style.css

body {
    background-color: rgb(255, 255, 255);
    display: flex;
    justify-content: center;
    min-width: 70%;
}

#mdiv {
    padding: 10px;
    margin-top: 3rem;
    width:60%;
    height:70%;
    background-color: rgba(84, 71, 71, 0.7);
    min-width: 60%;
 
}
#head{
    background-color: rgb(0, 0, 0);
    width: 100%;
    height:6rem; 
    border: 2px rgb(255, 255, 255) solid;
    margin-bottom: 10px;
}
#head p{
    margin-top: 0px;
    font-size: 70px;
    text-align: center;
    color:aliceblue;
}
#Darea{
    width: 100%;
    height:5rem; 
    background-color: aliceblue;
    margin-bottom: 5px;
    display: flex;
    flex-direction:row-reverse;
}
#Darea{
    font-size: 3rem;
    font-family: 'Gill Sans', 'Gill Sans MT', Calibri, 'Trebuchet MS', sans-serif;
    font-weight: 200;
}
#buttonsarea{
    width: 100%;
    height: 70%;
    background-color: rgb(255, 255, 255);
    padding:0.5%;
    display: flex;
    flex-direction: row;
    flex-wrap:wrap;
}
.nums{
    width: 24.5%;
    background-color: rgb(166, 192, 212);
    height: 25%;
    text-align: center;
    margin:0.15% 0.25%;
    padding-top: 0.25% ;
    font-size: 2.8rem;
    font-family: Cambria, Cochin, Georgia, Times, 'Times New Roman', serif;
}
.num{
    background-color: rgb(255, 151, 87);
}
#zero{
    width: 49.3%;
}
.nums:hover{
    background-color: rgb(95, 163, 205);
}
.num:hover{
    background-color:  rgb(186, 94, 37);;
}