*,*::before,*::after{box-sizing:border-box;margin:0;padding:0}
:root{--bg:#0F0F14;--surface:#1A1A24;--surface2:#242436;--text:#E8E8F0;--text-muted:#9898B0;--accent:#E85D4A;--accent2:#F5A623;--gold:#C8963E;--teal:#00CED1;--border:#2A2A3E;--radius:12px;--radius-sm:8px;--shadow:0 4px 24px rgba(0,0,0,.3);--font:-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,sans-serif;--max-width:1200px}
html{scroll-behavior:smooth}
body{font-family:var(--font);background:var(--bg);color:var(--text);line-height:1.6;-webkit-font-smoothing:antialiased}
.container{max-width:var(--max-width);margin:0 auto;padding:0 20px}
a{color:var(--accent);text-decoration:none}
a:hover{text-decoration:underline}
img{max-width:100%;height:auto}
button{font-family:var(--font);cursor:pointer}
label{display:block}
select{font-family:var(--font)}

.site-header{background:var(--surface);border-bottom:1px solid var(--border);position:sticky;top:0;z-index:100}
.site-header .container{display:flex;align-items:center;justify-content:space-between;height:64px;gap:16px}
.logo{display:flex;align-items:center;gap:10px;color:var(--text);font-size:1.1rem;text-decoration:none;white-space:nowrap}
.logo:hover{text-decoration:none}
.logo strong{color:var(--accent)}
.main-nav ul{display:flex;list-style:none;gap:4px}
.main-nav a{display:block;padding:8px 14px;border-radius:var(--radius-sm);color:var(--text-muted);font-size:.9rem;text-decoration:none;transition:all .2s}
.main-nav a:hover,.main-nav a.active{color:var(--text);background:var(--surface2)}
.main-nav a.active{background:var(--accent);color:#fff}
.menu-toggle{display:none;flex-direction:column;gap:4px;background:none;border:none;padding:4px}
.menu-toggle span{display:block;width:22px;height:2px;background:var(--text)}

.hero{padding:60px 0 40px;text-align:center}
.hero h1{font-size:clamp(1.8rem,4vw,2.8rem);font-weight:800;line-height:1.2;margin-bottom:16px;background:linear-gradient(135deg,var(--text),var(--accent));-webkit-background-clip:text;-webkit-text-fill-color:transparent;background-clip:text}
.hero-sub{font-size:1.1rem;color:var(--text-muted);max-width:640px;margin:0 auto 40px}
.era-timeline{display:flex;justify-content:center;flex-wrap:wrap;gap:8px;padding:20px 0}
.timeline-dot{display:flex;flex-direction:column;align-items:center;padding:12px 16px;background:var(--surface);border-radius:var(--radius);border:1px solid var(--border);min-width:80px;transition:all .2s}
.timeline-dot:hover{border-color:var(--accent);transform:translateY(-2px)}
.dot-year{font-size:.75rem;color:var(--text-muted);font-weight:600}
.dot-label{font-size:.8rem;color:var(--text);font-weight:700}

.section-intro{color:var(--text-muted);max-width:700px;margin-bottom:32px;font-size:1.05rem}
h2{font-size:1.8rem;margin-bottom:8px;font-weight:700}

.tab-content{display:none;padding:40px 0 60px}
.tab-content.active{display:block}

.filter-bar{margin-bottom:24px}
.filter-label{font-size:.9rem;color:var(--text-muted);margin-bottom:6px}
.filter-select{background:var(--surface2);color:var(--text);border:1px solid var(--border);padding:10px 16px;border-radius:var(--radius-sm);font-size:.95rem;cursor:pointer}
.filter-select:focus{outline:2px solid var(--accent);outline-offset:2px}

.era-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(340px,1fr));gap:24px}
.era-card{background:var(--surface);border-radius:var(--radius);border:1px solid var(--border);overflow:hidden;transition:all .3s}
.era-card:hover{border-color:var(--accent);box-shadow:var(--shadow);transform:translateY(-4px)}
.era-card-header{padding:24px 24px 20px;color:#fff}
.era-years{font-size:.8rem;opacity:.8;font-weight:600;text-transform:uppercase;letter-spacing:1px}
.era-card-header h3{font-size:1.3rem;margin-top:4px;font-weight:700}
.era-card-body{padding:20px 24px}
.era-tag{display:inline-block;padding:4px 12px;border-radius:20px;font-size:.75rem;font-weight:700;margin-bottom:16px}
.era-card-body h4{font-size:.85rem;text-transform:uppercase;letter-spacing:1px;color:var(--text-muted);margin:16px 0 8px;font-weight:600}
.era-card-body h4:first-of-type{margin-top:0}
.era-card-body ul{list-style:none;padding:0}
.era-card-body ul li{padding:4px 0;font-size:.9rem;color:var(--text-muted);padding-left:16px;position:relative}
.era-card-body ul li::before{content:"";position:absolute;left:0;top:10px;width:6px;height:6px;border-radius:50%;background:var(--accent);opacity:.6}
.era-card-body p{font-size:.9rem;color:var(--text-muted)}
.swatches{display:flex;gap:8px;margin:8px 0}
.swatches span{width:32px;height:32px;border-radius:50%;border:2px solid rgba(255,255,255,.15)}
.swatch-label{font-size:.8rem;color:var(--text-muted);margin-bottom:8px}

.quiz-area{max-width:700px;margin:0 auto}
.quiz-progress{margin-bottom:32px}
.progress-bar{height:8px;background:var(--surface);border-radius:4px;overflow:hidden;margin-bottom:8px}
.progress-fill{height:100%;background:linear-gradient(90deg,var(--accent),var(--accent2));border-radius:4px;transition:width .4s;width:12.5%}
.progress-text{font-size:.85rem;color:var(--text-muted)}
.quiz-prompt{font-size:1.15rem;font-weight:600;margin-bottom:24px;padding:24px;background:var(--surface);border-radius:var(--radius);border-left:4px solid var(--accent)}
.quiz-options{display:grid;gap:12px}
.quiz-option{padding:16px 20px;background:var(--surface2);border:2px solid var(--border);border-radius:var(--radius-sm);color:var(--text);font-size:1rem;text-align:left;transition:all .2s}
.quiz-option:hover{border-color:var(--accent);background:var(--surface)}
.quiz-option.correct{border-color:#2ECC71;background:rgba(46,204,113,.15)}
.quiz-option.wrong{border-color:#E74C3C;background:rgba(231,76,60,.15)}
.quiz-option:disabled{cursor:default}
.quiz-result{text-align:center;padding:40px 20px;background:var(--surface);border-radius:var(--radius)}
.quiz-result h3{font-size:1.5rem;margin-bottom:12px}
.hidden{display:none}

.compare-controls{display:flex;gap:24px;margin-bottom:32px;flex-wrap:wrap}
.compare-select-group{display:flex;flex-direction:column;gap:6px;flex:1;min-width:200px}
.compare-select-group label{font-size:.9rem;color:var(--text-muted);font-weight:600}
.compare-select-group select{background:var(--surface2);color:var(--text);border:1px solid var(--border);padding:10px 16px;border-radius:var(--radius-sm);font-size:.95rem}
.compare-grid{display:grid;grid-template-columns:1fr 1fr;gap:24px}
.compare-col{background:var(--surface);border-radius:var(--radius);border:1px solid var(--border);padding:24px;min-height:300px}
.compare-col h3{font-size:1.2rem;margin-bottom:4px}
.compare-col .cc-years{font-size:.85rem;color:var(--text-muted);margin-bottom:16px}
.compare-col .cc-label{display:inline-block;padding:3px 10px;border-radius:20px;font-size:.75rem;font-weight:700;margin-bottom:16px}
.compare-col h4{font-size:.8rem;text-transform:uppercase;letter-spacing:1px;color:var(--text-muted);margin:14px 0 6px}
.compare-col ul{list-style:none}
.compare-col ul li{font-size:.88rem;color:var(--text-muted);padding:3px 0 3px 14px;position:relative}
.compare-col ul li::before{content:"";position:absolute;left:0;top:9px;width:5px;height:5px;border-radius:50%;background:var(--accent);opacity:.6}
.compare-col .cc-swatches{display:flex;gap:6px;margin:6px 0 12px}
.compare-col .cc-swatches span{width:28px;height:28px;border-radius:50%;border:2px solid rgba(255,255,255,.15)}

.cheatsheet-actions{display:flex;gap:12px;margin-bottom:32px;flex-wrap:wrap}
.btn{padding:12px 24px;border-radius:var(--radius-sm);font-size:.95rem;font-weight:600;border:none;transition:all .2s}
.btn-primary{background:var(--accent);color:#fff}
.btn-primary:hover{background:#d14a38;transform:translateY(-1px)}
.btn-secondary{background:var(--surface2);color:var(--text);border:1px solid var(--border)}
.btn-secondary:hover{background:var(--surface);border-color:var(--accent)}
.cheatsheet-content{background:var(--surface);border-radius:var(--radius);border:1px solid var(--border);padding:32px}
.cs-section{margin-bottom:32px}
.cs-section:last-child{margin-bottom:0}
.cs-section h3{font-size:1.15rem;margin-bottom:16px;padding-bottom:8px;border-bottom:1px solid var(--border)}
.cs-flow{list-style:none;counter-reset:flow}
.cs-flow li{padding:10px 0 10px 48px;position:relative;font-size:.95rem;color:var(--text-muted);counter-increment:flow;border-bottom:1px solid var(--border)}
.cs-flow li:last-child{border-bottom:none}
.cs-flow li::before{content:counter(flow);position:absolute;left:0;top:8px;width:30px;height:30px;background:var(--accent);color:#fff;border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:.8rem;font-weight:700}
.cs-table{width:100%;border-collapse:collapse;font-size:.9rem}
.cs-table th,.cs-table td{padding:12px 16px;text-align:left;border-bottom:1px solid var(--border)}
.cs-table th{color:var(--text-muted);font-weight:600;font-size:.8rem;text-transform:uppercase;letter-spacing:1px}
.cs-table td{color:var(--text-muted)}
.cs-dl dt{font-weight:700;color:var(--text);margin-top:16px;font-size:.95rem}
.cs-dl dd{color:var(--text-muted);margin-top:4px;font-size:.9rem}

.reference-notes{padding:60px 0;background:var(--surface)}
.notes-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:20px;margin-bottom:40px}
.note-card{background:var(--bg);border-radius:var(--radius);border:1px solid var(--border);padding:24px}
.note-card h3{font-size:1rem;margin-bottom:8px;color:var(--accent)}
.note-card p{font-size:.9rem;color:var(--text-muted)}
.assumptions-box{background:var(--bg);border-radius:var(--radius);border:1px solid var(--border);padding:28px}
.assumptions-box h3{font-size:1.1rem;margin-bottom:12px}
.assumptions-box p{font-size:.9rem;color:var(--text-muted);margin-bottom:8px}
.last-updated{font-size:.8rem;color:var(--text-muted);margin-top:16px;padding-top:16px;border-top:1px solid var(--border)}

.site-footer{background:var(--surface);border-top:1px solid var(--border);margin-top:0}
.footer-top{display:flex;justify-content:space-between;align-items:flex-start;padding:40px 0 24px;gap:24px;flex-wrap:wrap}
.footer-brand p{font-size:.9rem;color:var(--text-muted);max-width:400px}
.footer-links{display:flex;gap:20px;flex-wrap:wrap}
.footer-links a{font-size:.9rem;color:var(--text-muted)}
.footer-links a:hover{color:var(--text)}
.footer-bottom{padding:20px 0;border-top:1px solid var(--border);text-align:center}
.footer-bottom p{font-size:.85rem;color:var(--text-muted)}
.footer-bottom a{color:var(--accent)}

@media(max-width:768px){
.main-nav{position:absolute;top:64px;left:0;right:0;background:var(--surface);border-bottom:1px solid var(--border);display:none}
.main-nav.open{display:block}
.main-nav ul{flex-direction:column;padding:12px 20px}
.main-nav a{padding:12px 16px}
.menu-toggle{display:flex}
.hero{padding:40px 0 30px}
.era-timeline{gap:4px}
.timeline-dot{min-width:60px;padding:8px 10px}
.dot-label{font-size:.7rem}
.era-grid{grid-template-columns:1fr}
.compare-grid{grid-template-columns:1px}
.compare-controls{flex-direction:column}
.compare-grid{grid-template-columns:1fr}
.cs-table{font-size:.8rem}
.cs-table th,.cs-table td{padding:8px 10px}
.footer-top{flex-direction:column}
}
@media print{
.site-header,.site-footer,.hero,.reference-notes,.cheatsheet-actions,.quiz-area,.compare-controls,.compare-grid,.filter-bar{display:none!important}
.tab-content{display:block!important}
body{background:#fff;color:#000}
.era-card{break-inside:avoid;border:1px solid #ccc}
}



/* Factory-injected deployment helpers. The AI owns the site design above this block. */
.ad-unit {
  width: min(100%, 720px);
  min-height: 120px;
  margin: 24px auto;
  display: block;
}

.legal-page {
  width: min(900px, calc(100% - 32px));
  margin: 40px auto;
}

.factory-fallback-nav {
  width: min(900px, calc(100% - 32px));
  margin: 24px auto 0;
  display: flex;
  flex-wrap: wrap;
  gap: 10px 16px;
  align-items: center;
  font-size: 0.95rem;
}

.factory-fallback-nav a {
  color: inherit;
  text-decoration: none;
  border-bottom: 1px solid currentColor;
}