enhancement: Refine Dark Theme Markdown Text Color Consistency (#8772)

Author: tobiu

resources/scss/src/component/Markdown.scss

@@ -1,6 +1,7 @@
 .neo-markdown-component {
     background-color: var(--markdown-bg);
     border-radius   : 8px;
+    color           : var(--markdown-text-color);
     letter-spacing  : 1px;
     margin          : 0 auto;
     max-width       : 1200px;

resources/scss/theme-neo-dark/component/Markdown.scss

@@ -15,4 +15,5 @@
     --markdown-pre-border           : var(--sem-color-border-subtle);
     --markdown-table-border         : var(--sem-color-border-subtle);
     --markdown-table-header-bg      : var(--purple-900);
+    --markdown-text-color           : var(--white-off);
 }

resources/scss/theme-neo-light/component/Markdown.scss

@@ -15,4 +15,5 @@
     --markdown-pre-border           : lightgray;
     --markdown-table-border         : lightgray;
     --markdown-table-header-bg      : #f8f8f8;
+    --markdown-text-color           : var(--sem-color-text-neutral-default);
 }