Update elements.css with dark mode

(cherry picked from commit e14e996)

static/elements.css

@@ -29,4 +29,9 @@ position:absolute;right:0;top:0;image-rendering:pixelated;background-size:contai
 .post-box .post-author{display:none}
 .post-box .post-dot{display:none}
 .post-box .post-title{display:inline-block;margin:0;font-style:normal;font-family:inherit}
-
+@media (prefers-color-scheme: dark) {
+  .follow{
+display:block;color:white;border-radius:25px;padding:8px 16px;background-color:#1f384a;text-decoration:none !important;
+margin-bottom:5px;border:none;width:100%;text-align:left;font-size:16px
+}
+  .follow:hover{background:#28465c;}