add: add variables.scss

src/styles/btn.scss

-$blue:#324157;
-$light-blue:#3A71A8;
-$red:#C03639;
-$pink: #E65D6E;
-$green: #30B08F;
-$tiffany: #4AB7BD;
-$yellow:#FEC171;
-$panGreen: #30B08F;
+@import './variables.scss';
 
 @mixin colorBtn($color) {
   background: $color;

src/styles/variables.scss

+$blue:#324157;
+$light-blue:#3A71A8;
+$red:#C03639;
+$pink: #E65D6E;
+$green: #30B08F;
+$tiffany: #4AB7BD;
+$yellow:#FEC171;
+$panGreen: #30B08F;