support dark mode

src/App.vue

@@ -46,4 +46,29 @@ export default {
 footer {
   text-align: center;
 }
+
+* {
+  background-color: whitesmoke;
+  color: black;
+}
+
+a, a:link, a:visited, a:focus, a:hover, a:active {
+  color: steelblue;
+}
+
+a:focus, a:hover, a:active {
+  box-shadow: inset 0 0 100px 100px rgba(255, 255, 255, 0.2);
+}
+
+@media (prefers-color-scheme: dark) {
+  * {
+    background-color: darkslategray;
+    color: white;
+  }
+
+  a, a:link, a:visited, a:focus, a:hover, a:active {
+    color: lightsteelblue;
+  }
+
+}
 </style>