perf(styles): 优化图标按钮全局样式

src/styles/global.scss

@@ -69,11 +69,12 @@
 }
 
 .icon-button {
-  display: inline-flex;
-  align-items: center;
-  justify-content: center;
   font-size: 16px;
 
+  i {
+    vertical-align: -0.15em;
+  }
+
   span {
     margin-left: 8px;
   }