style(site): truly centred navbar, smoother logo docking, grain on logos and buttons, slashed title underlines

site/includes/navbar.php

@@ -14,7 +14,7 @@ $logo_dims = svg_img_dims_attr(dirname(__DIR__, 2) . '/' . $logo_rel);
 $center_logo = !empty($nav_center_logo);
 ?>
 <header class="header-section lazy<?= $center_logo ? ' has-center-logo is-top' : '' ?>">
-  <nav class="navbar navbar-expand-lg navbar-light" style="padding-left:1rem; padding-top: 0; padding-bottom: 0;padding-right: 0; ">
+  <nav class="navbar navbar-expand-lg navbar-light">
       <a class="navbar-brand" href="<?= htmlspecialchars(gym_url(current_gym())) ?>">
       <?php if (img_fallback_rel($logo_rel) !== ''): ?>
       <?= img_tag($logo_rel, ['loading' => 'eager', 'decoding' => 'async', 'alt' => 'Logo ' . (current_gym()['name'] ?? 'FitMe 3070')]) ?>