devkit: survey format: add dark mode support

Author: abarisain

Diff for: devkit/samples/survey/style.css

@@ -11,6 +11,19 @@
     --content-padding: 20px;
 }
 
+@media (prefers-color-scheme: dark) {
+    :root {
+        --backdrop-background-color: #1b3445;
+        --content-background-color: #191919;
+        --accent-color: #f7ede2;
+        --text-color: #dcdde3;
+        --border-color: #f7ede2;
+        --button-hover-text-color: white;
+        --button-hover-bg-color: #f7ede2;
+    }
+}
+
+
 #bottom-buttons {
     --button-bg-color: transparent;
 }
@@ -161,4 +174,10 @@ h2 {
         border-radius: 20px;
         box-shadow: 0px 15px 73px 0px rgba(0,0,0,0.65);
     }
+}
+
+@media screen and (prefers-color-scheme: dark) and (min-width: 640px) and (min-height: 640px) {
+    #content {
+        border: 1px solid #494949;
+    }
 }