Fix ghost button background to transparent, close #1126

style/mixins/button.less

@@ -153,11 +153,11 @@
 
   &:hover,
   &:focus {
-    .button-color(tint(@primary-color, 20%); white; tint(@primary-color, 20%));
+    .button-color(tint(@primary-color, 20%); @btn-ghost-bg; tint(@primary-color, 20%));
   }
   &:active,
   &.active {
-    .button-color(shade(@primary-color, 5%); white; shade(@primary-color, 5%));
+    .button-color(shade(@primary-color, 5%); @btn-ghost-bg; shade(@primary-color, 5%));
   }
 }
 
@@ -168,11 +168,11 @@
 
   &:hover,
   &:focus {
-    .button-color(tint(@primary-color, 20%); white; tint(@primary-color, 20%));
+    .button-color(tint(@primary-color, 20%); @btn-ghost-bg; tint(@primary-color, 20%));
   }
   &:active,
   &.active {
-    .button-color(shade(@primary-color, 5%); white; shade(@primary-color, 5%));
+    .button-color(shade(@primary-color, 5%); @btn-ghost-bg; shade(@primary-color, 5%));
   }
 }
 

style/themes/default/custom.less

@@ -63,7 +63,7 @@
 @btn-default-border     : @border-color-base;
 
 @btn-ghost-color        : @text-color;
-@btn-ghost-bg           : #fff;
+@btn-ghost-bg           : transparent;
 @btn-ghost-border       : @border-color-base;
 
 @btn-disable-color      : #ccc;