Add @steps-background and @process-icon-text-color variables for customizing step theme

components/steps/style/index.less

@@ -6,6 +6,7 @@
 @process-title-color: @text-color;
 @process-description-color: @process-title-color;
 @process-tail-color: @border-color-split;
+@process-icon-text-color: #fff;
 @wait-icon-color: @disabled-color;
 @wait-title-color: @text-color-secondary;
 @wait-description-color: @wait-title-color;
@@ -18,6 +19,7 @@
 @error-title-color: @error-color;
 @error-description-color: @error-color;
 @error-tail-color: @error-color;
+@steps-background: @component-background;
 
 @steps-icon-size: 26px;
 @steps-small-icon-size: 18px;
@@ -37,7 +39,7 @@
     &.@{steps-prefix-cls}-status-wait {
       .@{steps-prefix-cls}-head-inner {
         border-color: @wait-icon-color;
-        background-color: @component-background;
+        background-color: @steps-background;
         > .@{steps-prefix-cls}-icon {
           color: @wait-icon-color;
           .@{steps-prefix-cls}-icon-dot {
@@ -60,7 +62,7 @@
         border-color: @process-icon-color;
         background-color: @process-icon-color;
         > .@{steps-prefix-cls}-icon {
-          color: @component-background;
+          color: @process-icon-text-color;
           .@{steps-prefix-cls}-icon-dot {
             background: @process-icon-color;
           }
@@ -79,7 +81,7 @@
     &.@{steps-prefix-cls}-status-finish {
       .@{steps-prefix-cls}-head-inner {
         border-color: @finish-icon-color;
-        background-color: @component-background;
+        background-color: @steps-background;
         > .@{steps-prefix-cls}-icon {
           color: @finish-icon-color;
           .@{steps-prefix-cls}-icon-dot {
@@ -106,7 +108,7 @@
     &.@{steps-prefix-cls}-status-error {
       .@{steps-prefix-cls}-head-inner {
         border-color: @error-icon-color;
-        background-color: @component-background;
+        background-color: @steps-background;
         > .@{steps-prefix-cls}-icon {
           color: @error-icon-color;
           .@{steps-prefix-cls}-icon-dot {
@@ -159,7 +161,7 @@
     vertical-align: top;
   }
   .@{steps-prefix-cls}-head {
-    background: @component-background;
+    background: @steps-background;
   }
 
   .@{steps-prefix-cls}-head-inner {
@@ -195,7 +197,7 @@
     margin-bottom: 4px;
     color: @text-color;
     font-weight: bold;
-    background: @component-background;
+    background-color: @steps-background;
     display: inline-block;
     padding-right: 10px;
     > a:first-child:last-child {