diff --git a/page/api.ts b/page/api.ts
index 2fab75c..123e54d 100644
--- a/page/api.ts
+++ b/page/api.ts
@@ -262,7 +262,7 @@ hoverables.addEventListener('wheel', e => {
   fcitx._page((<WheelEvent>e).deltaY > 0)
 })
 
-const distribution = process.env.FCITX_DISTRIBUTION
+const distribution = <string>process.env.FCITX_DISTRIBUTION ?? ''
 
 let fcitx: FCITX
 
@@ -292,6 +292,8 @@ if (distribution === 'fcitx5-js') {
   document.head.append(style)
 }
 
+fcitx.distribution = distribution
+
 // JavaScript APIs that webview_candidate_window.cpp calls
 fcitx.setCandidates = setCandidates
 fcitx.setLayout = setLayout
diff --git a/page/global.d.ts b/page/global.d.ts
index 5853b51..2b9e6a5 100644
--- a/page/global.d.ts
+++ b/page/global.d.ts
@@ -22,6 +22,8 @@ declare global {
   }
 
   type FCITX = {
+    distribution: string
+
     // C++ APIs that api.ts calls
     _onload?: () => void
     _log: (s: string) => void
diff --git a/page/ux.ts b/page/ux.ts
index ff47549..f023b6d 100644
--- a/page/ux.ts
+++ b/page/ux.ts
@@ -184,11 +184,16 @@ decoration.addEventListener('mousemove', e => {
   dragging = true
   const dx = e.clientX - startX
   const dy = e.clientY - startY
+  if (window.fcitx.distribution === 'fcitx5-js') {
+    // On desktop mouse is always at where drag starts in the html,
+    // but on f5j mouse can be anywhere during drag.
+    startX = e.clientX
+    startY = e.clientY
+  }
   dX += dx
   dY += dy
   dragOffset = Math.max(dragOffset, dX * dX + dY * dY)
-  // minus because macOS has bottom-left (0, 0)
-  resize(dx, -dy, true, false)
+  resize(dx, dy, true, false)
 })
 
 decoration.addEventListener('mouseup', e => {
diff --git a/src/platform/js.cpp b/src/platform/js.cpp
index 6e66e94..3dec931 100644
--- a/src/platform/js.cpp
+++ b/src/platform/js.cpp
@@ -18,7 +18,7 @@ void WebviewCandidateWindow::set_transparent_background() {}
 
 void WebviewCandidateWindow::update_accent_color() {}
 
-void WebviewCandidateWindow::hide() { std::cerr << "hide" << std::endl; }
+void WebviewCandidateWindow::hide() { EM_ASM(fcitx.hidePanel()); }
 
 void WebviewCandidateWindow::write_clipboard(const std::string &html) {}
 
diff --git a/src/platform/macos.mm b/src/platform/macos.mm
index f1db7ed..c3979c3 100644
--- a/src/platform/macos.mm
+++ b/src/platform/macos.mm
@@ -200,7 +200,7 @@ NSRect getNearestScreenFrame(double x, double y) {
 
     if (dragging) {
         x_ += dx;
-        y_ += dy;
+        y_ -= dy; // minus because macOS has bottom-left (0, 0)
     } else {
         if (layout_ == layout_t::vertical &&
             writing_mode_ == writing_mode_t::vertical_rl) {