body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: #f2f4f8;
    padding: 20px;
}

.calculator-container {
    background: white;
    border-radius: 20px;
    padding: 40px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    text-align: center;
    max-width: 400px;
    margin: auto;
    animation: fadeIn 1s ease-in-out;
}

h1 {
    font-size: 28px;
    margin-bottom: 10px;
    color: #333;
}

.description {
    font-size: 14px;
    color: #555;
    margin-bottom: 30px;
}

.calculator label {
    display: block;
    text-align: left;
    margin-bottom: 5px;
    color: #444;
}

.calculator input {
    width: 100%;
    padding: 10px;
    margin-bottom: 20px;
    border: 1px solid #ccc;
    border-radius: 8px;
    font-size: 16px;
}

button {
    width: 100%;
    padding: 12px;
    background-color: #66a6ff;
    color: white;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    cursor: pointer;
    transition: background-color 0.3s ease;
}

button:hover {
    background-color: #558de8;
}

#result {
    margin-top: 20px;
    font-size: 18px;
    font-weight: bold;
    color: #333;
}

@keyframes fadeIn {
    from { opacity: 0; transform: translateY(-20px); }
    to { opacity: 1; transform: translateY(0); }
}