* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    background-color: whitesmoke;
    padding: 30px 0;
}

.calculator {
    width: 400px;
    margin: 0 auto;
    background-color: #eaedef;
    padding: 20px;
    border-radius: 5px;
    box-shadow: 0 0 3px black;
}

.display {
    display: flex;
    justify-content: flex-end;
    width: 100%;
    height: 75px;
    margin-bottom: 20px;
    padding: 15px;
    background-color: #dde0e2;
    font-family: 'Gill Sans', 'Gill Sans MT', Calibri, 'Trebuchet MS', sans-serif;
    font-size: 2.5em;
    color: #000;
    overflow: hidden;
    border-radius: 5px;
}

.calculator-buttons {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr 1fr;
    grid-gap: 20px;
}

.calculator button {
    font-family:'Gill Sans', 'Gill Sans MT', Calibri, 'Trebuchet MS', sans-serif;
    background-color: #eaedef;
    color: #000;
    padding: 20px;
    border-radius: 50%;
    font-size: 1.4rem;
    outline: none;
    border: 0px solid black;
    /* cursor: pointer; */
}

button:hover {
    background-color: #dde0e2;
    transition: 0.2s;
}

button:nth-child(4) {
    background-color: #cfd0fe;
}

button:nth-child(8) {
    background-color: #cfd0fe;
}

button:nth-child(12) {
    background-color: #cfd0fe;

}
button:nth-child(16) {
    background-color: #cfd0fe;
}

button:nth-child(20) {
    background-color: #cfd0fe;
}

button:nth-child(17) {
    background-color: #eaedef;
}