/* ===== 1. 变量 ===== */
:root{
  --ink:#0A1A2A;
  --ink-2:#0F2438;
  --paper:#F6F4EF;
  --black:#07090C;
  --copper:#C08A3E;
  --copper-soft:#E3C58C;
  --copper-deep:#8A5F22;
  --silver:#C7CED6;
  --silver-soft:#E9EDF0;
  --celadon:#6F9B8D;
  --celadon-dark:#4F756A;
  --muted-dark:#B9C4CE;
  --muted-light:#3C4C59;
  --rail-w:clamp(264px,19vw,316px);
  --radius-lg:28px;
  --radius-md:18px;
  --radius-sm:10px;
  --radius-pill:999px;
  --font-display:"PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,-apple-system,sans-serif;
  --font-sans:"PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,-apple-system,"Segoe UI",sans-serif;
  --font-body:"Songti SC","Source Han Serif SC","Noto Serif SC","STSong",Georgia,serif;
  --font-mono:"SFMono-Regular","JetBrains Mono","Roboto Mono",Menlo,Consolas,"Courier New",monospace;
  --ease:cubic-bezier(.22,.61,.36,1);
}

/* ===== 2. reset ===== */
*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth;scroll-padding-top:96px}
body{
  margin:0;
  background:var(--ink);
  color:var(--paper);
  font-family:var(--font-sans);
  font-size:17px;
  line-height:1.8;
  letter-spacing:.01em;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}
h1,h2,h3,h4,h5,h6,p,figure,blockquote{margin:0}
ul,ol{margin:0;padding:0;list-style:none}
img,svg,video{display:block;max-width:100%;height:auto}
button{font:inherit;color:inherit}
a{color:inherit;text-decoration:none}
::selection{background:var(--copper);color:var(--ink)}
:focus-visible{outline:2px solid var(--copper);outline-offset:3px;border-radius:4px}
.section--copper :focus-visible{outline-color:var(--ink)}

/* ===== 3. 排版 ===== */
.mono{font-family:var(--font-mono);font-variant-numeric:tabular-nums;font-feature-settings:"tnum" 1}
.display{font-family:var(--font-display);font-size:clamp(46px,7.6vw,96px);font-weight:200;line-height:.98;letter-spacing:-.02em}
.title-1{font-family:var(--font-display);font-size:clamp(32px,4.2vw,56px);font-weight:700;line-height:1.12;letter-spacing:-.01em}
.title-2{font-family:var(--font-display);font-size:clamp(22px,2.3vw,30px);font-weight:700;line-height:1.3}
.eyebrow{display:inline-block;font-family:var(--font-mono);font-size:12px;letter-spacing:.2em;text-transform:uppercase;color:var(--copper)}
.index-num{font-family:var(--font-mono);font-size:12px;letter-spacing:.16em;color:var(--copper)}
.lede{font-size:clamp(17px,1.2vw,20px);line-height:1.8;max-width:46ch;color:var(--muted-dark)}
.section--paper .lede,.section--silver .lede{color:var(--muted-light)}
.section--copper .lede{color:rgba(10,26,42,.8)}
.section--copper .eyebrow,.section--copper .index-num{color:var(--black)}
.prose{font-family:var(--font-body);font-size:17px;line-height:1.9;letter-spacing:.01em;max-width:44ch}
.prose p+p{margin-top:1em}
.prose ul{list-style:disc;padding-left:1.2em}
.prose a{color:var(--copper-soft);text-decoration:underline;text-underline-offset:3px}
.section--paper .prose a,.section--silver .prose a{color:var(--copper-deep)}
.rule{border:0;height:1px;background:currentColor;opacity:.14;margin:0}

/* ===== 4. 骨架与分区 ===== */
.canvas{width:100%;max-width:1320px;margin:0 auto;padding-inline:clamp(20px,4vw,64px)}
.section{position:relative;padding-block:clamp(52px,7vw,116px)}
.section--ink{background:var(--ink);color:var(--paper)}
.section--ink-2{background:var(--ink-2);color:var(--paper)}
.section--paper{background:var(--paper);color:var(--ink)}
.section--silver{background:var(--silver-soft);color:var(--ink)}
.section--copper{background:var(--copper);color:var(--ink)}
.auto-grid{display:grid;gap:clamp(16px,1.6vw,24px);grid-template-columns:repeat(auto-fit,minmax(260px,1fr))}

/* ===== 5. 按钮 / 标签 / 链接 ===== */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:10px;
  padding:13px 26px;border-radius:var(--radius-pill);border:1px solid transparent;
  font-family:var(--font-sans);font-size:15px;font-weight:600;letter-spacing:.02em;
  text-decoration:none;cursor:pointer;
  transition:background-color .25s var(--ease),color .25s var(--ease),border-color .25s var(--ease),transform .25s var(--ease);
}
.btn--copper{background:var(--copper);color:var(--ink)}
.btn--copper:hover{background:var(--copper-soft)}
.btn--paper{background:var(--paper);color:var(--ink)}
.btn--paper:hover{background:#fff}
.btn--ghost{background:transparent;border-color:rgba(199,206,214,.4);color:inherit}
.btn--ghost:hover{border-color:var(--copper);color:var(--copper)}
.section--paper .btn--ghost,.section--silver .btn--ghost{border-color:rgba(10,26,42,.24)}
.section--paper .btn--ghost:hover,.section--silver .btn--ghost:hover{color:var(--copper-deep);border-color:var(--copper-deep)}
.btn:hover{transform:translateY(-2px)}
.tag{display:inline-flex;align-items:center;gap:7px;padding:5px 13px;border:1px solid rgba(199,206,214,.4);border-radius:var(--radius-pill);font-family:var(--font-mono);font-size:12px;letter-spacing:.1em;color:inherit}
.section--paper .tag,.section--silver .tag{border-color:rgba(10,26,42,.22)}
.tag--copper{background:var(--copper);border-color:var(--copper);color:var(--ink)}
.tag--celadon{border-color:var(--celadon);color:var(--celadon-dark)}
.tag--celadon::before{content:"";width:6px;height:6px;border-radius:50%;background:var(--celadon)}
.section--ink .tag--celadon,.section--ink-2 .tag--celadon{color:#8FB9AB}
.link-underline{position:relative;display:inline-block;color:inherit}
.link-underline::after{content:"";position:absolute;left:0;bottom:-2px;width:100%;height:1px;background:currentColor;transform:scaleX(0);transform-origin:left;transition:transform .3s var(--ease)}
.link-underline:hover::after,.link-underline:focus-visible::after{transform:scaleX(1)}

/* ===== 6. 卡片 / Bento / 图片容器 ===== */
.card{background:var(--paper);color:var(--ink);border:1px solid rgba(10,26,42,.08);border-radius:var(--radius-lg);padding:clamp(20px,2vw,32px);transition:transform .25s var(--ease),border-color .25s var(--ease)}
.card:hover{transform:translateY(-3px);border-color:var(--copper)}
.card--ink{background:var(--ink-2);color:var(--paper);border-color:rgba(199,206,214,.16)}
.card--ink:hover{border-color:var(--copper)}
.bento{display:grid;grid-template-columns:repeat(12,1fr);gap:clamp(14px,1.4vw,22px)}
.bento__cell{grid-column:span 12;background:var(--silver-soft);color:var(--ink);border:1px solid rgba(10,26,42,.08);border-radius:var(--radius-lg);padding:clamp(20px,2.2vw,34px);transition:transform .25s var(--ease),border-color .25s var(--ease)}
.bento__cell:hover{transform:translateY(-3px);border-color:var(--copper)}
.bento__cell--ink{background:var(--ink-2);color:var(--paper);border-color:rgba(199,206,214,.16)}
.bento__cell--paper{background:var(--paper);color:var(--ink)}
.bento__cell--copper{background:var(--copper);color:var(--ink);border-color:var(--copper)}
.bento__cell--celadon{background:rgba(111,155,141,.14);border-color:rgba(111,155,141,.4)}
@media (min-width:900px){
  .bento__cell--half{grid-column:span 6}
  .bento__cell--third{grid-column:span 4}
  .bento__cell--wide{grid-column:span 8}
  .bento__cell--focus{grid-column:span 7}
  .bento__cell--tall{grid-row:span 2}
}
.media{position:relative;display:block;overflow:hidden;border-radius:var(--radius-lg);aspect-ratio:4/3;background:linear-gradient(158deg,#16293D 0%,#0A1A2A 100%)}
.media__img{width:100%;height:100%;object-fit:cover;filter:saturate(.86) contrast(1.03)}
.media__caption{margin-top:10px;font-family:var(--font-mono);font-size:12px;letter-spacing:.08em;color:var(--muted-dark)}
.section--paper .media__caption,.section--silver .media__caption{color:var(--muted-light)}
.media--16x9{aspect-ratio:16/9}
.media--3x4{aspect-ratio:3/4}
.media--1x1{aspect-ratio:1/1}

/* ===== 7. 面包屑 ===== */
.breadcrumbs{font-family:var(--font-mono);font-size:12px;letter-spacing:.06em}
.breadcrumbs__list{display:flex;flex-wrap:wrap;align-items:center;gap:10px}
.breadcrumbs__item{display:inline-flex;align-items:center;gap:10px}
.breadcrumbs__item+.breadcrumbs__item::before{content:"/";opacity:.4}
.breadcrumbs__link{color:inherit;opacity:.72;transition:opacity .25s var(--ease),color .25s var(--ease)}
.breadcrumbs__link:hover{opacity:1;color:var(--copper)}
.breadcrumbs__current{color:var(--copper)}

/* ===== 8. 跳转链接 ===== */
.skip-link{
  position:fixed;top:0;left:50%;z-index:200;
  transform:translate(-50%,-140%);
  padding:12px 24px;border-radius:0 0 var(--radius-md) var(--radius-md);
  background:var(--copper);color:var(--ink);
  font-size:14px;font-weight:600;text-decoration:none;
  transition:transform .22s var(--ease);
}
.skip-link:focus{transform:translate(-50%,0)}

/* ===== 9. 头部：侧边轨道 ===== */
.site-header{
  position:fixed;inset:0 auto 0 0;width:var(--rail-w);z-index:60;
  background:linear-gradient(180deg,var(--ink) 0%,var(--ink-2) 100%);
  border-right:1px solid rgba(199,206,214,.14);
  color:var(--paper);
}
.site-header::after{content:"";position:absolute;top:0;right:-1px;width:1px;height:96px;background:var(--copper)}
.site-header__inner{display:flex;flex-direction:column;height:100%;gap:26px;padding:30px 26px 26px;overflow-y:auto}
.brand-block{padding-bottom:22px;border-bottom:1px solid rgba(199,206,214,.14)}
.brand{display:flex;flex-direction:column;gap:8px}
.brand__mark{font-family:var(--font-display);font-size:26px;font-weight:800;letter-spacing:.12em;line-height:1}
.brand__descriptor{font-size:11px;letter-spacing:.16em;color:var(--copper-soft)}
.site-nav{display:flex;flex-direction:column;flex:1 1 auto;gap:22px;min-height:0}
.site-nav__eyebrow{font-size:11px;letter-spacing:.22em;color:rgba(199,206,214,.55)}
.nav-list{display:flex;flex-direction:column}
.nav-list__item{border-top:1px solid rgba(199,206,214,.12)}
.nav-list__item:last-child{border-bottom:1px solid rgba(199,206,214,.12)}
.nav-link{
  position:relative;display:flex;align-items:baseline;gap:14px;
  padding:13px 12px 13px 17px;border-radius:var(--radius-pill);
  color:var(--muted-dark);
  transition:color .25s var(--ease),background-color .25s var(--ease),padding-left .25s var(--ease);
}
.nav-link::before{
  content:"";position:absolute;left:2px;top:50%;width:3px;height:0;
  background:var(--copper);border-radius:3px;transform:translateY(-50%);
  transition:height .25s var(--ease);
}
.nav-link:hover{color:var(--paper);background:rgba(192,138,62,.12);padding-left:22px}
.nav-link:hover::before{height:58%}
.nav-link__index{font-size:11px;letter-spacing:.16em;color:rgba(192,138,62,.78)}
.nav-link__label{font-size:15px;font-weight:500;letter-spacing:.02em}
.nav-link[aria-current="page"]{color:var(--paper);background:rgba(192,138,62,.18);padding-left:22px}
.nav-link[aria-current="page"]::before{height:70%}
.nav-link[aria-current="page"] .nav-link__index{color:var(--copper-soft)}
.nav-utility{margin-top:auto;padding-top:20px;border-top:1px solid rgba(199,206,214,.14)}
.nav-utility__title{font-size:11px;letter-spacing:.22em;color:rgba(199,206,214,.55);margin-bottom:12px}
.utility-list{display:flex;flex-wrap:wrap;gap:8px}
.utility-link{
  display:inline-block;padding:7px 13px;border-radius:var(--radius-pill);
  border:1px solid rgba(199,206,214,.28);color:var(--silver);
  font-size:12.5px;letter-spacing:.02em;
  transition:border-color .25s var(--ease),color .25s var(--ease),background-color .25s var(--ease);
}
.utility-link:hover{border-color:var(--copper);color:var(--copper-soft);background:rgba(192,138,62,.14)}
.nav-meta{font-size:10px;letter-spacing:.22em;color:rgba(199,206,214,.45)}
.nav-toggle{
  display:none;align-items:center;gap:10px;
  padding:9px 16px;border:1px solid rgba(199,206,214,.32);border-radius:var(--radius-pill);
  background:transparent;color:var(--paper);font-size:13px;letter-spacing:.08em;cursor:pointer;
  transition:border-color .25s var(--ease),background-color .25s var(--ease);
}
.nav-toggle:hover{border-color:var(--copper);background:rgba(192,138,62,.14)}
.nav-toggle__bars{display:inline-flex;flex-direction:column;gap:4px;width:16px}
.nav-toggle__bars span{display:block;height:1.5px;border-radius:2px;background:currentColor;transition:transform .25s var(--ease),opacity .25s var(--ease)}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(1){transform:translateY(5.5px) rotate(45deg)}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(2){opacity:0}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars span:nth-child(3){transform:translateY(-5.5px) rotate(-45deg)}

/* ===== 10. 阅读进度 ===== */
.scroll-progress{position:fixed;left:0;bottom:0;width:var(--rail-w);height:3px;background:rgba(192,138,62,.18);z-index:70}
.scroll-progress__bar{display:block;height:100%;width:0;background:var(--copper)}

/* ===== 11. 页脚 ===== */
.site-footer{background:var(--ink-2);color:var(--paper);padding-top:clamp(48px,6vw,96px)}
.site-footer__inner{
  width:100%;max-width:1320px;margin:0 auto;
  padding:0 clamp(20px,4vw,64px) clamp(40px,5vw,72px);
  display:grid;gap:clamp(28px,3vw,56px);grid-template-columns:1fr;
}
.footer-brand__mark{font-family:var(--font-display);font-size:clamp(24px,2.4vw,30px);font-weight:800;letter-spacing:.14em;line-height:1.2}
.footer-brand__descriptor{margin-top:10px;font-size:11px;letter-spacing:.2em;color:var(--copper-soft)}
.footer-brand__note{margin-top:18px;max-width:34ch;font-size:14px;line-height:1.8;color:var(--muted-dark)}
.footer-nav{display:grid;gap:clamp(22px,2.4vw,40px);grid-template-columns:repeat(auto-fit,minmax(140px,1fr))}
.footer-col__title{font-size:11px;letter-spacing:.22em;color:var(--copper-soft);margin-bottom:14px}
.footer-links{display:flex;flex-direction:column;gap:10px}
.footer-link{position:relative;display:inline-block;font-size:14.5px;color:var(--silver);transition:color .25s var(--ease)}
.footer-link::after{content:"";position:absolute;left:0;bottom:-3px;width:100%;height:1px;background:currentColor;transform:scaleX(0);transform-origin:left;transition:transform .3s var(--ease)}
.footer-link:hover{color:var(--copper-soft)}
.footer-link:hover::after{transform:scaleX(1)}
.footer-contact__title{font-size:11px;letter-spacing:.22em;color:var(--copper-soft);margin-bottom:14px}
.footer-contact__list{display:flex;flex-direction:column;gap:12px}
.footer-contact__item{display:flex;gap:10px;font-size:14px;line-height:1.75;color:var(--silver)}
.footer-contact__key{flex:0 0 auto;min-width:38px;font-size:11px;letter-spacing:.14em;color:rgba(199,206,214,.55);padding-top:3px}
.footer-base{
  width:100%;max-width:1320px;margin:0 auto;
  padding:20px clamp(20px,4vw,64px) 30px;
  border-top:1px solid rgba(199,206,214,.16);
  display:flex;flex-wrap:wrap;gap:10px 24px;justify-content:space-between;align-items:center;
  font-family:var(--font-mono);font-size:12.5px;letter-spacing:.08em;color:#9FADB9;
}
.footer-base__item{margin:0}

/* ===== 12. 显现 ===== */
[data-reveal]{opacity:1;transform:none}
.js [data-reveal]{opacity:0;transform:translateY(14px);transition:opacity .5s var(--ease),transform .5s var(--ease)}
.js [data-reveal].is-visible{opacity:1;transform:none}

/* ===== 13. 桌面外壳 ===== */
@media (min-width:1024px){
  body{padding-left:var(--rail-w)}
}

/* ===== 14. 移动与平板：顶栏 + 抽屉 ===== */
@media (max-width:1023px){
  html{scroll-padding-top:88px}
  .scroll-progress{width:100%}
  .site-header{position:sticky;inset:auto;top:0;width:100%;border-right:0;border-bottom:1px solid rgba(199,206,214,.14)}
  .site-header::after{top:auto;bottom:-1px;right:auto;left:0;width:72px;height:1px}
  .site-header__inner{flex-direction:row;flex-wrap:wrap;align-items:center;gap:12px;height:auto;padding:14px 20px;overflow:visible}
  .brand-block{margin-right:auto;padding:0;border:0}
  .brand{flex-direction:row;align-items:baseline;gap:10px}
  .brand__mark{font-size:20px}
  .brand__descriptor{font-size:10px;letter-spacing:.12em}
  .nav-toggle{display:inline-flex}
  .site-nav{display:none;flex:1 1 100%;width:100%;gap:18px;margin-top:4px;padding-top:18px;border-top:1px solid rgba(199,206,214,.14)}
  .site-nav[data-open]{display:flex}
  .nav-list__item:first-child{border-top:0}
  .nav-utility{margin-top:4px}
  .nav-utility__title{margin-bottom:10px}
  .nav-meta{margin-top:2px}
}
@media (min-width:760px) and (max-width:1023px){
  .site-footer__inner{grid-template-columns:repeat(2,1fr)}
}
@media (min-width:1100px){
  .site-footer__inner{grid-template-columns:1.3fr 2fr 1.1fr}
}

/* ===== 15. 无障碍与降级 ===== */
@media (prefers-reduced-motion:reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{animation-duration:.001ms !important;animation-iteration-count:1 !important;transition-duration:.001ms !important}
  .js [data-reveal]{opacity:1;transform:none}
  .card:hover,.bento__cell:hover,.btn:hover{transform:none}
  .link-underline::after,.footer-link::after{transform:scaleX(1);opacity:.35}
}