:root{
  --bg:#0f1115; --fg:#e7e7ec; --muted:#9aa3b2; --card:#151a24; --border:#273248; --brand:#6ea8fe;
  --ff:system-ui,-apple-system,"Segoe UI",Roboto,Arial;
}
:root[data-theme="light"]{ --bg:#ffffff; --fg:#161821; --muted:#6b7280; --card:#f4f6f9; --border:#dbe1ea; --brand:#0ea5e9; }

*{box-sizing:border-box}
html,body{margin:0;padding:0;background:var(--bg);color:var(--fg);font:400 16px/1.6 var(--ff)}
a{color:var(--brand);text-decoration:none}
a:hover{opacity:.9}
.container{max-width:1140px;margin:0 auto;padding:16px}

/* Header */
.site-header{border-bottom:1px solid var(--border);background:var(--card);position:sticky;top:0;z-index:10}
.header-inner{display:flex;gap:12px;align-items:center;justify-content:space-between}
.logo{font-weight:800}
.topnav{display:flex;gap:8px;align-items:center}
.search{min-width:260px;padding:8px 10px;border-radius:10px;border:1px solid var(--border);background:transparent;color:var(--fg)}
.icon-btn,.btn{display:inline-flex;gap:6px;align-items:center;padding:8px 12px;border:1px solid var(--border);border-radius:10px;background:transparent;color:var(--fg);cursor:pointer}

/* Layout */
.site-main{min-height:60vh}
.home-grid{display:grid;grid-template-columns:1fr 360px;gap:16px}
.two-cols{display:grid;grid-template-columns:1fr 320px;gap:16px}
.home-main,.home-sidebar{display:grid;gap:12px}
.card{background:var(--card);border:1px solid var(--border);border-radius:12px;padding:12px}
.muted{color:var(--muted)}
.split{width:1px;height:24px;background:var(--border);margin:0 6px;display:inline-block}

/* Books */
.grid-cards{display:grid;grid-template-columns:repeat(auto-fill,minmax(140px,1fr));gap:12px}
.book-card{display:grid;gap:8px}
.book-card .thumb img{width:100%;aspect-ratio:3/4;object-fit:cover;border-radius:10px;border:1px solid var(--border);background:#222}
.center{text-align:center}
.list{display:grid;gap:8px}
.li{display:grid;grid-template-columns:32px 1fr auto;gap:8px;align-items:center;background:var(--card);border:1px solid var(--border);border-radius:12px;padding:8px 10px}
.li.book{grid-template-columns:52px 1fr auto}
.cover{width:52px;height:74px;object-fit:cover;border-radius:8px;border:1px solid var(--border)}
.ph-cover{width:52px;height:74px;border-radius:8px;border:1px dashed var(--border);display:grid;place-items:center;color:var(--muted)}
.ph-cover-lg{width:132px;height:176px;border-radius:12px;border:1px dashed var(--border);display:grid;place-items:center;color:var(--muted)}
.cover-lg-wrap{width:132px}
.rank{width:28px;height:28px;display:grid;place-items:center;border:1px solid var(--border);border-radius:50%}
.tag{display:inline-block;border:1px solid var(--border);padding:2px 8px;border-radius:999px;color:var(--muted);margin-right:6px}

/* BXH */
.rk-head{display:flex;justify-content:space-between;align-items:center}
.tabs{display:inline-flex;gap:6px}
.tabs .tab-btn{border:none;background:transparent;border-bottom:2px solid transparent;color:var(--muted);padding:6px 8px;cursor:pointer}
.tabs .tab-btn.active{color:var(--fg);border-color:var(--brand)}
.rk-item{display:flex;gap:10px;padding:8px;border-bottom:1px dashed var(--border);align-items:center}
.rk-item img{width:56px;height:80px;object-fit:cover;border-radius:6px;background:#222}

/* Reader */
.toolbar{display:flex;gap:8px;flex-wrap:wrap;background:var(--card);border:1px solid var(--border);padding:8px;border-radius:12px;margin:8px 0}
.toolbar label{display:flex;gap:6px;align-items:center;background:rgba(255,255,255,.03);padding:4px 8px;border-radius:8px}
.chapter-title{margin:8px 0 4px}
.reader.two-cols{display:grid;grid-template-columns:1fr 1fr;gap:16px}
.reader .col{background:var(--card);border:1px solid var(--border);border-radius:12px;padding:14px 16px}
.reader .col h4{margin:2px 0 10px;color:var(--muted);font-weight:600}
.reader .reader-content{font:400 18px/1.6 var(--ff);letter-spacing:0}
.reader .reader-content p{margin:0 0 12px}

/* Song ngữ & ngôn ngữ đơn (chỉ vùng đọc) */
body.bilingual .reader.two-cols{grid-template-columns:1fr 1fr}
body:not(.bilingual) .reader.two-cols{grid-template-columns:1fr}
body:not(.bilingual).lang-vi #nb-en{display:none}
body:not(.bilingual).lang-en #nb-vi{display:none}

/* Focus mode */
.focus .site-header,.focus .site-footer{display:none!important}
.focus .container{max-width:900px}

/* Footer */
.site-footer{margin:16px 0}

/* Responsive */
@media (max-width:1024px){ .home-grid,.two-cols{grid-template-columns:1fr} }