style(markdown): adjust link styling and dark mode text color

- Modify dark mode fourth text color for better contrast
- Adjust padding for links in markdown content
- Add specific styling for elements with 'link' class

source/css/common/colors.styl

@@ -73,7 +73,7 @@ $dark-invert-text-color = #373D3F
 $dark-first-text-color = lighten($dark-default-text-color, 30%)
 $dark-second-text-color = lighten($dark-default-text-color, 20%)
 $dark-third-text-color = darken($dark-default-text-color, 20%)
-$dark-fourth-text-color = darken($dark-default-text-color, 80%)
+$dark-fourth-text-color = darken($dark-default-text-color, 60%)
 $dark-border-color = rgba(255, 255, 255, 0.08)
 $dark-selection-color = $selection-color
 $dark-shadow-color-1 = rgba(255, 255, 255, 0.08)

source/css/common/markdown.styl

@@ -31,11 +31,13 @@
     // border-bottom 1px solid var(--third-text-color)
     box-sizing border-box
     padding-bottom 2px
-    padding-right 0.2em
     text-underline-offset 2px
     text-decoration-color var(--fourth-text-color)
     transition: text-decoration-color 0.2s ease
 
+    &.link
+      padding-right 0.1em
+
     .fas, .far, fab
       margin 0 2px 0 6px
       position relative