DeepSeek V4.1 Flash (Venice) on Build a full game (code, art, audio) with AI

{"turn": 1, "response": {"id": "chatcmpl-f4ca33f573144b5b8622673737987f1b", "object": "chat.completion", "created": 1792021762, "model": "deepseek-v4-1-flash", "choices": [{"index": 0, "message": {"role": "assistant", "content": "", "reasoning_content": "Let me build a complete single-file arcade game. Let me check the working directory first.\n\nLet me plan the game:\n\nTheme: capybara crossing a river. Frogger-like: capybara starts at bottom bank, must cross a river with logs/turtles moving, and a road? Actually \"crossing a river\" \u2014 let's do a Frogger-style: bottom bank \u2192 river with logs (ride them) \u2192 top bank. Score for reaching top, then it resets to bottom with increased difficulty. Lives, timer maybe.\n\nLet me design:\n- Canvas 480x640 or so, scaled responsive.\n- Rows: bottom safe bank (grass), then 5 river lanes with logs/lily pads moving left/right, then top bank (grass) with goal.\n- Capybara moves with arrow keys / WASD, one hop at a time (grid-based) \u2014 classic Frogger.\n- If capybara is in water and not on a log \u2192 drown \u2192 lose life.\n- Reaching top bank \u2192 score += 100 + time bonus, difficulty increases (speed up), respawn at bottom.\n- Lives = 3. Game over when 0 lives.\n- Score, high score in localStorage.\n- Sounds: hop (short blip), splash/drown (noise), score (arpeggio), game over. Background music: simple loop with oscillators scheduled.\n- Title screen with Start button (click or Enter/Space).\n- Procedural art: draw capybara with shapes (rounded body, ears, eyes, nose), logs as brown rounded rects with rings, water with animated waves, grass with tufts, lily pads.\n\nLet me write it carefully.\n\nGrid: columns = 11? Let's use tile size 40, width 480 \u2192 12 columns. Height: rows: bottom bank 2 rows (80), river 6 rows (240), top bank 2 rows (80) = 400... let's do canvas 480x600: bottom bank 80, river 400? Hmm.\n\nLet's define:\n- TILE = 40\n- COLS = 12 \u2192 width 480\n- Rows: \n  - row 0-1: top bank (goal) \u2014 2 rows = 80\n  - rows 2-8: river lanes (7 lanes) = 280\n  - rows 9-10: bottom bank (start) = 80\n  - total height = 440. Add HUD area at top? Let's put HUD drawn over canvas top with semi-transparent bar, or make canvas 480x480 and HUD separate HTML. Simpler: canvas 480x520 with 40px HUD strip at top.\n\nActually let's do: canvas width 480, height 560. HUD strip 40px at top (y 0..40). Then playfield y 40..560 = 520 = 13 rows of 40.\n- Playfield rows (index 0..12):\n  - 0,1: top bank (goal) \u2014 grass\n  - 2..8: river (7 lanes)\n  - 9..12: bottom bank (4 rows grass) \u2014 start at row 12.\n\nHmm 4 rows of grass at bottom is a lot. Let's do:\n- 0,1: top bank (2 rows)\n- 2..9: river (8 lanes)\n- 10,11,12: bottom bank (3 rows), start row 12.\n\nTotal 13 rows * 40 = 520. Good.\n\nCapybara position: grid col (0..11), row. Start at row 12, col 5 or 6.\n\nMovement: arrow keys move one tile. In river rows, capybara must be on a log; logs move continuously, so capybara's x position is continuous (float) when riding. So I'll track capybara x in pixels (float) and row integer. When hopping, x snaps to grid center of target col. When riding a log, x += log speed * dt.\n\nCollision: for river rows, check if capybara's center x is within any log's span. If not \u2192 drown.\n\nAlso capybara can't move off screen horizontally (clamp) \u2014 or wrap? Clamp.\n\nLogs: each lane has a set of logs with x positions, width (in tiles: 2-4 tiles), speed (px/s), direction. Wrap around: when log goes off right edge, reappear at left with gap.\n\nLily pads: static? Let's have some lanes with logs, some with lily pads (static platforms) \u2014 but static platforms in a river with moving logs is fine. Actually let's keep all lanes moving logs/turtles for simplicity, with varying speeds and directions.\n\nDifficulty: level increases \u2192 speeds multiply by 1 + 0.12*level, and maybe more logs gaps. Also capybara must reach top; each successful crossing increments level.\n\nTimer: optional. Let's add a per-life timer? Keep it simpler: no timer, but score bonus for speed. Actually increasing difficulty via speed is enough. Let's add a \"current\" that pushes? Nah.\n\nLet me add a timer bar for tension: each crossing attempt has a time limit (e.g., 30s decreasing). If time runs out \u2192 lose life. Hmm, adds complexity but nice. I'll include a simple timer that resets on each spawn, decreasing with level. Actually let's keep it: timer per life, 30s at level 1, min 12s.\n\nHmm, but timer per life means you must cross quickly. Fine.\n\nLet me reconsider: simpler and fun \u2014 no timer, but score bonus based on remaining... no. I'll include the timer; it's classic Frogger.\n\nActually, let me skip the timer to reduce bug surface, and instead make difficulty via speed + more lanes? No, lanes fixed. Speed increase is fine, plus logs get shorter (harder to land). Let's do speed increase and slight log width reduction.\n\nHmm, I'll include a timer \u2014 it's a nice touch and not too hard. Let's do it.\n\nLet me now write the code.\n\nStructure:\n\n```html\n<!DOCTYPE html>\n<html>\n<head>\n<meta charset=\"utf-8\">\n<meta name=\"viewport\" content=\"width=device-width,initial-scale=1,user-scalable=no\">\n<title>Capybara Crossing</title>\n<style>...</style>\n</head>\n<body>\n<div id=\"wrap\">\n  <canvas id=\"game\" width=\"480\" height=\"560\"></canvas>\n</div>\n<script> ... </script>\n</body>\n</html>\n```\n\nCSS: center, dark background, canvas scaled with max-height, image-rendering pixelated? No, we draw smooth shapes. Use `canvas { display:block; }` and scale via CSS width based on aspect ratio.\n\nLet me handle resizing: set canvas CSS size to fit window preserving aspect.\n\nInput: keydown for arrows/WASD, Space/Enter for start/restart. Also touch: swipe? Add simple on-screen buttons? Maybe add touch swipe support for mobile. I'll add basic swipe detection on canvas. Keep it optional but nice.\n\nAudio: Web Audio API. Create AudioContext on first user gesture (click Start or keypress). \n\nSound functions:\n- `beep(freq, dur, type, gain, when)` helper.\n- hop: short square blip 440\u2192660.\n- splash: white noise burst with lowpass, decaying.\n- score: arpeggio C-E-G-C.\n- gameover: descending tones.\n- Music: a loop scheduled with setInterval or lookahead scheduler. Simple: a bass line + melody using oscillators, scheduled every beat. Use a scheduler with lookahead.\n\nLet me write a simple music scheduler:\n\n```js\nconst music = {\n  playing:false,\n  nextTime:0,\n  step:0,\n  bpm: 100,\n  pattern: [...],\n};\n```\n\nUse `setInterval(scheduler, 25)` with lookahead 0.1s.\n\nMelody: pentatonic notes. Bass: root notes.\n\nLet me define notes as frequencies.\n\n```js\nfunction noteFreq(n){ return 440*Math.pow(2,(n-69)/12); } // MIDI\n```\n\nMelody pattern (MIDI): [72,76,79,76, 74,77,81,77, ...] etc. Let's make a 16-step pattern with some rests.\n\nBass: [48,48,55,48, 53,53,48,48] etc.\n\nI'll write:\n\n```js\nconst MEL = [76,null,79,null,81,null,79,null, 76,null,74,null,72,null,74,null];\nconst BASS = [40,null,40,null,45,null,45,null, 43,null,43,null,38,null,38,null];\n```\n\nEach step = eighth note at 100bpm \u2192 0.3s per step. 16 steps = 4.8s loop.\n\nMusic should be gentle/ambient. Use triangle for melody with soft gain, sine for bass.\n\nAlso add a soft \"water\" pad? Keep it simple.\n\nNow the game code.\n\nConstants:\n```js\nconst TILE=40, COLS=12, ROWS=13, HUD=40;\nconst W=COLS*TILE, H=HUD+ROWS*TILE; // 480, 560\n```\n\nRow helpers: `rowY(r) = HUD + r*TILE`.\n\nLanes: rows 2..9 (8 lanes). Each lane: {row, dir, speed, logs:[{x,w}], gap, ...}\n\nLog generation: for a lane, create logs spaced with a gap. Let's define lane with `count` logs, each width w tiles, spacing computed so they're evenly distributed across a virtual width of W + something.\n\nSimplest: lane has `logs` array of {x, w}. Total cycle length L = W + maxGap. Place logs at positions x_i = i*(L/count). When a log's x > W + something, wrap to x -= L.\n\nLet's define: `lane.period = W + lane.gapPx` where gapPx is the gap between logs. Actually let's do: each lane has `n` logs, each of width `w` px, and gap `g` px. Period P = n*(w+g). Logs at x = i*(w+g) + offset. Wrap: if dir>0 and x > W \u2192 x -= P. If dir<0 and x + w < 0 \u2192 x += P.\n\nThat works if P >= W + w so that logs don't overlap when wrapping... Actually with wrap by P, positions are always i*(w+g)+offset mod P, and since P = n*(w+g), the set of positions is {offset + k*(w+g) mod P}. If P > W + w, there's a visible gap. Let's ensure P >= W + w + g. Hmm, simpler: choose n, w, g such that n*(w+g) >= W + w + 20. Then at any time, at most n logs visible and gaps are consistent.\n\nLet me just compute: for a lane, given w (log width px) and g (gap px), n = ceil((W + w + g) / (w+g)). Then P = n*(w+g). Good.\n\nLog widths: 2-4 tiles \u2192 80-160px. Gap: 90-140px. So w+g ~ 200-280, n = ceil((480+160+140)/200)= ceil(3.9)=4. P=800. Fine.\n\nSpeeds: 40-110 px/s, direction alternating.\n\nLevel scaling: speed *= (1 + 0.10*(level-1)), capped. Also gap increases slightly? Increasing gap makes it easier. Decreasing gap makes harder. Let's increase speed only, plus maybe reduce log width slightly at high levels. Keep speed.\n\nCapybara:\n```js\nconst player = { col:5, row:12, x: W/2, y:0, riding:null, alive:true, hopT:0 };\n```\nx in px (center), row integer. y = rowY(row) + TILE/2.\n\nHop animation: when moving, animate y/x over 0.12s. Let's keep it simple: instant snap but with a small squash animation. Actually a smooth hop looks better. Let's do: player has `fromX, fromY, toX, toY, hopT` and interpolate. During hop, riding is null (can't drown mid-hop? or check at end). Let's check drowning only when not hopping.\n\nHmm, but if you hop onto water you should drown. Let's check at end of hop: if row is river and no log under \u2192 drown.\n\nActually simpler and more forgiving: check continuously when not hopping.\n\nLet me implement hop:\n```js\nfunction tryMove(dx, dy){\n  if (state!=='play' || player.hopT>0) return;\n  const nc = clamp(player.col+dx,0,COLS-1);\n  const nr = clamp(player.row+dy,0,ROWS-1);\n  if (nc===player.col && nr===player.row) return;\n  player.col=nc; player.row=nr;\n  player.fromX=player.x; player.fromY=player.y;\n  player.toX = nc*TILE+TILE/2;\n  player.toY = rowY(nr)+TILE/2;\n  player.hopT = HOP_DUR;\n  sfx.hop();\n}\n```\nDuring hop, x,y interpolate. After hop completes, if row is river, check log; if none \u2192 drown.\n\nBut while riding, x changes continuously. When hopping from a log, fromX = current x. Good.\n\nRiding: after hop completes and on a log, set player.riding = log. Each frame, player.x += log.speed*dt*dir. If player.x goes off screen \u2192 drown (or clamp?). In Frogger, going off screen = death. Let's drown.\n\nAlso while riding, if the log wraps (teleports), the player should teleport too. Handle: when a log wraps, if player.riding === log, adjust player.x by the same delta.\n\nLet's handle wrap in the log update: \n```js\nconst oldX = log.x;\nlog.x += lane.speed*lane.dir*dt;\nif (lane.dir>0 && log.x > W) log.x -= P;\nif (lane.dir<0 && log.x + log.w < 0) log.x += P;\nif (player.riding===log) player.x += log.x - oldX;\n```\nGood.\n\nDrowning check while riding: if player.x < -TILE/2 or > W+TILE/2 \u2192 drown.\n\nAlso if riding and the log... fine.\n\nGoal: when player.row <= 1 (top bank rows 0,1) \u2192 success. Actually reaching row 1 or 0. Let's say reaching row 1 counts (top bank). Then score.\n\nOn success: score += 100 + level*10 + timeBonus. level++. Reset player to start. Reset timer. Play score sound. Maybe show a brief \"flash\".\n\nLives: 3. On drown \u2192 lives--, if 0 \u2192 gameover, else respawn at start with timer reset.\n\nTimer: `timeLeft` seconds, starts at max(12, 30 - (level-1)*1.5). Decreases. If <=0 \u2192 lose life (drown-ish, \"time up\").\n\nHUD: draw score, high score, lives (as capybara icons or hearts), level, timer bar.\n\nRendering:\n- Water: gradient blue with animated sine wave lines.\n- Grass banks: green with tufts.\n- Logs: brown rounded rects with darker rings/ends.\n- Lily pads: green circles with notch (maybe on some logs? no).\n- Capybara: body ellipse brown, head, ears, eyes, nose, legs. Draw facing direction.\n\nLet me write drawCapybara(ctx, x, y, size, facing, t).\n\nCapybara: \n- body: ellipse rx=size*0.5, ry=size*0.36, color #a9743f (brownish)\n- head: ellipse at front, slightly smaller\n- ears: two small circles on top of head\n- eyes: black dots\n- nose: dark rounded rect\n- legs: small rounded rects at bottom\n\nLet's draw it top-down-ish? Since it's a top-down grid game, a top-down capybara would be more appropriate. Hmm. Frogger uses top-down view. Let's draw a top-down capybara: rounded rectangle body (oval), head at front with two ears, eyes, nose. That works.\n\nTop-down capybara facing up (default):\n- body: ellipse centered, rx = 0.42*T, ry = 0.5*T (taller than wide since facing up)\n- head: ellipse at top, rx=0.3*T, ry=0.26*T\n- ears: two small circles at top-left and top-right of head\n- eyes: two dots\n- nose: small dark ellipse at top of head\n- legs: 4 small ellipses at sides\n\nRotate based on facing direction (up/down/left/right). Use ctx.translate + rotate.\n\nFacing: default up. If moving left, rotate -90\u00b0, right +90\u00b0, down 180\u00b0.\n\nLet's implement with rotation: draw in local coords facing up, then rotate.\n\nGood.\n\nWater animation: draw base gradient, then a few horizontal sine wave strokes with alpha, offset by time.\n\nLet me also add ripples around logs.\n\nNow let's write the code.\n\n```js\n(() => {\n'use strict';\n\nconst canvas = document.getElementById('game');\nconst ctx = canvas.getContext('2d');\n\nconst TILE = 40, COLS = 12, ROWS = 13, HUD = 40;\nconst W = COLS*TILE, H = HUD + ROWS*TILE;\ncanvas.width = W; canvas.height = H;\n\nconst RIVER_TOP = 2, RIVER_BOT = 9; // rows 2..9 inclusive\nconst START_ROW = 12;\nconst GOAL_ROW = 1;\n\nfunction rowY(r){ return HUD + r*TILE; }\nfunction clamp(v,a,b){ return v<a?a:v>b?b:v; }\n```\n\nState machine: 'title', 'play', 'over', 'win'? Just title/play/over.\n\nLet me write the whole thing now.\n\nAudio module:\n\n```js\nconst Audio = (() => {\n  let ac = null, master = null, musicGain = null, sfxGain = null;\n  let musicTimer = null, musicStep = 0, nextNoteTime = 0;\n  let started = false;\n\n  function init(){\n    if (ac) return;\n    const AC = window.AudioContext || window.webkitAudioContext;\n    ac = new AC();\n    master = ac.createGain(); master.gain.value = 0.9; master.connect(ac.destination);\n    sfxGain = ac.createGain(); sfxGain.gain.value = 0.5; sfxGain.connect(master);\n    musicGain = ac.createGain(); musicGain.gain.value = 0.22; musicGain.connect(master);\n  }\n  function resume(){ if (ac && ac.state === 'suspended') ac.resume(); }\n  ...\n})();\n```\n\nNote: `Audio` is a global browser constructor name. Use `Snd` instead.\n\nTone helper:\n```js\nfunction tone(freq, dur, type, gain, when, dest){\n  const t = when ?? ac.currentTime;\n  const o = ac.createOscillator();\n  const g = ac.createGain();\n  o.type = type; o.frequency.setValueAtTime(freq, t);\n  g.gain.setValueAtTime(0, t);\n  g.gain.linearRampToValueAtTime(gain, t+0.01);\n  g.gain.exponentialRampToValueAtTime(0.0001, t+dur);\n  o.connect(g); g.connect(dest||sfxGain);\n  o.start(t); o.stop(t+dur+0.02);\n}\n```\n\nNoise helper for splash:\n```js\nfunction noise(dur, gain, when){\n  const t = when ?? ac.currentTime;\n  const len = Math.floor(ac.sampleRate*dur);\n  const buf = ac.createBuffer(1, len, ac.sampleRate);\n  const d = buf.getChannelData(0);\n  for (let i=0;i<len;i++) d[i] = (Math.random()*2-1) * (1 - i/len);\n  const src = ac.createBufferSource(); src.buffer = buf;\n  const f = ac.createBiquadFilter(); f.type='lowpass'; f.frequency.setValueAtTime(1800,t); f.frequency.exponentialRampToValueAtTime(300,t+dur);\n  const g = ac.createGain(); g.gain.setValueAtTime(gain,t); g.gain.exponentialRampToValueAtTime(0.0001,t+dur);\n  src.connect(f); f.connect(g); g.connect(sfxGain);\n  src.start(t); src.stop(t+dur);\n}\n```\n\nSFX:\n- hop: tone(520,0.09,'square',0.18) then tone(760,0.07,'square',0.12, t+0.05). Actually a quick \"boing\": frequency ramp.\n- splash: noise(0.5, 0.5) + low tone.\n- score: arpeggio [523,659,784,1047] triangle.\n- gameover: [440,392,330,262] descending sawtooth.\n- levelup maybe same as score.\n\nMusic scheduler:\n```js\nconst MEL = [76,null,79,null,81,null,79,null,76,null,74,null,72,null,74,null];\nconst BASS = [40,null,40,null,45,null,45,null,43,null,43,null,38,null,38,null];\nconst STEP = 0.28; // seconds per step\n```\nHmm, 16 steps * 0.28 = 4.48s loop.\n\nScheduler:\n```js\nfunction scheduler(){\n  if (!ac) return;\n  while (nextNoteTime < ac.currentTime + 0.15){\n    const i = musicStep % 16;\n    const m = MEL[i];\n    if (m != null) tone(midi(m), 0.5, 'triangle', 0.16, nextNoteTime, musicGain);\n    const b = BASS[i];\n    if (b != null) tone(midi(b), 0.6, 'sine', 0.3, nextNoteTime, musicGain);\n    // soft hat\n    nextNoteTime += STEP;\n    musicStep++;\n  }\n}\n```\nStart: `nextNoteTime = ac.currentTime + 0.1; musicStep=0; musicTimer = setInterval(scheduler, 40);`\n\nStop: clearInterval.\n\nAlso add a gentle pad chord every 4 steps? Keep simple.\n\nLet me add a soft \"water\" noise loop? Skip.\n\nNow the game.\n\n```js\nconst state = {\n  mode: 'title',\n  score: 0,\n  high: +(localStorage.getItem('capybaraHigh')||0),\n  lives: 3,\n  level: 1,\n  timeLeft: 30,\n  timeMax: 30,\n  t: 0,\n  flash: 0,\n  msg: '',\n};\n```\n\nLanes:\n```js\nlet lanes = [];\nfunction makeLanes(){\n  lanes = [];\n  const dirs = [1,-1,1,-1,1,-1,1,-1];\n  for (let i=0;i<8;i++){\n    const row = RIVER_TOP + i;\n    const dir = dirs[i];\n    const speed = 45 + Math.random()*45; // base\n    const wTiles = 2 + Math.floor(Math.random()*3); // 2..4\n    const w = wTiles*TILE;\n    const gap = 100 + Math.random()*70;\n    const n = Math.ceil((W + w + gap) / (w + gap));\n    const P = n*(w+gap);\n    const logs = [];\n    for (let k=0;k<n;k++) logs.push({ x: k*(w+gap) - Math.random()*40, w });\n    lanes.push({ row, dir, speed, w, gap, P, logs, baseSpeed: speed });\n  }\n}\n```\n\nHmm, random offsets per log break the even spacing. Let's use a single lane offset: `const off = Math.random()*P;` and logs at `(k*(w+gap) + off) % P`. But then wrap logic: x in [0,P). When dir>0, x increases; if x > W, we want it to wrap to x - P. But if x is in [0,P) and P > W, then a log at x in (W, P) is off-screen right. That's fine \u2014 it's \"waiting\". When x > P... hmm, we need x to stay in [0,P). Let's do: x += v*dt; if (x >= P) x -= P; if (x < 0) x += P. And logs are drawn at x, and also at x - P? No \u2014 since P > W + w, a log at x near P is off screen right, and there's no log at x-P (negative). So the visible pattern: logs at positions p_k = (off + k*(w+gap)) mod P. As they move right, each wraps from P to 0. Since P > W + w, when a log wraps to 0, the previous log is at P - (w+gap) which is > W (off screen right) \u2014 wait, is it? P - (w+gap) vs W: P = n*(w+g) >= W + w + g, so P - (w+g) >= W + w + g - w - g = W. So yes, >= W, off screen. Good, no overlap.\n\nBut careful: the log at x=0 has width w, so it spans [0,w]. The log at P-(w+g) spans [P-w-g, P-g]. Since P-w-g >= W, it's off screen. Good.\n\nSo wrap: `x = ((x % P) + P) % P`. Simple.\n\nBut then when a log wraps from P-\u03b5 to 0, the player riding it teleports from x\u2248P to 0 \u2014 that's a jump of P which is off-screen anyway. But the player would be off-screen at x\u2248P... Actually the player riding a log at x\u2248P is off-screen (x > W), so they'd have drowned already. Fine. But to be safe, when the log wraps and player is riding, set player.x += (newX - oldX) which is -P, teleporting them. They'd already be dead though. Let's just handle it.\n\nActually, better: only wrap when the log is fully off-screen. `if (dir>0 && x > W + 10) x -= P;` Hmm but then x could exceed P. Let's just use modulo and accept.\n\nHmm, with modulo, a log moving right at x = P-1 wraps to 0. At that moment it's off-screen right (P-1 > W). Fine.\n\nFor dir<0: x decreases, wraps from 0 to P-1 (off-screen right). Also fine.\n\nOK.\n\nNow, difficulty scaling: `lane.speed = lane.baseSpeed * (1 + 0.09*(level-1))`, capped at like 3x.\n\nLet me store baseSpeed and recompute on level change.\n\nPlayer:\n```js\nconst player = { col:5, row:START_ROW, x:0, y:0, fromX:0, fromY:0, toX:0, toY:0, hopT:0, facing:'up', riding:null, alive:true, squash:0 };\n```\n\nresetPlayer():\n```js\nplayer.col = 5; player.row = START_ROW;\nplayer.x = player.col*TILE + TILE/2;\nplayer.y = rowY(player.row) + TILE/2;\nplayer.fromX=player.x; player.fromY=player.y; player.toX=player.x; player.toY=player.y;\nplayer.hopT=0; player.riding=null; player.facing='up'; player.alive=true;\n```\n\nHOP_DUR = 0.13.\n\nUpdate:\n```js\nfunction update(dt){\n  state.t += dt;\n  if (state.mode !== 'play') return;\n  \n  // timer\n  state.timeLeft -= dt;\n  if (state.timeLeft <= 0){ state.timeLeft = 0; loseLife('time'); return; }\n  \n  // lanes\n  for (const lane of lanes){\n    for (const log of lane.logs){\n      const oldX = log.x;\n      log.x += lane.speed * lane.dir * dt;\n      if (log.x > lane.P) log.x -= lane.P;\n      if (log.x < 0) log.x += lane.P;\n      if (player.riding === log) player.x += log.x - oldX;\n    }\n  }\n  \n  // hop animation\n  if (player.hopT > 0){\n    player.hopT -= dt;\n    const k = 1 - Math.max(0, player.hopT)/HOP_DUR;\n    const e = k; // ease\n    player.x = player.fromX + (player.toX - player.fromX)*e;\n    player.y = player.fromY + (player.toY - player.fromY)*e;\n    if (player.hopT <= 0){\n      player.hopT = 0;\n      player.x = player.toX; player.y = player.toY;\n      onHopEnd();\n    }\n  } else {\n    // riding\n    if (player.riding){\n      // check still on log\n      if (!onAnyLog(player.x, player.row)) { player.riding = null; }\n    }\n    if (isRiverRow(player.row)){\n      const log = logUnder(player.x, player.row);\n      if (log){ player.riding = log; }\n      else { drown(); return; }\n    } else {\n      player.riding = null;\n    }\n    // off screen\n    if (player.x < -TILE*0.5 || player.x > W + TILE*0.5) { drown(); return; }\n  }\n}\n```\n\nHmm, careful: when riding, player.x is updated by the log. Then we check logUnder. If the player is still on the log, riding stays. If not (shouldn't happen unless wrap), drown.\n\nWait, there's an issue: `player.riding` is set to the log, and then in the next frame the log moves and player.x moves with it. Then logUnder(player.x) should return the same log. Good.\n\nBut when the player hops onto a log, at hop end we set riding. Let's do onHopEnd:\n```js\nfunction onHopEnd(){\n  if (isRiverRow(player.row)){\n    const log = logUnder(player.x, player.row);\n    if (log) player.riding = log;\n    else drown();\n  } else {\n    player.riding = null;\n    if (player.row <= GOAL_ROW) success();\n  }\n}\n```\n\nHmm, but the goal check: player.row <= 1. Let's make GOAL_ROW = 1 and check `player.row <= 1`.\n\nWait, but rows 0 and 1 are the top bank. If the player reaches row 1, success. Let's just check `player.row <= 1`.\n\nActually let's make the top bank rows 0-1 and success when row <= 1. Fine.\n\nlogUnder(x, row): find lane with lane.row === row, then find log where x >= log.x - TILE*0.35 && x <= log.x + log.w + TILE*0.35. Hmm, use a tolerance so the capybara's body can overhang a bit. Let's use tolerance of TILE*0.3.\n\nActually for fairness, use the capybara's center with a small tolerance: `x > log.x - 8 && x < log.x + log.w + 8`.\n\nLet's use tolerance 10.\n\ndrown():\n```js\nfunction drown(){\n  if (state.mode !== 'play') return;\n  player.alive = false;\n  player.riding = null;\n  Snd.splash();\n  state.lives--;\n  state.flash = 0.5;\n  if (state.lives <= 0){ gameOver(); }\n  else { respawn(); }\n}\n```\n\nHmm, but we want a brief death animation. Let's add a `dying` state with a timer. Simpler: immediately respawn but flash. Let's add a short pause: set state.mode='dying', deathTimer=0.9, then respawn.\n\nLet's do that for polish.\n\n```js\nfunction drown(){\n  if (state.mode !== 'play') return;\n  state.mode = 'dying';\n  state.deathT = 0.9;\n  state.deathReason = 'splash';\n  player.riding = null;\n  Snd.splash();\n  state.lives--;\n}\n```\nThen in update, if mode==='dying': deathT -= dt; if <=0: if lives<=0 gameOver() else { respawn(); state.mode='play'; }\n\nrespawn(): resetPlayer(); state.timeLeft = state.timeMax;\n\nsuccess():\n```js\nfunction success(){\n  const bonus = Math.round(state.timeLeft * 5);\n  state.score += 100 + state.level*10 + bonus;\n  state.level++;\n  state.timeMax = Math.max(12, 30 - (state.level-1)*1.5);\n  state.timeLeft = state.timeMax;\n  applyDifficulty();\n  Snd.score();\n  state.flash = 0.4;\n  state.msg = 'CROSSED! +' + (100 + ...);\n  state.msgT = 1.2;\n  resetPlayer();\n}\n```\n\nWait, level increments before computing timeMax \u2014 fine.\n\napplyDifficulty(): for each lane, lane.speed = min(lane.baseSpeed * (1 + 0.09*(level-1)), lane.baseSpeed*2.6).\n\nAlso maybe reduce log widths at higher levels? Skip.\n\ngameOver():\n```js\nfunction gameOver(){\n  state.mode = 'over';\n  if (state.score > state.high){ state.high = state.score; localStorage.setItem('capybaraHigh', String(state.high)); state.newHigh = true; }\n  Snd.gameOver();\n  Snd.stopMusic();\n}\n```\n\nHmm, should music stop on game over? Maybe keep it but lower. Let's stop it and play the game over jingle. Then on restart, start music again.\n\nActually, let's keep music playing throughout (it's ambient) and just play the jingle over it. Simpler and nicer. Hmm, but the jingle might clash. Let's duck the music: set musicGain to 0.06 during game over, restore on restart. Eh, let's just stop music on game over and restart it on new game. Clean.\n\nInput handling:\n\n```js\nwindow.addEventListener('keydown', e => {\n  const k = e.key;\n  if (['ArrowUp','ArrowDown','ArrowLeft','ArrowRight',' '].includes(k)) e.preventDefault();\n  Snd.unlock();\n  if (state.mode === 'title'){\n    if (k === ' ' || k === 'Enter') startGame();\n    return;\n  }\n  if (state.mode === 'over'){\n    if (k === ' ' || k === 'Enter' || k === 'r' || k === 'R') startGame();\n    return;\n  }\n  if (state.mode !== 'play') return;\n  if (k === 'ArrowUp' || k === 'w' || k === 'W') tryMove(0,-1);\n  else if (k === 'ArrowDown' || k === 's' || k === 'S') tryMove(0,1);\n  else if (k === 'ArrowLeft' || k === 'a' || k === 'A') tryMove(-1,0);\n  else if (k === 'ArrowRight' || k === 'd' || k === 'D') tryMove(1,0);\n});\n```\n\nAlso 'p' to pause? Skip.\n\nTouch: swipe on canvas.\n\n```js\nlet touchStart = null;\ncanvas.addEventListener('touchstart', e => { Snd.unlock(); const t = e.changedTouches[0]; touchStart = {x:t.clientX, y:t.clientY, time:performance.now()}; e.preventDefault(); }, {passive:false});\ncanvas.addEventListener('touchend', e => {\n  if (!touchStart) return;\n  const t = e.changedTouches[0];\n  const dx = t.clientX - touchStart.x, dy = t.clientY - touchStart.y;\n  const adx = Math.abs(dx), ady = Math.abs(dy);\n  if (state.mode === 'title' || state.mode === 'over'){ startGame(); touchStart=null; return; }\n  if (Math.max(adx,ady) < 20){ // tap\n    // tap = move up? \n  } else if (adx > ady) tryMove(dx>0?1:-1, 0);\n  else tryMove(0, dy>0?1:-1);\n  touchStart = null;\n  e.preventDefault();\n}, {passive:false});\n```\n\nAlso click on canvas to start.\n\nNow rendering.\n\ndrawTitle(): draw the game background (water + banks) with a big title, \"Press SPACE / Click to Start\", controls, high score.\n\nLet me draw the playfield always (as background), then overlay title/over screens.\n\ndraw():\n```js\nfunction draw(){\n  ctx.clearRect(0,0,W,H);\n  drawBanks();\n  drawWater();\n  drawLogs();\n  drawPlayer();\n  drawHUD();\n  if (state.mode === 'title') drawTitle();\n  if (state.mode === 'over') drawOver();\n  if (state.flash > 0) { ctx.fillStyle = `rgba(255,255,255,${state.flash*0.5})`; ctx.fillRect(0,0,W,H); }\n}\n```\n\nHmm, flash should be drawn before overlays maybe. Fine.\n\ndrawBanks: \n- top bank: rows 0-1 \u2192 rect(0, rowY(0), W, 2*TILE) green\n- bottom bank: rows 10-12 \u2192 rect(0, rowY(10), W, 3*TILE) green\n- Add darker green edge lines and grass tufts.\n\ndrawWater: rows 2..9 \u2192 rect(0, rowY(2), W, 8*TILE). Gradient from #2a6f97 to #1b4f72. Then animated wave lines.\n\nLet's do:\n```js\nconst g = ctx.createLinearGradient(0, rowY(2), 0, rowY(10));\ng.addColorStop(0,'#2e86ab'); g.addColorStop(0.5,'#1f6f96'); g.addColorStop(1,'#175a7a');\n```\nThen wave lines: for each of ~10 lines, draw a sine path with alpha 0.08 white, offset by time.\n\nAlso add some sparkles.\n\ndrawLogs: for each lane, for each log, draw a rounded rect with wood color, plus end rings (ellipses) and a couple of grain lines. Also draw a subtle shadow.\n\nLog color: #8b5a2b with darker #6b4423 ends.\n\nLet's draw:\n```js\nfunction roundRect(x,y,w,h,r){ ... }\n```\n\nLog: roundRect(log.x, rowY(lane.row)+6, log.w, TILE-12, 10) fill #9c6b3f, stroke #6b4423. Then draw 2-3 vertical lines for grain, and ellipse at each end.\n\nActually for a top-down log, draw an ellipse-ish rounded rect. Add darker ellipse at the left end (cut end) with rings.\n\nLet's do: fill rounded rect; then at x+6 draw ellipse (rx=5, ry=(TILE-12)/2) darker with a lighter inner ellipse. Same at right end.\n\nGood enough.\n\ndrawPlayer: if alive, draw capybara at (player.x, player.y).\n\nCapybara drawing (facing up in local coords, size ~ TILE):\n```js\nfunction drawCapybara(x, y, s, facing, t){\n  ctx.save();\n  ctx.translate(x,y);\n  const ang = {up:0, right:Math.PI/2, down:Math.PI, left:-Math.PI/2}[facing] || 0;\n  ctx.rotate(ang);\n  // shadow\n  ctx.fillStyle='rgba(0,0,0,0.18)';\n  ctx.beginPath(); ctx.ellipse(0, s*0.06, s*0.42, s*0.5, 0, 0, Math.PI*2); ctx.fill();\n  // legs\n  ctx.fillStyle='#7a5230';\n  const legY = [ -s*0.18, s*0.18 ];\n  for (const ly of legY){\n    ctx.beginPath(); ctx.ellipse(-s*0.34, ly, s*0.11, s*0.09, 0,0,Math.PI*2); ctx.fill();\n    ctx.beginPath(); ctx.ellipse( s*0.34, ly, s*0.11, s*0.09, 0,0,Math.PI*2); ctx.fill();\n  }\n  // body\n  ctx.fillStyle='#a9743f';\n  ctx.beginPath(); ctx.ellipse(0, 0, s*0.36, s*0.46, 0,0,Math.PI*2); ctx.fill();\n  // body highlight\n  ctx.fillStyle='rgba(255,255,255,0.12)';\n  ctx.beginPath(); ctx.ellipse(-s*0.1, -s*0.05, s*0.2, s*0.3, 0,0,Math.PI*2); ctx.fill();\n  // head\n  ctx.fillStyle='#b07c46';\n  ctx.beginPath(); ctx.ellipse(0, -s*0.42, s*0.28, s*0.24, 0,0,Math.PI*2); ctx.fill();\n  // ears\n  ctx.fillStyle='#8a5c33';\n  ctx.beginPath(); ctx.ellipse(-s*0.2, -s*0.58, s*0.09, s*0.08, 0,0,Math.PI*2); ctx.fill();\n  ctx.beginPath(); ctx.ellipse( s*0.2, -s*0.58, s*0.09, s*0.08, 0,0,Math.PI*2); ctx.fill();\n  // eyes\n  ctx.fillStyle='#2b1a10';\n  ctx.beginPath(); ctx.arc(-s*0.12, -s*0.46, s*0.045, 0, Math.PI*2); ctx.fill();\n  ctx.beginPath(); ctx.arc( s*0.12, -s*0.46, s*0.045, 0, Math.PI*2); ctx.fill();\n  // nose\n  ctx.fillStyle='#4a2f1c';\n  ctx.beginPath(); ctx.ellipse(0, -s*0.62, s*0.1, s*0.07, 0,0,Math.PI*2); ctx.fill();\n  ctx.restore();\n}\n```\n\nHmm, the head at -s*0.42 with ry 0.24 spans -0.66 to -0.18. Nose at -0.62. Ears at -0.58. OK.\n\nWait, the body ellipse ry = 0.46 spans -0.46..0.46, and the head is at -0.42 which overlaps. Good.\n\nTotal height ~ from -0.66 to 0.46 = 1.12*s. With s = TILE = 40, that's 45px, slightly bigger than the tile. Let's use s = TILE*0.92 = 36.8. Fine.\n\nActually let's use s = 34 to fit nicely.\n\nHmm, let me reconsider: the capybara should be recognizable. Let's keep s = TILE*0.9 = 36.\n\ndrawHUD: \n- Top strip: dark translucent bar with score, high, level, lives.\n- Timer bar at the bottom of the HUD or as a vertical bar on the side.\n\nLet's do: HUD strip 40px tall at top with:\n- Left: \"SCORE 1234\"\n- Center: \"LV 3\"\n- Right: \"HI 5678\"\n- Lives: small capybara icons? Let's draw hearts or small capybara heads. Let's draw small capybara icons at the right.\n\nHmm, space. Let's do:\n- Row 1 (y 0..40): SCORE left, HI right, and lives as small icons in the middle-right.\n- Timer: a thin bar at the very top (y 0..4) or at the bottom of the playfield.\n\nLet's put the timer as a horizontal bar just below the HUD (y 40..46)? That overlaps the top bank. Hmm.\n\nAlternative: make the HUD 44px and put the timer bar inside it at the bottom.\n\nLet's restructure: HUD height 44. Inside:\n- y 0..30: text row\n- y 32..40: timer bar (full width minus margins)\n\nThen playfield starts at y=44. ROWS*TILE = 13*40 = 520. Total H = 564. Let's just set HUD=44 and H = 44+520 = 564.\n\nHmm, let me keep HUD=40 and put the timer bar at y 34..39. Text at y 8..30. OK.\n\nActually simpler: HUD = 44, text baseline at 20, timer bar at y=30, height 8, from x=8 to W-8.\n\nLet me set HUD = 44, H = 44 + 13*40 = 564.\n\nFine.\n\nLet me now also handle the \"msg\" popup (e.g., \"CROSSED! +150\").\n\nNow, the title screen: draw a semi-transparent dark overlay over the playfield, then the title text, subtitle, controls, high score, and a pulsing \"PRESS SPACE TO START\".\n\nGame over screen: overlay with \"GAME OVER\", final score, high score, \"PRESS SPACE TO RESTART\".\n\nLet's write the text with a nice font: `bold 40px \"Trebuchet MS\", system-ui, sans-serif`. Use a fallback.\n\nLet me now write everything out.\n\nOne more thing: the requestAnimationFrame loop with dt clamped.\n\n```js\nlet last = performance.now();\nfunction loop(now){\n  let dt = (now - last)/1000; last = now;\n  if (dt > 0.05) dt = 0.05;\n  update(dt);\n  draw();\n  requestAnimationFrame(loop);\n}\n```\n\nAlso `state.flash` decay and `state.msgT` decay in update (even when not playing? put at top of update).\n\nLet me write update:\n\n```js\nfunction update(dt){\n  state.t += dt;\n  if (state.flash > 0) state.flash = Math.max(0, state.flash - dt*2);\n  if (state.msgT > 0) state.msgT = Math.max(0, state.msgT - dt);\n  \n  if (state.mode === 'dying'){\n    state.deathT -= dt;\n    if (state.deathT <= 0){\n      if (state.lives <= 0) gameOver();\n      else { respawn(); state.mode='play'; }\n    }\n    return;\n  }\n  if (state.mode !== 'play') return;\n  ...\n}\n```\n\nWait, but during 'dying' we still want the logs to move? Not necessary. Let's freeze. Actually it looks nicer if the water keeps moving. Let's move the lanes during dying too. Let's restructure: move lanes always when mode is 'play' or 'dying'.\n\nLet me restructure:\n\n```js\nfunction update(dt){\n  state.t += dt;\n  ...\n  const active = (state.mode === 'play' || state.mode === 'dying');\n  if (active) updateLanes(dt);\n  \n  if (state.mode === 'dying'){ ... return; }\n  if (state.mode !== 'play') return;\n  updatePlayer(dt);\n  // timer\n  ...\n}\n```\n\nBut updateLanes moves the player if riding. During dying, player.riding is null. Fine.\n\nLet me write updateLanes separately.\n\nNow, the timer: decrement only in play mode.\n\nLet me write it all out now.\n\nAlso need `Snd.unlock()` on first gesture \u2014 call `Snd.init()` and `resume()`.\n\nstartGame():\n```js\nfunction startGame(){\n  Snd.init(); Snd.resume(); Snd.startMusic();\n  state.mode = 'play';\n  state.score = 0;\n  state.lives = 3;\n  state.level = 1;\n  state.timeMax = 30;\n  state.timeLeft = 30;\n  state.newHigh = false;\n  makeLanes();\n  applyDifficulty();\n  resetPlayer();\n  state.msg = ''; state.msgT = 0;\n}\n```\n\nWait, makeLanes randomizes each game. Good for replayability. But then the difficulty scaling uses baseSpeed. Fine.\n\nHmm, but should lanes be regenerated on each level? No, keep them, just speed up.\n\nLet me make sure `applyDifficulty` is called after makeLanes.\n\nNow let's write the code for real.\n\nAlso: prevent the page from scrolling on arrow keys \u2014 done via preventDefault.\n\nLet me also add a subtle \"current\" visual: arrows in the water? Skip.\n\nLet me write the file.\n\nOne more consideration: `logUnder` needs the lane. Let's build a map from row to lane.\n\n```js\nfunction laneAt(row){ return lanes.find(l => l.row === row); }\n```\n\nisRiverRow(row): row >= RIVER_TOP && row <= RIVER_BOT.\n\nLet me write it.\n\nAlso, for the goal: when the player reaches row <= 1, success. But the player might be at row 1 which is the top bank. Let's draw a \"goal\" area on the top bank \u2014 maybe a nice grassy area with flowers and a \"HOME\" sign. Let's draw some bushes/flowers.\n\nLet's also draw the top bank with a lighter green and some flowers.\n\nOK, writing now.\n\nFor the water waves, I'll draw:\n```js\nfunction drawWater(){\n  const y0 = rowY(RIVER_TOP), y1 = rowY(RIVER_BOT+1);\n  const g = ctx.createLinearGradient(0,y0,0,y1);\n  g.addColorStop(0,'#2b7fa8'); g.addColorStop(0.5,'#1e6b93'); g.addColorStop(1,'#155a7d');\n  ctx.fillStyle = g; ctx.fillRect(0,y0,W,y1-y0);\n  \n  // wave lines\n  ctx.save();\n  ctx.globalAlpha = 0.10;\n  ctx.strokeStyle = '#ffffff';\n  ctx.lineWidth = 2;\n  for (let i=0;i<14;i++){\n    const yy = y0 + 12 + i*((y1-y0-24)/13);\n    ctx.beginPath();\n    for (let x=0;x<=W;x+=8){\n      const off = Math.sin((x*0.03) + state.t*1.6 + i*0.9)*3;\n      if (x===0) ctx.moveTo(x, yy+off); else ctx.lineTo(x, yy+off);\n    }\n    ctx.stroke();\n  }\n  ctx.restore();\n  \n  // sparkles\n  ...\n}\n```\n\nGood.\n\nAlso add a subtle darkening at the river edges.\n\nLet me write the final code.\n\nFor the HUD lives, draw small capybara heads:\n```js\nfunction drawLifeIcon(x,y,s){\n  ctx.fillStyle='#b07c46';\n  ctx.beginPath(); ctx.ellipse(x,y,s*0.5,s*0.42,0,0,Math.PI*2); ctx.fill();\n  ctx.fillStyle='#8a5c33';\n  ctx.beginPath(); ctx.arc(x-s*0.34,y-s*0.3,s*0.16,0,Math.PI*2); ctx.fill();\n  ctx.beginPath(); ctx.arc(x+s*0.34,y-s*0.3,s*0.16,0,Math.PI*2); ctx.fill();\n  ctx.fillStyle='#2b1a10';\n  ctx.beginPath(); ctx.arc(x-s*0.18,y-s*0.05,s*0.08,0,Math.PI*2); ctx.fill();\n  ctx.beginPath(); ctx.arc(x+s*0.18,y-s*0.05,s*0.08,0,Math.PI*2); ctx.fill();\n  ctx.fillStyle='#4a2f1c';\n  ctx.beginPath(); ctx.ellipse(x,y+s*0.16,s*0.16,s*0.1,0,0,Math.PI*2); ctx.fill();\n}\n```\n\nOK.\n\nNow writing the full file.\n\nLet me be careful with the `Snd` module and the `tone` function referencing `ac` before init. Guard.\n\nLet me write:\n\n```js\nconst Snd = (function(){\n  let ac=null, master=null, sfxBus=null, musBus=null;\n  let musicTimer=null, step=0, nextT=0, musicOn=false;\n  const MEL = [76,null,79,null,81,null,79,null,76,null,74,null,72,null,74,null];\n  const BASS= [40,null,40,null,45,null,45,null,43,null,43,null,38,null,38,null];\n  const STEP = 0.27;\n  function midi(n){ return 440*Math.pow(2,(n-69)/12); }\n  function init(){\n    if (ac) return;\n    const AC = window.AudioContext||window.webkitAudioContext;\n    if (!AC) return;\n    ac = new AC();\n    master = ac.createGain(); master.gain.value = 0.85; master.connect(ac.destination);\n    sfxBus = ac.createGain(); sfxBus.gain.value = 0.55; sfxBus.connect(master);\n    musBus = ac.createGain(); musBus.gain.value = 0.0; musBus.connect(master);\n  }\n  function resume(){ if (ac && ac.state==='suspended') ac.resume(); }\n  function tone(freq,dur,type,gain,when,bus){\n    if (!ac) return;\n    const t = when==null?ac.currentTime:when;\n    const o = ac.createOscillator(), g = ac.createGain();\n    o.type=type; o.frequency.setValueAtTime(freq,t);\n    g.gain.setValueAtTime(0.0001,t);\n    g.gain.exponentialRampToValueAtTime(gain,t+0.012);\n    g.gain.exponentialRampToValueAtTime(0.0001,t+dur);\n    o.connect(g); g.connect(bus||sfxBus);\n    o.start(t); o.stop(t+dur+0.03);\n  }\n  ...\n})();\n```\n\nNote: exponentialRampToValueAtTime requires positive values. Using 0.0001 is fine.\n\nFor the music bus, I'll fade in with `musBus.gain.linearRampToValueAtTime(0.22, ac.currentTime+1)`.\n\nMusic scheduler:\n```js\nfunction scheduler(){\n  if (!ac || !musicOn) return;\n  while (nextT < ac.currentTime + 0.2){\n    const i = step % 16;\n    const m = MEL[i];\n    if (m!=null) tone(midi(m), 0.55, 'triangle', 0.14, nextT, musBus);\n    const b = BASS[i];\n    if (b!=null) tone(midi(b), 0.7, 'sine', 0.28, nextT, musBus);\n    if (i%4===0) tone(midi(m!=null?m:72)+12, 0.25, 'sine', 0.05, nextT, musBus);\n    nextT += STEP; step++;\n  }\n}\n```\n\nHmm, the last line adds a high sparkle. Fine.\n\nstartMusic:\n```js\nfunction startMusic(){\n  init(); if (!ac) return;\n  if (musicOn) return;\n  musicOn = true; step = 0; nextT = ac.currentTime + 0.15;\n  musBus.gain.cancelScheduledValues(ac.currentTime);\n  musBus.gain.setValueAtTime(0.0001, ac.currentTime);\n  musBus.gain.linearRampToValueAtTime(0.22, ac.currentTime+1.2);\n  musicTimer = setInterval(scheduler, 40);\n}\nfunction stopMusic(){\n  if (!ac) return;\n  musicOn = false;\n  if (musicTimer){ clearInterval(musicTimer); musicTimer=null; }\n  musBus.gain.cancelScheduledValues(ac.currentTime);\n  musBus.gain.setValueAtTime(musBus.gain.value, ac.currentTime);\n  musBus.gain.linearRampToValueAtTime(0.0001, ac.currentTime+0.4);\n}\n```\n\nCareful: `musBus.gain.value` after cancelScheduledValues \u2014 reading .value gives the current value. OK.\n\nSFX:\n```js\nfunction hop(){\n  if (!ac) return;\n  const t = ac.currentTime;\n  const o = ac.createOscillator(), g = ac.createGain();\n  o.type='square';\n  o.frequency.setValueAtTime(420,t);\n  o.frequency.exponentialRampToValueAtTime(880,t+0.08);\n  g.gain.setValueAtTime(0.0001,t);\n  g.gain.exponentialRampToValueAtTime(0.16,t+0.01);\n  g.gain.exponentialRampToValueAtTime(0.0001,t+0.12);\n  o.connect(g); g.connect(sfxBus); o.start(t); o.stop(t+0.14);\n}\nfunction splash(){\n  if (!ac) return;\n  const t = ac.currentTime;\n  const dur = 0.6;\n  const len = Math.floor(ac.sampleRate*dur);\n  const buf = ac.createBuffer(1,len,ac.sampleRate);\n  const d = buf.getChannelData(0);\n  for (let i=0;i<len;i++){ const k=i/len; d[i]=(Math.random()*2-1)*Math.pow(1-k,2); }\n  const src = ac.createBufferSource(); src.buffer=buf;\n  const f = ac.createBiquadFilter(); f.type='lowpass';\n  f.frequency.setValueAtTime(2200,t); f.frequency.exponentialRampToValueAtTime(250,t+dur);\n  const g = ac.createGain(); g.gain.setValueAtTime(0.5,t); g.gain.exponentialRampToValueAtTime(0.0001,t+dur);\n  src.connect(f); f.connect(g); g.connect(sfxBus); src.start(t); src.stop(t+dur);\n  // descending blip\n  tone(300,0.35,'sine',0.2,t+0.05);\n  tone(180,0.4,'sine',0.15,t+0.15);\n}\nfunction score(){\n  if (!ac) return;\n  const t = ac.currentTime;\n  [523.25,659.25,783.99,1046.5].forEach((f,i)=> tone(f,0.28,'triangle',0.18,t+i*0.08));\n}\nfunction gameOverSfx(){\n  if (!ac) return;\n  const t = ac.currentTime;\n  [392,349.23,293.66,220].forEach((f,i)=> tone(f,0.5,'sawtooth',0.14,t+i*0.18));\n}\n```\n\nHmm, sawtooth might be harsh. Use 'triangle' with lower gain. Let's use 'square' at low gain... I'll use 'triangle' 0.16.\n\nOK.\n\nNow let me write the whole file.\n\nAlso, I should handle the case where the AudioContext isn't available \u2014 guard everything.\n\nLet me write out the final HTML.\n\nFor the canvas scaling CSS:\n```css\nhtml,body{margin:0;height:100%;background:#0b1a24;overflow:hidden;}\nbody{display:flex;align-items:center;justify-content:center;}\ncanvas{\n  display:block;\n  background:#0b1a24;\n  box-shadow:0 0 40px rgba(0,0,0,0.7);\n  border-radius:8px;\n  max-width:100vw;\n  max-height:100vh;\n  width:auto;height:auto;\n  touch-action:none;\n}\n```\nHmm, with `width:auto;height:auto` and max-width/max-height, the canvas will use its intrinsic size (480x564) unless it exceeds the viewport. To make it scale up on large screens, use:\n```css\ncanvas{ width: min(100vw, calc(100vh * 480/564)); height: auto; }\n```\nThat scales it. Let's use that with aspect ratio.\n\nActually: `height: min(100vh, calc(100vw * 564/480)); width: auto;` \u2014 either works. Let's do:\n```css\ncanvas{\n  width: min(96vw, calc(96vh * 480 / 564));\n  height: auto;\n  ...\n}\n```\nGood.\n\nNow writing.\n\nLet me double check the row layout:\n- HUD = 44\n- rows 0..12, each 40px\n- row 0: y 44..84 (top bank)\n- row 1: y 84..124 (top bank)\n- rows 2..9: river, y 124..444\n- rows 10,11,12: bottom bank, y 444..564\n\nPlayer start row 12 \u2192 y center = 44 + 12*40 + 20 = 544. Good.\n\nGoal row 1 \u2192 y center = 44+40+20 = 104.\n\nRiver rows 2..9 \u2192 8 lanes. Good.\n\nNow, the player at row 12 (bottom bank) can move up to row 11, 10 (still bank), then row 9 (river). Good.\n\nLet's write.\n\nOne thing: when the player is on the bottom bank and moves up into the river, they need a log. Fine.\n\nAlso, the player shouldn't be able to move down past row 12. Clamped.\n\nLet me write the code.\n\nAlso add: pressing 'p' pauses? Skip.\n\nLet me write the final file now.\n\nFor the message popup, draw at center of the river area.\n\nLet me write.\n\nAlso I want a nice \"goal\" visual on the top bank: draw some bushes and a \"HOME\" area. Let's draw a few bushes (dark green circles) and flowers.\n\nLet me write drawBanks:\n\n```js\nfunction drawBanks(){\n  // top bank\n  const ty = rowY(0), th = 2*TILE;\n  let g = ctx.createLinearGradient(0,ty,0,ty+th);\n  g.addColorStop(0,'#4e9a4a'); g.addColorStop(1,'#3d7d3a');\n  ctx.fillStyle=g; ctx.fillRect(0,ty,W,th);\n  // bottom bank\n  const by = rowY(10), bh = 3*TILE;\n  g = ctx.createLinearGradient(0,by,0,by+bh);\n  g.addColorStop(0,'#3d7d3a'); g.addColorStop(1,'#4e9a4a');\n  ctx.fillStyle=g; ctx.fillRect(0,by,W,bh);\n  \n  // grass tufts\n  ctx.strokeStyle='rgba(255,255,255,0.10)'; ctx.lineWidth=2;\n  for (let i=0;i<60;i++){\n    const x = (i*97)%W, y = ty + 8 + ((i*53)%(th-16));\n    ctx.beginPath(); ctx.moveTo(x,y); ctx.lineTo(x+3,y-7); ctx.stroke();\n  }\n  for (let i=0;i<90;i++){\n    const x = (i*61)%W, y = by + 8 + ((i*37)%(bh-16));\n    ctx.beginPath(); ctx.moveTo(x,y); ctx.lineTo(x+3,y-7); ctx.stroke();\n  }\n  \n  // flowers on top bank\n  for (let i=0;i<10;i++){\n    const x = 20 + i*46, y = ty + 20 + ((i*29)%40);\n    ctx.fillStyle = ['#f2c14e','#e86a92','#f2f2f2'][i%3];\n    ctx.beginPath(); ctx.arc(x,y,3.5,0,Math.PI*2); ctx.fill();\n  }\n  \n  // edge lines\n  ctx.fillStyle='rgba(0,0,0,0.18)';\n  ctx.fillRect(0, ty+th-3, W, 3);\n  ctx.fillRect(0, by, W, 3);\n}\n```\n\nHmm, the flowers might overlap the player. It's fine.\n\nActually, the top bank is the goal \u2014 let's make it look inviting with a \"HOME\" text? Maybe draw a small wooden sign. Let's skip and just have flowers.\n\nNow let's write everything.\n\nLet me also handle the case where the player is drawn during 'dying' \u2014 draw a splash effect instead. Let's draw expanding rings at the player's last position.\n\nI'll store `state.deathX, state.deathY` on drown.\n\nOK, writing the final code now.\n\nLet me write it out completely and carefully.\n\n```html\n<!DOCTYPE html>\n<html lang=\"en\">\n<head>\n<meta charset=\"utf-8\">\n<meta name=\"viewport\" content=\"width=device-width, initial-scale=1, maximum-scale=1, user-scalable=no\">\n<title>Capybara Crossing</title>\n<style>\n  html,body{margin:0;padding:0;height:100%;background:#08131b;overflow:hidden;}\n  body{display:flex;align-items:center;justify-content:center;font-family:\"Trebuchet MS\",system-ui,sans-serif;}\n  canvas{\n    display:block;\n    width:min(96vw, calc(96vh * 480 / 564));\n    height:auto;\n    border-radius:10px;\n    box-shadow:0 10px 50px rgba(0,0,0,.75), 0 0 0 2px rgba(255,255,255,.06);\n    touch-action:none;\n    cursor:pointer;\n  }\n</style>\n</head>\n<body>\n<canvas id=\"game\" width=\"480\" height=\"564\"></canvas>\n<script>\n...\n</script>\n</body>\n</html>\n```\n\nNow the script.\n\nI'll write it in one go.\n\nLet me think about `applyDifficulty` and lane speed cap.\n\n```js\nfunction applyDifficulty(){\n  const mult = Math.min(1 + 0.10*(state.level-1), 2.4);\n  for (const lane of lanes) lane.speed = lane.baseSpeed * mult;\n}\n```\n\nAnd timeMax: `Math.max(12, 30 - (state.level-1)*1.6)`.\n\nHmm, at level 1: 30s. Level 12: 30-17.6=12.4. Level 13+: 12. OK.\n\nNow writing.\n\nAlso, I realize the player's `facing` should update on move.\n\nLet me finalize tryMove:\n\n```js\nfunction tryMove(dx, dy){\n  if (state.mode !== 'play' || player.hopT > 0) return;\n  const nc = clamp(player.col + dx, 0, COLS-1);\n  const nr = clamp(player.row + dy, 0, ROWS-1);\n  if (nc === player.col && nr === player.row) return;\n  player.col = nc; player.row = nr;\n  player.fromX = player.x; player.fromY = player.y;\n  player.toX = nc*TILE + TILE/2;\n  player.toY = rowY(nr) + TILE/2;\n  player.hopT = HOP_DUR;\n  if (dx > 0) player.facing='right'; else if (dx<0) player.facing='left';\n  else if (dy>0) player.facing='down'; else if (dy<0) player.facing='up';\n  player.riding = null;\n  Snd.hop();\n}\n```\n\nWait \u2014 setting `player.riding = null` when hopping off a log. But then during the hop, the player's x is interpolated from fromX to toX. That's fine.\n\nBut there's a subtlety: if the player hops from a log to another tile in the same river row, the target x is the grid center, which may not be on a log. Then at hop end, they drown. That's correct Frogger behavior.\n\nHmm, but actually in Frogger you can hop along a log and stay on it. With grid snapping, hopping right by one tile from a log moves you to the grid center, which might be off the log. That's a bit harsh but it's the classic behavior... Actually in classic Frogger, the frog moves in grid steps and the logs move continuously, so the frog's position relative to the log changes. Hopping along a log works if the log is long enough.\n\nSince our logs are 2-4 tiles wide, hopping one tile along a log usually keeps you on it. Fine.\n\nBut there's an issue: when the player is riding a log and hops, `fromX` is the current (non-grid) x. The hop interpolates to the grid center. Good.\n\nNow, during the hop, should we check drowning? No, only at hop end. Good.\n\nAlso, during the hop, the player's y is interpolated, so they visually move.\n\nEdge case: the player hops up from row 10 (bank) to row 9 (river) \u2014 at hop end, check for a log. If none, drown. Good.\n\nNow `onHopEnd` also handles the goal.\n\nLet me also make sure that when the player is on the bottom bank and the timer runs out, they lose a life. Fine.\n\nLet me write `respawn`:\n```js\nfunction respawn(){\n  resetPlayer();\n  state.timeLeft = state.timeMax;\n}\n```\n\nAnd in the dying handler, after respawn, set mode='play'.\n\nNow, `drown()` sets mode='dying' and decrements lives. Then in update, when deathT <= 0: if lives <= 0 \u2192 gameOver() else respawn + mode='play'.\n\nBut gameOver() sets mode='over'. Good.\n\nLet me write the draw for the dying state: draw expanding rings at deathX, deathY.\n\n```js\nif (state.mode === 'dying'){\n  const k = 1 - state.deathT/0.9;\n  ctx.save();\n  ctx.strokeStyle = `rgba(255,255,255,${0.7*(1-k)})`;\n  ctx.lineWidth = 3;\n  for (let i=0;i<3;i++){\n    const r = 8 + k*40 + i*10;\n    ctx.beginPath(); ctx.arc(state.deathX, state.deathY, r, 0, Math.PI*2); ctx.stroke();\n  }\n  ctx.restore();\n}\n```\n\nAnd don't draw the player during dying.\n\nOK. Writing now for real.\n\nLet me also add a small \"ripple\" trail behind logs? 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