Radio & Checkbox: fix first button style (#10544)

packages/theme-chalk/src/checkbox.scss

@@ -298,6 +298,9 @@
       border-color: $--checkbox-button-checked-border-color;
       box-shadow: -1px 0 0 0 $--color-primary-light-4;
     }
+    &:first-child .el-checkbox-button__inner {
+      border-left-color: $--checkbox-button-checked-border-color;
+    }
   }
 
   &.is-disabled {
@@ -309,6 +312,9 @@
       border-color: $--button-disabled-border;
       box-shadow: none;
     }
+    &:first-child .el-checkbox-button__inner {
+      border-left-color: $--button-disabled-border;
+    }
   }
 
   &:first-child {

packages/theme-chalk/src/radio-button.scss

@@ -41,6 +41,14 @@
     }
   }
 
+  &:first-child {
+    .el-radio-button__inner {
+      border-left: $--border-base;
+      border-radius: $--border-radius-base 0 0 $--border-radius-base;
+      box-shadow: none !important;
+    }
+  }
+
   @include e(orig-radio) {
     opacity: 0;
     outline: none;
@@ -72,13 +80,6 @@
     }
   }
 
-  &:first-child {
-    .el-radio-button__inner {
-      border-left: $--border-base;
-      border-radius: $--border-radius-base 0 0 $--border-radius-base;
-      box-shadow: none !important;
-    }
-  }
   &:last-child {
     .el-radio-button__inner {
       border-radius: 0 $--border-radius-base $--border-radius-base 0;