body{
    background-color: black;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
    font-family: 'roboto', sans-serif;
}

.calculator {
    background-color:gray;
    padding: 20px;
    border-radius: 10px;
    box-shadow: inset 0 0 10px rgba(0, 0, 0, 0.5);
    width: 300px;
}

.display {
    background-color: #eee;
    padding: 15px;
    border-radius: 10px;
    margin-bottom: 15px;
    text-align: right;
    font-size: 24px;
    height: 30px;
    overflow: hidden;
}

.buttons {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
}

button {
    padding: 15px;
    font-size: 18px;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    background-color: lightgray;
    transition: background-color 0.2s ease;
}

button:hover {
    background-color: darkgray;
}

button:active {
    background-color: rgb(255, 4, 4);
}

.operator {
    background-color: #3e61fc;
}

.operator:hover {
    background-color: darkblue;
}

.operator:active {
    background-color: rgb(0, 0, 255);
}

.equals {
    background-color: green;
    grid-column: span 2;
}

.clear {
    background-color: rgb(234, 49, 49);
}
.clear:hover {
    background-color: darkred;
}