Use CSS nesting, add caption adjustment

Author: Techassi

src/css/admonition.css

@@ -1,14 +1,21 @@
-/* Apply padding-top only for admonitions which only contain a code block */
-.doc .admonitionblock.code-rule td.content:has(div.listingblock) {
-  padding: 1rem 0 0 0 !important;
-}
+.doc .admonitionblock.code-rule {
+  /* Apply padding-top only for admonitions which only contain a code block */
+  & td.content:has(div.listingblock) {
+    padding: 1rem 0 0 0 !important;
+  }
 
-/* Disable box shadow for code blocks inside code rule admonitions */
-.doc .admonitionblock.code-rule td.content div.listingblock pre.highlight code {
-  box-shadow: none;
-}
+  /* Disable box shadow for code blocks inside code rule admonitions */
+  & td.content div.listingblock pre.highlight code {
+    box-shadow: none;
+  }
 
-/* Change color of the "important" admonition back to the default red */
-.doc .admonitionblock.code-rule td.icon i.icon-important {
-  background-color: #e40046;
-}
+  /* Change color of the "important" admonition back to the default red */
+  & td.icon i.icon-important {
+    background-color: #e40046;
+  }
+
+  /* Don't use uppercase for captions */
+  & .icon {
+    text-transform: none;
+  }
+}