Redesign UI with modern dark theme and improved styling

- Unified color scheme using CSS variables across all pages
- Fixed spacing issues in verse display (removed <br> joins for rich view)
- Updated all HTML pages with proper HTML5 structure
- Added responsive design with mobile breakpoints
- Created shared stylesheet (styles/page.css) for form pages
- Fixed unclosed div tag in scripture_response
- Improved typography with serif fonts for scripture text
- Added verse container cards with hover effects
- Inline dark background to prevent white flash on navigation

All endpoints remain backward compatible with existing functionality.

styles/collapsible.css

@@ -1,25 +1,54 @@
-/* Style the button that is used to open and close the collapsible content */
+/* Modern Collapsible Styling */
+
 .collapsible {
-  background-color: #eee;
-  color: #444;
+  background-color: #2f2f2f;
+  color: #e8e8e8;
   cursor: pointer;
-  padding: 18px;
+  padding: 1rem 1.25rem;
   width: 100%;
-  border: none;
+  max-width: 820px;
+  border: 2px solid #3a3a3a;
+  border-radius: 4px;
   text-align: left;
   outline: none;
-  font-size: 15px;
+  font-size: 1rem;
+  font-weight: 600;
+  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
+  transition: background-color 150ms ease, border-color 150ms ease, transform 150ms ease;
+  margin: 0.5rem auto;
+  display: block;
 }
 
-/* Add a background color to the button if it is clicked on (add the .active class with JS), and when you move the mouse over it (hover) */
-.active, .collapsible:hover {
-  background-color: #ccc;
+.collapsible:hover {
+  background-color: #3a3a3a;
+  border-color: #6b9bd1;
+  transform: translateY(-1px);
 }
 
-/* Style the collapsible content. Note: hidden by default */
+.collapsible.active {
+  background-color: #6b9bd1;
+  color: #1a1a1a;
+  border-color: #6b9bd1;
+}
+
+.collapsible.active:hover {
+  background-color: #85aede;
+  border-color: #85aede;
+}
+
+/* Collapsible content styling */
 .content {
-  padding: 0 18px;
+  padding: 0 1.25rem;
   display: none;
   overflow: hidden;
-  background-color: #f1f1f1;
+  background-color: #252525;
+  max-width: 820px;
+  margin: 0 auto 0.5rem;
+  border-radius: 4px;
+  border: 1px solid #3a3a3a;
+}
+
+.content.show {
+  display: block;
+  padding: 1rem 1.25rem;
 }