优化显示：组件上下间隔，footer 位置置于页面底部

src/scss/_element-ui-overwrite.scss

@@ -0,0 +1,49 @@
+$color-checkbox: $blue;
+$color-border-el: #DCDFE6;
+
+$btn-radius: 6px;
+
+/* FORM */
+// checkbox
+.el-checkbox.is-bordered{
+  @include border-radius($btn-radius) ;
+  &:hover{
+    border-color: $color-checkbox;
+    .el-checkbox__label{
+      color: $color-checkbox;
+    }
+  }
+  .el-checkbox__input.is-focus{
+    .el-checkbox__inner{
+      border-color: $color-border-el;
+    }
+  }
+  &.is-checked{
+    background-color: $color-checkbox;
+    .el-checkbox__label{
+      color: white;
+    }
+    .el-checkbox__inner{
+      border-color: white;
+      background-color: white;
+      &:after{
+        border-color: $color-checkbox;
+      }
+    }
+  }
+}
+
+// el-button
+.el-button{
+  @include border-radius($btn-radius) ;
+}
+
+// upload
+.el-upload-dragger{
+  &:hover{
+    background-color: transparentize($color-checkbox, 0.9);
+  }
+}
+.el-upload__tip{
+  color: $text-comment;
+}