*{margin:0;padding:0;box-sizing:border-box}:root{--primary: #1890ff;--primary-hover: #40a9ff;--success: #52c41a;--warning: #faad14;--danger: #ff4d4f;--text: #333;--text-secondary: #666;--bg: #f5f5f5;--bg-white: #fff;--border: #d9d9d9;--shadow: 0 2px 8px rgba(0,0,0,.08);--radius: 8px}body{font-family:-apple-system,BlinkMacSystemFont,Segoe UI,PingFang SC,Hiragino Sans GB,Microsoft YaHei,Helvetica Neue,Helvetica,Arial,sans-serif;color:var(--text);background-color:var(--bg);line-height:1.6;min-height:100vh}#root{width:100%;min-height:100vh}a{color:var(--primary);text-decoration:none}a:hover{color:var(--primary-hover)}.app-layout{display:flex;min-height:100vh}.sidebar{width:220px;background:#001529;color:#fff;padding:0;position:fixed;top:0;left:0;bottom:0;overflow-y:auto;z-index:100}.sidebar-logo{height:64px;display:flex;align-items:center;justify-content:center;font-size:18px;font-weight:600;color:#fff;border-bottom:1px solid rgba(255,255,255,.1)}.sidebar-menu{list-style:none;padding:8px 0}.sidebar-menu li{padding:12px 24px;cursor:pointer;transition:all .3s;display:flex;align-items:center;gap:10px;font-size:14px}.sidebar-menu li:hover{background:rgba(255,255,255,.08)}.sidebar-menu li.active{background:var(--primary)}.sidebar-menu .menu-group-title{padding:16px 24px 8px;font-size:12px;color:#ffffff73;cursor:default;text-transform:uppercase}.sidebar-menu .menu-group-title:hover{background:transparent}.main-content{margin-left:220px;flex:1;min-height:100vh;display:flex;flex-direction:column}.top-header{height:64px;background:var(--bg-white);display:flex;align-items:center;justify-content:space-between;padding:0 24px;box-shadow:var(--shadow);position:sticky;top:0;z-index:50}.top-header .user-info{display:flex;align-items:center;gap:12px}.page-container{padding:24px;flex:1}.card{background:var(--bg-white);border-radius:var(--radius);box-shadow:var(--shadow);padding:24px;margin-bottom:16px}.card-title{font-size:16px;font-weight:600;margin-bottom:16px;padding-bottom:12px;border-bottom:1px solid var(--border)}.btn{display:inline-flex;align-items:center;justify-content:center;padding:8px 16px;border-radius:6px;font-size:14px;cursor:pointer;border:1px solid var(--border);background:var(--bg-white);color:var(--text);transition:all .3s;gap:6px}.btn:hover{border-color:var(--primary);color:var(--primary)}.btn-primary{background:var(--primary);color:#fff;border-color:var(--primary)}.btn-primary:hover{background:var(--primary-hover);border-color:var(--primary-hover);color:#fff}.btn-danger{background:var(--danger);color:#fff;border-color:var(--danger)}.btn-danger:hover{opacity:.85}.btn-success{background:var(--success);color:#fff;border-color:var(--success)}.btn-sm{padding:4px 12px;font-size:12px}.btn-lg{padding:12px 24px;font-size:16px}.btn-outline{background:#fff;color:var(--primary);border:1px solid var(--primary)}.btn-outline:hover{background:var(--primary);color:#fff}.form-group{margin-bottom:16px}.form-group label{display:block;margin-bottom:6px;font-size:14px;font-weight:500;color:var(--text)}.form-control{width:100%;padding:8px 12px;border:1px solid var(--border);border-radius:6px;font-size:14px;transition:border-color .3s;outline:none}.form-control:focus{border-color:var(--primary);box-shadow:0 0 0 2px #1890ff33}select.form-control{-webkit-appearance:auto;-moz-appearance:auto;appearance:auto}.table-container{overflow-x:auto}table{width:100%;border-collapse:collapse}table th,table td{padding:12px 16px;text-align:left;border-bottom:1px solid #f0f0f0;font-size:14px}table th{background:#fafafa;font-weight:600;color:var(--text-secondary)}table tr:hover{background:#fafafa}.tag{display:inline-block;padding:2px 8px;border-radius:4px;font-size:12px}.tag-success{background:#f6ffed;color:var(--success);border:1px solid #b7eb8f}.tag-danger{background:#fff2f0;color:var(--danger);border:1px solid #ffccc7}.tag-primary{background:#e6f7ff;color:var(--primary);border:1px solid #91d5ff}.tag-warning{background:#fffbe6;color:#d48806;border:1px solid #ffe58f}.tag-info{background:#e6f7ff;color:#1890ff;border:1px solid #91d5ff}.auth-container{min-height:100vh;display:flex;align-items:center;justify-content:center;background:linear-gradient(135deg,#667eea 0%,#764ba2 100%)}.auth-card{background:var(--bg-white);border-radius:12px;padding:40px;width:400px;box-shadow:0 20px 60px #00000026}.auth-card h2{text-align:center;margin-bottom:8px;font-size:24px;color:var(--text)}.auth-card .subtitle{text-align:center;color:var(--text-secondary);margin-bottom:32px;font-size:14px}.auth-card .form-group{margin-bottom:20px}.auth-card .btn-primary{width:100%;padding:12px;font-size:16px}.auth-card .auth-footer{text-align:center;margin-top:16px;font-size:14px}.quiz-container{max-width:800px;margin:0 auto}.quiz-question{background:var(--bg-white);border-radius:var(--radius);padding:24px;margin-bottom:16px;box-shadow:var(--shadow)}.quiz-question h3{margin-bottom:16px;font-size:16px}.quiz-option{display:flex;align-items:center;padding:12px 16px;border:1px solid var(--border);border-radius:6px;margin-bottom:8px;cursor:pointer;transition:all .3s}.quiz-option:hover{border-color:var(--primary);background:#e6f7ff}.quiz-option.selected{border-color:var(--primary);background:#e6f7ff;color:var(--primary)}.quiz-option.correct{border-color:var(--success);background:#f6ffed;color:var(--success)}.quiz-option.wrong{border-color:var(--danger);background:#fff2f0;color:var(--danger)}.quiz-option input{margin-right:12px}.quiz-question img,.card img{max-width:100%;height:auto;display:block;margin:8px 0;border-radius:4px}.quiz-question span img{display:inline-block;vertical-align:middle;max-height:200px}.quiz-option span img{max-height:120px;vertical-align:middle}.ranking-item{display:flex;align-items:center;padding:12px 16px;background:var(--bg-white);border-radius:var(--radius);margin-bottom:8px;box-shadow:var(--shadow)}.ranking-rank{width:40px;height:40px;border-radius:50%;display:flex;align-items:center;justify-content:center;font-weight:600;font-size:16px;margin-right:16px;background:#f0f0f0}.ranking-rank.top1{background:#ffd700;color:#fff}.ranking-rank.top2{background:#c0c0c0;color:#fff}.ranking-rank.top3{background:#cd7f32;color:#fff}.ranking-info{flex:1}.ranking-name{font-weight:500}.ranking-district{font-size:12px;color:var(--text-secondary)}.ranking-score{font-size:20px;font-weight:600;color:var(--primary)}.message-item{background:var(--bg-white);border-radius:var(--radius);padding:16px;margin-bottom:12px;box-shadow:var(--shadow)}.message-header{display:flex;justify-content:space-between;margin-bottom:8px;font-size:12px;color:var(--text-secondary)}.message-content{font-size:14px;line-height:1.8}.message-reply{margin-left:24px;padding:12px;background:#fafafa;border-radius:6px;margin-top:8px}.stats-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(200px,1fr));gap:16px;margin-bottom:24px}.stat-card{background:var(--bg-white);border-radius:var(--radius);padding:20px;box-shadow:var(--shadow);text-align:center}.stat-card .stat-value{font-size:28px;font-weight:600;color:var(--primary)}.stat-card .stat-label{font-size:14px;color:var(--text-secondary);margin-top:4px}.modal-overlay{position:fixed;top:0;left:0;right:0;bottom:0;background:rgba(0,0,0,.45);display:flex;align-items:center;justify-content:center;z-index:1000}.modal{background:var(--bg-white);border-radius:var(--radius);padding:24px;min-width:400px;max-width:600px;max-height:80vh;overflow-y:auto}.modal-title{font-size:18px;font-weight:600;margin-bottom:16px}.modal-footer{display:flex;justify-content:flex-end;gap:8px;margin-top:16px}.pagination{display:flex;align-items:center;justify-content:center;gap:8px;margin-top:16px}.pagination .btn{min-width:36px}.pagination .btn.active{background:var(--primary);color:#fff;border-color:var(--primary)}.empty-state{text-align:center;padding:48px;color:var(--text-secondary)}.empty-state .icon{font-size:48px;margin-bottom:16px}.alert{padding:12px 16px;border-radius:6px;margin-bottom:16px;font-size:14px}.alert-success{background:#f6ffed;border:1px solid #b7eb8f;color:var(--success)}.alert-error{background:#fff2f0;border:1px solid #ffccc7;color:var(--danger)}.alert-info{background:#e6f7ff;border:1px solid #91d5ff;color:var(--primary)}@media (max-width: 768px){.sidebar{width:0;overflow:hidden}.main-content{margin-left:0}.stats-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}.spinner{display:inline-block;width:20px;height:20px;border:2px solid #f0f0f0;border-top:2px solid var(--primary);border-radius:50%;animation:spin 1s linear infinite}@keyframes spin{0%{transform:rotate(0)}to{transform:rotate(360deg)}}.loading{display:flex;align-items:center;justify-content:center;padding:48px;gap:12px;color:var(--text-secondary)}