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

/* ===== 2. 设计变量 ===== */
:root{
  --ink-900:#0D1B2A;
  --ink-700:#16293D;
  --ink-500:#2A4560;
  --mist:#7C8FA3;
  --copper:#B87A3C;
  --copper-light:#E0B57F;
  --celadon:#5F8F7E;
  --signal:#E4572E;
  --paper:#F6F2E9;
  --grid:#DCD6C8;
  --white:#FFFFFF;
  --text:#4A5560;
  --rail-w:236px;
  --topbar-h:59px;
  --gutter:clamp(18px,4vw,54px);
  --gap:clamp(14px,1.6vw,22px);
  --shell-max:1240px;
  --font-display:"Source Han Sans SC","Noto Sans SC","PingFang SC","Microsoft YaHei",system-ui,sans-serif;
  --font-serif:"Source Han Serif SC","Noto Serif SC","Songti SC",Georgia,"Times New Roman",serif;
  --font-body:"PingFang SC","Microsoft YaHei","Noto Sans SC",system-ui,-apple-system,sans-serif;
  --font-mono:"JetBrains Mono","IBM Plex Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;
  --ease:.16s cubic-bezier(.2,.7,.3,1);
}

/* ===== 3. 基础排版 ===== */
body{
  background:var(--paper);
  color:var(--text);
  font-family:var(--font-body);
  font-size:16px;
  line-height:1.75;
  letter-spacing:.01em;
  min-height:100vh;
  padding-top:var(--topbar-h);
  overflow-x:hidden;
  -webkit-font-smoothing:antialiased;
}
html.nav-open{overflow:hidden}
#main-content{scroll-margin-top:calc(var(--topbar-h) + 12px)}
h1,h2,h3,h4{font-family:var(--font-display);font-weight:600;color:var(--ink-900);line-height:1.26;letter-spacing:-.01em}
p{max-width:74ch}
strong{font-weight:600;color:var(--ink-900)}
::selection{background:var(--copper-light);color:var(--ink-900)}

:focus-visible{outline:2px solid var(--signal);outline-offset:2px}
.rail :focus-visible,.site-footer :focus-visible{outline:2px solid var(--copper-light);outline-offset:2px}

/* ===== 4. 布局工具 ===== */
.shell{width:100%;max-width:var(--shell-max);margin:0 auto;padding:0 var(--gutter)}
.section{padding:clamp(40px,6vw,84px) 0}
.stack{display:flex;flex-direction:column;gap:var(--gap)}
.grid-bento{display:grid;grid-template-columns:repeat(12,1fr);gap:var(--gap)}
.grid-bento>*{grid-column:span 12;min-width:0}
@media (max-width:767px){
  .grid-bento{grid-template-columns:repeat(4,1fr)}
}
@media (min-width:768px){
  .span-3{grid-column:span 3}
  .span-4{grid-column:span 4}
  .span-5{grid-column:span 5}
  .span-6{grid-column:span 6}
  .span-7{grid-column:span 7}
  .span-8{grid-column:span 8}
  .span-12{grid-column:span 12}
}

/* ===== 5. 跳转链接与进度条 ===== */
.skip-link{
  position:fixed;top:10px;left:10px;z-index:120;
  background:var(--copper);color:#fff;
  font-family:var(--font-display);font-size:14px;font-weight:600;
  padding:10px 16px;
  transform:translateY(-180%);
  transition:transform var(--ease);
}
.skip-link:focus{transform:translateY(0)}
.read-progress{
  position:fixed;top:0;left:0;right:0;height:3px;z-index:90;
  background:rgba(13,27,42,.08);pointer-events:none;
}
.read-progress__bar{
  display:block;height:100%;width:100%;
  background:linear-gradient(90deg,var(--copper),var(--signal));
  transform:scaleX(0);transform-origin:0 50%;
  transition:transform .12s linear;
}

/* ===== 6. 页头外壳 ===== */
.site-header{position:relative;z-index:70}

/* 移动顶栏 */
.mobile-bar{
  position:fixed;top:3px;left:0;right:0;height:calc(var(--topbar-h) - 3px);z-index:80;
  display:flex;align-items:center;justify-content:space-between;gap:12px;
  padding:0 16px;
  background:var(--ink-900);
  border-bottom:1px solid rgba(246,242,233,.14);
}
.mobile-bar__brand{display:flex;align-items:baseline;gap:8px;min-width:0}
.mobile-bar__mark{font-family:var(--font-display);font-weight:700;font-size:16px;color:var(--paper);white-space:nowrap}
.mobile-bar__sub{font-size:11px;letter-spacing:.08em;color:var(--copper-light);white-space:nowrap}
.nav-toggle{
  display:inline-flex;align-items:center;gap:8px;
  padding:7px 10px;
  border:1px solid rgba(246,242,233,.34);
  color:var(--paper);
  font-family:var(--font-mono);font-size:11.5px;letter-spacing:.12em;
  transition:border-color var(--ease),color var(--ease);
}
.nav-toggle:hover{border-color:var(--copper-light);color:var(--copper-light)}
.nav-toggle__bars{position:relative;display:block;width:16px;height:9px}
.nav-toggle__bars::before,.nav-toggle__bars::after{
  content:"";position:absolute;left:0;right:0;height:1.5px;background:currentColor;
  transition:transform var(--ease),top var(--ease);
}
.nav-toggle__bars::before{top:0}
.nav-toggle__bars::after{top:7px}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::before{top:3.5px;transform:rotate(45deg)}
.nav-toggle[aria-expanded="true"] .nav-toggle__bars::after{top:3.5px;transform:rotate(-45deg)}

/* 侧边轨道（移动端为抽屉） */
.rail{
  position:fixed;top:var(--topbar-h);left:0;bottom:0;width:min(330px,86vw);z-index:75;
  display:flex;flex-direction:column;gap:20px;
  padding:22px 20px 26px;
  background-color:var(--ink-700);
  background-image:
    linear-gradient(rgba(246,242,233,.05) 1px,transparent 1px),
    linear-gradient(90deg,rgba(246,242,233,.05) 1px,transparent 1px);
  background-size:22px 22px;
  border-right:1px solid rgba(246,242,233,.12);
  color:var(--paper);
  overflow-y:auto;
  transform:translateX(-102%);
  transition:transform .22s cubic-bezier(.2,.7,.3,1);
}
.site-header[data-open] .rail{transform:translateX(0)}
.rail__brand{
  position:relative;display:flex;flex-direction:column;gap:6px;
  padding-bottom:16px;border-bottom:1px solid rgba(246,242,233,.16);
}
.rail__mark{font-family:var(--font-display);font-weight:700;font-size:19px;line-height:1.3;letter-spacing:-.01em;color:var(--paper)}
.rail__sub{font-size:11px;letter-spacing:.08em;color:var(--mist)}
.version{
  position:absolute;top:0;right:0;
  font-size:11px;letter-spacing:.04em;
  background:var(--copper-light);color:var(--ink-900);
  padding:2px 6px;
}
.rail__hint{
  font-size:12px;line-height:1.65;color:var(--mist);
  border-left:1px solid var(--copper);padding-left:10px;max-width:22ch;
}
.rail-nav{flex:1 1 auto}
.rail-nav__list{display:flex;flex-direction:column;gap:2px}
.rail-nav__link{
  display:flex;align-items:baseline;gap:10px;
  padding:9px 10px;
  border-left:2px solid transparent;
  color:rgba(246,242,233,.74);
  transition:background-color var(--ease),color var(--ease),border-color var(--ease);
}
.rail-nav__no{font-size:11px;letter-spacing:.06em;color:var(--mist)}
.rail-nav__label{font-family:var(--font-display);font-weight:600;font-size:15px}
.rail-nav__link:hover{background:rgba(246,242,233,.07);color:var(--paper);border-left-color:var(--copper)}
.rail-nav__link[aria-current="page"]{background:var(--paper);color:var(--ink-900);border-left-color:var(--signal)}
.rail-nav__link[aria-current="page"] .rail-nav__no{color:var(--copper)}
.rail__foot{display:flex;flex-direction:column;gap:12px;padding-top:16px;border-top:1px solid rgba(246,242,233,.16)}
.rail__coord{font-size:11px;letter-spacing:.06em;color:var(--mist)}
.rail__util{display:flex;flex-direction:column;gap:6px}
.rail__util-link{
  font-size:12.5px;color:var(--mist);
  text-decoration:underline;text-decoration-color:rgba(124,143,163,.55);text-underline-offset:3px;
  transition:color var(--ease);
}
.rail__util-link:hover{color:var(--copper-light);text-decoration-color:var(--copper-light)}
.rail__cta{width:100%;text-align:center}
.scrim{
  position:fixed;inset:0;z-index:74;
  background:rgba(13,27,42,.62);
  opacity:0;visibility:hidden;
  transition:opacity .2s ease,visibility .2s ease;
}
.site-header[data-open] .scrim{opacity:1;visibility:visible}

@media (min-width:1024px){
  body{padding-top:0;padding-left:var(--rail-w)}
  .rail{top:0;width:var(--rail-w);transform:translateX(0);transition:none}
  .mobile-bar{display:none}
  .scrim{display:none}
  .read-progress{left:var(--rail-w)}
  #main-content{scroll-margin-top:16px}
}

/* ===== 7. 页脚 ===== */
.site-footer{
  margin-top:clamp(56px,8vw,110px);
  padding:clamp(38px,5vw,64px) 0 0;
  background-color:var(--ink-900);
  background-image:
    linear-gradient(rgba(246,242,233,.045) 1px,transparent 1px),
    linear-gradient(90deg,rgba(246,242,233,.045) 1px,transparent 1px);
  background-size:26px 26px;
  border-top:2px solid var(--copper);
  color:rgba(246,242,233,.72);
  font-size:14.5px;
}
.foot-grid{display:grid;grid-template-columns:1fr;gap:34px}
.foot-brand__mark{
  font-family:var(--font-serif);font-weight:600;
  font-size:clamp(21px,2.4vw,26px);line-height:1.3;color:var(--paper);
  letter-spacing:.01em;
}
.foot-brand__text{font-size:14px;line-height:1.8;color:rgba(246,242,233,.68);margin-top:12px;max-width:46ch}
.foot-brand__meta{font-size:11.5px;letter-spacing:.1em;color:var(--copper-light);margin-top:14px}
.foot-col__title{
  font-family:var(--font-mono);font-weight:400;font-size:11px;letter-spacing:.2em;
  color:var(--copper-light);
  padding-bottom:10px;margin-bottom:14px;
  border-bottom:1px solid rgba(246,242,233,.16);
}
.foot-links li a{
  display:block;padding:6px 0;
  color:rgba(246,242,233,.72);
  border-bottom:1px solid transparent;
  transition:color var(--ease),border-color var(--ease);
}
.foot-links li a:hover{color:var(--copper-light);border-bottom-color:rgba(224,181,127,.5)}
.foot-links li a[aria-current="page"]{color:var(--paper);border-bottom-color:var(--signal)}
.foot-contact__row{
  display:flex;flex-wrap:wrap;align-items:baseline;gap:8px;
  padding:9px 0;border-bottom:1px solid rgba(246,242,233,.12);
}
.foot-contact__label{font-family:var(--font-mono);font-size:11.5px;letter-spacing:.1em;color:var(--mist);min-width:62px}
.foot-contact__val{font-size:13px;color:var(--paper);word-break:break-all}
.copy-btn{
  margin-left:auto;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.1em;
  padding:3px 8px;
  color:var(--copper-light);border:1px solid rgba(224,181,127,.45);
  transition:background-color var(--ease),color var(--ease),border-color var(--ease);
}
.copy-btn:hover{background:var(--copper-light);color:var(--ink-900)}
.copy-btn.is-done{background:var(--celadon);border-color:var(--celadon);color:#fff}
.foot-note{font-size:12.5px;line-height:1.75;color:var(--mist);margin-top:14px;max-width:42ch}
.foot-legal{
  display:flex;flex-wrap:wrap;align-items:center;gap:10px 22px;
  margin-top:38px;
  padding-top:20px;padding-bottom:26px;
  border-top:1px solid rgba(246,242,233,.14);
  font-size:12.5px;color:var(--mist);
}
.foot-legal__icp{font-size:12px;letter-spacing:.06em;color:rgba(246,242,233,.66)}
.foot-legal__links{display:flex;flex-wrap:wrap;gap:16px}
.foot-legal__links a{
  color:rgba(246,242,233,.66);
  border-bottom:1px solid rgba(246,242,233,.24);
  padding-bottom:1px;
  transition:color var(--ease),border-color var(--ease);
}
.foot-legal__links a:hover{color:var(--copper-light);border-bottom-color:var(--copper-light)}
.foot-legal__copy{margin-left:auto;font-family:var(--font-mono);font-size:12px;color:rgba(246,242,233,.55)}

@media (min-width:700px){
  .foot-grid{grid-template-columns:1fr 1fr}
}
@media (min-width:1024px){
  .foot-grid{grid-template-columns:1.5fr .8fr .8fr 1.35fr;gap:42px}
}

/* ===== 8. 按钮 ===== */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:8px;
  font-family:var(--font-display);font-weight:600;font-size:14px;letter-spacing:.02em;
  padding:11px 18px;
  border:1px solid transparent;
  transition:background-color var(--ease),color var(--ease),border-color var(--ease);
}
.btn--copper{background:var(--copper);border-color:var(--copper);color:#fff}
.btn--copper:hover{background:var(--copper-light);border-color:var(--copper-light);color:var(--ink-900)}
.btn--ghost{background:transparent;border-color:rgba(246,242,233,.36);color:var(--paper)}
.btn--ghost:hover{border-color:var(--copper-light);color:var(--copper-light)}
.btn--line{background:transparent;border-color:var(--ink-900);color:var(--ink-900)}
.btn--line:hover{background:var(--ink-900);color:var(--paper)}
.btn--signal{background:var(--signal);border-color:var(--signal);color:#fff}
.btn--signal:hover{background:var(--ink-900);border-color:var(--ink-900)}

/* ===== 9. 卡片 ===== */
.card{
  position:relative;
  display:flex;flex-direction:column;gap:12px;
  padding:clamp(20px,2.4vw,30px);
  background:var(--white);
  border:1px solid var(--grid);
  transition:transform var(--ease),box-shadow var(--ease),border-color var(--ease);
}
.card:hover{transform:translateY(-2px);border-color:var(--copper);box-shadow:0 14px 28px -20px rgba(13,27,42,.6)}
.card__meta{font-family:var(--font-mono);font-size:11.5px;letter-spacing:.1em;color:var(--copper)}
.card__title{font-family:var(--font-display);font-weight:600;font-size:19px;line-height:1.4;color:var(--ink-900)}
.card__body{font-size:15px;line-height:1.75}
.card__foot{margin-top:auto;padding-top:12px;border-top:1px solid var(--grid);font-size:13px}
.card--paper{background:var(--paper)}
.card--ink{background:var(--ink-700);border-color:rgba(246,242,233,.16);color:rgba(246,242,233,.78)}
.card--ink .card__title{color:var(--paper)}
.card--ink .card__meta{color:var(--copper-light)}
.card--ink .card__foot{border-top-color:rgba(246,242,233,.16)}
.card--ink:hover{border-color:var(--copper)}
.card--focus{border-left:3px solid var(--signal)}

/* ===== 10. 文字组件 ===== */
.display{
  font-family:var(--font-display);font-weight:700;
  font-size:clamp(30px,5vw,58px);line-height:1.12;letter-spacing:-.01em;
  color:var(--ink-900);
}
.serif-title{
  font-family:var(--font-serif);font-weight:600;
  font-size:clamp(22px,3vw,34px);line-height:1.28;color:var(--ink-900);
}
.lede{
  font-family:var(--font-serif);
  font-size:clamp(16px,2vw,19px);line-height:1.85;color:var(--ink-500);
}
.eyebrow{font-family:var(--font-mono);font-size:11.5px;letter-spacing:.22em;color:var(--copper)}
.mono{font-family:var(--font-mono);font-variant-numeric:tabular-nums}
.note{
  padding-left:14px;border-left:1px solid var(--copper);
  font-size:13.5px;line-height:1.75;color:var(--ink-500);
}
.rule{height:1px;border:0;background:var(--grid)}
.chapter-index{font-family:var(--font-mono);font-size:12px;letter-spacing:.16em;color:var(--mist);transition:color var(--ease)}
[data-chapter]{position:relative}
[data-chapter].is-active .chapter-index{color:var(--signal)}
[data-chapter].is-active .chapter-index::before{content:"● ";color:var(--signal)}

/* ===== 11. 标签、面包屑、索引、键值、数字 ===== */
.tag{
  display:inline-flex;align-items:center;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.1em;
  padding:3px 8px;
  border:1px solid var(--grid);color:var(--ink-500);
}
.tag--copper{border-color:var(--copper);color:var(--copper)}
.tag--celadon{border-color:var(--celadon);color:var(--celadon)}
.tag--signal{border-color:var(--signal);color:var(--signal)}
.crumbs{
  display:flex;flex-wrap:wrap;align-items:center;gap:10px;
  padding:18px 0;
  font-family:var(--font-mono);font-size:11.5px;letter-spacing:.08em;color:var(--mist);
}
.crumbs a{color:var(--ink-500);border-bottom:1px solid var(--grid);transition:color var(--ease),border-color var(--ease)}
.crumbs a:hover{color:var(--copper);border-bottom-color:var(--copper)}
.crumbs__sep{color:var(--grid)}
.crumbs [aria-current="page"]{color:var(--ink-900)}
.index-list{border-top:1px solid var(--grid)}
.index-list__item{
  display:flex;flex-wrap:wrap;align-items:baseline;gap:6px 14px;
  padding:14px 0;border-bottom:1px solid var(--grid);
}
.index-list__no{font-family:var(--font-mono);font-size:12px;color:var(--copper);min-width:34px}
.index-list__title{font-family:var(--font-display);font-weight:600;font-size:16.5px;color:var(--ink-900)}
.index-list__desc{flex:1 1 240px;font-size:14px;color:var(--text)}
.index-list__meta{margin-left:auto;font-family:var(--font-mono);font-size:11.5px;color:var(--mist)}
.kv{display:grid;grid-template-columns:auto 1fr;gap:10px 18px;font-size:14px}
.kv dt{font-family:var(--font-mono);font-size:11.5px;letter-spacing:.1em;color:var(--mist)}
.kv dd{color:var(--ink-900)}
.stat{display:flex;flex-direction:column;gap:6px;padding-left:14px;border-left:2px solid var(--copper)}
.stat__num{font-family:var(--font-mono);font-weight:600;font-size:clamp(24px,3.4vw,38px);line-height:1;color:var(--ink-900)}
.stat__label{font-size:13px;color:var(--ink-500)}

/* ===== 12. 图片容器（页面阶段放图） ===== */
.media{
  position:relative;display:block;overflow:hidden;
  background:var(--ink-900);
  border:1px solid var(--grid);
}
.media::after{
  content:"";position:absolute;inset:0;pointer-events:none;
  background-image:
    linear-gradient(rgba(246,242,233,.10) 1px,transparent 1px),
    linear-gradient(90deg,rgba(246,242,233,.10) 1px,transparent 1px);
  background-size:20px 20px;
}
.media__img{width:100%;height:100%;object-fit:cover;display:block}
.media--map{aspect-ratio:16/10}
.media--shot{aspect-ratio:4/3}
.media--city{aspect-ratio:3/4}
.media--wide{aspect-ratio:21/9}
.media__caption{display:block;padding-top:8px;font-family:var(--font-mono);font-size:11.5px;letter-spacing:.06em;color:var(--mist)}

/* ===== 13. 滚动显现 ===== */
html.js [data-reveal]{opacity:0;transform:translateY(8px);transition:opacity var(--ease),transform var(--ease)}
html.js [data-reveal].is-in{opacity:1;transform:none}

/* ===== 14. 动效降级 ===== */
@media (prefers-reduced-motion: reduce){
  html{scroll-behavior:auto}
  *,*::before,*::after{
    animation-duration:.001ms !important;
    animation-iteration-count:1 !important;
    transition-duration:.001ms !important;
  }
  html.js [data-reveal]{opacity:1;transform:none}
  .card:hover{transform:none}
  .read-progress__bar{transition:none}
}