Fix alternating section background pattern

Dark/Medium pattern:
- Hero: dark
- Animation: medium
- Demo: dark
- Features: medium
- How It Works: dark
- Formats: medium
- Download: dark

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

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: iYassr

docs/index.html

@@ -217,7 +217,6 @@
     /* Demo Section */
     .demo {
       padding: 100px 0;
-      background: var(--bg-medium);
     }
 
     .section-title {
@@ -250,6 +249,7 @@
     /* Features */
     .features {
       padding: 100px 0;
+      background: var(--bg-medium);
     }
 
     .features-grid {
@@ -295,7 +295,6 @@
     /* How It Works */
     .how-it-works {
       padding: 100px 0;
-      background: var(--bg-medium);
     }
 
     .steps {
@@ -347,6 +346,7 @@
     /* Formats */
     .formats {
       padding: 100px 0;
+      background: var(--bg-medium);
     }
 
     .formats-table {
@@ -390,7 +390,6 @@
     /* Download */
     .download {
       padding: 100px 0;
-      background: var(--bg-medium);
       text-align: center;
     }