重写将文件预览；本地引入font-awesome字体；

public/cdn/fontawesome-free-6.4.0-web/less/_stacked.less

@@ -0,0 +1,31 @@
+// stacking icons
+// -------------------------
+
+.@{fa-css-prefix}-stack {
+  display: inline-block;
+  height: 2em;
+  line-height: 2em;
+  position: relative;
+  vertical-align: @fa-stack-vertical-align;
+  width: @fa-stack-width;
+}
+
+.@{fa-css-prefix}-stack-1x, .@{fa-css-prefix}-stack-2x {
+  left: 0;
+  position: absolute;
+  text-align: center;
+  width: 100%;
+  z-index: ~'var(--@{fa-css-prefix}-stack-z-index, @{fa-stack-z-index})';
+}
+
+.@{fa-css-prefix}-stack-1x { 
+  line-height: inherit; 
+}
+
+.@{fa-css-prefix}-stack-2x { 
+  font-size: 2em; 
+}
+
+.@{fa-css-prefix}-inverse { 
+  color: ~'var(--@{fa-css-prefix}-inverse, @{fa-inverse})';
+}