fix: version warning display (#130)

Author: kratsg

docs/_static/css/custom.css

@@ -1,3 +1,51 @@
 .highlight-latex pre {
   white-space: pre-wrap !important;
 }
+
+/* 1200px for slightly wider for most monitors */
+.wy-nav-content {
+  max-width: 1200px !important;
+}
+
+/* version warning badge */
+#dev-version {
+  display: none;
+}
+
+#dev-version.version-warning {
+  display: block;
+}
+
+p.version-warning {
+  position: sticky;
+  top: 10px;
+
+  margin: 10px 0;
+  padding: 5px 10px;
+  border-radius: 4px;
+
+  letter-spacing: 1px;
+  color: #fff;
+  text-shadow: 0 0 2px #000;
+  text-align: center;
+
+  background: #900
+    repeating-linear-gradient(
+      135deg,
+      transparent,
+      transparent 56px,
+      rgba(255, 255, 255, 0.35) 56px,
+      rgba(255, 255, 255, 0.35) 112px
+    );
+}
+
+p.version-warning a {
+  color: #fff;
+  text-decoration: none;
+  border-bottom: 1px dotted #fff;
+}
+
+p.version-warning a:hover {
+  border-bottom-style: solid;
+}
+/* -------------------------- */