:root {
    --primary: #4a6fa5;
    --background: #f8f9fa;
    --card-bg: #ffffff;
    --text: #333333;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    background-color: var(--background);
    color: var(--text);
    line-height: 1.6;
}

.header {
    background-color: var(--primary);
    color: white;
    padding: 1.5rem 1rem;
    text-align: center;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.container {
    padding: 2rem 1rem;
    max-width: 1200px;
    margin: 0 auto;
}

h2 {
    margin-bottom: 1.5rem;
    font-size: 1.5rem;
}

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

/* Mobile First: For larger screens, use more columns */
@media (min-width: 600px) {
    .subject-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (min-width: 900px) {
    .subject-grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

.card {
    background-color: var(--card-bg);
    border-radius: 12px;
    padding: 1.5rem;
    display: flex;
    align-items: center;
    text-decoration: none;
    color: inherit;
    box-shadow: 0 4px 6px rgba(0,0,0,0.05);
    transition: transform 0.2s, box-shadow 0.2s;
}

.card:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 12px rgba(0,0,0,0.1);
}

.card-icon {
    font-size: 2.5rem;
    margin-right: 1.5rem;
}

.card-content h3 {
    margin-bottom: 0.25rem;
    color: var(--primary);
}

.card-content p {
    font-size: 0.9rem;
    color: #666;
}