diff --git a/public/css/panel.css b/public/css/panel.css
index c4397e6..a2e2d0a 100644
--- a/public/css/panel.css
+++ b/public/css/panel.css
@@ -291,22 +291,14 @@
   stroke-width: 3px;
 }
 
-/* Mobile: bottom-sheet */
+/* Mobile: full-screen overlay */
 @media (max-width: 768px) {
   #tool-panel {
     width: 100vw;
-    height: 80vh;
-    top: auto;
-    bottom: 0;
+    height: 100vh;
+    top: 0;
     right: 0;
     border-left: none;
-    border-top: 1px solid var(--color-border);
-    border-radius: var(--radius-md) var(--radius-md) 0 0;
-    transform: translateY(100%);
-    transition: transform 250ms ease;
-  }
-
-  #tool-panel.open {
-    transform: translateY(0);
+    border-radius: 0;
   }
 }