:root{--primary: #a3734f;--primary-light: #f0ebe3;--accent: #c8970a;--bg: #fdfcfb;--text: #3d2b1f;--text-muted: #6b5a4a;--shadow: rgba(163, 115, 79, .12);--radius-lg: 32px;--radius-md: 16px}*{box-sizing:border-box;margin:0;padding:0}body{background:var(--bg);color:var(--text);font-family:"Source Han Serif SC","Noto Serif SC",Georgia,serif;overflow-x:hidden}.app-shell{min-height:100vh;display:flex;flex-direction:column;position:relative;perspective:1200px}.bg-glow{position:fixed;top:50%;left:50%;transform:translate(-50%,-50%);width:80vw;height:80vh;background:radial-gradient(circle,rgba(163,115,79,.05) 0%,transparent 70%);pointer-events:none;z-index:-1}.glass-header{padding:1.25rem 2.5rem;display:flex;justify-content:space-between;align-items:center;background:#fdfcfbd9;-webkit-backdrop-filter:blur(12px);backdrop-filter:blur(12px);border-bottom:1px solid rgba(163,115,79,.1);position:sticky;top:0;z-index:100}.brand{display:flex;align-items:center;gap:1rem;cursor:pointer}.brand-icon{width:44px;height:44px;background:var(--primary);border-radius:14px;display:flex;align-items:center;justify-content:center;color:#fff;box-shadow:0 4px 12px var(--shadow)}.brand-info h1{font-size:1.2rem;font-weight:800;letter-spacing:1px}.sync-status{font-size:.7rem;color:var(--accent);display:flex;align-items:center;gap:4px;font-family:sans-serif}.nav-link{display:flex;align-items:center;gap:8px;padding:.6rem 1.2rem;border-radius:20px;border:1px solid transparent;background:var(--primary-light);color:var(--text);font-weight:600;font-size:.9rem;cursor:pointer;transition:.3s}.nav-link:hover{border-color:var(--primary);background:#fff}.nav-link.active{background:var(--primary);color:#fff}.main-stage{flex:1;max-width:1100px;margin:0 auto;padding:3rem 1.5rem;width:100%}.welcome-hero{text-align:center;margin-bottom:4rem}.kicker{font-size:.85rem;font-weight:700;color:var(--accent);text-transform:uppercase;letter-spacing:2px;margin-bottom:1rem;display:block}.welcome-hero h2{font-size:3rem;margin-bottom:1rem;color:var(--text)}.sub-text{font-size:1.1rem;color:var(--text-muted);font-style:italic}.era-showcase{display:grid;grid-template-columns:repeat(auto-fit,minmax(320px,1fr));gap:2rem}.era-card{background:#fff;border:2px solid var(--primary-light);border-radius:var(--radius-lg);padding:2rem;cursor:pointer;transition:all .4s cubic-bezier(.175,.885,.32,1.275);position:relative;overflow:hidden}.era-card:before{content:"";position:absolute;top:0;left:0;width:100%;height:6px;background:var(--primary)}.era-card-top{display:flex;justify-content:space-between;align-items:center;margin-bottom:1.5rem}.era-index{font-family:monospace;font-weight:900;color:var(--primary-light);font-size:2rem}.era-tag{font-size:.75rem;font-weight:700;color:var(--accent);background:#c8970a1a;padding:4px 12px;border-radius:12px}.era-card h3{font-size:1.8rem;margin-bottom:1rem}.era-desc{font-size:.95rem;color:var(--text-muted);line-height:1.7;margin-bottom:2rem}.guide-pill{display:flex;align-items:center;gap:8px;background:var(--primary-light);padding:4px 12px;border-radius:20px;font-size:.8rem;font-weight:600}.avatar{width:24px;height:24px;background:var(--primary);color:#fff;border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:.7rem}.era-card-bottom{display:flex;justify-content:space-between;align-items:center}.explore-layout{display:grid;grid-template-columns:1.6fr 1fr;gap:3rem}.art-frame{aspect-ratio:16/9;background:#eee;border-radius:var(--radius-md);border:8px solid white;box-shadow:0 10px 30px var(--shadow);margin:2rem 0;display:flex;align-items:center;justify-content:center;background:linear-gradient(45deg,#f0ebe3,#fdfcfb)}.era-quote{font-size:1.2rem;font-style:italic;color:var(--primary);border-left:4px solid var(--primary);padding-left:1.5rem;margin:2rem 0}.btn-primary-large{width:100%;padding:1.25rem;background:var(--primary);color:#fff;border:none;border-radius:var(--radius-md);font-size:1.1rem;font-weight:700;cursor:pointer;display:flex;align-items:center;justify-content:center;gap:12px;transition:.3s}.btn-primary-large:hover{transform:translateY(-3px);box-shadow:0 8px 20px #a3734f4d}.character-card{background:#fff;padding:2rem;border-radius:var(--radius-md);border:2px solid var(--primary-light)}.char-avatar{width:64px;height:64px;background:var(--primary);color:#fff;border-radius:50%;display:flex;align-items:center;justify-content:center;font-size:1.5rem;margin-bottom:1rem}.speech-bubble{margin-top:1.5rem;background:var(--primary-light);padding:1.5rem;border-radius:20px;position:relative;font-size:.95rem;line-height:1.6}.quiz-box{background:#fff;border-radius:var(--radius-lg);padding:3rem;border:2px solid var(--primary-light);box-shadow:0 30px 60px var(--shadow)}.quiz-header{margin-bottom:2.5rem}.quiz-info{display:flex;justify-content:space-between;margin-bottom:1rem;font-weight:700;color:var(--text-muted)}.progress-track{height:8px;background:var(--primary-light);border-radius:4px;overflow:hidden}.progress-fill{height:100%;background:var(--primary)}.quiz-question{font-size:2.2rem;margin-bottom:2.5rem;line-height:1.4}.options-list{display:grid;gap:1.25rem}.option-item{display:flex;align-items:center;gap:1.5rem;padding:1.5rem;border-radius:var(--radius-md);border:2px solid var(--primary-light);background:#fff;text-align:left;cursor:pointer;transition:.2s}.option-item:hover:not(:disabled){border-color:var(--primary);background:var(--primary-light)}.opt-num{width:32px;height:32px;border-radius:50%;background:var(--primary-light);display:flex;align-items:center;justify-content:center;font-weight:800;font-size:.8rem}.key-hint{margin-left:auto;font-size:.7rem;opacity:.4;font-family:sans-serif}.option-item.correct{border-color:#10b981;background:#ecfdf5}.option-item.wrong{border-color:#ef4444;background:#fef2f2}.option-item.dim{opacity:.4}.feedback-area{margin-top:2.5rem;padding-top:2.5rem;border-top:2px dashed var(--primary-light)}.explanation{background:var(--primary-light);padding:1.5rem;border-radius:var(--radius-md);margin-bottom:1.5rem}.exp-header{font-weight:800;font-size:.85rem;margin-bottom:.5rem;display:flex;align-items:center;gap:6px;color:var(--primary)}.cert-paper{background:#fff;padding:1.5rem;border-radius:4px;box-shadow:0 20px 50px var(--shadow);max-width:600px;margin:0 auto 3rem}.cert-border{border:6px double var(--primary);padding:3rem;text-align:center;position:relative}.cert-seal{width:80px;height:80px;color:var(--accent);margin-bottom:2rem;filter:drop-shadow(0 4px 8px rgba(200,151,10,.3))}.cert-title{font-size:2.2rem;letter-spacing:4px;margin-bottom:1.5rem;color:var(--primary)}.cert-stats{display:flex;justify-content:space-around;margin:2.5rem 0;padding:1.5rem 0;border-top:1px solid var(--primary-light);border-bottom:1px solid var(--primary-light)}.stat-item b{display:block;font-size:1.8rem;color:var(--primary)}.stat-item span{font-size:.75rem;color:var(--text-muted);font-weight:700}.loading-container{height:100vh;display:flex;flex-direction:column;align-items:center;justify-content:center;background:var(--bg)}.loading-text{margin:2rem 0 1rem;font-size:1.5rem;color:var(--primary)}.loading-bar{width:240px;height:6px;background:var(--primary-light);border-radius:3px;overflow:hidden}.loading-progress{height:100%;background:var(--primary)}.app-footer{padding:3rem;text-align:center;font-size:.8rem;color:var(--text-muted);opacity:.6}@media (max-width: 850px){.explore-layout{grid-template-columns:1fr}.welcome-hero h2{font-size:2rem}}