body {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    margin: 0;
    background-color: #f0f0f0;
    font-family: 'Arial', sans-serif;
}

.calculator {
    background: rgba(255, 255, 255, 0.95);
    border-radius: 20px;
    padding: 20px;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.1);
    width: 300px;
}

.display {
    background: #f8f9fa;
    border-radius: 12px;
    padding: 20px;
    margin-bottom: 20px;
    text-align: right;
    font-size: 2em;
    min-height: 60px;
    word-wrap: break-word;
    color: #333;
}

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

button {
    padding: 15px;
    font-size: 1.2em;
    border: none;
    border-radius: 12px;
    background: #fff;
    color: #333;
    cursor: pointer;
    transition: all 0.3s ease;
}

button:hover {
    background: #f0f0f0;
    transform: translateY(-2px);
}

button:active {
    transform: translateY(0px);
}

.operator {
    background: #e3e3e3;
}

.equals {
    background: #007AFF;
    color: white;
}

.equals:hover {
    background: #0056b3;
}

.clear {
    background: #ff3b30;
    color: white;
}

.clear:hover {
    background: #dc1c1c;
}