/* 从洞窟到画廊 · 共用样式
   Layout: 单栏长文（约 42rem）+ 可外扩的大图；宽屏左侧固定目录。颜色以颜料命名。 */
:root{
  --paper:#F3F4F1;      /* 铅白底 */
  --paper-2:#E7E9E3;
  --ink:#1B1D1C;        /* 墨 */
  --ink-2:#565C58;
  --rule:#D2D5CE;
  --ultramarine:#2B3F93;/* 群青：来自青金石 */
  --ochre:#9E5F1A;      /* 赭石：最古老的颜料 */
  --cinnabar:#A8322A;   /* 朱砂：印章 */
  --hot-bg:#2B3F93; --hot-fg:#FFFFFF;
  --shadow:0 1px 2px rgba(20,24,22,.08),0 8px 24px rgba(20,24,22,.08);
  --f-display:"ZCOOL XiaoWei","Noto Serif SC","Songti SC","SimSun",serif;
  --f-body:"Noto Serif SC","Songti SC","SimSun",serif;
  --f-ui:"PingFang SC","Microsoft YaHei","Noto Sans SC",system-ui,sans-serif;
  --f-latin:"Cormorant Garamond","Georgia",serif;
  --measure:42rem; --wide:68rem;
}
@media (prefers-color-scheme: dark){:root:not([data-theme="light"]){
  --paper:#131514; --paper-2:#1C1F1D; --ink:#E6E7E2; --ink-2:#A2A8A3; --rule:#2D312E;
  --ultramarine:#9AAEF5; --ochre:#DDA45E; --cinnabar:#E57A6F; --hot-bg:#9AAEF5; --hot-fg:#0E1430;
  --shadow:0 1px 2px rgba(0,0,0,.4),0 8px 24px rgba(0,0,0,.35); color-scheme:dark}}
:root[data-theme="dark"]{
  --paper:#131514; --paper-2:#1C1F1D; --ink:#E6E7E2; --ink-2:#A2A8A3; --rule:#2D312E;
  --ultramarine:#9AAEF5; --ochre:#DDA45E; --cinnabar:#E57A6F; --hot-bg:#9AAEF5; --hot-fg:#0E1430;
  --shadow:0 1px 2px rgba(0,0,0,.4),0 8px 24px rgba(0,0,0,.35); color-scheme:dark}

*{box-sizing:border-box}
html{scroll-behavior:smooth}
@media (prefers-reduced-motion:reduce){html{scroll-behavior:auto}*{transition:none!important;animation:none!important}}
body{background:var(--paper);color:var(--ink);font-family:var(--f-body);font-size:17px;line-height:1.95;
  padding-inline:16px;padding-block:0 4rem;-webkit-font-smoothing:antialiased}
a{color:var(--ultramarine);text-underline-offset:3px;text-decoration-thickness:1px}
a:focus-visible,button:focus-visible,.hot:focus-visible{outline:2px solid var(--ochre);outline-offset:2px}
img{max-width:100%;display:block}
.latin{font-family:var(--f-latin);font-style:italic;font-size:1.08em;letter-spacing:.01em}

/* ---------- 版式骨架 ---------- */
.page{max-width:var(--wide);margin-inline:auto;display:grid;grid-template-columns:minmax(0,1fr);gap:0}
@media (min-width:1180px){.page{max-width:calc(var(--wide) + 15rem);grid-template-columns:13rem minmax(0,1fr);gap:2rem}}
.toc{display:none}
@media (min-width:1180px){
  .toc{display:block;position:sticky;top:calc(env(safe-area-inset-top,0px) + 1.5rem);align-self:start;
    max-height:calc(100vh - 3rem);overflow:auto;padding-top:7.5rem;font-family:var(--f-ui);font-size:13px;line-height:1.6}
  .toc b{display:block;font-size:11px;letter-spacing:.14em;color:var(--ink-2);font-weight:600;margin-bottom:.6rem}
  .toc ol{list-style:none;margin:0;padding:0;display:grid;gap:.15rem}
  .toc a{color:var(--ink-2);text-decoration:none;display:block;padding:.2rem .6rem;border-left:2px solid var(--rule)}
  .toc a:hover{color:var(--ink)}
  .toc a.on{color:var(--ultramarine);border-left-color:var(--ultramarine)}
  .toc .sub a{padding-left:1.4rem;font-size:12px}
}
main{min-width:0}
.col{max-width:var(--measure);margin-inline:auto}
.wide{max-width:var(--wide);margin-inline:auto}

/* ---------- 顶部 ---------- */
.course{font-family:var(--f-ui);font-size:12px;letter-spacing:.16em;color:var(--ink-2);display:flex;flex-wrap:wrap;gap:.4rem 1rem;
  justify-content:space-between;padding-block:1.25rem;border-bottom:1px solid var(--rule)}
.course a{color:var(--ink-2);text-decoration:none}
.course a:hover{color:var(--ink)}
.hero{padding-block:3rem 2rem}
.hero .no{font-family:var(--f-ui);font-size:13px;letter-spacing:.2em;color:var(--ochre);font-weight:600}
.hero h1{font-family:var(--f-display);font-weight:400;font-size:clamp(2.4rem,6vw,4.2rem);line-height:1.15;margin:.6rem 0 1rem;text-wrap:balance}
.hero .dek{font-size:1.15rem;color:var(--ink-2);max-width:36rem;margin:0}
.hero .span{font-family:var(--f-ui);font-size:13px;color:var(--ink-2);margin-top:1.2rem;font-variant-numeric:tabular-nums}
.hero-img{margin-block:0 1rem}
.hero-img img{width:100%;max-height:78vh;object-fit:cover;cursor:zoom-in}
.hero-img figcaption{font-family:var(--f-ui);font-size:12.5px;color:var(--ink-2);margin-top:.5rem;line-height:1.6}

/* ---------- 正文 ---------- */
section{padding-top:2.5rem}
h2{font-family:var(--f-display);font-weight:400;font-size:clamp(1.7rem,3.6vw,2.3rem);line-height:1.3;margin:2.5rem 0 1rem;text-wrap:balance}
h2 .k{display:block;font-family:var(--f-ui);font-size:12px;letter-spacing:.18em;color:var(--ochre);font-weight:600;margin-bottom:.35rem}
h3{font-family:var(--f-display);font-weight:400;font-size:1.45rem;line-height:1.4;margin:2.2rem 0 .6rem;text-wrap:balance}
h4{font-family:var(--f-ui);font-size:13px;letter-spacing:.14em;color:var(--ultramarine);font-weight:700;margin:1.8rem 0 .4rem}
p{margin:0 0 1.1rem}
strong{font-weight:700}
.ref{font-family:var(--f-ui);font-size:11px;vertical-align:super;text-decoration:none;margin-left:1px}
.term{border-bottom:1px dotted var(--ochre);cursor:help}
hr.break{border:0;border-top:1px solid var(--rule);margin:3rem auto;max-width:var(--measure)}
.lead::first-letter{font-family:var(--f-display);float:left;font-size:3.4em;line-height:1;margin:.12em .12em 0 0;color:var(--ochre)}

/* 旁注框 */
.note{background:var(--paper-2);padding:1rem 1.2rem;margin:1.5rem 0;font-size:15.5px;line-height:1.85}
.note b.t{display:block;font-family:var(--f-ui);font-size:12px;letter-spacing:.14em;color:var(--ochre);margin-bottom:.3rem}
.note p:last-child{margin-bottom:0}
.vs{display:grid;grid-template-columns:repeat(auto-fit,minmax(15rem,1fr));gap:1rem;margin:1.5rem 0}
.vs>div{border-top:3px solid var(--ultramarine);padding-top:.7rem;min-width:0}
.vs>div:nth-child(2){border-top-color:var(--ochre)}
.vs b.t{font-family:var(--f-ui);font-size:12px;letter-spacing:.14em;display:block;margin-bottom:.3rem}

/* ---------- 图 ---------- */
figure{margin:2rem 0}
figure img{cursor:zoom-in;background:var(--paper-2)}
figcaption{font-family:var(--f-ui);font-size:13px;line-height:1.65;color:var(--ink-2);margin-top:.6rem}
figcaption b{color:var(--ink);font-weight:600}
.pair{display:grid;grid-template-columns:repeat(auto-fit,minmax(14rem,1fr));gap:1rem;align-items:start}
.pair figure{margin:0}
.trio{display:grid;grid-template-columns:repeat(auto-fit,minmax(11rem,1fr));gap:1rem;align-items:start}
.trio figure{margin:0}
.tall img{max-height:88vh;width:auto;margin-inline:auto}

/* 热点图 */
.hotfig{position:relative;margin:0}
.hotfig .frame{position:relative;width:fit-content;max-width:100%;margin-inline:auto}
.hotfig .frame img{max-height:88vh;width:auto;max-width:100%}
.hot{position:absolute;left:var(--x);top:var(--y);transform:translate(-50%,-50%);width:28px;height:28px;border-radius:50%;
  background:var(--hot-bg);color:var(--hot-fg);font:700 13px/28px var(--f-ui);text-align:center;text-decoration:none;
  box-shadow:0 0 0 3px rgba(255,255,255,.75),0 2px 8px rgba(0,0,0,.4);transition:transform .15s}
.hot:hover{transform:translate(-50%,-50%) scale(1.15)}

/* 展签 */
.work{margin:3.5rem 0 1rem;padding-top:2rem;border-top:1px solid var(--rule)}
.work>h3{margin-top:0;font-size:1.75rem}
.work .orig{font-family:var(--f-latin);font-style:italic;color:var(--ink-2);font-size:1.15rem;margin:-.4rem 0 1rem}
.label{font-family:var(--f-ui);font-size:13px;line-height:1.6;display:grid;grid-template-columns:auto minmax(0,1fr);gap:.25rem 1rem;
  border-left:3px solid var(--ochre);padding:.2rem 0 .2rem 1rem;margin:1rem 0 1.5rem;max-width:var(--measure);margin-inline:auto}
.label dt{color:var(--ink-2);letter-spacing:.08em}
.label dd{margin:0;font-variant-numeric:tabular-nums}

/* 局部细读 */
.details{display:grid;grid-template-columns:repeat(auto-fit,minmax(17rem,1fr));gap:1.5rem;margin:1.5rem 0 2rem}
.detail{min-width:0;scroll-margin-top:2rem}
.detail img{width:100%;aspect-ratio:4/3;object-fit:cover;cursor:zoom-in}
.detail .h{display:flex;gap:.6rem;align-items:baseline;margin:.7rem 0 .2rem}
.detail .n{flex:none;width:22px;height:22px;border-radius:50%;background:var(--hot-bg);color:var(--hot-fg);font:700 12px/22px var(--f-ui);text-align:center}
.detail .h b{font-family:var(--f-ui);font-size:15px}
.detail p{font-size:15.5px;line-height:1.85;margin:0}
.detail:target img{outline:3px solid var(--ochre);outline-offset:2px}

/* 手卷横向浏览 */
.scroller{overflow-x:auto;background:var(--paper-2);padding:.75rem;margin:1rem 0 .3rem;scrollbar-width:thin}
.scroller img{max-width:none;height:auto;cursor:zoom-in}
.scroller.h180 img{height:180px;width:auto}
.scroller.h420 img{height:min(420px,60vh);width:auto}
.hint{font-family:var(--f-ui);font-size:12px;color:var(--ink-2)}

/* 时间轴 */
.tl{overflow-x:auto;margin:1.5rem 0}
.tl svg{display:block;min-width:640px;width:100%;height:auto}
.tl text{font-family:var(--f-ui);fill:var(--ink)}
.tl .sub{fill:var(--ink-2)}

/* 表格 */
.tbl{overflow-x:auto;margin:1.5rem 0}
table{border-collapse:collapse;width:100%;font-family:var(--f-ui);font-size:14px;line-height:1.6;min-width:34rem}
th,td{text-align:left;vertical-align:top;padding:.6rem .7rem;border-bottom:1px solid var(--rule)}
th{font-size:12px;letter-spacing:.1em;color:var(--ink-2);font-weight:600}

/* 自测 */
.quiz{list-style:none;padding:0;margin:1rem 0;display:grid;gap:.8rem;counter-reset:q}
.quiz li{counter-increment:q;background:var(--paper-2);padding:.9rem 1.1rem;font-size:15.5px}
.quiz li::before{content:"问 " counter(q);display:block;font-family:var(--f-ui);font-size:12px;letter-spacing:.14em;color:var(--ochre);font-weight:700}
.quiz details{margin-top:.4rem}
.quiz summary{cursor:pointer;font-family:var(--f-ui);font-size:13px;color:var(--ultramarine)}

/* 来源 */
.sources{font-family:var(--f-ui);font-size:13.5px;line-height:1.7;padding-left:1.6rem}
.sources li{margin-bottom:.45rem;scroll-margin-top:2rem}
.sources li:target{background:var(--paper-2)}
.sources .src{color:var(--ink-2)}
.credits{font-family:var(--f-ui);font-size:12px;line-height:1.7;color:var(--ink-2)}

/* 章节导航 */
.chapnav{display:grid;grid-template-columns:repeat(auto-fit,minmax(14rem,1fr));gap:1rem;margin-top:3rem;font-family:var(--f-ui)}
.chapnav a{display:block;border:1px solid var(--rule);padding:1rem 1.2rem;text-decoration:none;color:var(--ink)}
.chapnav a:hover{border-color:var(--ultramarine)}
.chapnav small{display:block;color:var(--ink-2);font-size:12px;letter-spacing:.12em}
.chapnav .next{text-align:right}
.chapnav span.off{display:block;border:1px dashed var(--rule);padding:1rem 1.2rem;color:var(--ink-2)}

/* 看大图 */
.lb{position:fixed;inset:0;background:rgba(8,9,9,.94);z-index:50;display:flex;flex-direction:column}
.lb[hidden]{display:none!important}
.lb .bar{display:flex;gap:1rem;align-items:center;justify-content:space-between;padding:calc(env(safe-area-inset-top,0px) + .6rem) 1rem .6rem;color:#ddd;font:13px/1.5 var(--f-ui)}
.lb .bar span{min-width:0;overflow:hidden;text-overflow:ellipsis;white-space:nowrap}
.lb button{background:none;border:1px solid #666;color:#eee;font:13px var(--f-ui);padding:.3rem .8rem;cursor:pointer;flex:none}
.lb .stage{flex:1;overflow:auto;display:flex;min-height:0}
.lb .stage img{margin:auto;max-width:100%;max-height:100%;object-fit:contain;cursor:zoom-in;background:none}
.lb .stage.zoom img{max-width:none;max-height:none;cursor:zoom-out}

/* 打印 / 导出 PDF */
@media print{
  @page{size:A4;margin:14mm 12mm}
  body{font-size:11.5pt;line-height:1.8;padding:0}
  .toc,.chapnav,.lb,.hint+.scroller{display:none!important}
  .page{display:block;max-width:none}
  .hero{padding-block:0 1rem}
  .hero-img img{max-height:none;object-fit:contain}
  figure,.detail,.label,.note,.vs>div,.quiz li{break-inside:avoid}
  h2,h3,h4{break-after:avoid}
  .hotfig .frame img,.tall img{max-height:240mm}
  .scroller{overflow:visible;padding:0;background:none}
  .scroller img,.scroller.h180 img,.scroller.h420 img{width:100%!important;height:auto!important;max-width:100%}
  .tl{overflow:visible}.tl svg{min-width:0}
  .tbl{overflow:visible}table{min-width:0}
  .quiz details{display:block}
  .quiz details>*{display:block}
  a{color:inherit;text-decoration:none}
  .sources a{text-decoration:underline}
}