/* ==========================================================================
   AK赛场 · 共享样式表  /assets/site.css
   设计逻辑：高原夜空深蓝为底，青海湖青为唯一品牌锚点，盐湖白作反转纸面，
   警示橙红只标记伤停与重点场次，数据暖黄只出现在数字上。
   结构逻辑：88px 侧边轨道导航 + 极简文字建筑 + 宽窄章节交替。
   ========================================================================== */

/* ---------- 1. Reset ---------- */
*,*::before,*::after{box-sizing:border-box;}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth;}
body,h1,h2,h3,h4,h5,p,ul,ol,li,figure,blockquote,dl,dd{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;cursor:pointer;}
a{color:inherit;text-decoration:none;}
table{border-collapse:collapse;width:100%;}
summary{list-style:none;cursor:pointer;}
summary::-webkit-details-marker{display:none;}
:focus-visible{outline:2px solid var(--lake-bright);outline-offset:3px;}
::selection{background:var(--lake);color:#04191C;}

/* ---------- 2. Tokens ---------- */
:root{
  --night:#0B1B2B;
  --stand:#06121C;
  --lake:#12A79A;
  --lake-bright:#5DD9CD;
  --salt:#F4F7F5;
  --ink:#0F1418;
  --alert:#FF5A36;
  --data:#FFC24B;
  --slate:#5E7285;
  --rule:#C6D0D6;
  --rule-soft:rgba(198,208,214,.22);
  --rule-faint:rgba(198,208,214,.12);
  --text:rgba(244,247,245,.84);
  --text-dim:rgba(244,247,245,.62);

  --rail-w:88px;
  --rail-open:264px;

  --font-display:"Noto Serif SC","Source Han Serif SC","Songti SC",serif;
  --font-body:"PingFang SC","Microsoft YaHei","Noto Sans SC","Hiragino Sans GB",system-ui,-apple-system,sans-serif;
  --font-mono:"JetBrains Mono","IBM Plex Mono","SFMono-Regular",Consolas,"Courier New",monospace;

  --step-1:12px; --step-2:14px; --step-3:16px; --step-4:20px;
  --step-5:24px; --step-6:32px; --step-7:48px; --step-8:72px;

  --ease:cubic-bezier(.2,.7,.3,1);
  --dur:.24s;
}

/* ---------- 3. Base / 中文排版 ---------- */
body{
  min-height:100vh;
  padding-left:var(--rail-w);
  background-color:var(--night);
  background-image:
    radial-gradient(120% 80% at 82% -10%,rgba(18,167,154,.16),transparent 62%),
    radial-gradient(90% 70% at -10% 112%,rgba(6,18,28,.9),transparent 60%);
  background-attachment:fixed;
  color:var(--text);
  font-family:var(--font-body);
  font-size:var(--step-3);
  line-height:1.75;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}
body.nav-open{overflow:hidden;}

h1,h2,h3,h4{text-wrap:balance;}
strong{color:var(--salt);font-weight:600;}
hr{border:0;border-top:1px solid var(--rule-soft);margin:32px 0;}

.skip-link{
  position:fixed;top:10px;left:10px;z-index:200;
  transform:translateY(-220%);
  background:var(--lake);color:#04191C;
  padding:10px 18px;font-size:var(--step-2);font-weight:600;letter-spacing:.06em;
  transition:transform var(--dur) var(--ease);
}
.skip-link:focus,.skip-link:focus-visible{transform:translateY(0);}

/* ---------- 4. 布局容器 ---------- */
.wrap{width:100%;max-width:1200px;margin:0 auto;padding:0 32px;}
.wrap--wide{max-width:1320px;}
.wrap--narrow{max-width:760px;}

.section{padding:72px 0;position:relative;}
.section--tight{padding:40px 0;}
.section--flush{padding:0;}
.section--deep{background:var(--stand);}
.section--line{border-top:1px solid var(--rule-soft);}
.section--paper{background:var(--salt);color:var(--ink);}
.section--paper .prose,.section--paper .lede{color:rgba(15,20,24,.78);}
.section--paper .h2,.section--paper .h3,.section--paper .display{color:var(--ink);}
.section--paper .label{color:#0C6F68;background:rgba(18,167,154,.1);border-color:rgba(18,167,154,.42);}
.section--paper .legend__item,.section--paper .card__meta{color:rgba(15,20,24,.6);}
.section--paper .table th{color:rgba(15,20,24,.55);border-bottom-color:rgba(15,20,24,.2);}
.section--paper .table td{border-bottom-color:rgba(15,20,24,.12);}

[data-section]{scroll-margin-top:88px;}

/* ---------- 5. 排版组件 ---------- */
.display{
  font-family:var(--font-display);font-weight:900;
  font-size:clamp(var(--step-7),6vw,var(--step-8));
  line-height:1.08;letter-spacing:-.01em;color:var(--salt);
}
.h2{
  font-family:var(--font-display);font-weight:700;
  font-size:clamp(var(--step-5),3vw,var(--step-6));
  line-height:1.35;color:var(--salt);
}
.h3{
  font-family:var(--font-display);font-weight:600;
  font-size:var(--step-5);line-height:1.35;color:var(--salt);
}
.lede{font-size:var(--step-4);line-height:1.7;max-width:36em;color:var(--text);}
.prose{font-size:17px;line-height:1.75;max-width:38em;color:var(--text);}
.prose p + p{margin-top:1em;}
.prose ul,.prose ol{margin:1em 0;padding-left:1.2em;}
.prose li{list-style:disc;margin:.35em 0;}
.mono{font-family:var(--font-mono);letter-spacing:.02em;font-variant-numeric:tabular-nums;}
.num{font-family:var(--font-mono);font-weight:700;letter-spacing:.02em;color:var(--data);font-variant-numeric:tabular-nums;}

.label{
  position:relative;display:inline-block;
  padding:5px 13px 5px 11px;
  font-size:var(--step-1);letter-spacing:.14em;line-height:1.2;
  color:var(--lake-bright);background:rgba(18,167,154,.12);
  border:1px solid rgba(93,217,205,.5);
  clip-path:polygon(0 0,100% 0,100% calc(100% - 8px),calc(100% - 8px) 100%,0 100%);
}
.label--alert{color:var(--alert);background:rgba(255,90,54,.12);border-color:rgba(255,90,54,.55);}
.label--muted{color:var(--slate);background:rgba(94,114,133,.1);border-color:var(--rule-soft);}

/* ---------- 6. 纸张叠层与斜切 ---------- */
.paper{position:relative;border:1px solid var(--rule-soft);background:rgba(6,18,28,.55);padding:24px;}
.paper--stack::after{
  content:"";position:absolute;inset:0;z-index:-1;
  border:1px solid var(--rule-faint);transform:translate(7px,7px);pointer-events:none;
}
.section--paper .paper,.card--paper{background:#FFFFFF;border-color:rgba(15,20,24,.14);color:var(--ink);}
.slant{clip-path:polygon(0 0,100% 0,100% 62%,0 100%);}
.slant--flip{clip-path:polygon(0 0,100% 0,100% 100%,0 62%);}

/* ---------- 7. 按钮 ---------- */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  padding:12px 20px;font-size:var(--step-2);letter-spacing:.06em;line-height:1;
  color:var(--salt);background:rgba(244,247,245,.04);
  border:1px solid var(--rule-soft);
  transition:border-color var(--dur) var(--ease),color var(--dur) var(--ease),
             background-color var(--dur) var(--ease),transform var(--dur) var(--ease);
}
.btn:hover{border-color:var(--lake-bright);color:var(--lake-bright);transform:translateY(-2px);}
.btn--primary{background:var(--lake);border-color:var(--lake);color:#04191C;font-weight:600;}
.btn--primary:hover{background:var(--lake-bright);border-color:var(--lake-bright);color:#04191C;}
.btn--ghost{background:transparent;}
.btn--alert{border-color:var(--alert);color:var(--alert);}
.btn--alert:hover{background:var(--alert);color:#1A0700;}
.btn--block{width:100%;}

/* ---------- 8. 标签 / 图例 / 筛选 ---------- */
.tag{
  display:inline-flex;align-items:center;gap:6px;
  padding:3px 9px;font-size:var(--step-1);letter-spacing:.08em;line-height:1.5;
  border:1px solid var(--rule-soft);color:var(--text-dim);
}
.tag--alert{border-color:rgba(255,90,54,.6);color:var(--alert);background:rgba(255,90,54,.1);}
.tag--data{border-color:rgba(255,194,75,.5);color:var(--data);background:rgba(255,194,75,.08);}

.legend{display:flex;flex-wrap:wrap;gap:14px 22px;align-items:center;}
.legend__item{display:flex;align-items:center;gap:8px;font-size:var(--step-2);color:var(--text-dim);}
.legend__swatch{width:14px;height:14px;flex:none;}
.legend__swatch--lake{background:var(--lake);}
.legend__swatch--alert{background:var(--alert);}
.legend__swatch--data{background:var(--data);}
.legend__swatch--rule{border:1px solid var(--rule);background:transparent;}

.filter{display:flex;flex-wrap:wrap;gap:8px;}
.filter__btn{
  padding:8px 15px;font-size:var(--step-1);letter-spacing:.1em;
  border:1px solid var(--rule-soft);color:var(--text-dim);
  transition:border-color var(--dur) var(--ease),color var(--dur) var(--ease),
             background-color var(--dur) var(--ease);
}
.filter__btn:hover{border-color:var(--lake-bright);color:var(--lake-bright);}
.filter__btn[aria-pressed="true"]{background:var(--lake);border-color:var(--lake);color:#04191C;font-weight:600;}
[data-filter-tag][hidden],[data-filter-item][hidden]{display:none;}

/* ---------- 9. 卡片 / 表格 / 折叠 ---------- */
.card{
  position:relative;padding:20px;
  border:1px solid var(--rule-soft);background:rgba(6,18,28,.55);
  transition:border-color var(--dur) var(--ease),transform var(--dur) var(--ease);
}
.card:hover{border-color:rgba(93,217,205,.5);transform:translateY(-2px);}
.card--paper{background:#FFFFFF;color:var(--ink);border-color:rgba(15,20,24,.14);}
.card--alert::before{content:"";position:absolute;left:0;top:0;bottom:0;width:3px;background:var(--alert);}
.card__meta{font-size:var(--step-2);color:var(--text-dim);letter-spacing:.04em;}
.card__title{font-family:var(--font-display);font-size:var(--step-4);font-weight:600;line-height:1.4;color:var(--salt);}
.card--paper .card__title{color:var(--ink);}
.card__foot{margin-top:16px;padding-top:12px;border-top:1px solid var(--rule-faint);font-size:var(--step-2);color:var(--text-dim);}

.table{width:100%;font-size:var(--step-2);}
.table th{
  text-align:left;padding:10px 12px;font-weight:500;
  font-size:var(--step-1);letter-spacing:.14em;color:var(--text-dim);
  border-bottom:1px solid var(--rule-soft);white-space:nowrap;
}
.table td{padding:12px;border-bottom:1px solid var(--rule-faint);vertical-align:top;}
.table tbody tr:hover{background:rgba(18,167,154,.07);}

.fold{border:1px solid var(--rule-soft);background:rgba(6,18,28,.5);}
.fold + .fold{margin-top:10px;}
.fold__head{
  display:flex;align-items:center;justify-content:space-between;gap:16px;
  padding:16px 18px;font-size:var(--step-3);color:var(--salt);
}
.fold__head::after{content:"＋";font-family:var(--font-mono);color:var(--lake);flex:none;}
.fold[open] .fold__head::after{content:"－";}
.fold[open] .fold__head{border-bottom:1px solid var(--rule-faint);}
.fold__body{padding:16px 18px;font-size:15px;line-height:1.75;color:var(--text);}

.steps{counter-reset:step;}
.steps__item{
  position:relative;margin-left:16px;padding:0 0 24px 52px;
  border-left:1px solid var(--rule-soft);
}
.steps__item::before{
  counter-increment:step;content:counter(step,decimal-leading-zero);
  position:absolute;left:-17px;top:0;
  width:32px;height:32px;display:grid;place-items:center;
  background:var(--stand);border:1px solid var(--lake);color:var(--lake-bright);
  font-family:var(--font-mono);font-size:var(--step-1);
}
.steps__item:last-child{border-left-color:transparent;padding-bottom:0;}

/* ---------- 10. 坐标索引 / 面包屑 ---------- */
.coord-list{border-left:1px solid var(--rule-soft);}
.coord-list__item a{
  display:flex;gap:12px;align-items:baseline;
  margin-left:-1px;padding:9px 0 9px 14px;
  border-left:2px solid transparent;
  font-size:var(--step-2);color:var(--text-dim);
  transition:color var(--dur) var(--ease),border-color var(--dur) var(--ease);
}
.coord-list__item a:hover{color:var(--salt);border-left-color:var(--lake-bright);}
.coord-list__item a.is-active{color:var(--lake-bright);border-left-color:var(--lake);}
.coord-list__idx{font-family:var(--font-mono);font-size:var(--step-1);color:var(--slate);flex:none;}

.breadcrumb{display:flex;flex-wrap:wrap;gap:8px;font-size:var(--step-1);letter-spacing:.06em;color:var(--slate);}
.breadcrumb a:hover{color:var(--lake-bright);}
.breadcrumb__sep{color:rgba(94,114,133,.6);}
.breadcrumb [aria-current="page"]{color:var(--salt);}

/* ---------- 11. 图片容器（页面阶段投放） ---------- */
.media{
  position:relative;display:block;overflow:hidden;
  border:1px solid var(--rule-soft);
  background-color:var(--stand);
  background-image:linear-gradient(160deg,#0B1B2B 0%,#12303F 55%,#06121C 100%);
}
.media::after{
  content:"";position:absolute;inset:0;z-index:1;pointer-events:none;
  background:linear-gradient(180deg,rgba(11,27,43,0) 42%,rgba(6,18,28,.78) 100%);
}
.media img,.media video{width:100%;height:100%;object-fit:cover;filter:saturate(.92) contrast(1.05);}
.media--16x9{aspect-ratio:16/9;}
.media--4x3{aspect-ratio:4/3;}
.media--3x4{aspect-ratio:3/4;}
.media--1x1{aspect-ratio:1/1;}
.media--min{min-height:200px;}
.media--paper{border-color:rgba(15,20,24,.16);}
.media__ph{
  position:absolute;inset:0;
  background-image:linear-gradient(rgba(93,217,205,.09) 1px,transparent 1px),
                   linear-gradient(90deg,rgba(93,217,205,.09) 1px,transparent 1px);
  background-size:40px 40px;
}
.media__caption{
  position:absolute;left:0;bottom:0;z-index:2;
  padding:14px 16px;font-size:var(--step-1);letter-spacing:.06em;color:rgba(244,247,245,.86);
}
.media__tag{position:absolute;top:12px;left:12px;z-index:2;}

/* ---------- 12. 栅格 ---------- */
.grid{display:grid;gap:20px;}
.grid--2{grid-template-columns:repeat(2,minmax(0,1fr));}
.grid--3{grid-template-columns:repeat(3,minmax(0,1fr));}
.grid--4{grid-template-columns:repeat(4,minmax(0,1fr));}
.grid--cards{grid-template-columns:repeat(auto-fill,minmax(240px,1fr));}

/* ---------- 13. 页头：侧边轨道导航 ---------- */
.site-header{position:fixed;top:0;left:0;z-index:120;width:0;height:0;}

.rail{
  position:fixed;top:0;left:0;bottom:0;z-index:120;
  width:var(--rail-w);
  display:flex;flex-direction:column;gap:26px;
  padding:22px 0 22px;
  background:var(--stand);
  border-right:1px solid rgba(198,208,214,.16);
  overflow:hidden;
  transition:width var(--dur) var(--ease);
}
.rail:hover,.rail:focus-within{width:var(--rail-open);}

.brand{display:flex;align-items:center;gap:14px;padding-left:24px;flex:none;}
.brand__mark{
  width:40px;height:40px;flex:none;
  display:grid;place-items:center;
  background:rgba(18,167,154,.12);border:1px solid var(--lake);
  color:var(--lake-bright);font-family:var(--font-mono);
  font-size:var(--step-3);font-weight:700;letter-spacing:.02em;
  clip-path:polygon(0 0,100% 0,100% 74%,74% 100%,0 100%);
}
.brand__text{display:flex;flex-direction:column;gap:2px;white-space:nowrap;opacity:0;transform:translateX(-6px);transition:opacity var(--dur) var(--ease),transform var(--dur) var(--ease);}
.brand__name{font-family:var(--font-display);font-weight:700;font-size:18px;line-height:1.3;color:var(--salt);}
.brand__line{font-size:var(--step-1);letter-spacing:.12em;color:var(--slate);}
.rail:hover .brand__text,.rail:focus-within .brand__text{opacity:1;transform:none;}

.nav-toggle{display:none;}

.site-nav{
  display:flex;flex-direction:column;gap:14px;flex:1;min-height:0;
  padding:0 24px;overflow-y:auto;overflow-x:hidden;
}
.site-nav__title{font-size:var(--step-1);letter-spacing:.16em;color:var(--slate);white-space:nowrap;opacity:0;transition:opacity var(--dur) var(--ease);}
.rail:hover .site-nav__title,.rail:focus-within .site-nav__title{opacity:1;}
.site-nav__list{display:flex;flex-direction:column;gap:2px;}
.site-nav__item{display:block;}
.site-nav__link{
  display:flex;align-items:center;gap:12px;
  margin-left:-1px;padding:10px 0 10px 11px;
  border-left:2px solid transparent;
  font-size:15px;color:var(--text-dim);
  transition:color var(--dur) var(--ease),border-color var(--dur) var(--ease);
}
.site-nav__idx{font-family:var(--font-mono);font-size:var(--step-1);color:var(--slate);flex:none;transition:color var(--dur) var(--ease);}
.site-nav__text{white-space:nowrap;opacity:0;transform:translateX(-6px);transition:opacity .18s var(--ease),transform var(--dur) var(--ease);}
.rail:hover .site-nav__text,.rail:focus-within .site-nav__text{opacity:1;transform:none;}
.site-nav__link:hover{color:var(--salt);}
.site-nav__link:hover .site-nav__idx{color:var(--lake-bright);}
.site-nav__link[aria-current="page"]{color:var(--salt);border-left-color:var(--lake);}
.site-nav__link[aria-current="page"] .site-nav__idx{color:var(--lake);}

.site-nav__foot{
  display:flex;flex-direction:column;gap:10px;margin-top:auto;padding-top:18px;
  border-top:1px solid rgba(198,208,214,.16);
  opacity:0;visibility:hidden;transition:opacity var(--dur) var(--ease);
}
.rail:hover .site-nav__foot,.rail:focus-within .site-nav__foot{opacity:1;visibility:visible;}
.site-nav__note{font-size:var(--step-1);line-height:1.7;color:var(--slate);white-space:normal;}

.progress{
  position:fixed;top:0;left:var(--rail-w);right:0;height:2px;z-index:130;
  background:rgba(198,208,214,.12);
}
.progress__bar{display:block;height:100%;width:0;background:linear-gradient(90deg,var(--lake),var(--lake-bright));}

/* ---------- 14. 页脚 ---------- */
.site-footer{
  position:relative;
  margin-top:72px;
  padding-top:52px;
  background:var(--stand);
  border-top:1px solid var(--rule-soft);
}
.site-footer__cut{
  position:absolute;top:-1px;left:0;width:min(46%,560px);height:3px;
  background:var(--lake);
  clip-path:polygon(0 0,100% 0,calc(100% - 26px) 100%,0 100%);
}
.site-footer__inner{
  display:grid;gap:36px;
  grid-template-columns:minmax(220px,1.1fr) repeat(3,minmax(150px,.8fr));
  padding-bottom:44px;
}
.site-footer__brand{display:flex;flex-direction:column;gap:8px;}
.site-footer__mark{font-family:var(--font-display);font-weight:900;font-size:var(--step-5);line-height:1.2;color:var(--salt);}
.site-footer__tagline{font-size:var(--step-2);letter-spacing:.12em;color:var(--lake-bright);}
.site-footer__desc{font-size:var(--step-2);color:var(--slate);letter-spacing:.04em;}

.foot-col{display:flex;flex-direction:column;gap:14px;min-width:0;}
.foot-col__title{font-size:var(--step-1);letter-spacing:.16em;color:var(--text-dim);padding-bottom:10px;border-bottom:1px solid rgba(198,208,214,.16);}
.foot-col__list{display:flex;flex-direction:column;gap:9px;font-size:var(--step-2);}
.foot-col__list a{color:var(--text-dim);transition:color var(--dur) var(--ease);}
.foot-col__list a:hover{color:var(--lake-bright);}
.foot-col__list a[aria-current="page"]{color:var(--lake);}
.foot-col__list--plain li{color:var(--text);line-height:1.7;word-break:break-word;}
.foot-mono{font-family:var(--font-mono);font-size:var(--step-2);letter-spacing:.02em;color:var(--salt);}
.foot-note{font-size:var(--step-1);line-height:1.7;color:var(--slate);}

.site-footer__bar{border-top:1px solid rgba(198,208,214,.14);}
.site-footer__bar-inner{
  display:flex;flex-wrap:wrap;gap:12px 24px;
  align-items:center;justify-content:space-between;
  padding-top:18px;padding-bottom:18px;
}
.site-footer__copy{font-size:var(--step-1);color:var(--slate);line-height:1.8;}
.site-footer__icp{font-family:var(--font-mono);font-size:var(--step-1);letter-spacing:.04em;color:var(--slate);}

/* ---------- 15. 滚动显现 ---------- */
.js-reveal [data-reveal]{opacity:0;transform:translateY(12px);}
.js-reveal [data-reveal].is-in{
  opacity:1;transform:none;
  transition:opacity .24s var(--ease),transform .24s var(--ease);
}

/* ---------- 16. 响应式 ---------- */
@media (max-width:1100px){
  .site-footer__inner{grid-template-columns:repeat(2,minmax(0,1fr));}
  .site-footer__brand{grid-column:1 / -1;}
}

@media (max-width:960px){
  .grid--4{grid-template-columns:repeat(2,minmax(0,1fr));}
  .grid--3{grid-template-columns:repeat(2,minmax(0,1fr));}
}

@media (max-width:900px){
  :root{--rail-w:0px;}
  body{padding-left:0;padding-top:56px;background-attachment:scroll;}
  [data-section]{scroll-margin-top:72px;}

  .rail{
    top:0;left:0;right:0;bottom:auto;width:100%;height:56px;
    flex-direction:row;align-items:center;justify-content:space-between;
    gap:0;padding:0 16px;overflow:visible;
    border-right:0;border-bottom:1px solid rgba(198,208,214,.16);
  }
  .rail:hover,.rail:focus-within{width:100%;}
  .brand{padding-left:0;}
  .brand__text{opacity:1;transform:none;}
  .brand__line{display:none;}

  .nav-toggle{
    display:inline-flex;align-items:center;gap:10px;
    padding:8px 12px;font-size:var(--step-1);letter-spacing:.12em;
    color:var(--salt);border:1px solid var(--rule-soft);
  }
  .nav-toggle__bars{display:grid;gap:4px;width:18px;}
  .nav-toggle__bars span{display:block;height:1px;background:currentColor;transition:transform var(--dur) var(--ease),opacity var(--dur) var(--ease);}
  .nav-toggle__bars span:nth-child(2){width:70%;}
  .nav-toggle[aria-expanded="true"]{border-color:var(--lake);color:var(--lake-bright);}
  .nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(1){transform:translateY(5px) rotate(45deg);}
  .nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(2){opacity:0;}
  .nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(3){transform:translateY(-5px) rotate(-45deg);}

  .site-nav{
    position:fixed;top:56px;left:0;right:0;bottom:0;width:100%;
    display:flex;flex-direction:column;gap:18px;
    padding:26px 20px 40px;overflow-y:auto;
    background:var(--stand);border-top:1px solid rgba(198,208,214,.14);
    transform:translateX(-100%);visibility:hidden;z-index:110;
    transition:transform .26s var(--ease),visibility .26s linear;
  }
  .site-nav[data-open]{transform:translateX(0);visibility:visible;}
  .site-nav__title{opacity:1;}
  .site-nav__list{gap:0;}
  .site-nav__link{padding:14px 0 14px 11px;font-size:17px;border-bottom:1px solid var(--rule-faint);}
  .site-nav__text,.site-nav__foot{opacity:1;transform:none;visibility:visible;}
  .site-nav__foot{border-top:0;padding-top:20px;}

  .progress{left:0;}
  .wrap{padding:0 20px;}
  .section{padding:52px 0;}
  .display{font-size:clamp(34px,10vw,var(--step-7));}
}

@media (max-width:720px){
  .grid--2,.grid--3,.grid--4{grid-template-columns:1fr;}
  .site-footer__inner{grid-template-columns:1fr;gap:28px;padding-bottom:32px;}
  .site-footer{margin-top:52px;padding-top:40px;}
  .table th,.table td{padding:10px 8px;}
}

@media (max-width:420px){
  .brand__name{font-size:16px;}
  .nav-toggle__label{display:none;}
}

/* ---------- 17. 动效与可访问性偏好 ---------- */
@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-reveal [data-reveal]{opacity:1 !important;transform:none !important;}
  .btn:hover,.card:hover{transform:none;}
}