Fix code copy button styling

source/css/buttons.css

@@ -87,3 +87,31 @@ a.read-more:active {
     background: none;
   }
 }
+
+.code-toolbar {
+  margin-bottom: 20px;
+
+  .toolbar-item a {
+    position: relative;
+    display: inline-flex;
+    align-items: center;
+    justify-content: center;
+    padding: 3px 8px;
+    margin-bottom: 5px;
+    background: var(--light-background-secondary);
+    text-decoration: none;
+    text-align: center;
+    font-size: 13px;
+    font-weight: 500;
+    border-radius: 8px;
+    border: 1px solid transparent;
+    appearance: none;
+    cursor: pointer;
+    outline: none;
+
+    .dark-theme & {
+      background: var(--dark-background-secondary);
+      color: inherit;
+    }
+  }
+}