/* =========================================================
   FB赛场 · 共享外壳 /assets/site.css
   墨绿控制台 + 青柠状态线 + 等宽数字
   ========================================================= */

:root{
  --ink-950:#041712;
  --ink-900:#06231D;
  --ink-800:#0B3B2E;
  --ink-700:#123F35;
  --lime:#C8FF3D;
  --lime-soft:#E6FF9B;
  --silver:#C9D4D0;
  --mist:#EAF3EF;
  --amber:#F2B84B;
  --cyan:#7FD8C4;
  --text:#F4FBF8;

  --line:rgba(18,63,53,.95);
  --hairline:rgba(201,212,208,.16);
  --glass:rgba(11,59,46,.55);

  --font-display:"Barlow Condensed","Noto Sans SC","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:"IBM Plex Mono","SFMono-Regular",ui-monospace,"Roboto Mono","Courier New",monospace;

  --container:1320px;
  --radius:3px;
  --ease:cubic-bezier(.22,.61,.36,1);
  --dur:.2s;
}

/* ---------- reset ---------- */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;text-size-adjust:100%;scroll-behavior:smooth}
body{
  margin:0;
  background-color:var(--ink-900);
  background-image:
    radial-gradient(960px 560px at 92% -10%, rgba(200,255,61,.10), rgba(200,255,61,0) 68%),
    radial-gradient(760px 520px at -6% 18%, rgba(127,216,196,.08), rgba(127,216,196,0) 70%),
    linear-gradient(180deg,#06231D 0%,#041712 58%,#03110D 100%);
  background-repeat:no-repeat;
  color:var(--text);
  font-family:var(--font-body);
  font-size:16px;
  line-height:1.8;
  letter-spacing:.01em;
  -webkit-font-smoothing:antialiased;
}
img,svg,video{display:block;max-width:100%;height:auto}
ul,ol{margin:0 0 1.1em;padding-left:1.15em}
p{margin:0 0 1.1em}
figure,blockquote{margin:0}
button{font:inherit;color:inherit}
a{
  color:var(--cyan);
  text-decoration:underline;
  text-decoration-color:rgba(127,216,196,.42);
  text-underline-offset:3px;
  transition:color var(--dur) var(--ease),text-decoration-color var(--dur) var(--ease);
}
a:hover{color:var(--lime);text-decoration-color:rgba(200,255,61,.6)}
:focus-visible{outline:2px solid var(--lime);outline-offset:3px}
:focus:not(:focus-visible){outline:none}
#main-content{display:block;min-height:62vh;scroll-margin-top:96px}

/* ---------- 排版 ---------- */
h1,h2,h3,h4{
  margin:0 0 .6em;
  font-family:var(--font-display);
  font-weight:700;
  letter-spacing:.02em;
  line-height:1.18;
  text-wrap:balance;
}
.display-1{font-size:clamp(40px,6vw,84px);line-height:1.02;letter-spacing:.01em;text-transform:uppercase}
.display-2{font-size:clamp(26px,3.6vw,44px);line-height:1.1}
.h3{font-size:clamp(19px,1.6vw,24px);line-height:1.35}
.lead{font-size:clamp(16px,1.3vw,18.5px);line-height:1.85;color:var(--silver);max-width:64ch}
.text-muted{color:var(--silver)}
.mono{font-family:var(--font-mono);font-variant-numeric:tabular-nums;letter-spacing:.02em}
.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}

/* ---------- 容器与分区 ---------- */
.container{width:100%;max-width:var(--container);margin-inline:auto;padding-inline:clamp(16px,4vw,40px)}
.container--narrow{max-width:840px}
.section{position:relative;padding-block:clamp(48px,7vw,96px)}
.section--tight{padding-block:clamp(28px,4vw,48px)}
.section--deep{background:var(--ink-950);border-block:1px solid var(--line)}
.section--panel{background:linear-gradient(180deg,var(--ink-800),#082A22);border-block:1px solid var(--line)}
.eyebrow{
  display:inline-flex;align-items:center;gap:10px;
  margin:0 0 14px;
  font-family:var(--font-mono);font-size:11.5px;font-weight:500;
  letter-spacing:.18em;text-transform:uppercase;color:var(--lime);
}
.eyebrow::before{content:"";width:22px;height:1px;background:var(--lime)}

/* ---------- 按钮 ---------- */
.btn{
  --btn-bg:transparent;
  --btn-fg:var(--text);
  --btn-bd:rgba(201,212,208,.28);
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  min-height:40px;padding:10px 17px;
  font-family:var(--font-body);font-size:13.5px;font-weight:600;letter-spacing:.04em;
  color:var(--btn-fg);background:var(--btn-bg);
  border:1px solid var(--btn-bd);border-radius:2px;
  text-decoration:none;cursor:pointer;
  transition:background-color var(--dur) var(--ease),color var(--dur) var(--ease),
             border-color var(--dur) var(--ease),transform var(--dur) var(--ease),
             box-shadow var(--dur) var(--ease);
}
.btn:hover{transform:translateY(-2px)}
.btn--primary{--btn-bg:var(--lime);--btn-fg:#041712;--btn-bd:var(--lime);font-weight:700}
.btn--primary:hover{--btn-bg:var(--lime-soft);--btn-bd:var(--lime-soft);box-shadow:0 0 26px -8px rgba(200,255,61,.7)}
.btn--ghost{--btn-bg:rgba(201,212,208,.06);--btn-bd:rgba(201,212,208,.3)}
.btn--ghost:hover{--btn-fg:var(--lime);--btn-bd:var(--lime);--btn-bg:rgba(200,255,61,.1)}
.btn--quiet{--btn-bg:transparent;--btn-bd:transparent;--btn-fg:var(--cyan);padding-inline:4px;min-height:0;text-decoration:underline;text-underline-offset:4px}
.btn--quiet:hover{--btn-fg:var(--lime);transform:none}

/* ---------- 面包屑 ---------- */
.crumbs{
  display:flex;flex-wrap:wrap;align-items:center;gap:8px;
  margin:0 0 26px;padding:0;list-style:none;
  font-family:var(--font-mono);font-size:12px;letter-spacing:.06em;color:var(--silver);
}
.crumbs li{display:flex;align-items:center;gap:8px}
.crumbs li+li::before{content:"/";color:rgba(201,212,208,.42)}
.crumbs a{color:var(--silver);text-decoration:none}
.crumbs a:hover{color:var(--lime)}
.crumbs [aria-current="page"]{color:var(--lime)}

/* ---------- 网格 ---------- */
.grid{display:grid;gap:clamp(16px,2vw,28px)}
.grid--2{grid-template-columns:repeat(auto-fit,minmax(260px,1fr))}
.grid--3{grid-template-columns:repeat(auto-fit,minmax(220px,1fr))}
.grid--7-5{grid-template-columns:minmax(0,7fr) minmax(0,5fr)}
.grid--8-4{grid-template-columns:minmax(0,8fr) minmax(0,4fr)}
.grid--split{align-items:start}

/* ---------- 玻璃面板 ---------- */
.panel{
  padding:clamp(18px,2.2vw,30px);
  background:var(--glass);
  border:1px solid var(--hairline);
  border-radius:var(--radius);
  backdrop-filter:blur(10px) saturate(120%);
  -webkit-backdrop-filter:blur(10px) saturate(120%);
  transition:transform var(--dur) var(--ease),background-color var(--dur) var(--ease),border-color var(--dur) var(--ease);
}
.panel:hover{transform:translateY(-3px);background:rgba(18,63,53,.62);border-color:rgba(200,255,61,.34)}

/* ---------- 实色卡片 ---------- */
.card{
  position:relative;display:flex;flex-direction:column;gap:10px;
  padding:clamp(18px,2vw,26px);
  background:linear-gradient(180deg,var(--ink-800),#082A22);
  border:1px solid var(--line);border-radius:var(--radius);
  transition:transform var(--dur) var(--ease),border-color var(--dur) var(--ease),box-shadow var(--dur) var(--ease);
}
.card::before{
  content:"";position:absolute;inset:0 0 auto 0;height:2px;
  background:linear-gradient(90deg,var(--lime),rgba(200,255,61,0));
}
.card:hover{transform:translateY(-3px);border-color:rgba(200,255,61,.4);box-shadow:0 22px 44px -30px rgba(0,0,0,.95)}
.card__index{font-family:var(--font-mono);font-size:11.5px;letter-spacing:.16em;color:var(--lime);text-transform:uppercase}
.card__title{margin:0;font-family:var(--font-display);font-size:20px;font-weight:700;letter-spacing:.02em;line-height:1.3}
.card__body{margin:0;font-size:14.5px;line-height:1.75;color:var(--silver)}
.card__meta{margin:0;font-family:var(--font-mono);font-size:12px;letter-spacing:.08em;color:rgba(201,212,208,.75)}

/* ---------- 章节扉页 ---------- */
.chapter{
  display:grid;grid-template-columns:auto minmax(0,1fr);gap:clamp(14px,2vw,28px);
  align-items:start;position:relative;
  padding-top:clamp(20px,3vw,34px);
  border-top:1px solid var(--line);
}
.chapter__index{
  font-family:var(--font-mono);font-weight:600;line-height:1;
  font-size:clamp(30px,4vw,54px);color:var(--lime);letter-spacing:.02em;
}
.chapter__head{display:flex;flex-direction:column;gap:6px;min-width:0}
.chapter__title{margin:0;font-size:clamp(22px,2.6vw,32px)}
.chapter__note{
  margin:0;font-family:var(--font-mono);font-size:11.5px;
  letter-spacing:.18em;text-transform:uppercase;color:var(--silver);
}
.chapter__note--vertical{
  writing-mode:vertical-rl;
  position:absolute;left:-6px;top:clamp(20px,3vw,34px);
  letter-spacing:.3em;color:rgba(201,212,208,.7);
  display:none;
}
@media (min-width:1100px){.chapter__note--vertical{display:block}}

/* ---------- 标签 ---------- */
.tag{
  display:inline-flex;align-items:center;gap:6px;
  padding:4px 9px;border-radius:2px;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.1em;text-transform:uppercase;
  color:var(--silver);border:1px solid rgba(201,212,208,.28);background:rgba(201,212,208,.05);
}
.tag--lime{color:#041712;background:var(--lime);border-color:var(--lime);font-weight:600}
.tag--amber{color:#041712;background:var(--amber);border-color:var(--amber);font-weight:600}
.tag--cyan{color:var(--cyan);border-color:rgba(127,216,196,.45);background:rgba(127,216,196,.08)}

/* ---------- 数据锚点 ---------- */
.stat{display:flex;flex-direction:column;gap:4px}
.stat__value{
  font-family:var(--font-mono);font-variant-numeric:tabular-nums;font-weight:600;
  font-size:clamp(26px,3vw,40px);line-height:1;color:var(--lime);
}
.stat__label{font-family:var(--font-mono);font-size:12px;letter-spacing:.12em;text-transform:uppercase;color:var(--silver)}

/* ---------- 对照表 ---------- */
.table-wrap{
  overflow-x:auto;
  background:rgba(11,59,46,.45);
  border:1px solid var(--line);border-radius:var(--radius);
}
.table{width:100%;min-width:560px;border-collapse:collapse;font-size:14.5px}
.table th,.table td{padding:12px 16px;text-align:left;border-bottom:1px solid rgba(201,212,208,.12);vertical-align:top}
.table thead th{
  font-family:var(--font-mono);font-size:11.5px;font-weight:600;letter-spacing:.14em;text-transform:uppercase;
  color:var(--lime);background:rgba(4,23,18,.6);white-space:nowrap;
}
.table tbody tr:hover{background:rgba(200,255,61,.06)}
.table tbody tr:last-child td{border-bottom:0}

/* ---------- 图片容器基础规则 ---------- */
.media{
  position:relative;overflow:hidden;
  aspect-ratio:16/10;
  background:var(--ink-800);
  border:1px solid var(--line);border-radius:var(--radius);
}
.media img,.media video{width:100%;height:100%;object-fit:cover}
.media--slant{clip-path:polygon(0 0,100% 0,100% 92%,0 100%)}
.media--grid::after{
  content:"";position:absolute;inset:0;pointer-events:none;
  background-image:
    repeating-linear-gradient(90deg,rgba(200,255,61,.10) 0 1px,transparent 1px 48px),
    repeating-linear-gradient(0deg,rgba(200,255,61,.08) 0 1px,transparent 1px 48px);
  mix-blend-mode:screen;
}
.media--device{
  aspect-ratio:9/19;max-width:320px;border-radius:16px;
  box-shadow:0 30px 60px -34px rgba(0,0,0,.95),0 0 0 1px rgba(201,212,208,.22);
}
.media__caption{
  position:absolute;left:0;bottom:0;padding:7px 12px;
  background:rgba(4,23,18,.82);
  font-family:var(--font-mono);font-size:11px;letter-spacing:.1em;color:var(--silver);
}

/* ---------- 状态行 ---------- */
.status{display:flex;align-items:center;gap:10px;margin:0;font-size:13.5px;color:var(--silver)}
.status__dot{
  flex:none;width:8px;height:8px;border-radius:50%;
  background:var(--amber);box-shadow:0 0 0 4px rgba(242,184,75,.16);
}
.status__text{display:block}

/* ---------- 显现 / 计数（页面阶段可选） ---------- */
[data-reveal]{opacity:0;transform:translateY(14px);transition:opacity .34s var(--ease),transform .34s var(--ease)}
[data-reveal][data-revealed]{opacity:1;transform:none}

/* =========================================================
   跳转链接
   ========================================================= */
.skip-link{
  position:fixed;top:10px;left:10px;z-index:300;
  transform:translateY(-180%);
  padding:10px 18px;border-radius:2px;
  background:var(--lime);color:#041712;
  font-size:14px;font-weight:700;text-decoration:none;
  transition:transform var(--dur) var(--ease);
}
.skip-link:focus-visible,.skip-link:focus{transform:none;color:#041712}

/* =========================================================
   页头：框架式导航轨
   ========================================================= */
.site-header{
  position:sticky;top:0;z-index:100;
  color:var(--text);
  background:linear-gradient(180deg,rgba(4,23,18,.97),rgba(6,35,29,.92));
  border-bottom:1px solid var(--line);
  box-shadow:0 1px 0 rgba(200,255,61,.16),0 20px 44px -34px rgba(0,0,0,.95);
  backdrop-filter:blur(14px) saturate(120%);
  -webkit-backdrop-filter:blur(14px) saturate(120%);
  transition:background-color var(--dur) var(--ease),box-shadow var(--dur) var(--ease);
}
.site-header[data-scrolled]{background:rgba(4,23,18,.99);box-shadow:0 1px 0 rgba(200,255,61,.3),0 24px 50px -34px #000}
.header-inner{
  display:flex;align-items:stretch;
  gap:clamp(10px,2vw,26px);
  width:100%;max-width:var(--container);margin-inline:auto;
  padding-inline:clamp(14px,2.6vw,32px);
  min-height:72px;
}

/* 品牌 */
.header-brand{display:flex;align-items:center;gap:14px;padding-block:10px;flex:0 0 auto;min-width:0}
.brand-link{display:flex;align-items:center;gap:12px;text-decoration:none;color:inherit}
.brand-link:hover{color:inherit}
.brand-mark{
  display:grid;place-items:center;flex:none;
  width:38px;height:38px;border-radius:2px;
  background:var(--lime);color:#041712;
  font-family:var(--font-mono);font-size:14px;font-weight:600;letter-spacing:.02em;
  box-shadow:0 0 0 1px rgba(200,255,61,.35),0 0 24px -8px rgba(200,255,61,.65);
}
.brand-text{display:flex;flex-direction:column;line-height:1.2;min-width:0}
.brand-title{font-family:var(--font-display);font-size:20px;font-weight:700;letter-spacing:.12em;text-transform:uppercase}
.brand-sub{display:none;font-size:11.5px;letter-spacing:.06em;color:var(--silver);white-space:nowrap}
.brand-domain{
  display:none;margin:0;padding-left:16px;align-self:center;
  border-left:1px solid var(--line);
  font-size:12px;letter-spacing:.08em;color:rgba(201,212,208,.68);white-space:nowrap;
}
@media (min-width:1360px){.brand-sub{display:block}}
@media (min-width:1500px){.brand-domain{display:block}}

/* 移动导航按钮 */
.nav-toggle{
  display:none;align-items:center;gap:10px;align-self:center;
  margin-left:auto;padding:9px 14px;border-radius:2px;
  background:rgba(200,255,61,.08);color:var(--text);
  border:1px solid rgba(200,255,61,.42);
  font-family:var(--font-mono);font-size:11.5px;letter-spacing:.16em;text-transform:uppercase;
  cursor:pointer;
}
.nav-toggle-glyph{display:inline-flex;flex-direction:column;justify-content:center;gap:4px;width:16px}
.nav-toggle-glyph span{display:block;height:2px;background:var(--lime);transition:transform var(--dur) var(--ease),opacity var(--dur) var(--ease)}
.nav-toggle-text{white-space:nowrap}
.site-header[data-open] .nav-toggle-glyph span:nth-child(1){transform:translateY(6px) rotate(45deg)}
.site-header[data-open] .nav-toggle-glyph span:nth-child(2){opacity:0}
.site-header[data-open] .nav-toggle-glyph span:nth-child(3){transform:translateY(-6px) rotate(-45deg)}

/* 导航轨 */
.site-nav{
  display:flex;align-items:stretch;justify-content:flex-end;flex:1 1 auto;
  gap:clamp(8px,1.4vw,18px);min-width:0;
}
.nav-list{display:flex;align-items:stretch;flex-wrap:nowrap;margin:0;padding:0;list-style:none}
.nav-item{display:flex}
.nav-link{
  position:relative;display:flex;align-items:center;gap:8px;
  padding-inline:clamp(9px,.95vw,14px);padding-block:10px;
  color:var(--silver);text-decoration:none;
  font-size:13.5px;font-weight:500;letter-spacing:.03em;
  border-left:1px solid var(--line);
  transition:color var(--dur) var(--ease),background-color var(--dur) var(--ease);
}
.nav-item:last-child .nav-link{border-right:1px solid var(--line)}
.nav-link__index{font-family:var(--font-mono);font-size:10.5px;letter-spacing:.04em;color:var(--lime);opacity:.72}
.nav-link__label{white-space:nowrap}
.nav-link:hover,.nav-link:focus-visible{color:var(--text);background:rgba(200,255,61,.09)}
.nav-link:hover .nav-link__index,.nav-link:focus-visible .nav-link__index{opacity:1}
.nav-link[aria-current="page"]{color:var(--text);background:rgba(200,255,61,.12)}
.nav-link[aria-current="page"] .nav-link__index{opacity:1}
.nav-link[aria-current="page"]::after{
  content:"";position:absolute;left:0;right:0;bottom:0;height:2px;
  background:var(--lime);box-shadow:0 0 12px rgba(200,255,61,.6);
}
.nav-actions{
  display:flex;align-items:center;gap:8px;flex:none;
  padding-left:clamp(6px,1vw,14px);
  border-left:1px solid var(--line);
}

/* 页头进度线 */
.header-progress{position:relative;height:2px;overflow:hidden;background:rgba(18,63,53,.9)}
.header-progress__bar{
  display:block;height:100%;width:0;
  background:linear-gradient(90deg,var(--cyan),var(--lime));
  box-shadow:0 0 12px rgba(200,255,61,.7);
}

/* =========================================================
   页脚：关机前的状态面板
   ========================================================= */
.site-footer{
  position:relative;
  margin-top:clamp(48px,7vw,96px);
  background:linear-gradient(180deg,var(--ink-950),#03110D 72%);
  border-top:1px solid var(--line);
  color:var(--silver);
}
.site-footer::before{
  content:"";position:absolute;inset:0 0 auto 0;height:2px;
  background:linear-gradient(90deg,var(--lime),var(--cyan) 42%,rgba(200,255,61,0) 94%);
  opacity:.75;
}
.footer-inner{
  width:100%;max-width:var(--container);margin-inline:auto;
  padding:clamp(34px,5vw,64px) clamp(16px,4vw,40px) clamp(20px,3vw,30px);
}
.footer-top{
  display:flex;flex-wrap:wrap;align-items:flex-end;justify-content:space-between;
  gap:18px 32px;
  padding-bottom:clamp(20px,3vw,32px);
  border-bottom:1px solid var(--line);
}
.footer-brand{display:flex;flex-direction:column;gap:10px;max-width:48ch;min-width:0}
.footer-brand__name{
  display:inline-flex;align-items:center;gap:10px;
  font-family:var(--font-display);font-size:25px;font-weight:700;letter-spacing:.12em;
  text-transform:uppercase;color:var(--text);text-decoration:none;
}
.footer-brand__name:hover{color:var(--lime)}
.footer-brand__mark{
  display:grid;place-items:center;flex:none;
  width:30px;height:30px;border-radius:2px;
  background:var(--lime);color:#041712;
  font-family:var(--font-mono);font-size:11.5px;font-weight:600;letter-spacing:0;
}
.footer-brand__text{margin:0;font-size:14.5px;line-height:1.78;color:var(--silver);max-width:44ch}
.footer-domain{margin:0;font-size:12px;letter-spacing:.09em;color:rgba(201,212,208,.62)}
.footer-status{max-width:34ch;font-size:13px;line-height:1.7}
.footer-grid{
  display:grid;
  grid-template-columns:minmax(0,1.5fr) minmax(0,1fr) minmax(0,1fr);
  gap:clamp(20px,3vw,40px);
  padding-block:clamp(24px,3.4vw,40px);
  border-bottom:1px solid var(--line);
}
.footer-col{display:flex;flex-direction:column;gap:12px;min-width:0}
.footer-col__title{
  margin:0;
  font-family:var(--font-mono);font-size:11px;font-weight:600;
  letter-spacing:.2em;text-transform:uppercase;color:var(--lime);
}
.footer-contact{display:flex;flex-direction:column;gap:8px}
.footer-contact__row{display:flex;flex-wrap:wrap;align-items:baseline;gap:10px;margin:0;font-size:14px;line-height:1.7}
.footer-contact__key{
  flex:none;min-width:34px;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.14em;text-transform:uppercase;
  color:rgba(201,212,208,.6);
}
.footer-contact__val{color:var(--text);word-break:break-word}
.footer-list{display:flex;flex-direction:column;gap:8px;margin:0;padding:0;list-style:none;font-size:14px}
.footer-list a{color:var(--silver);text-decoration:none;transition:color var(--dur) var(--ease)}
.footer-list a:hover{color:var(--lime);text-decoration:underline;text-decoration-color:rgba(200,255,61,.6)}
.footer-bottom{
  display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;
  gap:10px 24px;
  padding-top:clamp(16px,2.4vw,26px);
  font-family:var(--font-mono);font-size:12px;letter-spacing:.06em;
  color:rgba(201,212,208,.66);
}
.footer-legal,.footer-icp,.footer-note{margin:0}
.footer-icp{color:var(--silver)}
.footer-note{color:rgba(201,212,208,.5)}

/* =========================================================
   响应式
   ========================================================= */
@media (max-width:1179px){
  .nav-toggle{display:inline-flex}
  .site-nav{
    position:absolute;left:0;right:0;top:100%;
    display:none;flex-direction:column;align-items:stretch;gap:0;
    max-height:calc(100vh - 74px);overflow-y:auto;
    padding:10px clamp(14px,2.6vw,32px) 20px;
    background:rgba(4,23,18,.99);
    border-top:1px solid var(--line);
    border-bottom:1px solid var(--line);
    box-shadow:0 30px 60px -32px #000;
  }
  .site-header[data-open] .site-nav{display:flex}
  .nav-list{flex-direction:column;width:100%}
  .nav-link{
    justify-content:flex-start;gap:12px;
    padding:14px 6px;font-size:16px;
    border-left:0;border-top:1px solid var(--line);
  }
  .nav-item:first-child .nav-link{border-top:0}
  .nav-item:last-child .nav-link{border-right:0}
  .nav-link[aria-current="page"]{background:rgba(200,255,61,.14)}
  .nav-link[aria-current="page"]::after{left:0;right:auto;top:10px;bottom:10px;width:2px;height:auto}
  .nav-actions{
    flex-direction:column;align-items:stretch;gap:10px;
    padding:18px 0 0;border-left:0;border-top:1px solid var(--line);
  }
  .nav-actions .btn{width:100%}
  .header-brand{padding-block:8px}
}

@media (max-width:900px){
  .grid--7-5,.grid--8-4{grid-template-columns:minmax(0,1fr)}
  .footer-grid{grid-template-columns:minmax(0,1fr) minmax(0,1fr)}
  .footer-col:first-child{grid-column:1 / -1}
}

@media (max-width:640px){
  body{font-size:15.5px}
  .header-inner{min-height:64px}
  .brand-title{font-size:17px;letter-spacing:.1em}
  .brand-mark{width:34px;height:34px;font-size:12.5px}
  .display-1{font-size:clamp(34px,9vw,52px)}
  .footer-grid{grid-template-columns:minmax(0,1fr)}
  .footer-top{align-items:flex-start}
  .footer-status{max-width:none}
  .footer-brand__name{font-size:22px}
  .chapter{grid-template-columns:minmax(0,1fr);gap:10px}
  .chapter__index{font-size:34px}
}

@media (prefers-reduced-motion: reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
  }
  .btn:hover,.card:hover,.panel:hover{transform:none}
  [data-reveal]{opacity:1;transform:none}
  .header-progress__bar{transition:none}
}