.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;
}

.fcc-calculator fieldset {
    border:0;
    padding:0;
    margin:0 0 16px;
}

.fcc-calculator fieldset legend {
    color: #333;
    margin-bottom: 20px;
    font-size: 1.5rem;
}

.fcc-calculator .label-input-text {
    margin: 5px;
}

.fcc-calculator h3 {
    text-align: center;
    color: #333;
    margin-bottom: 20px;
    font-size: 1rem;
}

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

.fcc-calculator .input-text, .fcc-calculator .input-select {
    width: 95%;
    padding: 10px 12px;
    margin-bottom: 16px;
    border: 1px solid #ccc;
    border-radius: 8px;
    transition: border 0.2s;
}

.fcc-calculator input:focus {
    border-color: #4a90e2;
    outline: none;
}

.fcc-calculator .button {
    position: relative;
    margin: 0 auto;
    width: 98%;
    padding: 10px;
    border-radius: 20px;
    background-color: rgb(0, 200, 0);
    border: 1px solid rgb(0, 100, 0);
    color: rgb(255, 255, 255);
    font-weight: bold;
}

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