feat: 字体大小16px替换全局变量

src/components/FormCard/styles/index.scss

@@ -48,7 +48,7 @@ $form-transition: all 0.2s ease;
 
 .form-title {
   margin-left: 8px;
-  font-size: 16px;
+  font-size: $uni-font-size-lg;
   font-weight: 500;
   color: $form-primary-color;
   flex: 1;

src/components/OrderCardItem/styles/index.scss

@@ -24,7 +24,7 @@
 }
 
 .order-title {
-  font-size: 16px;
+  font-size: $uni-font-size-lg;
   color: $uni-text-color;
 }
 

src/components/Stepper/styles/index.scss

@@ -5,7 +5,7 @@
 
 .stepper-text {
   width: 40px;
-  font-size: 16px;
+  font-size: $uni-font-size-lg;
   color: $uni-text-color;
   text-align: center;
 }