
  color:var(--whistle);border-left-color:var(--whistle);
  background:linear-gradient(90deg,rgba(232,255,58,.12),transparent 72%);
}
.rail-link[aria-current="page"] .rail-link__idx{color:var(--whistle)}

.rail-foot{
  margin-top:auto;padding-top:16px;
  border-top:1px solid var(--line);
  font-family:var(--font-mono);font-size:10px;letter-spacing:.12em;
  color:rgba(169,178,204,.5);text-align:left;
}

.nav-scrim{
  position:fixed;top:var(--top-h);left:0;right:0;bottom:0;z-index:84;
  background:rgba(5,8,28,.74);
  opacity:0;pointer-events:none;
  transition:opacity .24s var(--ease);
}
.nav-scrim[data-open]{opacity:1;pointer-events:auto}

/* ---------- 12. 页脚 ---------- */
.site-footer{
  position:relative;overflow:hidden;
  margin-top:clamp(48px,6vw,96px);
  padding-block:clamp(48px,6vw,88px) 26px;
  background:linear-gradient(180deg,var(--ink-3),#02040F);
  border-top:1px solid var(--line);
}
.site-footer::before{
  content:"";position:absolute;top:-40%;right:8%;
  width:560px;height:560px;pointer-events:none;
  background:radial-gradient(circle,rgba(232,255,58,.07),transparent 62%);
}
.site-footer .shell{position:relative;z-index:1}

.footer-grid{display:grid;grid-template-columns:1fr;gap:clamp(28px,4vw,48px)}

.footer-brand{display:flex;flex-direction:column;align-items:flex-start;gap:12px;min-width:0}
.footer-brand__mark{
  width:38px;height:38px;display:grid;place-items:center;
  font-family:var(--font-display);font-size:17px;font-weight:700;letter-spacing:.02em;
  color:var(--ink-3);
  background:linear-gradient(150deg,var(--whistle),var(--whistle-soft) 68%,var(--cyan));
  clip-path:polygon(0 0,100% 0,100% 74%,74% 100%,0 100%);
}
.footer-brand__name{
  font-family:var(--font-display);font-size:22px;font-weight:700;
  letter-spacing:.05em;color:var(--white);line-height:1.2;
}
.footer-brand__closing{max-width:34ch;font-size:14px;line-height:1.7;color:var(--mist)}

.to-top{
  display:inline-flex;align-items:center;gap:8px;
  margin-top:6px;padding:9px 14px;
  border:1px solid var(--line-strong);border-radius:2px;
  font-size:13px;letter-spacing:.04em;color:var(--mist);
  transition:border-color .18s var(--ease),color .18s var(--ease),transform .18s var(--ease);
}
.to-top:hover{border-color:var(--whistle);color:var(--whistle);transform:translateY(-1px)}
.to-top__arrow{font-family:var(--font-mono);font-size:13px}

.footer-col{min-width:0}
.footer-col__title{
  font-family:var(--font-mono);font-size:12px;font-weight:500;
  letter-spacing:.16em;text-transform:uppercase;color:var(--white);
  margin-bottom:14px;padding-bottom:10px;border-bottom:1px solid var(--line);
}
.footer-list{display:flex;flex-direction:column;gap:2px}
.footer-link{
  display:inline-flex;align-items:center;padding-block:5px;
  font-size:14px;color:var(--mist);
  transition:color .16s var(--ease),transform .16s var(--ease);
}
.footer-link::before{
  content:"";width:0;height:1px;background:var(--whistle);
  margin-right:0;transition:width .18s var(--ease),margin-right .18s var(--ease);
}
.footer-link:hover{color:var(--whistle)}
.footer-link:hover::before{width:12px;margin-right:8px}

.footer-contact{
  display:grid;gap:8px;
  margin-top:clamp(34px,4vw,56px);padding-top:clamp(22px,2.6vw,32px);
  border-top:1px solid var(--line);
}
.footer-contact__item{display:flex;flex-wrap:wrap;gap:10px;align-items:baseline;font-size:14px}
.footer-contact__key{
  min-width:64px;font-family:var(--font-mono);font-size:11px;
  letter-spacing:.12em;color:rgba(169,178,204,.65);
}
.footer-contact__val{color:var(--white);font-variant-numeric:tabular-nums}
.footer-contact__note{font-size:13px;line-height:1.7;color:var(--mist);max-width:66ch}

.footer__bottom{
  display:flex;flex-wrap:wrap;gap:10px 26px;align-items:center;
  margin-top:clamp(26px,3vw,40px);padding-top:20px;
  border-top:1px solid var(--line);
  font-family:var(--font-mono);font-size:12px;letter-spacing:.04em;color:var(--mist);
}
.footer-legal{color:var(--white)}
.footer-area{color:var(--mist)}
.footer-note{margin-left:auto;color:rgba(169,178,204,.6)}

/* ---------- 13. 滚动显现 ---------- */
.js [data-reveal]{
  opacity:0;transform:translateY(12px);
  transition:opacity .42s var(--ease),transform .42s var(--ease);
}
.js [data-reveal].is-visible{opacity:1;transform:none}

/* ---------- 14. 响应式 ---------- */
@media (min-width:640px){
  body{font-size:var(--step-3)}
}
@media (min-width:768px){
  .round-switcher{display:inline-flex}
}
@media (min-width:860px){
  .site-top__actions{display:flex;margin-left:auto}
  .site-top__actions .btn--primary{display:inline-flex}
  .footer-grid{grid-template-columns:repeat(2,minmax(0,1fr))}
}
@media (min-width:1024px){
  body{padding-left:var(--rail-w)}
  html{scroll-padding-top:96px}

  .nav-toggle{display:none}
  .site-top__actions{margin-left:auto}

  .site-rail{
    width:var(--rail-w);
    padding:20px 8px 16px;
    transform:none;visibility:visible;
    background:linear-gradient(180deg,rgba(22,32,79,.86),rgba(8,13,36,.96));
  }
  .rail-list{gap:2px}
  .rail-link{
    flex-direction:column;justify-content:center;gap:5px;
    padding:11px 2px;text-align:center;font-size:12px;
  }
  .rail-link__label{font-size:12px;letter-spacing:.02em;line-height:1.35}
  .rail-link__idx{font-size:10px}
  .rail-foot{
    text-align:center;font-size:9px;letter-spacing:.06em;line-height:1.7;
  }
  .nav-scrim{display:none}
}
@media (min-width:1080px){
  .footer-grid{grid-template-columns:1.5fr repeat(3,minmax(0,1fr))}
}
@media (min-width:1180px){
  .site-top__meta{display:flex}
  .site-top__actions .btn--ghost{display:inline-flex}
}

/* ---------- 15. 无障碍与降级 ---------- */
@media (prefers-reduced-motion: reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
  }
  .js [data-reveal]{opacity:1 !important;transform:none !important}
  .btn:hover,.card:hover,.to-top:hover{transform:none}
}