#length-converter {
    max-width: 50%;
    width: 100%;
    margin: 25px auto;
    padding: 25px;
    border: 1px solid #999;
    border-radius: 15px;
    background-color: #e0e0e0;
}
#length-converter h2 {
    text-align: center;
    color: #0056b3;
    margin-bottom: 15px;
    font-size: 1.5em;
    font-weight: bold;
    line-height: 1em;
}
#calcBtn-blue, #calcBtn-grey {
    display: block;
    width: 100%;
    padding: 12px 20px;
    border: none;
    border-radius: 8px;
    font-size: 1.1em;
    cursor: pointer;
    transition: all 0.3s ease;
    font-weight: bold;
    color: white;
}
#calcBtn-blue {
    background: linear-gradient(45deg, #007bff, #0056b3);
    box-shadow: 0 4px 10px rgba(0,123,255,0.3);
    margin-top: 25px;
}
#calcBtn-grey {
    background: linear-gradient(45deg, #6C757D, #687178);
    box-shadow: 0 4px 10px rgba(95,102,109,0.3);
    margin-top: 10px;
}
#calcBtn-blue:hover {
    background: linear-gradient(45deg, #0056b3, #003f7f);
    box-shadow: 0 6px 15px rgba(0,123,255,0.4);
    transform: translateY(-2px);
}
#calcBtn-grey:hover {
    background: linear-gradient(45deg, #687178, #5F666D);
    box-shadow: 0 6px 15px rgba(95,102,109,0.4);
    transform: translateY(-2px);
}
input[type="number"], select {
    width: 100%;
    padding: 10px;
    margin-bottom: 10px;
    border: 1px solid #ccc;
    border-radius: 5px;
    box-sizing: border-box;
    font-size: 1em;
    background-color: white;
}
#lengthResults {
    display: none;
    margin-top: 20px;
    border: 2px solid #007bff;
    padding: 15px;
    border-radius: 10px;
    background-color: #fff;
}