/* 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: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
}

/* Header styles */
header {
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    padding: 2rem;
    text-align: center;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);
    margin-bottom: 2rem;
}

header h1 {
    color: #2c3e50;
    font-size: 2.5rem;
    margin-bottom: 1rem;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.1);
}

header p {
    color: #555;
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
}

/* Main content */
main {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1rem;
}

/* Instructions section */
.instructions {
    background: rgba(255, 255, 255, 0.9);
    padding: 1.5rem;
    border-radius: 15px;
    margin-bottom: 2rem;
    text-align: center;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
}

.instructions h2 {
    color: #2c3e50;
    font-size: 1.5rem;
}

/* Courses grid */
.courses-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.course-btn {
    background: linear-gradient(145deg, #f0f0f0, #cacaca);
    border: none;
    padding: 1rem;
    border-radius: 12px;
    cursor: pointer;
    font-size: 1rem;
    font-weight: 600;
    color: #333;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    position: relative;
    overflow: hidden;
}

.course-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.15);
}

.course-btn.completed {
    background: linear-gradient(145deg, #4CAF50, #45a049);
    color: white;
    box-shadow: 0 4px 15px rgba(76, 175, 80, 0.3);
}

.course-btn.completed::after {
    content: '✓';
    position: absolute;
    top: 5px;
    right: 10px;
    font-size: 1.2rem;
    font-weight: bold;
}

.course-btn.allowed {
    background: linear-gradient(145deg, #2196F3, #1976D2);
    color: white;
    box-shadow: 0 4px 15px rgba(33, 150, 243, 0.3);
}

.course-btn.blocked {
    background: linear-gradient(145deg, #f44336, #d32f2f);
    color: white;
    opacity: 0.7;
    cursor: not-allowed;
}

/* Summary section */
.summary {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.summary-item {
    background: rgba(255, 255, 255, 0.9);
    padding: 1.5rem;
    border-radius: 15px;
    text-align: center;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
    transition: transform 0.3s ease;
}

.summary-item:hover {
    transform: translateY(-5px);
}

.summary-item h3 {
    color: #2c3e50;
    margin-bottom: 0.5rem;
    font-size: 1.1rem;
}

.summary-item p {
    font-size: 2rem;
    font-weight: bold;
    color: #3498db;
}

/* Allowed courses section */
.allowed-courses {
    background: rgba(255, 255, 255, 0.9);
    padding: 2rem;
    border-radius: 15px;
    margin-bottom: 2rem;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
}

.allowed-courses h2 {
    color: #2c3e50;
    margin-bottom: 1rem;
    text-align: center;
}

#allowed-courses-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
}

.allowed-course {
    background: linear-gradient(145deg, #e8f5e8, #c8e6c9);
    padding: 1rem;
    border-radius: 10px;
    text-align: center;
    font-weight: 600;
    color: #2e7d32;
    box-shadow: 0 4px 15px rgba(46, 125, 50, 0.2);
}

/* Notes section */
.notes {
    background: rgba(255, 255, 255, 0.9);
    padding: 2rem;
    border-radius: 15px;
    margin-bottom: 2rem;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
}

.notes h2 {
    color: #e74c3c;
    margin-bottom: 1rem;
}

.notes ul {
    list-style-type: none;
    padding-right: 1rem;
}

.notes li {
    background: #fff3cd;
    margin: 0.5rem 0;
    padding: 0.5rem;
    border-radius: 5px;
    border-right: 4px solid #ffc107;
}

/* Footer */
footer {
    background: rgba(44, 62, 80, 0.9);
    color: white;
    text-align: center;
    padding: 1.5rem;
    margin-top: 2rem;
}

/* Responsive design */
@media (max-width: 768px) {
    header h1 {
        font-size: 2rem;
    }
    
    header p {
        font-size: 1rem;
    }
    
    .courses-grid {
        grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
        gap: 0.8rem;
    }
    
    .course-btn {
        padding: 0.8rem;
        font-size: 0.9rem;
    }
    
    .summary {
        grid-template-columns: 1fr;
    }
    
    #allowed-courses-list {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    header {
        padding: 1rem;
    }
    
    header h1 {
        font-size: 1.8rem;
    }
    
    .courses-grid {
        grid-template-columns: 1fr;
    }
    
    main {
        padding: 0 0.5rem;
    }
}

/* Animation for course buttons */
@keyframes pulse {
    0% {
        transform: scale(1);
    }
    50% {
        transform: scale(1.05);
    }
    100% {
        transform: scale(1);
    }
}

.course-btn.completed {
    animation: pulse 0.6s ease-in-out;
}

/* Loading animation */
.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid #f3f3f3;
    border-top: 3px solid #3498db;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

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