/* =========================================================
   安博体育手机版 · 共享样式 /assets/site.css
   高原竞技数据舱：深空底 / 精密网格 / 青蓝橙红撞色
   ========================================================= */

/* ---------- 01 重置 ---------- */
*,*::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,table{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{cursor:pointer;}
:focus-visible{outline:2px solid #B6FF3C;outline-offset:3px;border-radius:2px;}
::selection{background:#FF5A1F;color:#120704;}

/* ---------- 02 变量与基座 ---------- */
:root{
  --bg:#0A0E12;
  --panel:#131B23;
  --line:#24313C;
  --snow:#E9EFF4;
  --paper:#F4F7F9;
  --orange:#FF5A1F;
  --cyan:#29A8BF;
  --lime:#B6FF3C;
  --index:#8B98A5;
  --dark-orange:#B33A0F;
  --ink:#0E1418;
  --rail-w:88px;
  --bar-h:60px;
  --maxw:1400px;
  --gutter:clamp(18px,4.4vw,64px);
  --ease:cubic-bezier(.2,.7,.2,1);
  --font-sans:"PingFang SC","Hiragino Sans GB","Source Han Sans SC","Noto Sans SC","Microsoft YaHei",system-ui,-apple-system,sans-serif;
  --font-mono:ui-monospace,SFMono-Regular,Menlo,Consolas,"Courier New",monospace;
}
body{
  min-height:100vh;
  background:var(--bg);
  color:var(--snow);
  font-family:var(--font-sans);
  font-size:16px;
  line-height:1.75;
  letter-spacing:.01em;
  -webkit-font-smoothing:antialiased;
}
body::before{
  content:"";
  position:fixed;
  inset:0;
  z-index:0;
  pointer-events:none;
  background-image:
    linear-gradient(to right,rgba(36,49,60,.55) 1px,transparent 1px),
    linear-gradient(to bottom,rgba(36,49,60,.55) 1px,transparent 1px);
  background-size:88px 88px;
  opacity:.42;
}
main,.site-footer{position:relative;z-index:1;}
body.is-nav-open{overflow:hidden;}

/* ---------- 03 排版 ---------- */
.h-display{font-size:clamp(42px,8.4vw,112px);font-weight:200;line-height:1.02;letter-spacing:-.02em;}
.h-section{font-size:clamp(26px,4.2vw,52px);font-weight:200;line-height:1.06;letter-spacing:-.01em;}
.h-sub{font-size:clamp(18px,2vw,23px);font-weight:500;line-height:1.35;letter-spacing:.01em;}
.eyebrow{display:inline-flex;align-items:center;gap:10px;font-size:11px;font-weight:500;letter-spacing:.18em;color:var(--cyan);text-transform:uppercase;}
.eyebrow::before{content:"";width:22px;height:1px;background:var(--cyan);}
.lede{font-size:clamp(15.5px,1.5vw,18.5px);line-height:1.75;color:#A9B8C5;max-width:62ch;}
.index-note{font-size:11px;letter-spacing:.18em;color:var(--index);}
.mono{font-family:var(--font-mono);}
.num{font-family:var(--font-mono);font-weight:700;font-variant-numeric:tabular-nums;letter-spacing:-.02em;}
.num-key{font-family:var(--font-mono);font-weight:700;font-variant-numeric:tabular-nums;color:#0A1207;background:var(--lime);padding:0 .22em;border-radius:2px;}
.num-accent{font-family:var(--font-mono);font-weight:700;font-variant-numeric:tabular-nums;color:var(--orange);}
.prose{max-width:720px;font-size:16.5px;line-height:1.85;color:#B7C4D0;}
.prose p{margin-bottom:20px;}
.prose h2{font-size:clamp(20px,2.4vw,28px);font-weight:500;color:var(--snow);margin:38px 0 14px;letter-spacing:.01em;}
.prose h3{font-size:18px;font-weight:600;color:var(--snow);margin:28px 0 10px;}
.prose ul{display:flex;flex-direction:column;gap:10px;margin:0 0 22px;}
.prose ul li{position:relative;padding-left:18px;}
.prose ul li::before{content:"";position:absolute;left:0;top:.78em;width:8px;height:1px;background:var(--lime);}
[data-chapter]{scroll-margin-top:calc(var(--bar-h) + 18px);}

/* ---------- 04 布局 ---------- */
.wrap{width:100%;max-width:var(--maxw);margin-inline:auto;padding-inline:var(--gutter);}
.section{padding-block:clamp(44px,6.4vw,104px);}
.section--tight{padding-block:clamp(26px,3.6vw,54px);}
.grid{display:grid;gap:clamp(16px,2vw,24px);}
.grid--2{grid-template-columns:repeat(auto-fit,minmax(260px,1fr));}
.grid--3{grid-template-columns:repeat(auto-fit,minmax(220px,1fr));}
.stack{display:flex;flex-direction:column;gap:clamp(10px,1.4vw,18px);}
.rule{height:1px;border:0;background:var(--line);}
.rule--ticks{
  height:8px;
  background-color:transparent;
  background-image:repeating-linear-gradient(to right,var(--line) 0 1px,transparent 1px 14px);
  background-size:14px 5px;
  background-position:left bottom;
  background-repeat:repeat-x;
  border-bottom:1px solid var(--line);
}
.frame{
  position:relative;
  border:1px solid var(--line);
  border-radius:2px;
  background:linear-gradient(180deg,rgba(19,27,35,.82),rgba(10,14,18,.55));
  padding:clamp(20px,4vw,54px);
}
.frame::before,.frame::after{content:"";position:absolute;width:15px;height:15px;border:1px solid var(--cyan);opacity:.85;}
.frame::before{top:-1px;left:-1px;border-right:0;border-bottom:0;}
.frame::after{bottom:-1px;right:-1px;border-left:0;border-top:0;}

/* ---------- 05 按钮与标签 ---------- */
.btn{
  display:inline-flex;align-items:center;gap:10px;
  padding:13px 22px;
  font-size:14px;font-weight:500;letter-spacing:.06em;
  border:1px solid var(--line);border-radius:2px;
  background:transparent;color:var(--snow);
  transition:background .2s var(--ease),color .2s var(--ease),border-color .2s var(--ease),transform .2s var(--ease);
}
.btn:hover{border-color:var(--cyan);color:#fff;}
.btn--primary{background:var(--orange);border-color:var(--orange);color:#140602;font-weight:600;}
.btn--primary:hover{background:#FF7A45;border-color:#FF7A45;color:#140602;transform:translateY(-2px);}
.btn--ghost{border-color:var(--cyan);color:var(--cyan);}
.btn--ghost:hover{background:rgba(41,168,191,.12);color:#fff;}
.btn--quiet{border-color:transparent;padding-inline:0;color:var(--cyan);}
.btn--block{width:100%;justify-content:center;}
.tag{
  display:inline-flex;align-items:center;gap:7px;
  padding:4px 10px;border:1px solid var(--line);border-radius:2px;
  font-size:12.5px;font-weight:500;letter-spacing:.06em;
  color:var(--cyan);background:rgba(41,168,191,.06);
}
.tag::before{content:"";width:6px;height:6px;border-radius:50%;background:var(--lime);}
.tag--live{color:var(--lime);border-color:rgba(182,255,60,.42);}
.tag--quiet{color:var(--index);}
.tag--quiet::before{background:var(--line);}
.chip{
  display:inline-flex;align-items:center;gap:8px;
  padding:8px 14px;border:1px solid var(--line);border-radius:2px;
  font-size:13px;color:#A9B8C5;background:rgba(19,27,35,.6);
  transition:border-color .2s var(--ease),color .2s var(--ease),background .2s var(--ease);
}
.chip:hover{border-color:var(--cyan);color:var(--snow);}
.chip[aria-pressed="true"],.chip[data-active="true"]{border-color:var(--orange);color:var(--orange);background:rgba(255,90,31,.08);}
.chipline{display:flex;flex-wrap:wrap;gap:10px;}

/* ---------- 06 面包屑 ---------- */
.breadcrumb{font-size:11px;letter-spacing:.16em;color:var(--index);}
.breadcrumb ol{display:flex;flex-wrap:wrap;align-items:center;gap:8px;}
.breadcrumb li:not(:last-child)::after{content:"/";margin-left:8px;color:var(--line);}
.breadcrumb a{color:var(--index);transition:color .2s var(--ease);}
.breadcrumb a:hover{color:var(--cyan);}
.breadcrumb [aria-current="page"]{color:var(--snow);}

/* ---------- 07 卡片 / 统计 / 表格 / 折叠 ---------- */
.card{
  position:relative;display:flex;flex-direction:column;gap:12px;
  background:var(--panel);border:1px solid var(--line);border-radius:2px;
  padding:clamp(18px,2.2vw,26px);
  transition:border-color .24s var(--ease),transform .24s var(--ease),background .24s var(--ease);
}
.card:hover{border-color:rgba(41,168,191,.65);transform:translateY(-2px);}
.card__kicker{font-size:11px;letter-spacing:.18em;color:var(--index);}
.card__title{font-size:clamp(17px,1.7vw,20px);font-weight:600;line-height:1.4;color:var(--snow);}
.card__text{font-size:14.5px;line-height:1.8;color:#95A4B1;}
.card__meta{display:flex;flex-wrap:wrap;gap:8px 14px;margin-top:auto;font-size:11px;letter-spacing:.14em;color:var(--index);}
.stat{display:flex;flex-direction:column;gap:6px;}
.stat__num{font-family:var(--font-mono);font-weight:700;font-variant-numeric:tabular-nums;font-size:clamp(30px,4.6vw,54px);line-height:1;letter-spacing:-.02em;color:var(--snow);}
.stat__num--accent{color:var(--orange);}
.stat__label{font-size:12.5px;letter-spacing:.08em;color:var(--index);}
.table-wrap{overflow-x:auto;border:1px solid var(--line);border-radius:2px;background:var(--panel);}
.table{min-width:520px;font-size:14.5px;}
.table th,.table td{padding:12px 16px;text-align:left;border-bottom:1px solid var(--line);}
.table th{font-size:11px;font-weight:500;letter-spacing:.16em;color:var(--index);background:rgba(10,14,18,.5);}
.table td{color:#B7C4D0;}
.table tbody tr:last-child td{border-bottom:0;}
.disclosure{border:1px solid var(--line);border-radius:2px;background:var(--panel);}
.disclosure + .disclosure{margin-top:10px;}
.disclosure > summary{
  display:flex;align-items:center;justify-content:space-between;gap:16px;
  padding:16px 18px;font-size:16px;font-weight:500;color:var(--snow);list-style:none;
}
.disclosure > summary::-webkit-details-marker{display:none;}
.disclosure > summary::after{content:"+";font-family:var(--font-mono);font-size:16px;color:var(--cyan);}
.disclosure[open] > summary::after{content:"–";color:var(--orange);}
.disclosure__body{padding:0 18px 18px;font-size:15px;line-height:1.85;color:#9FAEBB;}

/* ---------- 08 章节索引 ---------- */
.toc__list{display:flex;flex-direction:column;gap:2px;}
.toc__link{
  display:block;padding:8px 0 8px 14px;
  border-left:1px solid var(--line);
  font-size:13px;color:var(--index);
  transition:color .2s var(--ease),border-color .2s var(--ease),padding-left .2s var(--ease);
}
.toc__link:hover{color:var(--snow);}
.toc__link[aria-current="true"]{color:var(--orange);border-left-color:var(--orange);padding-left:18px;}

/* ---------- 09 图片容器 ---------- */
.media{
  position:relative;overflow:hidden;
  aspect-ratio:16 / 9;
  border:1px solid var(--line);border-radius:2px;
  background:linear-gradient(135deg,#0F2530 0%,#2A1410 100%);
}
.media > img,.media > picture > img{width:100%;height:100%;object-fit:cover;}
.media::after{
  content:"";position:absolute;inset:0;pointer-events:none;
  background:linear-gradient(180deg,rgba(41,168,191,.20),rgba(255,90,31,.22));
  mix-blend-mode:screen;
}
.media--4x3{aspect-ratio:4 / 3;}
.media--1x1{aspect-ratio:1 / 1;}
.media--3x4{aspect-ratio:3 / 4;}
.media--21x9{aspect-ratio:21 / 9;}
.media__caption{
  position:absolute;left:0;bottom:0;z-index:2;
  padding:8px 12px;font-size:11px;letter-spacing:.14em;color:var(--snow);
  background:rgba(10,14,18,.78);border-top:1px solid var(--line);
}

/* ---------- 10 浅色阅读分区 ---------- */
.zone--paper{background:var(--paper);color:var(--ink);}
.zone--paper .h-display,.zone--paper .h-section,.zone--paper .h-sub,.zone--paper h2,.zone--paper h3{color:#0B1014;}
.zone--paper .lede{color:#3E4C57;}
.zone--paper .prose{color:#26313A;}
.zone--paper .eyebrow{color:var(--dark-orange);}
.zone--paper .eyebrow::before{background:var(--dark-orange);}
.zone--paper a:not(.btn){color:var(--dark-orange);}
.zone--paper .card{background:#fff;border-color:#D2DCE3;}
.zone--paper .card__title{color:#0B1014;}
.zone--paper .card__text{color:#4B5A65;}
.zone--paper .card__kicker,.zone--paper .card__meta{color:#6C7B87;}
.zone--paper .tag{color:var(--dark-orange);border-color:#CFDAE2;background:#fff;}
.zone--paper .table-wrap{background:#fff;border-color:#D2DCE3;}
.zone--paper .table th{background:#E7EEF3;color:#4B5A65;}
.zone--paper .table th,.zone--paper .table td{border-color:#D2DCE3;}
.zone--paper .table td{color:#26313A;}
.zone--paper .rule,.zone--paper .rule--ticks{border-color:#CFDAE2;}
.zone--paper .rule{background:#CFDAE2;}
.zone--paper .rule--ticks{background-color:transparent;background-image:repeating-linear-gradient(to right,#CFDAE2 0 1px,transparent 1px 14px);}
.zone--paper .index-note{color:#6C7B87;}
.zone--paper .disclosure{background:#fff;border-color:#D2DCE3;}
.zone--paper .disclosure > summary{color:#0B1014;}
.zone--paper .disclosure__body{color:#3E4C57;}

/* ---------- 11 头部：移动端粘性条 + 抽屉 ---------- */
.site-header{
  position:sticky;top:0;z-index:90;
  display:flex;align-items:center;justify-content:space-between;gap:12px;
  height:var(--bar-h);
  padding:0 var(--gutter);
  background:linear-gradient(180deg,#0C1218,#0A0E12);
  border-bottom:1px solid var(--line);
}
.skip-link{
  position:fixed;top:8px;left:8px;z-index:120;
  padding:10px 16px;border-radius:2px;
  background:var(--lime);color:#08110A;
  font-size:13px;letter-spacing:.08em;
  transform:translateY(-160%);
  transition:transform .18s var(--ease);
}
.skip-link:focus{transform:translateY(0);}
.brand{display:flex;align-items:center;gap:10px;min-width:0;}
.brand__mark{
  display:grid;place-items:center;flex:0 0 34px;
  width:34px;height:34px;border-radius:2px;
  border:1px solid var(--line);
  background:linear-gradient(135deg,rgba(41,168,191,.28),rgba(255,90,31,.26));
  font-size:11px;letter-spacing:.02em;color:var(--snow);
}
.brand__text{display:flex;flex-direction:column;min-width:0;}
.brand__name{font-size:15px;font-weight:600;line-height:1.3;letter-spacing:.02em;color:var(--snow);white-space:nowrap;}
.brand__desc{
  max-width:54vw;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;
  font-size:11px;line-height:1.4;letter-spacing:.14em;color:var(--index);
}
.nav-toggle{
  position:relative;z-index:96;
  display:inline-flex;align-items:center;gap:8px;
  padding:8px 10px;border:1px solid var(--line);border-radius:2px;color:var(--snow);
  transition:border-color .2s var(--ease);
}
.nav-toggle:hover{border-color:var(--cyan);}
.nav-toggle__grid{display:grid;grid-template-columns:repeat(2,7px);grid-template-rows:repeat(2,7px);gap:3px;}
.nav-toggle__grid i{width:7px;height:7px;background:var(--cyan);transition:background .2s var(--ease);}
.nav-toggle__label{font-size:12px;letter-spacing:.16em;color:var(--index);}
.site-header[data-open="true"] .nav-toggle__grid i{background:var(--orange);}
.site-header[data-open="true"] .nav-toggle__label{color:var(--snow);}

.nav{
  position:fixed;top:0;right:0;z-index:94;
  display:flex;flex-direction:column;gap:20px;
  width:min(90vw,380px);height:100vh;height:100dvh;
  padding:calc(var(--bar-h) + 20px) 22px 32px;
  background:#0B1218;
  border-left:1px solid var(--line);
  transform:translateX(102%);
  visibility:hidden;
  overflow-y:auto;
  overscroll-behavior:contain;
  transition:transform .32s var(--ease),visibility .32s linear;
}
.site-header[data-open="true"] .nav{transform:translateX(0);visibility:visible;}
.nav__kicker{
  padding-bottom:12px;border-bottom:1px solid var(--line);
  font-size:11px;letter-spacing:.18em;color:var(--index);
}
.nav__list{display:flex;flex-direction:column;}
.nav__item{border-bottom:1px solid var(--line);}
.nav__link{
  display:flex;align-items:center;gap:14px;
  padding:15px 2px;
  font-size:19px;font-weight:300;letter-spacing:.04em;color:var(--snow);
  transition:color .2s var(--ease),padding .2s var(--ease);
}
.nav__link:hover{color:#fff;padding-left:6px;}
.nav__num{width:24px;font-family:var(--font-mono);font-size:11px;letter-spacing:.12em;color:var(--index);}
.nav__text{flex:1;}
.nav__tick{width:18px;height:1px;background:var(--line);transition:width .24s var(--ease),background .24s var(--ease);}
.nav__link:hover .nav__tick{width:30px;background:var(--cyan);}
.nav__link[aria-current="page"]{color:var(--orange);}
.nav__link[aria-current="page"] .nav__num{color:var(--lime);}
.nav__link[aria-current="page"] .nav__tick{width:36px;background:var(--orange);}
.nav__actions{
  display:flex;flex-direction:column;gap:12px;align-items:stretch;
  margin-top:auto;padding-top:18px;border-top:1px solid var(--line);
}
.nav__util{font-size:13px;letter-spacing:.08em;color:var(--cyan);transition:color .2s var(--ease);}
.nav__util:hover{color:#fff;}
.nav-scrim{
  position:fixed;inset:0;z-index:92;
  background:rgba(5,8,11,.74);
  opacity:0;visibility:hidden;
  transition:opacity .3s var(--ease),visibility .3s linear;
}
.site-header[data-open="true"] .nav-scrim{opacity:1;visibility:visible;}
.scroll-progress{
  position:fixed;top:0;left:0;right:0;z-index:100;height:2px;
  background:rgba(36,49,60,.6);pointer-events:none;
}
.scroll-progress__bar{
  display:block;width:100%;height:100%;
  transform:scaleX(0);transform-origin:0 50%;
  background:linear-gradient(90deg,var(--cyan),var(--orange));
  transition:transform .12s linear;
}

/* ---------- 12 页脚 ---------- */
.site-footer{
  margin-top:clamp(40px,7vw,110px);
  background:linear-gradient(180deg,#0B1116,#07090C);
  border-top:1px solid var(--line);
  color:var(--index);
}
.site-footer::before{
  content:"";display:block;height:1px;
  background:linear-gradient(90deg,var(--cyan),transparent 42%,transparent 58%,var(--orange));
  opacity:.75;
}
.footer__grid{display:grid;gap:34px;padding:clamp(34px,5vw,68px) 0 clamp(24px,3vw,40px);}
.footer__brand{display:flex;flex-direction:column;gap:12px;max-width:40ch;}
.footer__name{font-size:18px;font-weight:600;letter-spacing:.04em;color:var(--snow);}
.footer__summary{font-size:14px;line-height:1.85;color:#93A2AF;}
.footer__stamp{font-size:11px;letter-spacing:.16em;color:var(--cyan);}
.footer__coltitle{margin-bottom:14px;font-size:11px;font-weight:500;letter-spacing:.18em;color:var(--index);}
.footer__links{display:flex;flex-direction:column;gap:10px;}
.footer__links a{
  font-size:14px;color:#C3CEDA;
  transition:color .2s var(--ease),padding-left .2s var(--ease);
}
.footer__links a:hover{color:var(--orange);padding-left:4px;}
.footer__bar{
  display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;
  gap:12px 26px;padding:18px 0 34px;
  font-size:12.5px;color:var(--index);
}
.footer__legal{letter-spacing:.06em;}
.footer__contact{color:#93A2AF;}
.footer__note{font-size:12px;color:#71808D;}
.footer__top{
  display:inline-flex;align-items:center;gap:8px;
  padding:9px 14px;border:1px solid var(--line);border-radius:2px;
  font-size:12px;letter-spacing:.14em;color:var(--snow);
  transition:border-color .2s var(--ease),color .2s var(--ease);
}
.footer__top:hover{border-color:var(--orange);color:var(--orange);}
.to-top{
  position:fixed;right:16px;bottom:16px;z-index:80;
  display:inline-flex;align-items:center;gap:8px;
  padding:11px 14px;border:1px solid var(--line);border-radius:2px;
  background:rgba(11,18,24,.94);color:var(--snow);
  font-size:12px;letter-spacing:.14em;
  opacity:0;visibility:hidden;transform:translateY(8px);
  transition:opacity .24s var(--ease),transform .24s var(--ease),visibility .24s linear,border-color .2s var(--ease),color .2s var(--ease);
}
.to-top[data-visible="true"]{opacity:1;visibility:visible;transform:none;}
.to-top:hover{border-color:var(--cyan);color:var(--cyan);}
.to-top__arrow{font-family:var(--font-mono);color:var(--orange);}
.to-top__text{display:none;}

/* ---------- 13 渐入 ---------- */
[data-reveal]{opacity:0;transform:translateY(8px);transition:opacity .24s var(--ease),transform .24s var(--ease);}
[data-reveal].is-visible{opacity:1;transform:none;}

/* ---------- 14 平板 ---------- */
@media (min-width:768px){
  .footer__grid{grid-template-columns:repeat(2,minmax(0,1fr));}
  .footer__brand{grid-column:1 / -1;max-width:62ch;}
  .to-top__text{display:inline;}
}

/* ---------- 15 桌面：88px 侧边轨道 ---------- */
@media (min-width:1024px){
  body{padding-left:var(--rail-w);}
  .site-header{
    position:fixed;top:0;left:0;bottom:0;
    width:var(--rail-w);height:100vh;height:100dvh;
    display:flex;flex-direction:column;align-items:center;justify-content:flex-start;
    gap:0;padding:20px 0 16px;
    border-bottom:0;border-right:1px solid var(--line);
    background:linear-gradient(180deg,#0C1218 0%,#0A0E12 46%,#0B1116 100%);
    overflow-y:auto;overscroll-behavior:contain;scrollbar-width:none;
  }
  .site-header::-webkit-scrollbar{width:0;height:0;}
  .nav-toggle,.nav-scrim{display:none;}
  .brand{flex-direction:column;gap:12px;align-items:center;}
  .brand__text{display:block;}
  .brand__desc{display:none;}
  .brand__name{
    writing-mode:vertical-rl;text-orientation:mixed;
    font-size:13px;font-weight:500;letter-spacing:.2em;line-height:1;white-space:normal;
  }
  .nav{
    position:static;transform:none;visibility:visible;
    display:flex;flex-direction:column;align-items:center;
    width:100%;height:auto;flex:1 1 auto;
    padding:22px 0 0;background:none;border-left:0;overflow:visible;
  }
  .nav__kicker{display:none;}
  .nav__list{width:100%;border-top:1px solid var(--line);}
  .nav__item{width:100%;border-top:0;}
  .nav__link{
    flex-direction:column;align-items:center;gap:8px;
    width:100%;padding:12px 4px;
    font-size:12px;letter-spacing:.16em;
  }
  .nav__link:hover{padding-left:4px;}
  .nav__num{width:auto;font-size:10px;letter-spacing:.14em;}
  .nav__text{flex:0 0 auto;writing-mode:vertical-rl;text-orientation:mixed;letter-spacing:.14em;line-height:1.1;}
  .nav__tick{width:14px;height:1px;}
  .nav__link:hover .nav__tick{width:14px;}
  .nav__link[aria-current="page"] .nav__tick{width:26px;}
  .nav__actions{
    align-items:center;width:100%;
    margin-top:auto;padding:16px 0 4px;gap:14px;
    border-top:1px solid var(--line);
  }
  .nav__actions .btn--block{width:auto;justify-content:center;}
  .nav__actions .btn{
    writing-mode:vertical-rl;text-orientation:mixed;
    padding:14px 12px;font-size:12px;letter-spacing:.2em;
  }
  .nav__util{
    writing-mode:vertical-rl;text-orientation:mixed;
    padding:4px 0;font-size:10.5px;letter-spacing:.16em;
  }
  .scroll-progress{left:var(--rail-w);}
  .to-top{right:28px;bottom:28px;}
  [data-chapter]{scroll-margin-top:28px;}
  .footer__grid{grid-template-columns:1.5fr repeat(3,minmax(0,1fr));gap:clamp(24px,3vw,48px);}
  .footer__brand{grid-column:auto;}
  .footer__bar{padding-bottom:44px;}
}

/* ---------- 16 降低动效 ---------- */
@media (prefers-reduced-motion: reduce){
  html{scroll-behavior:auto;}
  *,*::before,*::after{transition-duration:.001ms !important;animation-duration:.001ms !important;animation-iteration-count:1 !important;}
  [data-reveal]{opacity:1;transform:none;}
  .nav{transition:none;}
  .scroll-progress__bar{transition:none;}
}