fix(api-docs): sidebar on landing, glow at top, kill header band/divider (#28)

- Drop 'template: splash' on the index so the landing page gets the standard
  left sidebar (search + page tree) + right TOC, like the doc pages.
- Make the aurora glow start at the very top of the page and be clearly visible
  (was pushed off-screen + too faint).
- Remove Starlight's full-width header BAND — its solid dark background +
  bottom border were blocking the glow and drawing a header/body divider. Only
  the floating pill remains.

Co-authored-by: mavneox <mav@onlywithneo.com>
Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

Author: 3 people

src/content/docs/index.mdx

@@ -1,7 +1,6 @@
 ---
 title: GEN API & MCP
 description: Drive GEN from your code or from Claude Code. Mint an API token, connect the MCP server, and automate the whole content workflow.
-template: splash
 hero:
   tagline: Drive GEN from your own code — or straight from Claude Code. Mint an API token, connect the MCP server, and automate the whole content workflow in minutes.
   actions:

src/styles/custom.css

@@ -69,17 +69,17 @@
  * each blob drifts on its own keyframe, blurred + screen-blended. */
 .gen-aurora {
   position: fixed;
-  top: -300px;
+  top: -120px;             /* glow starts right at the top of the page */
   left: -5%;
   right: -5%;
-  height: 560px;            /* contained band at the very top */
+  height: 660px;
   z-index: 0;
   pointer-events: none;
-  filter: blur(80px) saturate(135%);
-  opacity: 0.6;
+  filter: blur(75px) saturate(140%);
+  opacity: 0.95;           /* clearly visible glow */
   /* fade the bottom edge so the glow doesn't spill DOWN the page/sidebar */
-  -webkit-mask-image: linear-gradient(180deg, #000 55%, transparent 100%);
-  mask-image: linear-gradient(180deg, #000 55%, transparent 100%);
+  -webkit-mask-image: linear-gradient(180deg, #000 48%, transparent 100%);
+  mask-image: linear-gradient(180deg, #000 48%, transparent 100%);
 }
 .gen-aurora span {
   position: absolute;
@@ -110,6 +110,16 @@
  * sidebar clear it (the sidebar starts at --sl-nav-height). */
 :root { --sl-nav-height: 7rem; }
 
+/* Kill Starlight's full-width header BAND — its solid dark background + bottom
+ * border are what block the top glow and draw a line between header and body.
+ * Our floating pill (.gen-header) is the only header chrome we want. */
+.header {
+  background-color: transparent !important;
+  background: transparent !important;
+  border-bottom: none !important;
+  backdrop-filter: none !important;
+}
+
 /* Search box pinned to the TOP of the left sidebar (Sidebar.astro override). */
 .gen-sidebar-search {
   margin: 0 0 1rem;