scss: add a bottom border to post-infos content

- Adds a bottom border to post-infos content to improve readability.
- Improves the boder rules to comply with the proposed order of the
  border specification (width, style, color).

Co-Authored-by: iGor milhit <igor@milhit.ch>

assets/scss/_lists.scss

@@ -4,6 +4,8 @@
 //               //
 ///////////////////
 
+@use "@picocss/pico/scss/colors/index" as *;
+
 /* Lists of posts (like in categories page) */
 .posts-list {
   display: flex;
@@ -60,7 +62,7 @@
   }
 
   ul {
-    padding: 0;
+    padding: 0 0 calc(var(--pico-spacing)/1) 0;
 
   }
 
@@ -79,6 +81,11 @@
       white-space: pre;
     }
   }
+
+}
+
+details[open] > ul {
+  border-bottom: var(--pico-border-width) solid $purple-200;
 }
 
 @media (min-width: 576px) {

assets/scss/_medias.scss

@@ -9,7 +9,7 @@
 
 .audio,
 .stream {
-  border: $purple-200 solid var(--pico-border-width);
+  border: var(--pico-border-width) solid $purple-200 ;
 
   audio {
     border-radius: var(--pico-border-radius);
@@ -60,7 +60,7 @@ figure {
   border-radius: var(--pico-border-radius);
   margin: var(--pico-spacing) auto;
   padding: .4em;
-  border: $purple-200 solid var(--pico-border-width);
+  border: var(--pico-border-width) solid $purple-200 ;
   width: 80%;
 
   img {