*,*::before,*::after{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}

::-webkit-scrollbar{width:6px}
::-webkit-scrollbar-track{background:transparent}
::-webkit-scrollbar-thumb{background:var(--border);border-radius:4px}
::-webkit-scrollbar-thumb:hover{background:var(--accent)}

:root {
  --bg: #faf7f2;
  --bg-card: #fff;
  --bg-nav: rgba(250,247,242,0.82);
  --text: #1a1a1a;
  --text-secondary: #666;
  --text-muted: #888;
  --text-dim: #999;
  --border: #e5e0d8;
  --accent: #d97706;
  --accent-hover: #b45309;
  --accent-light: #fef3c7;
  --accent-border: #fde68a;
  --code-bg: #fff;
  --code-lang-bg: #f0ede8;
  --layer-l1-bg: #f0fdf6;
  --layer-l2-bg: #f0f7ff;
  --layer-l3-bg: #fffbf5;
  --layer-l4-bg: #faf8ff;
  --layer-l5-bg: #fff8f8;
  --hero-gradient: linear-gradient(180deg,#fef9e7 0%,#faf7f2 100%);
  --table-hover: #fef9e7;
  --overlay-bg: rgba(0,0,0,0.4);
  --shadow: 0 1px 3px rgba(0,0,0,0.04),0 1px 2px rgba(0,0,0,0.06);
  --shadow-hover: 0 8px 24px rgba(234,179,8,0.12),0 2px 8px rgba(0,0,0,0.06);
  --math-bg: #f0f7ff;
  --math-border: #bfdbfe;
  --note-bg: #fef3c7;
  --note-border: #fde68a;
  --note-color: #92400e;
  --progress-gradient: linear-gradient(90deg,#fde68a,#fbbf24,#f59e0b,#fbbf24);
  --hero-pattern: radial-gradient(circle at 20% 50%,rgba(251,191,36,0.05) 0%,transparent 50%),radial-gradient(circle at 80% 20%,rgba(251,191,36,0.03) 0%,transparent 50%);
}

[data-theme="dark"] {
  --bg: #1a1a1a;
  --bg-card: #242424;
  --bg-nav: rgba(26,26,26,0.82);
  --text: #e0e0e0;
  --text-secondary: #a0a0a0;
  --text-muted: #808080;
  --text-dim: #666;
  --border: #333;
  --accent: #fbbf24;
  --accent-hover: #f59e0b;
  --accent-light: #3d2e0a;
  --accent-border: #5c3d0a;
  --code-bg: #1e1e1e;
  --code-lang-bg: #2a2a2a;
  --layer-l1-bg: #0a2a1a;
  --layer-l2-bg: #0a1a2a;
  --layer-l3-bg: #2a1a0a;
  --layer-l4-bg: #1a0a2a;
  --layer-l5-bg: #2a0a0a;
  --hero-gradient: linear-gradient(180deg,#2a2a2a 0%,#1e1e1e 50%,#1a1a1a 100%);
  --table-hover: #2a2a15;
  --overlay-bg: rgba(0,0,0,0.7);
  --shadow: 0 1px 3px rgba(0,0,0,0.3);
  --shadow-hover: 0 8px 24px rgba(251,191,36,0.08);
  --math-bg: #1a1a2a;
  --math-border: #1e3a5f;
  --note-bg: #3d2e0a;
  --note-border: #5c3d0a;
  --note-color: #fbbf24;
  --progress-gradient: linear-gradient(90deg,#6366f1,#8b5cf6,#a78bfa,#c084fc);
  --hero-pattern: radial-gradient(circle at 20% 50%,rgba(251,191,36,0.04) 0%,transparent 50%),radial-gradient(circle at 80% 20%,rgba(139,92,246,0.02) 0%,transparent 50%);
}

body{
  font-family:-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,'Noto Sans SC','Microsoft YaHei',sans-serif;
  background:var(--bg);color:var(--text);line-height:1.75;overflow-x:hidden;
  transition:background 0.3s,color 0.3s;
  display:flex;flex-direction:column;min-height:100vh
}
#footer{margin-top:auto}

/* ─── Navbar ─────────── */
.navbar{
  position:fixed;top:0;left:0;right:0;z-index:100;
  background:var(--bg-nav);backdrop-filter:blur(20px) saturate(180%);
  -webkit-backdrop-filter:blur(20px) saturate(180%);
  border-bottom:1px solid var(--border);transition:background 0.3s
}
.nav-inner{
  max-width:1100px;margin:0 auto;
  display:flex;align-items:center;justify-content:space-between;
  padding:0.7rem 1.5rem
}
.nav-logo{
  font-size:1.1rem;font-weight:800;color:var(--accent);text-decoration:none;letter-spacing:0.03em
}
.nav-links{display:flex;gap:1.8rem;align-items:center}
.nav-links a{
  color:var(--text-secondary);text-decoration:none;font-size:0.85rem;transition:color 0.2s;position:relative
}
.nav-links a:hover{color:var(--accent)}
.nav-links a::after{
  content:'';position:absolute;bottom:-4px;left:0;right:0;
  height:2px;background:#eab308;transform:scaleX(0);transition:transform 0.25s
}
.nav-links a:hover::after{transform:scaleX(1)}
.nav-dropdown{position:relative;display:flex;align-items:center}
.nav-dropdown>a{cursor:pointer;position:static}
.nav-dropdown>a::after{display:none}
.nav-dropdown-menu{
  position:absolute;top:100%;left:-0.8rem;min-width:160px;
  background:var(--bg-card);border:1px solid var(--border);border-radius:10px;
  box-shadow:0 8px 24px rgba(0,0,0,0.1);opacity:0;visibility:hidden;
  transform:translateY(6px);transition:all 0.2s;z-index:50;padding:0.4rem 0
}
.nav-dropdown:hover .nav-dropdown-menu{opacity:1;visibility:visible;transform:translateY(0)}
.nav-dropdown-menu a{
  display:block;padding:0.45rem 1rem;font-size:0.8rem;color:var(--text-secondary);
  text-decoration:none;transition:background 0.15s;white-space:nowrap
}
.nav-dropdown-menu a:hover{background:var(--accent-light);color:var(--accent)}
.nav-dropdown-menu a::after{display:none}
.ndm-divider{height:1px;background:var(--border);margin:0.2rem 0.6rem}
.ndm-label{padding:0.35rem 1rem 0.15rem;font-size:0.68rem;font-weight:700;color:var(--text-dim);text-transform:uppercase;letter-spacing:0.03em}
.ndm-sub{padding-left:2rem!important;font-size:0.78rem!important}
.nav-actions{display:flex;align-items:center;gap:0.4rem}
.nav-toggle{display:none;background:none;border:none;color:var(--text-secondary);font-size:1.4rem;cursor:pointer}
.theme-toggle{
  background:none;border:none;color:var(--text-secondary);font-size:1.1rem;
  cursor:pointer;padding:0.2rem 0.4rem;border-radius:6px;transition:all 0.2s;line-height:1
}
.theme-toggle:hover{color:var(--accent);background:var(--accent-light)}

/* ─── Hero ───────────── */
.hero{
  min-height:50vh;display:flex;align-items:center;justify-content:center;
  position:relative;overflow:hidden;padding:5rem 1.5rem 2.5rem;
  background:var(--hero-gradient)
}
.hero::before{
  content:'';position:absolute;inset:0;background:var(--hero-pattern);pointer-events:none
}
.hero-content{position:relative;text-align:center;max-width:700px}
.hero-badge{
  display:inline-block;padding:0.3rem 1rem;border-radius:20px;
  background:var(--accent-light);border:1px solid var(--accent-border);
  font-size:0.78rem;font-weight:600;color:var(--accent-hover);margin-bottom:1.2rem;
  letter-spacing:0.02em
}
.hero-title{
  font-size:clamp(2.4rem,7vw,4.5rem);font-weight:900;letter-spacing:-0.01em;
  color:var(--text);margin-bottom:0.5rem;line-height:1.15
}
.hero-version{
  font-size:0.78rem;color:var(--text-dim);margin-top:-0.5rem;margin-bottom:0.8rem
}
.hero-sub{
  font-size:1.05rem;color:var(--text-muted);line-height:1.7;margin-bottom:1rem
}
.section-nav{display:flex;flex-wrap:wrap;gap:0.3rem;justify-content:center;margin-top:0.8rem}
.sn-btn{
  padding:0.35rem 0.8rem;border-radius:8px;border:1px solid var(--border);
  background:var(--bg-card);font-size:0.75rem;color:var(--text-secondary);
  cursor:pointer;transition:all 0.2s;white-space:nowrap
}
.sn-btn:hover{border-color:#fbbf24;color:var(--accent)}
.sn-btn.active{background:var(--accent);color:#fff;border-color:var(--accent)}
.hero-scroll{
  position:absolute;bottom:2rem;left:50%;transform:translateX(-50%);
  font-size:0.75rem;color:var(--text-dim);animation:bounce 2s infinite
}
@keyframes bounce{0%,100%{transform:translateX(-50%) translateY(0)}50%{transform:translateX(-50%) translateY(8px)}}

/* ─── Section ────────── */
.section{padding:3rem 1.5rem;max-width:1400px;margin:0 auto}
.section-header{text-align:center;margin-bottom:2rem}
.section-header h2{font-size:1.4rem;font-weight:700;margin-bottom:0.25rem;color:var(--text)}
.section-header p{color:var(--text-muted);font-size:0.82rem}

/* ─── Knowledge Cards ─── */
.knowledge-grid{
  display:grid;
  grid-template-columns:repeat(auto-fill,minmax(240px,360px));
  gap:0.5rem;
  max-width:1400px;margin:0 auto
}
.knowledge-card{
  padding:1.2rem 1.3rem;border-radius:12px;
  background:var(--bg-card);border:1px solid var(--border);
  transition:all 0.3s cubic-bezier(0.4,0,0.2,1);cursor:pointer;
  box-shadow:var(--shadow);animation:cardIn 0.4s ease both
}
.knowledge-card:nth-child(2){animation-delay:0.03s}
.knowledge-card:nth-child(3){animation-delay:0.06s}
.knowledge-card:nth-child(4){animation-delay:0.09s}
.knowledge-card:nth-child(5){animation-delay:0.12s}
.knowledge-card:nth-child(6){animation-delay:0.15s}
@keyframes cardIn{from{opacity:0;transform:translateY(12px)}to{opacity:1;transform:translateY(0)}}
.knowledge-card:hover{
  border-color:#fbbf24;transform:translateY(-3px);
  box-shadow:var(--shadow-hover)
}
.knowledge-card--soon{
  opacity:0.55;cursor:default;position:relative
}
.knowledge-card--soon::after{
  content:'即将上线';position:absolute;top:0.6rem;right:0.8rem;
  font-size:0.65rem;padding:0.15rem 0.5rem;border-radius:6px;
  background:var(--code-lang-bg);color:var(--text-dim)
}
.knowledge-card--soon:hover{transform:none;border-color:var(--border);box-shadow:none}
.kc-icon{font-size:1.8rem;margin-bottom:0.35rem}
.knowledge-card h3{font-size:0.88rem;font-weight:700;margin-bottom:0.2rem;color:var(--text)}
.knowledge-card p{font-size:0.75rem;color:var(--text-muted);line-height:1.45}
.kc-tags{display:flex;gap:0.25rem;flex-wrap:wrap;margin-top:0.45rem}
.kc-tags span{
  padding:0.1rem 0.45rem;border-radius:5px;
  background:var(--accent-light);font-size:0.65rem;color:var(--accent-hover)
}
.kc-group-header{
  grid-column:1/-1;font-size:0.72rem;font-weight:700;color:var(--accent);
  padding:0.8rem 0 0.4rem;margin-top:0.5rem;letter-spacing:0.06em;text-transform:uppercase;
  border-bottom:2px solid var(--accent-border);position:relative
}
.kc-group-header::after{
  content:'';position:absolute;bottom:-2px;left:0;width:60px;height:2px;background:var(--accent);border-radius:1px
}
.kc-group-header:first-child{padding-top:0;margin-top:0}

/* ─── Roadmap Cards ──── */
.roadmap-tree{max-width:900px;margin:0 auto;display:flex;flex-direction:column;gap:0.6rem}
.rp-card{
  background:var(--bg-card);border:1px solid var(--border);border-radius:14px;
  overflow:hidden;transition:all 0.3s;box-shadow:var(--shadow)
}
.rp-card:hover{border-color:#fbbf24}
.rp-header{
  display:flex;align-items:center;gap:0.6rem;padding:0.9rem 1.2rem;
  cursor:pointer;user-select:none;transition:background 0.2s
}
.rp-header:hover{background:var(--accent-light)}
.rp-icon{font-size:1.3rem}
.rp-title{font-size:0.95rem;font-weight:800;color:var(--text)}
.rp-desc{font-size:0.78rem;color:var(--text-dim);margin-left:auto}
.rp-count{font-size:0.68rem;color:var(--text-dim);white-space:nowrap}
.rp-toggle{font-size:0.7rem;color:var(--text-dim);transition:transform 0.3s}
.rp-card:not(.collapsed) .rp-toggle{transform:rotate(180deg)}
.rp-body{overflow:hidden;transition:all 0.3s}
.rp-card.collapsed .rp-body{max-height:0;opacity:0}
.rp-card:not(.collapsed) .rp-body{max-height:800px;opacity:1}
.rp-flow{display:flex;gap:0;padding:0.8rem 1.2rem 1rem;align-items:flex-start;overflow-x:auto}
.rp-stage{
  flex:1 1 0;min-width:150px;position:relative
}
.rp-stage+.rp-stage{margin-left:0.5rem;padding-left:1.8rem}
.rp-stage+.rp-stage::before{
  content:'→';position:absolute;left:0;top:50%;transform:translateY(-50%);
  font-size:1.2rem;color:var(--accent);font-weight:700
}
.rp-stage-label{
  font-size:0.62rem;font-weight:700;color:var(--accent);text-transform:uppercase;
  letter-spacing:0.06em;margin-bottom:0.5rem;display:flex;align-items:center;gap:0.2rem;
  border-bottom:2px solid var(--accent-border);padding-bottom:0.35rem
}
.rp-stage-icon{font-size:0.8rem}
.rp-items{display:flex;flex-direction:column;gap:0.3rem}
.rt-leaf{
  display:flex;align-items:center;gap:0.35rem;
  padding:0.35rem 0.55rem;border-radius:8px;font-size:0.72rem;
  border:1px solid var(--border);background:var(--bg);
  color:var(--text-secondary);cursor:pointer;transition:all 0.15s
}
.rt-leaf:hover{background:var(--accent-light);border-color:#fbbf24;color:var(--accent);transform:translateX(3px)}
.rt-leaf-dot{width:7px;height:7px;border-radius:50%;flex-shrink:0}
.rt-leaf-dot.l1{background:#059669}.rt-leaf-dot.l2{background:#2563eb}.rt-leaf-dot.l3{background:#ea580c}.rt-leaf-dot.l4{background:#7c3aed}.rt-leaf-dot.l5{background:#dc2626}
.rt-leaf-ext{border:1px dashed #14b8a6;background:#f0fdfa;color:#0f766e}
.rt-leaf-ext:hover{background:#ccfbf1;border-color:#0d9488;color:#115e59}
.rt-leaf-dot.ext{background:#14b8a6}

@media(max-width:768px){
  .rp-flow{flex-direction:column;gap:0.4rem}
  .rp-stage+.rp-stage{margin-left:0;padding-left:0}
  .rp-stage+.rp-stage::before{display:none}
}

/* ─── Guestbook ──────── */
.guestbook-list{max-width:700px;margin:0 auto;padding:0 1.5rem}
.gb-msg{
  background:var(--bg-card);border:1px solid var(--border);border-radius:10px;
  padding:1rem 1.2rem;margin-bottom:0.8rem;transition:border-color 0.2s
}
.gb-msg:hover{border-color:#fbbf24}
.gb-msg-header{display:flex;justify-content:space-between;align-items:baseline;margin-bottom:0.4rem}
.gb-msg-title{font-size:0.88rem;font-weight:700;color:var(--text)}
.gb-msg-time{font-size:0.68rem;color:var(--text-dim);white-space:nowrap}
.gb-msg-body{font-size:0.82rem;color:var(--text-secondary);line-height:1.75;white-space:pre-wrap}

/* ─── Footer ─────────── */
footer{
  background:var(--bg-card);border-top:1px solid var(--border);
  padding:2rem 1.5rem 1rem;width:100%
}
.footer-inner{
  max-width:1100px;margin:0 auto;
  display:grid;grid-template-columns:2fr 1fr 1fr;gap:2rem
}
.footer-brand h3{font-size:1rem;font-weight:800;color:var(--accent);margin-bottom:0.3rem}
.footer-brand p{font-size:0.82rem;color:var(--text-dim)}
.footer-subnote{font-size:0.75rem;color:var(--text-dim);margin-top:0.25rem}
.footer-links h4{font-size:0.82rem;color:var(--text-secondary);margin-bottom:0.6rem}
.footer-links a{
  display:block;color:var(--text-muted);text-decoration:none;font-size:0.82rem;
  margin-bottom:0.3rem;transition:color 0.2s
}
.footer-links a:hover{color:var(--accent)}
.footer-social{display:flex;gap:0.5rem;flex-wrap:wrap}
.social-link{
  padding:0.3rem 0.8rem;border-radius:8px;
  background:var(--accent-light);border:1px solid var(--accent-border);
  font-size:0.78rem;color:var(--accent-hover);text-decoration:none;transition:all 0.2s
}
.social-link:hover{background:var(--accent-border);color:#92400e}
.footer-bottom{
  text-align:center;padding-top:1.5rem;margin-top:1.5rem;
  border-top:1px solid var(--border)
}
.footer-bottom p{font-size:0.75rem;color:var(--text-dim)}

/* ═══ ARTICLE READER ═══════════════════════════════════════ */
.reader-overlay{
  position:fixed;inset:0;z-index:200;background:var(--overlay-bg);
  display:none;align-items:center;justify-content:center;
  backdrop-filter:blur(4px)
}
.reader-overlay.open{display:flex}
.reader-container{
  width:96vw;max-width:1400px;height:94vh;
  background:var(--bg);border-radius:16px;overflow:hidden;
  display:flex;flex-direction:column;
  box-shadow:0 20px 60px rgba(0,0,0,0.15);
  animation:readerIn 0.25s ease;
  transition:background 0.3s
}
@keyframes readerIn{from{opacity:0;transform:scale(0.97)}to{opacity:1;transform:scale(1)}}

/* ── topbar ── */
.reader-topbar{
  display:flex;align-items:center;justify-content:space-between;
  padding:0.6rem 1.2rem;border-bottom:1px solid var(--border);background:var(--bg-card);
  gap:1rem;flex-shrink:0;transition:background 0.3s
}
.reader-search-wrap{flex:1;max-width:400px}
.reader-search{
  width:100%;padding:0.45rem 0.8rem;border-radius:8px;
  border:1px solid var(--border);font-size:0.82rem;outline:none;
  background:var(--bg);color:var(--text);transition:border-color 0.2s
}
.reader-search:focus{border-color:#fbbf24}
.reader-search::placeholder{color:var(--text-dim)}
.reader-actions{display:flex;align-items:center;gap:0.8rem}
.layer-filters{display:flex;gap:0.25rem}
.lf-btn{padding:0.2rem 0.55rem;border-radius:6px;border:2px solid transparent;font-size:0.7rem;font-weight:700;cursor:pointer;transition:all 0.2s;opacity:0.35}
.lf-btn.active{opacity:1;border-color:currentColor}
.lf-l1{background:#d1fae5;color:#059669}
.lf-l2{background:#dbeafe;color:#2563eb}
.lf-l3{background:#ffedd5;color:#ea580c}
.lf-l4{background:#ede9fe;color:#7c3aed}
.lf-l5{background:#fee2e2;color:#dc2626}
.reader-close{
  width:32px;height:32px;border-radius:8px;border:none;
  background:var(--code-lang-bg);color:var(--text-secondary);font-size:1.2rem;
  cursor:pointer;transition:all 0.2s;display:flex;align-items:center;justify-content:center
}
.reader-close:hover{background:var(--border);color:var(--text)}

/* ── toc toggle ── */
.reader-toc-toggle{
  width:32px;height:32px;border-radius:8px;border:none;
  background:var(--code-lang-bg);color:var(--text-secondary);font-size:0.9rem;
  cursor:pointer;transition:all 0.2s;display:flex;align-items:center;justify-content:center
}
.reader-toc-toggle:hover{background:var(--border);color:var(--text)}
.reader-toc-toggle.toc-hidden{background:var(--accent);color:#fff}

/* ── font controls ── */
.font-ctrls{display:flex;gap:0.2rem}
.font-btn{
  width:28px;height:28px;border-radius:6px;border:none;
  background:var(--code-lang-bg);color:var(--text-secondary);font-size:0.7rem;font-weight:700;
  cursor:pointer;transition:all 0.2s;display:flex;align-items:center;justify-content:center
}
.font-btn:hover{background:var(--border);color:var(--text)}

/* ── body (toc + content) ── */
.reader-body{
  display:flex;flex:1;overflow:hidden
}
.reader-toc{
  width:250px;flex-shrink:0;overflow-y:auto;padding:1.2rem;
  background:var(--bg-card);border-right:1px solid var(--border);transition:width 0.3s
}
.reader-toc.collapsed{width:0;padding:0;border-right:none;overflow:hidden}
.toc-title{
  font-size:0.75rem;font-weight:700;color:var(--text-dim);text-transform:uppercase;
  letter-spacing:0.05em;margin-bottom:0.8rem
}
.toc-nav{display:flex;flex-direction:column;gap:0.15rem}
.toc-layer{margin-bottom:0.5rem}
.toc-layer-title{
  font-size:0.78rem;font-weight:600;color:var(--text);
  padding:0.35rem 0.5rem;border-radius:6px;cursor:pointer;
  transition:all 0.15s;display:flex;align-items:center;gap:0.4rem
}
.toc-layer-title:hover{background:var(--accent-light)}
.toc-layer-title.active{background:var(--accent-light);color:var(--accent);font-weight:700}
.toc-layer-title .toc-dot{
  width:8px;height:8px;border-radius:50%;flex-shrink:0
}
.toc-dot.l1{background:#059669}
.toc-dot.l2{background:#2563eb}
.toc-dot.l3{background:#ea580c}
.toc-dot.l4{background:#7c3aed}
.toc-dot.l5{background:#dc2626}

/* ─── Reader Cards Sidebar ─── */
.reader-cards-sidebar{width:280px;flex-shrink:0;overflow-y:auto;padding:1.2rem;background:var(--bg-card);border-left:1px solid var(--border);transition:width .3s;display:none}
.reader-cards-sidebar.open{display:block}
.reader-cards-sidebar.collapsed{width:0;padding:0;border-left:none;overflow:hidden}
.cards-nav{display:flex;flex-direction:column;gap:.3rem}
.cards-nav .rc-group{font-size:.68rem;font-weight:700;color:var(--accent);padding:.6rem 0 .2rem;border-bottom:1px solid var(--accent-border);margin-bottom:.2rem}
.cards-nav .rc-card{font-size:.75rem;color:var(--text-secondary);padding:.25rem .4rem;border-radius:6px;cursor:pointer;transition:all .15s;display:flex;align-items:center;gap:.4rem}
.cards-nav .rc-card:hover{background:var(--accent-light);color:var(--accent)}
.cards-nav .rc-card.current{background:var(--accent-light);color:var(--accent);font-weight:600}
.cards-nav .rc-card .rc-icon{width:18px;text-align:center}
.reader-cards-toggle{background:none;border:1px solid var(--border);color:var(--text-secondary);cursor:pointer;padding:.25rem .4rem;border-radius:6px;font-size:.85rem;transition:all .15s}
.reader-cards-toggle:hover{background:var(--border);color:var(--text)}
.reader-cards-toggle.active{background:var(--accent);color:#fff;border-color:var(--accent)}

/* ── font scaling ── */
html.fs-0{font-size:14px}
html.fs-1{font-size:16px}
html.fs-2{font-size:18px}
html.fs-3{font-size:20px}
html.fs-4{font-size:22px}
html.fs-5{font-size:24px}
.reader-content{
  flex:1;overflow-y:auto;padding:2rem 2.5rem;min-height:300px
}
.render-ok{background:#d1fae5;color:#065f46;padding:0.5rem 0.8rem;border-radius:8px;margin-bottom:1rem;font-size:0.8rem;font-weight:600}
.reader-content h1{
  font-size:1.8rem;font-weight:900;margin-bottom:0.3rem;color:var(--text)
}
.reader-content h2{
  font-size:1.3rem;font-weight:700;margin:2rem 0 0.8rem;color:var(--text);
  padding-bottom:0.4rem;border-bottom:2px solid var(--accent-border)
}
.reader-content h3{
  font-size:1.05rem;font-weight:700;margin:1.5rem 0 0.5rem;color:var(--text)
}
.reader-content p{
  font-size:0.88rem;color:var(--text-secondary);line-height:1.85;margin-bottom:0.8rem
}
.reader-content a{color:var(--accent);text-decoration:underline;text-underline-offset:2px}
.reader-content a:hover{color:var(--accent-hover)}

/* layer block */
.layer-block{
  margin:1.5rem 0;padding:0.8rem 1rem 0.6rem;
  border-radius:10px;border-left:3px solid;position:relative
}
.layer-block.l1{border-color:#059669;background:var(--layer-l1-bg)}
.layer-block.l2{border-color:#2563eb;background:var(--layer-l2-bg)}
.layer-block.l3{border-color:#ea580c;background:var(--layer-l3-bg)}
.layer-block.l4{border-color:#7c3aed;background:var(--layer-l4-bg)}
.layer-block.l5{border-color:#dc2626;background:var(--layer-l5-bg)}

.layer-label{
  display:inline-block;font-size:0.65rem;font-weight:800;padding:0.1rem 0.45rem;border-radius:4px;
  letter-spacing:0.03em;margin-bottom:0.5rem
}
.l1 .layer-label{background:#059669;color:#fff}
.l2 .layer-label{background:#2563eb;color:#fff}
.l3 .layer-label{background:#ea580c;color:#fff}
.l4 .layer-label{background:#7c3aed;color:#fff}
.l5 .layer-label{background:#dc2626;color:#fff}

.layer-block h2{margin-top:0;border-bottom:1px solid var(--border);font-size:1.2rem}
.layer-block h3{font-size:0.95rem;margin-top:1.2rem}

/* code block */
.code-block{
  margin:0.8rem 0;border-radius:8px;overflow:hidden;border:1px solid var(--border)
}
.code-block .cb-lang{
  display:block;padding:0.25rem 0.8rem;background:var(--code-lang-bg);font-size:0.68rem;color:var(--text-dim);
  text-transform:uppercase;letter-spacing:0.04em
}
.code-block pre{
  padding:0.8rem 1rem;overflow-x:auto;
  font-family:'SF Mono','Fira Code','Cascadia Code','Consolas',monospace;
  font-size:0.78rem;line-height:1.6;background:var(--code-bg);color:var(--text-secondary);
  white-space:pre;tab-size:2
}

/* note block */
.note-block{
  margin:0.8rem 0;padding:0.7rem 1rem;border-radius:8px;
  background:var(--note-bg);border:1px solid var(--note-border);font-size:0.82rem;color:var(--note-color);line-height:1.7
}
.note-block strong{color:var(--accent)}

/* math block */
.math-block{
  margin:0.8rem 0;padding:0.7rem 1rem;border-radius:8px;
  background:var(--math-bg);border:1px solid var(--math-border);
  font-size:0.95rem;line-height:1.8;text-align:center;overflow-x:auto
}
.math-block .katex{font-size:1em!important}
.math-inline{display:inline;background:transparent;border:none;padding:0;margin:0;text-align:left}
.math-inline .katex{font-size:1em!important}

/* list */
.reader-content ul,.reader-content ol{
  margin:0.5rem 0 0.8rem 1.2rem;font-size:0.85rem;color:var(--text-secondary);line-height:1.8
}
.reader-content li{margin-bottom:0.2rem}

/* table */
.rb-table-wrap{margin:0.8rem 0;overflow-x:auto;border-radius:8px;border:1px solid var(--border)}
.rb-table{border-collapse:collapse;width:100%;font-size:0.78rem}
.rb-table th,.rb-table td{padding:0.45rem 0.7rem;text-align:left;border:1px solid var(--border)}
.rb-table th{background:var(--bg);font-weight:700;color:var(--text);position:sticky;top:0}
.rb-table td{color:var(--text-secondary);background:var(--bg-card)}
.rb-table tr:hover td{background:var(--table-hover)}

/* visual bars & charts */
.viz-bar-wrap{margin:0.6rem 0;display:flex;flex-direction:column;gap:0.3rem}
.viz-bar-row{display:flex;align-items:center;gap:0.6rem;font-size:0.75rem}
.viz-bar-label{min-width:180px;text-align:left;color:var(--text-secondary);font-weight:600;white-space:nowrap}
.viz-bar-fill{height:18px;border-radius:4px;min-width:2px;transition:width 0.3s}
.viz-bar-val{color:var(--text-dim);font-size:0.7rem;min-width:50px}
.viz-bar-fill.l1{background:linear-gradient(90deg,#059669,#34d399)}
.viz-bar-fill.l2{background:linear-gradient(90deg,#2563eb,#60a5fa)}
.viz-bar-fill.l3{background:linear-gradient(90deg,#ea580c,#fb923c)}
.viz-bar-fill.l4{background:linear-gradient(90deg,#7c3aed,#a78bfa)}
.viz-bar-fill.l5{background:linear-gradient(90deg,#dc2626,#f87171)}

/* mermaid diagrams */
.mermaid-block{margin:0.8rem 0;padding:0.5rem;border-radius:8px;background:var(--bg-card);border:1px solid var(--border);overflow-x:auto;text-align:center}
.mermaid-block svg{max-width:100%}

/* citation sup */
.reader-content sup a{
  font-size:0.68rem;color:var(--accent);text-decoration:none;font-weight:600;
  padding:0 0.15rem
}
.reader-content sup a:hover{color:var(--accent-hover);text-decoration:underline}

/* ── references ── */
.reader-ref-header{
  display:flex;align-items:center;justify-content:space-between;
  padding:0.6rem 2.5rem;border-top:2px solid var(--border);background:var(--bg-card);
  font-size:0.88rem;font-weight:700;color:var(--text);transition:background 0.3s
}
.reader-ref-toggle{
  background:none;border:none;color:var(--text-muted);font-size:0.7rem;cursor:pointer;font-weight:600
}
.reader-ref-toggle:hover{color:var(--accent)}
.reader-references{
  padding:1.2rem 2.5rem 2rem;background:var(--bg-card);transition:all 0.3s
}
.reader-references.collapsed{padding:0;max-height:0;overflow:hidden}
.ref-item{margin-bottom:0.45rem;font-size:0.78rem;color:var(--text-secondary);line-height:1.6}
.ref-item .ref-num{color:var(--accent);font-weight:700;margin-right:0.3rem}
.ref-item a{color:var(--accent);text-decoration:none;font-size:0.72rem}
.ref-item a:hover{text-decoration:underline;color:var(--accent-hover)}
.ref-item a:visited{color:var(--text-dim)}

/* search highlight */
mark.search-hl{background:var(--accent-border);color:var(--text);border-radius:2px;padding:0 0.1rem}

/* hidden by search */
.layer-block.hidden-by-search,.content-block.hidden-by-search{display:none}

/* ─── Responsive ─────── */
@media(max-width:768px){
  .nav-links{display:none}
  .nav-links.open{
    display:flex;flex-direction:column;position:absolute;top:100%;left:0;right:0;
    background:var(--bg-card);padding:1rem 1.5rem;gap:1rem;
    border-bottom:1px solid var(--border)
  }
  .nav-toggle{display:block}
  .footer-inner{grid-template-columns:1fr;gap:1.5rem}
  .knowledge-grid{grid-template-columns:1fr}
  .reader-container{width:100vw;height:100vh;border-radius:0}
  .reader-toc{display:none}
  .reader-toc.open{
    display:block;position:absolute;top:0;left:0;bottom:0;z-index:10;
    width:260px;box-shadow:4px 0 20px rgba(0,0,0,0.1)
  }
  .reader-content{padding:1rem}
  .reader-topbar{flex-wrap:wrap;padding:0.5rem 0.8rem}
  .reader-search-wrap{max-width:100%}
  .reader-references{padding:1rem}
  .hero-title{font-size:2rem}
  .hero-search-wrap{max-width:90vw}
  .knowledge-card{padding:0.9rem 1rem}
  .kc-tags span{font-size:0.6rem}
  .gb-msg{padding:0.8rem 1rem}
}

@media(max-width:480px){
  .hero{padding:3rem 1rem 1.5rem;min-height:40vh}
  .hero-title{font-size:1.6rem}
  .hero-sub{font-size:0.85rem}
  .section{padding:2rem 0.8rem}
  .reader-topbar{gap:0.4rem}
  .layer-filters{gap:0.1rem}
  .lf-btn{padding:0.15rem 0.4rem;font-size:0.65rem}
  .reader-content h1{font-size:1.3rem}
  .reader-content h2{font-size:1rem}
  .reader-content h3{font-size:0.9rem}
  .reader-content p{font-size:0.82rem}
  .rb-table{font-size:0.7rem}
  .rb-table th,.rb-table td{padding:0.3rem 0.45rem}
}

/* ─── Hero Search ────── */
.hero-search-wrap{max-width:500px;margin:0.8rem auto 0;display:flex;gap:0.4rem}
.hero-search{
  flex:1;padding:0.55rem 1rem;border-radius:10px;border:1px solid var(--border);
  background:var(--bg-card);color:var(--text);font-size:0.85rem;outline:none;transition:all 0.2s
}
.hero-search:focus{border-color:#fbbf24;box-shadow:0 0 0 3px rgba(251,191,36,0.15)}
.hero-search::placeholder{color:var(--text-dim)}

/* ─── Print (PDF Export) ── */
.print-btn{
  width:32px;height:32px;border-radius:8px;border:none;
  background:var(--code-lang-bg);color:var(--text-secondary);font-size:0.9rem;
  cursor:pointer;transition:all 0.2s;display:flex;align-items:center;justify-content:center
}
.print-btn:hover{background:var(--border);color:var(--text)}

@media print{
  .navbar,.hero,#footer,.reader-overlay,.print-btn,.reader-toc-toggle,.font-ctrls,.reader-close,.reader-topbar,.reader-toc,.reader-footer,.reader-references{display:none!important}
  .reader-overlay.open{position:static;background:none;display:block}
  .reader-container{width:100%;height:auto;box-shadow:none;border-radius:0}
  .reader-body{overflow:visible}
  .reader-content{overflow:visible;padding:0}
  .layer-block{break-inside:avoid;border:1px solid #ccc;margin:0.8rem 0}
  .code-block,.rb-table-wrap,.note-block,.math-block{break-inside:avoid}
  body{font-size:11pt;line-height:1.5;color:#000;background:#fff}
  .reader-content h1{font-size:18pt}
  .reader-content h2{font-size:14pt}
  .reader-content h3{font-size:12pt}
  a{color:#000;text-decoration:underline}
}

/* ─── Reading Progress ── */
.progress-bar{
  position:fixed;top:0;left:0;height:3px;background:var(--progress-gradient);
  z-index:999;transition:width 0.3s
}
.kc-progress{
  font-size:0.6rem;color:var(--text-dim);margin-top:0.3rem;display:flex;align-items:center;gap:0.3rem
}
.kc-progress-fill{height:4px;border-radius:2px;background:var(--accent-light);flex:1;overflow:hidden}
.kc-progress-fill div{height:100%;border-radius:2px;background:var(--accent);transition:width 0.3s}

/* ─── Language Badge ──── */
.lang-badge{
  display:inline-block;font-size:0.6rem;padding:0.1rem 0.35rem;border-radius:4px;
  margin-left:0.3rem;vertical-align:middle
}
.lang-badge.original{background:#d1fae5;color:#065f46}
.lang-badge.translated{background:#dbeafe;color:#1e40af}
.kc-lang{position:absolute;top:0.6rem;right:0.8rem;font-size:0.6rem}
.knowledge-card{position:relative}

/* ─── Cross-link popup ─── */
.xref-link{color:var(--accent);cursor:pointer;text-decoration:underline dotted;text-underline-offset:3px}
.xref-link:hover{color:var(--accent-hover)}

/* ─── Back to Top ─────── */
.back-to-top{
  position:fixed;bottom:2rem;right:2rem;z-index:90;
  width:40px;height:40px;border-radius:12px;border:1px solid var(--border);
  background:var(--bg-card);color:var(--text-secondary);font-size:1.1rem;
  cursor:pointer;opacity:0;visibility:hidden;transform:translateY(10px);
  transition:all 0.3s;box-shadow:var(--shadow);display:flex;align-items:center;justify-content:center
}
.back-to-top.visible{opacity:1;visibility:visible;transform:translateY(0)}
.back-to-top:hover{background:var(--accent);color:#fff;border-color:var(--accent)}

/* ─── Knowledge Page TOC ── */
.kg-toc{
  position:fixed;left:2rem;top:5rem;z-index:70;
  width:170px;max-height:calc(100vh - 8rem);overflow-y:auto
}
.kg-toc::-webkit-scrollbar{width:3px}
.kg-toc::-webkit-scrollbar-thumb{background:var(--border);border-radius:2px}
.kg-toc-title{
  font-size:0.62rem;font-weight:700;color:var(--text-dim);text-transform:uppercase;
  letter-spacing:0.08em;margin-bottom:0.6rem
}
.kg-toc-list{display:flex;flex-direction:column;gap:0.1rem}
.kg-toc-item{
  display:block;padding:0.25rem 0.5rem;font-size:0.73rem;color:var(--text-secondary);
  text-decoration:none;transition:all 0.15s;border-left:2px solid transparent;
  border-radius:0 4px 4px 0
}
.kg-toc-item:hover{color:var(--accent);background:var(--accent-light)}
.kg-toc-item.active{color:var(--accent);font-weight:700;border-left-color:var(--accent);background:var(--accent-light)}
.kg-toc-item .kg-toc-emoji{font-size:0.8rem;margin-right:0.25rem;display:inline-block;width:1.1rem;text-align:center}
.kg-page .section{margin-left:14rem;max-width:calc(100% - 16rem)}

@media(max-width:900px){
  .kg-toc{display:none}
  .kg-page .section{margin-left:auto;max-width:1400px}
}