* {
    box-sizing: border-box;
    margin: 1px;
    padding: 3px;
    font-family: Arial, sans-serif;
}

/* Body styling */
body {
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;
    background: linear-gradient(135deg, #f0f0f5, #b5c6e0);
}

/* Calculator container */
.calculator {
    border: 1px solid rgb(5, 5, 5);
    width: 350px;
    padding: 20px;
    border-radius: 20px;
    background: rgba(255, 255, 255, 0.1);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2), inset 0 0 10px rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(15px);
    display: flex;
    flex-direction: column;
}

/* Display styling */
.display {
    border: 2px solid rgb(5, 5, 5);
    width: 100%;
    height: 80px;
    background: rgba(255, 255, 255, 0.3);
    color: #333;
    text-align: right;
    padding: 20px;
    font-size: 2rem;
    border-radius: 15px;
    margin-bottom: 20px;
    box-shadow: inset 0 80px 8px rgba(255, 255, 255, 1.2);
}

/* Buttons container */
.buttons {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 15px;
}

/* Button styling */
.button {
    width: 100%;
    height: 70px;
    font-size: 1.5rem;
    font-weight: bold;
    color: #333;
    background: rgba(255, 255, 255, 0.2);
    border: none;
    border-radius: 15px;
    cursor: pointer;
    box-shadow: 0 12px 4px rgba(0, 0, 0, 0.15);
    transition: all 0.2s ease;

}

/* Hover and active effects */
.button:hover {
    background: rgba(255, 255, 255, 0.4);
}

.button:active {
    background: rgba(255, 255, 255, 0.6);
    box-shadow: inset 0 4px 8px rgba(0, 0, 0, 0.2);
}

/* Special buttons styling */
.button.clear {
    background-color: #e74c3c;
    color: #fff;
    grid-column: span 2;
}

.button.equals {
    background-color: #2ecc71;
    color: #fff;
    grid-column: span 2;
}

.button.operator {
    background-color: #3498db;
    color: #fff;
}