Add fullscreen expansion to schematic and waveform viewers

Repurpose the Maximize2 button in SchematicViewer as a fullscreen
toggle (was reset-zoom; percentage label is now clickable for that).
Add matching fullscreen toggle to WaveformViewer alongside the scope
button. Both use a shared useFullscreen hook for Escape-to-exit and
body scroll lock. In fullscreen mode, the SVG canvas and plot areas
fill the viewport with proper dimension tracking via ResizeObserver.

frontend/src/components/notebook/output/SchematicViewer.tsx

@@ -1,6 +1,8 @@
 import { useState, useRef, useCallback, useEffect } from 'react';
-import { ZoomIn, ZoomOut, Maximize2, Download } from 'lucide-react';
+import { ZoomIn, ZoomOut, Maximize2, Minimize2, Download } from 'lucide-react';
 import DOMPurify from 'dompurify';
+import { cn } from '../../../lib/cn';
+import { useFullscreen } from '../../../lib/useFullscreen';
 
 interface EditState {
   component: string;
@@ -29,6 +31,7 @@ function sanitizeSvg(raw: string): string {
 export function SchematicViewer({ svg, componentMap, onValueChange }: SchematicViewerProps) {
   const [zoomIndex, setZoomIndex] = useState(2); // Start at 100%
   const [editState, setEditState] = useState<EditState | null>(null);
+  const { isFullscreen, toggleFullscreen } = useFullscreen();
   const containerRef = useRef<HTMLDivElement>(null);
   const svgWrapperRef = useRef<HTMLDivElement>(null);
   const inputRef = useRef<HTMLInputElement>(null);
@@ -189,7 +192,7 @@ export function SchematicViewer({ svg, componentMap, onValueChange }: SchematicV
   );
 
   return (
-    <div className="relative">
+    <div className={cn('relative', isFullscreen && 'fixed inset-0 z-50 bg-slate-950 flex flex-col')}>
       {/* Toolbar */}
       <div className="flex items-center gap-1 px-3 py-1.5 border-b border-slate-700/50 bg-slate-800/50">
         <button
@@ -200,9 +203,13 @@ export function SchematicViewer({ svg, componentMap, onValueChange }: SchematicV
         >
           <ZoomOut className="w-3.5 h-3.5" />
         </button>
-        <span className="text-xs text-slate-500 tabular-nums w-10 text-center">
+        <button
+          onClick={fitToWidth}
+          className="text-xs text-slate-500 hover:text-slate-300 tabular-nums w-10 text-center transition-colors"
+          title="Reset to 100%"
+        >
           {Math.round(zoom * 100)}%
-        </span>
+        </button>
         <button
           onClick={zoomIn}
           disabled={zoomIndex === ZOOM_STEPS.length - 1}
@@ -212,11 +219,15 @@ export function SchematicViewer({ svg, componentMap, onValueChange }: SchematicV
           <ZoomIn className="w-3.5 h-3.5" />
         </button>
         <button
-          onClick={fitToWidth}
+          onClick={toggleFullscreen}
           className="p-1 rounded text-slate-400 hover:text-slate-200 hover:bg-slate-700/50 transition-colors"
-          title="Reset zoom"
+          title={isFullscreen ? 'Exit fullscreen (Esc)' : 'Fullscreen'}
         >
-          <Maximize2 className="w-3.5 h-3.5" />
+          {isFullscreen ? (
+            <Minimize2 className="w-3.5 h-3.5" />
+          ) : (
+            <Maximize2 className="w-3.5 h-3.5" />
+          )}
         </button>
         <div className="flex-1" />
         {componentMap && Object.keys(componentMap).length > 0 && (
@@ -237,8 +248,11 @@ export function SchematicViewer({ svg, componentMap, onValueChange }: SchematicV
       {/* SVG Canvas */}
       <div
         ref={containerRef}
-        className="overflow-auto bg-white rounded-b-lg relative"
+        className={cn(
-        style={{ maxHeight: '500px' }}
+          'overflow-auto bg-white relative',
+          isFullscreen ? 'flex-1' : 'rounded-b-lg',
+        )}
+        style={isFullscreen ? undefined : { maxHeight: '500px' }}
       >
         <div
           ref={svgWrapperRef}

frontend/src/components/notebook/output/WaveformViewer.tsx

@@ -1,6 +1,9 @@
 import { useRef, useEffect, useState, useCallback } from 'react';
+import { Maximize2, Minimize2 } from 'lucide-react';
 import type { WaveformData } from '../../../lib/types';
 import { formatAxisValue, TRACE_COLORS } from '../../../lib/waveform-utils';
+import { cn } from '../../../lib/cn';
+import { useFullscreen } from '../../../lib/useFullscreen';
 import { ScopeWaveformViewer } from './ScopeWaveformViewer';
 
 // uPlot is a vanilla JS lib; import it and its CSS
@@ -79,9 +82,11 @@ function buildOpts(
 function TransientPlot({
   waveform,
   width,
+  height,
 }: {
   waveform: WaveformData;
   width: number;
+  height?: number;
 }) {
   const plotRef = useRef<HTMLDivElement>(null);
   const uplotRef = useRef<uPlot | null>(null);
@@ -102,7 +107,7 @@ function TransientPlot({
     // Determine y-axis type from variable types
     const yType =
       waveform.variables.length > 1 ? waveform.variables[1].type : 'voltage';
-    const opts = buildOpts(waveform, width, 280, waveform.x_type, yType);
+    const opts = buildOpts(waveform, width, height ?? 280, waveform.x_type, yType);
 
     const u = new uPlot(opts, data, plotRef.current);
     uplotRef.current = u;
@@ -111,7 +116,7 @@ function TransientPlot({
       u.destroy();
       uplotRef.current = null;
     };
-  }, [waveform, width]);
+  }, [waveform, width, height]);
 
   return <div ref={plotRef} />;
 }
@@ -119,9 +124,11 @@ function TransientPlot({
 function ACPlot({
   waveform,
   width,
+  height,
 }: {
   waveform: WaveformData;
   width: number;
+  height?: number;
 }) {
   const magRef = useRef<HTMLDivElement>(null);
   const phaseRef = useRef<HTMLDivElement>(null);
@@ -147,7 +154,8 @@ function ACPlot({
         ),
       ];
 
-      const magOpts = buildOpts(waveform, width, 220, 'frequency', 'dB');
+      const magH = height ? Math.round(height * 0.55) : 220;
+      const magOpts = buildOpts(waveform, width, magH, 'frequency', 'dB');
       magOpts.series = [
         { label: 'Frequency' },
         ...magTraces.map((name, i) => ({
@@ -171,10 +179,11 @@ function ACPlot({
         ),
       ];
 
+      const phaseH = height ? height - Math.round(height * 0.55) : 180;
       const phaseOpts = buildOpts(
         waveform,
         width,
-        180,
+        phaseH,
         'frequency',
         'degrees',
       );
@@ -198,7 +207,7 @@ function ACPlot({
       magPlotRef.current = null;
       phasePlotRef.current = null;
     };
-  }, [waveform, width]);
+  }, [waveform, width, height]);
 
   return (
     <div className="space-y-2">
@@ -236,25 +245,28 @@ function ScopeToggleIcon({ active }: { active: boolean }) {
 export function WaveformViewer({ waveform, className }: WaveformViewerProps) {
   const containerRef = useRef<HTMLDivElement>(null);
   const [width, setWidth] = useState(0);
+  const [height, setHeight] = useState(0);
+  const { isFullscreen, toggleFullscreen } = useFullscreen();
   const [scopeMode, setScopeMode] = useState(() => {
     try { return localStorage.getItem('spicebook-scope-mode') === 'true'; }
     catch { return false; }
   });
 
-  const updateWidth = useCallback(() => {
+  const updateDimensions = useCallback(() => {
     if (containerRef.current) {
       setWidth(containerRef.current.clientWidth);
+      setHeight(containerRef.current.clientHeight);
     }
   }, []);
 
   useEffect(() => {
-    updateWidth();
+    updateDimensions();
-    const observer = new ResizeObserver(updateWidth);
+    const observer = new ResizeObserver(updateDimensions);
     if (containerRef.current) {
       observer.observe(containerRef.current);
     }
     return () => observer.disconnect();
-  }, [updateWidth]);
+  }, [updateDimensions]);
 
   const toggleScope = useCallback(() => {
     setScopeMode(prev => {
@@ -268,36 +280,71 @@ export function WaveformViewer({ waveform, className }: WaveformViewerProps) {
   const isEmpty =
     traceCount === 0 && !waveform.y_magnitude_db && !waveform.y_phase_deg;
 
+  // In fullscreen, subtract toolbar + padding from available height
+  const plotWidth = isFullscreen ? Math.max(width - 32, 100) : width;
+  const plotHeight = isFullscreen ? Math.max(height - 80, 200) : undefined;
+
   return (
-    <div ref={containerRef} className={`relative ${className || ''}`}>
+    <div
-      {/* Scope toggle button */}
+      ref={containerRef}
+      className={cn(
+        'relative',
+        className,
+        isFullscreen && 'fixed inset-0 z-50 bg-slate-900 flex flex-col',
+      )}
+    >
+      {/* Control buttons */}
       {!isEmpty && (
-        <button
+        <div
-          type="button"
+          className={cn(
-          onClick={toggleScope}
+            'flex items-center gap-1 z-10',
-          className="absolute top-1 right-1 z-10 p-1 rounded hover:bg-slate-700/50 transition-colors"
+            isFullscreen
-          aria-label={scopeMode ? 'Exit oscilloscope view' : 'Switch to oscilloscope view'}
+              ? 'px-4 py-2 justify-end border-b border-slate-700/50'
-          title={scopeMode ? 'Standard view' : 'Oscilloscope view'}
+              : 'absolute top-1 right-1',
+          )}
         >
-          <ScopeToggleIcon active={scopeMode} />
+          <button
-        </button>
+            type="button"
+            onClick={toggleFullscreen}
+            className="p-1 rounded text-slate-400 hover:text-slate-200 hover:bg-slate-700/50 transition-colors"
+            title={isFullscreen ? 'Exit fullscreen (Esc)' : 'Fullscreen'}
+          >
+            {isFullscreen ? (
+              <Minimize2 className="w-[18px] h-[18px]" />
+            ) : (
+              <Maximize2 className="w-[18px] h-[18px]" />
+            )}
+          </button>
+          <button
+            type="button"
+            onClick={toggleScope}
+            className="p-1 rounded hover:bg-slate-700/50 transition-colors"
+            aria-label={scopeMode ? 'Exit oscilloscope view' : 'Switch to oscilloscope view'}
+            title={scopeMode ? 'Standard view' : 'Oscilloscope view'}
+          >
+            <ScopeToggleIcon active={scopeMode} />
+          </button>
+        </div>
       )}
 
-      {isEmpty ? (
+      {/* Plot area */}
-        <div className="text-slate-500 text-sm py-4 text-center">
+      <div className={cn(isFullscreen && 'flex-1 min-h-0 px-4 pb-4')}>
-          No waveform data to display.
+        {isEmpty ? (
-        </div>
+          <div className="text-slate-500 text-sm py-4 text-center">
-      ) : scopeMode ? (
+            No waveform data to display.
-        <ScopeWaveformViewer
+          </div>
-          waveform={waveform}
+        ) : scopeMode ? (
-          width={width}
+          <ScopeWaveformViewer
-          onExitScope={toggleScope}
+            waveform={waveform}
-        />
+            width={plotWidth}
-      ) : waveform.is_complex ? (
+            onExitScope={toggleScope}
-        <ACPlot waveform={waveform} width={width} />
+          />
-      ) : (
+        ) : waveform.is_complex ? (
-        <TransientPlot waveform={waveform} width={width} />
+          <ACPlot waveform={waveform} width={plotWidth} height={plotHeight} />
-      )}
+        ) : (
+          <TransientPlot waveform={waveform} width={plotWidth} height={plotHeight} />
+        )}
+      </div>
     </div>
   );
 }

frontend/src/lib/useFullscreen.ts

@@ -0,0 +1,39 @@
+import { useState, useCallback, useEffect } from 'react';
+
+/**
+ * Manages fullscreen overlay state with escape-to-exit and body scroll lock.
+ */
+export function useFullscreen() {
+  const [isFullscreen, setIsFullscreen] = useState(false);
+
+  const toggleFullscreen = useCallback(() => {
+    setIsFullscreen((prev) => !prev);
+  }, []);
+
+  // Escape key exits fullscreen (capture phase so it fires before other handlers)
+  useEffect(() => {
+    if (!isFullscreen) return;
+    const handler = (e: KeyboardEvent) => {
+      if (e.key === 'Escape') {
+        setIsFullscreen(false);
+        e.stopPropagation();
+      }
+    };
+    document.addEventListener('keydown', handler, true);
+    return () => document.removeEventListener('keydown', handler, true);
+  }, [isFullscreen]);
+
+  // Prevent background scrolling
+  useEffect(() => {
+    if (isFullscreen) {
+      document.body.style.overflow = 'hidden';
+    } else {
+      document.body.style.overflow = '';
+    }
+    return () => {
+      document.body.style.overflow = '';
+    };
+  }, [isFullscreen]);
+
+  return { isFullscreen, toggleFullscreen };
+}