/* =========================================================
   三公平台 · 共享样式表 /assets/site.css
   墨蓝 + 铜金 · 展览画册式目录体系
   ========================================================= */

/* ---------- 1. 设计变量 ---------- */
:root{
  --ink-900:#0B1B2B;
  --ink-700:#14304C;
  --ink-500:#2C5A80;
  --copper-500:#B4884B;
  --copper-200:#E0C79A;
  --paper-50:#F7F5F1;
  --paper-100:#ECE8E1;
  --stone-500:#5C6470;
  --cinnabar-600:#C0402A;
  --teal-700:#10504A;

  --line:rgba(11,27,43,.14);
  --line-strong:rgba(11,27,43,.28);
  --line-copper:rgba(180,136,75,.55);
  --line-invert:rgba(247,245,241,.14);

  --font-display:"Oswald","Source Han Sans SC Narrow","PingFang SC","Microsoft YaHei",sans-serif;
  --font-body:"Source Han Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  --font-mono:"IBM Plex Mono","JetBrains Mono","Sarasa Mono SC",ui-monospace,monospace;

  --h1:clamp(2.4rem,5vw,4.2rem);
  --h2:clamp(1.6rem,2.6vw,2.4rem);
  --h3:1.15rem;
  --index:0.78rem;
  --lh:1.75;

  --shell:1240px;
  --gutter:24px;
  --toc:200px;
  --header-h:96px;
  --ease:cubic-bezier(0.22,0.61,0.36,1);
  --shadow-1:0 1px 2px rgba(11,27,43,.08);
}

/* ---------- 2. Reset ---------- */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body,h1,h2,h3,h4,p,dl,dd,figure,blockquote{margin:0}
ul,ol{margin:0;padding:0;list-style:none}
img,svg{display:block;max-width:100%}
button,input,select,textarea{font:inherit;color:inherit}
a{color:inherit;text-decoration:none}
table{border-collapse:collapse}
:focus-visible{outline:2px solid var(--copper-500);outline-offset:2px}

/* ---------- 3. 中文排版基线 ---------- */
body{
  background:var(--paper-50);
  color:var(--ink-700);
  font-family:var(--font-body);
  font-size:16.5px;
  line-height:var(--lh);
  font-weight:400;
  letter-spacing:.005em;
  -webkit-font-smoothing:antialiased;
}
p{line-height:var(--lh)}
strong{font-weight:500;color:var(--ink-900)}

.h1,.h2{font-family:var(--font-display);font-weight:300;letter-spacing:-.01em;color:var(--ink-900)}
.h1{font-size:var(--h1);line-height:1.05}
.h2{font-size:var(--h2);line-height:1.1}
.h3{font-family:var(--font-display);font-weight:500;font-size:var(--h3);line-height:1.35;color:var(--ink-700)}
.eyebrow{font-family:var(--font-mono);font-size:var(--index);letter-spacing:.14em;color:var(--stone-500);text-transform:uppercase}
.lede{font-size:1.05rem;line-height:1.8;color:var(--ink-700);max-width:62ch}
.prose{font-size:16.5px;line-height:var(--lh);color:var(--ink-700);max-width:70ch}
.prose p+p{margin-top:1.2em}
.prose ul{margin:1em 0;padding-left:0}
.prose li{position:relative;padding-left:16px;margin-top:.5em}
.prose li::before{content:"";position:absolute;left:0;top:.72em;width:8px;height:1px;background:var(--copper-500)}
.prose a{color:var(--ink-500);border-bottom:1px solid var(--line-copper)}
.prose a:hover{color:var(--copper-500)}
.prose h2{margin-top:1.6em}
.prose h3{margin-top:1.4em}

/* ---------- 4. 容器与栅格 ---------- */
.container{width:min(100% - 40px,var(--shell));margin-inline:auto}
.container--narrow{width:min(100% - 40px,760px);margin-inline:auto}

.layout{display:grid;grid-template-columns:minmax(0,1fr);gap:32px;align-items:start}
.layout__toc{display:none}
.layout__main{min-width:0}
@media (min-width:1200px){
  .layout{grid-template-columns:var(--toc) minmax(0,1fr);gap:48px}
  .layout__toc{display:block;position:sticky;top:calc(var(--header-h) + 24px)}
}

.grid-12{display:grid;grid-template-columns:repeat(12,minmax(0,1fr));gap:var(--gutter)}
.span-3{grid-column:span 3}
.span-4{grid-column:span 4}
.span-6{grid-column:span 6}
.span-8{grid-column:span 8}
.span-12{grid-column:span 12}
@media (max-width:980px){
  .grid-12{grid-template-columns:repeat(6,minmax(0,1fr))}
  .span-8,.span-6{grid-column:span 6}
  .span-4{grid-column:span 3}
  .span-3{grid-column:span 2}
}
@media (max-width:640px){
  .grid-12{grid-template-columns:1fr}
  .span-3,.span-4,.span-6,.span-8,.span-12{grid-column:1/-1}
}

/* ---------- 5. 页面头部：批次条 + 命令栏 ---------- */
.site-header{
  position:sticky;
  top:0;
  z-index:60;
  background:var(--paper-50);
  border-bottom:1px solid var(--line-strong);
}

.skip-link{
  position:absolute;
  left:12px;
  top:-64px;
  z-index:90;
  padding:10px 16px;
  background:var(--ink-900);
  color:var(--paper-50);
  border:1px solid var(--copper-500);
  font-size:.82rem;
  transition:top .18s var(--ease);
}
.skip-link:focus{top:8px}

.batch-bar{background:var(--ink-900);color:var(--copper-200)}
.batch-bar__inner{
  width:min(100% - 32px,var(--shell));
  margin-inline:auto;
  height:34px;
  display:flex;
  align-items:center;
  gap:14px;
  font-family:var(--font-mono);
  font-size:.72rem;
  letter-spacing:.04em;
}
.batch-bar__pulse{
  flex:0 0 auto;
  width:6px;
  height:6px;
  border-radius:50%;
  background:var(--cinnabar-600);
  box-shadow:0 0 0 3px rgba(192,64,42,.18);
  animation:sgb-pulse 2.6s var(--ease) infinite;
}
@keyframes sgb-pulse{0%,100%{opacity:1}50%{opacity:.35}}
.batch-bar__text{
  white-space:nowrap;
  overflow:hidden;
  text-overflow:ellipsis;
  color:var(--copper-200);
}
.batch-bar__meta{
  margin-left:auto;
  white-space:nowrap;
  color:rgba(224,199,154,.62);
}
@media (max-width:720px){.batch-bar__meta{display:none}}

.command-bar{
  width:min(100% - 32px,var(--shell));
  margin-inline:auto;
  height:60px;
  display:flex;
  align-items:center;
  gap:20px;
}

.brand{display:flex;align-items:center;gap:10px;flex:0 0 auto}
.brand__mark{
  width:28px;
  height:28px;
  flex:0 0 auto;
  display:grid;
  place-items:center;
  background:var(--ink-900);
  border:1px solid var(--copper-500);
  color:var(--copper-200);
  font-family:var(--font-mono);
  font-size:.62rem;
  letter-spacing:.06em;
}
.brand__text{display:flex;flex-direction:column;gap:1px}
.brand__name{
  display:block;
  font-family:var(--font-display);
  font-weight:500;
  font-size:1.05rem;
  line-height:1.1;
  letter-spacing:.02em;
  color:var(--ink-900);
}
.brand__note{
  display:block;
  font-family:var(--font-mono);
  font-size:.6rem;
  letter-spacing:.14em;
  color:var(--stone-500);
}

.nav{margin-left:auto}
.nav__list{display:flex;align-items:center;gap:2px}
.nav__item{list-style:none}
.nav__link{
  position:relative;
  display:flex;
  align-items:baseline;
  gap:6px;
  padding:8px 12px;
  font-size:.86rem;
  color:var(--ink-700);
  transition:color .18s var(--ease),background .18s var(--ease);
}
.nav__link::after{
  content:"";
  position:absolute;
  left:12px;
  right:12px;
  bottom:-1px;
  height:2px;
  background:var(--copper-500);
  transform:scaleX(0);
  transform-origin:left;
  transition:transform .18s var(--ease);
}
.nav__link:hover{color:var(--ink-500);background:rgba(20,48,76,.04)}
.nav__link:hover::after{transform:scaleX(1)}
.nav__link[aria-current="page"]{color:var(--ink-900);font-weight:500}
.nav__link[aria-current="page"]::after{transform:scaleX(1)}
.nav__num{
  font-family:var(--font-mono);
  font-size:.6rem;
  letter-spacing:.06em;
  color:var(--copper-500);
}
.nav__link[aria-current="page"] .nav__num{color:var(--cinnabar-600)}

.command-bar__actions{display:flex;align-items:center;gap:10px;flex:0 0 auto}
.command-hint{
  font-family:var(--font-mono);
  font-size:.68rem;
  letter-spacing:.04em;
  color:var(--stone-500);
  padding-right:12px;
  border-right:1px solid var(--line);
}
@media (max-width:1200px){.command-hint{display:none}}

.nav-toggle{
  display:none;
  align-items:center;
  gap:8px;
  padding:8px 12px;
  background:var(--paper-50);
  border:1px solid var(--line-strong);
  border-radius:2px;
  color:var(--ink-900);
  font-family:var(--font-mono);
  font-size:.72rem;
  letter-spacing:.06em;
  cursor:pointer;
}
.nav-toggle:hover{border-color:var(--copper-500)}
.nav-toggle__bars{
  position:relative;
  display:block;
  width:16px;
  height:1px;
  background:currentColor;
}
.nav-toggle__bars::before,
.nav-toggle__bars::after{
  content:"";
  position:absolute;
  left:0;
  width:16px;
  height:1px;
  background:currentColor;
  transition:transform .2s var(--ease),opacity .2s var(--ease);
}
.nav-toggle__bars::before{top:-5px}
.nav-toggle__bars::after{top:5px}
.site-header[data-open="true"] .nav-toggle__bars{background:transparent}
.site-header[data-open="true"] .nav-toggle__bars::before{transform:translateY(5px) rotate(45deg)}
.site-header[data-open="true"] .nav-toggle__bars::after{transform:translateY(-5px) rotate(-45deg)}

.scroll-progress{
  position:absolute;
  left:0;
  bottom:-1px;
  width:100%;
  height:2px;
  background:var(--copper-500);
  transform:scaleX(0);
  transform-origin:left;
  pointer-events:none;
  transition:transform .12s linear;
}

@media (max-width:980px){
  .nav-toggle{display:inline-flex}
  .nav{
    position:absolute;
    top:100%;
    left:0;
    right:0;
    margin-left:0;
    display:none;
    padding:6px 0 10px;
    background:var(--paper-50);
    border-bottom:1px solid var(--line-strong);
    box-shadow:var(--shadow-1);
  }
  .site-header[data-open="true"] .nav{display:block}
  .nav__list{flex-direction:column;align-items:stretch;gap:0}
  .nav__link{padding:12px 20px;border-bottom:1px solid var(--line);justify-content:flex-start}
  .nav__link::after{display:none}
  .nav__link[aria-current="page"]{
    background:rgba(180,136,75,.12);
    box-shadow:inset 3px 0 0 var(--copper-500);
  }
}
@media (max-width:560px){
  .header-cta{display:none}
  .command-bar{gap:12px}
}

/* ---------- 6. 页面底部 ---------- */
.site-footer{
  position:relative;
  margin-top:96px;
  background:var(--ink-900);
  color:var(--paper-50);
}
.footer-frame{
  position:relative;
  width:min(100% - 40px,var(--shell));
  margin-inline:auto;
  padding:56px 0 28px;
}
.footer-frame::before{
  content:"";
  position:absolute;
  top:0;
  left:0;
  right:0;
  height:1px;
  background:linear-gradient(90deg,var(--copper-500),rgba(180,136,75,0) 62%);
}

.footer-top{
  display:flex;
  flex-wrap:wrap;
  align-items:flex-end;
  justify-content:space-between;
  gap:28px;
  padding-bottom:28px;
  border-bottom:1px solid var(--line-invert);
}
.footer-brand__name{
  font-family:var(--font-display);
  font-weight:300;
  font-size:clamp(1.8rem,3.4vw,2.6rem);
  line-height:1.05;
  letter-spacing:-.01em;
  color:var(--paper-50);
}
.footer-brand__line{
  margin-top:8px;
  font-family:var(--font-mono);
  font-size:.72rem;
  letter-spacing:.04em;
  color:var(--copper-200);
}

.footer-stats{display:flex;flex-wrap:wrap;gap:28px}
.stat{display:flex;flex-direction:column;gap:2px}
.stat__num{
  font-family:var(--font-mono);
  font-weight:600;
  font-size:1.2rem;
  letter-spacing:.04em;
  color:var(--copper-200);
}
.stat__label{
  font-size:.72rem;
  letter-spacing:.06em;
  color:rgba(247,245,241,.6);
}

.footer-grid{
  display:grid;
  grid-template-columns:repeat(3,minmax(0,1fr)) minmax(240px,1.3fr);
  gap:32px;
  padding:36px 0;
  border-bottom:1px solid var(--line-invert);
}
.footer-col{min-width:0}
.footer-col__title{
  display:block;
  margin-bottom:14px;
  padding-bottom:10px;
  border-bottom:1px solid rgba(180,136,75,.35);
  font-family:var(--font-mono);
  font-weight:400;
  font-size:.72rem;
  letter-spacing:.12em;
  color:var(--copper-200);
}
.footer-col__num{margin-right:8px;color:var(--copper-500)}
.footer-links{display:flex;flex-direction:column;gap:10px}
.footer-link{
  position:relative;
  display:inline-block;
  padding-left:14px;
  font-size:.88rem;
  color:rgba(247,245,241,.78);
  transition:color .18s var(--ease);
}
.footer-link::before{
  content:"";
  position:absolute;
  left:0;
  top:.72em;
  width:8px;
  height:1px;
  background:var(--copper-500);
  transition:width .18s var(--ease);
}
.footer-link:hover{color:var(--paper-50)}
.footer-link:hover::before{width:12px}

.footer-contact{min-width:0}
.footer-contact__row{
  display:flex;
  gap:12px;
  padding:9px 0;
  border-bottom:1px dashed var(--line-invert);
  font-size:.84rem;
}
.footer-contact__key{
  flex:0 0 44px;
  font-family:var(--font-mono);
  font-size:.68rem;
  letter-spacing:.06em;
  color:var(--copper-500);
}
.footer-contact__val{color:rgba(247,245,241,.82);word-break:break-word}
.footer-contact__note{
  margin-top:12px;
  font-size:.76rem;
  line-height:1.7;
  color:rgba(247,245,241,.55);
}

.footer-legal{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  justify-content:space-between;
  gap:12px 24px;
  padding-top:22px;
  font-family:var(--font-mono);
  font-size:.7rem;
  letter-spacing:.03em;
  color:rgba(247,245,241,.5);
}
.footer-legal__icp{color:rgba(247,245,241,.7)}
.footer-legal__note{color:rgba(224,199,154,.7)}

@media (max-width:1024px){
  .footer-grid{grid-template-columns:repeat(2,minmax(0,1fr))}
}
@media (max-width:640px){
  .site-footer{margin-top:64px}
  .footer-top{flex-direction:column;align-items:flex-start}
  .footer-grid{grid-template-columns:1fr;gap:28px}
  .footer-stats{gap:20px}
}

/* ---------- 7. 按钮与状态标签 ---------- */
.btn{
  display:inline-flex;
  align-items:center;
  gap:8px;
  padding:10px 18px;
  border:1px solid var(--ink-700);
  border-radius:2px;
  background:transparent;
  color:var(--ink-700);
  font-size:.85rem;
  letter-spacing:.02em;
  cursor:pointer;
  transition:background .18s var(--ease),color .18s var(--ease),border-color .18s var(--ease);
}
.btn:hover{background:var(--ink-700);color:var(--paper-50)}
.btn--copper{
  border-color:var(--copper-500);
  background:rgba(224,199,154,.16);
  color:var(--ink-900);
}
.btn--copper:hover{background:var(--copper-500);color:var(--ink-900)}
.btn--solid{background:var(--ink-700);color:var(--paper-50)}
.btn--solid:hover{background:var(--ink-500);border-color:var(--ink-500)}
.btn--sm{padding:7px 14px;font-size:.78rem}
.btn--block{width:100%;justify-content:center}

.tag{
  display:inline-flex;
  align-items:center;
  gap:6px;
  padding:3px 8px;
  border:1px solid var(--line-strong);
  border-radius:2px;
  background:var(--paper-100);
  color:var(--ink-700);
  font-family:var(--font-mono);
  font-size:.68rem;
  letter-spacing:.06em;
}
.tag--copper{border-color:var(--line-copper);background:rgba(224,199,154,.28);color:var(--ink-900)}
.tag--version{border-color:var(--line-copper);background:var(--copper-200);color:var(--ink-900)}
.tag--status{border-color:rgba(192,64,42,.55);background:rgba(192,64,42,.08);color:var(--cinnabar-600)}
.tag--status::before{
  content:"";
  width:5px;
  height:5px;
  border-radius:50%;
  background:var(--cinnabar-600);
}

/* ---------- 8. 区块、分区底色与分隔线 ---------- */
.section{position:relative;padding:72px 0}
.section--tight{padding:44px 0}
.section--dense{padding:32px 0}
.section__head{
  display:flex;
  flex-wrap:wrap;
  align-items:baseline;
  gap:16px;
  margin-bottom:28px;
  padding-bottom:14px;
  border-bottom:1px solid var(--line);
}
.section__num{
  font-family:var(--font-mono);
  font-size:.72rem;
  letter-spacing:.08em;
  color:var(--copper-500);
}
.bg-paper{background:var(--paper-50)}
.bg-panel{background:var(--paper-100)}
.bg-ink{background:var(--ink-900);color:var(--paper-50)}
.bg-teal{background:var(--teal-700);color:var(--paper-50)}
.bg-ink .h1,.bg-ink .h2,.bg-teal .h1,.bg-teal .h2{color:var(--paper-50)}
.rule{height:1px;border:0;margin:0;background:var(--line)}
.rule--copper{background:linear-gradient(90deg,var(--copper-500),rgba(180,136,75,0) 70%)}

/* ---------- 9. 目录锚点 ---------- */
.toc{border-left:1px solid var(--line);padding-left:16px}
.toc__title{
  margin-bottom:14px;
  font-family:var(--font-mono);
  font-size:.68rem;
  letter-spacing:.12em;
  color:var(--stone-500);
}
.toc__list{display:flex;flex-direction:column;gap:2px}
.toc__link{
  display:block;
  width:100%;
  padding:7px 8px 7px 10px;
  border:0;
  border-left:2px solid transparent;
  background:transparent;
  text-align:left;
  font-family:var(--font-body);
  font-size:.84rem;
  color:var(--stone-500);
  cursor:pointer;
  transition:color .18s var(--ease),border-color .18s var(--ease),background .18s var(--ease);
}
.toc__link:hover{color:var(--ink-700);background:var(--paper-100)}
.toc__link[aria-current="true"]{
  color:var(--ink-900);
  border-left-color:var(--copper-500);
  background:var(--paper-100);
}
.toc__num{
  margin-right:8px;
  font-family:var(--font-mono);
  font-size:.66rem;
  letter-spacing:.06em;
  color:var(--copper-500);
}

/* ---------- 10. 面包屑 ---------- */
.breadcrumb{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:8px;
  padding:14px 0;
  font-family:var(--font-mono);
  font-size:.7rem;
  letter-spacing:.05em;
  color:var(--stone-500);
}
.breadcrumb a{color:var(--ink-500)}
.breadcrumb a:hover{color:var(--copper-500)}
.breadcrumb__sep{color:var(--copper-500)}
.breadcrumb__current{color:var(--ink-900)}

/* ---------- 11. 卡片 ---------- */
.card{
  position:relative;
  padding:22px 24px;
  border:1px solid var(--line);
  border-radius:2px;
  background:var(--paper-50);
  box-shadow:var(--shadow-1);
  transition:border-color .18s var(--ease);
}
.card:hover{border-color:var(--line-copper)}
.card--dense{padding:14px 16px}
.card--panel{background:var(--paper-100)}
.card--teal{
  background:var(--teal-700);
  border-color:rgba(224,199,154,.4);
  color:var(--paper-50);
}
.card__head{
  display:flex;
  flex-wrap:wrap;
  align-items:baseline;
  justify-content:space-between;
  gap:12px;
  margin-bottom:10px;
}
.card__title{
  font-family:var(--font-display);
  font-weight:500;
  font-size:1.02rem;
  letter-spacing:.01em;
  color:var(--ink-900);
}
.card__meta{
  font-family:var(--font-mono);
  font-size:.68rem;
  letter-spacing:.04em;
  color:var(--stone-500);
}
.card__text{font-size:.92rem;line-height:1.7;color:var(--ink-700)}
.card__foot{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  justify-content:space-between;
  gap:12px;
  margin-top:14px;
  padding-top:12px;
  border-top:1px solid var(--line);
}
.card--teal .card__title{color:var(--paper-50)}
.card--teal .card__meta{color:var(--copper-200)}
.card--teal .card__text{color:rgba(247,245,241,.82)}
.card--teal .card__foot{border-top-color:var(--line-invert)}

/* ---------- 12. 索引清单 ---------- */
.index-list{border-top:1px solid var(--line)}
.index-list__item{
  display:flex;
  align-items:flex-start;
  gap:16px;
  padding:12px 4px;
  border-bottom:1px solid var(--line);
  transition:background .18s var(--ease);
}
.index-list__item:hover{background:var(--paper-100)}
.index-list__num{
  flex:0 0 40px;
  padding-top:.2em;
  font-family:var(--font-mono);
  font-size:.72rem;
  letter-spacing:.04em;
  color:var(--copper-500);
}
.index-list__body{flex:1;min-width:0}
.index-list__title{font-size:.95rem;font-weight:500;color:var(--ink-900)}
.index-list__desc{margin-top:2px;font-size:.82rem;line-height:1.65;color:var(--stone-500)}

/* ---------- 13. 可勾选清单 ---------- */
.checklist{display:grid;gap:8px}
.checklist__row{
  display:flex;
  align-items:flex-start;
  gap:10px;
  padding:10px 12px;
  border:1px solid var(--line);
  border-radius:2px;
  background:var(--paper-50);
  cursor:pointer;
  transition:border-color .18s var(--ease),background .18s var(--ease);
}
.checklist__row:hover{border-color:var(--line-copper)}
.checklist__row[data-checked="true"]{background:var(--paper-100);border-color:var(--line-copper)}
.checklist__box{
  position:relative;
  flex:0 0 auto;
  width:16px;
  height:16px;
  margin-top:3px;
  border:1px solid var(--line-strong);
  border-radius:1px;
  background:var(--paper-50);
}
.checklist__row[data-checked="true"] .checklist__box{background:var(--ink-700);border-color:var(--ink-700)}
.checklist__row[data-checked="true"] .checklist__box::after{
  content:"";
  position:absolute;
  left:4px;
  top:1px;
  width:5px;
  height:9px;
  border:1px solid var(--copper-200);
  border-top:0;
  border-left:0;
  transform:rotate(42deg);
}
.checklist__label{font-size:.9rem;color:var(--ink-900)}
.checklist__meta{
  margin-left:auto;
  white-space:nowrap;
  font-family:var(--font-mono);
  font-size:.66rem;
  letter-spacing:.04em;
  color:var(--stone-500);
}

/* ---------- 14. 标签页 ---------- */
.tabs{
  display:flex;
  flex-wrap:wrap;
  gap:0;
  margin-bottom:20px;
  border-bottom:1px solid var(--line);
}
.tabs__btn{
  appearance:none;
  padding:10px 16px;
  border:0;
  border-bottom:2px solid transparent;
  background:transparent;
  font-family:var(--font-body);
  font-size:.86rem;
  color:var(--stone-500);
  cursor:pointer;
  transition:color .18s var(--ease),border-color .18s var(--ease);
}
.tabs__btn:hover{color:var(--ink-700)}
.tabs__btn[aria-selected="true"]{color:var(--ink-900);border-bottom-color:var(--copper-500)}
.tabs__panel{padding-top:4px}
.tabs__panel[hidden]{display:none}

/* ---------- 15. 折叠问答 ---------- */
.accordion{border-top:1px solid var(--line)}
.accordion__item{border-bottom:1px solid var(--line)}
.accordion__btn{
  display:flex;
  align-items:flex-start;
  justify-content:space-between;
  gap:16px;
  width:100%;
  padding:16px 4px;
  border:0;
  background:transparent;
  text-align:left;
  font-size:.98rem;
  color:var(--ink-900);
  cursor:pointer;
  transition:color .18s var(--ease);
}
.accordion__btn:hover{color:var(--ink-500)}
.accordion__btn::after{
  content:"+";
  flex:0 0 auto;
  font-family:var(--font-mono);
  color:var(--copper-500);
}
.accordion__btn[aria-expanded="true"]::after{content:"–"}
.accordion__panel{padding:0 4px 18px;font-size:.92rem;line-height:1.75;color:var(--ink-700)}
.accordion__panel[hidden]{display:none}

/* ---------- 16. 对照表 ---------- */
.table-wrap{overflow-x:auto;border:1px solid var(--line);background:var(--paper-50)}
.table{width:100%;min-width:520px;font-size:.88rem}
.table caption{
  caption-side:top;
  padding:10px 14px;
  text-align:left;
  font-family:var(--font-mono);
  font-size:.7rem;
  letter-spacing:.04em;
  color:var(--stone-500);
}
.table th,.table td{
  padding:10px 14px;
  border-bottom:1px solid var(--line);
  text-align:left;
  vertical-align:top;
}
.table thead th{
  background:var(--ink-700);
  color:var(--paper-50);
  font-weight:500;
  font-size:.8rem;
  letter-spacing:.04em;
}
.table tbody tr:nth-child(even){background:var(--paper-100)}
.table td.is-num{
  font-family:var(--font-mono);
  font-size:.78rem;
  color:var(--ink-500);
  white-space:nowrap;
}

/* ---------- 17. 框景与图像容器 ---------- */
.frame{
  position:relative;
  border:1px solid var(--line-strong);
  border-radius:2px;
  background:var(--paper-50);
}
.frame::before{
  content:"";
  position:absolute;
  inset:7px;
  border:1px solid rgba(180,136,75,.28);
  pointer-events:none;
}
.frame__tick{position:absolute;width:12px;height:12px;pointer-events:none}
.frame__tick--tl{top:-1px;left:-1px;border-top:2px solid var(--copper-500);border-left:2px solid var(--copper-500)}
.frame__tick--tr{top:-1px;right:-1px;border-top:2px solid var(--copper-500);border-right:2px solid var(--copper-500)}
.frame__tick--bl{bottom:-1px;left:-1px;border-bottom:2px solid var(--copper-500);border-left:2px solid var(--copper-500)}
.frame__tick--br{bottom:-1px;right:-1px;border-bottom:2px solid var(--copper-500);border-right:2px solid var(--copper-500)}

.media{
  position:relative;
  display:block;
  aspect-ratio:16/10;
  overflow:hidden;
  border:1px solid var(--line-strong);
  border-radius:2px;
  background:var(--ink-900);
}
.media img{width:100%;height:100%;object-fit:cover}
.media--wide{aspect-ratio:21/9}
.media--square{aspect-ratio:1/1}
.media--tall{aspect-ratio:4/5}
.media--blueprint{
  background-color:var(--ink-900);
  background-image:
    linear-gradient(rgba(224,199,154,.09) 1px,transparent 1px),
    linear-gradient(90deg,rgba(224,199,154,.09) 1px,transparent 1px);
  background-size:100% 28px,28px 100%;
  background-position:0 0,0 0;
}
.media__caption{
  margin-top:8px;
  font-family:var(--font-mono);
  font-size:.68rem;
  letter-spacing:.04em;
  color:var(--stone-500);
}
@media (max-width:640px){
  .media{aspect-ratio:4/3}
  .media--tall{aspect-ratio:1/1}
}

/* ---------- 18. 显现动画 ---------- */
[data-reveal]{
  opacity:0;
  transform:translateY(8px);
  transition:opacity .26s var(--ease),transform .26s var(--ease);
}
[data-reveal].is-visible{opacity:1;transform:none}

/* ---------- 19. 返回顶部与复制按钮 ---------- */
.to-top{
  position:fixed;
  right:24px;
  bottom:24px;
  z-index:70;
  display:inline-flex;
  align-items:center;
  gap:8px;
  padding:9px 14px;
  border:1px solid var(--copper-500);
  border-radius:2px;
  background:var(--ink-900);
  color:var(--paper-50);
  font-family:var(--font-mono);
  font-size:.7rem;
  letter-spacing:.06em;
  cursor:pointer;
  opacity:0;
  visibility:hidden;
  transform:translateY(6px);
  transition:opacity .2s var(--ease),transform .2s var(--ease),visibility .2s linear,background .18s var(--ease);
}
.to-top[data-visible="true"]{opacity:1;visibility:visible;transform:none}
.to-top:hover{background:var(--ink-700)}

.copy-btn{
  display:inline-flex;
  align-items:center;
  gap:6px;
  padding:5px 10px;
  border:1px solid var(--line-strong);
  border-radius:2px;
  background:var(--paper-50);
  color:var(--ink-700);
  font-family:var(--font-mono);
  font-size:.68rem;
  letter-spacing:.04em;
  cursor:pointer;
  transition:border-color .18s var(--ease),color .18s var(--ease);
}
.copy-btn:hover{border-color:var(--copper-500);color:var(--ink-900)}
.copy-btn[data-copied="true"]{border-color:var(--cinnabar-600);color:var(--cinnabar-600)}

@media (max-width:640px){
  .to-top{right:16px;bottom:16px}
}

/* ---------- 20. 降低动效 ---------- */
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
  }
  [data-reveal]{opacity:1;transform:none}
}