body {
    background-color: #0a0a0a;
    color: white;
    font-family: 'Inter', sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
}

.converter-card {
    background: #111;
    padding: 2rem;
    border-radius: 15px;
    border: 1px solid #00f2ff;
    text-align: center;
    width: 300px;
}

input[type="number"] {
    width: 80%;
    padding: 10px;
    background: #222;
    border: 1px solid #444;
    color: #00f2ff;
    font-size: 1.2rem;
    border-radius: 5px;
    margin-bottom: 20px;
}

.radio-group {
    text-align: left;
    margin: 15px 0;
    font-size: 0.9rem;
}

button {
    background: #00f2ff;
    border: none;
    padding: 10px 20px;
    border-radius: 5px;
    font-weight: bold;
    cursor: pointer;
    width: 100%;
}

#result {
    margin-top: 20px;
    font-weight: bold;
    color: #9ca3af;
}