:root{
  --bg:#f7f5f0;
  --paper:#fffdf8;
  --ink:#2b2723;
  --muted:#6b6259;
  --line:#e3ddd1;
  --accent:#8a5a2b;
  --accent2:#b08442;
  --accent-soft:#f0e6d6;
  --listen:#3f6b4f;
  --explain:#8a5a2b;
  --live:#7a4a78;
  --maxw:820px;
  --sidebar:300px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;
  font-family:"Noto Serif TC","Songti TC","PingFang TC","Microsoft JhengHei",serif;
  background:var(--bg);
  color:var(--ink);
  line-height:1.95;
  font-size:18px;
  -webkit-font-smoothing:antialiased;
}
a{color:var(--accent);text-decoration:none}
a:hover{text-decoration:underline}

/* layout */
.layout{display:flex;min-height:100vh}
.sidebar{
  width:var(--sidebar);
  flex:0 0 var(--sidebar);
  background:#2b2723;
  color:#e8e1d5;
  position:sticky;
  top:0;
  height:100vh;
  overflow-y:auto;
  padding:0;
}
.sidebar .brand{
  padding:24px 22px 18px;
  border-bottom:1px solid #443d34;
  position:sticky;top:0;background:#2b2723;z-index:2;
}
.sidebar .brand a{color:#fff}
.sidebar .brand h1{font-size:19px;margin:0 0 4px;letter-spacing:.5px}
.sidebar .brand p{font-size:12.5px;color:#a99e8d;margin:0;line-height:1.5}
.nav-group{padding:14px 0 6px}
.nav-group .gh{
  font-size:12px;color:#c9a96a;text-transform:uppercase;letter-spacing:1px;
  padding:6px 22px;font-weight:700;
}
.sidebar nav a{
  display:block;color:#ddd5c7;padding:6px 22px 6px 26px;font-size:14.5px;
  border-left:3px solid transparent;line-height:1.45;
}
.sidebar nav a:hover{background:#3a332b;text-decoration:none;color:#fff}
.sidebar nav a.active{background:#3a332b;border-left-color:var(--accent2);color:#fff}
.sidebar nav a .vref{display:block;font-size:12px;color:#a99e8d}

/* content */
.content{flex:1;min-width:0;display:flex;justify-content:center;padding:0 28px 80px}
.page{width:100%;max-width:var(--maxw);padding-top:36px}
.crumb{font-size:13px;color:var(--muted);margin-bottom:18px}
.title-block{border-bottom:3px double var(--line);padding-bottom:18px;margin-bottom:28px}
.title-block .kicker{color:var(--accent2);font-size:14px;letter-spacing:2px;text-transform:uppercase}
.title-block h1{font-size:32px;margin:6px 0 4px;line-height:1.3}
.title-block .sub{color:var(--muted);font-size:16px;margin:0}

h2.section{
  font-size:23px;margin:42px 0 14px;padding:8px 0 8px 16px;
  border-left:6px solid var(--accent);
}
h2.listen{border-left-color:var(--listen);color:var(--listen)}
h2.explain{border-left-color:var(--explain);color:var(--explain)}
h2.live{border-left-color:var(--live);color:var(--live)}
h2.section .en{display:block;font-size:13px;letter-spacing:2px;color:var(--muted);font-weight:400;text-transform:uppercase}
h3{font-size:19px;margin:28px 0 10px;color:var(--accent)}
p{margin:0 0 16px}
.page blockquote{
  margin:18px 0;padding:14px 20px;background:var(--accent-soft);
  border-left:4px solid var(--accent2);border-radius:0 6px 6px 0;font-size:16.5px;color:#4a4036;
}
.passage{
  background:var(--paper);border:1px solid var(--line);border-radius:8px;
  padding:18px 22px;margin:18px 0 8px;font-size:16px;color:#544a3f;
}
.passage .lbl{font-size:12px;letter-spacing:1.5px;text-transform:uppercase;color:var(--accent2);font-weight:700;display:block;margin-bottom:6px}
.keypoints{background:#fff;border:1px solid var(--line);border-radius:8px;padding:6px 24px;margin:18px 0}
.keypoints li{margin:8px 0}
ul,ol{padding-left:1.4em}
li{margin:6px 0}
.note{font-size:14.5px;color:var(--muted);font-style:italic}
em.term{font-style:normal;color:var(--accent);font-weight:600}

/* pager */
.pager{display:flex;justify-content:space-between;gap:14px;margin-top:54px;border-top:1px solid var(--line);padding-top:22px}
.pager a{flex:1;padding:14px 18px;border:1px solid var(--line);border-radius:8px;background:#fff;font-size:14px}
.pager a:hover{border-color:var(--accent2);text-decoration:none}
.pager .nx{text-align:right}
.pager span{display:block;font-size:12px;color:var(--muted)}

/* index */
.hero{text-align:center;padding:60px 20px 30px}
.hero .kicker{color:var(--accent2);letter-spacing:3px;text-transform:uppercase;font-size:14px}
.hero h1{font-size:40px;margin:10px 0 8px}
.hero .by{color:var(--muted);font-size:16px}
.hero .lead{max-width:680px;margin:22px auto 0;color:#4a4036;font-size:17px}
.toc-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(150px,1fr));gap:10px;margin:18px 0}
.toc-grid a{background:#fff;border:1px solid var(--line);border-radius:8px;padding:12px 14px;font-size:14.5px}
.toc-grid a:hover{border-color:var(--accent2);text-decoration:none;background:var(--accent-soft)}
.toc-grid a b{display:block;color:var(--ink);font-size:15px}
.toc-grid a span{color:var(--muted);font-size:12.5px}
.book-head{margin:38px 0 6px;font-size:24px;color:var(--accent);border-bottom:2px solid var(--line);padding-bottom:8px}

/* mobile */
.menu-btn{display:none}
@media(max-width:880px){
  .sidebar{position:fixed;left:-100%;z-index:50;transition:left .25s;width:84%;max-width:320px}
  .sidebar.open{left:0;box-shadow:0 0 40px rgba(0,0,0,.4)}
  .menu-btn{display:flex;position:fixed;top:14px;left:14px;z-index:60;
    background:#2b2723;color:#fff;border:none;border-radius:8px;padding:10px 14px;font-size:15px;cursor:pointer;align-items:center;gap:6px}
  .content{padding:0 16px 60px}
  .page{padding-top:64px}
  .overlay{display:none;position:fixed;inset:0;background:rgba(0,0,0,.45);z-index:40}
  .overlay.show{display:block}
  body{font-size:17px}
  .hero h1{font-size:30px}
}