Add theme to loading gradient, comment form, about author (#2117)

app/assets/stylesheets/article-show.scss

@@ -600,9 +600,11 @@ article {
     overflow: hidden;
     padding: 0px 0px 5px;
     background: white;
+    background: var(--theme-container-background, white);
     font-family: $helvetica;
     a {
       color: $black;
+      color: var(--theme-color, $black);
     }
     @media screen and (min-width: 520px) {
       width: 82%;
@@ -660,14 +662,18 @@ article {
         font-size: 0.85em;
         a {
           color: $medium-gray;
+          color: var(--theme-secondary-color, $medium-gray);
           margin-right: 6px;
           display: inline-block;
           .icon-img {
             width: 15px;
             height: 15px;
+            border-radius: 3px;
             vertical-align: -2px;
             margin: 0px;
             opacity: 0.7;
+            background: transparent;
+            background: var(--theme-secondary-color, transparent);
           }
         }
       }

app/assets/stylesheets/articles.scss

@@ -1555,6 +1555,7 @@
 }
 
 .single-article-loading {
+  border-radius: 3px;
   @extend .animated-background;
 }
 
@@ -1575,6 +1576,7 @@
   animation-timing-function: linear;
   background: #f6f6f6;
   background: linear-gradient(to right, #f6f6f6 8%, #f0f0f0 18%, #f6f6f6 33%);
+  background: var(--theme-gradient-background, linear-gradient(to right, #f6f6f6 8%, #f0f0f0 18%, #f6f6f6 33%));
   background-size: 800px 104px;
   position: relative;
 }

app/assets/stylesheets/comments.scss

@@ -219,6 +219,7 @@ a.header-link {
   form {
     width: 104%;
     background: $light-gray;
+    background: var(--theme-container-background, $light-gray);
     overflow: auto;
     position: relative;
     margin-bottom: 4px;

app/views/layouts/application.html.erb

@@ -98,6 +98,7 @@
           --theme-container-background: #27374c;\
           --theme-container-accent-background: #384b66;\
           --theme-container-background-hover: #37475c;\
+          --theme-gradient-background: linear-gradient(to right, #293d56 8%, #282833 18%, #293d56 33%);\
           --theme-container-color: #fff;\
           --theme-container-box-shadow: none;\
           --theme-container-border: 1px solid #141d26;</style>'