style.css

@import url('https://fonts.googleapis.com/css?family=Montserrat&display=swap');
body {
    background: #c79691;
    background: linear-gradient(#f34e64f1, #c74859f1, #f34e64f1);
    font-family: 'Montserrat', sans-serif;
}

.container {
    background: #EEEEEE;
    width: 320px;
    height: 550px;
    border-radius: .5em;
    box-shadow: 4px 4px 10px 0 #0000024d;
    margin: 0 auto;
    padding: 32px 16px;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

.container .result {
    width: 100%;
    height: 150px;
}

.container .result p {
    font-size: 45pt;
    overflow-y: auto;
    text-align: right;
}

.container .buttons {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    grid-gap: 1em;
}

.container .buttons .button,
.container .buttons .num-button {
    cursor: grab;
    text-align: center;
    width: 60px;
    height: 60px;
    display: grid;
    place-content: center;
    /* border-radius: 50%; */
    box-shadow: 6px 6px 16px 0 #463b2b80, -6px -6px 16px 0 rgba(255, 255, 255, 0.5);
}


/*  UTILITIES*/

.container .buttons .zero {
    grid-column: 1/ 3;
    width: 100%;
    border-radius: 10px;
    box-shadow: 6px 6px 16px 0 #d1cdc780, -6px -6px 16px 0 #ffffff80;
}

.action-btn {
    color: grey;
    font-weight: bold;
}

.calc-action-btn {
    color: orange;
    font-weight: bold;
}