diff --git a/docs/src/basics/configuration.djot b/docs/src/basics/configuration.djot
index d0960c0..ee61da6 100644
--- a/docs/src/basics/configuration.djot
+++ b/docs/src/basics/configuration.djot
@@ -3,6 +3,11 @@ order: -1
 ---
 # Configuration reference
 
+{.tag-aside .warning}
+:::
+Djockey is pre-alpha and config options _will_ change.
+:::
+
 ```yaml
 # djockey.yaml
 siteName: "Your name here"
diff --git a/templates/html/static/dj-asides.css b/templates/html/static/dj-asides.css
new file mode 100644
index 0000000..ae96994
--- /dev/null
+++ b/templates/html/static/dj-asides.css
@@ -0,0 +1,31 @@
+aside {
+  border-width: var(--aside-border-width);
+  border-radius: var(--aside-border-radius);
+  border-style: solid;
+  overflow: hidden;
+}
+
+aside > * {
+  margin: 0 var(--ms);
+}
+
+aside > *:last-child {
+  margin-bottom: var(--ms);
+}
+
+aside::before {
+  font-weight: var(--fw-bold);
+  margin: 0 0 var(--ms) 0;
+  padding: var(--mss) var(--ms);
+  display: block;
+  background-color: var(--aside-title-color-bg-warning);
+}
+
+aside.warning::before {
+  content: "Warning";
+}
+
+aside.warning {
+  border-color: var(--aside-color-border-warning);
+  font-size: var(--fs-small);
+}
diff --git a/templates/html/static/dj-typography.css b/templates/html/static/dj-typography.css
index 3b15bc2..d8ecb08 100644
--- a/templates/html/static/dj-typography.css
+++ b/templates/html/static/dj-typography.css
@@ -21,6 +21,7 @@ header h1 {
 
 article p,
 article pre,
+article aside,
 article ol,
 article ul {
   margin-bottom: 1.25em;
diff --git a/templates/html/static/dj-variables.css b/templates/html/static/dj-variables.css
index 278c8da..7e2b4ef 100644
--- a/templates/html/static/dj-variables.css
+++ b/templates/html/static/dj-variables.css
@@ -1,6 +1,8 @@
 :root {
   /* PALETTE */
 
+  /* It's OK to define one-off colors, but consider promoting them to palette colors ASAP. */
+
   /*
   Prefixes:
   -f: fonts
@@ -82,6 +84,13 @@
   --approx-height-of-top-bar-during-scroll: calc(
     var(--header-height) + var(--mm)
   );
+
+  /* COMPONENT VALUES */
+
+  --aside-border-width: 1px;
+  --aside-border-radius: 4px;
+  --aside-color-border-warning: red;
+  --aside-title-color-bg-warning: rgb(251, 205, 205);
 }
 
 @media (prefers-color-scheme: dark) {