Lighten dark mode gradients from brand-700/800 to brand-600

- Hero dark gradient start: brand-700 → brand-600
- Blog SVG image background fill: brand-800 → brand-600
- BlogCard grid gradient end: brand-800 → brand-600
- ArticleHero gradient end: brand-800 → brand-600

https://claude.ai/code/session_019mp7rTrQPx9yxp17hgjsYb

src/components/blog/ArticleHero.astro

@@ -109,7 +109,7 @@ const readingTime = Math.max(1, Math.ceil(estimatedWords / wordsPerMinute));
       {svgSlug ? (
         <div
           class="relative overflow-hidden rounded-xl border border-border shadow-2xl
-            bg-gradient-to-br from-brand-100/50 to-brand-50/30 dark:from-brand-900/50 dark:to-brand-800/30"
+            bg-gradient-to-br from-brand-100/50 to-brand-50/30 dark:from-brand-900/50 dark:to-brand-600/30"
           style="color: var(--brand-500);"
         >
           <BlogImageSVG slug={svgSlug} title={imageAlt || title} />

src/components/blog/BlogCard.astro

@@ -39,7 +39,7 @@ const readingTime = Math.max(1, Math.ceil(estimatedWords / wordsPerMinute));
   <a href={href} class="block">
     <div
       class="relative mb-4 overflow-hidden rounded-md
-        bg-background-secondary bg-gradient-to-br from-brand-100/65 to-transparent dark:from-brand-900/60 dark:to-brand-800/25"
+        bg-background-secondary bg-gradient-to-br from-brand-100/65 to-transparent dark:from-brand-900/60 dark:to-brand-600/25"
       style="color: var(--brand-500);"
     >
       {svgSlug ? (

src/components/blog/BlogImageSVG.astro

@@ -44,7 +44,7 @@ const svgContent = svgs[`/src/assets/blog/${slug}.svg`] ?? '';
   /* ── Dark mode ───────────────────────────────────────────────────────────
      Deep background with all brand colors at full opacity — vivid, not faded.
   ── */
-  :global(html.dark) .svg-host :global(.bg)  { fill: var(--brand-800); }
+  :global(html.dark) .svg-host :global(.bg)  { fill: var(--brand-600); }
   :global(html.dark) .svg-host :global(.ico) { stroke: var(--brand-200); }
   :global(html.dark) .svg-host :global(.txt) { fill: var(--brand-50); }
   :global(html.dark) .svg-host :global(.ln)  { stroke: var(--brand-300); stroke-opacity: 0.5; }