/* ==========================================================================
   开元官方 · 数字门册 / site.css
   共享层：reset、变量、中文排版、头部、页脚、通用组件
   ========================================================================== */

:root{
  --ink-teal:#0E2A2F;
  --ink-deep:#071B1E;
  --slate:#DDE6E3;
  --paper:#F2F5F2;
  --copper:#B8833E;
  --copper-bright:#D6A35C;
  --amber:#F2B45A;
  --celadon:#4F7C74;
  --cinnabar:#A64B2A;
  --ink:#111817;
  --white:#FFFFFF;

  --rail-w:252px;
  --line:rgba(184,131,62,.34);
  --hairline:rgba(14,42,47,.16);
  --hairline-soft:rgba(14,42,47,.09);

  --font-serif:"Source Han Serif SC","Noto Serif SC","Songti SC","Songti TC",SimSun,serif;
  --font-sans:"Noto Sans SC","PingFang SC","Hiragino Sans GB","Microsoft YaHei",system-ui,-apple-system,sans-serif;
  --font-mono:"IBM Plex Mono","JetBrains Mono",ui-monospace,SFMono-Regular,Menlo,Consolas,monospace;

  --ease:cubic-bezier(.32,.72,0,1);
  --gutter:clamp(16px,4vw,44px);
}

/* ---------- reset ---------- */
*,*::before,*::after{box-sizing:border-box;}
html{
  -webkit-text-size-adjust:100%;
  text-size-adjust:100%;
  scroll-behavior:smooth;
}
body{
  margin:0;
  padding:0;
  background:var(--paper);
  color:var(--ink);
  font-family:var(--font-sans);
  font-size:17px;
  line-height:1.75;
  letter-spacing:.01em;
  -webkit-font-smoothing:antialiased;
  text-rendering:optimizeLegibility;
}
img,svg,video{max-width:100%;}
img{height:auto;}
button,input,select,textarea{font:inherit;color:inherit;}
a{color:inherit;}
ul,ol{margin:0;padding:0;}
p{margin:0;}
hr{border:0;}

/* ---------- 排版 ---------- */
h1,h2,h3,h4,h5{
  margin:0;
  font-family:var(--font-serif);
  font-weight:600;
  line-height:1.18;
  letter-spacing:.015em;
  color:var(--ink-teal);
}
h1{font-size:clamp(44px,6.5vw,96px);}
h2{font-size:clamp(28px,3.6vw,52px);}
h3{font-size:clamp(20px,2.1vw,28px);}
h4{font-size:clamp(17px,1.6vw,20px);}
.lede{
  font-size:clamp(17px,1.5vw,20px);
  line-height:1.8;
  max-width:38em;
  color:rgba(17,24,23,.78);
}
.mono{
  font-family:var(--font-mono);
  font-size:.74rem;
  letter-spacing:.1em;
  line-height:1.6;
}
.meta{
  font-family:var(--font-mono);
  font-size:.7rem;
  letter-spacing:.12em;
  color:var(--celadon);
  display:block;
}
.eyebrow{
  margin:0 0 .9rem;
  font-family:var(--font-mono);
  font-size:.68rem;
  letter-spacing:.22em;
  text-transform:uppercase;
  color:var(--copper);
}
.section--ink h1,.section--ink h2,.section--ink h3,.section--ink h4{color:var(--paper);}
.section--ink .lede{color:rgba(242,245,242,.8);}
.section--ink .eyebrow{color:var(--copper-bright);}

/* ---------- 焦点 ---------- */
:focus-visible{
  outline:2px solid var(--amber);
  outline-offset:2px;
  box-shadow:0 0 0 1px var(--ink-deep);
}

/* ---------- 布局 ---------- */
.container{
  width:100%;
  max-width:1200px;
  margin-inline:auto;
  padding-inline:var(--gutter);
}
main{display:block;background:var(--paper);}
#main-content{scroll-margin-top:88px;}
.section{padding-block:clamp(40px,6vw,80px);}
.section--slate{background:var(--slate);color:var(--ink);}
.section--ink{background:var(--ink-teal);color:var(--paper);}
.rule{
  height:1px;
  border:0;
  background:linear-gradient(90deg,var(--copper),rgba(184,131,62,0));
}
.grid{display:grid;gap:clamp(20px,3.4vw,40px);grid-template-columns:1fr;}
@media (min-width:900px){
  .grid--7-5{grid-template-columns:7fr 5fr;}
  .grid--8-4{grid-template-columns:8fr 4fr;}
  .grid--5-7{grid-template-columns:5fr 7fr;}
}

/* ---------- 按钮 ---------- */
.btn{
  display:inline-flex;
  align-items:center;
  gap:.6em;
  padding:.72em 1.35em;
  border:1px solid var(--copper);
  border-radius:0;
  background:var(--copper);
  color:var(--white);
  font-family:var(--font-sans);
  font-size:.95rem;
  letter-spacing:.04em;
  text-decoration:none;
  cursor:pointer;
  transition:background .2s var(--ease),border-color .2s var(--ease),color .2s var(--ease);
}
.btn:hover{background:var(--copper-bright);border-color:var(--copper-bright);color:var(--ink-deep);}
.btn--ghost{background:transparent;color:var(--ink-teal);border-color:var(--copper);}
.btn--ghost:hover{background:rgba(184,131,62,.12);color:var(--ink-teal);border-color:var(--copper-bright);}

/* ---------- 面包屑 ---------- */
.breadcrumb{margin-bottom:clamp(16px,2vw,26px);}
.breadcrumb__list{
  list-style:none;
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  gap:.6em;
  font-family:var(--font-mono);
  font-size:.68rem;
  letter-spacing:.14em;
  color:rgba(14,42,47,.62);
}
.breadcrumb__list li{display:flex;align-items:center;}
.breadcrumb__list li + li::before{content:"/";margin-right:.6em;color:var(--copper);}
.breadcrumb a{
  color:var(--celadon);
  text-decoration:none;
  border-bottom:1px solid transparent;
  transition:color .2s var(--ease),border-color .2s var(--ease);
}
.breadcrumb a:hover{color:var(--copper);border-bottom-color:var(--copper);}

/* ---------- 面板 ---------- */
.panel{
  position:relative;
  background:var(--white);
  border:1px solid var(--hairline);
  border-radius:0;
  padding:clamp(18px,2.6vw,30px);
}
.panel--ink{
  background:var(--ink-teal);
  border-color:var(--line);
  color:var(--paper);
}
.panel--ink h2,.panel--ink h3,.panel--ink h4{color:var(--paper);}
.panel__index{
  display:block;
  margin-bottom:.7rem;
  font-family:var(--font-mono);
  font-size:.68rem;
  letter-spacing:.2em;
  color:var(--copper);
}
.panel--ink .panel__index{color:var(--copper-bright);}

/* ---------- 图片容器（页面阶段放入 img / svg 占位） ---------- */
.figure{margin:0;display:grid;gap:.7rem;}
.figure__media{
  position:relative;
  overflow:hidden;
  aspect-ratio:16 / 10;
  border:1px solid var(--line);
  background-color:var(--slate);
  background-image:
    linear-gradient(135deg,rgba(14,42,47,.07) 25%,transparent 25%,transparent 50%,rgba(14,42,47,.07) 50%,rgba(14,42,47,.07) 75%,transparent 75%);
  background-size:14px 14px;
}
.figure__media::after{
  content:"";
  position:absolute;
  inset:10px;
  border:1px solid rgba(184,131,62,.36);
  pointer-events:none;
}
.figure__media > img,
.figure__media > svg{
  display:block;
  width:100%;
  height:100%;
  object-fit:cover;
}
.figure__media--portrait{aspect-ratio:4 / 5;}
.figure__media--square{aspect-ratio:1 / 1;}
.figure__caption{
  font-family:var(--font-mono);
  font-size:.7rem;
  letter-spacing:.08em;
  line-height:1.7;
  color:var(--celadon);
}

/* ==========================================================================
   头部
   ========================================================================== */
.skip-link{
  position:fixed;
  top:10px;
  left:12px;
  z-index:200;
  transform:translateY(-180%);
  padding:.62em 1.1em;
  background:var(--amber);
  color:var(--ink-deep);
  font-family:var(--font-mono);
  font-size:.76rem;
  letter-spacing:.1em;
  text-decoration:none;
  border:1px solid var(--copper);
  transition:transform .18s var(--ease);
}
.skip-link:focus{transform:translateY(0);}

.site-header{
  position:sticky;
  top:0;
  left:0;
  right:0;
  z-index:80;
  background:var(--ink-teal);
  color:var(--paper);
  border-bottom:1px solid var(--line);
}
.site-header__inner{
  display:flex;
  align-items:center;
  gap:12px;
  min-height:62px;
  padding:10px clamp(12px,4vw,22px);
}

/* 品牌 + 门框标记 */
.brand{
  display:inline-flex;
  align-items:center;
  gap:10px;
  margin-right:auto;
  min-width:0;
  color:inherit;
  text-decoration:none;
}
.brand__mark{
  position:relative;
  flex:none;
  width:26px;
  height:26px;
  border:1px solid var(--copper);
  display:block;
}
.brand__mark::before{
  content:"";
  position:absolute;
  inset:6px 6px -1px 6px;
  border-left:1px solid var(--copper-bright);
  border-top:1px solid var(--copper-bright);
}
.brand__text{display:flex;flex-direction:column;min-width:0;line-height:1.25;}
.brand__line{
  font-family:var(--font-serif);
  font-size:1rem;
  letter-spacing:.06em;
  white-space:nowrap;
  overflow:hidden;
  text-overflow:ellipsis;
}
.brand__sub{
  font-family:var(--font-mono);
  font-size:.62rem;
  letter-spacing:.16em;
  color:var(--copper-bright);
  white-space:nowrap;
}

/* 版本切换 */
.version-switch{
  display:inline-flex;
  align-items:baseline;
  gap:.5em;
  flex:none;
  padding:.42em .62em;
  border:1px solid var(--line);
  color:var(--copper-bright);
  font-family:var(--font-mono);
  font-size:.68rem;
  letter-spacing:.12em;
  text-decoration:none;
  white-space:nowrap;
  transition:background .2s var(--ease),border-color .2s var(--ease),color .2s var(--ease);
}
.version-switch:hover{
  background:var(--copper-bright);
  border-color:var(--copper-bright);
  color:var(--ink-deep);
}
.version-switch__label{display:none;}
.version-switch__value{color:inherit;}

/* 抽屉按钮 */
.nav-toggle{
  display:inline-flex;
  align-items:center;
  gap:8px;
  flex:none;
  padding:.5em .7em;
  border:1px solid var(--line);
  border-radius:0;
  background:transparent;
  color:var(--paper);
  font-family:var(--font-mono);
  font-size:.68rem;
  letter-spacing:.14em;
  cursor:pointer;
  transition:border-color .2s var(--ease),color .2s var(--ease);
}
.nav-toggle:hover{border-color:var(--copper-bright);color:var(--amber);}
.nav-toggle__bars{display:inline-flex;flex-direction:column;gap:3px;width:16px;}
.nav-toggle__bars span{
  display:block;
  height:1px;
  background:var(--copper-bright);
  transition:transform .22s var(--ease),opacity .18s var(--ease);
}
.site-header[data-open] .nav-toggle__bars span:nth-child(1){transform:translateY(4px) rotate(45deg);}
.site-header[data-open] .nav-toggle__bars span:nth-child(2){opacity:0;}
.site-header[data-open] .nav-toggle__bars span:nth-child(3){transform:translateY(-4px) rotate(-45deg);}

/* 导航（移动端抽屉） */
.site-nav{
  position:absolute;
  top:100%;
  left:0;
  right:0;
  display:block;
  max-height:0;
  overflow:hidden;
  visibility:hidden;
  opacity:0;
  background:var(--ink-deep);
  border-bottom:1px solid var(--line);
  transition:max-height .3s var(--ease),opacity .2s var(--ease),visibility .2s linear;
}
.site-header[data-open] .site-nav{
  max-height:min(72vh,540px);
  overflow-y:auto;
  visibility:visible;
  opacity:1;
}
.site-nav__label{
  padding:14px 1.15em 8px;
  font-family:var(--font-mono);
  font-size:.62rem;
  letter-spacing:.24em;
  color:var(--copper-bright);
  text-transform:uppercase;
}
.site-nav__list{list-style:none;}
.site-nav__item{list-style:none;}
.site-nav__link{
  display:flex;
  align-items:baseline;
  gap:.85em;
  padding:.82em 1.15em;
  color:var(--paper);
  font-size:.98rem;
  letter-spacing:.02em;
  text-decoration:none;
  border-bottom:1px solid rgba(255,255,255,.06);
  transition:background .2s var(--ease),color .2s var(--ease);
}
.site-nav__link:hover{background:rgba(184,131,62,.16);color:var(--amber);}
.site-nav__num{
  flex:none;
  font-family:var(--font-mono);
  font-size:.68rem;
  letter-spacing:.12em;
  color:var(--copper-bright);
  transition:color .2s var(--ease);
}
.site-nav__text{display:inline-block;}
.site-nav__link[aria-current="page"]{
  background:rgba(184,131,62,.2);
  color:var(--amber);
  box-shadow:inset 3px 0 0 var(--amber);
}
.site-nav__link[aria-current="page"] .site-nav__num{color:var(--amber);}
.site-nav__note{
  padding:14px 1.15em 18px;
  font-family:var(--font-mono);
  font-size:.66rem;
  line-height:1.7;
  letter-spacing:.06em;
  color:rgba(221,230,227,.55);
  border-top:1px solid rgba(255,255,255,.06);
}

.site-header__aside{display:none;}
.aside__caption{
  font-family:var(--font-mono);
  font-size:.62rem;
  letter-spacing:.2em;
  color:var(--copper-bright);
}
.aside__value{
  font-size:.8rem;
  letter-spacing:.06em;
  color:rgba(242,245,242,.72);
}

/* 滚动进度刻度 */
.rail-progress{
  position:absolute;
  left:0;
  right:0;
  bottom:0;
  height:2px;
  pointer-events:none;
  background:rgba(184,131,62,.16);
}
.rail-progress__bar{
  display:block;
  width:100%;
  height:100%;
  transform-origin:left center;
  transform:scaleX(var(--p,0));
  background:linear-gradient(90deg,var(--copper),var(--amber));
  transition:transform .12s linear;
}

/* 返回顶部 */
.to-top{
  position:fixed;
  right:14px;
  bottom:14px;
  z-index:120;
  display:inline-flex;
  align-items:center;
  justify-content:center;
  width:44px;
  height:44px;
  padding:0;
  border:1px solid var(--line);
  border-radius:0;
  background:var(--ink-teal);
  color:var(--amber);
  font-family:var(--font-mono);
  font-size:.9rem;
  cursor:pointer;
  opacity:0;
  visibility:hidden;
  transform:translateY(10px);
  transition:opacity .24s var(--ease),transform .24s var(--ease),visibility .24s linear,background .2s var(--ease),color .2s var(--ease);
}
.to-top[data-visible]{opacity:1;visibility:visible;transform:none;}
.to-top:hover{background:var(--copper);color:var(--ink-deep);border-color:var(--copper-bright);}

/* 小屏压缩 */
@media (max-width:419px){
  .site-header__inner{gap:8px;padding:9px 12px;min-height:56px;}
  .brand__sub{display:none;}
  .nav-toggle__label{display:none;}
  .nav-toggle{padding:.5em;}
  .brand__line{font-size:.94rem;}
}

/* ---------- 桌面端：侧边轨道 ---------- */
@media (min-width:1024px){
  body{padding-left:var(--rail-w);}

  .site-header{
    position:fixed;
    inset:0 auto 0 0;
    width:var(--rail-w);
    display:flex;
    border-bottom:0;
    border-right:1px solid var(--line);
  }
  .site-header__inner{
    display:flex;
    flex-direction:column;
    align-items:stretch;
    gap:20px;
    width:100%;
    height:100%;
    min-height:0;
    padding:26px 20px 24px;
  }
  .brand{
    flex-direction:row;
    align-items:center;
    margin-right:0;
    padding-bottom:20px;
    border-bottom:1px solid var(--line);
  }
  .brand__line{white-space:normal;}
  .brand__sub{font-size:.6rem;letter-spacing:.14em;}

  .version-switch{
    justify-content:space-between;
    padding:.55em .7em;
    font-size:.66rem;
  }
  .version-switch__label{display:inline;}

  .nav-toggle{display:none;}

  .site-nav{
    position:static;
    flex:1 1 auto;
    min-height:0;
    overflow-y:auto;
    max-height:none;
    visibility:visible;
    opacity:1;
    background:transparent;
    border-bottom:0;
    border-top:1px solid var(--line);
    padding-top:18px;
    transition:none;
  }
  .site-nav__label{
    padding:0 0 10px;
    margin:0;
    font-size:.62rem;
  }
  .site-nav__list{display:flex;flex-direction:column;gap:1px;}
  .site-nav__link{
    position:relative;
    padding:.58em .7em .58em .62em;
    border-bottom:0;
    border-left:1px solid transparent;
    font-size:.94rem;
  }
  .site-nav__link::after{
    content:"";
    position:absolute;
    left:0;
    bottom:.3em;
    width:0;
    height:1px;
    background:var(--copper-bright);
    transition:width .28s var(--ease);
  }
  .site-nav__link:hover::after{width:100%;}
  .site-nav__link[aria-current="page"]{
    background:rgba(242,180,90,.1);
    box-shadow:inset 2px 0 0 var(--amber);
  }
  .site-nav__note{display:none;}

  .site-header__aside{
    display:grid;
    gap:4px;
    margin-top:auto;
    padding-top:16px;
    border-top:1px solid var(--line);
  }

  .rail-progress{
    left:auto;
    right:0;
    top:0;
    bottom:0;
    width:2px;
    height:auto;
  }
  .rail-progress__bar{
    transform-origin:top center;
    transform:scaleY(var(--p,0));
    background:linear-gradient(180deg,var(--copper),var(--amber));
  }

  .to-top{right:22px;bottom:22px;}
}

@media (min-width:1280px){
  :root{--rail-w:272px;}
}

/* ==========================================================================
   页脚
   ========================================================================== */
.site-footer{
  background:var(--ink-deep);
  color:rgba(242,245,242,.78);
  border-top:1px solid var(--line);
  font-size:.92rem;
}
.site-footer__inner{padding-top:clamp(36px,5.5vw,64px);padding-bottom:0;}
.site-footer__grid{
  display:grid;
  grid-template-columns:1fr;
  gap:clamp(28px,4.5vw,56px);
  padding-bottom:clamp(28px,4vw,40px);
  border-bottom:1px solid rgba(255,255,255,.08);
}
.footer-brand{
  margin:0 0 6px;
  font-family:var(--font-serif);
  font-size:clamp(24px,3vw,32px);
  letter-spacing:.08em;
  color:var(--paper);
}
.footer-tagline{
  margin:0 0 18px;
  font-family:var(--font-mono);
  font-size:.66rem;
  letter-spacing:.22em;
  color:var(--copper-bright);
}
.footer-contact{display:grid;gap:6px;}
.footer-contact__row{
  display:grid;
  grid-template-columns:56px 1fr;
  gap:10px;
  margin:0;
  font-size:.86rem;
  line-height:1.7;
  color:rgba(242,245,242,.8);
}
.footer-contact__key{
  font-family:var(--font-mono);
  font-size:.64rem;
  letter-spacing:.14em;
  color:var(--copper-bright);
  padding-top:.28em;
}
.footer-note{
  margin-top:16px;
  padding-top:14px;
  border-top:1px solid rgba(255,255,255,.08);
  font-family:var(--font-mono);
  font-size:.66rem;
  line-height:1.8;
  letter-spacing:.04em;
  color:rgba(221,230,227,.55);
  max-width:34em;
}
.footer-nav{
  display:grid;
  grid-template-columns:repeat(2,minmax(0,1fr));
  gap:clamp(20px,4vw,48px);
}
.footer-group{min-width:0;}
.footer-group__title{
  margin:0 0 12px;
  font-family:var(--font-mono);
  font-size:.66rem;
  letter-spacing:.22em;
  color:var(--copper-bright);
  text-transform:uppercase;
}
.footer-group__list{list-style:none;display:grid;gap:9px;}
.footer-group__list a{
  display:inline-block;
  color:rgba(242,245,242,.82);
  text-decoration:none;
  font-size:.94rem;
  padding-bottom:1px;
  border-bottom:1px solid transparent;
  transition:color .2s var(--ease),border-color .2s var(--ease);
}
.footer-group__list a:hover{color:var(--amber);border-bottom-color:var(--amber);}

.site-footer__meta{
  display:flex;
  flex-wrap:wrap;
  align-items:center;
  justify-content:space-between;
  gap:14px;
  padding:20px 0 26px;
}
.footer-legal{
  margin:0;
  font-family:var(--font-mono);
  font-size:.68rem;
  letter-spacing:.06em;
  color:rgba(221,230,227,.58);
}
.footer-legal__links{
  list-style:none;
  display:flex;
  flex-wrap:wrap;
  gap:16px;
  font-family:var(--font-mono);
  font-size:.68rem;
  letter-spacing:.06em;
}
.footer-legal__links a{
  color:rgba(221,230,227,.72);
  text-decoration:none;
  border-bottom:1px solid transparent;
  transition:color .2s var(--ease),border-color .2s var(--ease);
}
.footer-legal__links a:hover{color:var(--amber);border-bottom-color:var(--amber);}

@media (min-width:760px){
  .site-footer__grid{grid-template-columns:minmax(240px,1fr) 1.35fr;}
}
@media (min-width:1024px){
  .site-footer__grid{grid-template-columns:minmax(280px,.9fr) 1.6fr;}
}

/* ==========================================================================
   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;
    scroll-behavior:auto !important;
  }
  .rail-progress__bar{transition:none;}
}