.pde-checker {
    margin: 15px 0;
}
.pde-checker input {
    padding: 6px;
    width: 150px;
    margin-right: 5px;
}
.pde-checker button {
    padding: 6px 10px;
    cursor: pointer;
}
#pde-result {
    margin-top: 10px;
    font-weight: bold;
}