style: 优化 font-family, 让页面字体更清晰均匀 (#2924)

src/css/layui.css

@@ -89,12 +89,8 @@ body {
   color: rgba(0, 0, 0, 0.85);
   font-size: 14px;
   font-family:
-    Helvetica Neue,
-    Helvetica,
-    PingFang SC,
-    Tahoma,
-    Arial,
-    sans-serif;
+    -apple-system, BlinkMacSystemFont, system-ui, "Segoe UI", "PingFang SC",
+    "Helvetica Neue", Helvetica, Arial, sans-serif;
 }
 hr {
   height: 0;
@@ -2194,7 +2190,7 @@ hr.layui-border-black {
   display: inline-block;
   vertical-align: middle;
   height: 38px;
-  line-height: 38px;
+  line-height: 36px;
   border: 1px solid transparent;
   padding: 0 18px;
   background-color: #16baaa;
@@ -2288,21 +2284,21 @@ hr.layui-border-black {
 /* 大型 */
 .layui-btn-lg {
   height: 44px;
-  line-height: 44px;
+  line-height: 42px;
   padding: 0 25px;
   font-size: 16px;
 }
 /* 小型 */
 .layui-btn-sm {
   height: 30px;
-  line-height: 30px;
+  line-height: 28px;
   padding: 0 10px;
   font-size: 12px;
 }
 /* 超小 */
 .layui-btn-xs {
   height: 22px;
-  line-height: 22px;
+  line-height: 20px;
   padding: 0 5px;
   font-size: 12px;
 }