/* Reset and base styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f4f4f4;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

/* Header styles */
header {
    text-align: center;
    margin-bottom: 40px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 30px;
    border-radius: 10px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
}

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

/* Search section styles */
.search-section {
    background: white;
    padding: 25px;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    margin-bottom: 30px;
}

.search-section h2 {
    margin-bottom: 20px;
    color: #333;
    font-size: 1.8rem;
}

.search-controls {
    display: flex;
    gap: 15px;
    align-items: center;
    flex-wrap: wrap;
}

#searchInput {
    flex: 1;
    padding: 12px 15px;
    border: 2px solid #ddd;
    border-radius: 8px;
    font-size: 16px;
    transition: border-color 0.3s ease;
    min-width: 250px;
}

#searchInput:focus {
    outline: none;
    border-color: #667eea;
}

#sortBy {
    padding: 12px 15px;
    border: 2px solid #ddd;
    border-radius: 8px;
    font-size: 16px;
    background: white;
    cursor: pointer;
    transition: border-color 0.3s ease;
}

#sortBy:focus {
    outline: none;
    border-color: #667eea;
}

/* Button styles */
.btn {
    padding: 12px 24px;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
    display: inline-block;
    text-align: center;
}

.btn-primary {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
}

.btn-secondary {
    background: #6c757d;
    color: white;
}

.btn-secondary:hover {
    background: #5a6268;
    transform: translateY(-2px);
}

.btn-edit {
    background: #28a745;
    color: white;
    padding: 8px 16px;
    font-size: 14px;
}

.btn-edit:hover {
    background: #218838;
}

.btn-delete {
    background: #dc3545;
    color: white;
    padding: 8px 16px;
    font-size: 14px;
}

.btn-delete:hover {
    background: #c82333;
}

/* Students section styles */
.students-section {
    background: white;
    padding: 25px;
    border-radius: 10px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.students-section h2 {
    margin-bottom: 20px;
    color: #333;
    font-size: 1.8rem;
}

.students-count {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 20px;
    color: #667eea;
}

/* Table styles */
.table-container {
    overflow-x: auto;
}

.students-table {
    width: 100%;
    border-collapse: collapse;
    background: white;
    border-radius: 8px;
    overflow: hidden;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

.students-table thead {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.students-table th,
.students-table td {
    padding: 15px;
    text-align: left;
    border-bottom: 1px solid #eee;
}

.students-table th {
    font-weight: 600;
    font-size: 14px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.students-table tbody tr {
    transition: background-color 0.3s ease;
}

.students-table tbody tr:hover {
    background-color: #f8f9fa;
}

.students-table td {
    font-size: 14px;
}

.table-actions {
    display: flex;
    gap: 10px;
}

/* Empty state */
.empty-state {
    text-align: center;
    padding: 60px 20px;
    color: #666;
}

.empty-state.hidden {
    display: none;
}

.empty-state h3 {
    font-size: 1.5rem;
    margin-bottom: 10px;
    color: #999;
}

.empty-state p {
    font-size: 1rem;
    color: #bbb;
}

/* Modal styles */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.5);
    animation: fadeIn 0.3s ease;
    overflow-y: auto;
    padding: 20px 0;
}

.modal-content {
    background-color: white;
    margin: 0 auto;
    padding: 0;
    border-radius: 10px;
    width: 90%;
    max-width: 600px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
    animation: slideIn 0.3s ease;
    position: relative;
    max-height: calc(100vh - 40px);
    display: flex;
    flex-direction: column;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 25px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border-radius: 10px 10px 0 0;
    flex-shrink: 0;
}

.modal-header h2 {
    margin: 0;
    font-size: 1.5rem;
}

.close {
    color: white;
    font-size: 28px;
    font-weight: bold;
    cursor: pointer;
    transition: opacity 0.3s ease;
}

.close:hover {
    opacity: 0.7;
}

.modal-body {
    padding: 25px;
    overflow-y: auto;
    flex: 1;
    min-height: 0;
}

.modal-footer {
    display: flex;
    gap: 15px;
    flex-shrink: 0;
    padding: 0 25px 25px 25px;
    justify-content: flex-end;
    margin-top: 25px;
}

/* Delete confirmation modal styles */
.delete-confirmation {
    text-align: center;
    padding: 20px 0;
}

.warning-icon {
    font-size: 48px;
    margin-bottom: 15px;
    color: #e53e3e;
}

.delete-confirmation p {
    margin-bottom: 10px;
    font-size: 1.1rem;
}

.warning-text {
    color: #e53e3e;
    font-weight: 600;
    font-size: 0.95rem !important;
}

#deleteModal .modal-header {
    background: linear-gradient(135deg, #e53e3e 0%, #c53030 100%);
}

/* Form styles */
.student-form {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.form-group label {
    font-weight: 600;
    color: #333;
    font-size: 14px;
}

.form-group input,
.form-group textarea {
    padding: 12px 15px;
    border: 2px solid #ddd;
    border-radius: 8px;
    font-size: 16px;
    transition: border-color 0.3s ease;
    font-family: inherit;
}

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

.form-group textarea {
    resize: vertical;
    min-height: 80px;
}

/* Animations */
@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes slideIn {
    from { 
        transform: translateY(-50px);
        opacity: 0;
    }
    to { 
        transform: translateY(0);
        opacity: 1;
    }
}

.fade-in {
    animation: fadeIn 0.5s ease;
}

/* Notification styles */
.notification {
    position: fixed;
    top: 20px;
    right: 20px;
    padding: 15px 20px;
    border-radius: 8px;
    color: white;
    font-weight: 600;
    z-index: 1000;
    transform: translateX(400px);
    transition: transform 0.3s ease;
}

.notification.success {
    background: #38a169;
}

.notification.error {
    background: #e53e3e;
}

/* Responsive design */
@media (max-width: 768px) {
    .container {
        padding: 15px;
    }
    
    header h1 {
        font-size: 2rem;
    }
    
    .search-controls {
        flex-direction: column;
        align-items: stretch;
    }
    
    #searchInput {
        min-width: auto;
    }
    
    .modal-content {
        margin: 0 auto;
        width: 95%;
        max-height: calc(100vh - 20px);
    }
    
    .modal {
        padding: 10px 0;
    }
    
    .students-table {
        font-size: 12px;
    }
    
    .students-table th,
    .students-table td {
        padding: 10px 8px;
    }
    
    .table-actions {
        flex-direction: column;
        gap: 5px;
    }
    
    .btn-edit,
    .btn-delete {
        padding: 6px 12px;
        font-size: 12px;
    }
}

@media (max-width: 480px) {
    .modal-header,
    .modal-body {
        padding: 20px;
    }
    
    .modal-footer {
        flex-direction: column;
        padding: 0 20px 20px 20px;
    }
    
    header {
        padding: 20px;
    }
    
    header h1 {
        font-size: 1.8rem;
    }
}