Fix text readability and remove black margin using pseudo-element overlay

Co-authored-by: ulysses4ever <[email protected]>

Author: Copilot

docs/assets/css/dark-mode.css

@@ -137,13 +137,26 @@ body.dark-mode {
 body.dark-mode #newsplash {
     color: #e0e0e0;
     background-color: #1a1a1a !important;
-    /* Dim the background image instead of hiding it */
-    filter: brightness(0.4) contrast(1.2);
+    position: relative;
 }
 
-/* Prevent filter from affecting child elements */
+/* Add a dark overlay using pseudo-element to dim background while keeping text readable */
+body.dark-mode #newsplash::before {
+    content: "";
+    position: absolute;
+    top: 0;
+    left: 0;
+    right: 0;
+    bottom: 0;
+    background-color: rgba(26, 26, 26, 0.65);
+    pointer-events: none;
+    z-index: 0;
+}
+
+/* Ensure content is above the overlay */
 body.dark-mode #newsplash > div {
-    filter: brightness(2.5) contrast(0.83);
+    position: relative;
+    z-index: 1;
 }
 
 body.dark-mode .newsplash a.nostarchlink {