[web-client] simple theme: move sources to client/simple/src

Signed-off-by: Markus Heiser <markus.heiser@darmarit.de>

client/simple/src/less/rss.less

@@ -0,0 +1,45 @@
+@import (inline) "../../node_modules/normalize.css/normalize.css";
+@import "definitions.less";
+
+.text-size-adjust (@property: 100%) {
+  -webkit-text-size-adjust: @property;
+  -ms-text-size-adjust: @property;
+  -moz-text-size-adjust: @property;
+  text-size-adjust: @property;
+}
+
+// Reset padding and margin
+html,
+body,
+main {
+  padding: 0;
+  margin: 0;
+}
+
+html {
+  font-family: sans-serif;
+  font-size: 0.9em;
+  .text-size-adjust;
+
+  color: var(--color-base-font);
+  background-color: var(--color-base-background);
+
+  scroll-behavior: smooth;
+}
+
+body {
+  margin-inline: 1rem;
+}
+
+a {
+  text-decoration: none;
+  color: var(--color-url-font);
+
+  &:visited {
+    color: var(--color-url-visited-font);
+
+    .highlight {
+      color: var(--color-url-visited-font);
+    }
+  }
+}