body {
    font-family: Arial, sans-serif;
    display: flex;
    justify-content: center;
    align-items: center;
    min-height: 100vh;

    background-image: url(https://toppng.com/uploads/preview/road-man-run-asphalt-jog-11569972622q56jeco317.jpg);
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
}

.converter-card {
    background-color: rgba(255, 255, 255, 0.75);
    backdrop-filter: blur(6px);
    padding: 40px;
    border-radius: 16px;
    box-shadow: 0 10px 25px rgba(0,0,0,0.2);
    text-align: center;
    width: 90%;
    max-width: 420px;
}

h1 {
    color: #1f2a44;
    margin-bottom: 25px;
}

input[type="text"],
input[type="number"],
select {
    padding: 12px;
    width: 100%;
    margin: 10px 0;
    border-radius: 8px;
    border: 1px solid #ccc;
    font-size: 16px;
    box-sizing: border-box;
}

input:focus,
select:focus {
    outline: none;
    border: 2px solid #d62828;
}

/* Button */
button {
    padding: 12px 25px;
    font-size: 16px;
    border-radius: 8px;
    border: none;
    background-color: #d62828;
    color: white;
    cursor: pointer;
    transition: all 0.25s ease;
    box-shadow: 0 5px 15px rgba(0,0,0,0.2);
}

button:hover {
    background-color: #b71c1c;
    transform: translateY(-2px);
}

/* Result */
#result {
    margin-top: 20px;
    font-size: 20px;
    font-weight: bold;
    color: #2a9d8f;
}

details {
    margin-top: 20px;
    font-size: 14px;
    text-align: left;
}

details summary {
    font-weight: bold;
    color: #1f2a44;
    cursor: pointer;
}