style.css

body {
    background-color: rgb(0, 26, 52);
    display: flex;
    justify-content: center;
    font-family:Impact, Haettenschweiler, 'Arial Narrow Bold', sans-serif
}

.outline {
    margin: 60px;
    background-color: black;
    height: 500px;
    width: 400px;
    display: flex;
    flex-direction: column;
    border-radius: 15px;
    box-shadow: 0 0 0.5rem #050505;
}

@media screen and (max-width: 450px) {
    .outline {
        transform: scale(0.7);
    }
}

.display {
    background-color: grey;
    width: 345px;
    height: 100px;
    margin: 20px;
    border-radius: 20px;
    align-self: center;
}

.display .calc {
    /* background-color: rgba(128, 0, 128, 0.235); */
    height: 15px;
    width: 315px;
    text-align: right;
    padding: 10px;
    padding-right: 20px;
}

.display .result {
    /* background-color: rgba(127, 255, 212, 0.266); */
    height: 45px;
    width: 315px;
    padding: 10px;
    padding-right: 20px;
    text-align: right;
    font-size: 35px;
}

.buttons {
    margin: 20px;
    margin-top: 0px;
    height: 420px;
    display: flex;
    flex-wrap: wrap;
    justify-content: space-around;
    align-items: center;
}

.buttons button {
    text-align: center;
    -webkit-appearance: none;
    background-color: white;
    border-radius: 20px;
    width: 75px;
    height: 75px;
    font-size: 35px;
    font-weight:700;
    border-color: orange;
    border-width: 3px;
}

.buttons button:active {
    /* transform: translate(-2px, -2px); */
    transform: scale(0.97);
}

#equals {
    background-color: rgb(255, 132, 0);
}