/* Index Page Styles */
.index-page {
    max-width: 1000px;
}
.concepts-intro {
    text-align: center;
    margin-bottom: 2rem;
}
.concepts-intro p {
    color: var(--text-muted);
    font-size: 1.1rem;
    line-height: 1.6;
}
.concepts-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 1.5rem;
}
.concept-card {
    background: var(--card-bg);
    border-radius: 16px;
    padding: 2rem;
    backdrop-filter: blur(10px);
    border: 1px solid var(--border-color);
    box-shadow: var(--card-shadow);
    transition: transform 0.2s ease, box-shadow 0.2s ease, background 0.3s ease, border-color 0.3s ease;
    text-decoration: none;
    display: flex;
    flex-direction: column;
    gap: 1rem;
}
.concept-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--card-shadow-hover);
    border-color: var(--accent-color);
}
.concept-card h2 {
    color: var(--text-heading);
    font-size: 1.5rem;
    margin: 0;
}
.concept-description {
    color: var(--text-muted);
    line-height: 1.6;
    flex-grow: 1;
    margin: 0;
}
.concept-meta {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding-top: 1rem;
    border-top: 1px solid var(--border-subtle);
}
.example-count {
    color: var(--accent-color);
    font-size: 0.9rem;
    font-weight: 600;
}
/* Responsive adjustments */
@media (max-width: 768px) {
    .concepts-grid {
        grid-template-columns: 1fr;
    }

    .concept-card {
        padding: 1.5rem;
    }
}