update the style of button page

components/button/demo/button-group.md

@@ -32,12 +32,12 @@
 <h4>带图标按钮组合 </h4>
 <div class="ant-btn-group">
   <button class="ant-btn ant-btn-primary">
-  <span class="anticon anticon-double-left"></span>
+  <span class="anticon anticon-left"></span>
   <span>后 退</span>
   </button>
   <button class="ant-btn ant-btn-primary">
   <span>前 进</span>
-  <span class="anticon anticon-double-right"></span>
+  <span class="anticon anticon-right"></span>
   </button>
 </div>
 <div class="ant-btn-group">
@@ -56,7 +56,7 @@
   <button class="ant-btn ant-btn-ghost">4</button>
   <button class="ant-btn ant-btn-ghost">
   <span>前 进</span>
-  <span class="anticon anticon-double-right"></span>
+  <span class="anticon anticon-right"></span>
   </button>
 </div>
 <h4>尺寸</h4>
@@ -78,13 +78,18 @@
 ````
 
 <style>
+.nico-insert-code h4 {
+  font-size: 12px;
+  font-weight: 500;
+}
 .nico-insert-code h4:first-child {
   margin-top: 0;
 }
 .nico-insert-code .ant-btn-group {
+  margin-top: 16px;
   margin-left: 8px;
 }
 .nico-insert-code .ant-btn {
-  margin-bottom: 10px;
+  margin-bottom: 8px;
 }
 </style>

style/mixins/button.less

@@ -88,11 +88,12 @@
   line-height: @line-height-base;
   .button-size(@btn-padding-base; @font-size-base; @btn-border-radius-base);
   .user-select(none);
-  .transition(all .4s @ease-in-out);
+  .transition(all .3s @ease-in-out);
   -webkit-transform: translate3d(0, 0, 0);
 
   > .@{iconfont-css-prefix} {
     font-size: @font-size-base + 2;
+    line-height: 1;
     z-index: 2;
   }
 
@@ -108,6 +109,7 @@
 
   &:not([disabled]):active {
     outline: 0;
+    .transition(none);
   }
 
   &.disabled,