refactor(HomePage): 重构排行榜按钮布局样式

将.span-4的样式重构为flex布局，并添加.span-4-1作为按钮容器
保持原有功能不变，提升布局灵活性和可维护性

src/pages/HomePage/HomePage.less

@@ -363,10 +363,16 @@
              width: 25%;
            }
           .span-4{
-            width: 136px;
-            height: 47px;
-             width: 25%;
-            .sparkBg("homePage/top-btn2.png");
+            width: 25%;
+            display: flex;
+            align-items: center;
+            justify-content: center;
+            .span-4-1{
+               width: 136px;
+               height: 47px;
+               .sparkBg("homePage/top-btn2.png");
+            }
+           
            }
         }
       }
@@ -396,10 +402,15 @@
           width: 25%;
         }
         .span-4{
-           width: 136px;
-           height: 47px;
            width: 25%;
-           .sparkBg("homePage/top-btn2.png");
+           display: flex;
+           align-items: center;
+           justify-content: center;
+           .span-4-1{
+             width: 136px;
+             height: 47px;
+             .sparkBg("homePage/top-btn2.png");
+           }
         }
       }
     }

src/pages/HomePage/HomePage.tsx

@@ -220,7 +220,9 @@ class HomePage extends React.Component<any, any> {
                       <span className='span-1'>{item.index}</span>
                       <span className='span-2'>{item.userName}</span>
                       <span className='span-3'>{item.score > 0 ? `+${item.score}` : item.score}%</span>
-                      <span className='span-4' onClick={() => this.viewDistribution(item)}></span>
+                      <span className='span-4' onClick={() => this.viewDistribution(item)}>
+                        <span className='span-4-1'></span>
+                      </span>
                     </div>
                   ))
                 }
@@ -230,7 +232,9 @@ class HomePage extends React.Component<any, any> {
                 <span className='span-1'>{myRank.index == null ? '未上榜' : myRank.index >= 100 ? '99+' : myRank.index}</span>
                 <span className='span-2'>{myRank.userName}（我）</span>
                 <span className='span-3'>{myRank && myRank.score != null ? (myRank.score > 0 ? `+${myRank.score}` : myRank.score) : '-'}%</span>
-                <span className='span-4' onClick={() => this.viewDistribution(myRank)}></span>
+                <span className='span-4' onClick={() => this.viewDistribution(myRank)}>
+                   <span className='span-4-1'></span>
+                </span>
               </div>
               {/* 展开 */}
               <div className='postRanking_expand'>