button {
    width: 100px;
    height: 100px;
    border: none;
    background-color: hsl(230, 15%, 25%);
    color: white;
    font-size: 4rem;
    font-weight: bold;
    cursor: pointer;
    font-family: "JetBrains Mono", monospace;
    border: 2px solid white;
    border-radius: 25px;
}


#keys {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
    padding: 25px;
}

#delete {
    grid-column: span 2;
    width: 210px;
}

#equal {
    grid-row: span 2;
    height: 210px
}


#calculator {
    font-family: "JetBrains Mono", monospace;
    background-color: hsl(230, 30%, 20%);
    max-width: 500px;
    overflow: hidden;
    border: 10px solid hsl(180, 100%, 40%);
    border-radius: 25px;
}

#display {
    font-family: "JetBrains Mono", monospace;
    width: 100%;
    padding: 20px;
    font-size: 6rem;
    text-align: left;
    border: none;
    background-color: hsl(230, 20%, 20%);
    color: white;
    border: 2px solid hsl(180, 100%, 40%);
}

body {
    margin: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    background-color: hsl(230, 30%, 15%);
}

button:hover {
    background-color: hsl(230, 15%, 35%);
}

button:active {
    background-color: hsl(230, 15%, 45%);
}

.operator-btn {
    background-color: hsl(180, 100%, 40%);
}

.operator-btn:hover {
    background-color: hsl(180, 100%, 45%);
}

.operator-btn:active {
    background-color: hsl(180, 100%, 65%);
}