/* ============================================================
   互博HOOBALL · 站内索引图鉴
   共享样式 /assets/site.css
   ============================================================ */

/* ---------- 1. 变量 ---------- */
:root{
  --ink:#0B2E28;
  --ink-deep:#071E1A;
  --ink-mid:#14524A;
  --wash:#E7EDE9;
  --paper:#F4F8F6;
  --cyan:#17E0C8;
  --cyan-dark:#0FA79A;
  --amber:#FF8A3D;
  --neutral:#9DB3AB;
  --text-ink:#10201D;

  --line:rgba(157,179,171,.22);
  --line-strong:rgba(23,224,200,.45);
  --grid-line:rgba(157,179,171,.07);

  --cut:18px;
  --skew:-12deg;

  --display:"Archivo Narrow","Oswald","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,sans-serif;
  --body:"PingFang SC","Hiragino Sans GB","Source Han Sans SC","Noto Sans CJK SC","Microsoft YaHei",system-ui,-apple-system,sans-serif;
  --mono:ui-monospace,"SFMono-Regular","JetBrains Mono",Menlo,Consolas,"Liberation Mono",monospace;

  --wrap:1200px;
  --shadow-panel:0 26px 64px -34px rgba(0,0,0,.8);
  --ease:cubic-bezier(.22,.61,.36,1);
}

/* ---------- 2. 重置 ---------- */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%}
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%}
a{color:inherit;text-decoration:none}
button{font:inherit;color:inherit;background:none;border:0;cursor:pointer}
table{border-collapse:collapse;width:100%}
:focus-visible{outline:2px solid var(--cyan);outline-offset:3px}
::selection{background:var(--cyan);color:#04231F}

/* ---------- 3. 中文排版基底 ---------- */
body{
  margin:0;
  background:var(--ink);
  color:var(--paper);
  font-family:var(--body);
  font-size:17px;
  line-height:1.75;
  letter-spacing:.005em;
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
h1,h2,h3,h4{font-family:var(--display);font-weight:800;line-height:1.2;letter-spacing:-.005em}
h1{font-size:clamp(2.2rem,5.5vw,4rem)}
h2{font-size:clamp(1.5rem,3.2vw,2.3rem)}
h3{font-size:clamp(1.1rem,2vw,1.35rem)}
p{text-wrap:pretty}
.mono{font-family:var(--mono);font-size:.84em;letter-spacing:.05em}
.visually-hidden{position:absolute!important;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap;border:0}
#main-content{display:block;scroll-margin-top:96px}

/* ---------- 4. 容器与栅格 ---------- */
.wrap{width:min(var(--wrap),100% - 2.5rem);margin-inline:auto}
.grid-12{display:grid;grid-template-columns:repeat(12,minmax(0,1fr));gap:clamp(1rem,2vw,1.5rem)}
.col-4{grid-column:span 4}
.col-5{grid-column:span 5}
.col-6{grid-column:span 6}
.col-7{grid-column:span 7}
.col-8{grid-column:span 8}
.col-12{grid-column:span 12}

/* ---------- 5. 切角 / 斜线 / 轨迹等通用图形 ---------- */
.cut{clip-path:polygon(0 0,calc(100% - var(--cut)) 0,100% var(--cut),100% 100%,var(--cut) 100%,0 calc(100% - var(--cut)))}
.slash{display:inline-block;width:34px;height:3px;background:var(--amber);transform:skewX(var(--skew))}
.hairline{height:1px;border:0;background:linear-gradient(90deg,rgba(157,179,171,.4),transparent);margin:0}
.track{position:relative;height:1px;background:var(--line);margin-block:clamp(1.4rem,3vw,2.2rem)}
.track::before,.track::after{content:"";position:absolute;top:-3px;width:7px;height:7px;background:var(--cyan)}
.track::before{left:0}
.track::after{right:0;background:var(--amber)}

/* ---------- 6. 跳转链接 ---------- */
.skip-link{
  position:fixed;top:.6rem;left:.6rem;z-index:120;
  padding:.65rem 1.1rem;
  background:var(--cyan);color:#04231F;
  font-weight:700;font-size:.92rem;
  clip-path:polygon(0 0,calc(100% - 10px) 0,100% 10px,100% 100%,10px 100%,0 calc(100% - 10px));
  transform:translateY(-180%);
  transition:transform .2s var(--ease);
}
.skip-link:focus{transform:none}

/* ---------- 7. 顶部滚动进度 ---------- */
.scroll-progress{position:fixed;top:0;left:0;right:0;height:3px;z-index:90;pointer-events:none}
.scroll-progress__bar{
  display:block;height:100%;width:100%;
  transform:scaleX(0);transform-origin:0 50%;
  background:linear-gradient(90deg,var(--cyan),var(--amber));
  transition:transform .1s linear;
}

/* ---------- 8. 页头：左右分置 + 中央索引状态位 ---------- */
.site-header{
  position:sticky;top:0;z-index:60;
  background-color:#0A2A25;
  background-image:
    linear-gradient(var(--grid-line) 1px,transparent 1px),
    linear-gradient(90deg,var(--grid-line) 1px,transparent 1px),
    linear-gradient(180deg,#0C322B 0%,#0A2A25 62%,#082420 100%);
  background-size:46px 46px,46px 46px,100% 100%;
  border-bottom:1px solid var(--line);
  transition:box-shadow .25s var(--ease),border-color .25s var(--ease);
}
.site-header::before{
  content:"";position:absolute;left:0;right:0;top:0;height:2px;
  background:linear-gradient(90deg,var(--cyan),rgba(23,224,200,0) 55%,var(--amber));
  opacity:.75;pointer-events:none;
}
.site-header[data-scrolled]{box-shadow:0 20px 44px -30px rgba(0,0,0,.95);border-bottom-color:var(--line-strong)}

.header-shell{
  position:relative;
  width:min(var(--wrap),100% - 2.5rem);
  margin-inline:auto;
  min-height:74px;
  display:flex;
  align-items:center;
  gap:clamp(.8rem,2.4vw,2rem);
  padding-block:.65rem;
}

/* 品牌区（左端） */
.brand-block{display:flex;align-items:center;flex:0 0 auto;min-width:0}
.brand-mark{display:flex;align-items:center;gap:.7rem}
.brand-mark__glyph{
  flex:0 0 auto;
  display:grid;place-items:center;
  width:40px;height:40px;
  font-family:var(--display);font-weight:800;font-size:1.15rem;
  color:#04231F;background:var(--cyan);
  clip-path:polygon(0 0,calc(100% - 12px) 0,100% 12px,100% 100%,12px 100%,0 calc(100% - 12px));
}
.brand-mark__text{display:flex;flex-direction:column;line-height:1.25;min-width:0}
.brand-mark__name{font-family:var(--display);font-weight:800;font-size:1.14rem;letter-spacing:.03em;color:var(--paper)}
.brand-mark__tagline{font-size:12px;color:var(--neutral);letter-spacing:.02em}
.brand-mark:hover .brand-mark__name{color:var(--cyan)}

/* 索引状态位（中部） */
.index-status{
  display:flex;align-items:center;gap:.9rem;
  margin-inline:auto;
  padding:.32rem .9rem;
  border-left:1px solid var(--line);
  border-right:1px solid var(--line);
  font-family:var(--mono);
  font-size:11.5px;
  letter-spacing:.06em;
  color:var(--neutral);
  white-space:nowrap;
}
.index-status__item{display:inline-flex;align-items:baseline;gap:.4rem}
.index-status__k{opacity:.78}
.index-status__v{color:var(--cyan);font-weight:600}
.index-status__link{
  color:var(--amber);
  border-bottom:1px dashed rgba(255,138,61,.5);
  padding-bottom:1px;
  transition:color .18s var(--ease),border-color .18s var(--ease);
}
.index-status__link:hover{color:#FFB079;border-bottom-color:#FFB079}

/* 栏目区（右端） */
.site-nav{display:flex;align-items:center;gap:.4rem;flex:0 1 auto}
.site-nav__list{display:flex;align-items:center;gap:.1rem}
.site-nav__item{display:flex}
.site-nav__link{
  position:relative;
  display:inline-block;
  padding:.5rem .68rem;
  font-size:.94rem;
  color:rgba(244,248,246,.8);
  transition:color .18s var(--ease);
}
.site-nav__link::after{
  content:"";position:absolute;left:.68rem;right:.68rem;bottom:.28rem;height:2px;
  background:var(--cyan);transform:scaleX(0);transform-origin:left;
  transition:transform .18s var(--ease);
}
.site-nav__link:hover{color:var(--paper)}
.site-nav__link:hover::after{transform:scaleX(1)}
.site-nav__link[aria-current="page"]{color:var(--cyan)}
.site-nav__link[aria-current="page"]::after{transform:scaleX(1)}
.site-nav__cta{margin-left:.7rem}

/* 移动导航按钮 */
.nav-toggle{
  display:none;position:relative;flex:0 0 auto;
  width:44px;height:44px;
  background:rgba(23,224,200,.07);
  border:1px solid var(--line-strong);
  clip-path:polygon(0 0,calc(100% - 10px) 0,100% 10px,100% 100%,10px 100%,0 calc(100% - 10px));
  transition:background-color .18s var(--ease);
}
.nav-toggle:hover{background:rgba(23,224,200,.16)}
.nav-toggle__bar{
  position:absolute;left:12px;right:12px;height:2px;background:var(--cyan);
  transition:transform .22s var(--ease),opacity .18s var(--ease);
}
.nav-toggle__bar:nth-child(1){top:16px}
.nav-toggle__bar:nth-child(2){top:21px}
.nav-toggle__bar:nth-child(3){top:26px}
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(1){transform:translateY(5px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(2){opacity:0}
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(3){transform:translateY(-5px) rotate(-45deg)}

/* ---------- 9. 按钮 ---------- */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:.5rem;
  padding:.78rem 1.3rem;
  font-family:var(--body);font-size:.95rem;font-weight:700;letter-spacing:.02em;
  border:1px solid transparent;
  clip-path:polygon(0 0,calc(100% - 12px) 0,100% 12px,100% 100%,12px 100%,0 calc(100% - 12px));
  transition:background-color .18s var(--ease),color .18s var(--ease),border-color .18s var(--ease),transform .18s var(--ease);
}
.btn:hover{transform:translateY(-1px)}
.btn:active{transform:none}
.btn--primary{background:var(--cyan);color:#04231F}
.btn--primary:hover{background:#40EDD7}
.btn--ghost{color:var(--cyan);border-color:var(--line-strong);background:rgba(23,224,200,.06)}
.btn--ghost:hover{background:rgba(23,224,200,.16)}
.btn--amber{background:var(--amber);color:#2B1405}
.btn--amber:hover{background:#FFA264}
.btn--quiet{color:var(--paper);border-color:var(--line)}
.btn--quiet:hover{border-color:var(--line-strong);color:var(--cyan)}

/* ---------- 10. 区块 ---------- */
.section{padding-block:clamp(3rem,7vw,5.5rem);position:relative}
.section--tight{padding-block:clamp(2rem,4vw,3rem)}
.section--wash{background:var(--wash);color:var(--text-ink)}
.section--deep{background:var(--ink-deep)}
.section__head{margin-bottom:clamp(1.6rem,3vw,2.4rem)}
.section__eyebrow{
  display:inline-flex;align-items:center;gap:.6rem;
  margin-bottom:.9rem;
  font-family:var(--mono);font-size:12px;letter-spacing:.16em;text-transform:uppercase;
  color:var(--cyan);
}
.section__eyebrow::before{content:"";width:22px;height:2px;background:var(--amber);transform:skewX(var(--skew))}
.section__title{margin-bottom:.6rem}
.section__lead{max-width:64ch;color:rgba(244,248,246,.78)}
.section--wash .section__eyebrow{color:var(--cyan-dark)}
.section--wash .section__lead{color:rgba(16,32,29,.76)}

/* ---------- 11. 面板（堆叠画板） ---------- */
.panel{
  position:relative;
  padding:clamp(1.2rem,2.6vw,2rem);
  background:linear-gradient(160deg,var(--ink-mid),#0E3F38 58%,#0B322C);
  border:1px solid var(--line);
  box-shadow:var(--shadow-panel);
}
.panel--cut{clip-path:polygon(0 0,calc(100% - var(--cut)) 0,100% var(--cut),100% 100%,var(--cut) 100%,0 calc(100% - var(--cut)))}
.panel--deep{background:linear-gradient(160deg,#0A2A25,#061A17)}
.panel--quiet{background:rgba(244,248,246,.05);box-shadow:none}
.panel--accent{border-color:var(--line-strong)}
.panel--wash{background:var(--paper);color:var(--text-ink);border-color:rgba(16,32,29,.1);box-shadow:0 20px 44px -34px rgba(11,46,40,.5)}
.panel__title{font-size:1.15rem;margin-bottom:.35rem}
.panel__meta{font-family:var(--mono);font-size:12px;letter-spacing:.08em;color:var(--neutral)}
.section--wash .panel__meta{color:#5E7A72}

/* ---------- 12. 档案卡 ---------- */
.index-card{
  position:relative;display:flex;flex-direction:column;gap:.6rem;
  padding:clamp(1rem,2vw,1.4rem);
  background:rgba(244,248,246,.045);
  border:1px solid var(--line);
  transition:border-color .18s var(--ease),transform .18s var(--ease),background-color .18s var(--ease);
}
.index-card:hover{border-color:var(--line-strong);background:rgba(23,224,200,.07);transform:translateY(-2px)}
.index-card__no{font-family:var(--mono);font-size:12px;letter-spacing:.14em;color:var(--amber)}
.index-card__title{font-family:var(--display);font-weight:800;font-size:1.18rem;color:var(--paper)}
.index-card__desc{font-size:.94rem;color:rgba(244,248,246,.72)}
.index-card__meta{margin-top:auto;font-family:var(--mono);font-size:12px;letter-spacing:.06em;color:var(--neutral)}
.section--wash .index-card{background:rgba(16,32,29,.035);border-color:rgba(16,32,29,.12)}
.section--wash .index-card:hover{background:rgba(15,167,154,.1);border-color:rgba(15,167,154,.5)}
.section--wash .index-card__title{color:var(--text-ink)}
.section--wash .index-card__desc{color:rgba(16,32,29,.72)}
.section--wash .index-card__meta{color:#5E7A72}
.section--wash .index-card__no{color:#C9601F}

/* ---------- 13. 标签 ---------- */
.tag{
  display:inline-flex;align-items:center;gap:.4rem;
  padding:.22rem .55rem;
  font-family:var(--mono);font-size:11.5px;letter-spacing:.08em;
  color:var(--neutral);
  background:rgba(244,248,246,.04);
  border:1px solid var(--line);
}
.tag--cyan{color:var(--cyan);border-color:rgba(23,224,200,.42);background:rgba(23,224,200,.1)}
.tag--amber{color:var(--amber);border-color:rgba(255,138,61,.45);background:rgba(255,138,61,.1)}
.tag--mute{color:var(--neutral)}
.tag-row{display:flex;flex-wrap:wrap;gap:.45rem}
.section--wash .tag{color:#4A655D;border-color:rgba(16,32,29,.14);background:rgba(16,32,29,.03)}
.section--wash .tag--cyan{color:#0A6C61;border-color:rgba(15,167,154,.45);background:rgba(15,167,154,.12)}
.section--wash .tag--amber{color:#B85A19;border-color:rgba(255,138,61,.5);background:rgba(255,138,61,.14)}

/* ---------- 14. 面包屑 ---------- */
.breadcrumbs{font-family:var(--mono);font-size:12px;letter-spacing:.05em;color:var(--neutral);margin-bottom:clamp(1.2rem,3vw,2rem)}
.breadcrumbs__list{display:flex;flex-wrap:wrap;align-items:center;gap:.5rem}
.breadcrumbs__list li{display:flex;align-items:center;gap:.5rem}
.breadcrumbs__list li + li::before{content:"/";color:rgba(157,179,171,.5)}
.breadcrumbs a{color:var(--neutral);transition:color .18s var(--ease)}
.breadcrumbs a:hover{color:var(--cyan)}
.breadcrumbs [aria-current="page"]{color:var(--cyan)}
.section--wash .breadcrumbs{color:#5E7A72}
.section--wash .breadcrumbs a{color:#5E7A72}
.section--wash .breadcrumbs a:hover{color:var(--cyan-dark)}
.section--wash .breadcrumbs [aria-current="page"]{color:var(--cyan-dark)}

/* ---------- 15. 正文排版 ---------- */
.prose{max-width:72ch}
.prose h2{margin:2.2rem 0 .7rem}
.prose h3{margin:1.6rem 0 .5rem}
.prose p{margin-bottom:1.05em}
.prose ul{margin:0 0 1.1em;display:grid;gap:.5rem}
.prose li{position:relative;padding-left:1.1rem}
.prose li::before{content:"";position:absolute;left:0;top:.72em;width:6px;height:6px;background:var(--cyan);transform:skewX(var(--skew))}
.prose a{color:var(--cyan);border-bottom:1px solid rgba(23,224,200,.35)}
.prose a:hover{color:#6FF3E2}
.prose blockquote{border-left:2px solid var(--amber);padding-left:1rem;color:rgba(244,248,246,.85)}
.section--wash .prose a{color:var(--cyan-dark);border-bottom-color:rgba(15,167,154,.4)}
.section--wash .prose a:hover{color:#0A6C61}
.section--wash .prose li::before{background:var(--cyan-dark)}

/* ---------- 16. 图片容器基础规则 ---------- */
.media-frame{
  position:relative;overflow:hidden;
  aspect-ratio:16 / 9;
  background:radial-gradient(130% 120% at 8% 0%,#14524A,#082420 72%);
  border:1px solid var(--line);
}
.media-frame--cut{clip-path:polygon(0 0,calc(100% - var(--cut)) 0,100% var(--cut),100% 100%,var(--cut) 100%,0 calc(100% - var(--cut)))}
.media-frame--wide{aspect-ratio:21 / 9}
.media-frame--tall{aspect-ratio:4 / 5}
.media-frame--square{aspect-ratio:1 / 1}
.media-frame > img{width:100%;height:100%;object-fit:cover;position:relative;z-index:1}
.media-frame__grid{
  position:absolute;inset:0;z-index:2;pointer-events:none;
  background-image:
    linear-gradient(var(--grid-line) 1px,transparent 1px),
    linear-gradient(90deg,var(--grid-line) 1px,transparent 1px);
  background-size:38px 38px;
}
.media-frame__rail{
  position:absolute;top:0;right:22px;z-index:3;width:2px;height:42%;
  background:linear-gradient(180deg,var(--amber),rgba(255,138,61,0));
  transform:skewX(var(--skew));pointer-events:none;
}
.media-frame__cap{
  position:absolute;left:0;bottom:0;z-index:4;max-width:100%;
  padding:.45rem .85rem;
  background:rgba(6,26,23,.88);
  color:var(--cyan);
  font-family:var(--mono);font-size:11.5px;letter-spacing:.06em;
}
.media-frame--empty::after{
  content:attr(data-slot);
  position:absolute;left:1rem;right:1rem;bottom:50%;z-index:3;
  text-align:center;
  font-family:var(--mono);font-size:12px;letter-spacing:.12em;
  color:rgba(157,179,171,.72);
}

/* ---------- 17. 滚动显现 ---------- */
html.has-js [data-reveal]{
  opacity:0;
  transform:translateY(18px);
  transition:opacity .55s var(--ease),transform .55s var(--ease);
  transition-delay:var(--reveal-delay,0ms);
  will-change:opacity,transform;
}
html.has-js [data-reveal].is-visible{opacity:1;transform:none}

/* ---------- 18. 返回顶部 ---------- */
.to-top{
  position:fixed;right:1.1rem;bottom:1.1rem;z-index:70;
  width:46px;height:46px;
  display:grid;place-items:center;
  background:var(--ink-mid);color:var(--cyan);
  border:1px solid var(--line-strong);
  font-family:var(--mono);font-size:15px;line-height:1;
  clip-path:polygon(0 0,calc(100% - 10px) 0,100% 10px,100% 100%,10px 100%,0 calc(100% - 10px));
  opacity:0;visibility:hidden;transform:translateY(10px);
  transition:opacity .2s var(--ease),transform .2s var(--ease),visibility .2s var(--ease),background-color .18s var(--ease);
}
.to-top[data-visible]{opacity:1;visibility:visible;transform:none}
.to-top:hover{background:#1B6157}

/* ---------- 19. 页脚 ---------- */
.site-footer{
  position:relative;
  background-color:var(--ink-deep);
  background-image:
    linear-gradient(var(--grid-line) 1px,transparent 1px),
    linear-gradient(90deg,var(--grid-line) 1px,transparent 1px);
  background-size:46px 46px;
  border-top:1px solid var(--line);
  color:var(--paper);
}
.site-footer::before{
  content:"";position:absolute;top:0;left:0;width:min(320px,60%);height:2px;
  background:linear-gradient(90deg,var(--amber),rgba(255,138,61,0));
}
.footer-shell{
  position:relative;
  width:min(var(--wrap),100% - 2.5rem);
  margin-inline:auto;
  padding-block:clamp(2.4rem,5vw,3.6rem) 1.6rem;
  display:grid;
  grid-template-columns:minmax(230px,1fr) minmax(0,1.9fr);
  gap:clamp(1.6rem,4vw,3rem);
}
.footer-brand__mark{
  display:inline-block;
  margin-bottom:.9rem;padding-bottom:.22rem;
  font-family:var(--display);font-weight:800;font-size:1.35rem;letter-spacing:.02em;
  color:var(--paper);
  border-bottom:2px solid var(--cyan);
  transition:color .18s var(--ease),border-color .18s var(--ease);
}
.footer-brand__mark:hover{color:var(--cyan);border-bottom-color:var(--amber)}
.footer-brand__line{max-width:34ch;font-size:.95rem;color:rgba(244,248,246,.72)}
.footer-brand__meta{margin-top:1rem;font-family:var(--mono);font-size:12px;letter-spacing:.1em;color:var(--neutral)}
.footer-cols{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:clamp(1rem,3vw,2rem)}
.footer-col__title{
  display:flex;align-items:center;gap:.5rem;
  margin-bottom:.9rem;
  font-family:var(--mono);font-size:12px;font-weight:400;letter-spacing:.16em;text-transform:uppercase;
  color:var(--cyan);
}
.footer-col__title::before{content:"";width:14px;height:2px;background:var(--amber);transform:skewX(var(--skew))}
.footer-col__list{display:grid;gap:.55rem}
.footer-col__link{
  font-size:.95rem;color:rgba(244,248,246,.72);
  border-bottom:1px solid transparent;
  transition:color .18s var(--ease),border-color .18s var(--ease);
}
.footer-col__link:hover{color:var(--cyan);border-bottom-color:rgba(23,224,200,.4)}
.footer-col__link--mono{font-family:var(--mono);font-size:.85rem;letter-spacing:.02em;word-break:break-all}
.footer-col__item--plain{font-size:.9rem;line-height:1.65;color:rgba(244,248,246,.6)}
.footer-bottom{
  grid-column:1 / -1;
  margin-top:clamp(1.6rem,4vw,2.4rem);
  padding-top:1.2rem;
  border-top:1px solid var(--line);
  display:flex;flex-wrap:wrap;gap:.6rem 1.6rem;
  align-items:baseline;justify-content:space-between;
}
.footer-legal{max-width:62ch;font-size:.86rem;color:rgba(244,248,246,.6)}
.footer-meta{font-family:var(--mono);font-size:12px;letter-spacing:.06em;color:var(--neutral)}
.footer-icp{color:var(--neutral)}

/* ---------- 20. 响应式 ---------- */
@media (max-width:1180px){
  .index-status{display:none}
  .site-nav{margin-left:auto}
}

@media (max-width:960px){
  .col-4,.col-5,.col-6,.col-7,.col-8{grid-column:span 12}
  .footer-shell{grid-template-columns:1fr}
  .footer-cols{grid-template-columns:repeat(2,minmax(0,1fr));gap:1.4rem}
}

@media (max-width:900px){
  .header-shell{
    flex-wrap:wrap;
    gap:.5rem;
    min-height:0;
    padding-block:.6rem;
  }
  .brand-block{flex:1 1 auto;min-width:0}
  .brand-mark__tagline{display:none}
  .index-status{display:none}
  .nav-toggle{display:block}

  .site-nav{
    order:5;
    flex:1 0 100%;
    display:none;
    margin-top:.35rem;
    padding-top:.85rem;
    border-top:1px solid var(--line);
  }
  .site-nav[data-open]{display:block;animation:navDrop .22s var(--ease)}
  .site-header[data-open]{border-bottom-color:var(--line-strong)}

  .site-nav__list{
    display:flex;
    flex-wrap:nowrap;
    gap:.45rem;
    overflow-x:auto;
    padding-bottom:.55rem;
    -webkit-overflow-scrolling:touch;
    scrollbar-width:thin;
  }
  .site-nav__list::-webkit-scrollbar{height:4px}
  .site-nav__list::-webkit-scrollbar-track{background:rgba(244,248,246,.06)}
  .site-nav__list::-webkit-scrollbar-thumb{background:rgba(23,224,200,.45)}
  .site-nav__link{
    flex:0 0 auto;
    white-space:nowrap;
    padding:.45rem .82rem;
    border:1px solid var(--line);
    background:rgba(244,248,246,.04);
  }
  .site-nav__link::after{display:none}
  .site-nav__link:hover{background:rgba(244,248,246,.09)}
  .site-nav__link[aria-current="page"]{
    border-color:var(--line-strong);
    background:rgba(23,224,200,.14);
  }
  .site-nav__cta{display:flex;width:100%;margin:.7rem 0 0}
}

@keyframes navDrop{
  from{opacity:0;transform:translateY(-8px)}
  to{opacity:1;transform:none}
}

@media (max-width:640px){
  body{font-size:16px}
  .wrap,.header-shell,.footer-shell{width:min(var(--wrap),100% - 1.6rem)}
  .footer-cols{grid-template-columns:1fr}
  .footer-bottom{flex-direction:column;align-items:flex-start}
  .to-top{right:.8rem;bottom:.8rem;width:42px;height:42px}
}

/* ---------- 21. 动效降级 ---------- */
@media (prefers-reduced-motion: reduce){
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
    scroll-behavior:auto !important;
  }
  html.has-js [data-reveal]{opacity:1;transform:none}
  .skip-link{transition:none}
}