Replace ASCII art banners with mobile-responsive headers

- Replace fixed-width ASCII banners with CSS-styled section headers
- Add responsive styling for mobile devices
- Update home page, event pages, header and footer layouts
- Improve mobile experience with scalable headers and gradient dividers

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

static/css/style.css

@@ -162,13 +162,62 @@ a:hover {
   font-weight: bold;
 }
 
-/* ASCII art borders */
+/* Section headers */
+.section-header {
+  text-align: center;
+  margin: 2rem 0;
+  position: relative;
+}
+
+.section-header h2 {
+  color: var(--neon-green);
+  text-shadow: 0 0 10px var(--neon-green);
+  font-size: 1.8rem;
+  text-transform: uppercase;
+  letter-spacing: 3px;
+  border: 2px solid var(--neon-green);
+  padding: 1rem 2rem;
+  background: rgba(0, 255, 65, 0.1);
+  border-radius: 5px;
+  margin: 0;
+}
+
+.section-header h3 {
+  color: var(--neon-blue);
+  text-shadow: 0 0 10px var(--neon-blue);
+  font-size: 1.4rem;
+  text-transform: uppercase;
+  letter-spacing: 2px;
+  border: 2px solid var(--neon-blue);
+  padding: 0.8rem 1.5rem;
+  background: rgba(0, 212, 255, 0.1);
+  border-radius: 5px;
+  margin: 0;
+}
+
+/* Header and footer dividers */
+.header-divider, .footer-divider {
+  height: 2px;
+  background: linear-gradient(90deg, transparent, var(--neon-green), transparent);
+  margin: 1rem 0;
+  box-shadow: 0 0 10px var(--neon-green);
+}
+
+/* ASCII art borders - fallback for existing usage */
 .ascii-border {
   font-family: monospace;
   color: var(--neon-green);
   text-align: center;
   margin: 1rem 0;
   font-size: 0.8rem;
+  overflow-x: auto;
+}
+
+.ascii-border pre {
+  margin: 0;
+  white-space: pre;
+  overflow-x: auto;
+  min-width: fit-content;
 }
 
 /* Event detail page styles */
@@ -227,4 +276,29 @@ a:hover {
   .event-meta {
     grid-template-columns: 1fr;
   }
+  
+  /* Mobile-friendly section headers */
+  .section-header h2 {
+    font-size: 1.2rem;
+    letter-spacing: 1px;
+    padding: 0.8rem 1rem;
+  }
+  
+  .section-header h3 {
+    font-size: 1rem;
+    letter-spacing: 1px;
+    padding: 0.6rem 0.8rem;
+  }
+  
+  /* Mobile-friendly ASCII borders */
+  .ascii-border {
+    font-size: 0.6rem;
+    margin: 0.5rem 0;
+  }
+  
+  .ascii-border pre {
+    padding: 0.5rem;
+    transform: scale(0.8);
+    transform-origin: center;
+  }
 }