body{
    margin:0;
    background:#111827;
    color:white;
    font-family:Arial, Helvetica, sans-serif;
}

header{
    background:#1f2937;
    text-align:center;
    padding:30px;
    border-bottom:2px solid #333;
}

header h1{
    margin:0;
    font-size:2.3rem;
}

header p{
    color:#cbd5e1;
}

main{
    max-width:1200px;
    margin:auto;
    padding:25px;
}

h2{
    margin-top:40px;
}

.cards{
    display:grid;
    grid-template-columns:repeat(auto-fill,minmax(280px,1fr));
    gap:20px;
}

.card{
    background:#1f2937;
    border-radius:14px;
    padding:18px;
    box-shadow:0 8px 20px rgba(0,0,0,.35);
    transition:.2s;
}

.card:hover{
    transform:translateY(-4px);
}

.placeholder{
    text-align:center;
    color:#cbd5e1;
}