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button.active{background:#ffffff1f}.sidebar .spacer{flex:1}.sidebar .user-info{opacity:.5;word-break:break-all;font-size:12px}.main{flex:1;min-width:0;margin-left:240px;padding:32px 40px}.main h1{margin-bottom:24px;font-size:24px}.card{background:var(--surface);border:1px solid var(--border);border-radius:var(--radius);margin-bottom:16px;padding:20px}.card-header{justify-content:space-between;align-items:center;margin-bottom:12px;display:flex}.card-header h3{font-size:16px}.btn{border-radius:var(--radius);cursor:pointer;border:none;align-items:center;gap:6px;padding:8px 16px;font-size:14px;font-weight:500;transition:background .15s;display:inline-flex}.btn-primary{background:var(--primary);color:#fff}.btn-primary:hover{background:var(--primary-hover)}.btn-danger{background:var(--danger);color:#fff}.btn-danger:hover{background:var(--danger-hover)}.btn-ghost{color:var(--text-secondary);background:0 0}.btn-ghost:hover{background:var(--bg)}.btn-sm{padding:4px 10px;font-size:12px}.form-group{margin-bottom:16px}.form-group label{color:var(--text-secondary);margin-bottom:4px;font-size:13px;font-weight:600;display:block}.form-group input,.form-group textarea,.form-group select{border:1px solid var(--border);border-radius:var(--radius);width:100%;padding:10px 12px;font-family:inherit;font-size:14px;transition:border-color .15s}.form-group input:focus,.form-group textarea:focus,.form-group select:focus{border-color:var(--primary);outline:none}.form-group textarea{resize:vertical;min-height:200px;font-family:SF Mono,Fira Code,monospace;font-size:13px}.form-row{grid-template-columns:1fr 1fr;gap:16px;display:grid}.table{border-collapse:collapse;width:100%}.table th,.table td{text-align:left;border-bottom:1px solid var(--border);padding:12px;font-size:14px}.table th{text-transform:uppercase;color:var(--text-secondary);letter-spacing:.5px;font-size:12px}.table tr:hover td{background:var(--bg)}.badge{text-transform:uppercase;border-radius:12px;padding:2px 8px;font-size:11px;font-weight:600;display:inline-block}.badge-category{color:#6d28d9;background:#ede9fe}.badge-count{color:#0369a1;background:#e0f2fe}.badge-role-user{color:#475569;background:#f1f5f9}.badge-role-teacher{color:#15803d;background:#dcfce7}.badge-role-admin{color:#b45309;background:#fef3c7}.badge-sub-active{color:#15803d;background:#dcfce7}.badge-sub-inactive{color:#9ca3af;background:#f1f5f9}.users-table-wrap{overflow-x:auto}.expanded-row td{background:var(--bg)!important;padding:0!important}.user-detail-grid{grid-template-columns:repeat(auto-fill,minmax(200px,1fr));gap:8px 16px;padding:16px 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0;border:none;border-bottom:2px solid #0000;margin-bottom:-2px;padding:10px 20px;font-size:14px;font-weight:500}.tab-btn.active{border-bottom-color:var(--primary);color:var(--primary)}.login-page{background:var(--bg);justify-content:center;align-items:center;min-height:100vh;display:flex}.login-box{background:var(--surface);text-align:center;border-radius:12px;width:100%;max-width:400px;padding:48px;box-shadow:0 4px 24px #00000014}.login-box h1{margin-bottom:8px}.login-box p{color:var(--text-secondary);margin-bottom:24px}.login-box .form-group{text-align:left}.login-error{color:var(--danger);margin-bottom:12px;font-size:13px}.empty{text-align:center;color:var(--text-secondary);padding:48px}.empty p{margin-bottom:16px}.actions{gap:8px;display:flex}.mt-16{margin-top:16px}.text-sm{color:var(--text-secondary);font-size:13px}