@keyframes gradient {
    0% {
        background-position: 0% 50%;
    }
    50% {
        background-position: 100% 50%;
    }
    100% {
        background-position: 0% 50%;
    }
}



body {
    font-family: 'Arial', sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
    background: linear-gradient(-45deg, #ee7752, #e73c7e, #23a6d5, #23d5ab);
    background-size: 400% 400%;
    animation: gradient 15s ease infinite;
}

.calculator {
    width: auto;
    background-color: rgba(255, 255, 255, 0.8); /* Semi-transparent white */
    padding: 25px;
    border-radius: 8px;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.05);
    display: inline-block;
}

input[type="text"] {
    width: 240px;
    padding: 8px;
    margin: 10px 0;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 20px;
    text-align: right;
    background-color: #f8f8f8;
}

.buttons {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 10px;
    padding: 10px 0;
}

button {
    padding: 15px 0;
    border: none;
    border-radius: 5px;
    font-size: 16px;
    cursor: pointer;
    background-color: #e7e7e7;
    box-shadow: 0 2px 5px rgba(0,0,0,0.1);
    transition: background-color 0.3s, box-shadow 0.3s;
}

button:hover {
    background-color: #d7d7d7;
    box-shadow: 0 5px 15px rgba(0,0,0,0.2);
}

button:active {
    box-shadow: 0 1px 3px rgba(0,0,0,0.2);
    background-color: #ccc;
}

button.operator {
    background-color: #4CAF50;
    color: white;
}

button.operator:hover {
    background-color: #45a049;
}

button.clear, button.equals {
    background-color: #f44336;
    color: white;
}

button.clear:hover, button.equals:hover {
    background-color: #d32f2f;
}