#tahvel{
    background-color: greenyellow;
    width: 30%;
    height: 20%;
}
h1{
    background-color: lightskyblue;
    color: darkviolet;
    line-height: 2;
    text-align: center;
    font-family: serif, Arial;
}
input[type=button]{
    background-color: crimson;
    color: lightgoldenrodyellow;
    padding: 15px 25px;
    border: 0;
}
input[type=button]:hover{
    background-color: chocolate;
}