(function(){
'use strict';
/* ============================================================
   TRENCH DEFENSE — 50 WAVES
   Hold the line: infantry, tanks and landships cross the snow.
   ============================================================ */
const cv = document.getElementById('trenchgame');
const ctx = cv.getContext('2d');

// ---------- Layout ----------
const W = 960, H = 800, HUD_H = 64;
const FIELD_Y = HUD_H;                 // 64
const SHOP_Y = 680;
const FIELD_H = SHOP_Y - FIELD_Y;      // 616
const ENEMY_TRENCH_Y = FIELD_Y + 30;   // 94 (center line of enemy trench)
const PLAYER_TRENCH_Y = SHOP_Y - 30;   // 650
const LEAK_Y = SHOP_Y - 28;            // 652 — enemies crossing this line hit your trench
const PLACE_MIN_Y = FIELD_Y + 56;      // no building inside the enemy trench band

// ---------- Defense definitions ----------
const DEF_DEFS = {
  mg:     { name:'MG Nest', cost:60, color:'#7a7f6a', desc:'Rapid fire',
    lv:[ {dmg:4,  rate:6,   range:135, cost:0},
         {dmg:6,  rate:7,   range:145, cost:55},
         {dmg:10, rate:8.5, range:155, cost:100} ] },
  sniper: { name:'Sniper', cost:110, color:'#8a7a5a', desc:'Long range marksman',
    lv:[ {dmg:45,  rate:0.55, range:265, cost:0},
         {dmg:85,  rate:0.60, range:290, cost:90},
         {dmg:150, rate:0.65, range:315, cost:160} ] },
  mortar: { name:'Mortar', cost:130, color:'#6a7078', desc:'Splash shells',
    lv:[ {dmg:32, rate:0.50, range:245, splash:58, cost:0},
         {dmg:55, rate:0.55, range:255, splash:68, cost:110},
         {dmg:95, rate:0.60, range:270, splash:80, cost:185} ] },
  wire:   { name:'Barbed Wire', cost:40, color:'#9aa0a6', desc:'Slows 45% - wears out',
            radius:36, slow:0.45, dur:40 },
  mine:   { name:'Mine', cost:50, color:'#5a4a3a', desc:'One big boom',
            dmg:130, splash:62, trigger:26 },
};
const SHOP_ORDER = ['mg','sniper','mortar','wire','mine'];

// ---------- Enemy kinds ----------
const KIND = {
  infantry:{ hp:1,    sp:1,    r:7,  rw:1,  leak:1 },
  runner:  { hp:0.55, sp:1.55, r:6,  rw:1,  leak:1 },
  officer: { hp:1.7,  sp:1.12, r:7,  rw:2,  leak:1 },
  mgteam:  { hp:2.6,  sp:0.70, r:9,  rw:2,  leak:1 },
  tank:    { hp:9,    sp:0.45, r:20, rw:6,  leak:3 },
  mini:    { hp:6,    sp:0.60, r:16, rw:10, leak:3 },
  boss:    { hp:14,   sp:0.40, r:27, rw:25, leak:8 },
};
const FOOT_KINDS = { infantry:1, runner:1, officer:1, mgteam:1 };

// ---------- Game state ----------
let state = 'menu';           // menu | play | victory | defeat
let wave = 1, gold = 250, lives = 20, score = 0;
let defs = [], enemies = [], queue = [];
let shells = [], artShells = [], tracers = [], muzzle = [];
let smoke = [], flashes = [], texts = [], decals = [], scorch = [];
let waveActive = false, spawnT = 0, spawnInterval = 0.8;
let speed = 1, paused = false, time = 0;
let shopSel = null, defSel = null, mouse = { x:0, y:0, in:false };
let artCD = 0, artArmed = false;
let leakFlash = 0, shakeT = 0, denyT = 0, denyMsg = '';
const SAVE_KEY = 'trench_save_v1';

// Wikibusiness logo (menu + HUD)
const LOGO_URL = 'https://wikibusiness.biz/wp-content/uploads/2026/10/wikibusiness-logo-game.png';
const logoImg = new Image();
let logoReady = false;
logoImg.onload = function(){ logoReady = true; };
logoImg.src = LOGO_URL;

// ---------- Audio (tiny synth, no assets) ----------
let AC = null, muted = false;
const lastSfx = {};
function sfx(kind){
  if(muted) return;
  const now = performance.now();
  if(lastSfx[kind] && now - lastSfx[kind] < 70) return;
  lastSfx[kind] = now;
  try{
    AC = AC || new (window.AudioContext || window.webkitAudioContext)();
    if(AC.state === 'suspended') AC.resume();
    const o = AC.createOscillator(), g = AC.createGain();
    const P = { gun:[720,0.05,'square',0.014], sniper:[190,0.20,'sawtooth',0.030],
      mortar:[95,0.30,'sine',0.050], boom:[65,0.50,'sine',0.085],
      whistle:[1500,0.55,'sine',0.020], kill:[420,0.08,'triangle',0.028],
      place:[560,0.08,'square',0.026], evolve:[440,0.30,'square',0.032],
      leak:[130,0.40,'sawtooth',0.055], coin:[1250,0.07,'sine',0.026],
      click:[880,0.05,'square',0.020], start:[300,0.25,'square',0.036] }[kind] || [440,0.1,'square',0.03];
    o.type = P[2]; o.frequency.setValueAtTime(P[0], AC.currentTime);
    if(kind === 'whistle') o.frequency.exponentialRampToValueAtTime(240, AC.currentTime + P[1]);
    if(kind === 'kill' || kind === 'leak' || kind === 'boom') o.frequency.exponentialRampToValueAtTime(55, AC.currentTime + P[1]);
    if(kind === 'evolve') o.frequency.exponentialRampToValueAtTime(880, AC.currentTime + P[1]);
    g.gain.setValueAtTime(P[3], AC.currentTime);
    g.gain.exponentialRampToValueAtTime(0.0001, AC.currentTime + P[1]);
    o.connect(g); g.connect(AC.destination);
    o.start(); o.stop(AC.currentTime + P[1] + 0.02);
  }catch(e){}
}

// ---------- Save / load ----------
function saveGame(){
  if(state !== 'play' || waveActive) return;
  try{
    localStorage.setItem(SAVE_KEY, JSON.stringify({
      wave, gold, lives, score,
      defs: defs.map(d => ({ type:d.type, x:d.x, y:d.y, lvl:d.lvl, invested:d.invested,
                             integrity: d.type === 'wire' ? d.integrity : undefined }))
    }));
  }catch(e){}
}
function loadGame(){
  try{
    const s = JSON.parse(localStorage.getItem(SAVE_KEY));
    if(!s || !s.wave || s.wave > 50) return false;
    wave = s.wave; gold = s.gold; lives = s.lives; score = s.score || 0; defs = [];
    for(const sd of (s.defs || [])){
      if(!DEF_DEFS[sd.type]) continue;
      defs.push(mkDef(sd.type, sd.x, sd.y, sd.lvl || 0, sd.invested || DEF_DEFS[sd.type].cost,
                      sd.integrity != null ? sd.integrity : DEF_DEFS.wire.dur));
    }
    return true;
  }catch(e){ return false; }
}
function hasSave(){
  try{ const s = JSON.parse(localStorage.getItem(SAVE_KEY)); return !!(s && s.wave && s.wave <= 50); }
  catch(e){ return false; }
}
function clearSave(){ try{ localStorage.removeItem(SAVE_KEY); }catch(e){} }

// ---------- Helpers ----------
function fmt(n){ return Math.floor(n).toLocaleString('en-US'); }
function rr(x,y,w,h,r){
  ctx.beginPath();
  ctx.moveTo(x+r,y); ctx.arcTo(x+w,y,x+w,y+h,r); ctx.arcTo(x+w,y+h,x,y+h,r);
  ctx.arcTo(x,y+h,x,y,r); ctx.arcTo(x,y,x+w,y,r); ctx.closePath();
}
function addText(x,y,text,color,size){
  texts.push({ x, y, text, color: color || '#ffe27a', size: size || 15, ttl: 1.1 });
}
function deny(msg){ denyT = 1.1; denyMsg = msg; shakeT = Math.max(shakeT, 0.18); sfx('leak'); }
function mkSmoke(x,y,r,life){
  return { x, y, r, vx:(Math.random()-0.5)*7, vy:-9-Math.random()*9, ttl:life, max:life };
}
function defStats(d){ return DEF_DEFS[d.type].lv[d.lvl]; }
function mkDef(type,x,y,lvl,invested,integrity){
  const d = { type, x, y, lvl: lvl || 0, invested: invested != null ? invested : DEF_DEFS[type].cost,
              cd:0, angle:-Math.PI/2, target:null };
  if(type === 'wire'){ d.integrity = integrity != null ? integrity : DEF_DEFS.wire.dur; d.inside = new Set(); }
  return d;
}

// ---------- Static battlefield decoration ----------
const speckles = [], craters = [], trees = [], wrecks = [], flakes = [];
(function genDecor(){
  for(let i=0;i<340;i++) speckles.push({ x:Math.random()*W, y:FIELD_Y+Math.random()*FIELD_H,
    r:0.6+Math.random()*1.6, a:0.05+Math.random()*0.10 });
  for(let i=0;i<26;i++) craters.push({ x:30+Math.random()*(W-60), y:FIELD_Y+76+Math.random()*(FIELD_H-150),
    r:10+Math.random()*20 });
  for(let i=0;i<6;i++) trees.push({ x:40+Math.random()*(W-80), y:FIELD_Y+90+Math.random()*(FIELD_H-170),
    s:0.8+Math.random()*0.7, lean:(Math.random()-0.5)*0.5 });
  for(let i=0;i<3;i++) wrecks.push({ x:70+Math.random()*(W-140), y:FIELD_Y+100+Math.random()*(FIELD_H-190),
    rot:(Math.random()-0.5)*1.1 });
  for(let i=0;i<130;i++) flakes.push({ x:Math.random()*W, y:Math.random()*H,
    r:0.8+Math.random()*1.9, sp:14+Math.random()*26, ph:Math.random()*6.28 });
})();
function trenchPts(baseY){
  const pts = [];
  for(let x=-40,i=0; x<=W+40; x+=74,i++) pts.push({ x, y: baseY + (i%2 ? 11 : -7) });
  return pts;
}

// ================= WAVES =================
function waveSpec(n){
  return { n,
    count: Math.min(8 + Math.floor(n*1.4), 110),
    hp: Math.round(20*Math.pow(1.08,n) + 5*n),
    speed: Math.min(36 + n*0.9, 78),
    reward: 5 + n,
    interval: Math.max(0.26, 0.85 - n*0.007) };
}
function pickKind(n){
  const r = Math.random();
  if(n >= 6  && r < 0.10) return 'tank';
  if(n >= 8  && r < 0.25) return 'mgteam';
  if(n >= 12 && r < 0.33) return 'officer';
  if(n >= 3  && r < 0.55) return 'runner';
  return 'infantry';
}
function buildWave(n){
  const s = waveSpec(n), q = [];
  const push = (kind) => {
    const k = KIND[kind];
    q.push({ kind,
      hp: Math.max(1, Math.round(s.hp * k.hp)), maxHp: Math.max(1, Math.round(s.hp * k.hp)),
      speed: s.speed * k.sp * (0.9 + Math.random()*0.2),
      reward: Math.max(1, Math.round(s.reward * k.rw)), r: k.r, leak: k.leak });
  };
  if(n === 50){
    push('boss'); push('mini'); push('mini');
    for(let i=0;i<s.count;i++) push(pickKind(n));
  } else if(n % 10 === 0){
    push('boss');
    for(let i=0;i<s.count;i++) push(pickKind(n));
  } else {
    if(n % 5 === 0) push('mini');
    for(let i=0;i<s.count;i++) push(pickKind(n));
  }
  return { queue: q, interval: s.interval };
}
function startWave(){
  if(state !== 'play' || waveActive || wave > 50) return;
  const b = buildWave(wave);
  queue = b.queue; spawnInterval = b.interval; spawnT = 0.3;
  waveActive = true; defSel = null; shopSel = null;
  sfx('start');
  if(wave === 50) addText(W/2, FIELD_Y+130, '⚠ THE FINAL ASSAULT ⚠', '#ff5d5d', 34);
  else if(wave % 10 === 0) addText(W/2, FIELD_Y+130, '⚠ LANDSHIP — WAVE ' + wave + ' ⚠', '#ff8a5d', 32);
  else if(wave % 5 === 0) addText(W/2, FIELD_Y+130, 'ARMORED CAR — WAVE ' + wave, '#ffd166', 28);
  else addText(W/2, FIELD_Y+130, 'WAVE ' + wave, '#e8ecf0', 30);
}
function spawnEnemy(q){
  enemies.push({ x: 26 + Math.random()*(W-52), y: FIELD_Y + 12 + Math.random()*22,
    hp: q.hp, maxHp: q.maxHp, speed: q.speed, reward: q.reward, r: q.r, leak: q.leak,
    kind: q.kind, phase: Math.random()*6.28, wob: Math.random()*6.28, smokeT: 0, dead: false });
}
function killEnemy(e){
  if(e.dead) return;
  e.dead = true;
  gold += e.reward; score += e.reward*10 + wave*5;
  addText(e.x, e.y - 14, '+$' + e.reward, '#ffe27a', (e.kind === 'boss' || e.kind === 'mini') ? 19 : 13);
  if(FOOT_KINDS[e.kind]){
    decals.push({ x: e.x, y: e.y, r: 4 + Math.random()*5, rot: Math.random()*3.14 });
    if(decals.length > 150) decals.shift();
    sfx('kill');
  } else {
    smoke.push(mkSmoke(e.x, e.y, 9 + Math.random()*6, 1.8));
    flashes.push({ x: e.x, y: e.y, r: e.r*1.1, ttl: 0.16, max: 0.16 });
    sfx('boom');
  }
}
function explode(x,y,dmg,splash,big){
  for(const e of enemies){
    if(e.dead) continue;
    const dx = e.x - x, dy = e.y - y, rr2 = splash + e.r*0.5;
    if(dx*dx + dy*dy <= rr2*rr2){ e.hp -= dmg; if(e.hp <= 0) killEnemy(e); }
  }
  flashes.push({ x, y, r: splash*0.72, ttl: 0.18, max: 0.18 });
  const n = big ? 9 : 6;
  for(let i=0;i<n;i++)
    smoke.push(mkSmoke(x + (Math.random()-0.5)*splash*0.7, y + (Math.random()-0.5)*splash*0.4,
                       8 + Math.random()*10, 2.2 + Math.random()*1.5));
  scorch.push({ x, y, r: splash*0.55 });
  if(scorch.length > 46) scorch.shift();
  if(big) shakeT = Math.max(shakeT, 0.35);
  sfx('boom');
}
function fireArtillery(x,y){
  if(artCD > 0 || state !== 'play') return;
  artCD = 25; artArmed = false;
  for(let i=0;i<3;i++)
    artShells.push({ x: x + (Math.random()-0.5)*84, y: y + (Math.random()-0.5)*84, t: -(0.5 + i*0.4) });
  sfx('whistle');
  addText(x, y - 30, 'ARTILLERY INBOUND', '#ff8a5d', 17);
}

// ================= ACTIONS =================
function tryPlace(x,y){
  const def = DEF_DEFS[shopSel];
  if(!def) return;
  if(y < PLACE_MIN_Y){ deny('Too close to the enemy trench'); return; }
  if(y > SHOP_Y - 8){ deny('Off the field'); return; }
  for(const d of defs){
    const dx = d.x - x, dy = d.y - y;
    if(dx*dx + dy*dy < 30*30){ deny('Too crowded'); return; }
  }
  if(gold < def.cost){ deny('Not enough gold'); return; }
  gold -= def.cost;
  defs.push(mkDef(shopSel, x, y));
  sfx('place');
  if(!waveActive) saveGame();
}
function tryUpgrade(){
  const d = defSel; if(!d) return;
  const def = DEF_DEFS[d.type];
  if(!def.lv || d.lvl >= 2) return;
  const cost = def.lv[d.lvl + 1].cost;
  if(gold < cost){ deny('Not enough gold'); return; }
  gold -= cost; d.invested += cost; d.lvl++;
  sfx('evolve');
  addText(d.x, d.y - 26, 'LEVEL ' + (d.lvl + 1), '#7CFC9A', 15);
  if(!waveActive) saveGame();
}
function trySell(){
  const d = defSel; if(!d) return;
  const val = Math.floor(d.invested * 0.7);
  gold += val;
  addText(d.x, d.y - 20, '+$' + val, '#ffe27a', 14);
  defs = defs.filter(x => x !== d);
  defSel = null;
  sfx('coin');
  if(!waveActive) saveGame();
}
function gameOver(){ state = 'defeat'; waveActive = false; clearSave(); sfx('leak'); }
function victory(){ state = 'victory'; waveActive = false; clearSave(); sfx('evolve'); }
function newGame(){
  wave = 1; gold = 250; lives = 20; score = 0;
  defs = []; enemies = []; queue = []; shells = []; artShells = [];
  tracers = []; muzzle = []; smoke = []; flashes = []; texts = []; decals = []; scorch = [];
  waveActive = false; speed = 1; paused = false; time = 0;
  shopSel = null; defSel = null; leakFlash = 0; shakeT = 0;
  artCD = 0; artArmed = false;
  clearSave(); state = 'play';
}

// ================= UPDATE =================
function update(dt){
  if(state !== 'play' || paused) return;
  const sdt = Math.min(dt, 0.05) * speed;
  time += sdt;
  if(artCD > 0) artCD -= sdt;
  if(leakFlash > 0) leakFlash -= sdt;
  if(shakeT > 0) shakeT -= sdt;
  if(denyT > 0) denyT -= sdt;

  // spawning
  if(waveActive && queue.length){
    spawnT -= sdt;
    while(spawnT <= 0 && queue.length){ spawnEnemy(queue.shift()); spawnT += spawnInterval; }
  }
  // artillery shells landing
  for(let i = artShells.length - 1; i >= 0; i--){
    const sh = artShells[i]; sh.t += sdt;
    if(sh.t >= 0){ artShells.splice(i, 1); explode(sh.x, sh.y, 150, 88, true); }
  }
  // mortar shells in flight
  for(let i = shells.length - 1; i >= 0; i--){
    const sh = shells[i]; sh.t += sdt / sh.dur;
    if(sh.t >= 1){ shells.splice(i, 1); explode(sh.tx, sh.ty, sh.dmg, sh.splash, false); }
  }
  // enemies advance
  for(const e of enemies){
    if(e.dead) continue;
    let sf = 1;
    for(const d of defs){
      if(d.type !== 'wire') continue;
      const dx = e.x - d.x, dy = e.y - d.y, wr = DEF_DEFS.wire.radius + e.r;
      if(dx*dx + dy*dy < wr*wr) sf = Math.min(sf, 1 - DEF_DEFS.wire.slow);
    }
    e.y += e.speed * sf * sdt;
    e.x += Math.sin(e.phase + time * 1.4) * 13 * sdt;
    if(e.x < 16) e.x = 16;
    if(e.x > W - 16) e.x = W - 16;
    e.wob += sdt * 7;
    if(e.kind === 'tank' || e.kind === 'boss' || e.kind === 'mini'){
      e.smokeT -= sdt;
      if(e.smokeT <= 0){ e.smokeT = 0.3; smoke.push(mkSmoke(e.x + (Math.random()-0.5)*10, e.y - e.r, 5 + Math.random()*5, 1.5)); }
    }
    if(e.y >= LEAK_Y){
      e.dead = true;
      lives -= e.leak;
      leakFlash = 0.4;
      addText(W - 90, SHOP_Y - 76, '-' + e.leak + ' ❤', '#ff5d5d', 22);
      sfx('leak');
      if(lives <= 0){ lives = 0; gameOver(); return; }
    }
  }
  // barbed wire wears out
  for(let i = defs.length - 1; i >= 0; i--){
    const d = defs[i];
    if(d.type !== 'wire') continue;
    const nowIn = new Set(), wr = DEF_DEFS.wire.radius;
    for(const e of enemies){
      if(e.dead) continue;
      const dx = e.x - d.x, dy = e.y - d.y;
      if(dx*dx + dy*dy < (wr + e.r) * (wr + e.r)) nowIn.add(e);
    }
    for(const e of d.inside){ if(!nowIn.has(e)) d.integrity--; }
    d.inside = nowIn;
    if(d.integrity <= 0){ defs.splice(i, 1); addText(d.x, d.y, 'WIRE WORN OUT', '#ffb0b0', 13); }
  }
  // mines trigger
  for(let i = defs.length - 1; i >= 0; i--){
    const d = defs[i];
    if(d.type !== 'mine') continue;
    let boom = false;
    for(const e of enemies){
      if(e.dead) continue;
      const dx = e.x - d.x, dy = e.y - d.y, tr = DEF_DEFS.mine.trigger + e.r * 0.5;
      if(dx*dx + dy*dy < tr * tr){ boom = true; break; }
    }
    if(boom){ defs.splice(i, 1); explode(d.x, d.y, DEF_DEFS.mine.dmg, DEF_DEFS.mine.splash, true); }
  }
  // defenses fire
  for(const d of defs){
    if(d.type === 'wire' || d.type === 'mine') continue;
    const st = defStats(d);
    d.cd -= sdt;
    let best = null, bd = -1;
    for(const e of enemies){
      if(e.dead) continue;
      const dx = e.x - d.x, dy = e.y - d.y, R = st.range + e.r * 0.4;
      if(dx*dx + dy*dy <= R * R && e.y > bd){ bd = e.y; best = e; }
    }
    d.target = best;
    if(best) d.angle = Math.atan2(best.y - d.y, best.x - d.x);
    if(!best || d.cd > 0) continue;
    d.cd = 1 / st.rate;
    if(d.type === 'mortar'){
      const dist = Math.hypot(best.x - d.x, best.y - d.y);
      shells.push({ sx: d.x, sy: d.y, tx: best.x, ty: best.y, t: 0,
                    dur: Math.min(1.3, Math.max(0.45, dist / 300)), dmg: st.dmg, splash: st.splash });
      sfx('mortar');
    } else {
      best.hp -= st.dmg;
      tracers.push({ x1: d.x, y1: d.y - 4, x2: best.x, y2: best.y, ttl: 0.09,
                     color: d.type === 'sniper' ? '#ffe9a8' : '#e8c97a', big: d.type === 'sniper' });
      muzzle.push({ x: d.x + Math.cos(d.angle) * 16, y: d.y + Math.sin(d.angle) * 16, ttl: 0.05 });
      sfx(d.type === 'sniper' ? 'sniper' : 'gun');
      if(best.hp <= 0) killEnemy(best);
    }
  }
  if(enemies.some(e => e.dead)) enemies = enemies.filter(e => !e.dead);

  // wave complete?
  if(waveActive && !queue.length && !enemies.length){
    waveActive = false;
    const bonus = 25 + wave * 3;
    gold += bonus; score += 100 + wave * 10;
    addText(W/2, FIELD_Y + 180, 'WAVE ' + wave + ' CLEAR  +$' + bonus, '#7CFC9A', 24);
    sfx('coin');
    wave++;
    if(wave > 50){ victory(); }
    else saveGame();
  }
}
// visual-only effects (run even when paused / in menu)
function updateFx(dt){
  for(const f of flakes){
    f.y += f.sp * dt;
    f.x += Math.sin(f.ph + time * 0.7 + f.y * 0.01) * 9 * dt;
    if(f.y > H + 3){ f.y = -3; f.x = Math.random() * W; }
    if(f.x < -3) f.x = W + 3; else if(f.x > W + 3) f.x = -3;
  }
  for(let i = smoke.length - 1; i >= 0; i--){
    const s = smoke[i];
    s.ttl -= dt; s.x += s.vx * dt; s.y += s.vy * dt; s.r += 5.5 * dt;
    if(s.ttl <= 0) smoke.splice(i, 1);
  }
  for(let i = flashes.length - 1; i >= 0; i--){ flashes[i].ttl -= dt; if(flashes[i].ttl <= 0) flashes.splice(i, 1); }
  for(let i = tracers.length - 1; i >= 0; i--){ tracers[i].ttl -= dt; if(tracers[i].ttl <= 0) tracers.splice(i, 1); }
  for(let i = muzzle.length - 1; i >= 0; i--){ muzzle[i].ttl -= dt; if(muzzle[i].ttl <= 0) muzzle.splice(i, 1); }
  for(let i = texts.length - 1; i >= 0; i--){
    const t = texts[i]; t.ttl -= dt; t.y -= 30 * dt;
    if(t.ttl <= 0) texts.splice(i, 1);
  }
}

// ================= LAYOUT (shared by draw + clicks) =================
const UI = {
  mute:   { x: W-96, y: 12, w: 40, h: 40 },
  restart:{ x: W-52, y: 12, w: 40, h: 40 },
  art:    { x: 622, y: 12, w: 138, h: 40 },
  cards:  SHOP_ORDER.map((t,i) => ({ x: 12 + i*160, y: SHOP_Y + 12, w: 150, h: 96, type: t })),
  start:  { x: 824, y: SHOP_Y + 8,  w: 124, h: 54 },
  speed:  { x: 824, y: SHOP_Y + 68, w: 60,  h: 44 },
  pause:  { x: 890, y: SHOP_Y + 68, w: 58,  h: 44 },
  upgrade:{ x: 520, y: SHOP_Y + 16, w: 190, h: 46 },
  sell:   { x: 720, y: SHOP_Y + 16, w: 110, h: 46 },
  pclose: { x: 850, y: SHOP_Y + 16, w: 46,  h: 46 },
  menuStart:   { x: W/2 - 150, y: 528, w: 300, h: 60 },
  menuContinue:{ x: W/2 - 150, y: 602, w: 300, h: 54 },
  again:  { x: W/2 - 150, y: 500, w: 300, h: 60 },
};
function inRect(x,y,r){ return x >= r.x && x <= r.x + r.w && y >= r.y && y <= r.y + r.h; }

// ================= RENDER =================
function render(){
  ctx.save();
  if(shakeT > 0) ctx.translate((Math.random()-0.5) * 14 * shakeT, (Math.random()-0.5) * 14 * shakeT);
  drawField();
  drawGhost();
  for(const d of defs) drawDef(d);
  drawShells();
  for(const e of enemies) drawEnemy(e);
  drawFx();
  drawTexts();
  drawHUD(); drawBottom();
  drawSnow();
  drawVignette();
  if(leakFlash > 0){ ctx.fillStyle = 'rgba(160,20,20,' + (leakFlash * 0.45) + ')'; ctx.fillRect(0, 0, W, H); }
  if(denyT > 0 && denyMsg){
    ctx.fillStyle = '#ff9a9a'; ctx.font = 'bold 18px sans-serif'; ctx.textAlign = 'center';
    ctx.fillText(denyMsg, W/2, FIELD_Y + 44); ctx.textAlign = 'left';
  }
  if(state === 'menu') drawMenu();
  if(state === 'victory') drawEnd(true);
  if(state === 'defeat') drawEnd(false);
  ctx.restore();
}
function drawField(){
  // snow base
  ctx.fillStyle = '#dfe3e6'; ctx.fillRect(0, FIELD_Y, W, FIELD_H);
  const g = ctx.createLinearGradient(0, FIELD_Y, 0, SHOP_Y);
  g.addColorStop(0, 'rgba(120,130,140,0.20)'); g.addColorStop(0.5, 'rgba(255,255,255,0)'); g.addColorStop(1, 'rgba(90,80,60,0.14)');
  ctx.fillStyle = g; ctx.fillRect(0, FIELD_Y, W, FIELD_H);
  // speckles
  for(const s of speckles){
    ctx.fillStyle = 'rgba(105,112,120,' + s.a + ')';
    ctx.beginPath(); ctx.arc(s.x, s.y, s.r, 0, 7); ctx.fill();
  }
  // explosion scorch marks
  for(const s of scorch){
    ctx.fillStyle = 'rgba(52,46,40,0.5)';
    ctx.beginPath(); ctx.ellipse(s.x, s.y, s.r, s.r * 0.72, 0, 0, 7); ctx.fill();
    ctx.fillStyle = 'rgba(30,26,22,0.5)';
    ctx.beginPath(); ctx.ellipse(s.x, s.y, s.r * 0.55, s.r * 0.4, 0, 0, 7); ctx.fill();
  }
  // static craters
  for(const c of craters){
    ctx.fillStyle = 'rgba(110,100,88,0.55)';
    ctx.beginPath(); ctx.ellipse(c.x, c.y, c.r, c.r * 0.7, 0, 0, 7); ctx.fill();
    ctx.fillStyle = 'rgba(88,78,64,0.6)';
    ctx.beginPath(); ctx.ellipse(c.x, c.y, c.r * 0.62, c.r * 0.42, 0, 0, 7); ctx.fill();
  }
  // blood decals where infantry fell
  for(const d of decals){
    ctx.save(); ctx.translate(d.x, d.y); ctx.rotate(d.rot);
    ctx.fillStyle = 'rgba(96,14,14,0.5)';
    ctx.beginPath(); ctx.ellipse(0, 0, d.r, d.r * 0.62, 0, 0, 7); ctx.fill();
    ctx.restore();
  }
  // dead trees
  for(const t of trees) drawTree(t);
  // wrecked tank husks
  for(const w of wrecks) drawWreck(w);
  // trenches
  drawTrench(ENEMY_TRENCH_Y, '#7a5f40');
  drawTrench(PLAYER_TRENCH_Y, '#7a5f40');
  // base line marker on player trench
  ctx.strokeStyle = 'rgba(150,30,30,0.5)'; ctx.lineWidth = 2; ctx.setLineDash([10, 8]);
  ctx.beginPath(); ctx.moveTo(0, LEAK_Y + 8); ctx.lineTo(W, LEAK_Y + 8); ctx.stroke(); ctx.setLineDash([]);
  // artillery target markers
  for(const sh of artShells){
    const p = 0.6 + 0.4 * Math.sin(time * 10);
    ctx.strokeStyle = 'rgba(200,40,30,' + p + ')'; ctx.lineWidth = 2;
    ctx.beginPath(); ctx.arc(sh.x, sh.y, 15 + 3 * Math.sin(time * 10), 0, 7); ctx.stroke();
    ctx.beginPath();
    ctx.moveTo(sh.x - 20, sh.y); ctx.lineTo(sh.x - 7, sh.y);
    ctx.moveTo(sh.x + 7, sh.y); ctx.lineTo(sh.x + 20, sh.y);
    ctx.moveTo(sh.x, sh.y - 20); ctx.lineTo(sh.x, sh.y - 7);
    ctx.moveTo(sh.x, sh.y + 7); ctx.lineTo(sh.x, sh.y + 20);
    ctx.stroke();
  }
  if(artArmed && state === 'play'){
    ctx.fillStyle = 'rgba(200,40,30,0.9)'; ctx.font = 'bold 16px sans-serif'; ctx.textAlign = 'center';
    ctx.fillText('ARTILLERY ARMED — tap the field to fire', W/2, FIELD_Y + 24);
    ctx.textAlign = 'left';
  }
}
function strokePts(pts){
  ctx.beginPath(); ctx.moveTo(pts[0].x, pts[0].y);
  for(let i = 1; i < pts.length; i++) ctx.lineTo(pts[i].x, pts[i].y);
  ctx.stroke();
}
function drawTrench(baseY){
  const pts = trenchPts(baseY);
  ctx.lineJoin = 'round'; ctx.lineCap = 'round';
  ctx.strokeStyle = '#77572f'; ctx.lineWidth = 47; strokePts(pts);           // muddy rim / sandbags base
  ctx.strokeStyle = '#6b543a'; ctx.lineWidth = 42; strokePts(pts);           // mud
  ctx.strokeStyle = '#43331f'; ctx.lineWidth = 27; strokePts(pts);           // trench interior
  ctx.strokeStyle = 'rgba(20,14,8,0.55)'; ctx.lineWidth = 13;
  ctx.beginPath(); ctx.moveTo(pts[0].x, pts[0].y + 3);
  for(let i = 1; i < pts.length; i++) ctx.lineTo(pts[i].x, pts[i].y + 3);
  ctx.stroke();
  // sandbags along both edges
  ctx.fillStyle = '#8a7350';
  for(let s = 0; s < pts.length - 1; s++){
    const a = pts[s], b = pts[s + 1];
    for(let k = 0; k <= 4; k++){
      const x = a.x + (b.x - a.x) * k / 4, y = a.y + (b.y - a.y) * k / 4;
      ctx.beginPath(); ctx.ellipse(x, y - 22, 7, 4.4, 0, 0, 7); ctx.fill();
      ctx.beginPath(); ctx.ellipse(x + 9, y + 22, 7, 4.4, 0, 0, 7); ctx.fill();
    }
  }
  // duckboards
  ctx.fillStyle = 'rgba(146,116,74,0.5)';
  for(let s = 0; s < pts.length - 1; s++){
    const a = pts[s], b = pts[s + 1];
    for(let k = 1; k <= 2; k++){
      const x = a.x + (b.x - a.x) * k / 3, y = a.y + (b.y - a.y) * k / 3;
      ctx.fillRect(x - 9, y - 2, 18, 4);
    }
  }
}
function drawTree(t){
  ctx.save(); ctx.translate(t.x, t.y); ctx.rotate(t.lean); ctx.scale(t.s, t.s);
  ctx.strokeStyle = '#3d3830'; ctx.lineWidth = 4;
  ctx.beginPath(); ctx.moveTo(0, 10); ctx.lineTo(0, -14); ctx.stroke();
  ctx.lineWidth = 2.4;
  ctx.beginPath(); ctx.moveTo(0, -6); ctx.lineTo(-11, -18); ctx.stroke();
  ctx.beginPath(); ctx.moveTo(0, -10); ctx.lineTo(10, -22); ctx.stroke();
  ctx.beginPath(); ctx.moveTo(0, -14); ctx.lineTo(-3, -26); ctx.stroke();
  ctx.restore();
}
function drawWreck(w){
  ctx.save(); ctx.translate(w.x, w.y); ctx.rotate(w.rot);
  ctx.fillStyle = 'rgba(0,0,0,0.18)';
  ctx.beginPath(); ctx.ellipse(2, 5, 30, 15, 0, 0, 7); ctx.fill();
  ctx.fillStyle = '#4a443c'; rr(-26, -13, 52, 26, 4); ctx.fill();
  ctx.fillStyle = '#38332c'; rr(-26, -16, 52, 6, 3); ctx.fill(); rr(-26, 10, 52, 6, 3); ctx.fill();
  ctx.fillStyle = '#554e42'; ctx.beginPath(); ctx.arc(-2, 0, 10, 0, 7); ctx.fill();
  ctx.strokeStyle = '#2e2a24'; ctx.lineWidth = 4;
  ctx.beginPath(); ctx.moveTo(-2, 0); ctx.lineTo(24, -7); ctx.stroke();
  ctx.restore();
}
function drawGhost(){
  if(!shopSel || !mouse.in || state !== 'play') return;
  if(mouse.y < FIELD_Y || mouse.y >= SHOP_Y) return;
  const def = DEF_DEFS[shopSel];
  const range = def.lv ? def.lv[0].range : (def.radius || def.splash || 60);
  const bad = mouse.y < PLACE_MIN_Y;
  ctx.globalAlpha = 0.30;
  ctx.fillStyle = bad ? '#c03a30' : def.color;
  ctx.beginPath(); ctx.arc(mouse.x, mouse.y, range, 0, 7); ctx.fill();
  ctx.globalAlpha = 0.85;
  ctx.beginPath(); ctx.arc(mouse.x, mouse.y, 13, 0, 7); ctx.fill();
  ctx.globalAlpha = 1;
}
function drawDef(d){
  const def = DEF_DEFS[d.type];
  if(defSel === d){
    const st = def.lv ? defStats(d) : null;
    const rad = st ? st.range : (def.radius || def.splash || 40);
    ctx.fillStyle = 'rgba(255,255,255,0.13)';
    ctx.beginPath(); ctx.arc(d.x, d.y, rad, 0, 7); ctx.fill();
    ctx.strokeStyle = 'rgba(60,60,60,0.6)'; ctx.lineWidth = 1.5; ctx.setLineDash([7, 6]);
    ctx.beginPath(); ctx.arc(d.x, d.y, rad, 0, 7); ctx.stroke(); ctx.setLineDash([]);
  }
  ctx.fillStyle = 'rgba(40,36,30,0.25)';
  ctx.beginPath(); ctx.ellipse(d.x, d.y + 8, 16, 6, 0, 0, 7); ctx.fill();
  const s = 1 + d.lvl * 0.13;
  if(d.type === 'wire'){
    ctx.strokeStyle = '#7d838a'; ctx.lineWidth = 2.2;
    for(const o of [[-11, 0], [0, -4], [11, 0], [-5, 5], [6, 5]]){
      ctx.beginPath(); ctx.arc(d.x + o[0], d.y + o[1], 8, 0, 7); ctx.stroke();
    }
    ctx.strokeStyle = '#5c5348'; ctx.lineWidth = 3;
    ctx.beginPath(); ctx.moveTo(d.x - 16, d.y - 10); ctx.lineTo(d.x - 16, d.y + 9); ctx.stroke();
    ctx.beginPath(); ctx.moveTo(d.x + 16, d.y - 10); ctx.lineTo(d.x + 16, d.y + 9); ctx.stroke();
    return;
  }
  if(d.type === 'mine'){
    ctx.fillStyle = '#37312a'; ctx.beginPath(); ctx.arc(d.x, d.y, 8, 0, 7); ctx.fill();
    ctx.strokeStyle = '#241f19'; ctx.lineWidth = 2; ctx.beginPath(); ctx.arc(d.x, d.y, 8, 0, 7); ctx.stroke();
    ctx.fillStyle = '#a33327'; ctx.beginPath(); ctx.arc(d.x, d.y, 2.6, 0, 7); ctx.fill();
    return;
  }
  ctx.save(); ctx.translate(d.x, d.y); ctx.scale(s, s);
  if(d.type === 'mg'){
    ctx.fillStyle = '#8a7350';
    for(const o of [[-14, 8], [-7, 11], [0, 12], [7, 11], [14, 8]])
      { ctx.beginPath(); ctx.arc(o[0], o[1], 5.4, 0, 7); ctx.fill(); }
    ctx.fillStyle = '#596052'; ctx.beginPath(); ctx.arc(0, 2, 7.5, 0, 7); ctx.fill();
    ctx.fillStyle = '#3a4030'; ctx.beginPath(); ctx.arc(0, 0, 5.4, 0, 7); ctx.fill();
    ctx.save(); ctx.rotate(d.angle);
    ctx.strokeStyle = '#22252a'; ctx.lineWidth = 4.4;
    ctx.beginPath(); ctx.moveTo(0, 0); ctx.lineTo(17, 0); ctx.stroke();
    ctx.strokeStyle = '#3c4046'; ctx.lineWidth = 2;
    ctx.beginPath(); ctx.moveTo(13, -3); ctx.lineTo(13, 3); ctx.stroke();
    ctx.restore();
  } else if(d.type === 'sniper'){
    ctx.fillStyle = '#6a6a58'; ctx.beginPath(); ctx.ellipse(0, 3, 11, 5.4, 0, 0, 7); ctx.fill();
    ctx.fillStyle = '#4c4c3e'; ctx.beginPath(); ctx.arc(-2, 0, 5, 0, 7); ctx.fill();
    ctx.save(); ctx.rotate(d.angle);
    ctx.strokeStyle = '#26221c'; ctx.lineWidth = 2.6;
    ctx.beginPath(); ctx.moveTo(0, 0); ctx.lineTo(27, 0); ctx.stroke();
    ctx.fillStyle = '#c8cdd2'; ctx.beginPath(); ctx.arc(9, -2.4, 1.5, 0, 7); ctx.fill();
    ctx.restore();
    ctx.fillStyle = 'rgba(90,96,74,0.8)';
    ctx.beginPath(); ctx.arc(-9, -6, 3.4, 0, 7); ctx.fill();
    ctx.beginPath(); ctx.arc(8, 7, 3, 0, 7); ctx.fill();
  } else if(d.type === 'mortar'){
    ctx.fillStyle = '#494540'; ctx.beginPath(); ctx.arc(0, 0, 13, 0, 7); ctx.fill();
    ctx.strokeStyle = '#2e2b27'; ctx.lineWidth = 2; ctx.beginPath(); ctx.arc(0, 0, 13, 0, 7); ctx.stroke();
    ctx.strokeStyle = '#22252a'; ctx.lineWidth = 6; ctx.lineCap = 'round';
    ctx.beginPath(); ctx.moveTo(2, 3); ctx.lineTo(-6, -13); ctx.stroke();
    ctx.fillStyle = '#5d6167';
    ctx.beginPath(); ctx.arc(8, 7, 3, 0, 7); ctx.fill();
    ctx.beginPath(); ctx.arc(12, 4, 3, 0, 7); ctx.fill();
  }
  ctx.restore();
  // level pips
  for(let i = 0; i < 3; i++){
    ctx.fillStyle = i <= d.lvl ? '#e8c97a' : 'rgba(70,70,70,0.35)';
    ctx.beginPath(); ctx.arc(d.x - 10 + i * 10, d.y + 20, 3.2, 0, 7); ctx.fill();
  }
}
function drawShells(){
  for(const sh of shells){
    const x = sh.sx + (sh.tx - sh.sx) * sh.t, y = sh.sy + (sh.ty - sh.sy) * sh.t;
    const h = Math.sin(Math.PI * Math.min(1, sh.t)) * 48;
    ctx.fillStyle = 'rgba(40,40,40,0.28)';
    ctx.beginPath(); ctx.ellipse(x, y, 6, 2.6, 0, 0, 7); ctx.fill();
    ctx.fillStyle = '#2c2e30';
    ctx.beginPath(); ctx.arc(x, y - h, 3.6, 0, 7); ctx.fill();
  }
}
function drawEnemy(e){
  const wob = Math.sin(e.wob) * 0.7;
  ctx.fillStyle = 'rgba(40,42,46,0.25)';
  ctx.beginPath(); ctx.ellipse(e.x, e.y + e.r * 0.75, e.r * 0.95, e.r * 0.4, 0, 0, 7); ctx.fill();
  if(e.kind === 'tank' || e.kind === 'boss' || e.kind === 'mini'){
    drawTank(e, wob);
  } else {
    const uni = e.kind === 'officer' ? '#4c5544' : (e.kind === 'mgteam' ? '#565d49' : (e.kind === 'runner' ? '#6b7055' : '#5f6650'));
    ctx.fillStyle = uni;
    ctx.beginPath(); ctx.arc(e.x, e.y, e.r, 0, 7); ctx.fill();
    ctx.fillStyle = '#3a4030';   // helmet
    ctx.beginPath(); ctx.arc(e.x, e.y - e.r * 0.22, e.r * 0.78, Math.PI, 0); ctx.fill();
    ctx.strokeStyle = '#2c2e26'; ctx.lineWidth = 2;   // rifle
    ctx.beginPath(); ctx.moveTo(e.x + e.r * 0.5, e.y - 2); ctx.lineTo(e.x + e.r * 0.9, e.y + e.r * 0.8); ctx.stroke();
    if(e.kind === 'officer'){
      ctx.fillStyle = '#a33327';
      ctx.fillRect(e.x - e.r * 0.8, e.y - e.r * 0.42, e.r * 1.6, 2.4);
    }
    if(e.kind === 'mgteam'){
      ctx.fillStyle = '#33363b'; ctx.fillRect(e.x - 7, e.y + 2, 14, 5);
      ctx.fillStyle = uni; ctx.beginPath(); ctx.arc(e.x - 8, e.y + 6, 4.4, 0, 7); ctx.fill();
    }
  }
  if(e.hp < e.maxHp){
    const w = Math.max(26, e.r * 2), p = Math.max(0, e.hp / e.maxHp);
    ctx.fillStyle = 'rgba(20,20,20,0.6)'; ctx.fillRect(e.x - w/2, e.y - e.r - 11, w, 5);
    ctx.fillStyle = p > 0.5 ? '#7fae4c' : (p > 0.25 ? '#d8a03c' : '#c03a30');
    ctx.fillRect(e.x - w/2, e.y - e.r - 11, w * p, 5);
  }
}
function drawTank(e, wob){
  const boss = e.kind === 'boss', mini = e.kind === 'mini';
  const bw = boss ? 62 : (mini ? 36 : 46), bh = boss ? 42 : (mini ? 24 : 31);
  ctx.save(); ctx.translate(e.x, e.y + wob * 0.3);
  // tracks
  ctx.fillStyle = '#2b2b2d';
  rr(-bw/2, -bh/2, 9, bh, 3); ctx.fill();
  rr(bw/2 - 9, -bh/2, 9, bh, 3); ctx.fill();
  ctx.fillStyle = '#45464a';
  for(let i = 0; i < 4; i++){
    ctx.beginPath(); ctx.arc(-bw/2 + 4.5, -bh/2 + 6 + i * (bh - 12) / 3, 2.4, 0, 7); ctx.fill();
    ctx.beginPath(); ctx.arc(bw/2 - 4.5, -bh/2 + 6 + i * (bh - 12) / 3, 2.4, 0, 7); ctx.fill();
  }
  if(mini){   // armored car wheels
    ctx.fillStyle = '#1f1f21';
    for(const o of [[-13, -11], [13, -11], [-13, 11], [13, 11]])
      { ctx.beginPath(); ctx.arc(o[0], o[1], 4.6, 0, 7); ctx.fill(); }
  }
  // hull
  ctx.fillStyle = boss ? '#4c5054' : '#5d6167';
  rr(-bw/2 + 7, -bh/2 + 2, bw - 14, bh - 4, 4); ctx.fill();
  ctx.strokeStyle = '#33363a'; ctx.lineWidth = 1.6; rr(-bw/2 + 7, -bh/2 + 2, bw - 14, bh - 4, 4); ctx.stroke();
  ctx.fillStyle = 'rgba(255,255,255,0.10)'; ctx.fillRect(-bw/2 + 10, -bh/2 + 4, bw - 20, 4);
  // turret + barrel (pointing down toward player)
  ctx.fillStyle = boss ? '#3f4347' : '#4c5054';
  ctx.beginPath(); ctx.arc(0, -2, boss ? 12 : 8.5, 0, 7); ctx.fill();
  ctx.strokeStyle = '#26282c'; ctx.lineWidth = boss ? 5 : 3.6;
  ctx.beginPath(); ctx.moveTo(0, 0); ctx.lineTo(0, bh/2 + (boss ? 15 : 11)); ctx.stroke();
  if(boss){
    ctx.beginPath(); ctx.arc(-14, 6, 6, 0, 7); ctx.fill();
    ctx.beginPath(); ctx.moveTo(-14, 6); ctx.lineTo(-14, bh/2 + 9); ctx.stroke();
  }
  ctx.restore();
}
function drawFx(){
  for(const t of tracers){
    ctx.globalAlpha = Math.max(0, t.ttl / 0.09);
    ctx.strokeStyle = t.color; ctx.lineWidth = t.big ? 2.6 : 1.6;
    ctx.beginPath(); ctx.moveTo(t.x1, t.y1); ctx.lineTo(t.x2, t.y2); ctx.stroke();
  }
  ctx.globalAlpha = 1;
  for(const m of muzzle){
    ctx.fillStyle = 'rgba(255,205,90,0.9)';
    ctx.beginPath(); ctx.arc(m.x, m.y, 4.4, 0, 7); ctx.fill();
  }
  for(const f of flashes){
    const k = Math.max(0, f.ttl / f.max);
    ctx.globalAlpha = k;
    const g = ctx.createRadialGradient(f.x, f.y, 1, f.x, f.y, f.r);
    g.addColorStop(0, 'rgba(255,230,170,0.95)'); g.addColorStop(0.35, 'rgba(240,130,40,0.8)'); g.addColorStop(1, 'rgba(120,60,30,0)');
    ctx.fillStyle = g;
    ctx.beginPath(); ctx.arc(f.x, f.y, f.r, 0, 7); ctx.fill();
  }
  ctx.globalAlpha = 1;
  for(const s of smoke){
    const a = Math.max(0, s.ttl / s.max) * 0.42;
    ctx.fillStyle = 'rgba(96,98,102,' + a + ')';
    ctx.beginPath(); ctx.arc(s.x, s.y, s.r, 0, 7); ctx.fill();
  }
}
function drawTexts(){
  ctx.textAlign = 'center';
  for(const t of texts){
    ctx.globalAlpha = Math.min(1, t.ttl * 2);
    ctx.font = 'bold ' + t.size + 'px sans-serif';
    ctx.strokeStyle = 'rgba(20,18,14,0.65)'; ctx.lineWidth = 3;
    ctx.strokeText(t.text, t.x, t.y);
    ctx.fillStyle = t.color; ctx.fillText(t.text, t.x, t.y);
  }
  ctx.globalAlpha = 1; ctx.textAlign = 'left';
}
function drawSnow(){
  ctx.fillStyle = 'rgba(255,255,255,0.85)';
  for(const f of flakes){ ctx.beginPath(); ctx.arc(f.x, f.y, f.r, 0, 7); ctx.fill(); }
}
function drawVignette(){
  const g = ctx.createRadialGradient(W/2, H/2, H * 0.36, W/2, H/2, H * 0.78);
  g.addColorStop(0, 'rgba(0,0,0,0)'); g.addColorStop(1, 'rgba(10,10,12,0.30)');
  ctx.fillStyle = g; ctx.fillRect(0, 0, W, H);
}

function drawHUD(){
  ctx.fillStyle = '#1b1e23'; ctx.fillRect(0, 0, W, HUD_H);
  ctx.strokeStyle = 'rgba(200,205,210,0.25)'; ctx.lineWidth = 1;
  ctx.beginPath(); ctx.moveTo(0, HUD_H); ctx.lineTo(W, HUD_H); ctx.stroke();
  ctx.textAlign = 'left'; ctx.fillStyle = '#e8ecf0'; ctx.font = 'bold 20px sans-serif';
  ctx.fillText('WAVE ' + Math.min(wave, 50) + '/50', 16, 30);
  ctx.font = 'bold 19px sans-serif'; ctx.fillStyle = '#e8c97a';
  ctx.fillText('💰 ' + fmt(gold), 16, 55);
  ctx.fillStyle = lives <= 5 ? '#ff5d5d' : '#e08a8a';
  ctx.fillText('❤ ' + lives, 150, 55);
  ctx.fillStyle = '#a8b0ba'; ctx.font = '16px sans-serif';
  ctx.fillText('SCORE ' + fmt(score), 235, 55);
  if(waveActive){
    ctx.fillStyle = '#ffd166'; ctx.font = 'bold 17px sans-serif'; ctx.textAlign = 'center';
    ctx.fillText('👾 ' + (queue.length + enemies.length) + ' left', 480, 40); ctx.textAlign = 'left';
  } else if(state === 'play' && wave <= 50){
    ctx.fillStyle = '#8fce6e'; ctx.font = 'bold 16px sans-serif'; ctx.textAlign = 'center';
    ctx.fillText('Ready — start the wave when you are', 470, 40); ctx.textAlign = 'left';
  }
  // artillery button
  const a = UI.art;
  const ready = artCD <= 0;
  ctx.fillStyle = artArmed ? 'rgba(190,50,35,0.45)' : (ready ? 'rgba(190,120,50,0.28)' : 'rgba(90,90,100,0.30)');
  rr(a.x, a.y, a.w, a.h, 8); ctx.fill();
  ctx.strokeStyle = artArmed ? '#e05a3a' : (ready ? '#d8923c' : '#5a5e64'); ctx.lineWidth = 1.6;
  rr(a.x, a.y, a.w, a.h, 8); ctx.stroke();
  ctx.fillStyle = artArmed ? '#ffd9c9' : (ready ? '#f0d9b8' : '#9aa0a6');
  ctx.font = 'bold 13px sans-serif'; ctx.textAlign = 'center';
  ctx.fillText(artArmed ? '🎯 TAP TARGET' : (ready ? '🎯 ARTILLERY' : '🎯 ' + Math.ceil(artCD) + 's'), a.x + a.w/2, a.y + 26);
  ctx.textAlign = 'left';
  if(logoReady){
    const lhh = 30, lww = lhh * logoImg.width / logoImg.height;
    ctx.drawImage(logoImg, W - 172 - lww, 17, lww, lhh);
  } else {
    ctx.fillStyle = 'rgba(180,188,198,0.5)'; ctx.font = '11px sans-serif'; ctx.textAlign = 'right';
    ctx.fillText('WIKIBUSINESS', W - 176, 56); ctx.textAlign = 'left';
  }
  hudBtn(UI.mute, muted ? '🔇' : '🔊');
  hudBtn(UI.restart, '⟳');
}
function hudBtn(r, icon){
  ctx.fillStyle = 'rgba(220,225,230,0.10)'; rr(r.x, r.y, r.w, r.h, 8); ctx.fill();
  ctx.strokeStyle = 'rgba(220,225,230,0.35)'; ctx.lineWidth = 1.5; rr(r.x, r.y, r.w, r.h, 8); ctx.stroke();
  ctx.fillStyle = '#dfe4ea'; ctx.font = '20px sans-serif'; ctx.textAlign = 'center';
  ctx.fillText(icon, r.x + r.w/2, r.y + 27); ctx.textAlign = 'left';
}
function drawBottom(){
  ctx.fillStyle = '#191c20'; ctx.fillRect(0, SHOP_Y, W, H - SHOP_Y);
  ctx.strokeStyle = 'rgba(200,205,210,0.22)';
  ctx.beginPath(); ctx.moveTo(0, SHOP_Y); ctx.lineTo(W, SHOP_Y); ctx.stroke();
  if(defSel) drawDefPanel(); else drawShop();
}
function drawShop(){
  ctx.fillStyle = '#a8b0ba'; ctx.font = 'bold 13px sans-serif'; ctx.textAlign = 'left';
  ctx.fillText('DEPLOY  (tap a defense, then tap the field)', 16, SHOP_Y + 10);
  for(let i = 0; i < UI.cards.length; i++){
    const c = UI.cards[i], def = DEF_DEFS[c.type];
    const sel = shopSel === c.type, afford = gold >= def.cost;
    ctx.fillStyle = sel ? 'rgba(200,170,90,0.20)' : 'rgba(38,42,48,0.95)';
    rr(c.x, c.y, c.w, c.h, 10); ctx.fill();
    ctx.strokeStyle = sel ? '#d8b25c' : (afford ? 'rgba(170,178,188,0.4)' : 'rgba(120,120,130,0.22)');
    ctx.lineWidth = sel ? 3 : 1.5; rr(c.x, c.y, c.w, c.h, 10); ctx.stroke();
    ctx.fillStyle = def.color; rr(c.x, c.y, c.w, 6, 3); ctx.fill();
    ctx.globalAlpha = afford ? 1 : 0.45;
    ctx.fillStyle = '#e8ecf0'; ctx.font = 'bold 15px sans-serif';
    ctx.fillText(def.name, c.x + 11, c.y + 30);
    ctx.fillStyle = '#e8c97a'; ctx.font = 'bold 15px sans-serif';
    ctx.fillText('$' + def.cost, c.x + 11, c.y + 52);
    ctx.fillStyle = '#9aa4ae'; ctx.font = '11.5px sans-serif';
    ctx.fillText(def.desc, c.x + 11, c.y + 72);
    ctx.fillStyle = 'rgba(200,208,216,0.55)'; ctx.font = 'bold 12px sans-serif';
    ctx.fillText('[' + (i + 1) + ']', c.x + c.w - 28, c.y + 30);
    ctx.globalAlpha = 1;
  }
  const s = UI.start;
  ctx.fillStyle = waveActive ? 'rgba(90,90,100,0.4)' : 'rgba(110,170,80,0.28)';
  rr(s.x, s.y, s.w, s.h, 10); ctx.fill();
  ctx.strokeStyle = waveActive ? '#666' : '#8fce6e'; ctx.lineWidth = 2; rr(s.x, s.y, s.w, s.h, 10); ctx.stroke();
  ctx.fillStyle = waveActive ? '#999' : '#dcf2cd'; ctx.font = 'bold 16px sans-serif'; ctx.textAlign = 'center';
  ctx.fillText(waveActive ? 'FIGHTING…' : '▶ START', s.x + s.w/2, s.y + 23);
  ctx.font = 'bold 13px sans-serif';
  ctx.fillText('wave ' + Math.min(wave, 50), s.x + s.w/2, s.y + 42);
  ctx.textAlign = 'left';
  bigBtn(UI.speed, speed + '×');
  bigBtn(UI.pause, paused ? '▶' : '⏸');
}
function bigBtn(r, label){
  ctx.fillStyle = 'rgba(220,225,230,0.10)'; rr(r.x, r.y, r.w, r.h, 10); ctx.fill();
  ctx.strokeStyle = 'rgba(220,225,230,0.35)'; ctx.lineWidth = 1.5; rr(r.x, r.y, r.w, r.h, 10); ctx.stroke();
  ctx.fillStyle = '#dfe4ea'; ctx.font = 'bold 18px sans-serif'; ctx.textAlign = 'center';
  ctx.fillText(label, r.x + r.w/2, r.y + 29); ctx.textAlign = 'left';
}
function statLine(type, st){
  if(type === 'mortar') return 'DMG ' + st.dmg + '   •   ' + st.rate + '/s   •   RANGE ' + st.range + '   •   SPLASH ' + st.splash;
  return 'DMG ' + st.dmg + '   •   ' + st.rate + '/s   •   RANGE ' + st.range;
}
function drawDefPanel(){
  const d = defSel, def = DEF_DEFS[d.type];
  ctx.fillStyle = 'rgba(30,34,40,0.97)'; rr(8, SHOP_Y + 6, W - 16, 108, 10); ctx.fill();
  ctx.strokeStyle = '#8a8f96'; ctx.lineWidth = 2; rr(8, SHOP_Y + 6, W - 16, 108, 10); ctx.stroke();
  ctx.fillStyle = '#e8ecf0'; ctx.font = 'bold 19px sans-serif';
  ctx.fillText(def.name + (def.lv ? '  —  Level ' + (d.lvl + 1) : ''), 28, SHOP_Y + 36);
  ctx.fillStyle = '#a8b0ba'; ctx.font = '14px sans-serif';
  if(def.lv){
    ctx.fillText(statLine(d.type, defStats(d)), 28, SHOP_Y + 60);
    ctx.fillStyle = 'rgba(200,208,216,0.6)'; ctx.font = '12px sans-serif';
    if(d.lvl < 2) ctx.fillText('Next: ' + statLine(d.type, def.lv[d.lvl + 1]), 28, SHOP_Y + 84);
    else ctx.fillText('MAX level reached.', 28, SHOP_Y + 84);
  } else if(d.type === 'wire'){
    ctx.fillText('SLOW 45%   •   RADIUS ' + def.radius + '   •   INTEGRITY ' + Math.max(0, d.integrity) + '/' + def.dur, 28, SHOP_Y + 60);
  } else {
    ctx.fillText('DMG ' + def.dmg + '   •   SPLASH ' + def.splash + '   •   ARMED — one shot', 28, SHOP_Y + 60);
  }
  // upgrade button (leveled defenses only)
  if(def.lv){
    const e = UI.upgrade, can = d.lvl < 2;
    const cost = can ? def.lv[d.lvl + 1].cost : 0, afford = gold >= cost;
    ctx.fillStyle = !can ? 'rgba(90,90,100,0.4)' : (afford ? 'rgba(110,170,80,0.28)' : 'rgba(150,70,60,0.25)');
    rr(e.x, e.y, e.w, e.h, 10); ctx.fill();
    ctx.strokeStyle = !can ? '#666' : (afford ? '#8fce6e' : '#a05050'); ctx.lineWidth = 2; rr(e.x, e.y, e.w, e.h, 10); ctx.stroke();
    ctx.fillStyle = !can ? '#999' : (afford ? '#dcf2cd' : '#ffb0b0');
    ctx.font = 'bold 15px sans-serif'; ctx.textAlign = 'center';
    ctx.fillText(can ? '⬆ UPGRADE $' + cost : 'MAX', e.x + e.w/2, e.y + 29);
  } else {
    ctx.fillStyle = 'rgba(200,208,216,0.55)'; ctx.font = '13px sans-serif'; ctx.textAlign = 'center';
    ctx.fillText('(no upgrades)', UI.upgrade.x + UI.upgrade.w/2, UI.upgrade.y + 29);
  }
  ctx.textAlign = 'center';
  const sl = UI.sell, val = Math.floor(d.invested * 0.7);
  ctx.fillStyle = 'rgba(216,178,92,0.18)'; rr(sl.x, sl.y, sl.w, sl.h, 10); ctx.fill();
  ctx.strokeStyle = '#d8b25c'; ctx.lineWidth = 2; rr(sl.x, sl.y, sl.w, sl.h, 10); ctx.stroke();
  ctx.fillStyle = '#f0dfae'; ctx.font = 'bold 15px sans-serif';
  ctx.fillText('SELL +$' + val, sl.x + sl.w/2, sl.y + 29);
  const c = UI.pclose;
  ctx.fillStyle = 'rgba(140,150,160,0.15)'; rr(c.x, c.y, c.w, c.h, 10); ctx.fill();
  ctx.strokeStyle = '#8fa0a8'; ctx.lineWidth = 2; rr(c.x, c.y, c.w, c.h, 10); ctx.stroke();
  ctx.fillStyle = '#dfe8ea'; ctx.fillText('✕', c.x + c.w/2, c.y + 29);
  ctx.textAlign = 'left';
}
function drawMenu(){
  ctx.fillStyle = 'rgba(16,18,22,0.80)'; ctx.fillRect(0, 0, W, H);
  ctx.textAlign = 'center';
  if(logoReady){
    const lw = 280, lh = lw * logoImg.height / logoImg.width;
    ctx.drawImage(logoImg, W/2 - lw/2, 46, lw, lh);
  }
  ctx.fillStyle = '#e8ecf0'; ctx.font = 'bold 52px sans-serif';
  ctx.fillText('TRENCH DEFENSE', W/2, 288);
  ctx.fillStyle = '#d8b25c'; ctx.font = 'bold 24px sans-serif';
  ctx.fillText('Hold the line — 50 waves', W/2, 326);
  ctx.fillStyle = '#c3cad2'; ctx.font = '16px sans-serif';
  const lines = [
    'The enemy pours out of the far trench and crosses the snow.',
    'Tap a defense below, then tap the field to deploy it.',
    'Tap a placed defense to upgrade it (3 levels) or sell it.',
    'Barbed wire slows them. Mines end arguments. 🎯 Artillery (A)',
    'clears a whole patch of no-man\'s land — 25s to reload.',
    'Mini-boss every 5 waves, a LANDSHIP every 10… and wave 50.',
    'Lives lost: infantry 1 • tank 3 • bosses up to 8. Hold the line!',
  ];
  lines.forEach((l, i) => ctx.fillText(l, W/2, 372 + i * 27));
  menuBtn(UI.menuStart, '▶  START NEW GAME', '#8fce6e');
  if(hasSave()) menuBtn(UI.menuContinue, '↻  CONTINUE — WAVE ' + JSON.parse(localStorage.getItem(SAVE_KEY)).wave, '#7ab5d9');
  ctx.textAlign = 'left';
}
function menuBtn(r, label, color){
  ctx.fillStyle = 'rgba(24,28,34,0.96)'; rr(r.x, r.y, r.w, r.h, 12); ctx.fill();
  ctx.strokeStyle = color; ctx.lineWidth = 3; rr(r.x, r.y, r.w, r.h, 12); ctx.stroke();
  ctx.fillStyle = color; ctx.font = 'bold 21px sans-serif'; ctx.textAlign = 'center';
  ctx.fillText(label, r.x + r.w/2, r.y + 37); ctx.textAlign = 'left';
}
function drawEnd(win){
  ctx.fillStyle = 'rgba(14,16,20,0.86)'; ctx.fillRect(0, 0, W, H);
  ctx.textAlign = 'center';
  if(logoReady){
    const lw = 200, lh = lw * logoImg.height / logoImg.width;
    ctx.drawImage(logoImg, W/2 - lw/2, 92, lw, lh);
  }
  ctx.fillStyle = win ? '#8fce6e' : '#e05a4a'; ctx.font = 'bold 54px sans-serif';
  ctx.fillText(win ? '🏆 THE LINE HELD!' : '💀 TRENCH OVERRUN', W/2, 330);
  ctx.fillStyle = '#c3cad2'; ctx.font = '20px sans-serif';
  ctx.fillText(win ? 'Fifty waves repelled. The snow is quiet again.'
                   : 'You fell on wave ' + Math.min(wave, 50) + '. The enemy takes the trench.', W/2, 386);
  ctx.fillStyle = '#e8c97a'; ctx.font = 'bold 22px sans-serif';
  ctx.fillText('SCORE ' + fmt(score) + '   •   DEFENSES ' + defs.length, W/2, 428);
  menuBtn(UI.again, win ? '↻  PLAY AGAIN' : '↻  TRY AGAIN', win ? '#8fce6e' : '#e08a7a');
  ctx.textAlign = 'left';
}

// ================= INPUT =================
function canvasPos(ev){
  const r = cv.getBoundingClientRect();
  return { x: (ev.clientX - r.left) * W / r.width, y: (ev.clientY - r.top) * H / r.height };
}
cv.addEventListener('pointerdown', ev => {
  ev.preventDefault();
  try{ AC = AC || new (window.AudioContext || window.webkitAudioContext)(); if(AC.state === 'suspended') AC.resume(); }catch(e){}
  const p = canvasPos(ev);
  handleTap(p.x, p.y);
});
cv.addEventListener('pointermove', ev => {
  const p = canvasPos(ev);
  mouse.x = p.x; mouse.y = p.y; mouse.in = true;
});
cv.addEventListener('pointerleave', () => { mouse.in = false; });
cv.addEventListener('contextmenu', ev => ev.preventDefault());
function defAt(x,y){
  let best = null, bd = 32 * 32;
  for(const d of defs){
    const dx = d.x - x, dy = d.y - y, dd = dx*dx + dy*dy;
    if(dd < bd){ bd = dd; best = d; }
  }
  return best;
}
function handleTap(x,y){
  if(state === 'menu'){
    if(inRect(x, y, UI.menuStart)){ newGame(); return; }
    if(hasSave() && inRect(x, y, UI.menuContinue)){ if(loadGame()){ state = 'play'; } return; }
    return;
  }
  if(state === 'victory' || state === 'defeat'){
    if(inRect(x, y, UI.again)){ state = 'menu'; }
    return;
  }
  // HUD
  if(y < HUD_H){
    if(inRect(x, y, UI.mute)){ muted = !muted; return; }
    if(inRect(x, y, UI.restart)){ saveGame(); state = 'menu'; return; }
    if(inRect(x, y, UI.art)){
      if(artCD <= 0){ artArmed = !artArmed; sfx('click'); }
      else deny('Artillery reloading');
      return;
    }
    return;
  }
  // bottom area
  if(y >= SHOP_Y){
    if(defSel){
      if(DEF_DEFS[defSel.type].lv && inRect(x, y, UI.upgrade)){ tryUpgrade(); return; }
      if(inRect(x, y, UI.sell)){ trySell(); return; }
      if(inRect(x, y, UI.pclose)){ defSel = null; return; }
      return;
    }
    for(const c of UI.cards){
      if(inRect(x, y, c)){ shopSel = (shopSel === c.type ? null : c.type); defSel = null; sfx('click'); return; }
    }
    if(inRect(x, y, UI.start)){ startWave(); return; }
    if(inRect(x, y, UI.speed)){ speed = speed >= 3 ? 1 : speed + 1; return; }
    if(inRect(x, y, UI.pause)){ paused = !paused; return; }
    return;
  }
  // field
  if(artArmed){ fireArtillery(x, y); return; }
  if(shopSel){ tryPlace(x, y); return; }
  const d = defAt(x, y);
  defSel = d || null;
  if(d) sfx('click');
}
window.addEventListener('keydown', ev => {
  if(state !== 'play') return;
  const k = ev.key.toLowerCase();
  const idx = ['1','2','3','4','5'].indexOf(k);
  if(idx >= 0){ shopSel = (shopSel === SHOP_ORDER[idx] ? null : SHOP_ORDER[idx]); defSel = null; sfx('click'); }
  else if(k === 'escape'){ shopSel = null; defSel = null; artArmed = false; }
  else if(k === ' '){ ev.preventDefault(); startWave(); }
  else if(k === 'a'){ if(artCD <= 0){ artArmed = !artArmed; sfx('click'); } else deny('Artillery reloading'); }
  else if(k === 'f'){ speed = speed >= 3 ? 1 : speed + 1; }
  else if(k === 'p'){ paused = !paused; }
  else if(k === 'm'){ muted = !muted; }
});
window.addEventListener('pagehide', saveGame);

// ================= MAIN LOOP =================
let lastT = performance.now();
function loop(now){
  const dt = (now - lastT) / 1000; lastT = now;
  updateFx(Math.min(dt, 0.05));
  update(dt);
  render();
  requestAnimationFrame(loop);
}
render();
requestAnimationFrame(loop);
})();