feat: implement 6 research-backed mobile responsive features

- Bottom sheet for mobile tool settings (replaces top-collapsible panel)
- Pinch-to-zoom and wheel zoom on image viewer via @use-gesture/react
- Replace all vh units with dvh for dynamic viewport height
- Vertical before-after comparison on mobile devices
- Konva multi-touch pinch-to-zoom on editor canvas
- Container queries for adaptive tool settings + touch-friendly CSS

apps/web/src/components/common/before-after-slider.tsx

@@ -1,6 +1,8 @@
 import { type PointerEvent, useCallback, useEffect, useRef, useState } from "react";
 import type { BgPreviewState } from "@/components/common/image-viewer";
 import { useTranslation } from "@/contexts/i18n-context";
+import { useMobile } from "@/hooks/use-mobile";
+import { cn } from "@/lib/utils";
 
 interface BeforeAfterSliderProps {
   /** URL or data URL of original image. */
@@ -40,25 +42,35 @@ export function BeforeAfterSlider({
   bgPreview,
 }: BeforeAfterSliderProps) {
   const { t } = useTranslation();
+  const isMobile = useMobile();
   const containerRef = useRef<HTMLDivElement>(null);
   const [position, setPosition] = useState(initialPosition); // percentage 0-100
   const [isDragging, setIsDragging] = useState(false);
 
-  const updatePosition = useCallback((clientX: number) => {
-    const container = containerRef.current;
-    if (!container) return;
-    const rect = container.getBoundingClientRect();
-    const x = clientX - rect.left;
-    const pct = Math.max(0, Math.min(100, (x / rect.width) * 100));
-    setPosition(pct);
-  }, []);
+  const updatePosition = useCallback(
+    (clientX: number, clientY: number) => {
+      const container = containerRef.current;
+      if (!container) return;
+      const rect = container.getBoundingClientRect();
+      if (isMobile) {
+        const y = clientY - rect.top;
+        const pct = Math.max(0, Math.min(100, (y / rect.height) * 100));
+        setPosition(pct);
+      } else {
+        const x = clientX - rect.left;
+        const pct = Math.max(0, Math.min(100, (x / rect.width) * 100));
+        setPosition(pct);
+      }
+    },
+    [isMobile],
+  );
 
   const handlePointerDown = useCallback(
     (e: PointerEvent) => {
       e.preventDefault();
       setIsDragging(true);
       (e.target as HTMLElement).setPointerCapture(e.pointerId);
-      updatePosition(e.clientX);
+      updatePosition(e.clientX, e.clientY);
     },
     [updatePosition],
   );
@@ -66,7 +78,7 @@ export function BeforeAfterSlider({
   const handlePointerMove = useCallback(
     (e: PointerEvent) => {
       if (!isDragging) return;
-      updatePosition(e.clientX);
+      updatePosition(e.clientX, e.clientY);
     },
     [isDragging, updatePosition],
   );
@@ -128,26 +140,36 @@ export function BeforeAfterSlider({
         aria-valuemax={100}
         tabIndex={0}
         className="relative w-full overflow-hidden rounded-lg border border-border select-none touch-none"
-        style={{ cursor: isDragging ? "ew-resize" : "default" }}
+        style={{ cursor: isDragging ? (isMobile ? "ns-resize" : "ew-resize") : "default" }}
         onPointerDown={handlePointerDown}
         onPointerMove={handlePointerMove}
         onPointerUp={handlePointerUp}
         onPointerCancel={handlePointerUp}
         onKeyDown={(e) => {
-          if (e.key === "ArrowLeft") setPosition((p) => Math.max(0, p - 1));
-          else if (e.key === "ArrowRight") setPosition((p) => Math.min(100, p + 1));
+          if (isMobile) {
+            if (e.key === "ArrowUp") setPosition((p) => Math.max(0, p - 1));
+            else if (e.key === "ArrowDown") setPosition((p) => Math.min(100, p + 1));
+          } else {
+            if (e.key === "ArrowLeft") setPosition((p) => Math.max(0, p - 1));
+            else if (e.key === "ArrowRight") setPosition((p) => Math.min(100, p + 1));
+          }
         }}
       >
         {/* Before image (full width, bottom layer) */}
         <img
           src={beforeSrc}
           alt="Original"
-          className="block w-full max-h-[70vh] object-contain"
+          className="block w-full max-h-[70dvh] object-contain"
           draggable={false}
         />
 
         {/* After panel (clipped, top layer) */}
-        <div className="absolute inset-0" style={{ clipPath: `inset(0 0 0 ${position}%)` }}>
+        <div
+          className="absolute inset-0"
+          style={{
+            clipPath: isMobile ? `inset(${position}% 0 0 0)` : `inset(0 0 0 ${position}%)`,
+          }}
+        >
           {/* Background layers constrained to the image content area */}
           {contentBox && (
             <div
@@ -189,43 +211,87 @@ export function BeforeAfterSlider({
         </div>
 
         {/* Divider line */}
-        <div
-          className="absolute top-0 bottom-0 w-0.5 bg-white/80 pointer-events-none"
-          style={{ left: `${position}%`, transform: "translateX(-50%)" }}
-        >
-          {/* Handle grip */}
-          <div className="absolute top-1/2 left-1/2 -translate-x-1/2 -translate-y-1/2 w-8 h-8 rounded-full bg-white border-2 border-primary shadow-lg flex items-center justify-center pointer-events-none">
-            <svg
-              width="14"
-              height="14"
-              viewBox="0 0 14 14"
-              fill="none"
-              className="text-primary"
-              aria-hidden="true"
-            >
-              <path
-                d="M4 3L1 7L4 11"
-                stroke="currentColor"
-                strokeWidth="1.5"
-                strokeLinecap="round"
-                strokeLinejoin="round"
-              />
-              <path
-                d="M10 3L13 7L10 11"
-                stroke="currentColor"
-                strokeWidth="1.5"
-                strokeLinecap="round"
-                strokeLinejoin="round"
-              />
-            </svg>
+        {isMobile ? (
+          <div
+            className="absolute inset-x-0 h-0.5 bg-white/80 pointer-events-none"
+            style={{ top: `${position}%`, transform: "translateY(-50%)" }}
+          >
+            {/* Handle grip */}
+            <div className="absolute top-1/2 left-1/2 -translate-x-1/2 -translate-y-1/2 w-8 h-8 rounded-full bg-white border-2 border-primary shadow-lg flex items-center justify-center pointer-events-none">
+              <svg
+                width="14"
+                height="14"
+                viewBox="0 0 14 14"
+                fill="none"
+                className="text-primary rotate-90"
+                aria-hidden="true"
+              >
+                <path
+                  d="M4 3L1 7L4 11"
+                  stroke="currentColor"
+                  strokeWidth="1.5"
+                  strokeLinecap="round"
+                  strokeLinejoin="round"
+                />
+                <path
+                  d="M10 3L13 7L10 11"
+                  stroke="currentColor"
+                  strokeWidth="1.5"
+                  strokeLinecap="round"
+                  strokeLinejoin="round"
+                />
+              </svg>
+            </div>
           </div>
-        </div>
+        ) : (
+          <div
+            className="absolute top-0 bottom-0 w-0.5 bg-white/80 pointer-events-none"
+            style={{ left: `${position}%`, transform: "translateX(-50%)" }}
+          >
+            {/* Handle grip */}
+            <div className="absolute top-1/2 left-1/2 -translate-x-1/2 -translate-y-1/2 w-8 h-8 rounded-full bg-white border-2 border-primary shadow-lg flex items-center justify-center pointer-events-none">
+              <svg
+                width="14"
+                height="14"
+                viewBox="0 0 14 14"
+                fill="none"
+                className="text-primary"
+                aria-hidden="true"
+              >
+                <path
+                  d="M4 3L1 7L4 11"
+                  stroke="currentColor"
+                  strokeWidth="1.5"
+                  strokeLinecap="round"
+                  strokeLinejoin="round"
+                />
+                <path
+                  d="M10 3L13 7L10 11"
+                  stroke="currentColor"
+                  strokeWidth="1.5"
+                  strokeLinecap="round"
+                  strokeLinejoin="round"
+                />
+              </svg>
+            </div>
+          </div>
+        )}
 
         {/* Labels */}
-        <div className="absolute top-2 left-2 px-2 py-0.5 rounded bg-black/50 text-white text-xs font-medium pointer-events-none">
+        <div
+          className={cn(
+            "absolute px-2 py-0.5 rounded bg-black/50 text-white text-xs font-medium pointer-events-none",
+            isMobile ? "top-2 start-2" : "top-2 left-2",
+          )}
+        >
           {t.comparison.original}
         </div>
-        <div className="absolute top-2 right-2 px-2 py-0.5 rounded bg-black/50 text-white text-xs font-medium pointer-events-none">
+        <div
+          className={cn(
+            "absolute px-2 py-0.5 rounded bg-black/50 text-white text-xs font-medium pointer-events-none",
+            isMobile ? "bottom-2 end-2" : "top-2 right-2",
+          )}
+        >
           {t.comparison.processed}
         </div>
       </div>

apps/web/src/components/common/bottom-sheet.tsx

@@ -0,0 +1,108 @@
+import { useDrag } from "@use-gesture/react";
+import { X } from "lucide-react";
+import { useCallback, useEffect, useRef, useState } from "react";
+
+interface BottomSheetProps {
+  open: boolean;
+  onClose: () => void;
+  title?: string;
+  children: React.ReactNode;
+  maxHeight?: string;
+}
+
+export function BottomSheet({
+  open,
+  onClose,
+  title,
+  children,
+  maxHeight = "70dvh",
+}: BottomSheetProps) {
+  const sheetRef = useRef<HTMLDivElement>(null);
+  const [translateY, setTranslateY] = useState(0);
+
+  // Close on Escape key
+  useEffect(() => {
+    if (!open) return;
+    const handler = (e: KeyboardEvent) => {
+      if (e.key === "Escape") onClose();
+    };
+    window.addEventListener("keydown", handler);
+    return () => window.removeEventListener("keydown", handler);
+  }, [open, onClose]);
+
+  // Reset translation when opened
+  useEffect(() => {
+    if (open) setTranslateY(0);
+  }, [open]);
+
+  const handleDismiss = useCallback(() => {
+    setTranslateY(0);
+    onClose();
+  }, [onClose]);
+
+  const bind = useDrag(
+    ({ movement: [, my], last, cancel }) => {
+      // Only allow downward dragging
+      if (my < 0) {
+        setTranslateY(0);
+        return;
+      }
+      if (last) {
+        if (my > 100) {
+          handleDismiss();
+        } else {
+          setTranslateY(0);
+        }
+        return;
+      }
+      setTranslateY(my);
+    },
+    { axis: "y", filterTaps: true },
+  );
+
+  if (!open) return null;
+
+  return (
+    <>
+      {/* Backdrop */}
+      <div
+        aria-hidden="true"
+        className="fixed inset-0 z-40 bg-black/50 backdrop-blur-sm"
+        onClick={handleDismiss}
+      />
+
+      {/* Sheet */}
+      <div
+        ref={sheetRef}
+        className="fixed inset-x-0 bottom-0 z-50 bg-background border-t border-border rounded-t-2xl shadow-xl flex flex-col animate-in slide-in-from-bottom"
+        style={{
+          maxHeight,
+          transform: translateY > 0 ? `translateY(${translateY}px)` : undefined,
+          transition: translateY > 0 ? "none" : "transform 0.2s ease-out",
+        }}
+      >
+        {/* Drag handle */}
+        <div {...bind()} className="flex justify-center pt-2 pb-1 cursor-grab touch-none">
+          <div className="w-8 h-1 rounded-full bg-muted-foreground/30" />
+        </div>
+
+        {/* Header */}
+        {title && (
+          <div className="flex items-center justify-between px-4 pb-2 shrink-0">
+            <h2 className="text-sm font-semibold text-foreground">{title}</h2>
+            <button
+              type="button"
+              onClick={handleDismiss}
+              className="p-1.5 rounded-lg hover:bg-muted text-muted-foreground hover:text-foreground transition-colors"
+            >
+              <X className="h-4 w-4" />
+            </button>
+          </div>
+        )}
+
+        {/* Scrollable content */}
+        <div className="flex-1 overflow-y-auto px-4 pb-4 min-h-0">{children}</div>
+      </div>
+    </>
+  );
+}

apps/web/src/components/common/file-library-modal.tsx

@@ -147,7 +147,7 @@ export function FileLibraryModal({ open, onClose, onImport }: FileLibraryModalPr
         className="absolute inset-0 bg-black/50 backdrop-blur-sm cursor-default"
         onClick={onClose}
       />
-      <div className="relative z-10 w-full max-w-lg max-h-[80vh] bg-background border border-border rounded-xl shadow-xl flex flex-col mx-4">
+      <div className="relative z-10 w-full max-w-lg max-h-[80dvh] bg-background border border-border rounded-xl shadow-xl flex flex-col mx-4">
         {/* Header */}
         <div className="flex items-center gap-3 px-4 py-3 border-b border-border shrink-0">
           <FolderOpen className="h-5 w-5 text-primary" />

apps/web/src/components/common/image-viewer.tsx

@@ -1,6 +1,8 @@
+import { useGesture } from "@use-gesture/react";
 import { FileImage, Maximize, Minimize2, ZoomIn, ZoomOut } from "lucide-react";
 import { useCallback, useEffect, useRef, useState } from "react";
 import { formatFileSize } from "@/lib/download";
+import { cn } from "@/lib/utils";
 
 export interface BgPreviewState {
   /** URL of the original image (for blur background) */
@@ -52,8 +54,19 @@ export function ImageViewer({
   const [naturalHeight, setNaturalHeight] = useState<number | null>(null);
   const [fitMode, setFitMode] = useState<"fit" | "actual">("fit");
   const [loadError, setLoadError] = useState(false);
+  const [panOffset, setPanOffset] = useState({ x: 0, y: 0 });
   const containerRef = useRef<HTMLDivElement>(null);
   const imgRef = useRef<HTMLImageElement>(null);
+  const zoomRef = useRef(zoom);
+  const fitModeRef = useRef(fitMode);
+
+  // Keep refs in sync for gesture callbacks
+  useEffect(() => {
+    zoomRef.current = zoom;
+  }, [zoom]);
+  useEffect(() => {
+    fitModeRef.current = fitMode;
+  }, [fitMode]);
 
   const isSvg = filename.toLowerCase().endsWith(".svg");
 
@@ -88,6 +101,7 @@ export function ImageViewer({
   const fitToContainer = useCallback(() => {
     setFitMode("fit");
     setZoom(DEFAULT_ZOOM);
+    setPanOffset({ x: 0, y: 0 });
   }, []);
 
   const actualSize = useCallback(() => {
@@ -103,8 +117,49 @@ export function ImageViewer({
     setNaturalWidth(null);
     setNaturalHeight(null);
     setLoadError(false);
+    setPanOffset({ x: 0, y: 0 });
   }, [src]);
 
+  // Gesture handlers for pinch-to-zoom, ctrl+wheel zoom, and drag-to-pan
+  const initialZoomRef = useRef<number | null>(null);
+  const bind = useGesture(
+    {
+      onPinch: ({ first, offset: [scale], memo }) => {
+        if (first) {
+          initialZoomRef.current = zoomRef.current;
+        }
+        const base = initialZoomRef.current ?? zoomRef.current;
+        const newZoom = Math.max(10, Math.min(1000, base * scale));
+        setZoom(newZoom);
+        setFitMode("actual");
+        return memo;
+      },
+      onWheel: ({ event, delta: [, dy] }) => {
+        if (!(event.ctrlKey || event.metaKey)) return;
+        event.preventDefault();
+        const direction = dy < 0 ? 1 : -1;
+        setZoom((prev) => {
+          const factor = direction > 0 ? 1.1 : 1 / 1.1;
+          return Math.max(10, Math.min(1000, prev * factor));
+        });
+        setFitMode("actual");
+      },
+      onDrag: ({ movement: [mx, my], first, memo }) => {
+        if (fitModeRef.current !== "actual") return;
+        if (first) {
+          memo = { ...panOffset };
+        }
+        const start = memo as { x: number; y: number };
+        setPanOffset({ x: start.x + mx, y: start.y + my });
+        return memo;
+      },
+    },
+    {
+      wheel: { eventOptions: { passive: false } },
+      drag: { filterTaps: true },
+    },
+  );
+
   const previewTransform = [
     cssRotate ? `rotate(${cssRotate}deg)` : "",
     cssFlipH ? "scaleX(-1)" : "",
@@ -131,7 +186,7 @@ export function ImageViewer({
           ...(cssFilter && { filter: cssFilter, transition: "filter 0.15s ease" }),
         }
       : {
-          transform: `scale(${zoom / 100})${previewTransform ? ` ${previewTransform}` : ""}`,
+          transform: `translate(${panOffset.x}px, ${panOffset.y}px) scale(${zoom / 100})${previewTransform ? ` ${previewTransform}` : ""}`,
           transformOrigin: "center center",
           ...checkerBg,
           ...(previewTransform && { transition: "transform 0.25s ease, filter 0.15s ease" }),
@@ -185,7 +240,11 @@ export function ImageViewer({
       {/* Image area */}
       <div
         ref={containerRef}
-        className="flex-1 flex items-center justify-center overflow-auto p-4"
+        {...bind()}
+        className={cn(
+          "flex-1 flex items-center justify-center overflow-auto p-4",
+          fitMode === "actual" && "touch-none",
+        )}
         style={{ backgroundColor: "hsl(var(--muted) / 0.2)" }}
       >
         {loadError ? (

apps/web/src/components/common/side-by-side-comparison.tsx

@@ -39,11 +39,11 @@ export function SideBySideComparison({
           <span className="text-xs font-medium text-muted-foreground uppercase tracking-wide">
             {t.comparison.original}
           </span>
-          <div className="w-full rounded-lg border border-border overflow-hidden flex items-center justify-center bg-muted/30 p-2 min-h-[200px] max-h-[60vh]">
+          <div className="w-full rounded-lg border border-border overflow-hidden flex items-center justify-center bg-muted/30 p-2 min-h-[200px] max-h-[60dvh]">
             <img
               src={beforeSrc}
               alt="Original"
-              className="max-w-full max-h-[56vh] object-contain rounded-sm"
+              className="max-w-full max-h-[56dvh] object-contain rounded-sm"
               draggable={false}
               onLoad={(e) => {
                 const img = e.currentTarget;
@@ -66,11 +66,11 @@ export function SideBySideComparison({
           <span className="text-xs font-medium text-muted-foreground uppercase tracking-wide">
             {t.comparison.processed}
           </span>
-          <div className="w-full rounded-lg border border-border overflow-hidden flex items-center justify-center bg-muted/30 p-2 min-h-[200px] max-h-[60vh]">
+          <div className="w-full rounded-lg border border-border overflow-hidden flex items-center justify-center bg-muted/30 p-2 min-h-[200px] max-h-[60dvh]">
             <img
               src={afterSrc}
               alt="Processed"
-              className="max-w-full max-h-[56vh] object-contain rounded-sm"
+              className="max-w-full max-h-[56dvh] object-contain rounded-sm"
               draggable={false}
               onLoad={(e) => {
                 const img = e.currentTarget;

apps/web/src/components/editor/editor-canvas.tsx

@@ -766,7 +766,7 @@ export function EditorCanvas({
 } = {}) {
   const containerRef = useRef<HTMLDivElement>(null);
   const selectionLayerRef = useRef<Konva.Layer>(null);
-  const { stageRef, handleWheel, fitToScreen } = useCanvasZoom();
+  const { stageRef, handleWheel, fitToScreen, handleTouchMove, handleTouchEnd } = useCanvasZoom();
 
   const zoom = useEditorStore((s) => s.zoom);
   const panOffset = useEditorStore((s) => s.panOffset);
@@ -919,6 +919,8 @@ export function EditorCanvas({
         onMouseMove={handleMouseMove}
         onMouseDown={handleMouseDown}
         onMouseUp={handleMouseUp}
+        onTouchMove={handleTouchMove}
+        onTouchEnd={handleTouchEnd}
         onDragEnd={(e) => {
           if (activeTool === "hand") {
             const stage = e.target.getStage();

apps/web/src/components/help/help-dialog.tsx

@@ -44,7 +44,7 @@ export function HelpDialog({ open, onClose }: HelpDialogProps) {
         onClick={onClose}
       />
 
-      <div className="relative bg-background border border-border rounded-xl shadow-2xl w-full max-w-lg max-h-[85vh] flex flex-col overflow-hidden">
+      <div className="relative bg-background border border-border rounded-xl shadow-2xl w-full max-w-lg max-h-[85dvh] flex flex-col overflow-hidden">
         {/* Header */}
         <div className="flex items-center justify-between p-4 border-b border-border shrink-0">
           <h2 className="text-lg font-semibold text-foreground">{t.help.heading}</h2>

apps/web/src/components/settings/settings-dialog.tsx

@@ -157,7 +157,7 @@ export function SettingsDialog({ open, onClose }: SettingsDialogProps) {
       <div
         role="dialog"
         aria-modal="true"
-        className="relative bg-background border border-border rounded-xl shadow-2xl w-full max-w-3xl h-[85vh] flex overflow-hidden"
+        className="relative bg-background border border-border rounded-xl shadow-2xl w-full max-w-3xl h-[85dvh] flex overflow-hidden"
       >
         {/* Sidebar nav */}
         <div className="w-48 border-r border-border bg-muted/30 p-3 space-y-1 shrink-0">
@@ -634,7 +634,7 @@ function SecuritySection() {
         setMessage({ type: "error", text: t.settings.security.passwordsMismatch });
         return;
       }
-      if (newPassword.length < 4) {
+      if (newPassword.length < 8) {
         setMessage({ type: "error", text: t.settings.security.passwordTooShort });
         return;
       }
@@ -2545,7 +2545,7 @@ function ToolsSection() {
         />
       </div>
 
-      <div className="space-y-4 max-h-[50vh] overflow-y-auto">
+      <div className="space-y-4 max-h-[50dvh] overflow-y-auto">
         {CATEGORIES.filter((cat) => groupedTools.has(cat.id)).map((category) => (
           <div key={category.id}>
             <h4 className="text-xs font-semibold uppercase text-muted-foreground tracking-wider mb-2">
@@ -2706,6 +2706,14 @@ function AboutSection() {
         </div>
       </div>
 
+      <div className="flex items-center gap-4 text-sm">
+        <span className="text-muted-foreground">{t.settings.about.licenseLabel}</span>
+        <div>
+          <span className="font-mono text-foreground">AGPLv3</span>
+          <p className="text-xs text-muted-foreground">{t.settings.about.licenseDescription}</p>
+        </div>
+      </div>
+
       <div className="space-y-2">
         <h4 className="text-sm font-medium text-foreground">{t.settings.about.linksHeading}</h4>
         <div className="flex flex-col gap-1.5">

apps/web/src/components/tools/crop-canvas.tsx

@@ -111,7 +111,7 @@ export function CropCanvas({
             src={imageSrc}
             alt="Crop preview"
             onLoad={handleImageLoad}
-            className="max-w-full max-h-[calc(100vh-12rem)] select-none"
+            className="max-w-full max-h-[calc(100dvh-12rem)] select-none"
             draggable={false}
           />
         </ReactCrop>

apps/web/src/components/tools/resize-settings.tsx

@@ -202,7 +202,7 @@ export function ResizeControls({ settings: initialSettings, onChange }: ResizeCo
 
       {/* Presets tab */}
       {tab === "presets" && (
-        <div className="space-y-3 max-h-[50vh] overflow-y-auto pe-1">
+        <div className="space-y-3 max-h-[50dvh] overflow-y-auto pe-1">
           {platforms.map((platform) => (
             <div key={platform}>
               <p className="text-xs font-medium text-muted-foreground mb-1.5">{platform}</p>

apps/web/src/components/tools/smart-crop-settings.tsx

@@ -296,7 +296,7 @@ export function SmartCropControls({ settings: initialSettings, onChange }: Smart
           </div>
 
           {subjectTab === "presets" ? (
-            <div className="space-y-3 max-h-[50vh] overflow-y-auto pe-1">
+            <div className="space-y-3 max-h-[50dvh] overflow-y-auto pe-1">
               {platforms.map((platform) => (
                 <div key={platform}>
                   <p className="text-xs font-medium text-muted-foreground mb-1.5">{platform}</p>

apps/web/src/hooks/use-canvas-zoom.ts

@@ -14,6 +14,8 @@ export function useCanvasZoom() {
   const zoom = useEditorStore((s) => s.zoom);
   const panOffset = useEditorStore((s) => s.panOffset);
   const tweenRef = useRef<Konva.Tween | null>(null);
+  const lastDistRef = useRef<number | null>(null);
+  const lastCenterRef = useRef<{ x: number; y: number } | null>(null);
 
   const animateZoom = useCallback(
     (targetZoom: number, targetPos: { x: number; y: number }) => {
@@ -114,5 +116,58 @@ export function useCanvasZoom() {
     [animateZoom],
   );
 
-  return { stageRef, handleWheel, fitToScreen, zoomTo };
+  const handleTouchMove = useCallback(
+    (e: Konva.KonvaEventObject<TouchEvent>) => {
+      const touches = e.evt.touches;
+      if (touches.length < 2) return;
+
+      const t1 = touches[0];
+      const t2 = touches[1];
+      const newDist = Math.hypot(t2.clientX - t1.clientX, t2.clientY - t1.clientY);
+      const newCenter = {
+        x: (t1.clientX + t2.clientX) / 2,
+        y: (t1.clientY + t2.clientY) / 2,
+      };
+
+      if (lastDistRef.current !== null && lastCenterRef.current !== null) {
+        const scaleDelta = newDist / lastDistRef.current;
+        const currentZoom = useEditorStore.getState().zoom;
+        const currentPan = useEditorStore.getState().panOffset;
+        const newZoom = Math.max(0.01, Math.min(64, currentZoom * scaleDelta));
+
+        // Keep pinch center stable
+        const mousePointTo = {
+          x: (newCenter.x - currentPan.x) / currentZoom,
+          y: (newCenter.y - currentPan.y) / currentZoom,
+        };
+        const newPos = {
+          x: newCenter.x - mousePointTo.x * newZoom,
+          y: newCenter.y - mousePointTo.y * newZoom,
+        };
+
+        const stage = stageRef.current;
+        if (stage) {
+          stage.scaleX(newZoom);
+          stage.scaleY(newZoom);
+          stage.x(newPos.x);
+          stage.y(newPos.y);
+          stage.batchDraw();
+        }
+        setZoom(newZoom);
+        setPanOffset(newPos);
+      }
+
+      lastDistRef.current = newDist;
+      lastCenterRef.current = newCenter;
+      e.evt.preventDefault();
+    },
+    [setZoom, setPanOffset],
+  );
+
+  const handleTouchEnd = useCallback(() => {
+    lastDistRef.current = null;
+    lastCenterRef.current = null;
+  }, []);
+
+  return { stageRef, handleWheel, fitToScreen, zoomTo, handleTouchMove, handleTouchEnd };
 }

apps/web/src/hooks/use-mobile.ts

@@ -2,21 +2,38 @@ import { useEffect, useState } from "react";
 
 const MOBILE_BREAKPOINT = 768;
 
+/**
+ * Generic media-query hook. Returns true when the query matches.
+ * Guards against missing `window.matchMedia` for test environments.
+ */
+export function useMediaQuery(query: string): boolean {
+  const [matches, setMatches] = useState(() => {
+    if (typeof window === "undefined" || typeof window.matchMedia !== "function") return false;
+    return window.matchMedia(query).matches;
+  });
+
+  useEffect(() => {
+    if (typeof window.matchMedia !== "function") return;
+    const mq = window.matchMedia(query);
+    const handler = (e: MediaQueryListEvent) => setMatches(e.matches);
+    mq.addEventListener("change", handler);
+    setMatches(mq.matches);
+    return () => mq.removeEventListener("change", handler);
+  }, [query]);
+
+  return matches;
+}
+
 /**
  * Returns true when the viewport width is below the mobile breakpoint (768px).
  */
 export function useMobile(): boolean {
-  const [isMobile, setIsMobile] = useState(() =>
-    typeof window !== "undefined" ? window.innerWidth < MOBILE_BREAKPOINT : false,
-  );
+  return useMediaQuery(`(max-width: ${MOBILE_BREAKPOINT - 1}px)`);
+}
 
-  useEffect(() => {
-    const mq = window.matchMedia(`(max-width: ${MOBILE_BREAKPOINT - 1}px)`);
-    const handler = (e: MediaQueryListEvent) => setIsMobile(e.matches);
-    mq.addEventListener("change", handler);
-    setIsMobile(mq.matches);
-    return () => mq.removeEventListener("change", handler);
-  }, []);
-
-  return isMobile;
+/**
+ * Returns true when the primary input device is a coarse pointer (touch).
+ */
+export function useTouchDevice(): boolean {
+  return useMediaQuery("(pointer: coarse)");
 }

apps/web/src/pages/automate-page.tsx

@@ -546,7 +546,7 @@ export function AutomatePage() {
                 className="fixed inset-0 z-40 bg-black/50 backdrop-blur-sm"
                 onClick={() => setMobileToolPaletteOpen(false)}
               />
-              <div className="fixed inset-x-0 bottom-0 z-50 bg-background border-t border-border rounded-t-2xl shadow-xl max-h-[70vh] flex flex-col animate-in slide-in-from-bottom">
+              <div className="fixed inset-x-0 bottom-0 z-50 bg-background border-t border-border rounded-t-2xl shadow-xl max-h-[70dvh] flex flex-col animate-in slide-in-from-bottom">
                 <div className="flex items-center justify-between px-4 py-3 border-b border-border shrink-0">
                   <h2 className="text-sm font-semibold text-foreground">{t.automate.addTool}</h2>
                   <button

apps/web/src/pages/files-page.tsx

@@ -77,7 +77,7 @@ export function FilesPage() {
                 if (e.key === "Escape") setShowDetails(false);
               }}
             >
-              <div className="absolute bottom-0 left-0 right-0 bg-background rounded-t-xl p-4 max-h-[70vh] overflow-y-auto">
+              <div className="absolute bottom-0 left-0 right-0 bg-background rounded-t-xl p-4 max-h-[70dvh] overflow-y-auto">
                 <div className="flex justify-between items-center mb-3">
                   <span className="text-sm font-semibold">{t.files.fileDetailsHeading}</span>
                   <button type="button" onClick={() => setShowDetails(false)}>

apps/web/src/pages/tool-page.tsx

@@ -11,6 +11,7 @@ import { Suspense, useCallback, useEffect, useMemo, useRef, useState } from "rea
 import type { Crop } from "react-image-crop";
 import { useParams } from "react-router-dom";
 import { BeforeAfterSlider } from "@/components/common/before-after-slider";
+import { BottomSheet } from "@/components/common/bottom-sheet";
 import { Dropzone } from "@/components/common/dropzone";
 import { type BgPreviewState, ImageViewer } from "@/components/common/image-viewer";
 import { ReviewPanel } from "@/components/common/review-panel";
@@ -213,7 +214,7 @@ export function ToolPage() {
     },
     [navigateNext, navigatePrev],
   );
-  const [mobileSettingsOpen, setMobileSettingsOpen] = useState(true);
+  const [mobileSettingsOpen, setMobileSettingsOpen] = useState(false);
   const [previewTransform, setPreviewTransform] = useState<PreviewTransform | null>(null);
   const [previewFilter, setPreviewFilter] = useState<string>("");
   const [imageWrapperStyle, setImageWrapperStyle] = useState<React.CSSProperties | null>(null);
@@ -274,7 +275,7 @@ export function ToolPage() {
     setEraserMaskedCount(0);
     setEraserBrushSize(30);
     setEraserSliderInitPos(null);
-    setMobileSettingsOpen(true);
+    setMobileSettingsOpen(false);
   }, [toolId]);
 
   const toolAccept = registryEntry?.accept;
@@ -777,7 +778,7 @@ export function ToolPage() {
     );
   }
 
-  // Mobile layout: settings above dropzone (stacked)
+  // Mobile layout: full-height image area with BottomSheet for settings
   if (isMobile) {
     return (
       <AppLayout showToolPanel={false}>
@@ -795,18 +796,11 @@ export function ToolPage() {
               onClick={() => setMobileSettingsOpen(!mobileSettingsOpen)}
               className="px-3 py-1.5 rounded-lg border border-border text-xs text-muted-foreground hover:bg-muted"
             >
-              {mobileSettingsOpen ? t.toolPage.hideSettings : t.common.settings}
+              {t.common.settings}
             </button>
           </div>
 
-          {/* Collapsible settings */}
-          {mobileSettingsOpen && (
-            <div className="p-4 border-b border-border space-y-3 shrink-0 max-h-[40vh] overflow-y-auto">
-              {renderSettingsContent()}
-            </div>
-          )}
-
-          {/* Main area: image viewer */}
+          {/* Main area: image viewer (full height) */}
           <section
             aria-label="Image area"
             className="flex-1 flex flex-col min-h-0 min-w-0"
@@ -825,6 +819,15 @@ export function ToolPage() {
               />
             )}
           </section>
+
+          {/* Settings BottomSheet */}
+          <BottomSheet
+            open={mobileSettingsOpen}
+            onClose={() => setMobileSettingsOpen(false)}
+            title={t.common.settings}
+          >
+            <div className="settings-container space-y-3">{renderSettingsContent()}</div>
+          </BottomSheet>
         </div>
       </AppLayout>
     );
@@ -835,7 +838,7 @@ export function ToolPage() {
     <AppLayout showToolPanel={false}>
       <div className="flex h-full w-full">
         {/* Tool Settings Panel */}
-        <div className="w-72 border-r border-border p-4 space-y-4 overflow-y-auto shrink-0">
+        <div className="settings-container w-72 border-r border-border p-4 space-y-4 overflow-y-auto shrink-0">
           <div className="flex items-center gap-3">
             <div className="p-2 rounded-lg bg-primary text-primary-foreground">
               <IconComponent className="h-5 w-5" />

apps/web/src/styles/globals.css

@@ -105,3 +105,24 @@ input[type="range"]::-moz-range-track {
   direction: ltr;
   text-align: left;
 }
+
+/* Container queries for responsive settings panels */
+.settings-container {
+  container-type: inline-size;
+}
+
+@container (min-width: 400px) {
+  .settings-container .settings-grid-auto {
+    grid-template-columns: repeat(2, 1fr);
+  }
+}
+
+/* Touch-friendly targets for coarse pointer devices */
+@media (pointer: coarse) {
+  input[type="range"] { height: 8px; padding: 8px 0; }
+  input[type="range"]::-webkit-slider-thumb { width: 24px; height: 24px; border-width: 3px; }
+  input[type="range"]::-moz-range-thumb { width: 24px; height: 24px; border-width: 3px; }
+  input[type="range"]::-moz-range-track { height: 8px; }
+  input[type="checkbox"] { width: 20px; height: 20px; }
+  button, [role="button"], a { touch-action: manipulation; }
+}