/* ============================================
   Design Token System
   Health Knowledge Base - v2.0
   ============================================ */
:root {
  --color-bg: #f0fdf4;
  --color-surface: #ffffff;
  --color-border: #dcfce7;
  --color-border-strong: #bbf7d0;
  --color-text: #052e16;
  --color-text-secondary: #166534;
  --color-text-muted: #94a3b8;
  --color-primary: #16a34a;
  --color-primary-light: #f0fdf4;
  --color-primary-dark: #15803d;
  --color-primary-ring: rgba(22,163,74,0.2);
  --color-accent: #22c55e;
  --color-gold: #f59e0b;
  --color-gold-light: #fef3c7;
  --color-gold-dark: #d97706;
  --color-danger: #ef4444;
  --color-success: #22c55e;
  --color-header-bg: #052e16;
  --color-header-text: #ffffff;
  --color-header-muted: #86efac;
  --color-hero-bg: #0f172a;
  --color-hero-text: #ffffff;
  --color-hero-muted: #94a3b8;
  --color-hero-accent: #4ade80;
  --font-sans: -apple-system, PingFang SC, Microsoft YaHei, Noto Sans SC, system-ui, sans-serif;
  --font-mono: SF Mono, Fira Code, Consolas, monospace;
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.8125rem;
  --font-size-base: 0.9375rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.5rem;
  --font-size-2xl: 2rem;
  --font-size-3xl: 2.5rem;
  --font-size-hero: clamp(2rem, 5vw, 3.25rem);
  --line-height-tight: 1.25;
  --line-height-base: 1.6;
  --line-height-relaxed: 1.75;
  --space-1: 0.25rem;
  --space-2: 0.5rem;
  --space-3: 0.75rem;
  --space-4: 1rem;
  --space-5: 1.25rem;
  --space-6: 1.5rem;
  --space-8: 2rem;
  --space-10: 2.5rem;
  --space-12: 3rem;
  --space-16: 4rem;
  --space-20: 5rem;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;
  --shadow-sm: 0 1px 3px rgba(15,23,42,0.06);
  --shadow-md: 0 4px 12px rgba(15,23,42,0.08);
  --shadow-lg: 0 8px 30px rgba(15,23,42,0.1);
  --shadow-xl: 0 12px 40px rgba(15,23,42,0.12);
  --shadow-header: 0 1px 3px rgba(15,23,42,0.15);
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
  --transition-slow: 350ms ease;
  --container-max: 1200px;
  --container-narrow: 800px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-bg: #0f172a;
    --color-surface: #1e293b;
    --color-border: #1e293b;
    --color-border-strong: #334155;
    --color-text: #f1f5f9;
    --color-text-secondary: #cbd5e1;
    --color-text-muted: #64748b;
    --color-primary: #22c55e;
    --color-primary-light: rgba(34,197,94,0.1);
    --color-primary-dark: #16a34a;
    --color-primary-ring: rgba(34,197,94,0.25);
    --color-gold-light: rgba(245,158,11,0.15);
    --color-header-bg: #020617;
    --color-header-text: #f1f5f9;
    --color-header-muted: #4ade80;
    --color-hero-bg: #020617;
    --color-hero-text: #f1f5f9;
    --color-hero-muted: #64748b;
    --color-hero-accent: #4ade80;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.3);
    --shadow-md: 0 4px 12px rgba(0,0,0,0.35);
    --shadow-lg: 0 8px 30px rgba(0,0,0,0.4);
    --shadow-xl: 0 12px 40px rgba(0,0,0,0.45);
    --shadow-header: 0 1px 3px rgba(0,0,0,0.4);
  }
}

*,*::before,*::after{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth;-webkit-font-smoothing:antialiased}
body{font-family:var(--font-sans);font-size:var(--font-size-base);line-height:var(--line-height-base);color:var(--color-text);background:var(--color-bg);transition:background var(--transition-base),color var(--transition-base)}
::selection{background:var(--color-primary);color:#fff}
:focus-visible{outline:2px solid var(--color-primary);outline-offset:2px}
.container{max-width:var(--container-max);margin:0 auto;padding:0 var(--space-6)}
::-webkit-scrollbar{width:6px;height:6px}
::-webkit-scrollbar-track{background:transparent}
::-webkit-scrollbar-thumb{background:var(--color-border-strong);border-radius:3px}
::-webkit-scrollbar-thumb:hover{background:var(--color-text-muted)}

header{background:var(--color-header-bg);color:var(--color-header-text);padding:var(--space-4) 0;position:sticky;top:0;z-index:100;box-shadow:var(--shadow-header)}
header .container{display:flex;justify-content:space-between;align-items:center}
.logo{font-size:var(--font-size-xl);font-weight:700;letter-spacing:-0.3px;display:flex;align-items:center;gap:var(--space-1)}
.logo span{color:var(--color-accent)}
nav{display:flex;align-items:center;gap:var(--space-6)}
nav a{color:var(--color-header-muted);text-decoration:none;font-size:var(--font-size-sm);font-weight:500;transition:color var(--transition-fast);position:relative}
nav a::after{content:'';position:absolute;bottom:-2px;left:0;width:0;height:2px;background:var(--color-accent);transition:width var(--transition-base);border-radius:1px}
nav a:hover{color:var(--color-accent)}
nav a:hover::after{width:100%}
nav a.cta{background:var(--color-gold);color:#052e16;padding:var(--space-2) var(--space-5);border-radius:var(--radius-full);font-weight:600;font-size:var(--font-size-sm);transition:background var(--transition-fast),transform var(--transition-fast),box-shadow var(--transition-fast)}
nav a.cta:hover{background:var(--color-gold-dark);color:#fff;transform:translateY(-1px);box-shadow:0 4px 12px rgba(245,158,11,0.3)}
nav a.cta:hover::after{width:0}

.hero{text-align:center;padding:var(--space-16) 0 var(--space-12);background:var(--color-hero-bg);color:var(--color-hero-text);position:relative;overflow:hidden}
.hero::before{content:'';position:absolute;top:-50%;left:-50%;width:200%;height:200%;background:radial-gradient(circle at 25% 40%,rgba(34,197,94,0.06) 0%,transparent 50%),radial-gradient(circle at 75% 60%,rgba(34,197,94,0.04) 0%,transparent 50%);pointer-events:none}
.hero .container{position:relative;z-index:1}
.hero h1{font-size:var(--font-size-hero);font-weight:800;line-height:var(--line-height-tight);margin-bottom:var(--space-5);letter-spacing:-1px}
.hero h1 span{background:linear-gradient(135deg,var(--color-accent),var(--color-primary));-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}
.hero p{font-size:var(--font-size-lg);color:var(--color-hero-muted);max-width:600px;margin:0 auto var(--space-8);line-height:var(--line-height-relaxed)}
.hero-stats{display:flex;justify-content:center;gap:48px;padding-top:var(--space-8);border-top:1px solid rgba(255,255,255,0.08)}
.hero-stat{text-align:center}
.hero-stat-num{display:block;font-size:var(--font-size-2xl);font-weight:800;background:linear-gradient(135deg,var(--color-accent),var(--color-primary));-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text;line-height:1.2}
.hero-stat-label{display:block;font-size:var(--font-size-xs);color:rgba(255,255,255,0.5);margin-top:var(--space-1)}

.btn{display:inline-flex;align-items:center;justify-content:center;gap:var(--space-2);padding:var(--space-3) var(--space-8);border-radius:var(--radius-full);font-size:var(--font-size-sm);font-weight:600;text-decoration:none;cursor:pointer;border:none;transition:all var(--transition-fast);line-height:1;white-space:nowrap}
.btn:active{transform:scale(0.97)}
.btn-primary{background:var(--color-primary);color:#fff}
.btn-primary:hover{background:var(--color-primary-dark);box-shadow:0 4px 14px rgba(22,163,74,0.35)}
.btn-gold{background:var(--color-gold);color:#052e16}
.btn-gold:hover{background:var(--color-gold-dark);color:#fff;box-shadow:0 4px 14px rgba(245,158,11,0.35)}
.btn-outline{background:transparent;border:2px solid var(--color-primary);color:var(--color-primary)}
.btn-outline:hover{background:var(--color-primary);color:#fff;box-shadow:0 4px 14px rgba(22,163,74,0.25)}

.pricing-section{padding:var(--space-16) 0;background:var(--color-surface)}
.section-title{font-size:var(--font-size-2xl);font-weight:700;text-align:center;margin-bottom:var(--space-10);color:var(--color-text);letter-spacing:-0.3px}
.pricing{display:flex;justify-content:center;gap:var(--space-6);padding:var(--space-4) 0}
.card{background:var(--color-surface);border-radius:var(--radius-lg);padding:var(--space-8);width:340px;text-align:center;box-shadow:var(--shadow-lg);transition:transform var(--transition-base),box-shadow var(--transition-base),border-color var(--transition-base);position:relative;border:1px solid var(--color-border)}
.card:hover{transform:translateY(-4px);box-shadow:var(--shadow-xl);border-color:var(--color-primary)}
.card.popular{border:2px solid var(--color-gold)}
.card.popular:hover{border-color:var(--color-gold-dark)}
.card .badge{position:absolute;top:-12px;left:50%;transform:translateX(-50%);background:var(--color-gold);color:#052e16;padding:3px var(--space-4);border-radius:var(--radius-full);font-size:var(--font-size-xs);font-weight:600;letter-spacing:0.3px}
.card h3{font-size:var(--font-size-lg);font-weight:600;color:var(--color-text);margin-bottom:var(--space-2)}
.card .price{font-size:var(--font-size-3xl);font-weight:800;color:var(--color-text);margin:var(--space-4) 0}
.card .price sub{font-size:var(--font-size-base);font-weight:400;color:var(--color-text-secondary)}
.card .desc{color:var(--color-text-secondary);font-size:var(--font-size-sm);margin-bottom:var(--space-6)}
.card ul{list-style:none;text-align:left;margin-bottom:var(--space-6)}
.card ul li{padding:var(--space-2) 0;color:var(--color-text-secondary);font-size:var(--font-size-sm);display:flex;align-items:center;gap:var(--space-2)}
.card ul li::before{content:'';display:inline-block;width:18px;height:18px;flex-shrink:0;background:var(--color-accent);mask:url('data:image/svg+xml,%3Csvg xmlns=%22http://www.w3.org/2000/svg%22 viewBox=%220 0 24 24%22 fill=%22none%22 stroke=%22currentColor%22 stroke-width=%223%22%3E%3Cpolyline points=%2220 6 9 17 4 12%22%3E%3C/polyline%3E%3C/svg%3E') center/contain no-repeat;-webkit-mask:url('data:image/svg+xml,%3Csvg xmlns=%22http://www.w3.org/2000/svg%22 viewBox=%220 0 24 24%22 fill=%22none%22 stroke=%22currentColor%22 stroke-width=%223%22%3E%3Cpolyline points=%2220 6 9 17 4 12%22%3E%3C/polyline%3E%3C/svg%3E') center/contain no-repeat}

.categories{padding:var(--space-16) 0}
.grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:var(--space-5)}
.cat-card{background:var(--color-surface);border-radius:var(--radius-md);padding:var(--space-6);box-shadow:var(--shadow-sm);cursor:pointer;transition:all var(--transition-base);border:1px solid var(--color-border)}
.cat-card:hover{box-shadow:var(--shadow-md);transform:translateY(-2px);border-color:var(--color-primary)}
.cat-card h3{font-size:var(--font-size-lg);font-weight:600;margin-bottom:var(--space-2);color:var(--color-text)}
.cat-card p{color:var(--color-text-secondary);font-size:var(--font-size-sm);margin-bottom:var(--space-3)}
.cat-card .count{color:var(--color-primary);font-size:var(--font-size-xs);font-weight:600}
.cat-card.loading{cursor:default;animation:pulse 1.5s ease-in-out infinite}
@keyframes pulse{0%,100%{opacity:1}50%{opacity:0.5}}

.form-container{max-width:420px;margin:var(--space-16) auto;background:var(--color-surface);padding:var(--space-8);border-radius:var(--radius-lg);box-shadow:var(--shadow-md);border:1px solid var(--color-border)}
.form-container h2{text-align:center;margin-bottom:var(--space-6);font-size:var(--font-size-xl);font-weight:700}
.form-group{margin-bottom:var(--space-5)}
.form-group label{display:block;font-size:var(--font-size-sm);font-weight:600;margin-bottom:var(--space-2);color:var(--color-text-secondary)}
.form-group input,.form-group select{width:100%;padding:var(--space-3) var(--space-4);border:1px solid var(--color-border-strong);border-radius:var(--radius-md);font-size:var(--font-size-base);font-family:var(--font-sans);background:var(--color-surface);color:var(--color-text);transition:border-color var(--transition-fast),box-shadow var(--transition-fast)}
.form-group input:focus,.form-group select:focus{outline:none;border-color:var(--color-primary);box-shadow:0 0 0 3px var(--color-primary-ring)}
.form-group input::placeholder{color:var(--color-text-muted)}
.form-error{color:var(--color-danger);font-size:var(--font-size-sm);text-align:center;margin-top:var(--space-3)}

.level-beginner,.level-badge.beginner{background:var(--color-primary-light);color:var(--color-primary-dark);font-size:var(--font-size-xs);padding:2px 8px;border-radius:var(--radius-full);font-weight:600}
.level-intermediate,.level-badge.intermediate{background:var(--color-gold-light);color:#92400e;font-size:var(--font-size-xs);padding:2px 8px;border-radius:var(--radius-full);font-weight:600}
.level-badge.advanced{background:#fef2f2;color:#dc2626;font-size:var(--font-size-xs);padding:2px 8px;border-radius:var(--radius-full);font-weight:600}

.toast{position:fixed;top:var(--space-5);right:var(--space-5);background:var(--color-text);color:#fff;padding:var(--space-3) var(--space-6);border-radius:var(--radius-md);font-size:var(--font-size-sm);z-index:1000;opacity:0;transform:translateX(100px);transition:all 0.3s ease;box-shadow:var(--shadow-lg);pointer-events:none}
.toast.show{opacity:1;transform:translateX(0);pointer-events:auto}
.toast.success{background:var(--color-success)}
.toast.error{background:var(--color-danger)}

.vip-guard{text-align:center;padding:var(--space-16) var(--space-6);background:var(--color-surface);border-radius:var(--radius-lg);margin:var(--space-10) 0;border:1px solid var(--color-border)}
.vip-guard h2{margin-bottom:var(--space-4);font-size:var(--font-size-xl)}
.vip-guard p{color:var(--color-text-secondary);margin-bottom:var(--space-6)}

footer{background:var(--color-header-bg);color:var(--color-header-muted);text-align:center;padding:var(--space-6) 0;font-size:var(--font-size-sm)}

.kb-layout{display:flex;min-height:calc(100vh - 60px)}
.kb-sidebar{width:300px;background:var(--color-surface);border-right:1px solid var(--color-border);overflow-y:auto;flex-shrink:0;display:flex;flex-direction:column}
.sidebar-header{padding:var(--space-4) var(--space-4) var(--space-3);border-bottom:1px solid var(--color-border)}
.sidebar-header h3{font-size:var(--font-size-xs);font-weight:700;color:var(--color-text);letter-spacing:0.3px;text-transform:uppercase}
.sidebar-header .kb-count{font-size:var(--font-size-xs);color:var(--color-text-muted);margin-top:2px}
.kb-sidebar .search-box{margin:var(--space-3) var(--space-4)}
.kb-sidebar .search-box input{width:100%;padding:var(--space-2) var(--space-3);border:1px solid var(--color-border-strong);border-radius:var(--radius-md);font-size:var(--font-size-sm);font-family:var(--font-sans);background:var(--color-surface);color:var(--color-text);transition:border-color var(--transition-fast),box-shadow var(--transition-fast)}
.kb-sidebar .search-box input:focus{outline:none;border-color:var(--color-primary);box-shadow:0 0 0 3px var(--color-primary-ring)}
.kb-sidebar .search-box input::placeholder{color:var(--color-text-muted)}
.kb-cat{margin-bottom:1px}
.kb-cat-header{padding:var(--space-2) var(--space-4);font-size:var(--font-size-xs);font-weight:600;color:var(--color-text-muted);cursor:pointer;display:flex;justify-content:space-between;align-items:center;text-transform:uppercase;letter-spacing:0.3px;user-select:none}
.kb-cat-header:hover{background:var(--color-bg)}
.kb-cat-header .arrow{transition:transform var(--transition-fast);font-size:10px;color:var(--color-text-muted)}
.kb-cat-header.active .arrow{transform:rotate(90deg)}
.kb-cat-items{display:none}
.kb-cat-items.open{display:block}
.kb-art{padding:var(--space-2) var(--space-4) var(--space-2) var(--space-6);font-size:var(--font-size-sm);color:var(--color-text-secondary);cursor:pointer;transition:all var(--transition-fast);border-left:3px solid transparent;line-height:var(--line-height-base);display:flex;align-items:center;gap:var(--space-2)}
.kb-art:hover{background:var(--color-bg)}
.kb-art.active{color:var(--color-primary);border-left-color:var(--color-primary);background:var(--color-primary-light);font-weight:600}
.kb-main{flex:1;overflow-y:auto;background:var(--color-surface)}
.kb-welcome{display:flex;flex-direction:column;align-items:center;justify-content:center;min-height:100%;padding:var(--space-16) var(--space-10);color:var(--color-text-muted);text-align:center}
.kb-welcome .welcome-icon{font-size:48px;margin-bottom:var(--space-4);opacity:0.6}
.kb-welcome h2{font-size:var(--font-size-xl);margin-bottom:var(--space-2);color:var(--color-text)}
.kb-welcome p{margin-bottom:var(--space-1);font-size:var(--font-size-sm)}
.kb-welcome .welcome-actions{margin-top:var(--space-5);display:flex;gap:var(--space-3)}

.reader{padding:var(--space-10) var(--space-12);max-width:var(--container-narrow);margin:0 auto}
.article-header{margin-bottom:var(--space-7)}
.article-header .article-meta{display:flex;align-items:center;gap:var(--space-2);margin-bottom:var(--space-3);font-size:var(--font-size-sm)}
.article-header h1{font-size:clamp(1.375rem,3vw,1.75rem);font-weight:700;line-height:1.3;color:var(--color-text);letter-spacing:-0.3px}
.article-body{color:var(--color-text-secondary);line-height:1.8;font-size:var(--font-size-base)}
.article-body h2{font-size:var(--font-size-xl);font-weight:700;margin:var(--space-7) 0 var(--space-3);padding-bottom:var(--space-2);border-bottom:1px solid var(--color-border);color:var(--color-text)}
.article-body h3{font-size:var(--font-size-lg);font-weight:600;margin:var(--space-6) 0 var(--space-3);color:var(--color-text)}
.article-body p{margin-bottom:var(--space-4)}
.article-body ul,.article-body ol{margin-bottom:var(--space-4);padding-left:var(--space-5)}
.article-body li{margin-bottom:var(--space-1);line-height:var(--line-height-relaxed)}
.article-body strong{color:var(--color-text)}
.article-body code{background:var(--color-primary-light);padding:2px 6px;border-radius:var(--radius-sm);font-family:var(--font-mono);font-size:var(--font-size-sm);color:var(--color-primary-dark)}
.article-body pre{background:#1e293b;color:#e2e8f0;padding:var(--space-5);border-radius:var(--radius-md);overflow-x:auto;margin-bottom:var(--space-5)}
.article-body pre code{background:none;color:inherit;padding:0;font-size:var(--font-size-sm)}
.article-body table{width:100%;border-collapse:collapse;margin-bottom:var(--space-5);font-size:var(--font-size-sm)}
.article-body th,.article-body td{border:1px solid var(--color-border);padding:var(--space-2) var(--space-3);text-align:left}
.article-body th{background:var(--color-bg);font-weight:600;color:var(--color-text)}
.article-body blockquote{border-left:3px solid var(--color-primary);padding:var(--space-3) var(--space-4);margin:var(--space-4) 0;background:var(--color-primary-light);border-radius:0 var(--radius-sm) var(--radius-sm) 0;color:var(--color-text-secondary);font-size:var(--font-size-sm)}
.article-body blockquote p{margin-bottom:0}
.article-body hr{border:none;border-top:1px solid var(--color-border);margin:var(--space-8) 0}
.article-body img{max-width:100%;border-radius:var(--radius-md);margin:var(--space-3) 0}

.chat-toggle{position:fixed;bottom:24px;right:24px;width:56px;height:56px;border-radius:50%;background:linear-gradient(135deg,var(--color-accent),var(--color-primary));color:#fff;border:none;font-size:24px;cursor:pointer;box-shadow:0 4px 16px rgba(34,197,94,0.35);z-index:1000;transition:all var(--transition-base);display:flex;align-items:center;justify-content:center}
.chat-toggle:hover{transform:scale(1.1);box-shadow:0 6px 24px rgba(34,197,94,0.45)}
.chat-toggle:active{transform:scale(0.95)}
.chat-panel{position:fixed;bottom:90px;right:24px;width:380px;height:520px;background:var(--color-surface);border-radius:var(--radius-lg);box-shadow:var(--shadow-xl);z-index:999;display:none;flex-direction:column;overflow:hidden;border:1px solid var(--color-border)}
.chat-panel.open{display:flex;animation:slideUp 0.3s ease}
@keyframes slideUp{from{opacity:0;transform:translateY(16px)}to{opacity:1;transform:translateY(0)}}
.chat-header{background:linear-gradient(135deg,var(--color-accent),var(--color-primary));color:#fff;padding:var(--space-4);font-weight:600;display:flex;justify-content:space-between;align-items:center;font-size:var(--font-size-sm)}
.chat-close{background:none;border:none;color:#fff;font-size:20px;cursor:pointer;padding:0 4px;opacity:0.8;transition:opacity var(--transition-fast)}
.chat-close:hover{opacity:1}
.chat-msgs{flex:1;padding:var(--space-4);overflow-y:auto;background:var(--color-bg);font-size:var(--font-size-sm)}
.chat-msg{margin-bottom:var(--space-3);max-width:85%;padding:var(--space-3) var(--space-4);border-radius:var(--radius-md);font-size:var(--font-size-sm);line-height:1.6;white-space:pre-wrap;word-wrap:break-word}
.chat-user{background:var(--color-primary);color:#fff;margin-left:auto;border-bottom-right-radius:4px}
.chat-ai{background:var(--color-surface);color:var(--color-text);border-bottom-left-radius:4px;box-shadow:var(--shadow-sm)}
.chat-input-area{display:flex;padding:var(--space-3);border-top:1px solid var(--color-border);background:var(--color-surface);gap:var(--space-2)}
.chat-input-area input{flex:1;padding:var(--space-3) var(--space-4);border:1px solid var(--color-border-strong);border-radius:var(--radius-full);font-size:var(--font-size-sm);outline:none;font-family:var(--font-sans);background:var(--color-bg);color:var(--color-text);transition:border-color var(--transition-fast)}
.chat-input-area input:focus{border-color:var(--color-primary)}
.chat-input-area input::placeholder{color:var(--color-text-muted)}
.chat-input-area button{padding:var(--space-3) var(--space-5);background:var(--color-primary);color:#fff;border:none;border-radius:var(--radius-full);cursor:pointer;font-size:var(--font-size-sm);font-weight:600;transition:background var(--transition-fast);white-space:nowrap}
.chat-input-area button:hover{background:var(--color-primary-dark)}
.chat-typing{color:var(--color-text-muted);font-size:var(--font-size-xs);padding:var(--space-2) var(--space-4)}

.admin-container{max-width:1000px;margin:var(--space-10) auto;padding:0 var(--space-5)}
.admin-container h2{margin-bottom:var(--space-6);color:var(--color-text)}
.admin-container h3{font-size:var(--font-size-lg);margin-bottom:var(--space-4);color:var(--color-text)}
.admin-stats{display:grid;grid-template-columns:repeat(auto-fill,minmax(240px,1fr));gap:var(--space-5);margin-bottom:var(--space-8)}
.admin-stat-card,.stat-card{background:var(--color-surface);border-radius:var(--radius-md);padding:var(--space-6);box-shadow:var(--shadow-sm);border:1px solid var(--color-border)}
.admin-stat-card h3{font-size:var(--font-size-sm);color:var(--color-text-muted);font-weight:500;margin-bottom:var(--space-2)}
.admin-stat-card .value,.stat-card .num{font-size:var(--font-size-2xl);font-weight:700;color:var(--color-text)}
.stat-card .label{font-size:var(--font-size-sm);color:var(--color-text-muted);margin-top:var(--space-1);display:block}
.stats-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:var(--space-4);margin-bottom:var(--space-8)}
.stat-card{text-align:center;padding:var(--space-5)}
.data-table{width:100%;border-collapse:collapse;background:var(--color-surface);border-radius:var(--radius-md);overflow:hidden;box-shadow:var(--shadow-sm);border:1px solid var(--color-border)}
.data-table th{background:var(--color-bg);padding:var(--space-3) var(--space-4);text-align:left;font-size:var(--font-size-xs);font-weight:600;color:var(--color-text-muted);text-transform:uppercase;letter-spacing:0.5px;border-bottom:1px solid var(--color-border)}
.data-table td{padding:var(--space-3) var(--space-4);font-size:var(--font-size-sm);border-bottom:1px solid var(--color-border);color:var(--color-text-secondary)}
.data-table tr:last-child td{border-bottom:none}
.data-table tr:hover td{background:var(--color-bg)}
.status-badge{padding:2px 10px;border-radius:var(--radius-full);font-size:var(--font-size-xs)}
.status-active{background:var(--color-primary-light);color:var(--color-primary-dark)}
.status-expired{background:#fef2f2;color:#dc2626}

.callout{padding:var(--space-4) var(--space-5);margin:var(--space-4) 0;border-radius:var(--radius-md);border-left:4px solid var(--color-primary);background:var(--color-primary-light);font-size:var(--font-size-sm)}
.callout-title{font-weight:700;margin-bottom:6px;display:flex;align-items:center;gap:6px}
.callout-info{border-color:#3b82f6;background:#eff6ff}
.callout-info .callout-title{color:#2563eb}
.callout-tip{border-color:var(--color-accent);background:var(--color-primary-light)}
.callout-tip .callout-title{color:var(--color-primary)}
.callout-warning{border-color:var(--color-gold);background:var(--color-gold-light)}
.callout-warning .callout-title{color:var(--color-gold-dark)}
.callout-danger{border-color:var(--color-danger);background:#fef2f2}
.callout-danger .callout-title{color:#dc2626}
.callout-important{border-color:#a855f7;background:#faf5ff}
.callout-important .callout-title{color:#9333ea}
.callout-seealso{border-color:#06b6d4;background:#ecfeff}
.callout-seealso .callout-title{color:#0891b2}
.callout-faq{border-color:#64748b;background:#f8fafc}
.callout-faq .callout-title{color:#475569}
.callout-example{border-color:#84cc16;background:#f7fee7}
.callout-example .callout-title{color:#65a30d}
.callout-question{border-color:#6366f1;background:#eef2ff}
.callout-question .callout-title{color:#4f46e5}
@media(prefers-color-scheme:dark){.callout-info{background:rgba(59,130,246,0.1)}.callout-tip{background:rgba(34,197,94,0.1)}.callout-warning{background:rgba(245,158,11,0.1)}.callout-danger{background:rgba(239,68,68,0.1)}.callout-important{background:rgba(168,85,247,0.1)}.callout-seealso{background:rgba(6,182,212,0.1)}.callout-faq{background:rgba(100,116,139,0.1)}.callout-example{background:rgba(132,204,22,0.1)}.callout-question{background:rgba(99,102,241,0.1)}}

.wikilink{color:var(--color-primary);text-decoration:none;border-bottom:1px dashed var(--color-primary);cursor:pointer;font-weight:500}
.wikilink:hover{background:var(--color-primary-light)}
.mermaid-placeholder{background:#1e293b;color:#e2e8f0;padding:var(--space-5);border-radius:var(--radius-md);text-align:center;font-family:var(--font-mono);font-size:var(--font-size-sm);margin:var(--space-4) 0;overflow-x:auto;white-space:pre;line-height:1.5}
.loading-spinner{display:flex;align-items:center;justify-content:center;padding:var(--space-16);color:var(--color-text-muted);font-size:var(--font-size-sm)}
.loading-spinner::before{content:'';width:20px;height:20px;border:2px solid var(--color-border);border-top-color:var(--color-primary);border-radius:50%;animation:spin 0.6s linear infinite;margin-right:var(--space-3)}
@keyframes spin{to{transform:rotate(360deg)}}
.preview-box{background:var(--color-surface);border:1px solid var(--color-border);border-radius:var(--radius-md);padding:var(--space-4) var(--space-5);margin-top:var(--space-4);text-align:left;font-size:var(--font-size-sm);color:var(--color-text-secondary)}
.preview-box h4{font-size:var(--font-size-base);font-weight:600;margin-bottom:var(--space-2);color:var(--color-text)}

@media(max-width:768px){
  .hero{padding:var(--space-12) 0 var(--space-10)}
  .hero-stats{gap:24px;flex-wrap:wrap}
  .hero-stat-num{font-size:var(--font-size-xl)}
  .pricing{flex-direction:column;align-items:center}
  .card{width:100%;max-width:400px}
  .grid{grid-template-columns:1fr}
  nav{gap:var(--space-3)}
  nav a{font-size:var(--font-size-xs)}
  .kb-layout{flex-direction:column}
  .kb-sidebar{width:100%;max-height:35vh;border-right:none;border-bottom:1px solid var(--color-border)}
  .reader{padding:var(--space-5) var(--space-4)}
  .container{padding:0 var(--space-4)}
  .chat-panel{width:calc(100% - 32px);right:16px;bottom:80px;height:460px}
  .stats-grid{grid-template-columns:1fr 1fr}
}
@media(max-width:480px){.stats-grid{grid-template-columns:1fr}}
@media(prefers-reduced-motion:reduce){*,*::before,*::after{animation-duration:0.01ms!important;animation-iteration-count:1!important;transition-duration:0.01ms!important;scroll-behavior:auto!important}
/* Category card images */
.cat-card-img {
  width: 100%;
  height: 140px;
  overflow: hidden;
  border-radius: 8px 8px 0 0;
  margin: -16px -16px 10px -16px;
}
.cat-card-img img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  transition: transform 0.3s ease;
}
.cat-card:hover .cat-card-img img {
  transform: scale(1.05);
}



/* Knowledge base - welcome covers */
.welcome-covers {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 16px;
  padding: 8px;
}
.welcome-cover {
  position: relative;
  border-radius: 10px;
  overflow: hidden;
  cursor: pointer;
  aspect-ratio: 2/1;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
  box-shadow: 0 2px 8px rgba(0,0,0,0.08);
}
.welcome-cover:hover {
  transform: translateY(-3px);
  box-shadow: 0 6px 20px rgba(0,0,0,0.15);
}
.welcome-cover img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}
.welcome-cover-overlay {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  padding: 10px 14px;
  background: linear-gradient(transparent, rgba(0,0,0,0.6));
  color: white;
  display: flex;
  justify-content: space-between;
  align-items: flex-end;
}
.welcome-cover-overlay span {
  font-size: 15px;
  font-weight: 600;
}
.welcome-cover-overlay small {
  font-size: 12px;
  opacity: 0.85;
}

/* Article page banner */
.article-banner {
  width: 100%;
  height: 140px;
  overflow: hidden;
  border-radius: 10px 10px 0 0;
  margin-bottom: 8px;
}
.article-banner img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

/* Category card images (index page) */
.cat-card-img {
  width: 100%;
  height: 130px;
  overflow: hidden;
  border-radius: 8px 8px 0 0;
  margin: -16px -16px 10px -16px;
}
.cat-card-img img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
  transition: transform 0.3s ease;
}
.cat-card:hover .cat-card-img img {
  transform: scale(1.05);
}



/* Embedded images in articles */
.embed-img {
  max-width: 100%;
  height: auto;
  border-radius: 8px;
  margin: 12px 0;
  display: block;
}



/* Chat source links */
.chat-msg.chat-ai .chat-text {
  line-height: 1.7;
  margin-bottom: 8px;
}
.chat-sources {
  margin-top: 10px;
  padding-top: 8px;
  border-top: 1px solid var(--color-border);
}
.chat-sources-label {
  display: block;
  font-size: 11px;
  color: var(--color-text-muted);
  margin-bottom: 4px;
  font-weight: 600;
}
.chat-source-link {
  display: inline-block;
  font-size: 12px;
  color: var(--color-primary);
  background: var(--color-primary-light);
  padding: 3px 10px;
  border-radius: 4px;
  margin: 2px 4px 2px 0;
  text-decoration: none;
  transition: background 0.2s;
  max-width: 100%;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
}
.chat-source-link:hover {
  background: var(--color-primary);
  color: white;
}

}

/* AI Promo Section */
.ai-promo {
  padding: 40px 0;
  background: var(--color-primary-light);
}
.ai-promo-card {
  display: flex;
  align-items: center;
  gap: 20px;
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 28px 32px;
  max-width: 720px;
  margin: 0 auto;
  box-shadow: var(--shadow-md);
}
.ai-promo-icon {
  font-size: 48px;
  flex-shrink: 0;
  background: var(--color-primary-light);
  width: 72px;
  height: 72px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
}
.ai-promo-card h3 {
  font-size: 18px;
  margin-bottom: 6px;
  color: var(--color-text);
}
.ai-promo-card p {
  font-size: 14px;
  color: var(--color-text-secondary);
  line-height: 1.7;
  margin: 0;
}
@media (max-width: 600px) {
  .ai-promo-card { flex-direction: column; text-align: center; padding: 24px 20px; }
}

/* ============ REDESIGNED HERO ============ */
.hero {
  background: linear-gradient(135deg, var(--color-hero-bg) 0%, #0a1a0f 100%);
  color: var(--color-hero-text);
  padding: 60px 0 0;
  position: relative;
  overflow: hidden;
}
.hero::before {
  content: "";
  position: absolute;
  top: -50%;
  right: -20%;
  width: 600px;
  height: 600px;
  background: radial-gradient(circle, rgba(34,197,94,0.08) 0%, transparent 70%);
  pointer-events: none;
}
.hero-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 48px;
  align-items: center;
  padding-bottom: 48px;
}
.hero-badge {
  display: inline-block;
  padding: 5px 14px;
  border-radius: var(--radius-full);
  font-size: 12px;
  font-weight: 600;
  background: rgba(34,197,94,0.15);
  color: var(--color-hero-accent);
  margin-bottom: 16px;
  letter-spacing: 0.5px;
}
.hero-text h1 {
  font-size: var(--font-size-hero);
  line-height: var(--line-height-tight);
  font-weight: 800;
  margin-bottom: 16px;
}
.hero-text h1 span {
  color: var(--color-hero-accent);
}
.hero-text p {
  font-size: var(--font-size-base);
  color: var(--color-hero-muted);
  max-width: 480px;
  line-height: 1.7;
  margin-bottom: 28px;
}
.hero-ctas {
  display: flex;
  gap: 12px;
  flex-wrap: wrap;
}
.btn-outline {
  display: inline-block;
  padding: 10px 24px;
  border-radius: var(--radius-md);
  font-size: 14px;
  font-weight: 600;
  border: 2px solid rgba(255,255,255,0.2);
  color: var(--color-hero-text);
  background: transparent;
  text-decoration: none;
  transition: all var(--transition-fast);
  cursor: pointer;
}
.btn-outline:hover {
  border-color: var(--color-hero-accent);
  color: var(--color-hero-accent);
  background: rgba(34,197,94,0.1);
}

/* Hero visual grid */
.hero-visual {
  position: relative;
}
.hero-visual-grid {
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  gap: 10px;
}
.hero-visual-item {
  aspect-ratio: 1;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 13px;
  font-weight: 600;
  color: white;
  cursor: default;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  position: relative;
  overflow: hidden;
}
.hero-visual-item::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, transparent 50%, rgba(0,0,0,0.3));
  pointer-events: none;
}
.hero-visual-item span {
  position: relative;
  z-index: 1;
}
.hero-visual-item:hover {
  transform: translateY(-4px) scale(1.03);
  box-shadow: 0 12px 32px rgba(0,0,0,0.3);
}
.hero-visual-cta {
  cursor: pointer;
  background: linear-gradient(135deg, #22c55e, #16a34a) !important;
}
.hero-visual-cta span {
  font-size: 15px;
}

/* Hero stats */
.hero-stats {
  background: rgba(255,255,255,0.04);
  border-top: 1px solid rgba(255,255,255,0.06);
  padding: 20px 0;
}
.hero-stats-inner {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 32px;
}
.hero-stat {
  text-align: center;
}
.hero-stat-num {
  display: block;
  font-size: 24px;
  font-weight: 800;
  color: var(--color-hero-accent);
  line-height: 1.2;
}
.hero-stat-label {
  font-size: 13px;
  color: var(--color-hero-muted);
}
.hero-stat-divider {
  width: 1px;
  height: 36px;
  background: rgba(255,255,255,0.1);
}

/* ============ FEATURES SECTION ============ */
.features {
  padding: 64px 0;
  background: var(--color-surface);
}
.features-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.feature-card {
  background: var(--color-bg);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  padding: 28px;
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  position: relative;
}
.feature-card:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-md);
}
.feature-card-accent {
  border-color: var(--color-gold-light);
  background: linear-gradient(135deg, var(--color-surface), #fffbeb);
}
.feature-badge {
  position: absolute;
  top: 12px;
  right: 12px;
  font-size: 11px;
  font-weight: 600;
  padding: 3px 10px;
  border-radius: var(--radius-full);
  background: var(--color-gold-light);
  color: var(--color-gold-dark);
}
.feature-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 16px;
}
.feature-card h3 {
  font-size: 17px;
  margin-bottom: 8px;
  color: var(--color-text);
}
.feature-card p {
  font-size: 13px;
  color: var(--color-text-muted);
  line-height: 1.6;
  margin: 0;
}

/* ============ RESPONSIVE ============ */
@media (max-width: 768px) {
  .hero-layout {
    grid-template-columns: 1fr;
    gap: 32px;
  }
  .hero-visual-grid {
    grid-template-columns: repeat(3, 1fr);
    max-width: 360px;
    margin: 0 auto;
  }
  .hero-visual-item {
    aspect-ratio: 1;
  }
  .features-grid {
    grid-template-columns: 1fr;
  }
  .hero-ctas {
    flex-direction: column;
  }
  .hero-ctas .btn {
    width: 100%;
    text-align: center;
  }
  .hero-stats-inner {
    gap: 16px;
  }
  .hero-stat-num {
    font-size: 20px;
  }
}
@media (max-width: 480px) {
  .hero {
    padding: 40px 0 0;
  }
  .hero-stats-inner {
    flex-wrap: wrap;
    gap: 12px;
  }
  .hero-stat-divider {
    display: none;
  }
}


/* ===== Homepage Design Improvements v2.5 ===== */

.hero {
  position: relative;
  overflow: hidden;
}

.hero::before {
  content: '';
  position: absolute;
  top: -50%;
  right: -20%;
  width: 500px;
  height: 500px;
  background: radial-gradient(circle, rgba(22,163,74,0.05) 0%, transparent 70%);
  border-radius: 50%;
  pointer-events: none;
}

.hero-badge {
  display: inline-block;
  background: rgba(22,163,74,0.1);
  color: var(--color-primary);
  padding: 6px 16px;
  border-radius: 100px;
  font-size: 13px;
  font-weight: 600;
  margin-bottom: 16px;
}

.hero-stats {
  margin-top: 48px;
  padding-top: 32px;
  border-top: 1px solid var(--color-border);
}

.hero-stats-inner {
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 24px;
}

.hero-stat {
  text-align: center;
}

.hero-stat-num {
  display: block;
  font-size: 28px;
  font-weight: 800;
  color: var(--color-text);
  line-height: 1.2;
}

.hero-stat-label {
  display: block;
  font-size: 13px;
  color: var(--color-text-muted);
  margin-top: 4px;
}

.hero-stat-divider {
  width: 1px;
  height: 40px;
  background: var(--color-border);
}

@media (max-width: 640px) {
  .hero-stats-inner {
    gap: 12px;
    flex-wrap: wrap;
  }
  .hero-stat-num {
    font-size: 22px;
  }
  .hero-stat-divider {
    display: none;
  }
}

/* Feature card hover improvement */
.feature-card {
  transition: all 0.3s ease;
}

.feature-card:hover {
  transform: translateY(-4px);
}

.feature-card-accent {
  border: 2px solid var(--color-gold);
}

/* Pricing section */
.pricing-section {
  background: var(--color-bg);
}

/* Better navigation */
nav a:hover {
  opacity: 0.8;
}

/* Admin stats grid */
.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(140px, 1fr));
  gap: 12px;
  margin-bottom: 24px;
}

.stat-card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-md);
  padding: 20px;
  text-align: center;
}

.stat-card .num {
  font-size: 32px;
  font-weight: 800;
  color: var(--color-primary);
  line-height: 1.2;
}

.stat-card .label {
  font-size: 13px;
  color: var(--color-text-muted);
  margin-top: 4px;
}

/* VIP badge - works in both light and dark mode */
.vip-badge {
  font-size: 13px !important;
  margin-top: 10px;
  font-weight: 700;
  display: inline-block;
  padding: 6px 14px;
  border-radius: 8px;
  color: #b91c1c;
  background: #fef2f2;
  border: 1px solid #fecaca;
}

@media (prefers-color-scheme: dark) {
  .vip-badge {
    color: #fca5a5;
    background: rgba(220,38,38,0.15);
    border: 1px solid rgba(220,38,38,0.3);
  }
}