Remove scroll-to-top button

Removed the floating scroll-to-top button that appeared in the bottom-right
corner of pages after scrolling down.

Changes:
- Removed .scroll-to-top CSS styles from static/style.css
- Removed initScrollToTop() function from static/app.js
- Removed function call from initialization
- Cleaned up dark mode styles for scroll-to-top

The scroll-to-top functionality is still available via keyboard (Home key)
and browser default behavior.

static/app.js

@@ -68,33 +68,6 @@ if (document.readyState === 'loading') {
     initRelativeTimestamps();
 }
 
-// Scroll to top button functionality
-function initScrollToTop() {
-    const scrollButton = document.createElement('button');
-    scrollButton.className = 'scroll-to-top';
-    scrollButton.innerHTML = '↑';
-    scrollButton.setAttribute('aria-label', 'Scroll to top');
-    scrollButton.title = 'Scroll to top';
-    document.body.appendChild(scrollButton);
-    
-    // Show/hide button based on scroll position
-    window.addEventListener('scroll', () => {
-        if (window.pageYOffset > 300) {
-            scrollButton.classList.add('visible');
-        } else {
-            scrollButton.classList.remove('visible');
-        }
-    });
-    
-    // Scroll to top when clicked
-    scrollButton.addEventListener('click', () => {
-        window.scrollTo({
-            top: 0,
-            behavior: 'smooth'
-        });
-    });
-}
-
 // Keyboard shortcuts
 function initKeyboardShortcuts() {
     document.addEventListener('keydown', (e) => {
@@ -128,8 +101,7 @@ function initKeyboardShortcuts() {
 
 // Add form submission handlers
 document.addEventListener('DOMContentLoaded', () => {
-    // Initialize scroll to top and keyboard shortcuts
-    initScrollToTop();
+    // Initialize keyboard shortcuts
     initKeyboardShortcuts();
     
     // Handle all form submissions

static/style.css

@@ -488,38 +488,22 @@ p.thread-info {
     content: "← ";
 }
 
-/* Scroll to top button */
-.scroll-to-top {
-    position: fixed;
-    bottom: 30px;
-    right: 30px;
-    width: 50px;
-    height: 50px;
-    background-color: #001858;
-    color: #fef6e4;
-    border: 2px solid #001858;
+/* Loading spinner */
+.spinner {
+    display: inline-block;
+    width: 16px;
+    height: 16px;
+    border: 3px solid #fef6e4;
+    border-top: 3px solid #001858;
     border-radius: 50%;
-    cursor: pointer;
-    opacity: 0;
-    visibility: hidden;
-    transition: opacity 0.3s ease, visibility 0.3s ease, transform 0.2s ease;
-    z-index: 1000;
-    display: flex;
-    align-items: center;
-    justify-content: center;
-    font-size: 1.5em;
-    font-weight: bold;
+    animation: spin 0.8s linear infinite;
+    margin-left: 8px;
+    vertical-align: middle;
 }
 
-.scroll-to-top.visible {
-    opacity: 0.8;
-    visibility: visible;
-}
-
-.scroll-to-top:hover {
-    opacity: 1;
-    transform: translateY(-3px);
-    background-color: #8bd3dd;
+@keyframes spin {
+    0% { transform: rotate(0deg); }
+    100% { transform: rotate(360deg); }
 }
 
 @media (prefers-color-scheme: dark) {
@@ -545,34 +529,6 @@ p.thread-info {
         background-color: #8bd3dd;
         color: #001858;
     }
-    
-    .scroll-to-top {
-        background-color: #fef6e4;
-        color: #001858;
-        border-color: #fef6e4;
-    }
-    
-    .scroll-to-top:hover {
-        background-color: #8bd3dd;
-    }
-}
-
-/* Loading spinner */
-.spinner {
-    display: inline-block;
-    width: 16px;
-    height: 16px;
-    border: 3px solid #fef6e4;
-    border-top: 3px solid #001858;
-    border-radius: 50%;
-    animation: spin 0.8s linear infinite;
-    margin-left: 8px;
-    vertical-align: middle;
-}
-
-@keyframes spin {
-    0% { transform: rotate(0deg); }
-    100% { transform: rotate(360deg); }
 }
 
 /* Loading state for buttons */