Drop the outer leaderboard border entirely

* .vbench-wrap loses its border, border-radius, and shadow — there is
no visible card outline around the leaderboard anymore. The inner
.vbench-scroll still handles overflow.
* gr.HTML for the leaderboard is now created with container=False so
Gradio's own card box around the HTML component is also dropped.
Together this means the table sits flush on the tab background
without any wrapping outline.

app.py

@@ -102,18 +102,10 @@ LEADERBOARD_CSS = """
 /* Palette: Stripe-inspired (navy #0a2540 / slate text #425466 / pale #f6f9fc).
    TextScore column = deep navy primary; the three text-correctness primitives
    that feed it carry a soft tint; remaining detail metrics are quiet slate. */
-/* Two-tier wrap so the 12px border-radius clips the rounded corners
-   regardless of how the inner table scrolls. The outer card holds the
-   border + radius + shadow with overflow:hidden; the inner element is
-   the actual scroll container. */
-.vbench-wrap {
-    width: 100%;
-    border: 1px solid #e3e8ee;
-    border-radius: 12px;
-    overflow: hidden;
-    box-shadow: 0 1px 2px rgba(10, 37, 64, 0.04);
-    background: #fff;
-}
+/* Borderless wrap. The outer .vbench-wrap is now a transparent
+   pass-through with no border, radius, or shadow; the inner
+   .vbench-scroll handles the actual scrolling. */
+.vbench-wrap   { width: 100%; background: transparent; }
 .vbench-scroll {
     width: 100%;
     overflow-x: auto;
@@ -752,7 +744,8 @@ with gr.Blocks(title="ViTeX-Bench Leaderboard",
     gr.Markdown(HEADER_MD)
 
     with gr.Tab("📊 Leaderboard"):
-        leaderboard_html = gr.HTML(value=render_leaderboard_html())
+        leaderboard_html = gr.HTML(value=render_leaderboard_html(),
+                                   container=False)
         refresh_btn = gr.Button("🔄 Refresh", variant="primary", size="sm")
         refresh_btn.click(fn=render_leaderboard_html, outputs=leaderboard_html)