:root {
    --primary-color: #4CAF50;
    --secondary-color: #2196F3;
    --accent-color: #FF9800;
    --danger-color: #f44336;
    --background-color: #f5f7fa;
    --card-background: #ffffff;
    --text-primary: #333333;
    --text-secondary: #666666;
    --border-color: #e0e0e0;
    --shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
    --border-radius: 8px;
    --transition: all 0.3s ease;
}

* {
    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 {
    max-width: 1400px;
    margin: 0 auto;
    padding: 20px;
}

/* Header Styles */
.header {
    background: var(--card-background);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    margin-bottom: 20px;
    padding: 20px;
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 20px;
}

.header h1 {
    color: var(--primary-color);
    font-size: 2rem;
    font-weight: 600;
}

.header h1 i {
    margin-right: 10px;
}

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

.view-toggle {
    display: flex;
    background: var(--background-color);
    border-radius: var(--border-radius);
    padding: 4px;
}

/* Button Styles */
.btn {
    padding: 10px 20px;
    border: none;
    border-radius: var(--border-radius);
    cursor: pointer;
    font-weight: 500;
    transition: var(--transition);
    display: inline-flex;
    align-items: center;
    gap: 8px;
    text-decoration: none;
    font-size: 14px;
}

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

.btn-primary:hover {
    background: #45a049;
    transform: translateY(-2px);
}

.btn-secondary {
    background: var(--background-color);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background: #e9ecef;
}

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

.btn-outline {
    background: transparent;
    color: var(--secondary-color);
    border: 2px solid var(--secondary-color);
}

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

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

.btn-danger:hover {
    background: #d32f2f;
}

/* Navigation Styles */
.navigation {
    display: flex;
    justify-content: space-between;
    align-items: center;
    background: var(--card-background);
    padding: 15px 20px;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    margin-bottom: 20px;
}

.date-navigation {
    display: flex;
    align-items: center;
    gap: 20px;
}

.nav-btn {
    background: none;
    border: none;
    font-size: 18px;
    cursor: pointer;
    padding: 10px;
    border-radius: 50%;
    transition: var(--transition);
    color: var(--text-secondary);
}

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

.current-date {
    font-size: 1.2rem;
    font-weight: 600;
    color: var(--text-primary);
    min-width: 200px;
    text-align: center;
}

/* Main Content Layout */
.main-content {
    display: grid;
    grid-template-columns: 1fr 300px;
    gap: 20px;
    margin-bottom: 20px;
}

.view-container {
    background: var(--card-background);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    padding: 20px;
    min-height: 600px;
}

.hidden {
    display: none;
}

/* Daily View Styles */
.daily-schedule {
    display: grid;
    grid-template-columns: 80px 1fr;
    gap: 20px;
    height: 100%;
}

.time-slots {
    display: flex;
    flex-direction: column;
    gap: 1px;
}

.time-slot {
    height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 12px;
    color: var(--text-secondary);
    border-bottom: 1px solid var(--border-color);
    font-weight: 500;
}

.schedule-grid {
    position: relative;
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
    background: linear-gradient(transparent 59px, var(--border-color) 59px);
    background-size: 100% 60px;
}

.class-block {
    position: absolute;
    left: 10px;
    right: 10px;
    background: var(--primary-color);
    color: white;
    border-radius: 6px;
    padding: 8px 12px;
    cursor: pointer;
    transition: var(--transition);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.15);
}

.class-block:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.2);
}

.class-name {
    font-weight: 600;
    font-size: 14px;
    margin-bottom: 2px;
}

.class-info {
    font-size: 12px;
    opacity: 0.9;
}

/* Weekly View Styles */
.weekly-schedule {
    height: 100%;
}

.week-header {
    display: grid;
    grid-template-columns: 80px repeat(7, 1fr);
    gap: 1px;
    margin-bottom: 20px;
}

.week-day {
    background: var(--background-color);
    padding: 15px 10px;
    text-align: center;
    font-weight: 600;
    border-radius: var(--border-radius);
    color: var(--text-primary);
}

.week-day.today {
    background: var(--primary-color);
    color: white;
}

.week-grid {
    display: grid;
    grid-template-columns: 80px repeat(7, 1fr);
    gap: 1px;
    height: calc(100% - 80px);
}

.week-time-slot {
    height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 12px;
    color: var(--text-secondary);
    background: var(--background-color);
    border-radius: var(--border-radius);
    margin-bottom: 1px;
}

.week-day-column {
    position: relative;
    background: repeating-linear-gradient(
        transparent,
        transparent 59px,
        var(--border-color) 59px,
        var(--border-color) 60px
    );
    border: 1px solid var(--border-color);
    border-radius: var(--border-radius);
}

.week-class-block {
    position: absolute;
    left: 4px;
    right: 4px;
    background: var(--primary-color);
    color: white;
    border-radius: 4px;
    padding: 4px 8px;
    cursor: pointer;
    transition: var(--transition);
    font-size: 12px;
    overflow: hidden;
}

.week-class-block:hover {
    transform: translateX(2px);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

/* Statistics Panel */
.stats-panel {
    background: var(--card-background);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    padding: 20px;
    height: fit-content;
}

.stats-panel h3 {
    color: var(--text-primary);
    margin-bottom: 20px;
    font-size: 1.1rem;
}

.stats-grid {
    display: grid;
    gap: 15px;
}

.stat-item {
    text-align: center;
    padding: 15px;
    background: var(--background-color);
    border-radius: var(--border-radius);
    transition: var(--transition);
}

.stat-item:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.stat-number {
    display: block;
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 5px;
}

.stat-label {
    font-size: 0.9rem;
    color: var(--text-secondary);
    font-weight: 500;
}

/* 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);
    backdrop-filter: blur(5px);
}

.modal-content {
    background: var(--card-background);
    margin: 5% auto;
    padding: 0;
    border-radius: var(--border-radius);
    width: 90%;
    max-width: 500px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
    animation: modalSlideIn 0.3s ease;
}

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

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px;
    border-bottom: 1px solid var(--border-color);
}

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

.close-btn {
    background: none;
    border: none;
    font-size: 24px;
    cursor: pointer;
    color: var(--text-secondary);
    padding: 0;
    width: 30px;
    height: 30px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 50%;
    transition: var(--transition);
}

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

/* Form Styles */
#classForm {
    padding: 20px;
}

.form-group {
    margin-bottom: 20px;
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 15px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: var(--text-primary);
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 12px;
    border: 2px solid var(--border-color);
    border-radius: var(--border-radius);
    font-size: 14px;
    transition: var(--transition);
    font-family: inherit;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(76, 175, 80, 0.1);
}

.form-actions {
    display: flex;
    gap: 10px;
    justify-content: flex-end;
    padding-top: 20px;
    border-top: 1px solid var(--border-color);
}

/* Class Details */
.class-details {
    padding: 20px;
}

.detail-item {
    margin-bottom: 15px;
    padding: 10px;
    background: var(--background-color);
    border-radius: var(--border-radius);
}

.detail-label {
    font-weight: 600;
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 5px;
}

.detail-value {
    color: var(--text-primary);
    font-size: 1rem;
}

/* Notifications */
.notification-container {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 1100;
    max-width: 400px;
}

.notification {
    background: var(--card-background);
    border-radius: var(--border-radius);
    box-shadow: var(--shadow);
    padding: 15px 20px;
    margin-bottom: 10px;
    border-left: 4px solid var(--primary-color);
    animation: slideInRight 0.3s ease;
}

.notification.error {
    border-left-color: var(--danger-color);
}

.notification.success {
    border-left-color: var(--primary-color);
}

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

/* Responsive Design */
@media (max-width: 768px) {
    .container {
        padding: 10px;
    }
    
    .header-content {
        flex-direction: column;
        align-items: stretch;
    }
    
    .header-controls {
        justify-content: space-between;
    }
    
    .main-content {
        grid-template-columns: 1fr;
    }
    
    .daily-schedule {
        grid-template-columns: 60px 1fr;
    }
    
    .week-header,
    .week-grid {
        grid-template-columns: 60px repeat(7, 1fr);
    }
    
    .form-row {
        grid-template-columns: 1fr;
    }
    
    .modal-content {
        width: 95%;
        margin: 10% auto;
    }
    
    .current-date {
        min-width: auto;
    }
}

@media (max-width: 480px) {
    .header h1 {
        font-size: 1.5rem;
    }
    
    .btn {
        padding: 8px 12px;
        font-size: 12px;
    }
    
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    
    .week-header,
    .week-grid {
        grid-template-columns: 40px repeat(7, 1fr);
    }
    
    .week-day {
        padding: 10px 5px;
        font-size: 12px;
    }
}