diff --git a/static-html/postcss b/static-html/postcss
index 42607e3..1133e71 160000
--- a/static-html/postcss
+++ b/static-html/postcss
@@ -1 +1 @@
-Subproject commit 42607e30c86755da9a2d17789f89a4128ee4e2e6
+Subproject commit 1133e71b1627bdc7ac64653458988a0713f6cdb0
diff --git a/static-html/postcss.config.js b/static-html/postcss.config.js
index 922ffb5..ae8599b 100644
--- a/static-html/postcss.config.js
+++ b/static-html/postcss.config.js
@@ -1,16 +1,13 @@
-const postcssFunctions = require('./src/js/postcss-functions');
+const postcssFunctions = require('./postcss/functions');
+const postcssMixins = require('./postcss/mixins');
 
 module.exports = {
   plugins: [
     'postcss-import',
-    'postcss-mixins',
+    ['postcss-mixins', { mixins: postcssMixins }],
     'postcss-preset-env',
     'postcss-nesting',
     'postcss-simple-vars',
-    ['postcss-functions',
-      {
-        functions: postcssFunctions,
-      },
-    ],
+    ['postcss-functions', { functions: postcssFunctions }],
   ],
 };
diff --git a/static-html/src/css/style.css b/static-html/src/css/style.css
index c16a853..f4a5708 100644
--- a/static-html/src/css/style.css
+++ b/static-html/src/css/style.css
@@ -4,7 +4,9 @@
 	$color: green;
 	color: $color;
 
-	opacity: half(1);
+	@mixin defineColor --color-text, #f00;
+
+	color: toHSLA(--color-text, 0.5);
 
 	@mixin size-big 2em;
 
diff --git a/static-html/src/js/postcss-functions.js b/static-html/src/js/postcss-functions.js
deleted file mode 100644
index ce521ed..0000000
--- a/static-html/src/js/postcss-functions.js
+++ /dev/null
@@ -1,7 +0,0 @@
-const postcssFunctions = {
-  half(val) {
-    return val / 2;
-  },
-};
-
-module.exports = postcssFunctions;