* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
}

header {
    background: white;
    padding: 20px;
    border-radius: 10px;
    margin-bottom: 20px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

header h1 {
    color: #667eea;
    font-size: 28px;
}

.user-info {
    font-weight: bold;
    color: #555;
}

.section {
    animation: fadeIn 0.5s;
}

.hidden {
    display: none !important;
}

.card {
    background: white;
    padding: 30px;
    border-radius: 10px;
    box-shadow: 0 4px 6px rgba(0, 0, 0, 0.1);
}

.card h2 {
    color: #333;
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid #667eea;
}

.card h3 {
    color: #555;
    margin-top: 30px;
    margin-bottom: 15px;
}

.form-group {
    margin-bottom: 15px;
}

.form-group label {
    display: block;
    margin-bottom: 5px;
    color: #555;
    font-weight: 500;
}

.form-group input {
    width: 100%;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-size: 14px;
}

.form-group input:focus {
    outline: none;
    border-color: #667eea;
}

.form-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 15px;
}

.btn {
    padding: 10px 20px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    transition: all 0.3s;
}

.btn-primary {
    background: #667eea;
    color: white;
}

.btn-primary:hover {
    background: #5568d3;
}

.btn-success {
    background: #48bb78;
    color: white;
}

.btn-success:hover {
    background: #38a169;
}

.btn-danger {
    background: #f56565;
    color: white;
}

.btn-danger:hover {
    background: #e53e3e;
}

.btn-secondary {
    background: #718096;
    color: white;
}

.btn-secondary:hover {
    background: #4a5568;
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.btn-sm {
    padding: 5px 10px;
    font-size: 12px;
}

.error-message {
    background: #fed7d7;
    color: #742a2a;
    padding: 10px;
    border-radius: 5px;
    margin-top: 10px;
    border-left: 4px solid #f56565;
}

.success-message {
    background: #c6f6d5;
    color: #22543d;
    padding: 10px;
    border-radius: 5px;
    margin-top: 10px;
    border-left: 4px solid #48bb78;
}

.info-box {
    background: #f7fafc;
    border-left: 4px solid #667eea;
    padding: 15px;
    margin-top: 20px;
    border-radius: 5px;
}

.info-box p {
    margin: 5px 0;
    color: #555;
    font-size: 14px;
}

.welcome-msg {
    background: #e6fffa;
    border-left: 4px solid #48bb78;
    padding: 15px;
    margin-bottom: 20px;
    border-radius: 5px;
    font-weight: 500;
    color: #2d3748;
}

.attendance-controls {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
    flex-wrap: wrap;
}

.status-box {
    background: #fff5f5;
    border-left: 4px solid #f56565;
    padding: 15px;
    margin-bottom: 20px;
    border-radius: 5px;
    font-weight: 500;
}

.status-box.checked-in {
    background: #f0fff4;
    border-left-color: #48bb78;
}

.attendance-list {
    margin-top: 20px;
}

.attendance-item {
    background: #f7fafc;
    padding: 15px;
    margin-bottom: 10px;
    border-radius: 5px;
    border-left: 4px solid #667eea;
}

.attendance-item.incomplete {
    border-left-color: #f6ad55;
}

.admin-tabs {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
    border-bottom: 2px solid #e2e8f0;
}

.tab-btn {
    padding: 10px 20px;
    background: none;
    border: none;
    cursor: pointer;
    font-size: 14px;
    font-weight: 500;
    color: #718096;
    border-bottom: 2px solid transparent;
    margin-bottom: -2px;
    transition: all 0.3s;
}

.tab-btn.active {
    color: #667eea;
    border-bottom-color: #667eea;
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
}

.table-container {
    overflow-x: auto;
}

table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 10px;
}

table th,
table td {
    padding: 12px;
    text-align: left;
    border-bottom: 1px solid #e2e8f0;
}

table th {
    background: #f7fafc;
    font-weight: 600;
    color: #2d3748;
}

table tr:hover {
    background: #f7fafc;
}

.badge {
    display: inline-block;
    padding: 4px 8px;
    border-radius: 12px;
    font-size: 12px;
    font-weight: 500;
}

.badge-success {
    background: #c6f6d5;
    color: #22543d;
}

.badge-warning {
    background: #feebc8;
    color: #744210;
}

.filter-group {
    display: flex;
    gap: 10px;
    align-items: center;
    margin-bottom: 20px;
    flex-wrap: wrap;
}

.filter-group label {
    font-weight: 500;
    color: #555;
}

.filter-group input {
    padding: 8px;
    border: 1px solid #ddd;
    border-radius: 5px;
}

.spinner {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 9999;
}

.spinner-border {
    width: 50px;
    height: 50px;
    border: 5px solid #f3f3f3;
    border-top: 5px solid #667eea;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@media (max-width: 768px) {
    header {
        flex-direction: column;
        gap: 10px;
    }

    .form-row {
        grid-template-columns: 1fr;
    }

    .attendance-controls {
        flex-direction: column;
    }

    .attendance-controls .btn {
        width: 100%;
    }
}