diff --git a/themes/_base.sass b/themes/_base.sass
new file mode 100644
index 0000000..23886dd
--- /dev/null
+++ b/themes/_base.sass
@@ -0,0 +1,56 @@
+body
+  margin: $gap-l auto
+  max-width: 700px
+  background: $color-bg
+  color: $color-text
+  padding-inline: $gap-m
+  font-family: $font-main
+  font-weight: 500
+  box-sizing: border-box
+  &::selection
+    color: $color-bg
+    background: $color-selection
+
+
+h1, h2, h3
+  font-family: $font-main,
+  margin-top: $gap-l
+  line-height: 1.2
+
+img
+  display: block
+  width: 100%
+  object-fit: cover
+  object-position: center
+
+a
+  color: $color-link
+  &:hover
+    text-decoration: none
+
+pre
+  font-family: $font-monospace
+
+.isa_info, .isa_success, .isa_warning, .isa_error
+  width: 90%
+  margin: 10px 0px
+  padding: 12px
+
+.isa_info
+  color: #00529b
+  background-color: #bde5f8
+
+.isa_success
+  color: #4f8a10
+  background-color: #dff2bf
+
+.isa_warning
+  color: #9f6000
+  background-color: #feefb3
+
+.isa_error
+  color: #d8000c
+  background-color: #ffd2d2
+
+.timestamp
+  color: $color-text--light
diff --git a/themes/dark.sass b/themes/dark.sass
new file mode 100644
index 0000000..33f8531
--- /dev/null
+++ b/themes/dark.sass
@@ -0,0 +1,11 @@
+$font-main: "Lora", sans-serif
+$font-monospace: "Inconsolata", monospace
+$color-bg: #191919
+$color-text: #ffffffcf
+$color-text--light: lighten($color-text, 20%)
+$color-link: #6FB0E2
+$color-selection: #9BA6B0
+$gap-l: 2.5rem
+$gap-m: 1rem
+
+@use "base"
diff --git a/themes/light.sass b/themes/light.sass
index f10d92f..103af30 100644
--- a/themes/light.sass
+++ b/themes/light.sass
@@ -8,59 +8,4 @@ $color-selection: #4D5460
 $gap-l: 2.5rem
 $gap-m: 1rem
 
-body
-  margin: $gap-l auto
-  max-width: 700px
-  background: $color-bg
-  color: $color-text
-  padding-inline: $gap-m
-  font-family: $font-main
-  font-weight: 500
-  box-sizing: border-box
-  &::selection
-    color: $color-bg
-    background: $color-selection
-
-
-h1, h2, h3
-  font-family: $font-main,
-  margin-top: $gap-l
-  line-height: 1.2
-
-img
-  display: block
-  width: 100%
-  object-fit: cover
-  object-position: center
-
-a
-  color: $color-link
-  &:hover
-    text-decoration: none
-
-pre
-  font-family: $font-monospace
-
-.isa_info, .isa_success, .isa_warning, .isa_error
-  width: 90%
-  margin: 10px 0px
-  padding: 12px
-
-.isa_info
-  color: #00529b
-  background-color: #bde5f8
-
-.isa_success
-  color: #4f8a10
-  background-color: #dff2bf
-
-.isa_warning
-  color: #9f6000
-  background-color: #feefb3
-
-.isa_error
-  color: #d8000c
-  background-color: #ffd2d2
-
-.timestamp
-  color: $color-text--light
+@use "base"