widget: input the px value from user and use it as inline style in widget function

Googled some more and found out that closing php tags and writing html as it is a better practice as compared to writing html inside. Made the following changes to the code shared above:

    $space=200px;
    ?>
      <div style="margin-bottom:<?php echo $space; ?>" >
    <?php
      //rest of the code
    ?>
      </div>
    <?php
      //rest of the code

Space between widgets added!