diff --git a/source/_assets/base_style.scss b/source/_assets/base_style.scss
index 260a194..a44492e 100644
--- a/source/_assets/base_style.scss
+++ b/source/_assets/base_style.scss
@@ -36,6 +36,6 @@ a:active {
 .hr-line {
     height: 0;
     display: block;
-    border-bottom: 1px solid #eee;
+    border-bottom: 1px solid $rule-color;
     margin: 2em 0;
 }
diff --git a/source/_assets/layout_internal/content-tags.scss b/source/_assets/layout_internal/content-tags.scss
index 5150b55..a48e813 100644
--- a/source/_assets/layout_internal/content-tags.scss
+++ b/source/_assets/layout_internal/content-tags.scss
@@ -31,3 +31,13 @@ code {
 img {
     max-width: 100%;
 }
+
+hr {
+    color: $rule-color;
+    border-top: 1px solid $rule-color;
+    border-left: none;
+    border-right: none;
+    border-bottom: none;
+    margin-block-start: 1em;
+    margin-block-end: 1em;
+}
diff --git a/source/_assets/layout_internal/navigation.scss b/source/_assets/layout_internal/navigation.scss
index 9dcad97..ffaa35d 100644
--- a/source/_assets/layout_internal/navigation.scss
+++ b/source/_assets/layout_internal/navigation.scss
@@ -1,6 +1,8 @@
+@import '../vars';
+
 .navigation {
     display: block;
-    border-bottom: 1px solid #eee;
+    border-bottom: 1px solid $rule-color;
     margin-bottom: 1em;
 
     &__actions {
diff --git a/source/_assets/predictor/demo.vue b/source/_assets/predictor/demo.vue
index 19aac19..1d964f4 100644
--- a/source/_assets/predictor/demo.vue
+++ b/source/_assets/predictor/demo.vue
@@ -99,6 +99,7 @@ export default {
 </script>
 
 <style lang="scss" scoped>
+@import '../vars';
 @import '../components/button';
 
 .app {
@@ -117,7 +118,7 @@ export default {
     }
 
     &:hover {
-        border-color: #ccc;
+        border-color: $rule-color;
     }
 }
 
diff --git a/source/_assets/vars.scss b/source/_assets/vars.scss
index 4480753..17a6f92 100644
--- a/source/_assets/vars.scss
+++ b/source/_assets/vars.scss
@@ -14,3 +14,5 @@ $preferred-width: 740px;
 $first-media-step: $preferred-width - 1px;
 
 $mobile-margin: 0.8em;
+
+$rule-color: #e6e6e6;