styles.css

body {
    min-height: 620px;
    display: flex;
    justify-content: center;
    align-content: center;
    align-items: center;
    height: 100px;
    background-color: rgb(126, 102, 102);
    overflow: hidden;
}

.container {
    background-color: rgb(133, 131, 13);
    border: 10px solid rgb(0, 0, 0);
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    grid-template-rows: minmax(100px, auto) repeat(5, 80px);
    gap:2px;

}

#display {
    background-color: azure;
    grid-column: 1 / -1;
    display: flex;
    flex-direction: column;
    justify-content: space-around;
    align-items: flex-end;
    font-size: 50px;
    font-weight: 400px;
    padding: 5px;
    margin: 5px;
}

button {
    margin: 1px;
    border-radius: 5%;
    border: none;
    font-weight: initial;
    font-size: 50px;
    font-family: monospace;
}

#zero {
    grid-column: span 2;
}

.operand {
    background-color: rgb(234, 238, 12);
}

.operand:active {
    background-color: rgb(251, 255, 15);
}


.operator {
    background-color: rgb(49, 219, 211);
}


.operator:active {
    background-color: rgb(61, 241, 232);
}

.clear, .sign, .decimal, .equals, .percent {
    background-color: rgb(250, 230, 201);
}

.clear:active, .sign:active, .decimal:active, .equals:active, .percent:active {
    background-color: rgb(255, 239, 218);
}