raspap-webgui/includes/themes.php

<?php
/**
*
*
*/
function DisplayThemeConfig()
{

    $cselected = '';
    $hselected = '';
    $tselected = '';

    switch ($_COOKIE['theme']) {
        case "custom.css":
            $cselected = ' selected="selected"';
            break;
        case "hackernews.css":
            $hselected = ' selected="selected"';
            break;
        case "terminal.css":
            $tselected = ' selected="selected"';
            break;
    }

?>
  <div class="row">
  <div class="col-lg-12">
  <div class="panel panel-primary">
  <div class="panel-heading"><i class="fa fa-wrench fa-fw"></i> <?php echo _("Change Theme"); ?></div>
  <div class="panel-body">

    <h4><?php echo _("Theme settings"); ?></h4>

    <div class="row">
      <div class="form-group col-md-6">
        <label for="code"><?php echo _("Select a theme"); ?></label>
          <select class="form-control" id="theme-select"><?php echo _("Select a Theme"); ?>
            <option value="default" class="theme-link"<?php echo $cselected; ?>>RaspAP (default)</option>
            <option value="hackernews" class="theme-link"<?php echo $hselected; ?>>HackerNews</option>
            <option value="terminal" class="theme-link"<?php echo $tselected; ?>>Terminal</option>
          </select>
      </div>
    </div>

    <form action="?page=system_info" method="POST">
      <?php echo CSRFTokenFieldTag() ?>
      <input type="button" class="btn btn-outline btn-primary" value="<?php echo _("Refresh"); ?>" onclick="document.location.reload(true)" />
    </form>

  </div><!-- /.panel-body -->
  </div><!-- /.panel-primary -->
  </div><!-- /.col-lg-12 -->
  </div><!-- /.row -->
<?php
}