/* =========================================================
   /assets/site.css — 皇官网免费中心 共享外壳样式
   深靛蓝基底 / 鎏金索引 / 朱砂状态 / 米白阅读层
   ========================================================= */

:root{
  --navy-900:#0b1330;
  --navy-800:#101c3d;
  --navy-700:#16244b;
  --navy-600:#1e3060;
  --gold:#c9a24d;
  --gold-bright:#e6c477;
  --gold-dim:rgba(201,162,77,.42);
  --vermilion:#c8402f;
  --vermilion-bright:#e2604a;
  --cream:#f4efe3;
  --cream-2:#e8e0cf;
  --grey-cool:#8d97ad;
  --ink:#0a0f22;
  --line:rgba(201,162,77,.28);
  --line-soft:rgba(141,151,173,.22);
  --radius:2px;
  --wrap:1180px;
  --font-serif:"Songti SC","STSong","Noto Serif SC","Source Han Serif SC",Georgia,"Times New Roman",serif;
  --font-sans:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",sans-serif;
  --font-mono:"SFMono-Regular",Menlo,Consolas,"Liberation Mono","Courier New",monospace;
}

/* ---------- Reset ---------- */
*,*::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,dd{margin:0;}
ul,ol{padding:0;list-style:none;}
img,svg,video{max-width:100%;display:block;}
a{color:inherit;text-decoration:none;}
button{font:inherit;color:inherit;background:none;border:0;padding:0;cursor:pointer;}
table{border-collapse:collapse;width:100%;}

/* ---------- 页面基底 ---------- */
body{
  display:flex;
  flex-direction:column;
  min-height:100vh;
  background-color:var(--navy-900);
  color:var(--cream);
  font-family:var(--font-sans);
  font-size:16px;
  line-height:1.85;
  letter-spacing:.01em;
  -webkit-font-smoothing:antialiased;
}
@media (min-width:861px){
  body{
    background-image:
      linear-gradient(rgba(201,162,77,.05) 1px,transparent 1px),
      linear-gradient(90deg,rgba(201,162,77,.05) 1px,transparent 1px);
    background-size:72px 72px,72px 72px;
    background-attachment:fixed;
  }
}
#main-content{flex:1 0 auto;scroll-margin-top:112px;}

/* ---------- 焦点与可达性 ---------- */
:focus-visible{outline:2px solid var(--gold-bright);outline-offset:3px;}
.skip-link{
  position:absolute;left:16px;top:-120px;z-index:120;
  padding:12px 22px;
  background:var(--gold);color:var(--navy-900);
  font-family:var(--font-mono);font-size:12px;letter-spacing:.16em;
  border-radius:var(--radius);
  transition:top .18s ease;
}
.skip-link:focus{top:10px;}

/* ---------- 容器与章节 ---------- */
.container{width:100%;max-width:var(--wrap);margin:0 auto;padding:0 24px;}
.section{padding:clamp(48px,7vw,96px) 0;}
.section--tight{padding:clamp(30px,4vw,56px) 0;}
.section-head{
  display:flex;flex-wrap:wrap;align-items:flex-end;justify-content:space-between;
  gap:16px;margin-bottom:clamp(24px,3vw,42px);
}

/* ---------- 文字层级 ---------- */
.display{
  font-family:var(--font-serif);
  font-size:clamp(2.1rem,6vw,4.3rem);
  font-weight:700;line-height:1.1;letter-spacing:.06em;
  color:var(--cream);
}
.display em{font-style:normal;color:var(--gold-bright);}
.h2{
  font-family:var(--font-serif);
  font-size:clamp(1.5rem,3vw,2.2rem);
  font-weight:700;line-height:1.28;letter-spacing:.05em;
}
.h3{
  font-family:var(--font-serif);
  font-size:1.08rem;font-weight:700;line-height:1.5;letter-spacing:.09em;
}
.eyebrow{
  display:flex;align-items:center;gap:12px;
  font-family:var(--font-mono);font-size:11px;
  letter-spacing:.34em;text-transform:uppercase;
  color:var(--gold);
}
.eyebrow::before{content:"";width:28px;height:1px;background:var(--gold);opacity:.75;}
.lede{font-size:clamp(1rem,1.5vw,1.14rem);line-height:1.9;color:rgba(244,239,227,.78);max-width:62ch;}
.prose{max-width:70ch;}
.prose p+p{margin-top:1em;}
.prose strong{color:var(--gold-bright);font-weight:700;}
.mono{font-family:var(--font-mono);letter-spacing:.06em;}
.num-badge{font-family:var(--font-mono);font-size:12px;letter-spacing:.22em;color:var(--gold);}

/* ---------- 分割线与标签 ---------- */
.rule{height:1px;border:0;background:var(--line-soft);}
.keyline{height:1px;border:0;background:linear-gradient(90deg,var(--gold),rgba(201,162,77,0));}
.tag{
  display:inline-block;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.18em;
  padding:4px 10px;border:1px solid var(--line);color:var(--gold-bright);
  border-radius:var(--radius);
}
.tag--ember{border-color:rgba(200,64,47,.55);color:var(--vermilion-bright);}

/* ---------- 按钮 ---------- */
.btn{
  display:inline-flex;align-items:center;justify-content:center;gap:10px;
  padding:13px 24px;
  border:1px solid var(--line);
  border-radius:var(--radius);
  font-family:var(--font-mono);font-size:12px;letter-spacing:.2em;
  color:var(--cream);
  transition:background .22s ease,color .22s ease,border-color .22s ease;
}
.btn:hover{border-color:var(--gold);color:var(--gold-bright);background:rgba(201,162,77,.09);}
.btn--gold{background:var(--gold);border-color:var(--gold);color:var(--navy-900);font-weight:700;}
.btn--gold:hover{background:var(--gold-bright);border-color:var(--gold-bright);color:var(--navy-900);}
.btn--ember{background:var(--vermilion);border-color:var(--vermilion);color:var(--cream);}
.btn--ember:hover{background:var(--vermilion-bright);border-color:var(--vermilion-bright);color:var(--cream);}
.btn-group{display:flex;flex-wrap:wrap;gap:12px;}

/* ---------- 面包屑 ---------- */
.crumbs{padding:18px 0;border-bottom:1px solid var(--line-soft);}
.crumbs ol{
  display:flex;flex-wrap:wrap;align-items:center;gap:10px;
  font-family:var(--font-mono);font-size:12px;letter-spacing:.14em;
  color:var(--grey-cool);
}
.crumbs li{display:flex;align-items:center;gap:10px;}
.crumbs li+li::before{content:"/";color:var(--gold);opacity:.6;}
.crumbs a{color:rgba(244,239,227,.72);transition:color .2s ease;}
.crumbs a:hover{color:var(--gold-bright);}

/* ---------- 网格 ---------- */
.grid{display:grid;gap:clamp(16px,2.4vw,28px);}
.grid--2{grid-template-columns:repeat(2,minmax(0,1fr));}
.grid--3{grid-template-columns:repeat(3,minmax(0,1fr));}
.grid--asym{grid-template-columns:minmax(0,1.35fr) minmax(0,.85fr);}
.grid--rail{grid-template-columns:minmax(0,180px) minmax(0,1fr);}
@media (max-width:1024px){
  .grid--3{grid-template-columns:repeat(2,minmax(0,1fr));}
}
@media (max-width:760px){
  .grid--2,.grid--3,.grid--asym,.grid--rail{grid-template-columns:minmax(0,1fr);}
}

/* ---------- 卡片与阅读面板 ---------- */
.card{
  position:relative;
  padding:clamp(20px,2.4vw,30px);
  background:rgba(255,255,255,.045);
  border:1px solid var(--line-soft);
  border-radius:var(--radius);
  backdrop-filter:blur(6px);
  transition:border-color .25s ease,background .25s ease,transform .25s ease;
}
.card:hover{border-color:var(--gold-dim);background:rgba(255,255,255,.072);}
.card--accent{border-top:2px solid var(--gold);}
.card--ember{border-top:2px solid var(--vermilion);}

.panel{
  padding:clamp(24px,4vw,46px);
  background:var(--cream);
  color:var(--ink);
  border-radius:var(--radius);
}
.panel .h2,.panel .h3,.panel .display{color:var(--navy-900);}
.panel p{color:#2b3350;}
.panel .lede{color:#3a4460;}
.panel .rule{background:rgba(10,15,34,.14);}

/* ---------- 图片容器（页面阶段放占位图） ---------- */
.figure{
  position:relative;overflow:hidden;
  background:var(--navy-700);
  border:1px solid var(--line-soft);
  border-radius:var(--radius);
}
.figure img{width:100%;height:100%;object-fit:cover;}
.figure--16x9{aspect-ratio:16/9;}
.figure--4x3{aspect-ratio:4/3;}
.figure--3x4{aspect-ratio:3/4;}
.figure--1x1{aspect-ratio:1/1;}
.figure--wide{aspect-ratio:21/9;}
.figure--tall{aspect-ratio:2/3;}
.figure__cap{
  margin-top:10px;
  font-family:var(--font-mono);font-size:11px;letter-spacing:.14em;
  color:var(--grey-cool);
}

/* ---------- 显现动效 ---------- */
.has-js [data-reveal]{
  opacity:0;
  transform:translateY(20px);
  transition:opacity .6s ease,transform .6s ease;
}
.has-js [data-reveal].is-visible{opacity:1;transform:none;}

/* =========================================================
   Header — 框架式导航
   ========================================================= */
.site-header{
  position:sticky;top:0;z-index:80;
  background:rgba(11,19,48,.95);
  border-bottom:1px solid var(--line);
  backdrop-filter:blur(10px);
}
.header-inner{
  position:relative;
  width:100%;max-width:var(--wrap);
  margin:0 auto;padding:12px 24px;
  display:flex;align-items:center;justify-content:space-between;gap:28px;
}
.header-inner::before,
.header-inner::after{
  content:"";position:absolute;top:14px;bottom:14px;width:1px;
  background:linear-gradient(180deg,transparent,var(--gold-dim),transparent);
}
.header-inner::before{left:0;}
.header-inner::after{right:0;}

.brand{display:flex;align-items:center;gap:14px;min-width:0;}
.brand-mark{
  flex:0 0 44px;width:44px;height:44px;
  display:grid;place-items:center;
  font-family:var(--font-serif);font-size:22px;font-weight:700;line-height:1;
  color:var(--navy-900);
  background:linear-gradient(135deg,var(--gold-bright),var(--gold));
  border-radius:var(--radius);
  box-shadow:0 0 0 1px rgba(230,196,119,.5),0 6px 18px -10px rgba(230,196,119,.9);
}
.brand-text{display:flex;flex-direction:column;line-height:1.3;min-width:0;}
.brand-name{
  font-family:var(--font-serif);font-size:17px;font-weight:700;
  letter-spacing:.16em;color:var(--cream);white-space:nowrap;
}
.brand-meta{
  font-family:var(--font-mono);font-size:10px;letter-spacing:.22em;
  color:var(--grey-cool);white-space:nowrap;
}

/* 桌面导航 */
.primary-nav{display:flex;align-items:center;}
.nav-list{display:flex;align-items:stretch;}
.nav-list>li{position:relative;}
.nav-link{
  position:relative;display:flex;flex-direction:column;gap:4px;
  padding:10px 16px 14px;
  font-size:14px;letter-spacing:.16em;line-height:1.4;
  color:rgba(244,239,227,.7);
  transition:color .2s ease,background .2s ease;
  white-space:nowrap;
}
.nav-link::after{
  content:"";position:absolute;left:16px;right:16px;bottom:7px;height:1px;
  background:var(--gold);
  transform:scaleX(0);transform-origin:left;
  transition:transform .24s ease,background .24s ease;
}
.nav-link:hover{color:var(--cream);}
.nav-link:hover::after{transform:scaleX(1);}
.nav-link[aria-current="page"]{color:var(--gold-bright);background:rgba(201,162,77,.07);}
.nav-link[aria-current="page"]::after{transform:scaleX(1);background:var(--vermilion-bright);}
.nav-index{font-family:var(--font-mono);font-size:9px;letter-spacing:.26em;color:var(--grey-cool);}
.nav-link[aria-current="page"] .nav-index{color:var(--vermilion-bright);}
.nav-text{font-family:var(--font-serif);}

/* 移动端按钮 */
.nav-toggle{
  display:none;align-items:center;gap:10px;
  padding:10px 14px;
  border:1px solid var(--line);border-radius:var(--radius);
  font-family:var(--font-mono);font-size:11px;letter-spacing:.22em;
  color:var(--cream);
  transition:border-color .2s ease,color .2s ease;
}
.nav-toggle:hover{border-color:var(--gold);color:var(--gold-bright);}
.nav-toggle-icon{display:grid;gap:4px;width:18px;}
.nav-toggle-bar{display:block;width:18px;height:1px;background:currentColor;transition:opacity .2s ease,transform .2s ease;}
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(2){opacity:0;}
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(1){transform:translateY(2.5px) rotate(20deg);}
.nav-toggle[aria-expanded="true"] .nav-toggle-bar:nth-child(3){transform:translateY(-2.5px) rotate(-20deg);}

/* 阅读进度轨道 */
.header-track{height:2px;background:rgba(201,162,77,.14);overflow:hidden;}
.track-fill{
  display:block;width:0;height:100%;
  background:linear-gradient(90deg,var(--gold),var(--vermilion-bright));
  transition:width .12s linear;
}

@media (max-width:860px){
  .header-inner{padding:10px 18px;gap:14px;}
  .header-inner::before,.header-inner::after{display:none;}
  .brand-mark{flex-basis:38px;width:38px;height:38px;font-size:19px;}
  .brand-name{font-size:15px;letter-spacing:.12em;}
  .brand-meta{display:none;}
  .nav-toggle{display:inline-flex;}
  .primary-nav{
    position:absolute;top:100%;left:0;right:0;
    display:block;
    padding:8px 18px 20px;
    background:rgba(11,19,48,.985);
    border-top:1px solid var(--line);
    border-bottom:1px solid var(--line);
    max-height:calc(100vh - 64px);
    overflow-y:auto;
    opacity:0;visibility:hidden;transform:translateY(-10px);
    transition:opacity .22s ease,transform .22s ease,visibility .22s;
  }
  .primary-nav[data-open]{opacity:1;visibility:visible;transform:translateY(0);}
  .nav-list{flex-direction:column;align-items:stretch;}
  .nav-list>li{border-bottom:1px dashed rgba(141,151,173,.2);}
  .nav-list>li:last-child{border-bottom:0;}
  .nav-link{flex-direction:row;align-items:baseline;gap:14px;padding:15px 8px;font-size:15px;}
  .nav-link::after{display:none;}
  .nav-link[aria-current="page"]{
    padding-left:16px;
    background:linear-gradient(90deg,rgba(201,162,77,.16),rgba(201,162,77,0));
  }
}

/* =========================================================
   Footer — 归档层
   ========================================================= */
.site-footer{
  margin-top:auto;
  background:linear-gradient(180deg,rgba(16,28,61,.72),var(--navy-900));
  border-top:1px solid var(--line);
}
.footer-inner{
  width:100%;max-width:var(--wrap);
  margin:0 auto;
  padding:clamp(40px,6vw,72px) 24px 32px;
  display:grid;gap:36px;
  grid-template-columns:minmax(0,1.5fr) minmax(0,1fr) minmax(0,1.3fr);
}
.footer-brand{min-width:0;}
.footer-mark{
  display:grid;place-items:center;
  width:48px;height:48px;margin-bottom:16px;
  font-family:var(--font-serif);font-size:24px;font-weight:700;line-height:1;
  color:var(--gold-bright);
  border:1px solid var(--line);
  background:rgba(201,162,77,.08);
  border-radius:var(--radius);
}
.footer-name{
  font-family:var(--font-serif);font-size:19px;font-weight:700;
  letter-spacing:.16em;color:var(--cream);
}
.footer-desc{
  margin-top:10px;max-width:34ch;
  font-size:13.5px;line-height:1.85;color:rgba(244,239,227,.6);
}
.footer-col{min-width:0;}
.footer-title{
  margin-bottom:16px;
  font-family:var(--font-mono);font-size:11px;font-weight:400;
  letter-spacing:.26em;text-transform:uppercase;color:var(--gold);
}
.footer-links li+li{margin-top:10px;}
.footer-links a{
  font-size:14px;letter-spacing:.08em;
  color:rgba(244,239,227,.74);
  transition:color .2s ease;
}
.footer-links a:hover{color:var(--gold-bright);}
.footer-contact li{
  display:flex;gap:12px;
  font-size:13.5px;line-height:1.9;
  color:rgba(244,239,227,.74);
}
.footer-contact li+li{margin-top:8px;}
.footer-contact .mono{
  flex:0 0 40px;
  font-size:11px;letter-spacing:.18em;color:var(--gold);
  padding-top:3px;
}
.footer-contact span:last-child{word-break:break-all;}
.footer-note{
  margin-top:16px;max-width:40ch;
  font-size:12.5px;line-height:1.85;color:var(--grey-cool);
}
.footer-bottom{
  width:100%;max-width:var(--wrap);
  margin:0 auto;
  padding:18px 24px 28px;
  border-top:1px solid var(--line-soft);
  display:flex;flex-wrap:wrap;gap:12px;
  align-items:center;justify-content:space-between;
  font-family:var(--font-mono);font-size:11.5px;letter-spacing:.1em;
  color:var(--grey-cool);
}
.footer-bottom .mono{color:rgba(244,239,227,.72);}

@media (max-width:900px){
  .footer-inner{grid-template-columns:minmax(0,1fr);gap:32px;padding-top:40px;}
  .footer-desc{max-width:48ch;}
}
@media (max-width:520px){
  .footer-bottom{flex-direction:column;align-items:flex-start;}
}

/* ---------- 减少动效 ---------- */
@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;
  }
  .has-js [data-reveal]{opacity:1 !important;transform:none !important;}
  .track-fill{transition:none;}
}