* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
        }
        
        body {
            background: linear-gradient(135deg, #1a2a6c, #2c3e50, #4a6491);
            min-height: 100vh;
            padding: 20px;
            color: #333;
        }
        
        .container {
            max-width: 1200px;
            margin: 0 auto;
            background-color: rgba(255, 255, 255, 0.97);
            border-radius: 12px;
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
            overflow: hidden;
        }
        
        header {
            background: linear-gradient(to right, #2c3e50, #4a6491);
            color: white;
            padding: 20px;
            text-align: center;
            border-bottom: 1px solid #1a2a6c;
        }
        
        .header-content {
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 0 20px;
        }
        
        .logo {
            display: flex;
            align-items: center;
            gap: 15px;
        }
        
        .logo i {
            font-size: 32px;
            color: #4CAF50;
        }
        
        h1 {
            font-size: 28px;
            font-weight: 600;
            letter-spacing: 1px;
        }
        
        .date-controls {
            display: flex;
            align-items: center;
            gap: 15px;
            background: rgba(255, 255, 255, 0.15);
            padding: 10px 20px;
            border-radius: 30px;
        }
        
        .date-display {
            font-size: 18px;
            font-weight: 500;
        }
        
        .btn {
            background: #4CAF50;
            color: white;
            border: none;
            border-radius: 50%;
            width: 36px;
            height: 36px;
            cursor: pointer;
            font-size: 18px;
            display: flex;
            align-items: center;
            justify-content: center;
            transition: all 0.3s ease;
        }
        
        .btn:hover {
            background: #388E3C;
            transform: scale(1.05);
        }
        
        .main-content {
            display: flex;
            min-height: 600px;
        }
        
        .sidebar {
            width: 300px;
            background: #f5f5f5;
            border-right: 1px solid #ddd;
            padding: 20px;
            display: flex;
            flex-direction: column;
            gap: 25px;
        }
        
        .section {
            background: white;
            border-radius: 8px;
            padding: 20px;
            box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
        }
        
        .section h2 {
            margin-bottom: 20px;
            color: #2c3e50;
            border-bottom: 2px solid #4CAF50;
            padding-bottom: 10px;
            display: flex;
            align-items: center;
            gap: 10px;
        }
        
        .section h2 i {
            color: #4CAF50;
        }
        
        .form-group {
            margin-bottom: 20px;
        }
        
        .form-group label {
            display: block;
            margin-bottom: 8px;
            font-weight: 600;
            color: #2c3e50;
        }
        
        .form-control {
            width: 100%;
            padding: 12px;
            border: 1px solid #ddd;
            border-radius: 6px;
            font-size: 16px;
            transition: border-color 0.3s;
        }
        
        .form-control:focus {
            border-color: #4CAF50;
            outline: none;
            box-shadow: 0 0 0 2px rgba(76, 175, 80, 0.2);
        }
        
        select.form-control {
            appearance: none;
            background-image: url("data:image/svg+xml;charset=UTF-8,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='currentColor' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3e%3cpolyline points='6 9 12 15 18 9'%3e%3c/polyline%3e%3c/svg%3e");
            background-repeat: no-repeat;
            background-position: right 10px center;
            background-size: 16px;
        }
        
        .btn-primary {
            background: #4CAF50;
            color: white;
            border: none;
            border-radius: 6px;
            padding: 14px 20px;
            font-size: 16px;
            font-weight: 600;
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 10px;
            width: 100%;
            transition: all 0.3s ease;
        }
        
        .btn-primary:hover {
            background: #388E3C;
            transform: translateY(-2px);
            box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
        }
        
        .btn-primary i {
            font-size: 18px;
        }
        
        .btn-danger {
            background: #e74c3c;
            color: white;
            border: none;
            border-radius: 6px;
            padding: 14px 20px;
            font-size: 16px;
            font-weight: 600;
            cursor: pointer;
            display: flex;
            align-items: center;
            justify-content: center;
            gap: 10px;
            width: 100%;
            transition: all 0.3s ease;
        }
        
        .btn-danger:hover {
            background: #c0392b;
            transform: translateY(-2px);
            box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
        }
        
        .worksheet {
            flex: 1;
            padding: 20px;
            overflow: auto;
            background: #f9f9f9;
            display: flex;
            flex-direction: column;
            gap: 20px;
        }
        
        .section-title {
            display: flex;
            align-items: center;
            gap: 10px;
            margin-bottom: 15px;
        }
        
        .section-title i {
            color: #4CAF50;
            font-size: 24px;
        }
        
        .section-title h2 {
            color: #2c3e50;
        }
        
        .attendance-table {
            width: 100%;
            border-collapse: collapse;
            background: white;
            border-radius: 8px;
            overflow: hidden;
            box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
        }
        
        .attendance-table th {
            background: #2c3e50;
            color: white;
            font-weight: 600;
            text-align: left;
            padding: 15px;
        }
        
        .attendance-table td {
            padding: 15px;
            border-bottom: 1px solid #eee;
        }
        
        .attendance-table tr:nth-child(even) {
            background-color: #f8f9fa;
        }
        
        .attendance-table tr:hover {
            background-color: #e9f7fe;
        }
        
        .status-badge {
            padding: 6px 12px;
            border-radius: 20px;
            font-size: 14px;
            font-weight: 500;
        }
        
        .present-badge {
            background-color: #d4edda;
            color: #155724;
        }
        
        .absent-badge {
            background-color: #f8d7da;
            color: #721c24;
        }
        
        .btn-delete {
            background: #e74c3c;
            color: white;
            border: none;
            border-radius: 4px;
            padding: 8px 12px;
            cursor: pointer;
            transition: background 0.3s;
            display: flex;
            align-items: center;
            gap: 5px;
        }
        
        .btn-delete:hover {
            background: #c0392b;
        }
        
        .summary-table {
            width: 100%;
            border-collapse: collapse;
            background: white;
            border-radius: 8px;
            overflow: hidden;
            box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
        }
        
        .summary-table th, .summary-table td {
            padding: 15px;
            text-align: left;
        }
        
        .summary-table th {
            background: #4CAF50;
            color: white;
            font-weight: 600;
        }
        
        .summary-table tr:nth-child(even) {
            background-color: #f8f9fa;
        }
        
        .days-count {
            font-weight: 700;
            color: #2c3e50;
            font-size: 18px;
        }
        
        .week-pattern {
            display: flex;
            gap: 8px;
            margin-top: 10px;
        }
        
        .day-status {
            width: 30px;
            height: 30px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            font-weight: bold;
            font-size: 14px;
        }
        
        .day-present {
            background: #d4edda;
            color: #155724;
        }
        
        .day-absent {
            background: #f8d7da;
            color: #721c24;
        }
        
        .day-na {
            background: #f0f0f0;
            color: #666;
        }
        
        .footer {
            padding: 15px;
            text-align: center;
            background: #2c3e50;
            color: white;
            font-size: 14px;
            border-top: 1px solid #1a2a6c;
        }
        
        .week-dates {
            display: flex;
            justify-content: space-between;
            padding: 10px 0;
            font-weight: 500;
            color: #2c3e50;
        }
        
        .week-day {
            width: 30px;
            text-align: center;
            font-size: 12px;
        }
        
        .clear-data-container {
            margin-top: 20px;
            padding-top: 20px;
            border-top: 1px dashed #ccc;
        }
        
        .clear-warning {
            background-color: #fff8e1;
            border-left: 4px solid #ffc107;
            padding: 10px;
            margin-bottom: 15px;
            border-radius: 4px;
            font-size: 14px;
        }
        
        @media (max-width: 768px) {
            .main-content {
                flex-direction: column;
            }
            
            .sidebar {
                width: 100%;
                border-right: none;
                border-bottom: 1px solid #ddd;
            }
            
            .header-content {
                flex-direction: column;
                gap: 15px;
            }
            
            .week-pattern {
                gap: 4px;
            }
            
            .day-status {
                width: 25px;
                height: 25px;
                font-size: 12px;
            }
        }