/* ============================================================
   美高主页 · 共享样式表 /assets/site.css
   高原青蓝 · 青海湖深蓝 · 油菜花暖金 · 岩灰 · 雪白
   ============================================================ */

/* ---------- 1. Reset ---------- */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body{margin:0;padding:0}
h1,h2,h3,h4,h5,p,ul,ol,li,figure,blockquote,dl,dd{margin:0;padding:0}
ul,ol{list-style:none}
a{color:inherit;text-decoration:none}
button,input,select,textarea{font:inherit;color:inherit}
button{background:none;border:0;cursor:pointer}
img,svg{display:block;max-width:100%}
table{border-collapse:collapse;width:100%}

/* ---------- 2. Tokens ---------- */
:root{
  --c-primary:#16697F;
  --c-deep:#0C3547;
  --c-mid:#3E92AC;
  --c-mist:#DCE9EF;
  --c-gold:#DFA22B;
  --c-gold-lt:#F5D795;
  --c-stone:#59626F;
  --c-ink:#262C35;
  --c-snow:#FBFAF7;
  --c-indigo:#2E3F6B;

  --font-sans:"Noto Sans SC","Source Han Sans SC","PingFang SC","Microsoft YaHei",system-ui,-apple-system,sans-serif;
  --font-mono:"JetBrains Mono","SFMono-Regular",Consolas,"Liberation Mono",monospace;

  --header-h:78px;
  --gutter:clamp(20px,4vw,56px);
  --maxw:1320px;

  --line-hair:1px solid rgba(89,98,111,.26);
  --shadow-hard:6px 6px 0 rgba(12,53,71,.14);
  --shadow-float:10px 12px 0 rgba(12,53,71,.18);
}
@media (max-width:980px){:root{--header-h:64px}}

/* ---------- 3. Base / 中文排版 ---------- */
body{
  font-family:var(--font-sans);
  font-size:16.5px;
  line-height:1.75;
  font-weight:400;
  color:var(--c-ink);
  background:var(--c-snow);
  -webkit-font-smoothing:antialiased;
  overflow-x:hidden;
}
p{max-width:38em}
h1,h2,h3,h4{line-height:1.25;font-weight:600;letter-spacing:0}
#main-content{padding-top:var(--header-h)}
.under-nav{margin-top:calc(var(--header-h) * -1)}
::selection{background:var(--c-gold-lt);color:var(--c-ink)}

:focus-visible{outline:3px solid var(--c-gold);outline-offset:2px}
.site-footer :focus-visible{outline-color:var(--c-gold-lt)}

.visually-hidden{position:absolute!important;width:1px;height:1px;overflow:hidden;clip:rect(0 0 0 0);white-space:nowrap}
.mono{font-family:var(--font-mono);font-size:.93em;letter-spacing:.06em}

/* ---------- 4. 布局容器 ---------- */
.container{width:100%;max-width:var(--maxw);margin-inline:auto;padding-inline:var(--gutter)}
.container--narrow{max-width:820px}
.container--wide{max-width:1560px}

/* ---------- 5. 文字工具 ---------- */
.display{font-size:clamp(34px,6vw,74px);font-weight:300;line-height:1.05;letter-spacing:-.02em}
.display strong{font-weight:600}
.title-lg{font-size:clamp(26px,3.4vw,44px);font-weight:400;line-height:1.18;letter-spacing:-.01em}
.eyebrow{
  display:inline-block;font-family:var(--font-mono);font-size:11.5px;letter-spacing:.22em;
  color:var(--c-primary);border-left:3px solid var(--c-gold);padding-left:10px;margin-bottom:16px;
}
.lede{font-size:clamp(16px,1.6vw,18.5px);color:var(--c-stone);line-height:1.8}
.key-path{font-weight:700;border-bottom:3px solid var(--c-gold);padding-bottom:1px}
.text-stone{color:var(--c-stone)}
.text-gold{color:var(--c-gold)}

/* ---------- 6. 按钮 ---------- */
.btn{
  display:inline-flex;align-items:center;gap:8px;
  padding:13px 22px;font-size:14.5px;font-weight:600;letter-spacing:.02em;
  border:2px solid var(--c-ink);background:var(--c-snow);color:var(--c-ink);
  box-shadow:4px 4px 0 rgba(12,53,71,.18);
  transition:transform .18s ease,box-shadow .18s ease,background-color .18s ease,color .18s ease;
}
.btn:hover{transform:translate(-2px,-2px);box-shadow:7px 7px 0 rgba(12,53,71,.22)}
.btn:active{transform:translate(1px,1px);box-shadow:2px 2px 0 rgba(12,53,71,.22)}
.btn--primary{background:var(--c-gold);border-color:var(--c-ink);color:var(--c-ink)}
.btn--deep{background:var(--c-deep);border-color:var(--c-deep);color:var(--c-snow);box-shadow:4px 4px 0 rgba(223,162,43,.5)}
.btn--ghost{background:transparent;border-color:currentColor;box-shadow:none}
.btn--ghost:hover{background:rgba(22,105,127,.08)}
.btn--quiet{
  border-color:transparent;background:transparent;box-shadow:none;padding-inline:0;
  text-decoration:underline;text-decoration-color:var(--c-gold);text-decoration-thickness:2px;text-underline-offset:5px;
}
.btn--quiet:hover{transform:none;color:var(--c-primary);box-shadow:none}

/* ---------- 7. 面包屑 ---------- */
.breadcrumb{
  display:flex;flex-wrap:wrap;align-items:center;gap:4px;
  font-family:var(--font-mono);font-size:12px;letter-spacing:.08em;
  color:var(--c-stone);margin-bottom:clamp(20px,3vw,32px);
}
.breadcrumb__item{display:inline-flex;align-items:center}
.breadcrumb__item::after{content:"/";margin-inline:8px;color:rgba(89,98,111,.45)}
.breadcrumb__item:last-child::after{content:"";margin:0}
.breadcrumb a:hover{color:var(--c-primary)}

/* ---------- 8. 章节 ---------- */
.section{padding-block:clamp(48px,7vw,96px)}
.section--mist{background:var(--c-mist)}
.section--deep{background:var(--c-deep);color:var(--c-snow)}
.section__head{max-width:58ch;margin-bottom:clamp(24px,4vw,48px)}
.section__title{font-size:clamp(24px,3.2vw,40px);font-weight:400;letter-spacing:-.01em;line-height:1.2}
.section__lead{margin-top:14px;color:var(--c-stone);font-size:16px}
.section--deep .section__lead{color:rgba(251,250,247,.76)}
.section--deep .eyebrow{color:var(--c-gold-lt)}

/* ---------- 9. Bento 网格 ---------- */
.bento{display:grid;grid-template-columns:repeat(12,minmax(0,1fr));gap:clamp(18px,2.2vw,28px)}
.cell-1x1{grid-column:span 3}
.cell-2x1{grid-column:span 6}
.cell-2x2{grid-column:span 6}
.cell-3x2{grid-column:span 9}
@media (min-width:901px){
  .bento{grid-auto-rows:minmax(160px,auto)}
  .cell-2x2,.cell-3x2{grid-row:span 2}
}

/* ---------- 10. 卡片 ---------- */
.card{
  position:relative;display:flex;flex-direction:column;gap:12px;height:100%;
  background:var(--c-snow);border:2px solid var(--c-ink);
  padding:clamp(20px,2.4vw,32px);box-shadow:var(--shadow-hard);
  transition:transform .24s ease,box-shadow .24s ease;
}
.card:hover{transform:translateY(-2px);box-shadow:var(--shadow-float)}
.card--mist{background:var(--c-mist);border-color:var(--c-primary)}
.card--primary{background:var(--c-primary);border-color:var(--c-deep);color:var(--c-snow)}
.card--deep{background:var(--c-deep);border-color:var(--c-deep);color:var(--c-snow)}
.card--gold{background:var(--c-gold-lt);border-color:var(--c-ink);color:var(--c-ink)}
.card__index{font-family:var(--font-mono);font-size:11.5px;letter-spacing:.18em;color:var(--c-gold)}
.card--gold .card__index{color:var(--c-indigo)}
.card--deep .card__index,.card--primary .card__index{color:var(--c-gold-lt)}
.card__title{font-size:clamp(18px,1.6vw,23px);font-weight:600;line-height:1.32}
.card__text{font-size:15px;line-height:1.75;color:var(--c-stone)}
.card--deep .card__text,.card--primary .card__text{color:rgba(251,250,247,.78)}
.card__foot{margin-top:auto;display:flex;flex-wrap:wrap;align-items:center;gap:12px}

/* ---------- 11. 标签 / 元信息 ---------- */
.meta-row{display:flex;flex-wrap:wrap;align-items:center;gap:10px}
.tag{
  display:inline-flex;align-items:center;gap:6px;padding:4px 10px;
  font-family:var(--font-mono);font-size:11.5px;letter-spacing:.1em;
  border:1.5px solid currentColor;background:transparent;color:var(--c-stone);
}
.tag--gold{background:var(--c-gold-lt);border-color:var(--c-gold);color:var(--c-ink)}
.tag--primary{background:var(--c-mist);border-color:var(--c-mid);color:var(--c-primary)}

/* ---------- 12. 路径索引 ---------- */
.index-card{
  border:2px solid var(--c-ink);background:var(--c-snow);
  box-shadow:var(--shadow-hard);padding:20px 22px;
}
.index-card__title{
  font-family:var(--font-mono);font-size:11.5px;letter-spacing:.18em;
  color:var(--c-stone);margin-bottom:14px;
}
.index-list{display:grid;gap:2px}
.index-list a{
  display:flex;align-items:baseline;justify-content:space-between;gap:14px;
  padding:10px 12px;font-size:14.5px;border-left:3px solid transparent;
  transition:background-color .18s ease,border-color .18s ease,color .18s ease;
}
.index-list a:hover{background:var(--c-mist);border-left-color:var(--c-gold)}
.index-list a[aria-current="page"]{border-left-color:var(--c-gold);font-weight:600;color:var(--c-primary)}
.index-list .mono{color:var(--c-stone);font-size:11.5px;white-space:nowrap}
.sidebar-sticky{position:sticky;top:calc(var(--header-h) + 24px)}

/* ---------- 13. 图片 / 视觉容器 ---------- */
.media{
  position:relative;width:100%;overflow:hidden;
  border:2px solid var(--c-ink);background:var(--c-mist);
  box-shadow:var(--shadow-hard);
}
.media__inner{position:absolute;inset:0;display:block}
.media__inner img{width:100%;height:100%;object-fit:cover}
.media__caption{
  position:absolute;left:0;bottom:0;right:0;z-index:2;
  padding:10px 14px;background:rgba(12,53,71,.86);color:var(--c-snow);
  font-family:var(--font-mono);font-size:11.5px;letter-spacing:.08em;
}
.media--16x9{aspect-ratio:16/9}
.media--4x3{aspect-ratio:4/3}
.media--3x2{aspect-ratio:3/2}
.media--1x1{aspect-ratio:1/1}
.media--lake{background:linear-gradient(180deg,var(--c-mist) 0 34%,var(--c-mid) 34% 62%,var(--c-deep) 62% 100%)}
.media--lake::after{
  content:"";position:absolute;left:0;right:0;top:30%;height:2px;background:var(--c-gold);
  box-shadow:0 14px 0 rgba(251,250,247,.4),0 30px 0 rgba(251,250,247,.22);
}
.media--ridge{background:linear-gradient(180deg,var(--c-snow) 0 52%,var(--c-mist) 52% 100%)}
.media--ridge::after{
  content:"";position:absolute;inset:auto 0 0 0;height:62%;background:var(--c-primary);
  clip-path:polygon(0 100%,0 52%,13% 24%,27% 56%,43% 12%,60% 50%,76% 26%,100% 62%,100% 100%);
}
.media--road{background:linear-gradient(180deg,var(--c-deep) 0%,#124054 58%,var(--c-primary) 100%)}
.media--road::after{
  content:"";position:absolute;left:50%;top:0;height:100%;width:14px;transform:translateX(-50%);
  background-image:repeating-linear-gradient(180deg,var(--c-gold) 0 22px,transparent 22px 46px);
  clip-path:polygon(36% 0,64% 0,100% 100%,0 100%);opacity:.9;
}
.media--blueprint{
  background:
    linear-gradient(90deg,rgba(62,146,172,.3) 1px,transparent 1px) 0 0/28px 28px,
    linear-gradient(180deg,rgba(62,146,172,.3) 1px,transparent 1px) 0 0/28px 28px,
    var(--c-mist);
}

/* ---------- 14. 筛选 / Tab / 复制 ---------- */
.filter-bar{display:flex;flex-wrap:wrap;align-items:center;gap:10px;margin-bottom:clamp(20px,3vw,32px)}
.filter-btn{
  padding:9px 16px;font-size:13.5px;font-weight:600;letter-spacing:.02em;
  border:2px solid var(--c-ink);background:var(--c-snow);color:var(--c-ink);
  box-shadow:3px 3px 0 rgba(12,53,71,.14);
  transition:background-color .18s ease,color .18s ease,box-shadow .18s ease,transform .18s ease;
}
.filter-btn:hover{transform:translate(-1px,-1px);box-shadow:4px 4px 0 rgba(12,53,71,.2)}
.filter-btn[aria-pressed="true"]{
  background:var(--c-primary);border-color:var(--c-deep);color:var(--c-snow);
  box-shadow:3px 3px 0 rgba(223,162,43,.55);
}
.filter-status{font-family:var(--font-mono);font-size:11.5px;letter-spacing:.1em;color:var(--c-stone)}
[data-filter-item][hidden]{display:none}

.tabs{display:flex;flex-wrap:wrap;gap:2px;border-bottom:2px solid var(--c-ink);margin-bottom:28px}
.tab{
  padding:10px 18px;font-size:14.5px;font-weight:600;color:var(--c-stone);
  background:var(--c-mist);border:2px solid var(--c-ink);border-bottom:0;margin-bottom:-2px;
  transition:background-color .18s ease,color .18s ease;
}
.tab[aria-selected="true"]{background:var(--c-snow);color:var(--c-primary);box-shadow:inset 0 4px 0 var(--c-gold)}
.tab-panel[hidden]{display:none}

.copy-btn{
  font-family:var(--font-mono);font-size:11.5px;letter-spacing:.12em;
  padding:7px 12px;border:2px solid var(--c-ink);background:var(--c-mist);color:var(--c-ink);
  transition:background-color .18s ease,border-color .18s ease;
}
.copy-btn:hover{background:var(--c-gold-lt)}
.copy-btn[data-copied="true"]{background:var(--c-gold);border-color:var(--c-ink)}

/* ---------- 15. 入场显现 ---------- */
[data-reveal]{opacity:1;transform:none}
.has-js [data-reveal]{opacity:0;transform:translateY(18px);transition:opacity .24s ease,transform .24s ease}
.has-js [data-reveal].is-visible{opacity:1;transform:none}

/* ---------- 16. 头部 ---------- */
.skip-link{
  position:absolute;left:16px;top:-120px;z-index:200;
  background:var(--c-gold);color:var(--c-ink);border:2px solid var(--c-ink);
  padding:10px 16px;font-size:14px;font-weight:600;
  transition:top .2s ease;
}
.skip-link:focus{top:12px}

.site-header{
  position:fixed;top:0;left:0;right:0;z-index:120;
  color:var(--c-ink);
  background:linear-gradient(180deg,rgba(251,250,247,.94) 0%,rgba(251,250,247,.7) 68%,rgba(251,250,247,0) 100%);
  transition:background-color .32s ease,color .32s ease,box-shadow .32s ease,background-image .32s ease;
}
.site-header[data-scrolled="true"]{
  background-color:var(--c-primary);
  background-image:none;
  color:var(--c-snow);
  box-shadow:0 12px 28px rgba(12,53,71,.22);
}
.header-inner{
  display:grid;grid-template-columns:auto 1fr auto;align-items:center;
  gap:clamp(16px,3vw,40px);
  max-width:var(--maxw);margin-inline:auto;
  padding-inline:var(--gutter);height:var(--header-h);
}

.brand{display:inline-flex;align-items:center;gap:12px;min-width:0}
.brand__mark{
  width:34px;height:34px;flex:0 0 auto;border:2px solid currentColor;
  background:linear-gradient(180deg,
    var(--c-gold) 0 24%,transparent 24% 38%,
    var(--c-mid) 38% 62%,transparent 62% 76%,
    var(--c-deep) 76% 100%);
  box-shadow:3px 3px 0 rgba(223,162,43,.45);
}
.brand__text{display:flex;flex-direction:column;min-width:0}
.brand__name{font-size:17px;font-weight:600;letter-spacing:.02em;line-height:1.15;white-space:nowrap}
.brand__ver{
  font-family:var(--font-mono);font-size:11px;letter-spacing:.14em;
  color:var(--c-stone);margin-top:3px;white-space:nowrap;
}
.site-header[data-scrolled="true"] .brand__ver{color:var(--c-gold-lt)}

.site-nav{justify-self:center}
.nav-list{display:flex;align-items:center;justify-content:center;gap:2px}
.nav-link{
  position:relative;display:inline-block;padding:9px 12px;
  font-size:14.5px;font-weight:500;letter-spacing:.02em;
  border:2px solid transparent;white-space:nowrap;
  transition:background-color .2s ease,color .2s ease,border-color .2s ease;
}
.nav-link::after{
  content:"";position:absolute;left:12px;right:12px;bottom:3px;height:3px;
  background:var(--c-gold);transform:scaleX(0);transform-origin:left;
  transition:transform .24s ease;
}
.nav-link:hover::after,.nav-link:focus-visible::after{transform:scaleX(1)}
.nav-link[aria-current="page"]{
  background:var(--c-gold);color:var(--c-ink);border-color:var(--c-ink);
  box-shadow:3px 3px 0 rgba(12,53,71,.28);
}
.nav-link[aria-current="page"]::after{transform:scaleX(0)}

.header-meta{
  display:flex;align-items:center;gap:16px;
  font-family:var(--font-mono);font-size:11.5px;letter-spacing:.12em;
}
.header-meta__time{color:var(--c-stone);white-space:nowrap}
.header-meta__time::before{
  content:"";display:inline-block;width:6px;height:6px;margin-right:8px;
  background:var(--c-gold);vertical-align:middle;
}
.site-header[data-scrolled="true"] .header-meta__time{color:var(--c-mist)}
.header-meta__link{
  color:inherit;padding-bottom:2px;border-bottom:2px solid var(--c-gold);
  transition:color .2s ease;
}
.header-meta__link:hover{color:var(--c-gold)}

.nav-toggle{
  display:none;width:44px;height:44px;flex-direction:column;
  align-items:center;justify-content:center;gap:5px;
  border:2px solid currentColor;justify-self:end;
}
.nav-toggle__bar{display:block;width:20px;height:2px;background:currentColor;transition:transform .2s ease,opacity .2s ease}
.nav-toggle[aria-expanded="true"] .nav-toggle__bar:nth-child(1){transform:translateY(7px) 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(-7px) rotate(-45deg)}

.scroll-progress{
  position:absolute;left:0;bottom:0;display:block;width:100%;height:3px;
  background:var(--c-gold);transform:scaleX(0);transform-origin:0 50%;
  opacity:0;transition:opacity .24s ease;
}
.site-header[data-scrolled="true"] .scroll-progress{opacity:1}

/* ---------- 17. 页脚 ---------- */
.site-footer{
  position:relative;margin-top:clamp(64px,10vw,140px);
  padding-top:clamp(48px,7vw,84px);
  background:var(--c-deep);color:var(--c-snow);
}
.site-footer::before{
  content:"";position:absolute;top:0;left:0;right:0;height:8px;
  background-image:repeating-linear-gradient(90deg,var(--c-gold) 0 34px,transparent 34px 68px);
}
.site-footer p{max-width:44em}
.site-footer .brand__mark{border-color:var(--c-gold-lt);box-shadow:3px 3px 0 rgba(251,250,247,.18)}

.footer-brand{
  display:flex;align-items:center;gap:18px;flex-wrap:wrap;
  padding-bottom:24px;border-bottom:2px solid rgba(223,162,43,.4);
  margin-bottom:clamp(28px,4vw,48px);
}
.footer-brand__name{font-size:19px;font-weight:600;letter-spacing:.02em}
.footer-brand__desc{font-size:13.5px;line-height:1.7;color:rgba(251,250,247,.7);margin-top:4px}
.footer-brand__ver{margin-left:auto;font-size:11.5px;letter-spacing:.16em;color:var(--c-gold-lt)}
@media (max-width:640px){.footer-brand__ver{margin-left:0}}

.footer-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:clamp(24px,3vw,48px)}
.footer-col__title{
  font-family:var(--font-mono);font-size:11.5px;font-weight:500;
  letter-spacing:.18em;color:var(--c-gold-lt);margin-bottom:18px;
}
.footer-list li{margin-bottom:10px;font-size:14.5px;line-height:1.65}
.footer-list a{color:rgba(251,250,247,.82);border-bottom:1px solid transparent;transition:color .2s ease,border-color .2s ease}
.footer-list a:hover{color:var(--c-gold);border-bottom-color:var(--c-gold)}
.footer-list--plain li{color:rgba(251,250,247,.66)}
.footer-list--plain .mono{color:rgba(251,250,247,.86)}

.footer-bottom{
  margin-top:clamp(32px,5vw,64px);padding:20px 0 28px;
  border-top:1px solid rgba(251,250,247,.16);
  display:flex;flex-wrap:wrap;align-items:center;justify-content:space-between;gap:12px 28px;
  font-size:13px;
}
.footer-legal{color:rgba(251,250,247,.66)}
.footer-legal .mono{color:rgba(251,250,247,.8)}
.footer-links{display:flex;flex-wrap:wrap;gap:20px}
.footer-links a{color:rgba(251,250,247,.82);border-bottom:1px solid transparent;transition:color .2s ease,border-color .2s ease}
.footer-links a:hover{color:var(--c-gold);border-bottom-color:var(--c-gold)}

/* ---------- 18. 响应式 ---------- */
@media (max-width:1180px){
  .header-meta__time{display:none}
  .nav-link{padding:9px 9px;font-size:14px}
}
@media (max-width:980px){
  .header-inner{grid-template-columns:1fr auto;gap:12px}
  .nav-toggle{display:inline-flex}
  .header-meta{display:none}
  .site-nav{
    position:fixed;left:16px;right:16px;top:calc(var(--header-h) + 8px);
    justify-self:stretch;
    background:var(--c-deep);border:2px solid var(--c-deep);
    box-shadow:8px 10px 0 rgba(12,53,71,.3);
    padding:12px;max-height:calc(100vh - var(--header-h) - 36px);overflow-y:auto;
    opacity:0;visibility:hidden;transform:translateY(-10px);
    transition:opacity .18s ease,transform .18s ease,visibility .18s ease;
  }
  .site-nav[data-open="true"]{opacity:1;visibility:visible;transform:translateY(0)}
  .nav-list{display:grid;gap:6px;justify-content:stretch}
  .nav-link{
    display:block;color:var(--c-snow);border-color:rgba(251,250,247,.2);
    padding:13px 14px;font-size:15.5px;
  }
  .nav-link::after{display:none}
  .nav-link[aria-current="page"]{background:var(--c-gold);color:var(--c-ink);border-color:var(--c-gold)}
  .site-footer{margin-top:clamp(48px,9vw,96px)}
  .footer-grid{grid-template-columns:repeat(2,minmax(0,1fr))}
}
@media (max-width:900px){
  .bento{grid-template-columns:repeat(6,minmax(0,1fr))}
  .cell-1x1{grid-column:span 3}
  .cell-2x1,.cell-2x2,.cell-3x2{grid-column:span 6}
}
@media (max-width:640px){
  body{font-size:16px}
  .footer-grid{grid-template-columns:1fr}
  .footer-bottom{justify-content:flex-start}
  .bento{grid-template-columns:1fr}
  .cell-1x1,.cell-2x1,.cell-2x2,.cell-3x2{grid-column:1/-1}
  .display{font-size:clamp(30px,9vw,44px)}
}

/* ---------- 19. 动效偏好 ---------- */
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{
    animation-duration:.001ms!important;
    animation-iteration-count:1!important;
    transition-duration:.001ms!important;
  }
  .has-js [data-reveal]{opacity:1;transform:none}
  .card:hover{transform:none}
  .btn:hover{transform:none}
}