Replace random HSL gradients in homepage cards with header gradient

public/index.php

@@ -48,12 +48,7 @@ extract($vars);
                                      loading="lazy">
                             </figure>
                         <?php else: ?>
-                            <?php
-                            $hue  = ($item['id'] * 47 + 160) % 360;
-                            $hue2 = ($hue + 40) % 360;
-                            ?>
                             <div class="card__media--gradient"
-                                 style="background:linear-gradient(135deg,hsl(<?= $hue ?>,55%,40%),hsl(<?= $hue2 ?>,50%,28%));"
                                  aria-hidden="true">
                                 <span class="card__gradient-author"><?= htmlspecialchars($item['authors'] ?? '') ?></span>
                                 <span class="card__gradient-title"><?= htmlspecialchars($item['title']) ?></span>