*{
    padding: 0;
    margin: 0;
    box-sizing: border-box;
}
html{
    font-family: Arial, Helvetica, sans-serif;
}

.container{
    width: 90%;
    max-width: 300px;
    background-color: rgb(70, 177, 189);
    border-radius: 8px;
    overflow: hidden;
    margin: auto;
    margin-top: 50px;
}
.display-screen{
    background-color: rgb(168, 229, 240);
    height: 100px;
    width: 100%;
    text-align: right;
    padding: 20px;
    font-size: 30px;
    position: relative;
}
.screen-1{
    opacity: .4;
    font-size: 20px;
    height: 20px;
    overflow: hidden;
}
.temporary-result{
    position: absolute;
    bottom: 0;
    left: 10;
    font-size: 20px;
    opacity: .4;
}
.total-btns{
    color: whitesmoke;
    display: grid;
    grid-template: repeat(4, 1fr)/repeat(4, 1fr);

}
.btn{
    border: .5px solid rgb(92, 92, 92,0.137);
    display: inline-block;
    height: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    cursor: pointer;
}
.btn:hover{
    background-color: rgb(26, 98, 114);
}
.btn-0{
    grid-column: 1/3;
}