refactor(app.css): rename colors to variables

* Add max-width css variable

Author: sarmstead

src/css/app.css

@@ -1,6 +1,6 @@
 /* Base */
 @import './base/typography.css';
-@import './base/colors.css';
+@import './base/variables.css';
 
 /* Components */
 @import './components/button.css';

src/css/base/colors.css src/css/base/variables.csssrc/css/base/colors.css renamed to src/css/base/variables.css

@@ -1,4 +1,5 @@
 :root {
+    /* Colors */
     --red: #e14943;
     --darkred: #cf2821;
     --purple: #755384;
@@ -11,4 +12,7 @@
     --navy: #292e37;
     --mutednavy: #444d5c;
     --divider: #f6f3f0;
+
+    /* Layout */
+    --layout-inner-max-width: 1135px;
 }