.kartu-materi {
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}
.kartu-materi:hover {
    transform: translateY(-5px);
    box-shadow: 0 0.5rem 1rem rgba(0,0,0,.15);
}
.rumus {
    font-family: "Times New Roman", serif;
    font-style: italic;
}