odin-codespace/calculator/css/style.css

.container {
    width: 500px;
    padding: 15px 0;
    background-color: #C7B198;
    border-radius: 10px;
}

.screen {
    height: 100px;
    background-color: #DFD3C3;
    margin: 10px 18px 15px;
    border: 2px solid #596E79;
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    align-items: flex-end;
    font-family: 'Orbitron', sans-serif;
    font-weight: 500;
    font-size: 4.5em;
    padding: 4px;
    color: #000;
}

.buttons {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    align-content: center;
    width: 500px;
}

.btn {
    padding: 20px;
    border: 2px solid #596E79;
    border-radius: 5px;
    cursor: pointer;
    margin: 5px;
    font-size: 25px;
    width: 110px;
    -webkit-transition: all 0.5s; /* add this line, chrome, safari, etc */
    -moz-transition: all 0.5s; /* add this line, firefox */
    -o-transition: all 0.5s; /* add this line, opera */
    transition: all 0.5s; /* add this line */
}

#clear {
    background-color: #F1C93B;
}

#action {
    background-color: #7EAA92;
}

#zero {
    width: 230px;
}

#action:hover {
    background-color: #F0ECE2;
}

#clear:hover {
    background-color: #FF6D60;
}

body {
    display: flex;
    justify-content: center;
    align-content: center;
    align-items: center;
    height: 75vh;
    min-height: 500px;
    margin-top: 80px;
    padding: 10px;
    background-color: #F0ECE2;
}