diff --git a/src/css/base/spacing.css b/src/css/base/spacing.css
deleted file mode 100644
index 1e402a7..0000000
--- a/src/css/base/spacing.css
+++ /dev/null
@@ -1,19 +0,0 @@
-:root {
-    --space-unit:  1rem;
-  }
-
-:root,
-* {
-	--space-xxxxs: calc(0.125 * var(--space-unit));
-	--space-xxxs:  calc(0.25 * var(--space-unit));
-	--space-xxs:   calc(0.375 * var(--space-unit));
-	--space-xs:    calc(0.5 * var(--space-unit));
-	--space-sm:    calc(0.75 * var(--space-unit));
-	--space-md:    calc(1.25 * var(--space-unit));
-	--space-lg:    calc(2 * var(--space-unit));
-	--space-xl:    calc(3.25 * var(--space-unit));
-	--space-xxl:   calc(5.25 * var(--space-unit));
-	--space-xxxl:  calc(8.5 * var(--space-unit));
-	--space-xxxxl: calc(13.75 * var(--space-unit));
-	--component-padding: var(--space-md);
-}
diff --git a/src/css/base/colors.css b/src/css/colors.css
similarity index 100%
rename from src/css/base/colors.css
rename to src/css/colors.css
diff --git a/src/css/base/reset.css b/src/css/reset.css
similarity index 100%
rename from src/css/base/reset.css
rename to src/css/reset.css
diff --git a/src/css/base/variables.css b/src/css/variables.css
similarity index 72%
rename from src/css/base/variables.css
rename to src/css/variables.css
index 986a8f6..f7968d7 100644
--- a/src/css/base/variables.css
+++ b/src/css/variables.css
@@ -5,6 +5,9 @@
 	--zindex-fixed-element: 10;          /* e.g., 'back to top' button */
 	--zindex-overlay: 15;                /* e.g., modals and dialogs */
 
+	/* space unit */
+	--space-unit:  1rem;
+
 	/*radius */
 	--radius-sm: calc(var(--radius, 0.25em) / 2);
 	--radius-md: var(--radius, 0.25em);
@@ -37,3 +40,19 @@
 	--ease-out: cubic-bezier(0.215, 0.61, 0.355, 1);
 	--ease-out-back: cubic-bezier(0.34, 1.56, 0.64, 1);
 }
+
+:root,
+* {
+	--space-xxxxs: calc(0.125 * var(--space-unit));
+	--space-xxxs:  calc(0.25 * var(--space-unit));
+	--space-xxs:   calc(0.375 * var(--space-unit));
+	--space-xs:    calc(0.5 * var(--space-unit));
+	--space-sm:    calc(0.75 * var(--space-unit));
+	--space-md:    calc(1.25 * var(--space-unit));
+	--space-lg:    calc(2 * var(--space-unit));
+	--space-xl:    calc(3.25 * var(--space-unit));
+	--space-xxl:   calc(5.25 * var(--space-unit));
+	--space-xxxl:  calc(8.5 * var(--space-unit));
+	--space-xxxxl: calc(13.75 * var(--space-unit));
+	--component-padding: var(--space-md);
+}