:root {
    --primary-color: #2a76c6;
    --accent-color: #ff7f50;
    --text-color: #333;
    --bg-color: #f4f4f4;
    --surface-color: #ffffff;
    --shadow-color: rgba(0, 0, 0, 0.1);
}

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

body {
    font-family: 'Open Sans', sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
}

h1, h2, h3 {
    font-family: 'Montserrat', sans-serif;
    font-weight: 700;
    color: var(--primary-color);
}

a {
    color: var(--accent-color);
    text-decoration: none;
}

main {
    padding: 2rem 1rem;
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 1.5rem;
}

/* === Site Header === */
site-header {
    display: block;
    background-color: var(--surface-color);
    padding: 1rem 2rem;
    box-shadow: 0 2px 5px var(--shadow-color);
    position: sticky;
    top: 0;
    z-index: 10;
}

/* === Site Footer === */
site-footer {
    display: block;
    background-color: #333;
    color: #fff;
    text-align: center;
    padding: 2rem 1rem;
    margin-top: 2rem;
}

/* === Article Card === */
article-card {
    display: block;
    background-color: var(--surface-color);
    border-radius: 8px;
    box-shadow: 0 4px 8px var(--shadow-color);
    overflow: hidden;
    transition: transform 0.2s ease-in-out, box-shadow 0.2s ease-in-out;
}

article-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.15);
}

@media (max-width: 768px) {
    main {
        padding: 1rem;
    }

    site-header {
        padding: 1rem;
    }
}