/* =========================================================
   星图 · 天文学体系  —  共享视觉系统
   深邃星空 + 金朱辉光  ·  移动/PC 通用  ·  零依赖
   ========================================================= */

:root{
  --bg:#070912;
  --bg2:#0c1130;
  --panel:rgba(18,24,48,0.66);
  --panel-solid:#121830;
  --ink:#eae8f6;
  --muted:#9aa0c6;
  --faint:#6b7099;
  --gold:#e7be7c;
  --gold-2:#d4af37;
  --cinnabar:#e2604f;
  --cinnabar-2:#c0392b;
  --line:rgba(231,190,124,0.22);
  --line-soft:rgba(154,160,198,0.16);
  --accent:linear-gradient(135deg,#e7be7c 0%,#e2604f 100%);
  --shadow:0 18px 50px -22px rgba(0,0,0,0.85);
  --radius:18px;
  --serif:"Songti SC","STSong","SimSun","Noto Serif SC","Source Han Serif SC",serif;
  --sans:"PingFang SC","Microsoft YaHei","Hiragino Sans GB","Heiti SC",system-ui,-apple-system,sans-serif;
}

*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{
  font-family:var(--sans);
  color:var(--ink);
  background:var(--bg);
  line-height:1.75;
  min-height:100vh;
  overflow-x:hidden;
  -webkit-font-smoothing:antialiased;
  position:relative;
}
/* 星云底色（多层径向渐变，营造深空氛围） */
body::before{
  content:"";position:fixed;inset:0;z-index:-2;
  background:
    radial-gradient(1100px 700px at 12% -8%, rgba(86,64,160,0.30), transparent 60%),
    radial-gradient(900px 600px at 92% 6%, rgba(180,70,80,0.22), transparent 60%),
    radial-gradient(1200px 900px at 50% 120%, rgba(40,80,150,0.22), transparent 60%),
    linear-gradient(180deg,var(--bg) 0%, var(--bg2) 55%, #05070f 100%);
}
/* 星点画布 */
#starfield{position:fixed;inset:0;z-index:-1;width:100%;height:100%;display:block;pointer-events:none}

::selection{background:rgba(231,190,124,0.32);color:#fff}
a{color:inherit;text-decoration:none}
img{max-width:100%;display:block}

/* ---------- 滚动条 ---------- */
::-webkit-scrollbar{width:10px;height:10px}
::-webkit-scrollbar-track{background:transparent}
::-webkit-scrollbar-thumb{background:linear-gradient(var(--gold),var(--cinnabar));border-radius:8px;border:2px solid var(--bg)}

/* ---------- 容器 ---------- */
.wrap{max-width:1160px;margin:0 auto;padding:0 18px}
.wrap-wide{max-width:1320px}

/* ---------- 顶部导航 ---------- */
header.site{
  position:sticky;top:0;z-index:50;
  backdrop-filter:blur(12px);
  background:linear-gradient(180deg,rgba(7,9,18,0.92),rgba(7,9,18,0.55));
  border-bottom:1px solid var(--line-soft);
}
.site-row{display:flex;align-items:center;gap:14px;padding:11px 18px;max-width:1320px;margin:0 auto}
.brand{display:flex;align-items:center;gap:10px;font-family:var(--serif);font-weight:700;font-size:19px;letter-spacing:2px;white-space:nowrap}
.brand .seal{
  width:34px;height:34px;border-radius:9px;flex:0 0 auto;
  background:var(--accent);color:#1a1206;display:grid;place-items:center;
  font-size:18px;box-shadow:0 6px 18px -6px rgba(226,96,79,.6);
}
.brand small{display:block;font-family:var(--sans);font-weight:400;font-size:11px;letter-spacing:1px;color:var(--muted);margin-top:-2px}
.nav{display:flex;gap:4px;margin-left:auto;overflow-x:auto;scrollbar-width:none;padding:4px 2px}
.nav::-webkit-scrollbar{display:none}
.nav a{
  flex:0 0 auto;padding:7px 12px;border-radius:999px;font-size:13.5px;color:var(--muted);
  border:1px solid transparent;transition:.25s;white-space:nowrap;
}
.nav a:hover{color:var(--ink);border-color:var(--line)}
.nav a.active{color:#1a1206;background:var(--accent);font-weight:600;border-color:transparent}

/* ---------- 通用区块 ---------- */
section{padding:54px 0}
.eyebrow{font-size:12.5px;letter-spacing:5px;color:var(--gold);text-transform:uppercase;margin-bottom:10px}
.h2{font-family:var(--serif);font-size:clamp(24px,4vw,34px);letter-spacing:2px;margin-bottom:8px;line-height:1.25}
.lead{color:var(--muted);max-width:760px;font-size:15.5px}
.divider{height:1px;background:linear-gradient(90deg,transparent,var(--line),transparent);margin:6px 0 0}

/* ---------- 英雄区 ---------- */
.hero{position:relative;padding:78px 0 56px;text-align:center;overflow:hidden}
.hero h1{
  font-family:var(--serif);font-weight:700;letter-spacing:6px;
  font-size:clamp(40px,9vw,84px);line-height:1.05;
  background:linear-gradient(180deg,#fff 0%,#f1d9ad 60%,#e7be7c 100%);
  -webkit-background-clip:text;background-clip:text;color:transparent;
  text-shadow:0 0 40px rgba(231,190,124,.18);
}
.hero .sub{color:var(--gold);letter-spacing:8px;font-size:clamp(13px,2.4vw,17px);margin-top:14px}
.hero p.intro{color:var(--muted);max-width:680px;margin:22px auto 0;font-size:15.5px}
.hero .cta{margin-top:30px;display:flex;gap:14px;justify-content:center;flex-wrap:wrap}

/* 旋转星盘装饰 */
.armillary{width:118px;height:118px;margin:0 auto 26px;position:relative;opacity:.92}
.armillary svg{width:100%;height:100%;animation:spin 60s linear infinite}
.armillary .ring2{animation:spin 40s linear infinite reverse;transform-origin:center}
@keyframes spin{to{transform:rotate(360deg)}}

/* ---------- 按钮 ---------- */
.btn{
  display:inline-flex;align-items:center;gap:8px;padding:12px 22px;border-radius:999px;
  font-size:14.5px;font-weight:600;border:1px solid var(--line);color:var(--ink);
  background:var(--panel);transition:.25s;cursor:pointer;
}
.btn:hover{transform:translateY(-2px);border-color:var(--gold);box-shadow:0 10px 26px -12px rgba(231,190,124,.5)}
.btn.primary{background:var(--accent);color:#1a1206;border-color:transparent}
.btn.primary:hover{box-shadow:0 12px 30px -10px rgba(226,96,79,.6)}

/* ---------- 卡片网格 ---------- */
.grid{display:grid;gap:18px}
.grid.cols-2{grid-template-columns:repeat(2,1fr)}
.grid.cols-3{grid-template-columns:repeat(3,1fr)}
.grid.cols-4{grid-template-columns:repeat(4,1fr)}
.card{
  background:var(--panel);border:1px solid var(--line-soft);border-radius:var(--radius);
  padding:22px;position:relative;overflow:hidden;transition:.3s;backdrop-filter:blur(6px);
}
.card:hover{transform:translateY(-4px);border-color:var(--line);box-shadow:var(--shadow)}
.card h3{font-family:var(--serif);font-size:20px;letter-spacing:1px;margin-bottom:6px}
.card .kicker{font-size:12px;letter-spacing:2px;color:var(--gold);margin-bottom:8px}
.card p{color:var(--muted);font-size:14px}
.card .arrow{position:absolute;right:18px;bottom:16px;color:var(--gold);font-size:18px;opacity:.7}

/* 导航卡片（首页板块入口） */
.tile{
  display:block;background:var(--panel);border:1px solid var(--line-soft);border-radius:var(--radius);
  padding:24px 22px;transition:.3s;position:relative;overflow:hidden;
}
.tile::after{content:"";position:absolute;right:-30px;top:-30px;width:120px;height:120px;border-radius:50%;
  background:radial-gradient(circle,rgba(231,190,124,.16),transparent 70%);transition:.4s}
.tile:hover{transform:translateY(-5px);border-color:var(--line);box-shadow:var(--shadow)}
.tile:hover::after{transform:scale(1.5)}
.tile .ico{font-size:30px;margin-bottom:12px}
.tile h3{font-family:var(--serif);font-size:21px;letter-spacing:1px}
.tile .desc{color:var(--muted);font-size:13.5px;margin-top:8px}
.tile .tag{display:inline-block;margin-top:14px;font-size:11.5px;letter-spacing:1px;color:var(--gold);
  border:1px solid var(--line);border-radius:999px;padding:3px 10px}

/* ---------- 标签筛选 ---------- */
.filters{display:flex;gap:8px;flex-wrap:wrap;margin:6px 0 22px}
.chip{padding:7px 15px;border-radius:999px;border:1px solid var(--line-soft);color:var(--muted);
  font-size:13.5px;cursor:pointer;transition:.2s;background:rgba(255,255,255,.02)}
.chip:hover{color:var(--ink);border-color:var(--line)}
.chip.on{background:var(--accent);color:#1a1206;font-weight:600;border-color:transparent}

/* ---------- 搜索框 ---------- */
.search{display:flex;align-items:center;gap:10px;background:var(--panel);border:1px solid var(--line-soft);
  border-radius:999px;padding:10px 16px;max-width:420px;margin-bottom:22px}
.search input{flex:1;background:none;border:none;color:var(--ink);font-size:14.5px;outline:none;font-family:var(--sans)}
.search .ic{color:var(--gold)}

/* ---------- 详情弹层 ---------- */
.modal-bg{position:fixed;inset:0;background:rgba(3,5,12,.78);backdrop-filter:blur(6px);z-index:80;
  display:none;align-items:center;justify-content:center;padding:20px}
.modal-bg.open{display:flex}
.modal{max-width:680px;width:100%;max-height:86vh;overflow:auto;background:var(--panel-solid);
  border:1px solid var(--line);border-radius:20px;padding:26px;box-shadow:var(--shadow);position:relative}
.modal h3{font-family:var(--serif);font-size:26px;letter-spacing:1px;margin-bottom:4px}
.modal .latin{color:var(--gold);font-style:italic;letter-spacing:1px;margin-bottom:16px;font-size:14px}
.modal .x{position:absolute;right:16px;top:14px;width:34px;height:34px;border-radius:50%;border:1px solid var(--line-soft);
  background:rgba(255,255,255,.04);color:var(--ink);cursor:pointer;font-size:18px;line-height:1}
.modal .x:hover{border-color:var(--cinnabar);color:var(--cinnabar)}
.kv{display:grid;grid-template-columns:96px 1fr;gap:8px 14px;margin:14px 0;font-size:14px}
.kv dt{color:var(--gold);font-family:var(--serif);letter-spacing:1px}
.kv dd{color:var(--ink)}

/* 数据表 */
table.tbl{width:100%;border-collapse:collapse;font-size:13.5px;margin-top:10px}
table.tbl th,table.tbl td{padding:9px 10px;border-bottom:1px solid var(--line-soft);text-align:left}
table.tbl th{color:var(--gold);font-family:var(--serif);letter-spacing:1px;font-weight:600}
table.tbl tr:hover td{background:rgba(231,190,124,.05)}

/* ---------- 时间轴 ---------- */
.timeline{position:relative;margin-top:30px;padding-left:0}
.timeline::before{content:"";position:absolute;left:18px;top:6px;bottom:6px;width:2px;
  background:linear-gradient(var(--gold),var(--cinnabar));opacity:.5}
.tl-item{position:relative;padding:0 0 30px 56px}
.tl-item .dot{position:absolute;left:10px;top:4px;width:18px;height:18px;border-radius:50%;
  background:var(--bg);border:3px solid var(--gold);box-shadow:0 0 0 4px rgba(231,190,124,.12)}
.tl-item .yr{font-family:var(--serif);font-size:18px;color:var(--gold);letter-spacing:1px}
.tl-item h4{font-size:17px;margin:4px 0 6px}
.tl-item p{color:var(--muted);font-size:14px}

/* ---------- 科普文章 ---------- */
.article{max-width:820px;margin:0 auto}
.article h2{font-family:var(--serif);font-size:24px;letter-spacing:1px;margin:30px 0 10px;color:var(--ink)}
.article p{color:var(--muted);margin-bottom:14px;font-size:15px}
.article .fig{margin:22px 0;border:1px solid var(--line-soft);border-radius:14px;overflow:hidden;background:#05070f}
.article .fig img{border-radius:14px}
.article .cap{font-size:12.5px;color:var(--faint);padding:8px 12px;text-align:center}
.callout{border-left:3px solid var(--gold);background:rgba(231,190,124,.06);padding:14px 18px;border-radius:0 12px 12px 0;margin:18px 0;color:var(--ink);font-size:14.5px}

/* ---------- 页脚 ---------- */
footer.site{border-top:1px solid var(--line-soft);padding:30px 0 50px;margin-top:30px;
  color:var(--faint);font-size:13px;text-align:center}
footer.site .links{display:flex;gap:16px;justify-content:center;flex-wrap:wrap;margin-bottom:12px}
footer.site .links a{color:var(--muted)}
footer.site .links a:hover{color:var(--gold)}

/* ---------- 返回顶部 ---------- */
.totop{position:fixed;right:18px;bottom:20px;width:44px;height:44px;border-radius:50%;
  background:var(--panel-solid);border:1px solid var(--line);color:var(--gold);display:grid;place-items:center;
  cursor:pointer;opacity:0;pointer-events:none;transition:.3s;z-index:60;font-size:20px}
.totop.show{opacity:1;pointer-events:auto}

/* ---------- 中国风（宣纸·玄墨·朱砂）皮肤 ---------- */
body.skin-classic{
  color:#2b2118;background:#efe4cc;
}
body.skin-classic::before{
  background:
    radial-gradient(900px 600px at 10% -5%, rgba(176,58,46,.08), transparent 60%),
    radial-gradient(900px 700px at 95% 105%, rgba(60,90,140,.10), transparent 60%),
    linear-gradient(180deg,#f4ead2 0%, #ece0c4 100%);
}
body.skin-classic #starfield{opacity:.10}
body.skin-classic ::-webkit-scrollbar-thumb{background:linear-gradient(#b03a2e,#7d4a2e)}
body.skin-classic .nav a{color:#7a5c3a}
body.skin-classic .nav a.active{background:#b03a2e;color:#fdf3e0}
body.skin-classic .card,body.skin-classic .tile,body.skin-classic .modal{
  background:rgba(255,250,238,.82);border-color:rgba(176,58,46,.22);color:#2b2118}
body.skin-classic .card p,body.skin-classic .tile .desc,body.skin-classic .lead,body.skin-classic .muted{color:#5d4a35}
body.skin-classic .eyebrow,body.skin-classic .kicker,body.skin-classic .gold{color:#b03a2e}
body.skin-classic .h2,body.skin-classic h3,body.skin-classic h4,body.skin-classic .article h2{color:#3a2a1a}
body.skin-classic .chip{color:#7a5c3a;border-color:rgba(176,58,46,.25)}
body.skin-classic .chip.on{background:#b03a2e;color:#fdf3e0}
body.skin-classic .search{background:rgba(255,250,238,.85);border-color:rgba(176,58,46,.2)}
body.skin-classic .search input{color:#2b2118}
body.skin-classic .search .ic{color:#b03a2e}
body.skin-classic table.tbl th{color:#b03a2e}
body.skin-classic table.tbl th,body.skin-classic table.tbl td{border-color:rgba(176,58,46,.18)}
body.skin-classic .callout{border-left-color:#b03a2e;background:rgba(176,58,46,.06);color:#3a2a1a}
body.skin-classic .kv dt{color:#b03a2e}
body.skin-classic .btn{border-color:rgba(176,58,46,.3);color:#3a2a1a;background:rgba(255,250,238,.7)}
body.skin-classic .btn.primary{background:#b03a2e;color:#fdf3e0}
body.skin-classic .timeline::before{background:linear-gradient(#b03a2e,#7d4a2e)}
body.skin-classic .tl-item .dot{border-color:#b03a2e;background:#efe4cc}
body.skin-classic .tl-item .yr{color:#b03a2e}
body.skin-classic .totop{border-color:rgba(176,58,46,.3);color:#b03a2e;background:#f4ead2}

/* ---------- 响应式 ---------- */
@media(max-width:900px){
  .grid.cols-4{grid-template-columns:repeat(2,1fr)}
  .grid.cols-3{grid-template-columns:repeat(2,1fr)}
}
@media(max-width:620px){
  section{padding:40px 0}
  .grid.cols-2,.grid.cols-3,.grid.cols-4{grid-template-columns:1fr}
  .kv{grid-template-columns:84px 1fr}
  .site-row{flex-wrap:wrap;gap:8px}
  .brand{font-size:16px}
  .nav{width:100%;margin-left:0}
}

/* =========================================================
   阅读增强 · 顶部进度条 + 目录树
   ========================================================= */
.read-progress{position:fixed;top:0;left:0;right:0;height:3px;z-index:70;background:rgba(231,190,124,.10);pointer-events:none}
.read-progress__fill{height:100%;width:100%;transform:scaleX(0);transform-origin:0 50%;
  background:linear-gradient(90deg,var(--gold),var(--cinnabar));box-shadow:0 0 12px rgba(231,190,124,.6)}

.toc-rail{position:fixed;top:0;left:0;bottom:0;width:286px;z-index:45;
  padding:84px 14px 26px;overflow-y:auto;overflow-x:hidden;
  background:linear-gradient(180deg,rgba(12,17,48,.92),rgba(7,9,18,.92));
  border-right:1px solid var(--line-soft);backdrop-filter:blur(10px);
  transform:translateX(0);transition:transform .32s ease}
.toc-rail::-webkit-scrollbar{width:7px}
.toc-rail::-webkit-scrollbar-thumb{background:linear-gradient(var(--gold),var(--cinnabar));border-radius:6px}
.toc__title{font-family:var(--serif);font-size:15px;letter-spacing:3px;color:var(--gold);
  margin:0 8px 12px;padding-bottom:10px;border-bottom:1px solid var(--line-soft)}
.toc__list{list-style:none}
.toc__item{margin:1px 0}
.toc__item a{display:block;padding:7px 11px;border-radius:9px;color:var(--muted);font-size:13.5px;
  line-height:1.5;border-left:2px solid transparent;transition:.2s;cursor:pointer}
.toc__item a:hover{color:var(--ink);background:rgba(231,190,124,.07)}
.toc__item a.active{color:var(--gold);border-left-color:var(--gold);background:rgba(231,190,124,.12);font-weight:600}
.toc__item--h3 a{padding-left:25px;font-size:12.8px;color:var(--faint)}
.toc__item--h3 a.active{color:var(--gold)}

/* 移动端：抽屉 + 悬浮按钮 */
.toc-backdrop{position:fixed;inset:0;background:rgba(3,5,12,.6);z-index:44;opacity:0;visibility:hidden;transition:.3s}
.toc-toggle{position:fixed;left:16px;bottom:20px;z-index:46;display:none;align-items:center;gap:7px;
  padding:11px 16px;border-radius:999px;background:var(--panel-solid);border:1px solid var(--line);
  color:var(--gold);cursor:pointer;font-size:13.5px;box-shadow:var(--shadow);font-family:var(--sans)}
.toc-toggle span{line-height:1}
body.toc-open .toc-backdrop{opacity:1;visibility:visible}
body.toc-open .toc-rail{transform:translateX(0)}
body.toc-open .toc-toggle{display:none}

@media(min-width:1080px){
  body.has-toc > section:not(.hero),
  body.has-toc > footer.site{padding-left:306px}
  .toc-toggle{display:none!important}
}
@media(max-width:1079px){
  .toc-rail{transform:translateX(-100%)}
  .toc-toggle{display:inline-flex}
}

/* 浅色（宣纸）皮肤下的目录与进度条 */
body.skin-classic .toc-rail{background:linear-gradient(180deg,rgba(244,234,210,.96),rgba(236,224,196,.96));border-right-color:rgba(176,58,46,.2)}
body.skin-classic .toc__title{color:#b03a2e;border-color:rgba(176,58,46,.18)}
body.skin-classic .toc__item a{color:#7a5c3a}
body.skin-classic .toc__item a:hover{color:#3a2a1a;background:rgba(176,58,46,.06)}
body.skin-classic .toc__item a.active{color:#b03a2e;border-left-color:#b03a2e;background:rgba(176,58,46,.08)}
body.skin-classic .read-progress{background:rgba(176,58,46,.12)}
body.skin-classic .read-progress__fill{background:linear-gradient(90deg,#b03a2e,#7d4a2e)}
body.skin-classic .toc-toggle{background:#f4ead2;border-color:rgba(176,58,46,.3);color:#b03a2e}
body.skin-classic .toc-backdrop{background:rgba(43,33,24,.5)}