:root{
  --bg:#faf7f0;
  --panel:#fffdf8;
  --ink:#1f2a37;
  --muted:#6b6256;
  --navy:#1b2a4a;
  --gold:#b8893a;
  --line:#e7e0d3;
  --en-bar:#1b2a4a;
  --zh-bar:#b8893a;
  --shadow:0 1px 3px rgba(27,42,74,.08),0 8px 24px rgba(27,42,74,.06);
}
*{box-sizing:border-box}
html,body{margin:0;padding:0}
body{
  background:var(--bg);
  color:var(--ink);
  font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Hiragino Sans GB","Microsoft YaHei",Roboto,Helvetica,Arial,sans-serif;
  line-height:1.75;
  -webkit-font-smoothing:antialiased;
}
a{color:var(--navy);text-decoration:none}
a:hover{text-decoration:underline}
.wrap{max-width:1140px;margin:0 auto;padding:0 20px}

/* ---------- Top bar ---------- */
.topbar{
  position:sticky;top:0;z-index:50;
  background:rgba(255,253,248,.92);
  backdrop-filter:blur(8px);
  border-bottom:1px solid var(--line);
}
.topbar .wrap{display:flex;align-items:center;gap:14px;height:60px}
.brand{display:flex;align-items:center;gap:10px;font-weight:700;color:var(--navy);font-size:18px}
.brand .logo{width:30px;height:30px;border-radius:7px;background:linear-gradient(135deg,var(--navy),var(--gold));color:#fff;display:flex;align-items:center;justify-content:center;font-weight:800;font-size:15px}
.brand small{font-weight:500;color:var(--muted);font-size:12px;display:block;margin-top:-4px}
.topbar .spacer{flex:1}
.home-link{font-size:14px;color:var(--muted)}

/* ---------- Hero ---------- */
.hero{padding:48px 0 28px;text-align:center}
.hero h1{font-size:34px;margin:0 0 10px;color:var(--navy);letter-spacing:.5px}
.hero p{color:var(--muted);margin:6px auto;max-width:680px;font-size:15px}
.hero .stats{display:flex;gap:26px;justify-content:center;margin-top:18px;flex-wrap:wrap}
.hero .stats div{text-align:center}
.hero .stats b{display:block;font-size:24px;color:var(--gold)}
.hero .stats span{font-size:12px;color:var(--muted)}

/* ---------- Index grid ---------- */
.toolbar{display:flex;gap:12px;align-items:center;margin:10px 0 22px;flex-wrap:wrap}
.search{flex:1;min-width:200px;position:relative}
.search input{width:100%;padding:11px 14px 11px 38px;border:1px solid var(--line);border-radius:10px;background:var(--panel);font-size:15px;color:var(--ink)}
.search input:focus{outline:none;border-color:var(--gold)}
.search svg{position:absolute;left:12px;top:50%;transform:translateY(-50%);opacity:.5}
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(250px,1fr));gap:16px;padding-bottom:50px}
.card{
  background:var(--panel);border:1px solid var(--line);border-radius:14px;padding:18px 18px 16px;
  box-shadow:var(--shadow);transition:transform .15s ease,box-shadow .15s ease;display:flex;flex-direction:column;gap:8px}
.card:hover{transform:translateY(-3px);box-shadow:0 10px 30px rgba(27,42,74,.12)}
.card .yr{font-size:26px;font-weight:800;color:var(--navy);line-height:1}
.card .ttl{font-size:15px;font-weight:600;color:var(--ink)}
.card .meta{font-size:12px;color:var(--muted);display:flex;flex-direction:column;gap:2px}
.card .meta b{color:var(--gold);font-weight:600}
.card .badge{margin-top:auto;align-self:flex-start;font-size:11px;color:var(--gold);border:1px solid var(--gold);border-radius:20px;padding:2px 10px;opacity:.85}
.card.special{border-color:#d9c39a}

/* ---------- Letter page ---------- */
.letter-head{padding:30px 0 12px;border-bottom:1px solid var(--line);margin-bottom:8px}
.letter-head .breadcrumb{font-size:13px;color:var(--muted);margin-bottom:10px}
.letter-head h1{font-size:28px;color:var(--navy);margin:0 0 6px}
.letter-head .sub{color:var(--muted);font-size:14px;display:flex;gap:16px;flex-wrap:wrap}
.letter-head .sub b{color:var(--gold)}

/* control bar */
.controls{position:sticky;top:60px;z-index:40;background:rgba(250,247,240,.95);backdrop-filter:blur(6px);
  border-bottom:1px solid var(--line);padding:10px 0;margin-bottom:14px}
.controls .wrap{display:flex;align-items:center;gap:10px;flex-wrap:wrap}
.seg{display:inline-flex;border:1px solid var(--line);border-radius:10px;overflow:hidden;background:var(--panel)}
.seg button{border:none;background:transparent;padding:8px 14px;font-size:14px;cursor:pointer;color:var(--muted)}
.seg button.active{background:var(--navy);color:#fff}
.tts-group{display:flex;gap:8px;flex-wrap:wrap;margin-left:auto}
.btn{border:1px solid var(--line);background:var(--panel);border-radius:10px;padding:8px 14px;font-size:14px;cursor:pointer;color:var(--ink);display:inline-flex;align-items:center;gap:6px;transition:background .15s}
.btn:hover{background:#f1ead9}
.btn.primary{background:var(--navy);color:#fff;border-color:var(--navy)}
.btn.primary:hover{background:#14203a}
.btn.gold{background:var(--gold);color:#fff;border-color:var(--gold)}
.btn.gold:hover{background:#a3782f}
.btn:disabled{opacity:.45;cursor:not-allowed}
.btn .dot{width:8px;height:8px;border-radius:50%;background:currentColor;opacity:.6}

/* content blocks */
.blocks{padding-bottom:60px}
.b-heading{font-size:20px;font-weight:700;color:var(--navy);margin:30px 0 12px;padding-left:12px;border-left:4px solid var(--gold)}
.b-hr{height:1px;background:var(--line);margin:22px 0;border:0}
.b-pair{display:grid;grid-template-columns:1fr 1fr;gap:0;border:1px solid var(--line);border-radius:12px;overflow:hidden;margin:10px 0;background:var(--panel)}
.b-pair .col{padding:14px 18px;position:relative}
.b-pair .col.en{border-right:1px solid var(--line);border-left:4px solid var(--en-bar)}
.b-pair .col.zh{border-left:4px solid var(--zh-bar)}
.b-enonly{background:var(--panel);border:1px solid var(--line);border-left:4px solid var(--en-bar);border-radius:12px;padding:14px 18px;margin:10px 0}
.b-zhonly{background:var(--panel);border:1px solid var(--line);border-left:4px solid var(--zh-bar);border-radius:12px;padding:14px 18px;margin:10px 0}
.mode-zh .b-pair,.mode-en .b-pair{display:block}
.mode-zh .b-pair .col.en,.mode-en .b-pair .col.zh{display:none}
.mode-zh .b-pair .col.zh{border-left:4px solid var(--zh-bar)}
.mode-en .b-pair .col.en{border-left:4px solid var(--en-bar);border-right:none}
.mode-zh .b-enonly{display:none}
.mode-en .b-zhonly{display:none}
.read-btn{position:absolute;top:8px;right:10px;border:1px solid var(--line);background:#fff;border-radius:50%;width:30px;height:30px;cursor:pointer;opacity:0;transition:opacity .15s;font-size:13px;display:flex;align-items:center;justify-content:center;color:var(--muted)}
.col:hover .read-btn,.b-enonly:hover .read-btn,.b-zhonly:hover .read-btn{opacity:1}
.read-btn.playing{opacity:1;color:var(--gold);border-color:var(--gold)}

/* progress pill */
.progress{font-size:12px;color:var(--muted);min-width:90px;text-align:right}
.progress .bar{height:4px;background:var(--line);border-radius:3px;margin-top:4px;overflow:hidden}
.progress .bar i{display:block;height:100%;width:0;background:var(--gold);transition:width .2s}

footer{border-top:1px solid var(--line);padding:26px 0;color:var(--muted);font-size:13px;text-align:center;line-height:1.9}
footer a{color:var(--navy)}

@media(max-width:720px){
  .b-pair{grid-template-columns:1fr}
  .b-pair .col.en{border-right:none;border-bottom:1px solid var(--line)}
  .hero h1{font-size:26px}
  .read-btn{opacity:1}
  .controls .wrap{gap:6px}
  .tts-group{margin-left:0;width:100%}
}

/* 文章页「视频」按钮 */
#btn-video{text-decoration:none}
#btn-video:hover{text-decoration:none}

/* ---------- Tabs (index) ---------- */
.tabs{display:inline-flex;border:1px solid var(--line);border-radius:12px;overflow:hidden;background:var(--panel);margin:18px 0 6px}
.tabs .tab{border:none;background:transparent;padding:10px 20px;font-size:15px;cursor:pointer;color:var(--muted);font-weight:600;font-family:inherit}
.tabs .tab.active{background:var(--navy);color:#fff}
.tab-hint{color:var(--muted);font-size:14px;margin:0 0 14px}
.book-card .badge{background:var(--gold);color:#fff;border:none;opacity:1}

/* ---------- Book detail (book.html) ---------- */
.intro{color:var(--muted);font-size:14px;line-height:1.95;margin:12px 0 0;max-width:780px}
.bpoints{padding-bottom:60px;display:flex;flex-direction:column;gap:14px}
.book-point{position:relative;display:flex;gap:14px;background:var(--panel);border:1px solid var(--line);border-left:4px solid var(--gold);border-radius:12px;padding:16px 52px 16px 18px;box-shadow:var(--shadow)}
.book-point .bp-no{flex:0 0 30px;height:30px;border-radius:50%;background:var(--navy);color:#fff;display:flex;align-items:center;justify-content:center;font-weight:700;font-size:14px}
.book-point .bp-body{flex:1;min-width:0}
.bp-title{font-weight:700;color:var(--navy);font-size:16px;margin-bottom:5px;line-height:1.5}
.bp-text{color:var(--ink);font-size:15px;line-height:1.85}
.book-point .read-btn{top:14px;right:12px}

/* ---------- Bilingual book points (20260813b) ---------- */
.book-point{padding:16px 112px 16px 18px}
.intro-zh{font-size:15px;line-height:1.95;color:var(--ink);margin-bottom:8px}
.intro-en{font-size:13.5px;line-height:1.8;color:var(--muted);margin-top:2px}
.bp-title-en{font-size:13px;font-weight:400;color:var(--muted);margin-left:6px}
.bp-text.en{color:var(--muted);font-size:14px;line-height:1.8;margin-top:7px;border-top:1px dashed var(--line);padding-top:7px}
.bp-reads{position:absolute;top:14px;right:12px;display:flex;flex-direction:column;gap:6px}
.bp-reads .read-btn{position:static;top:auto;right:auto;margin:0}
.read-btn.en{background:#eef2f7;color:#1f3a5f;font-size:11px;font-weight:700;padding:4px 9px;border-radius:6px}
.muted-en{color:var(--muted);font-size:12px;font-weight:400}