styles.css

body {
    font-family: 'Roboto', sans-serif;
    background-color: #f2f2f2;
    margin: 0;
    padding: 0;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
}

.calculator {
    background-color: #fff;
    border-radius: 10px;
    box-shadow: 0 0 20px rgba(0, 0, 0, 0.1);
    overflow: hidden;
}

.calculator input[type="text"] {
    width: calc(100% - 20px);
    padding: 20px 10px;
    border: none;
    border-radius: 10px 10px 0 0;
    font-size: 36px;
    text-align: right;
    outline: none;
}

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

button {
    padding: 20px;
    border: none;
    background-color: #eaeaea;
    color: #333;
    font-size: 24px;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

button:hover {
    background-color: #d4d4d4;
}

button.operator {
    background-color: #ff9500;
    color: #fff;
}

button.operator:hover {
    background-color: #ff7800;
}

button.clear {
    background-color: #ff3b30;
    color: #fff;
}

button.clear:hover {
    background-color: #ff6552;
}