:root {
    --primary-color: #2563eb;
    --primary-dark: #1d4ed8;
    --secondary-color: #64748b;
    --success-color: #10b981;
    --error-color: #ef4444;
    --warning-color: #f59e0b;
    --background-color: #f8fafc;
    --surface-color: #ffffff;
    --text-primary: #1e293b;
    --text-secondary: #64748b;
    --border-color: #e2e8f0;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
}

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

body {
    font-family: 'Inter', sans-serif;
    background-color: var(--background-color);
    color: var(--text-primary);
    line-height: 1.6;
}

.container {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

.header {
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
    color: white;
    padding: 2rem 0;
    text-align: center;
    box-shadow: var(--shadow);
}

.logo h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.logo p {
    font-size: 1.1rem;
    opacity: 0.9;
}

.main-content {
    flex: 1;
    padding: 2rem;
    display: flex;
    justify-content: center;
    align-items: flex-start;
}

.registration-form-container {
    background: var(--surface-color);
    border-radius: 12px;
    box-shadow: var(--shadow-lg);
    padding: 2rem;
    width: 100%;
    max-width: 800px;
}

.form-header {
    text-align: center;
    margin-bottom: 2rem;
    padding-bottom: 1rem;
    border-bottom: 1px solid var(--border-color);
}

.form-header h2 {
    color: var(--text-primary);
    margin-bottom: 0.5rem;
    font-weight: 600;
}

.form-header p {
    color: var(--text-secondary);
}

.form-section {
    margin-bottom: 2rem;
    padding-bottom: 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

.form-section:last-of-type {
    border-bottom: none;
}

.form-section h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-size: 1.2rem;
    font-weight: 600;
    display: flex;
    align-items: center;
}

.form-section h3::before {
    content: "\01F449";
    margin-right: 0.5rem;
    color: var(--primary-color);
}

.form-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

.form-group {
    display: flex;
    flex-direction: column;
}

.form-group.full-width {
    grid-column: 1 / -1;
}

label {
    font-weight: 500;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
    display: flex;
    align-items: center;
}

label::after {
    content: "*";
    color: var(--error-color);
    margin-left: 0.25rem;
}

input, select, textarea {
    padding: 0.75rem;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 1rem;
    transition: all 0.2s;
    font-family: inherit;
}

input:focus, select:focus, textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

small {
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin-top: 0.25rem;
}

.error-message {
    color: var(--error-color);
    font-size: 0.875rem;
    margin-top: 0.25rem;
    display: none;
}

.form-actions {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin-top: 2rem;
    padding-top: 1.5rem;
    border-top: 1px solid var(--border-color);
}

.btn {
    padding: 0.75rem 1.5rem;
    border: none;
    border-radius: 6px;
    font-size: 1rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
    text-decoration: none;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 120px;
}

.btn:disabled {
    opacity: 0.6;
    cursor: not-allowed;
}

.btn-primary {
    background-color: var(--primary-color);
    color: white;
}

.btn-primary:hover:not(:disabled) {
    background-color: var(--primary-dark);
    transform: translateY(-1px);
}

.btn-secondary {
    background-color: var(--secondary-color);
    color: white;
}

.btn-secondary:hover:not(:disabled) {
    background-color: #475569;
}

.notification {
    position: fixed;
    top: 20px;
    right: 20px;
    padding: 1rem 1.5rem;
    border-radius: 6px;
    color: white;
    font-weight: 500;
    box-shadow: var(--shadow-lg);
    z-index: 1000;
    max-width: 400px;
    animation: slideIn 0.3s ease-out;
}

.notification.success {
    background-color: var(--success-color);
}

.notification.error {
    background-color: var(--error-color);
}

.notification.warning {
    background-color: var(--warning-color);
}

.hidden {
    display: none;
}

.loading {
    opacity: 0.7;
    pointer-events: none;
}

.loading::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(255, 255, 255, 0.8);
    z-index: 10;
}

@keyframes slideIn {
    from {
        transform: translateX(100%);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

@media (max-width: 768px) {
    .main-content {
        padding: 1rem;
    }
    
    .registration-form-container {
        padding: 1.5rem;
    }
    
    .form-grid {
        grid-template-columns: 1fr;
    }
    
    .form-actions {
        flex-direction: column;
    }
    
    .btn {
        width: 100%;
    }
    
    .notification {
        left: 1rem;
        right: 1rem;
        max-width: none;
    }
}

/* Admin specific styles */
.admin-nav {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.admin-container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
}

.admin-stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: white;
    padding: 1.5rem;
    border-radius: 8px;
    box-shadow: var(--shadow);
    text-align: center;
}

.stat-card h3 {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.stat-card span {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-color);
}

.admin-controls {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
    gap: 1rem;
    flex-wrap: wrap;
}

.search-box {
    display: flex;
    gap: 0.5rem;
    align-items: center;
}

.search-box input {
    min-width: 300px;
}

.export-controls {
    display: flex;
    gap: 0.5rem;
}

.participants-table-container {
    background: white;
    border-radius: 8px;
    box-shadow: var(--shadow);
    overflow: hidden;
}

.participants-table {
    width: 100%;
    border-collapse: collapse;
}

.participants-table th,
.participants-table td {
    padding: 0.75rem 1rem;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.participants-table th {
    background: var(--background-color);
    font-weight: 600;
    color: var(--text-primary);
}

.participants-table tr:hover {
    background: #f8fafc;
}

.pagination {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1rem;
    padding: 1rem;
    background: var(--background-color);
}

.session-badge {
    background: #dbeafe;
    color: #1e40af;
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    font-size: 0.8rem;
    font-weight: 500;
}

.attendance-badge {
    background: #dcfce7;
    color: #166534;
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    font-size: 0.8rem;
    font-weight: 500;
}

.status-confirmed {
    color: var(--success-color);
    font-weight: 600;
}

.status-pending {
    color: var(--warning-color);
    font-weight: 600;
}

.btn-action {
    background: none;
    border: 1px solid var(--border-color);
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    cursor: pointer;
    margin: 0 0.125rem;
    font-size: 0.8rem;
}

.btn-action:hover {
    background: var(--background-color);
}

.btn-view {
    color: #2563eb;
}

.btn-email {
    color: #10b981;
}

.login-container {
    min-height: 100vh;
    display: flex;
    justify-content: center;
    align-items: center;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-dark));
}

.login-box {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: var(--shadow-lg);
    width: 100%;
    max-width: 400px;
}

.login-header {
    text-align: center;
    margin-bottom: 2rem;
}

.login-header h1 {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.login-form .form-group {
    margin-bottom: 1.5rem;
}

.login-actions {
    display: flex;
    flex-direction: column;
    gap: 1rem;
}

.btn-login {
    width: 100%;
}

/* Modal Styles */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    display: flex;
    justify-content: center;
    align-items: center;
    z-index: 2000;
}

.modal-content {
    background: white;
    border-radius: 8px;
    width: 90%;
    max-width: 800px;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: var(--shadow-lg);
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1.5rem;
    border-bottom: 1px solid var(--border-color);
}

.modal-header h2 {
    margin: 0;
    color: var(--text-primary);
}

.close-btn {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-secondary);
}

.close-btn:hover {
    color: var(--text-primary);
}

.modal-body {
    padding: 1.5rem;
}

.participant-details {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.detail-section h3 {
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-size: 1.1rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.5rem;
}

.detail-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

.detail-item {
    display: flex;
    flex-direction: column;
}

.detail-item.full-width {
    grid-column: 1 / -1;
}

.detail-item label {
    font-weight: 600;
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 0.25rem;
}

.detail-item span {
    padding: 0.5rem;
    background: var(--background-color);
    border-radius: 4px;
    border: 1px solid var(--border-color);
}

@media (max-width: 768px) {
    .detail-grid {
        grid-template-columns: 1fr;
    }
    
    .modal-content {
        width: 95%;
        margin: 1rem;
    }
}