front: center resize handle

Signed-off-by: nncluzu <[email protected]>

Author: kmer2016

front/src/styles/scss/common/components/_resizableSection.scss

@@ -5,13 +5,14 @@
     display: flex;
     justify-content: center;
     align-items: center;
+    z-index: 1;
+    transform: translateY(8px); // Move handle down to center it in the 16px gap
 
     &::after {
       content: '';
       width: 72px;
       height: 4px;
       border-radius: 2px;
-      margin-bottom: 6px;
       background-color: var(--coolgray3);
     }
     &:hover::after {