.viewscreen {
    display: flex;
    flex-direction: column;
    background-color: black;
/*     background: linear-gradient(#25364f,#4d71a5, #9bc4ff); */
/*     background: linear-gradient(#4f2a25,#a5754d, #ffe89b); */


    align-items: center;
    justify-content: center;
    height: 97vh;
    width: 97vh;
    margin: 0 auto;
    border-width: 3px;
    border-color: black;
    border-style: solid;
}
.calc_buttons {
    display: grid;
    grid-template-columns: 100px 100px 100px 100px 100px;
    justify-content: center;
    align-items: center;
    /* border-width: 3px;
    border-color: black;
    border-style: solid; */
}

.calc_buttons .number {
    height:100px;
    /* width:100px; */
    margin:5px;
    background-color:whitesmoke;

    border-width: 1px;
    border-color: black;
    border-style: solid;
}
.calc_buttons .operation {
    height: 100px;
    /* width: 100px; */
    margin: 5px;
    background-color:whitesmoke;

    border-width: 1px;
    border-color: black;
    border-style: solid;

}

.operation:hover {
    cursor: pointer;
    background-color: aqua;
}

.number:hover {
    cursor: pointer;
    background-color: rgb(255, 196, 0);
}


#screen {
    width: 500px;
    height: 100px;
    margin: 20px;
    text-align: right;
    justify-content: right;
    height: 25%;
    font-size: 40px;
    font-family: Arial, Helvetica, sans-serif;
    background-color: rgba(255, 255, 255, 0.986);
    border-width: 2px;
    border-color: black;
    border-style: solid;
}