/* ===========================================================
   UED 标准档案站 · 共享样式 /assets/site.css
   洁净白 + 深墨蓝 + 品牌橙 / 纸张叠层 · 印刷边框 · 编号批注
   =========================================================== */

/* ---------- 1. 设计令牌 ---------- */
:root{
  --c-white:#FFFFFF;
  --c-paper:#F5F7F8;
  --c-ink:#0E1B2A;
  --c-ink-2:#16324F;
  --c-orange:#F97316;
  --c-orange-deep:#DE6407;
  --c-orange-soft:#FDE3CC;
  --c-green:#4F7A66;
  --c-green-soft:#E4EDE8;
  --c-note:#5B6672;
  --c-amber:#B26A00;
  --c-line:#D7DEE4;
  --c-line-strong:#B9C4CE;

  --font-display:"Noto Sans SC","Source Han Sans SC","PingFang SC","Microsoft YaHei",system-ui,-apple-system,"Segoe UI",sans-serif;
  --font-body:"Inter","Noto Sans SC","PingFang SC","Microsoft YaHei",system-ui,-apple-system,"Segoe UI",sans-serif;
  --font-mono:"JetBrains Mono","IBM Plex Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,"Noto Sans Mono",monospace;

  --header-h:96px;
  --header-h-sm:64px;
  --shell-max:1280px;
  --shell-pad:clamp(20px,5vw,56px);
  --radius:2px;
  color-scheme:light;
}
@media (max-width:900px){
  :root{ --header-h:64px; --shell-pad:clamp(16px,5vw,32px); }
}

/* ---------- 2. Reset 与中文排版基础 ---------- */
*,*::before,*::after{box-sizing:border-box}
html{
  -webkit-text-size-adjust:100%;
  scroll-behavior:smooth;
  scroll-padding-top:calc(var(--header-h) + 16px);
}
body{
  margin:0;
  background:var(--c-white);
  color:var(--c-ink);
  font-family:var(--font-body);
  font-size:17px;
  font-weight:400;
  line-height:1.8;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}
h1,h2,h3,h4,h5,h6{
  margin:0;
  font-family:var(--font-display);
  font-weight:800;
  line-height:1.15;
  letter-spacing:-.02em;
  color:var(--c-ink);
  text-wrap:balance;
}
h1{font-size:clamp(36px,5vw,68px);line-height:1.06;letter-spacing:-.03em}
h2{font-size:clamp(28px,3.4vw,44px)}
h3{font-size:clamp(21px,2vw,26px);line-height:1.25}
h4{font-size:18px;line-height:1.35}
p{margin:0 0 1.15em;text-wrap:pretty}
p:last-child{margin-bottom:0}
a{color:var(--c-ink-2);text-decoration-thickness:1px;text-underline-offset:3px}
a:hover{color:var(--c-orange-deep)}
ul,ol{margin:0;padding:0}
img,picture,svg,video{max-width:100%}
img{display:block;height:auto}
button{font:inherit;color:inherit}
strong{font-weight:700}
hr{border:0;border-top:1px solid var(--c-line);margin:0}
::selection{background:var(--c-orange-soft);color:var(--c-ink)}
:focus-visible{outline:2px solid var(--c-orange);outline-offset:3px;border-radius:var(--radius)}
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
  }
}

/* ---------- 3. 布局骨架 ---------- */
.container{width:100%;max-width:var(--shell-max);margin-inline:auto;padding-inline:var(--shell-pad)}
.container--narrow{max-width:920px}
.section{padding-block:clamp(56px,8vw,104px)}
.section--tight{padding-block:clamp(40px,5vw,64px)}
.section--paper{background:var(--c-paper)}
.section--ink{background:var(--c-ink);color:rgba(255,255,255,.78)}
.section--ink h1,.section--ink h2,.section--ink h3,.section--ink h4{color:#fff}
.section--ink a{color:#fff}
.section--ink a:hover{color:var(--c-orange)}

#main-content{padding-top:var(--header-h)}
#main-content[data-header-overlay]{padding-top:0}

/* ---------- 4. 通用工具 ---------- */
.visually-hidden{
  position:absolute !important;
  width:1px;height:1px;
  padding:0;margin:-1px;
  overflow:hidden;
  clip:rect(0 0 0 0);
  clip-path:inset(50%);
  white-space:nowrap;
  border:0;
}
.mono{
  font-family:var(--font-mono);
  font-variant-numeric:tabular-nums;
  letter-spacing:.04em;
}
.divider{border:0;border-top:1px solid var(--c-line);margin-block:clamp(28px,4vw,56px)}
.prose{max-width:66ch}
.prose ul,.prose ol{padding-left:1.15em}
.prose li+li{margin-top:.4em}
.prose>*:last-child{margin-bottom:0}

/* ---------- 5. 按钮 ---------- */
.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:9px;
  padding:14px 22px;
  font-family:var(--font-body);
  font-size:16px;
  font-weight:600;
  line-height:1;
  letter-spacing:.01em;
  color:var(--c-ink);
  background:transparent;
  border:1px solid var(--c-line-strong);
  border-radius:var(--radius);
  text-decoration:none;
  cursor:pointer;
  transition:background .18s ease,color .18s ease,border-color .18s ease;
}
.btn:hover{border-color:var(--c-ink);color:var(--c-ink)}
.btn--primary{
  background:var(--c-orange);
  border-color:var(--c-orange);
  color:var(--c-ink);
}
.btn--primary:hover{
  background:var(--c-orange-deep);
  border-color:var(--c-orange-deep);
  color:var(--c-white);
}
.btn--ghost{
  background:transparent;
  border-color:var(--c-line-strong);
  color:var(--c-ink);
}
.btn--ghost:hover{background:var(--c-paper);border-color:var(--c-ink)}

/* ---------- 6. 头部 ---------- */
.site-header{
  position:fixed;
  top:0;left:0;right:0;
  z-index:100;
  color:var(--c-ink);
  background:linear-gradient(180deg,rgba(255,255,255,.95) 0%,rgba(255,255,255,.80) 58%,rgba(255,255,255,0) 100%);
  border-bottom:1px solid transparent;
  transition:background .25s ease,border-color .25s ease;
}
.site-header[data-scrolled],
.site-header[data-nav-open]{
  background:var(--c-white);
  border-bottom-color:var(--c-line);
}

.header-inner{
  position:relative;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:20px;
  width:100%;
  max-width:var(--shell-max);
  margin-inline:auto;
  padding-inline:var(--shell-pad);
  height:var(--header-h);
  transition:height .22s ease;
}
.site-header[data-scrolled] .header-inner{height:var(--header-h-sm)}

/* 品牌：四条短横线构成的标准编号符号 */
.brand{
  display:inline-flex;
  align-items:center;
  gap:12px;
  color:inherit;
  text-decoration:none;
  flex:0 0 auto;
}
.brand:hover{color:inherit}
.brand__mark{display:grid;gap:3px;width:26px;flex:0 0 auto}
.brand__mark i{display:block;height:2px;background:var(--c-orange);border-radius:0;font-style:normal}
.brand__mark i:nth-child(1){width:26px}
.brand__mark i:nth-child(2){width:17px}
.brand__mark i:nth-child(3){width:26px}
.brand__mark i:nth-child(4){width:11px}
.brand__text{display:block}
.brand__name{
  display:block;
  font-family:var(--font-display);
  font-size:22px;
  font-weight:900;
  line-height:1;
  letter-spacing:.06em;
}
.brand__tagline{
  display:block;
  margin-top:3px;
  font-family:var(--font-mono);
  font-size:11px;
  font-weight:400;
  letter-spacing:.14em;
  opacity:.62;
}

/* 导航 */
.nav{
  display:flex;
  align-items:center;
  gap:clamp(8px,1.6vw,26px);
  margin-left:auto;
}
.nav__list{
  display:flex;
  align-items:center;
  gap:clamp(4px,1.4vw,22px);
  list-style:none;
}
.nav__item{display:block}
.nav__link{
  position:relative;
  display:inline-block;
  padding:8px 2px;
  font-size:15px;
  font-weight:500;
  letter-spacing:.01em;
  color:inherit;
  text-decoration:none;
  transition:color .18s ease;
}
.nav__link::after{
  content:"";
  position:absolute;
  left:0;right:0;bottom:2px;
  height:2px;
  background:var(--c-orange);
  transform:scaleX(0);
  transform-origin:left center;
  transition:transform .22s ease;
}
.nav__link:hover::after{transform:scaleX(1)}
.nav__link[aria-current="page"]{color:var(--c-orange-deep);font-weight:600}
.nav__link[aria-current="page"]::after{transform:scaleX(1)}
.nav__foot{display:none;flex-direction:column;gap:16px;margin-top:28px}
.nav__meta{
  margin:0;
  font-family:var(--font-mono);
  font-size:12.5px;
  letter-spacing:.03em;
  color:var(--c-note);
}

/* 头部右侧动作区 */
.header-actions{display:flex;align-items:center;gap:12px;flex:0 0 auto}
.header-cta{padding:11px 18px;font-size:15px}

/* 汉堡按钮 */
.nav-toggle{
  display:none;
  align-items:center;
  justify-content:center;
  width:44px;height:44px;
  padding:0;
  color:inherit;
  background:transparent;
  border:1px solid var(--c-line-strong);
  border-radius:var(--radius);
  cursor:pointer;
}
.nav-toggle__bars{display:grid;gap:5px;width:18px}
.nav-toggle__bar{
  display:block;
  height:2px;
  background:currentColor;
  transition:transform .22s ease,opacity .22s ease;
}
.site-header[data-nav-open] .nav-toggle__bar:nth-child(1){transform:translateY(3.5px) rotate(45deg)}
.site-header[data-nav-open] .nav-toggle__bar:nth-child(2){transform:translateY(-3.5px) rotate(-45deg)}

/* 滚动进度条 */
.scroll-progress{
  position:absolute;
  left:0;right:0;bottom:0;
  height:2px;
  background:var(--c-orange);
  transform:scaleX(0);
  transform-origin:left center;
  pointer-events:none;
  will-change:transform;
}

/* 跳转链接 */
.skip-link{
  position:fixed;
  top:10px;left:10px;
  z-index:300;
  padding:12px 20px;
  font-size:15px;
  font-weight:600;
  color:var(--c-white);
  background:var(--c-ink);
  border:1px solid var(--c-ink);
  border-radius:var(--radius);
  text-decoration:none;
  transform:translateY(-220%);
}
.skip-link:focus,.skip-link:focus-visible{transform:none;color:var(--c-white)}

/* ---------- 7. 页脚 ---------- */
.site-footer{
  background:var(--c-ink);
  color:rgba(255,255,255,.72);
  font-size:15px;
}
.footer-inner{
  width:100%;
  max-width:var(--shell-max);
  margin-inline:auto;
  padding:clamp(48px,7vw,92px) var(--shell-pad) 28px;
}
.footer-grid{
  display:grid;
  grid-template-columns:minmax(0,1.7fr) repeat(3,minmax(0,1fr));
  gap:clamp(28px,4vw,56px);
}
.brand--footer{color:var(--c-white)}
.brand--footer .brand__tagline{color:rgba(255,255,255,.6);opacity:1}
.brand--footer:hover{color:var(--c-white)}
.footer-brand__note{
  margin:16px 0 0;
  max-width:34ch;
  font-size:14px;
  line-height:1.75;
  color:rgba(255,255,255,.58);
}
.footer-col__title{
  margin:0 0 16px;
  font-family:var(--font-mono);
  font-size:12px;
  font-weight:500;
  letter-spacing:.14em;
  text-transform:uppercase;
  color:var(--c-orange);
}
.footer-list{list-style:none;display:grid;gap:11px}
.footer-link{
  color:rgba(255,255,255,.8);
  font-size:15px;
  text-decoration:none;
  transition:color .18s ease;
}
.footer-link:hover{
  color:var(--c-white);
  text-decoration:underline;
  text-underline-offset:3px;
  text-decoration-color:var(--c-orange);
}
.footer-contact{
  display:grid;
  grid-template-columns:repeat(auto-fit,minmax(210px,1fr));
  gap:clamp(18px,3vw,40px);
  margin-top:clamp(36px,5vw,64px);
  padding-top:clamp(24px,3vw,36px);
  border-top:1px solid rgba(255,255,255,.14);
}
.footer-contact__label{
  display:block;
  margin-bottom:7px;
  font-family:var(--font-mono);
  font-size:11.5px;
  letter-spacing:.14em;
  color:rgba(255,255,255,.45);
}
.footer-contact__value{
  margin:0;
  font-size:15.5px;
  line-height:1.6;
  color:var(--c-white);
}
.footer-contact__value--mono{
  font-family:var(--font-mono);
  font-variant-numeric:tabular-nums;
  letter-spacing:.03em;
}
.footer-contact__hint{
  margin:6px 0 0;
  font-size:13px;
  color:rgba(255,255,255,.5);
}
.footer-bottom{
  display:flex;
  flex-wrap:wrap;
  align-items:baseline;
  justify-content:space-between;
  gap:10px 28px;
  margin-top:clamp(28px,4vw,44px);
  padding-top:20px;
  border-top:1px solid rgba(255,255,255,.14);
}
.footer-legal{
  margin:0;
  font-family:var(--font-mono);
  font-size:12.5px;
  letter-spacing:.05em;
  color:rgba(255,255,255,.55);
}
.footer-meta{
  margin:0;
  font-size:13px;
  color:rgba(255,255,255,.5);
}

/* ---------- 8. 章节体系 ---------- */
.section-head{
  display:grid;
  gap:14px;
  max-width:900px;
  margin-bottom:clamp(28px,4vw,48px);
}
.section-kicker{
  margin:0;
  font-family:var(--font-mono);
  font-size:13px;
  letter-spacing:.14em;
  text-transform:uppercase;
  color:var(--c-note);
}
.section-num{
  display:block;
  font-family:var(--font-mono);
  font-size:clamp(34px,4.6vw,60px);
  font-weight:700;
  line-height:1;
  letter-spacing:.01em;
  color:var(--c-ink-2);
}
.section-num::before{content:"[";color:var(--c-orange)}
.section-num::after{content:"]";color:var(--c-orange)}
.section-title{font-size:clamp(24px,2.9vw,38px);letter-spacing:-.025em}
.section-lead{
  margin:0;
  max-width:62ch;
  font-size:clamp(17px,1.3vw,19px);
  color:var(--c-note);
}

/* ---------- 9. 网格工具 ---------- */
.grid{display:grid;gap:clamp(20px,3vw,40px)}
.grid--2{grid-template-columns:repeat(2,minmax(0,1fr))}
.grid--3{grid-template-columns:repeat(3,minmax(0,1fr))}
.grid--4{grid-template-columns:repeat(4,minmax(0,1fr))}
.grid--12{grid-template-columns:repeat(12,minmax(0,1fr))}
.col-3{grid-column:span 3}
.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}

/* ---------- 10. 状态与批注组件 ---------- */
.tag{
  display:inline-flex;
  align-items:center;
  gap:6px;
  padding:4px 9px;
  font-family:var(--font-mono);
  font-size:12.5px;
  letter-spacing:.06em;
  color:var(--c-note);
  background:var(--c-white);
  border:1px solid var(--c-line);
  border-radius:var(--radius);
}
.tag--ok{color:var(--c-green);background:var(--c-green-soft);border-color:transparent}
.tag--review{color:var(--c-amber);background:var(--c-orange-soft);border-color:transparent}
.tag--wait{
  color:var(--c-note);
  background:repeating-linear-gradient(135deg,var(--c-white) 0 5px,var(--c-paper) 5px 10px);
  border-color:var(--c-line);
}
.status-dot{
  display:inline-block;
  width:9px;height:9px;
  border-radius:50%;
  background:var(--c-note);
  vertical-align:middle;
}
.status-dot--ok{background:var(--c-green)}
.status-dot--review{background:transparent;border:1.5px solid var(--c-amber)}
.status-dot--pending{
  background:repeating-linear-gradient(135deg,var(--c-note) 0 2px,transparent 2px 4px);
}
.note{
  margin:0;
  padding-left:12px;
  border-left:2px solid var(--c-orange);
  font-family:var(--font-mono);
  font-size:13px;
  line-height:1.7;
  color:var(--c-note);
}

/* ---------- 11. 纸张叠层容器与仪表板 ---------- */
.panel{
  position:relative;
  padding:clamp(20px,3vw,32px);
  background:var(--c-white);
  border:1px solid var(--c-line);
  border-radius:var(--radius);
  box-shadow:8px 8px 0 var(--c-paper),8px 8px 0 1px var(--c-line);
}
.panel--paper{background:var(--c-paper)}
.metric{
  display:flex;
  flex-direction:column;
  gap:6px;
  padding-left:14px;
  border-left:2px solid var(--c-orange);
}
.metric__num{
  font-family:var(--font-mono);
  font-size:clamp(26px,3vw,38px);
  font-weight:700;
  line-height:1;
  letter-spacing:-.02em;
  color:var(--c-ink);
}
.metric__label{font-size:14px;line-height:1.6;color:var(--c-note)}

/* ---------- 12. 图片容器基础（页面阶段放置占位图） ---------- */
.media-frame{
  position:relative;
  display:block;
  width:100%;
  aspect-ratio:4/3;
  overflow:hidden;
  background:var(--c-paper);
  border:1px solid var(--c-line);
  border-radius:var(--radius);
  box-shadow:6px 6px 0 var(--c-paper),6px 6px 0 1px var(--c-line);
}
.media-frame img,
.media-frame picture,
.media-frame picture>img,
.media-frame svg{
  display:block;
  width:100%;
  height:100%;
  object-fit:cover;
}
.media-frame img{filter:saturate(.94) contrast(1.02)}
.media-frame--wide{aspect-ratio:16/9}
.media-frame--tall{aspect-ratio:3/4}
.media-frame--square{aspect-ratio:1/1}
.media-frame--plain{box-shadow:none}
.media-frame__caption{
  display:block;
  margin-top:10px;
  font-family:var(--font-mono);
  font-size:12.5px;
  letter-spacing:.04em;
  color:var(--c-note);
}

/* ---------- 13. 面包屑 ---------- */
.breadcrumbs{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:8px;
  margin:0;
  padding:0;
  list-style:none;
  font-family:var(--font-mono);
  font-size:13px;
  color:var(--c-note);
}
.breadcrumbs__item{display:inline-flex;align-items:center;gap:8px}
.breadcrumbs__sep{color:var(--c-line-strong)}
.breadcrumbs a{color:var(--c-note);text-decoration:none}
.breadcrumbs a:hover{color:var(--c-orange-deep);text-decoration:underline;text-underline-offset:3px}

/* ---------- 14. 章节目录与返回顶部 ---------- */
.toc{position:sticky;top:calc(var(--header-h) + 28px)}
.toc__list{list-style:none;border-left:1px solid var(--c-line)}
.toc__link{
  display:block;
  margin-left:-1px;
  padding:7px 0 7px 14px;
  font-size:14px;
  line-height:1.6;
  color:var(--c-note);
  text-decoration:none;
  border-left:2px solid transparent;
  transition:color .18s ease,border-color .18s ease;
}
.toc__link:hover{color:var(--c-ink)}
.toc__link[aria-current="true"]{
  color:var(--c-ink);
  font-weight:600;
  border-left-color:var(--c-orange);
}
.to-top{
  position:fixed;
  right:clamp(16px,3vw,36px);
  bottom:clamp(16px,3vw,36px);
  z-index:90;
  display:inline-flex;
  align-items:center;
  justify-content:center;
  width:46px;height:46px;
  padding:0;
  color:var(--c-ink);
  background:var(--c-white);
  border:1px solid var(--c-line-strong);
  border-radius:var(--radius);
  cursor:pointer;
  opacity:0;
  visibility:hidden;
  transform:translateY(8px);
  transition:opacity .22s ease,transform .22s ease,visibility .22s,border-color .18s ease;
}
.to-top[data-visible]{opacity:1;visibility:visible;transform:none}
.to-top:hover{border-color:var(--c-orange);color:var(--c-orange-deep)}

/* ---------- 15. 滚动显现 ---------- */
[data-reveal]{
  opacity:0;
  transform:translateY(14px);
  transition:opacity .6s ease,transform .6s ease;
}
[data-reveal][data-shown]{opacity:1;transform:none}
@media (prefers-reduced-motion:reduce){
  [data-reveal]{opacity:1;transform:none;transition:none}
}

/* ---------- 16. 响应式 ---------- */
@media (max-width:1080px){
  .header-cta{display:none}
}
@media (max-width:980px){
  .footer-grid{grid-template-columns:repeat(2,minmax(0,1fr))}
  .footer-brand{grid-column:1 / -1}
}
@media (max-width:900px){
  .nav{
    position:fixed;
    left:0;right:0;
    top:var(--header-h);
    bottom:0;
    z-index:99;
    display:flex;
    flex-direction:column;
    align-items:stretch;
    gap:0;
    margin-left:0;
    padding:24px var(--shell-pad) 40px;
    overflow-y:auto;
    color:var(--c-ink);
    background:var(--c-white);
    border-top:1px solid var(--c-line);
    opacity:0;
    visibility:hidden;
    transform:translateY(-10px);
    transition:opacity .22s ease,transform .22s ease,visibility .22s;
  }
  .nav[data-open]{opacity:1;visibility:visible;transform:none}
  .nav__list{flex-direction:column;align-items:stretch;gap:0}
  .nav__item{border-bottom:1px solid var(--c-line)}
  .nav__link{display:flex;justify-content:space-between;padding:16px 0;font-size:19px;font-weight:600}
  .nav__link::after{display:none}
  .nav__foot{display:flex}
  .nav-toggle{display:inline-flex}
  .header-actions{gap:8px}
}
@media (max-width:900px){
  .grid--3,.grid--4{grid-template-columns:repeat(2,minmax(0,1fr))}
  .col-3,.col-4,.col-5,.col-6,.col-7,.col-8{grid-column:span 12}
}
@media (max-width:620px){
  body{font-size:16.5px}
  .brand__tagline{display:none}
  .grid--2,.grid--3,.grid--4{grid-template-columns:minmax(0,1fr)}
  .footer-grid{grid-template-columns:minmax(0,1fr)}
  .footer-bottom{flex-direction:column;align-items:flex-start}
}