body{
   display: flex;
   justify-content: space-around;
}

.container {
    width: 500px;
	max-width: 360px;
	box-shadow: 0px 0px 22px 8px gray;
}
#result {
    text-align: right;
    height: 50px;
    line-height: 30px;
    padding: 4% 2%;
    font-size: 25px;
    font-family: 'courier';
}
.bttns {
    display: grid;
    border: 1px;
    grid-template-columns: 1fr 1fr 1fr 1fr;
}
.bttns div {
    border-top: 1px solid #999;
}
.btn {
    border: .5px solid gray;
    line-height: 100px;
    text-align: center;
    font-size: 20px;
    cursor: pointer;
}
#equal {
    background-color: dodgerblue;
    color: white;
    font-size: 30px;
}
#clear{
    background-color: tomato;
    color: white;
}
.btn:hover {
    background-color: lightgray;
}
#equal:hover{
    background-color: blue;
}
#clear:hover{
    background-color: red;
}