header i {
    cursor: pointer;
}

main ul button:hover {
    transform: scale(1.35);
}

main ul button:focus,
main ul button:focus-visible {
    outline: none;
    box-shadow: 0 0 0 4px rgba(0, 123, 255, 0.18);
    transform: scale(1.61);
}

main ul button:active {
    transform: scale(0.95);
    filter: brightness(0.9);
}