button {
    border-radius: 50%;
    display: flex;
    justify-content: center;
    align-items: center;
    width: 50px;
    height: 50px;
    background-color: #999999;
    color: #333;
    font-size: 22px;
    transition: background-color 0.3s, transform 0.3s;
    cursor: pointer;
}

button:hover {
    transform: scale(1.1);
}

button:focus {
    outline: none;
}