:root{--primary: #6C3FE8;--primary-light: #8B6BF0;--primary-dark: #5230C4;--accent: #00D2A8;--accent2: #FF6B6B;--bg: #0F0E17;--surface: #1A1929;--surface-2: #222136;--border: rgba(255,255,255,.08);--text: #F0EFF8;--text-muted: rgba(240,239,248,.5);--text-faint: rgba(240,239,248,.3);--success: #22C55E;--danger: #EF4444;--warning: #F59E0B;--radius: 10px;--radius-lg: 16px;--radius-xl: 24px;--shadow: 0 4px 24px rgba(0,0,0,.4);--shadow-lg: 0 8px 48px rgba(0,0,0,.5);--transition: all .2s ease}*,*:before,*:after{box-sizing:border-box;margin:0;padding:0}html{scroll-behavior:smooth}body{font-family:Inter,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif;background:var(--bg);color:var(--text);line-height:1.6;min-height:100vh;overflow-x:hidden}a{color:inherit;text-decoration:none}button{cursor:pointer;font-family:inherit}input,select,textarea{font-family:inherit}img{max-width:100%}h1{font-size:clamp(1.8rem,4vw,3rem);font-weight:800;line-height:1.15}h2{font-size:clamp(1.4rem,3vw,2rem);font-weight:700;line-height:1.2}h3{font-size:1.2rem;font-weight:700}.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;padding:10px 22px;border-radius:var(--radius);font-weight:600;font-size:.9rem;border:none;transition:var(--transition);white-space:nowrap;letter-spacing:.01em}.btn:disabled{opacity:.5;cursor:not-allowed}.btn-primary{background:var(--primary);color:#fff}.btn-primary:hover:not(:disabled){background:var(--primary-dark);transform:translateY(-1px)}.btn-secondary{background:var(--surface-2);color:var(--text);border:1px solid var(--border)}.btn-secondary:hover:not(:disabled){border-color:var(--primary);color:var(--primary)}.btn-success{background:var(--success);color:#fff}.btn-danger{background:var(--danger);color:#fff}.btn-ghost{background:transparent;color:var(--text-muted);border:1px solid var(--border)}.btn-ghost:hover{color:var(--text);border-color:var(--text-muted)}.btn-lg{padding:14px 32px;font-size:1rem;border-radius:var(--radius-lg)}.btn-sm{padding:7px 14px;font-size:.82rem}.btn-block{width:100%}.btn-icon-only{padding:8px;border-radius:8px}.card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-lg);padding:24px}.card-hover{transition:var(--transition)}.card-hover:hover{transform:translateY(-3px);box-shadow:var(--shadow);border-color:#ffffff26}.form-group{margin-bottom:18px}.form-label{display:block;font-size:.85rem;font-weight:600;color:var(--text-muted);margin-bottom:7px;letter-spacing:.02em}.form-control{width:100%;background:var(--surface-2);border:1px solid var(--border);color:var(--text);border-radius:var(--radius);padding:11px 14px;font-size:.95rem;transition:var(--transition);outline:none}.form-control:focus{border-color:var(--primary);box-shadow:0 0 0 3px #6c3fe826}.form-control::placeholder{color:var(--text-faint)}.form-control.error{border-color:var(--danger)}.form-error{color:var(--danger);font-size:.82rem;margin-top:5px}.form-hint{color:var(--text-muted);font-size:.82rem;margin-top:5px}.badge{display:inline-flex;align-items:center;gap:5px;padding:3px 10px;border-radius:50px;font-size:.75rem;font-weight:700}.badge-primary{background:#6c3fe833;color:var(--primary-light)}.badge-success{background:#22c55e33;color:var(--success)}.badge-danger{background:#ef444433;color:var(--danger)}.badge-warning{background:#f59e0b33;color:var(--warning)}.progress-track{background:var(--surface-2);border-radius:50px;overflow:hidden;height:8px}.progress-fill{height:100%;border-radius:50px;background:linear-gradient(90deg,var(--primary),var(--accent));transition:width .6s ease}.lv-a1{background:#6bcb77}.lv-a2{background:#4ecdc4}.lv-b1{background:#45b7d1}.lv-b2{background:#8b6bf0}.lv-c1{background:#f5a623}.lv-c2{background:#ff5a5f}.level-chip{display:inline-flex;align-items:center;padding:3px 12px;border-radius:50px;font-size:.78rem;font-weight:700;color:#fff}.navbar{position:sticky;top:0;z-index:200;display:flex;align-items:center;justify-content:space-between;padding:0 32px;height:64px;background:#0f0e17d9;-webkit-backdrop-filter:blur(16px);backdrop-filter:blur(16px);border-bottom:1px solid var(--border)}.navbar-logo{font-size:1.3rem;font-weight:900;letter-spacing:-.02em}.navbar-logo span{color:var(--accent)}.navbar-links{display:flex;align-items:center;gap:8px}.navbar-link{color:var(--text-muted);padding:6px 12px;border-radius:8px;font-size:.9rem;transition:var(--transition)}.navbar-link:hover,.navbar-link.active{color:var(--text);background:var(--surface)}.app-layout{display:flex;min-height:calc(100vh - 64px)}.sidebar{width:240px;min-height:100%;background:var(--surface);border-right:1px solid var(--border);padding:16px 0;position:fixed;top:64px;left:0;bottom:0;display:flex;flex-direction:column;z-index:100;overflow-y:auto}.sidebar-section{padding:0 12px;margin-bottom:4px}.sidebar-label{font-size:.7rem;font-weight:700;color:var(--text-faint);text-transform:uppercase;letter-spacing:.08em;padding:10px 8px 4px}.sidebar-item{display:flex;align-items:center;gap:10px;padding:10px 12px;border-radius:var(--radius);color:var(--text-muted);font-size:.88rem;transition:var(--transition);border:none;background:none;width:100%;text-align:left;cursor:pointer}.sidebar-item:hover{background:var(--surface-2);color:var(--text)}.sidebar-item.active{background:#6c3fe826;color:var(--primary-light);font-weight:600}.sidebar-item .si-icon{font-size:1.1rem;width:22px;text-align:center;flex-shrink:0}.sidebar-item .si-badge{margin-left:auto;background:var(--primary);color:#fff;font-size:.68rem;font-weight:700;padding:1px 7px;border-radius:50px}.sidebar-user{margin:auto 12px 12px;background:var(--surface-2);border:1px solid var(--border);border-radius:var(--radius);padding:12px;display:flex;align-items:center;gap:10px}.sidebar-avatar{width:36px;height:36px;border-radius:50%;background:var(--primary);display:flex;align-items:center;justify-content:center;font-size:.9rem;font-weight:700;flex-shrink:0}.sidebar-user-info{flex:1;min-width:0}.sidebar-user-name{font-size:.85rem;font-weight:700;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.sidebar-user-level{font-size:.75rem;color:var(--text-muted)}.main-content{margin-left:240px;flex:1;padding:32px;min-width:0}.auth-page{min-height:100vh;display:flex;align-items:center;justify-content:center;padding:24px;background:var(--bg)}.auth-card{width:100%;max-width:440px;background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-xl);padding:40px}.auth-logo{text-align:center;font-size:1.6rem;font-weight:900;margin-bottom:6px}.auth-logo span{color:var(--accent)}.auth-subtitle{text-align:center;color:var(--text-muted);font-size:.9rem;margin-bottom:32px}.toast-container{position:fixed;bottom:24px;right:24px;z-index:9999;display:flex;flex-direction:column;gap:10px}.toast{background:var(--surface-2);border:1px solid var(--border);border-radius:var(--radius);padding:14px 18px;display:flex;align-items:center;gap:12px;box-shadow:var(--shadow);min-width:280px;max-width:380px;animation:slideIn .3s ease}.toast.success{border-left:3px solid var(--success)}.toast.error{border-left:3px solid var(--danger)}.toast.xp{border-left:3px solid var(--accent)}@keyframes slideIn{0%{transform:translate(100%);opacity:0}to{transform:translate(0);opacity:1}}.quiz-option{width:100%;background:var(--surface-2);border:1px solid var(--border);color:var(--text);border-radius:var(--radius);padding:13px 18px;text-align:left;font-size:.92rem;transition:var(--transition);margin-bottom:10px;display:block}.quiz-option:hover:not(:disabled){border-color:var(--primary);background:#6c3fe81a}.quiz-option.correct{border-color:var(--success);background:#22c55e1a;color:var(--success)}.quiz-option.wrong{border-color:var(--danger);background:#ef44441a;color:var(--danger)}.xp-bar-wrap{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);padding:16px 20px}.xp-bar-label{display:flex;justify-content:space-between;font-size:.82rem;color:var(--text-muted);margin-bottom:8px}.xp-bar-level{font-weight:700;color:var(--text);font-size:.9rem}.locked-overlay{position:absolute;top:0;right:0;bottom:0;left:0;background:#0f0e17bf;border-radius:inherit;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:8px;-webkit-backdrop-filter:blur(3px);backdrop-filter:blur(3px);z-index:10}.locked-icon{font-size:2rem}.locked-text{font-size:.82rem;color:var(--text-muted);text-align:center;padding:0 16px}.stats-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:16px}.stat-card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius-lg);padding:20px}.stat-icon{font-size:1.5rem;margin-bottom:8px}.stat-value{font-size:1.8rem;font-weight:800}.stat-label{font-size:.8rem;color:var(--text-muted);margin-top:2px}.mobile-bottom-nav{display:none;position:fixed;bottom:0;left:0;right:0;z-index:200;background:var(--surface);border-top:1px solid var(--border);padding:6px 0 env(safe-area-inset-bottom,6px)}.mobile-nav-item{flex:1;display:flex;flex-direction:column;align-items:center;gap:3px;padding:6px 4px;color:var(--text-muted);text-decoration:none;font-size:.68rem;font-weight:500;transition:color .2s}.mobile-nav-item.active{color:var(--primary-light)}.mobile-nav-icon{font-size:1.3rem;line-height:1}.mobile-nav-label{white-space:nowrap}@media (max-width: 1024px){.stats-grid{grid-template-columns:repeat(2,1fr)}}@media (max-width: 900px){.sidebar{display:none!important}.main-content{margin-left:0;padding:20px 16px 90px}.navbar{padding:0 16px}.navbar-links .navbar-link{display:none}.mobile-bottom-nav{display:flex}}@media (max-width: 600px){.stats-grid{grid-template-columns:1fr 1fr}.auth-card{padding:28px 20px}.main-content{padding:16px 12px 90px}}@keyframes fadeUp{0%{opacity:0;transform:translateY(16px)}to{opacity:1;transform:translateY(0)}}@keyframes pulse{0%,to{opacity:1}50%{opacity:.6}}@keyframes spin{to{transform:rotate(360deg)}}.fade-up{animation:fadeUp .4s ease both}.loader{width:40px;height:40px;border:3px solid var(--border);border-top-color:var(--primary);border-radius:50%;animation:spin .8s linear infinite}.page-loader{display:flex;align-items:center;justify-content:center;min-height:60vh}