fix(style): improve search dialog contrast

Overrides Pagefind UI CSS variables and targets the result excerpt directly to ensure readable text contrast in both light and dark modes.

src/styles/style.css

@@ -154,11 +154,21 @@ site-search button[data-open-modal] {
   color: var(--primary-color) !important;
 }
 
+#starlight__search {
+  --pagefind-ui-text: var(--primary-color);
+  --pagefind-ui-primary: var(--witch-rose);
+}
+
 #starlight__search input::placeholder {
   color: var(--primary-color) !important;
   opacity: 0.8;
 }
 
+.pagefind-ui__result-excerpt {
+  color: var(--primary-color) !important;
+  opacity: 0.9;
+}
+
 #extra-footer-content {
   display: flex;
   flex-direction: row;