:root {
    --black: #000000;
    --orange: #e6630c;
}

body {
    box-sizing: border-box;
    margin: 0;
    text-align: center;
}

main {
    align-items: center;
    display: flex;
    height: 100vh;
    justify-content: center;
}

.calculator {
    background-color: var(--black);
    border: 10px solid black;
    border-radius: 30px;
    padding: 10px;
}

.display {
    align-items: flex-end;
    background-color: var(--black);
    border: 2px solid var(--orange);
    border-radius: 5px;
    color: #eeee;
    display: flex;
    flex-direction: column;
    font-size: 50px;
    grid-column: 1 / -1;
    height: 80px;
    justify-content: space-around;
    max-width: 378px;
    overflow: hidden;
    padding: 10px;
}

.previous-number {
    font-size: medium;
}

.calculator-keys {
    background-color: #0000;
    display: grid;
    gap: 2px;
    grid-template-columns: repeat(4, 100px);
    grid-template-rows: repeat(5, 80px);
    margin-top: 10px;
}

.clear {
    color: var(--orange);
    background-color: var(--black)
}

.delete {
    color: #e6630c;
    background-color: var(--black)
}

.operator {
    color: #e6630c;
    background-color: var(--black)
}

.equal {
    background-color: var(--orange);
    color: #eeee;
    grid-column: span 2;
}

button {
    color: #eeee;
    border-radius: 7px;
    font-size: 30px;
    background-color: var(--black);
}

button:active {
    background-color: rgb(27, 27, 34);
}