Improve text visibility in atom and dusk themes

- Add CSS variable support to dusk theme components for dynamic text colors
- Fix low-contrast preset color combinations (cyberpunk, neon, magma, forest, obsidian, space)
- Add text-shadow utility classes and apply to site header and backgrounds
- Style logout buttons as proper buttons matching other button styles
- Fix hardcoded text colors in atom theme components

resources/themes/atom/views/layouts/app.blade.php

@@ -105,9 +105,21 @@
  /* Spinner */
  --spinner-color: {{ setting('spinner_color', '#eeb425') }};
 
- /* Navbar */
- --navbar-height: {{ setting('navbar_height', '64') }}px;
- }
+  /* Navbar */
+  --navbar-height: {{ setting('navbar_height', '64') }}px;
+  }
+
+  /* Text shadow for readability on the site background */
+  .site-bg {
+    text-shadow: 0 1px 2px rgba(0,0,0,0.3);
+  }
+  .site-bg [class*="bg-"],
+  .site-bg [class*="rounded"],
+  .site-bg [style*="background"],
+  .site-bg .swiper-slide,
+  .site-bg img {
+    text-shadow: none;
+  }
 
  /* Button Effects */
  @keyframes sparkle {