diff --git a/src/web/public/styles.css b/src/web/public/styles.css
index 0bee818a..c756f2af 100644
--- a/src/web/public/styles.css
+++ b/src/web/public/styles.css
@@ -19413,6 +19413,13 @@ html[data-session-list="sidebar"][data-sidebar="collapsed"] .btn-sidebar-toggle
   height: 100%;
 }
 
+/* As .terminal-container's: xterm paints its viewport black, and the rows
+   rarely fill the tile exactly, so without this every tile had a black band
+   under its last row instead of the terminal background. */
+.tile-body .xterm-viewport {
+  background: transparent !important;
+}
+
 /* Quiet "loading" state while the tile's capture waits in the grid's one load
    queue (or runs). */
 .tile.tile--loading .tile-body::after {