* {
    padding: 0;
    margin: 0;
    box-sizing: border-box;
    font-family: 'Roboto', sans-serif;
}

body {
    width: 100vw;
    height: 100vh;
    background-color: beige;
    display: flex;
    justify-content: center;
    align-items: center;
}

/* calculator */

.calculator {
    display: flex;
    flex-direction: column;
    align-items: center;
    background-color: rgb(248, 215, 174);
    border: 3px solid orange;
    border-radius: 10px;
    width: 400px;
    padding: 28px;
    gap: 16px;
}

/* display */

.display-area {
    padding: 8px 8px 0 8px;
    width: 100%;
}

.display {
    border: 3px solid orange;
    border-radius: 10px;
    background-color: azure;
    text-align: right;
    width: 100%;
    padding: 24px 8px;
    font-size: 20px;
    height: calc(24px * 2 + 3px * 2 + 20px);
    overflow: hidden;
}

/* buttons */

.button-area {
    display: flex;
    flex-wrap: wrap;
    padding-top: 16px;
}

button {
    margin: 8px;
    width: calc((100% / 4) - 16px);
    aspect-ratio: 1/1;
    font-size: 24px;
    border-radius: 10px;
    border: none;
    border-bottom: 3px solid orange;
    border-right: 3px solid orange;
}

#github-button {
    background-color: orange;
    border-bottom-color: rgb(185, 148, 45);
    border-right-color: rgb(185, 148, 45);
}

#github-logo {
    width: 32px;
    height: auto;
}

#github-button > a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    height: 100%;
}

button:hover {
    filter: brightness(0.90);
}

.utility, .operator {
    color: orange;
}

#equal {
    background-color: orange;
    color: azure;
    border-bottom-color: rgb(185, 148, 45);
    border-right-color: rgb(185, 148, 45);
}

.button-down {
    border: none;
}