:root{--primary: #6c5ce7;--primary-light: #a29bfe;--secondary: #00cec9;--accent: #fd79a8;--warning: #fdcb6e;--success: #00b894;--danger: #e17055;--bg-dark: #1a1a2e;--bg-card: #16213e;--bg-sidebar: #0f3460;--text-primary: #ffffff;--text-secondary: #b8c5d6;--text-muted: #8395a7;--border: rgba(255, 255, 255, .08);--radius: 16px;--radius-sm: 10px;--shadow: 0 8px 32px rgba(0, 0, 0, .3);font-family:Segoe UI,system-ui,-apple-system,sans-serif;line-height:1.5}*{box-sizing:border-box;margin:0;padding:0}html,body,#root{min-height:100vh;background:var(--bg-dark);color:var(--text-primary)}.app-layout{display:flex;min-height:100vh}.sidebar{width:260px;background:var(--bg-sidebar);padding:24px 16px;display:flex;flex-direction:column;gap:8px;position:fixed;top:0;left:0;bottom:0;z-index:100;overflow-y:auto;transition:transform .3s ease}.sidebar-logo{display:flex;align-items:center;gap:12px;padding:8px 12px;margin-bottom:24px}.sidebar-logo .logo-icon{width:44px;height:44px;background:linear-gradient(135deg,var(--primary),var(--accent));border-radius:14px;display:grid;place-items:center;font-size:22px}.sidebar-logo h2{font-size:1.25rem;font-weight:700;background:linear-gradient(135deg,var(--primary-light),var(--accent));-webkit-background-clip:text;-webkit-text-fill-color:transparent}.nav-item{display:flex;align-items:center;gap:12px;padding:12px 16px;border-radius:var(--radius-sm);cursor:pointer;color:var(--text-secondary);font-size:.9rem;font-weight:500;transition:all .2s;border:none;background:none;width:100%;text-align:left}.nav-item:hover{background:#ffffff14;color:var(--text-primary)}.nav-item.active{background:linear-gradient(135deg,var(--primary),#5a4bd1);color:#fff;box-shadow:0 4px 15px #6c5ce766}.nav-section-label{font-size:.7rem;text-transform:uppercase;letter-spacing:.1em;color:var(--text-muted);padding:16px 16px 4px;font-weight:600}.main-content{flex:1;margin-left:260px;padding:32px;min-height:100vh}.page-header{margin-bottom:32px}.page-header h1{font-size:2rem;font-weight:800;margin-bottom:6px;background:linear-gradient(135deg,var(--text-primary),var(--primary-light));-webkit-background-clip:text;-webkit-text-fill-color:transparent}.page-header p{color:var(--text-secondary);font-size:1rem}.card{background:var(--bg-card);border-radius:var(--radius);padding:24px;border:1px solid var(--border);transition:transform .2s,box-shadow .2s}.card:hover{transform:translateY(-2px);box-shadow:var(--shadow)}.card-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(280px,1fr));gap:20px}.stats-row{display:grid;grid-template-columns:repeat(auto-fill,minmax(220px,1fr));gap:16px;margin-bottom:32px}.stat-card{background:var(--bg-card);border-radius:var(--radius);padding:20px;border:1px solid var(--border);display:flex;align-items:center;gap:16px}.stat-icon{width:52px;height:52px;border-radius:14px;display:grid;place-items:center;flex-shrink:0}.stat-icon.purple{background:#6c5ce733;color:var(--primary-light)}.stat-icon.teal{background:#00cec933;color:var(--secondary)}.stat-icon.pink{background:#fd79a833;color:var(--accent)}.stat-icon.yellow{background:#fdcb6e33;color:var(--warning)}.stat-info h3{font-size:1.5rem;font-weight:700}.stat-info p{font-size:.8rem;color:var(--text-muted)}.btn{display:inline-flex;align-items:center;gap:8px;padding:10px 20px;border-radius:var(--radius-sm);font-weight:600;font-size:.9rem;cursor:pointer;border:none;transition:all .2s}.btn-primary{background:linear-gradient(135deg,var(--primary),#5a4bd1);color:#fff;box-shadow:0 4px 15px #6c5ce74d}.btn-primary:hover{box-shadow:0 6px 20px #6c5ce780;transform:translateY(-1px)}.btn-secondary{background:#ffffff14;color:var(--text-primary);border:1px solid var(--border)}.btn-secondary:hover{background:#ffffff1f}.btn-accent{background:linear-gradient(135deg,var(--accent),#e84393);color:#fff}.btn-success{background:linear-gradient(135deg,var(--success),#00a381);color:#fff}.btn-warning{background:linear-gradient(135deg,var(--warning),#f9b234);color:#2d3436}.btn-sm{padding:6px 14px;font-size:.8rem}.btn-lg{padding:14px 28px;font-size:1rem}.form-group{margin-bottom:20px}.form-group label{display:block;font-size:.85rem;font-weight:600;color:var(--text-secondary);margin-bottom:6px}.form-input,.form-textarea,.form-select{width:100%;padding:12px 16px;background:#ffffff0d;border:1px solid var(--border);border-radius:var(--radius-sm);color:var(--text-primary);font-size:.95rem;transition:border-color .2s;font-family:inherit}.form-input:focus,.form-textarea:focus,.form-select:focus{outline:none;border-color:var(--primary);box-shadow:0 0 0 3px #6c5ce733}.form-textarea{resize:vertical;min-height:120px}.form-select{-webkit-appearance:none;-moz-appearance:none;appearance:none;cursor:pointer;background-image:url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='12' height='12' fill='%23b8c5d6' viewBox='0 0 16 16'%3E%3Cpath d='M8 11L3 6h10z'/%3E%3C/svg%3E");background-repeat:no-repeat;background-position:right 12px center}.upload-area{border:2px dashed rgba(108,92,231,.4);border-radius:var(--radius);padding:48px;text-align:center;cursor:pointer;transition:all .2s;background:#6c5ce70d}.upload-area:hover{border-color:var(--primary);background:#6c5ce71a}.upload-area .icon{margin-bottom:12px;color:var(--primary-light)}.upload-area h3{margin-bottom:4px}.upload-area p{color:var(--text-muted);font-size:.85rem}.badge{display:inline-flex;align-items:center;padding:4px 12px;border-radius:20px;font-size:.75rem;font-weight:600}.badge-purple{background:#6c5ce733;color:var(--primary-light)}.badge-teal{background:#00cec933;color:var(--secondary)}.badge-pink{background:#fd79a833;color:var(--accent)}.badge-yellow{background:#fdcb6e33;color:var(--warning)}.badge-green{background:#00b89433;color:var(--success)}.progress-bar{height:8px;background:#ffffff14;border-radius:4px;overflow:hidden}.progress-fill{height:100%;border-radius:4px;transition:width .5s ease}.progress-fill.purple{background:linear-gradient(90deg,var(--primary),var(--primary-light))}.progress-fill.teal{background:linear-gradient(90deg,var(--secondary),#55efc4)}.progress-fill.pink{background:linear-gradient(90deg,var(--accent),#fab1a0)}.progress-fill.green{background:linear-gradient(90deg,var(--success),#55efc4)}.guide-card{background:var(--bg-card);border-radius:var(--radius);padding:24px;border:1px solid var(--border);cursor:pointer;transition:all .2s}.guide-card:hover{transform:translateY(-2px);box-shadow:var(--shadow);border-color:var(--primary)}.guide-card .guide-icon{width:48px;height:48px;border-radius:12px;display:grid;place-items:center;margin-bottom:16px;font-size:22px}.guide-card h3{font-size:1.05rem;margin-bottom:6px}.guide-card p{color:var(--text-muted);font-size:.85rem;margin-bottom:12px}.video-card{background:var(--bg-card);border-radius:var(--radius);overflow:hidden;border:1px solid var(--border);transition:all .2s;cursor:pointer}.video-card:hover{transform:translateY(-2px);box-shadow:var(--shadow)}.video-thumbnail{width:100%;aspect-ratio:16/9;display:grid;place-items:center;position:relative}.video-thumbnail .play-icon{width:56px;height:56px;background:#0009;border-radius:50%;display:grid;place-items:center;-webkit-backdrop-filter:blur(4px);backdrop-filter:blur(4px)}.video-card .video-info{padding:16px}.video-card .video-info h3{font-size:.95rem;margin-bottom:4px}.video-card .video-info p{color:var(--text-muted);font-size:.8rem}.group-card{background:var(--bg-card);border-radius:var(--radius);padding:24px;border:1px solid var(--border)}.group-card .group-header{display:flex;justify-content:space-between;align-items:flex-start;margin-bottom:12px}.group-card .members-row{display:flex;align-items:center;gap:8px;margin-top:16px}.member-avatar{width:32px;height:32px;border-radius:50%;display:grid;place-items:center;font-size:.75rem;font-weight:700;border:2px solid var(--bg-card)}.member-avatar+.member-avatar{margin-left:-10px}.quiz-question{background:var(--bg-card);border-radius:var(--radius);padding:32px;border:1px solid var(--border);margin-bottom:24px}.quiz-question h3{font-size:1.1rem;margin-bottom:20px}.quiz-options{display:flex;flex-direction:column;gap:10px}.quiz-option{display:flex;align-items:center;gap:12px;padding:14px 18px;background:#ffffff0a;border:1px solid var(--border);border-radius:var(--radius-sm);cursor:pointer;transition:all .2s;color:var(--text-primary);font-size:.95rem;width:100%;text-align:left}.quiz-option:hover{background:#6c5ce71a;border-color:var(--primary)}.quiz-option.selected{background:#6c5ce726;border-color:var(--primary)}.quiz-option.correct{background:#00b89433;border-color:#00b894;box-shadow:0 0 0 1px #00b89466}.quiz-option.incorrect{background:#e1705533;border-color:#e17055;box-shadow:0 0 0 1px #e1705566}.quiz-option .option-letter{width:30px;height:30px;border-radius:8px;display:grid;place-items:center;font-weight:700;font-size:.85rem;flex-shrink:0;background:#ffffff14}.quiz-option.selected .option-letter{background:var(--primary);color:#fff}.quiz-option.correct .option-letter{background:var(--success);color:#fff}.quiz-option.incorrect .option-letter{background:var(--danger);color:#fff}.quiz-progress{display:flex;align-items:center;gap:16px;margin-bottom:24px}.quiz-progress .progress-text{font-size:.85rem;color:var(--text-muted);white-space:nowrap}.quiz-result{text-align:center;padding:48px 32px}.quiz-result .score-circle{width:140px;height:140px;border-radius:50%;display:grid;place-items:center;margin:0 auto 24px;font-size:2.5rem;font-weight:800}.progress-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(320px,1fr));gap:20px}.subject-progress{background:var(--bg-card);border-radius:var(--radius);padding:24px;border:1px solid var(--border)}.subject-progress .subject-header{display:flex;justify-content:space-between;align-items:center;margin-bottom:16px}.subject-progress .subject-stats{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;margin-top:16px}.subject-progress .stat-mini{text-align:center}.subject-progress .stat-mini .value{font-size:1.2rem;font-weight:700}.subject-progress .stat-mini .label{font-size:.7rem;color:var(--text-muted)}.achievement-card{display:flex;align-items:center;gap:16px;background:var(--bg-card);border-radius:var(--radius);padding:16px 20px;border:1px solid var(--border)}.achievement-card .achievement-icon{width:48px;height:48px;border-radius:50%;display:grid;place-items:center;font-size:22px;flex-shrink:0}.achievement-card.locked{opacity:.5}.achievement-card h4{font-size:.95rem;margin-bottom:2px}.achievement-card p{font-size:.8rem;color:var(--text-muted)}.parental-card{background:var(--bg-card);border-radius:var(--radius);padding:24px;border:1px solid var(--border)}.parental-card .toggle-row{display:flex;align-items:center;justify-content:space-between;padding:12px 0;border-bottom:1px solid var(--border)}.parental-card .toggle-row:last-child{border-bottom:none}.toggle-switch{width:48px;height:26px;background:#ffffff26;border-radius:13px;cursor:pointer;position:relative;transition:background .2s;border:none;flex-shrink:0}.toggle-switch.active{background:var(--success)}.toggle-switch:after{content:"";position:absolute;width:20px;height:20px;background:#fff;border-radius:50%;top:3px;left:3px;transition:transform .2s}.toggle-switch.active:after{transform:translate(22px)}.activity-item{display:flex;align-items:flex-start;gap:12px;padding:12px 0;border-bottom:1px solid var(--border)}.activity-item:last-child{border-bottom:none}.activity-dot{width:8px;height:8px;border-radius:50%;margin-top:6px;flex-shrink:0}.activity-item .time{font-size:.75rem;color:var(--text-muted);margin-top:2px}.question-card{background:var(--bg-card);border-radius:var(--radius);padding:24px;border:1px solid var(--border);margin-bottom:16px}.question-card .question-meta{display:flex;align-items:center;gap:12px;margin-top:12px}.tabs{display:flex;gap:4px;background:#ffffff0a;padding:4px;border-radius:var(--radius-sm);margin-bottom:24px;overflow-x:auto}.tab{padding:10px 20px;border-radius:8px;cursor:pointer;font-size:.85rem;font-weight:600;color:var(--text-secondary);transition:all .2s;white-space:nowrap;border:none;background:none}.tab:hover{color:var(--text-primary)}.tab.active{background:var(--primary);color:#fff}.modal-overlay{position:fixed;top:0;right:0;bottom:0;left:0;background:#000000b3;display:grid;place-items:center;z-index:200;padding:20px;-webkit-backdrop-filter:blur(4px);backdrop-filter:blur(4px)}.modal{background:var(--bg-card);border-radius:var(--radius);padding:32px;max-width:560px;width:100%;max-height:90vh;overflow-y:auto;border:1px solid var(--border)}.modal h2{margin-bottom:20px}.guide-detail{max-width:800px}.guide-detail .guide-content{background:var(--bg-card);border-radius:var(--radius);padding:32px;border:1px solid var(--border);line-height:1.8}.guide-detail .guide-content h3{margin:20px 0 8px;color:var(--primary-light)}.guide-detail .guide-content ul{padding-left:20px}.guide-detail .guide-content li{margin-bottom:6px;color:var(--text-secondary)}.mobile-menu-btn{display:none;position:fixed;top:16px;left:16px;z-index:150;width:44px;height:44px;background:var(--bg-card);border:1px solid var(--border);border-radius:12px;color:#fff;cursor:pointer;place-items:center}@media(max-width:768px){.mobile-menu-btn{display:grid}.sidebar{transform:translate(-100%)}.sidebar.open{transform:translate(0)}.main-content{margin-left:0;padding:72px 16px 24px}.stats-row{grid-template-columns:1fr 1fr}.card-grid,.progress-grid{grid-template-columns:1fr}}@keyframes fadeIn{0%{opacity:0;transform:translateY(10px)}to{opacity:1;transform:translateY(0)}}.fade-in{animation:fadeIn .3s ease}.safety-banner{background:linear-gradient(135deg,#00b89426,#00cec91a);border:1px solid rgba(0,184,148,.3);border-radius:var(--radius);padding:16px 20px;display:flex;align-items:center;gap:12px;margin-bottom:24px;font-size:.9rem;color:var(--secondary)}.homework-item{display:flex;align-items:center;gap:16px;background:var(--bg-card);border-radius:var(--radius);padding:16px 20px;border:1px solid var(--border);margin-bottom:12px;transition:all .2s}.homework-item:hover{border-color:var(--primary)}.homework-item .hw-icon{width:44px;height:44px;border-radius:12px;display:grid;place-items:center;flex-shrink:0}.homework-item .hw-info{flex:1}.homework-item .hw-info h4{font-size:.95rem;margin-bottom:2px}.homework-item .hw-info p{font-size:.8rem;color:var(--text-muted)}::-webkit-scrollbar{width:6px}::-webkit-scrollbar-track{background:transparent}::-webkit-scrollbar-thumb{background:#ffffff1a;border-radius:3px}::-webkit-scrollbar-thumb:hover{background:#fff3}