.fcc-calculator {
    background: #fff;
    padding: 30px;
    border-radius: 12px;
    box-shadow: 0 6px 20px rgba(0,0,0,0.1);
    max-width: 400px;
    margin: 20px auto;
    font-family: 'Segoe UI', sans-serif;
}

.fcc-calculator h2 {
    text-align: center;
    color: #333;
    margin-bottom: 20px;
    font-size: 1.5rem;
}

.fcc-calculator label {
    display: block;
    margin-bottom: 6px;
    font-weight: 600;
    color: #555;
}

.fcc-calculator input[type="number"] {
    width: 100%;
    padding: 10px 12px;
    margin-bottom: 16px;
    border: 1px solid #ccc;
    border-radius: 8px;
    font-size: 1rem;
    transition: border 0.2s;
}

.fcc-calculator input[type="number"]:focus {
    border-color: #4a90e2;
    outline: none;
}

.fcc-output {
    text-align: center;
    font-size: 1.25rem;
    font-weight: 600;
    color: #4a90e2;
    margin-top: 20px;
}