docs: update CrossFlicking demo

Author: malangfox

docs/src/css/demo/crossflicking.css

@@ -23,7 +23,8 @@
 .img {
   width: 100%;
   height: 100%;
-  opacity: 0.5;
+  opacity: 0.6;
+  object-fit: none;
 }
 
 .labels {
@@ -77,7 +78,7 @@
   -webkit-box-align: center;
   -webkit-align-items: center;
   align-items: center;
-  line-height: 24px;
+  line-height: 42px;
   font-size: 30px;
   color: rgba(255, 255, 255, 0.6);
 }
@@ -97,7 +98,7 @@
 
 .area {
   position: absolute;
-  width: 92px;
+  width: 85px;
   height: 40px;
   -webkit-border-radius: 100px;
   border-radius: 100px;