body {
    font-family: Arial;
    margin: 0;
    background:#fafafa;
}
header {
    background:#222;
    color:#fff;
    padding:15px;
    display:flex;
    justify-content:space-between;
}
header a { color:#fff; margin-left:15px; }

.hero {
    padding:50px;
    text-align:center;
    background:#eee;
}

.product-grid {
    display:grid;
    grid-template-columns:repeat(auto-fit,minmax(200px,1fr));
    gap:20px;
    padding:20px;
}
.item {
    background:white;
    padding:20px;
    border-radius:10px;
}