// ═══ defs.js ═══
// ============================================================
//  DEFINITIONS — elements, enemies, weapons, upgrades
// ============================================================

// ── ELEMENTS ─────────────────────────────────────────────────
const ELEMENTS = {
  fire:      { name: 'Fire',      color: '#ff6b35', glow: '#ff3300', icon: '🔥' },
  ice:       { name: 'Ice',       color: '#7ecfff', glow: '#00cfff', icon: '❄️' },
  lightning: { name: 'Lightning', color: '#ffe033', glow: '#ffcc00', icon: '⚡' },
  poison:    { name: 'Poison',    color: '#7fff4f', glow: '#44ff00', icon: '☠️' },
  void:      { name: 'Void',      color: '#c77dff', glow: '#9900ff', icon: '🌀' },
  arcane:    { name: 'Arcane',    color: '#ff77e9', glow: '#ff00cc', icon: '✨' },
  physical:  { name: 'Physical',  color: '#c8c8c8', glow: '#ffffff', icon: '💢' },
};

// ── ENEMY TYPES ───────────────────────────────────────────────
const ENEMY_DEFS = [
  {
    id: 'grunt',
    name: 'GRUNT',
    desc: 'Basic foot soldier. No special traits.',
    hp: 8, speed: 0.9, radius: 7, armor: 0,
    color: '#aaaaaa', glowColor: '#ffffff',
    cost: 20, reward: 30,
    resistances: {},
    weaknesses: { poison: 1.3 },
    element: null,
    count: 1,
  },
  {
    id: 'runner',
    name: 'RUNNER',
    desc: 'Very fast, low HP. Hard to track.',
    hp: 5, speed: 2.35, radius: 5, armor: 0,
    color: '#00ff88', glowColor: '#00ff88',
    cost: 30, reward: 44,
    resistances: {},
    weaknesses: { lightning: 1.5, poison: 1.3 },
    element: null,
    count: 1,
  },
  {
    id: 'brute',
    name: 'BRUTE',
    desc: 'High HP and armor. Slow mover.',
    hp: 35, speed: 0.52, radius: 13, armor: 3,
    color: '#ff7043', glowColor: '#ff3300',
    cost: 80, reward: 112,
    resistances: { physical: 0.5 },
    weaknesses: { void: 1.8, fire: 1.4, poison: 1.3 },
    element: null,
    count: 1,
  },
  {
    id: 'swarm',
    name: 'SWARM',
    desc: 'Spawns 6 tiny units at once.',
    hp: 3, speed: 1.85, radius: 4, armor: 0,
    color: '#ce93d8', glowColor: '#cc00ff',
    cost: 60, reward: 84,
    resistances: {},
    weaknesses: { fire: 1.4, lightning: 1.4 },
    element: null,
    count: 6,
  },
  {
    id: 'phantom',
    name: 'PHANTOM',
    desc: '40% dodge. Void-touched.',
    hp: 6, speed: 1.7, radius: 7, armor: 0,
    color: '#c77dff', glowColor: '#9900ff',
    cost: 100, reward: 138,
    evasion: 0.3,
    resistances: { void: 0.3, arcane: 0.5 },
    weaknesses: { fire: 1.5 },
    element: 'void',
    count: 1,
  },
  {
    id: 'iceling',
    name: 'ICELING',
    desc: 'Ice elemental. Slows bullets on contact.',
    hp: 12, speed: 0.88, radius: 9, armor: 1,
    color: '#7ecfff', glowColor: '#00cfff',
    cost: 90, reward: 125,
    resistances: { ice: 0.0 },
    weaknesses: { fire: 1.6, lightning: 1.3 },
    element: 'ice',
    count: 1,
  },
  {
    id: 'sparkling',
    name: 'SPARKLING',
    desc: 'Lightning elemental. Fast and electric.',
    hp: 7, speed: 2.1, radius: 6, armor: 0,
    color: '#ffe033', glowColor: '#ffcc00',
    cost: 110, reward: 148,
    resistances: { lightning: 0.0 },
    weaknesses: { ice: 1.5, void: 1.3 },
    element: 'lightning',
    count: 1,
  },
  {
    id: 'venom',
    name: 'VENOM',
    desc: 'Poison elemental. Immune to DoT.',
    hp: 14, speed: 0.96, radius: 10, armor: 0,
    color: '#7fff4f', glowColor: '#44ff00',
    cost: 120, reward: 160,
    resistances: { poison: 0.0, fire: 0.6 },
    weaknesses: { ice: 1.4, arcane: 1.6 },
    element: 'poison',
    count: 1,
  },
  {
    id: 'titan',
    name: 'TITAN',
    desc: 'Massive HP, heavy armor, very slow.',
    hp: 120, speed: 0.31, radius: 20, armor: 8,
    color: '#ff1744', glowColor: '#ff0000',
    cost: 350, reward: 465,
    resistances: { physical: 0.4, fire: 0.7 },
    weaknesses: { void: 2.0, arcane: 1.5 },
    element: null,
    count: 1,
  },
  {
    id: 'wraith',
    name: 'WRAITH',
    desc: 'Void entity. Ignores 80% of armor.',
    hp: 18, speed: 1.38, radius: 9, armor: 0,
    color: '#9900ff', glowColor: '#6600cc',
    cost: 200, reward: 265,
    armorPen: 0.8,
    resistances: { void: 0.2, poison: 0.5 },
    weaknesses: { arcane: 2.0 },
    element: 'void',
    count: 1,
  },
];

// ── WEAPON DEFINITIONS ────────────────────────────────────────
const WEAPON_DEFS = [
  {
    id: 'cannon',
    name: 'CANNON',
    desc: 'Standard projectile. Reliable, upgradeable.',
    icon: '💣',
    cost: 0, // starting weapon
    defaultElement: 'physical',
    targeting: 'nearest',
    fireRate: 72,      // frames between shots
    damage: 4,
    projectileSpeed: 4.2,
    projectileRadius: 4,
    range: 9999,
    color: '#c8c8c8',
    type: 'projectile',
  },
  {
    id: 'flamethrower',
    name: 'FLAMETHROWER',
    desc: 'Continuous cone of fire. Medium range, applies burn.',
    icon: '🔥',
    cost: 800,
    defaultElement: 'fire',
    targeting: 'nearest',
    fireRate: 8,
    damage: 1,
    range: 230,
    coneAngle: 0.35,
    color: '#ff6b35',
    type: 'cone',
  },
  {
    id: 'chainlightning',
    name: 'CHAIN LIGHTNING',
    desc: 'Arcs between up to 3 enemies.',
    icon: '⚡',
    cost: 1200,
    defaultElement: 'lightning',
    targeting: 'nearest',
    fireRate: 70,
    damage: 4,
    chains: 3,
    chainRange: 120,
    color: '#ffe033',
    type: 'chain',
  },
  {
    id: 'mortar',
    name: 'MORTAR',
    desc: 'Lobbed shell with AoE explosion. Slow reload.',
    icon: '💥',
    cost: 1500,
    defaultElement: 'physical',
    targeting: 'group',
    fireRate: 180,
    damage: 12,
    aoeRadius: 60,
    projectileSpeed: 2.8,
    color: '#ff7043',
    type: 'mortar',
  },
  {
    id: 'laser',
    name: 'LASER',
    desc: 'Continuous beam piercing all enemies in a line.',
    icon: '🔴',
    cost: 2000,
    defaultElement: 'arcane',
    targeting: 'furthest',
    fireRate: 10,
    damage: 1,
    range: 9999,
    color: '#ff77e9',
    type: 'beam',
  },
  {
    id: 'freezebomb',
    name: 'FREEZE BOMB',
    desc: 'AoE ice explosion. Freezes enemies solid briefly.',
    icon: '❄️',
    cost: 1800,
    defaultElement: 'ice',
    targeting: 'group',
    fireRate: 150,
    damage: 5,
    aoeRadius: 75,
    freezeDuration: 180,
    projectileSpeed: 2.4,
    color: '#7ecfff',
    type: 'mortar',
  },
  {
    id: 'voidcannon',
    name: 'VOID CANNON',
    desc: 'Massive slow projectile. Strips armor, bypasses resistance.',
    icon: '🌀',
    cost: 2000,
    defaultElement: 'void',
    targeting: 'strongest',
    fireRate: 240,
    damage: 20,
    armorShred: 5,
    projectileSpeed: 1.8,
    projectileRadius: 12,
    color: '#c77dff',
    type: 'projectile',
  },
  {
    id: 'missilepod',
    name: 'MISSILE POD',
    desc: 'Fires homing AoE missiles at 3 targets simultaneously.',
    icon: '🚀',
    cost: 2400,
    defaultElement: 'fire',
    targeting: 'group',
    fireRate: 120,
    damage: 8,
    targets: 3,
    aoeRadius: 36,
    projectileSpeed: 3.6,
    color: '#ff4500',
    type: 'multi',
  },
  {
    id: 'arcaneturret',
    name: 'ARCANE TURRET',
    desc: 'Rapid magic bolts. Applies Amplify debuff (+25% dmg taken).',
    icon: '✨',
    cost: 2200,
    defaultElement: 'arcane',
    targeting: 'nearest',
    fireRate: 20,
    damage: 2,
    amplify: 0.25,
    projectileSpeed: 5.8,
    color: '#ff77e9',
    type: 'projectile',
  },
  {
    id: 'poisoncloud',
    name: 'POISON CLOUD',
    desc: 'Launches a lingering poison gas cloud.',
    icon: '☠️',
    cost: 1600,
    defaultElement: 'poison',
    targeting: 'group',
    fireRate: 130,
    damage: 2,
    dotDamage: 1,
    dotInterval: 30,
    dotDuration: 180,
    aoeRadius: 55,
    projectileSpeed: 2.2,
    color: '#7fff4f',
    type: 'mortar',
  },
];

const MAX_WEAPONS_PER_TYPE = 8;

// ── UPGRADE TREES ─────────────────────────────────────────────
// Tower general upgrades
const TOWER_UPGRADE_TREE = [
  {
    id: 'hp1', label: 'Reinforced Hull I', desc: '+5 Max HP',
    cost: 100, requires: [], effect: { maxHp: 5 },
  },
  {
    id: 'hp2', label: 'Reinforced Hull II', desc: '+10 Max HP',
    cost: 250, requires: ['hp1'], effect: { maxHp: 10 },
  },
  {
    id: 'hp3', label: 'Reinforced Hull III', desc: '+20 Max HP',
    cost: 600, requires: ['hp2'], effect: { maxHp: 20 },
  },
  {
    id: 'hp4', label: 'Reinforced Hull IV', desc: '+35 Max HP',
    cost: 1400, requires: ['hp3'], effect: { maxHp: 35 },
  },
  {
    id: 'hp5', label: 'Reinforced Hull V', desc: '+60 Max HP',
    cost: 3000, requires: ['hp4'], effect: { maxHp: 60 },
  },
  {
    id: 'armor1', label: 'Plating I', desc: '+1 Armor',
    cost: 150, requires: [], effect: { armor: 1 },
  },
  {
    id: 'armor2', label: 'Plating II', desc: '+2 Armor',
    cost: 400, requires: ['armor1'], effect: { armor: 2 },
  },
  {
    id: 'armor3', label: 'Plating III', desc: '+3 Armor',
    cost: 900, requires: ['armor2'], effect: { armor: 3 },
  },
  {
    id: 'armor4', label: 'Plating IV', desc: '+4 Armor',
    cost: 2000, requires: ['armor3'], effect: { armor: 4 },
  },
  {
    id: 'armor5', label: 'Plating V', desc: '+6 Armor',
    cost: 4500, requires: ['armor4'], effect: { armor: 6 },
  },
  {
    id: 'aim1', label: 'Servo Motors I', desc: '+0.015 Aim Speed',
    cost: 100, requires: [], effect: { aimSpeed: 0.015 },
  },
  {
    id: 'aim2', label: 'Servo Motors II', desc: '+0.02 Aim Speed',
    cost: 200, requires: ['aim1'], effect: { aimSpeed: 0.02 },
  },
  {
    id: 'aim3', label: 'Servo Motors III', desc: '+0.025 Aim Speed',
    cost: 350, requires: ['aim2'], effect: { aimSpeed: 0.025 },
  },
  {
    id: 'aim4', label: 'Servo Motors IV', desc: '+0.035 Aim Speed',
    cost: 600, requires: ['aim3'], effect: { aimSpeed: 0.035 },
  },
  {
    id: 'aim5', label: 'Servo Motors V', desc: '+0.05 Aim Speed',
    cost: 1200, requires: ['aim4'], effect: { aimSpeed: 0.05 },
  },
  {
    id: 'aim6', label: 'Servo Motors VI', desc: '+0.07 Aim Speed — Near instant',
    cost: 2500, requires: ['aim5'], effect: { aimSpeed: 0.07 },
  },
  {
    id: 'repair1', label: 'Field Repair', desc: 'Restore 5 HP',
    cost: 80, requires: [], effect: { repair: 5 }, repeatable: true,
  },
  {
    id: 'slot2', label: 'Weapon Slot II', desc: 'Unlock 2nd weapon slot',
    cost: 500, requires: [], effect: { weaponSlot: 2 },
  },
  {
    id: 'slot3', label: 'Weapon Slot III', desc: 'Unlock 3rd weapon slot',
    cost: 1500, requires: ['slot2'], effect: { weaponSlot: 3 },
  },
  {
    id: 'slot4', label: 'Weapon Slot IV', desc: 'Unlock 4th weapon slot',
    cost: 3500, requires: ['slot3'], effect: { weaponSlot: 4 },
  },
  {
    id: 'slot5', label: 'Weapon Slot V', desc: 'Unlock 5th weapon slot',
    cost: 7000, requires: ['slot4'], effect: { weaponSlot: 5 },
  },
  {
    id: 'slot6', label: 'Weapon Slot VI', desc: 'Unlock 6th weapon slot',
    cost: 12000, requires: ['slot5'], effect: { weaponSlot: 6 },
  },
  {
    id: 'slot7', label: 'Weapon Slot VII', desc: 'Unlock 7th weapon slot',
    cost: 20000, requires: ['slot6'], effect: { weaponSlot: 7 },
  },
  {
    id: 'slot8', label: 'Weapon Slot VIII', desc: 'Unlock 8th weapon slot',
    cost: 30000, requires: ['slot7'], effect: { weaponSlot: 8 },
  },
  {
    id: 'range1', label: 'Scanner I',   desc: '+40 range',
    cost: 180, requires: [], effect: { range: 40 },
  },
  {
    id: 'range2', label: 'Scanner II',  desc: '+60 range',
    cost: 450, requires: ['range1'], effect: { range: 60 },
  },
  {
    id: 'range3', label: 'Scanner III', desc: '+80 range',
    cost: 1000, requires: ['range2'], effect: { range: 80 },
  },
  {
    id: 'range4', label: 'Scanner IV',  desc: '+100 range — max coverage',
    cost: 2400, requires: ['range3'], effect: { range: 100 },
  },
  {
    id: 'shield_dome', label: 'Dome Shield', desc: 'Buy dome shield system',
    cost: 800, requires: [], effect: { shield: 'dome' },
  },
  {
    id: 'shield_dir', label: 'Directional Shield', desc: 'Buy directional shield',
    cost: 600, requires: [], effect: { shield: 'directional' },
  },
];

// Per-weapon upgrade trees — each node has a `category` for grouped display
const WEAPON_UPGRADE_TREES = {
  cannon: [
    // Damage
    { id: 'dmg1', label: 'Damage I',    desc: '+2 damage', cost: 80,  requires: [],       effect: { damage: 2 }, category: 'Damage' },
    { id: 'dmg2', label: 'Damage II',   desc: '+3 damage', cost: 200, requires: ['dmg1'], effect: { damage: 3 }, category: 'Damage' },
    { id: 'dmg3', label: 'Damage III',  desc: '+5 damage', cost: 450, requires: ['dmg2'], effect: { damage: 5 }, category: 'Damage' },
    { id: 'dmg4', label: 'Damage IV',   desc: '+8 damage', cost: 900, requires: ['dmg3'], effect: { damage: 8 }, category: 'Damage' },
    // Fire Rate
    { id: 'rate1', label: 'Fire Rate I',  desc: '-15 frames', cost: 100, requires: [],        effect: { fireRate: -15 }, category: 'Fire Rate' },
    { id: 'rate2', label: 'Fire Rate II', desc: '-20 frames', cost: 250, requires: ['rate1'], effect: { fireRate: -20 }, category: 'Fire Rate' },
    { id: 'rate3', label: 'Fire Rate III',desc: '-25 frames', cost: 550, requires: ['rate2'], effect: { fireRate: -25 }, category: 'Fire Rate' },
    // Velocity
    { id: 'speed1', label: 'Velocity I',  desc: '+3 proj speed', cost: 90,  requires: [],         effect: { projectileSpeed: 3 }, category: 'Velocity' },
    { id: 'speed2', label: 'Velocity II', desc: '+4 proj speed', cost: 220, requires: ['speed1'], effect: { projectileSpeed: 4 }, category: 'Velocity' },
    { id: 'speed3', label: 'Velocity III',desc: '+5 proj speed', cost: 500, requires: ['speed2'], effect: { projectileSpeed: 5 }, category: 'Velocity' },
    // Special
    { id: 'pierce1', label: 'Piercing I',   desc: 'Pierce 1 extra',  cost: 200,  requires: ['dmg1'],    effect: { pierce: 1 }, category: 'Special' },
    { id: 'pierce2', label: 'Piercing II',  desc: 'Pierce 2 extra',  cost: 500,  requires: ['pierce1'], effect: { pierce: 1 }, category: 'Special' },
    { id: 'pierce3', label: 'Piercing III', desc: 'Pierce 3 extra',  cost: 1100, requires: ['pierce2'], effect: { pierce: 1 }, category: 'Special' },
    { id: 'pierce4', label: 'Piercing IV',  desc: 'Pierce 4 extra',  cost: 2400, requires: ['pierce3'], effect: { pierce: 1 }, category: 'Special' },
    { id: 'pierce5', label: 'Piercing V',   desc: 'Pierce 5 extra',  cost: 5000, requires: ['pierce4'], effect: { pierce: 1 }, category: 'Special' },
    { id: 'crit1',   label: 'Crit I',       desc: '+10% crit',       cost: 180,  requires: ['dmg1'],    effect: { critChance: 0.10 }, category: 'Special' },
    { id: 'crit2',   label: 'Crit II',      desc: '+15% crit',       cost: 400,  requires: ['crit1'],   effect: { critChance: 0.15 }, category: 'Special' },
    { id: 'crit3',   label: 'Crit III',     desc: '+20% crit',       cost: 900,  requires: ['crit2'],   effect: { critChance: 0.20 }, category: 'Special' },
    // Elements
    { id: 'el1', label: 'Infuse: Slot 1', desc: 'Unlock 1st element slot', cost: 300,  requires: [],     effect: { canInfuse: true },  category: 'Elements' },
    { id: 'el2', label: 'Infuse: Slot 2', desc: 'Unlock 2nd element slot', cost: 800,  requires: ['el1'], effect: { canInfuse2: true }, category: 'Elements' },
    { id: 'el3', label: 'Infuse: Slot 3', desc: 'Unlock 3rd element slot', cost: 2000, requires: ['el2'], effect: { canInfuse3: true }, category: 'Elements' },
  ],
  flamethrower: [
    { id: 'dmg1', label: 'Heat I',   desc: '+1 dmg/tick', cost: 120, requires: [],       effect: { damage: 1 }, category: 'Damage' },
    { id: 'dmg2', label: 'Heat II',  desc: '+2 dmg/tick', cost: 300, requires: ['dmg1'], effect: { damage: 2 }, category: 'Damage' },
    { id: 'dmg3', label: 'Heat III', desc: '+3 dmg/tick', cost: 700, requires: ['dmg2'], effect: { damage: 3 }, category: 'Damage' },
    { id: 'range1', label: 'Range I',  desc: '+40 range', cost: 150, requires: [],         effect: { range: 40 }, category: 'Range' },
    { id: 'range2', label: 'Range II', desc: '+60 range', cost: 350, requires: ['range1'], effect: { range: 60 }, category: 'Range' },
    { id: 'range3', label: 'Range III',desc: '+80 range', cost: 800, requires: ['range2'], effect: { range: 80 }, category: 'Range' },
    { id: 'cone1', label: 'Wide Cone I',  desc: '+15° angle', cost: 200, requires: [],        effect: { coneAngle: 0.07 }, category: 'Cone' },
    { id: 'cone2', label: 'Wide Cone II', desc: '+20° angle', cost: 500, requires: ['cone1'], effect: { coneAngle: 0.10 }, category: 'Cone' },
    { id: 'burn1', label: 'Burn I',  desc: '+60 burn frames', cost: 180, requires: ['dmg1'], effect: { dotDuration: 60 },  category: 'Special' },
    { id: 'burn2', label: 'Burn II', desc: '+90 burn frames', cost: 400, requires: ['burn1'], effect: { dotDuration: 90 }, category: 'Special' },
    { id: 'el1', label: 'Infuse: Slot 1', desc: 'Unlock 1st element slot', cost: 300,  requires: [],      effect: { canInfuse: true },  category: 'Elements' },
    { id: 'el2', label: 'Infuse: Slot 2', desc: 'Unlock 2nd element slot', cost: 800,  requires: ['el1'], effect: { canInfuse2: true }, category: 'Elements' },
  ],
  chainlightning: [
    { id: 'dmg1', label: 'Voltage I',  desc: '+2 damage', cost: 150, requires: [],       effect: { damage: 2 }, category: 'Damage' },
    { id: 'dmg2', label: 'Voltage II', desc: '+4 damage', cost: 380, requires: ['dmg1'], effect: { damage: 4 }, category: 'Damage' },
    { id: 'dmg3', label: 'Voltage III',desc: '+6 damage', cost: 900, requires: ['dmg2'], effect: { damage: 6 }, category: 'Damage' },
    { id: 'chains1', label: 'Chain +1', desc: '+1 arc target', cost: 300, requires: [],           effect: { chains: 1 }, category: 'Chains' },
    { id: 'chains2', label: 'Chain +2', desc: '+2 arc targets', cost: 700, requires: ['chains1'], effect: { chains: 2 }, category: 'Chains' },
    { id: 'chains3', label: 'Chain +3', desc: '+3 arc targets', cost: 1600, requires: ['chains2'],effect: { chains: 3 }, category: 'Chains' },
    { id: 'range1', label: 'Arc Range I',  desc: '+50 chain range', cost: 200, requires: [],         effect: { chainRange: 50 }, category: 'Range' },
    { id: 'range2', label: 'Arc Range II', desc: '+80 chain range', cost: 500, requires: ['range1'], effect: { chainRange: 80 }, category: 'Range' },
    { id: 'rate1', label: 'Frequency I',  desc: '-15 frames', cost: 150, requires: [],        effect: { fireRate: -15 }, category: 'Fire Rate' },
    { id: 'rate2', label: 'Frequency II', desc: '-20 frames', cost: 400, requires: ['rate1'], effect: { fireRate: -20 }, category: 'Fire Rate' },
    { id: 'el1', label: 'Infuse: Slot 1', desc: 'Unlock 1st element slot', cost: 300,  requires: [],      effect: { canInfuse: true },  category: 'Elements' },
    { id: 'el2', label: 'Infuse: Slot 2', desc: 'Unlock 2nd element slot', cost: 800,  requires: ['el1'], effect: { canInfuse2: true }, category: 'Elements' },
  ],
  mortar: [
    { id: 'dmg1', label: 'Payload I',  desc: '+5 damage', cost: 200, requires: [],       effect: { damage: 5 }, category: 'Damage' },
    { id: 'dmg2', label: 'Payload II', desc: '+8 damage', cost: 500, requires: ['dmg1'], effect: { damage: 8 }, category: 'Damage' },
    { id: 'dmg3', label: 'Payload III',desc: '+12 damage',cost: 1100, requires: ['dmg2'],effect: { damage: 12}, category: 'Damage' },
    { id: 'aoe1', label: 'Blast Radius I',  desc: '+20 AoE', cost: 180, requires: [],       effect: { aoeRadius: 20 }, category: 'Blast' },
    { id: 'aoe2', label: 'Blast Radius II', desc: '+30 AoE', cost: 450, requires: ['aoe1'], effect: { aoeRadius: 30 }, category: 'Blast' },
    { id: 'aoe3', label: 'Blast Radius III',desc: '+40 AoE', cost: 950, requires: ['aoe2'], effect: { aoeRadius: 40 }, category: 'Blast' },
    { id: 'rate1', label: 'Reload I',  desc: '-40 frames', cost: 250, requires: [],        effect: { fireRate: -40 }, category: 'Fire Rate' },
    { id: 'rate2', label: 'Reload II', desc: '-50 frames', cost: 600, requires: ['rate1'], effect: { fireRate: -50 }, category: 'Fire Rate' },
    { id: 'speed1', label: 'Velocity I', desc: '+1.5 proj spd', cost: 200, requires: [], effect: { projectileSpeed: 1.5 }, category: 'Velocity' },
    { id: 'el1', label: 'Infuse: Slot 1', desc: 'Unlock 1st element slot', cost: 300,  requires: [],      effect: { canInfuse: true },  category: 'Elements' },
    { id: 'el2', label: 'Infuse: Slot 2', desc: 'Unlock 2nd element slot', cost: 800,  requires: ['el1'], effect: { canInfuse2: true }, category: 'Elements' },
    { id: 'el3', label: 'Infuse: Slot 3', desc: 'Unlock 3rd element slot', cost: 2000, requires: ['el2'], effect: { canInfuse3: true }, category: 'Elements' },
  ],
  laser: [
    { id: 'dmg1', label: 'Focus I',  desc: '+1 dmg/tick', cost: 180, requires: [],       effect: { damage: 1 }, category: 'Damage' },
    { id: 'dmg2', label: 'Focus II', desc: '+2 dmg/tick', cost: 450, requires: ['dmg1'], effect: { damage: 2 }, category: 'Damage' },
    { id: 'dmg3', label: 'Focus III',desc: '+3 dmg/tick', cost: 1000, requires: ['dmg2'],effect: { damage: 3 }, category: 'Damage' },
    { id: 'rate1', label: 'Frequency I',  desc: '-2 tick frames', cost: 200, requires: [],        effect: { fireRate: -2 }, category: 'Fire Rate' },
    { id: 'rate2', label: 'Frequency II', desc: '-2 tick frames', cost: 500, requires: ['rate1'], effect: { fireRate: -2 }, category: 'Fire Rate' },
    { id: 'rate3', label: 'Frequency III',desc: '-2 tick frames', cost: 1200, requires: ['rate2'],effect: { fireRate: -2 }, category: 'Fire Rate' },
    { id: 'width1', label: 'Wide Beam I',  desc: '+6 hit radius', cost: 300, requires: [],         effect: { projectileRadius: 6 }, category: 'Width' },
    { id: 'width2', label: 'Wide Beam II', desc: '+8 hit radius', cost: 700, requires: ['width1'], effect: { projectileRadius: 8 }, category: 'Width' },
    { id: 'el1', label: 'Infuse: Slot 1', desc: 'Unlock 1st element slot', cost: 300,  requires: [],      effect: { canInfuse: true },  category: 'Elements' },
    { id: 'el2', label: 'Infuse: Slot 2', desc: 'Unlock 2nd element slot', cost: 800,  requires: ['el1'], effect: { canInfuse2: true }, category: 'Elements' },
  ],
  freezebomb: [
    { id: 'dmg1', label: 'Cold I',  desc: '+3 damage', cost: 200, requires: [],       effect: { damage: 3 }, category: 'Damage' },
    { id: 'dmg2', label: 'Cold II', desc: '+5 damage', cost: 500, requires: ['dmg1'], effect: { damage: 5 }, category: 'Damage' },
    { id: 'aoe1', label: 'Blast I',  desc: '+25 AoE', cost: 220, requires: [],       effect: { aoeRadius: 25 }, category: 'Blast' },
    { id: 'aoe2', label: 'Blast II', desc: '+35 AoE', cost: 550, requires: ['aoe1'], effect: { aoeRadius: 35 }, category: 'Blast' },
    { id: 'freeze1', label: 'Deep Freeze I',  desc: '+60 freeze frames',  cost: 280, requires: [],           effect: { freezeDuration: 60 }, category: 'Freeze' },
    { id: 'freeze2', label: 'Deep Freeze II', desc: '+90 freeze frames',  cost: 600, requires: ['freeze1'],  effect: { freezeDuration: 90 }, category: 'Freeze' },
    { id: 'freeze3', label: 'Deep Freeze III',desc: '+120 freeze frames', cost: 1300, requires: ['freeze2'], effect: { freezeDuration: 120}, category: 'Freeze' },
    { id: 'rate1', label: 'Reload I', desc: '-40 frames', cost: 300, requires: [], effect: { fireRate: -40 }, category: 'Fire Rate' },
    { id: 'el1', label: 'Infuse: Slot 1', desc: 'Unlock 1st element slot', cost: 300,  requires: [],      effect: { canInfuse: true },  category: 'Elements' },
    { id: 'el2', label: 'Infuse: Slot 2', desc: 'Unlock 2nd element slot', cost: 800,  requires: ['el1'], effect: { canInfuse2: true }, category: 'Elements' },
  ],
  voidcannon: [
    { id: 'dmg1', label: 'Singularity I',  desc: '+8 damage',  cost: 300, requires: [],       effect: { damage: 8 },  category: 'Damage' },
    { id: 'dmg2', label: 'Singularity II', desc: '+15 damage', cost: 750, requires: ['dmg1'], effect: { damage: 15 }, category: 'Damage' },
    { id: 'dmg3', label: 'Singularity III',desc: '+25 damage', cost: 1600, requires: ['dmg2'],effect: { damage: 25 }, category: 'Damage' },
    { id: 'shred1', label: 'Armor Shred I',  desc: '+3 armor shred', cost: 400, requires: [],         effect: { armorShred: 3 }, category: 'Special' },
    { id: 'shred2', label: 'Armor Shred II', desc: '+5 armor shred', cost: 900, requires: ['shred1'], effect: { armorShred: 5 }, category: 'Special' },
    { id: 'speed1', label: 'Velocity I',  desc: '+1.5 proj spd', cost: 350, requires: [],         effect: { projectileSpeed: 1.5 }, category: 'Velocity' },
    { id: 'speed2', label: 'Velocity II', desc: '+2 proj spd',   cost: 800, requires: ['speed1'], effect: { projectileSpeed: 2 },   category: 'Velocity' },
    { id: 'size1',  label: 'Projectile Size I', desc: '+4 proj radius', cost: 400, requires: [], effect: { projectileRadius: 4 }, category: 'Size' },
    { id: 'rate1', label: 'Reload I', desc: '-50 frames', cost: 500, requires: [], effect: { fireRate: -50 }, category: 'Fire Rate' },
    { id: 'el1', label: 'Infuse: Slot 1', desc: 'Unlock 1st element slot', cost: 300,  requires: [],      effect: { canInfuse: true },  category: 'Elements' },
    { id: 'el2', label: 'Infuse: Slot 2', desc: 'Unlock 2nd element slot', cost: 800,  requires: ['el1'], effect: { canInfuse2: true }, category: 'Elements' },
    { id: 'el3', label: 'Infuse: Slot 3', desc: 'Unlock 3rd element slot', cost: 2000, requires: ['el2'], effect: { canInfuse3: true }, category: 'Elements' },
  ],
  missilepod: [
    { id: 'dmg1', label: 'Warhead I',  desc: '+4 damage', cost: 250, requires: [],       effect: { damage: 4 }, category: 'Damage' },
    { id: 'dmg2', label: 'Warhead II', desc: '+6 damage', cost: 600, requires: ['dmg1'], effect: { damage: 6 }, category: 'Damage' },
    { id: 'dmg3', label: 'Warhead III',desc: '+10 damage',cost: 1400, requires: ['dmg2'],effect: { damage: 10}, category: 'Damage' },
    { id: 'targets1', label: '+1 Target', desc: 'Fire at 1 more', cost: 500,  requires: [],           effect: { targets: 1 }, category: 'Targets' },
    { id: 'targets2', label: '+2 Targets',desc: 'Fire at 2 more', cost: 1200, requires: ['targets1'], effect: { targets: 2 }, category: 'Targets' },
    { id: 'targets3', label: '+3 Targets',desc: 'Fire at 3 more', cost: 2800, requires: ['targets2'], effect: { targets: 3 }, category: 'Targets' },
    { id: 'rate1', label: 'Reload I',  desc: '-30 frames', cost: 300, requires: [],        effect: { fireRate: -30 }, category: 'Fire Rate' },
    { id: 'rate2', label: 'Reload II', desc: '-40 frames', cost: 700, requires: ['rate1'], effect: { fireRate: -40 }, category: 'Fire Rate' },
    { id: 'speed1', label: 'Velocity I', desc: '+2 proj spd', cost: 300, requires: [], effect: { projectileSpeed: 2 }, category: 'Velocity' },
    { id: 'el1', label: 'Infuse: Slot 1', desc: 'Unlock 1st element slot', cost: 300,  requires: [],      effect: { canInfuse: true },  category: 'Elements' },
    { id: 'el2', label: 'Infuse: Slot 2', desc: 'Unlock 2nd element slot', cost: 800,  requires: ['el1'], effect: { canInfuse2: true }, category: 'Elements' },
  ],
  arcaneturret: [
    { id: 'dmg1', label: 'Potency I',  desc: '+1 damage', cost: 120, requires: [],       effect: { damage: 1 }, category: 'Damage' },
    { id: 'dmg2', label: 'Potency II', desc: '+2 damage', cost: 300, requires: ['dmg1'], effect: { damage: 2 }, category: 'Damage' },
    { id: 'dmg3', label: 'Potency III',desc: '+3 damage', cost: 700, requires: ['dmg2'], effect: { damage: 3 }, category: 'Damage' },
    { id: 'rate1', label: 'Frequency I',  desc: '-5 frames',  cost: 150, requires: [],        effect: { fireRate: -5 }, category: 'Fire Rate' },
    { id: 'rate2', label: 'Frequency II', desc: '-5 frames',  cost: 380, requires: ['rate1'], effect: { fireRate: -5 }, category: 'Fire Rate' },
    { id: 'rate3', label: 'Frequency III',desc: '-4 frames',  cost: 850, requires: ['rate2'], effect: { fireRate: -4 }, category: 'Fire Rate' },
    { id: 'amp1',  label: 'Amplify I',    desc: '+10% amp',   cost: 300, requires: ['dmg1'],  effect: { amplify: 0.10 }, category: 'Special' },
    { id: 'amp2',  label: 'Amplify II',   desc: '+15% amp',   cost: 700, requires: ['amp1'],  effect: { amplify: 0.15 }, category: 'Special' },
    { id: 'speed1',label: 'Velocity I',   desc: '+3 proj spd',cost: 200, requires: [],        effect: { projectileSpeed: 3 }, category: 'Velocity' },
    { id: 'el1', label: 'Infuse: Slot 1', desc: 'Unlock 1st element slot', cost: 300,  requires: [],      effect: { canInfuse: true },  category: 'Elements' },
    { id: 'el2', label: 'Infuse: Slot 2', desc: 'Unlock 2nd element slot', cost: 800,  requires: ['el1'], effect: { canInfuse2: true }, category: 'Elements' },
  ],
  poisoncloud: [
    { id: 'dmg1', label: 'Toxin I',  desc: '+1 dot dmg', cost: 150, requires: [],       effect: { dotDamage: 1 }, category: 'Damage' },
    { id: 'dmg2', label: 'Toxin II', desc: '+2 dot dmg', cost: 380, requires: ['dmg1'], effect: { dotDamage: 2 }, category: 'Damage' },
    { id: 'dmg3', label: 'Toxin III',desc: '+3 dot dmg', cost: 850, requires: ['dmg2'], effect: { dotDamage: 3 }, category: 'Damage' },
    { id: 'dur1', label: 'Duration I',  desc: '+60 cloud frames',  cost: 180, requires: [],        effect: { dotDuration: 60 }, category: 'Duration' },
    { id: 'dur2', label: 'Duration II', desc: '+90 cloud frames',  cost: 450, requires: ['dur1'],  effect: { dotDuration: 90 }, category: 'Duration' },
    { id: 'dur3', label: 'Duration III',desc: '+120 cloud frames', cost: 1000, requires: ['dur2'], effect: { dotDuration: 120}, category: 'Duration' },
    { id: 'aoe1', label: 'Cloud I',  desc: '+20 AoE', cost: 200, requires: [],       effect: { aoeRadius: 20 }, category: 'Blast' },
    { id: 'aoe2', label: 'Cloud II', desc: '+30 AoE', cost: 500, requires: ['aoe1'], effect: { aoeRadius: 30 }, category: 'Blast' },
    { id: 'rate1', label: 'Reload I', desc: '-30 frames', cost: 250, requires: [], effect: { fireRate: -30 }, category: 'Fire Rate' },
    { id: 'el1', label: 'Infuse: Slot 1', desc: 'Unlock 1st element slot', cost: 300,  requires: [],      effect: { canInfuse: true },  category: 'Elements' },
    { id: 'el2', label: 'Infuse: Slot 2', desc: 'Unlock 2nd element slot', cost: 800,  requires: ['el1'], effect: { canInfuse2: true }, category: 'Elements' },
  ],
};

// Shield upgrade trees
const SHIELD_UPGRADE_TREES = {
  dome: [
    { id: 'cap1', label: 'Capacity I', desc: '+5 shield HP', cost: 200, requires: [], effect: { capacity: 5 } },
    { id: 'cap2', label: 'Capacity II', desc: '+10 shield HP', cost: 500, requires: ['cap1'], effect: { capacity: 10 } },
    { id: 'cap3', label: 'Capacity III', desc: '+20 shield HP', cost: 1100, requires: ['cap2'], effect: { capacity: 20 } },
    { id: 'regen1', label: 'Recharge I', desc: '-30 frames recharge', cost: 300, requires: [], effect: { rechargeDelay: -30 } },
    { id: 'regen2', label: 'Recharge II', desc: '-60 frames recharge', cost: 700, requires: ['regen1'], effect: { rechargeDelay: -60 } },
    { id: 'reflect1', label: 'Reflect', desc: 'Reflect 20% dmg back', cost: 1500, requires: ['cap2'], effect: { reflect: 0.2 } },
  ],
  directional: [
    { id: 'arc1', label: 'Wide Arc I', desc: '+20° arc width', cost: 200, requires: [], effect: { arcWidth: 0.35 } },
    { id: 'arc2', label: 'Wide Arc II', desc: '+30° arc width', cost: 500, requires: ['arc1'], effect: { arcWidth: 0.52 } },
    { id: 'cap1', label: 'Capacity I', desc: '+8 shield HP', cost: 250, requires: [], effect: { capacity: 8 } },
    { id: 'cap2', label: 'Capacity II', desc: '+15 shield HP', cost: 600, requires: ['cap1'], effect: { capacity: 15 } },
    { id: 'speed1', label: 'Track Speed I', desc: '+50% shield rotation', cost: 300, requires: [], effect: { trackSpeed: 0.03 } },
    { id: 'speed2', label: 'Track Speed II', desc: '+100% shield rotation', cost: 700, requires: ['speed1'], effect: { trackSpeed: 0.06 } },
    { id: 'absorb1', label: 'Absorption I', desc: 'Block 25% more damage', cost: 400, requires: ['cap1'], effect: { absorption: 0.25 } },
  ],
};