/* Tower Defense — multiple themes */
:root,
[data-theme="default"] {
  --bg: #1a1d29;
  --bg-mid: #1e2433;
  --surface: #252936;
  --surface-dark: #1f232e;
  --surface-hover: #2e3344;
  --text: #e8eaed;
  --text-muted: #9aa0a6;
  --accent: #7caf5e;
  --accent-hover: #8fc76a;
  --accent-dark: #6a9a4d;
  --danger: #d9655c;
  --gold: #e8c547;
  --gold-dark: #c9a83a;
  --radius: 8px;
  --shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
  --glow-accent: 0 0 20px rgba(124, 175, 94, 0.25);
  --glow-gold: 0 0 16px rgba(232, 197, 71, 0.3);
  --border: rgba(255,255,255,0.04);
  --canvas-bg: radial-gradient(ellipse at center, #141824 0%, #0f1118 100%);
}

[data-theme="ocean"] {
  --bg: #0f1a24;
  --bg-mid: #132530;
  --surface: #1a2d3d;
  --surface-dark: #152535;
  --surface-hover: #243d52;
  --text: #d8e8f0;
  --text-muted: #7a9fb0;
  --accent: #3d9db5;
  --accent-hover: #52b5cc;
  --accent-dark: #2d7d92;
  --danger: #e06b6b;
  --gold: #7dd3fc;
  --gold-dark: #5eb8e0;
  --glow-accent: 0 0 20px rgba(61, 157, 181, 0.35);
  --glow-gold: 0 0 16px rgba(125, 211, 252, 0.35);
  --border: rgba(255,255,255,0.06);
  --canvas-bg: radial-gradient(ellipse at center, #0d1620 0%, #080e14 100%);
}

[data-theme="sunset"] {
  --bg: #241a14;
  --bg-mid: #2e2018;
  --surface: #3d2a1f;
  --surface-dark: #322419;
  --surface-hover: #4d3628;
  --text: #f0e4d8;
  --text-muted: #b09a88;
  --accent: #d97850;
  --accent-hover: #e89070;
  --accent-dark: #b85c38;
  --danger: #c44a4a;
  --gold: #f0b050;
  --gold-dark: #d49430;
  --glow-accent: 0 0 20px rgba(217, 120, 80, 0.35);
  --glow-gold: 0 0 16px rgba(240, 176, 80, 0.4);
  --border: rgba(255,255,255,0.05);
  --canvas-bg: radial-gradient(ellipse at center, #1a1210 0%, #0f0c0a 100%);
}

[data-theme="forest"] {
  --bg: #141c18;
  --bg-mid: #1a261f;
  --surface: #243328;
  --surface-dark: #1e2b22;
  --surface-hover: #2f4235;
  --text: #d4e8d8;
  --text-muted: #8aa890;
  --accent: #4a9c5c;
  --accent-hover: #5eb872;
  --accent-dark: #3a7c48;
  --danger: #c55c5c;
  --gold: #b8c45c;
  --gold-dark: #9aa84a;
  --glow-accent: 0 0 20px rgba(74, 156, 92, 0.3);
  --glow-gold: 0 0 16px rgba(184, 196, 92, 0.3);
  --border: rgba(255,255,255,0.04);
  --canvas-bg: radial-gradient(ellipse at center, #0e1612 0%, #080d0a 100%);
}

[data-theme="purple"] {
  --bg: #1a1624;
  --bg-mid: #221c2e;
  --surface: #2d2438;
  --surface-dark: #252030;
  --surface-hover: #3a3048;
  --text: #e8e0f0;
  --text-muted: #a098b0;
  --accent: #9a6fd4;
  --accent-hover: #b08ae8;
  --accent-dark: #7a58b0;
  --danger: #d06078;
  --gold: #d4a0f0;
  --gold-dark: #b080d8;
  --glow-accent: 0 0 20px rgba(154, 111, 212, 0.35);
  --glow-gold: 0 0 16px rgba(212, 160, 240, 0.35);
  --border: rgba(255,255,255,0.05);
  --canvas-bg: radial-gradient(ellipse at center, #141020 0%, #0c0a14 100%);
}

[data-theme="light"] {
  --bg: #e8ecf0;
  --bg-mid: #d8dee6;
  --surface: #f0f4f8;
  --surface-dark: #e4eaf0;
  --surface-hover: #d0d8e0;
  --text: #1c242c;
  --text-muted: #5a6874;
  --accent: #2d8a4e;
  --accent-hover: #38a85e;
  --accent-dark: #246b3d;
  --danger: #c43838;
  --gold: #b8860c;
  --gold-dark: #966a0a;
  --shadow: 0 2px 12px rgba(0, 0, 0, 0.12);
  --glow-accent: 0 0 16px rgba(45, 138, 78, 0.25);
  --glow-gold: 0 0 14px rgba(184, 134, 12, 0.3);
  --border: rgba(0,0,0,0.08);
  --canvas-bg: radial-gradient(ellipse at center, #2a3040 0%, #1a1e28 100%);
}

[data-theme="red"] {
  --bg: #1a1214;
  --bg-mid: #24181a;
  --surface: #2e1e22;
  --surface-dark: #261a1e;
  --surface-hover: #3d282c;
  --text: #f0d8dc;
  --text-muted: #a07880;
  --accent: #c85050;
  --accent-hover: #e06868;
  --accent-dark: #a03838;
  --danger: #e85858;
  --gold: #e8a040;
  --gold-dark: #c88430;
  --glow-accent: 0 0 20px rgba(200, 80, 80, 0.4);
  --glow-gold: 0 0 16px rgba(232, 160, 64, 0.4);
  --border: rgba(255,255,255,0.05);
  --canvas-bg: radial-gradient(ellipse at center, #181012 0%, #0e0a0c 100%);
}

[data-theme="rainbow"] {
  --bg: #1a1418;
  --bg-mid: #1e1820;
  --surface: #2a2230;
  --surface-dark: #241e2a;
  --surface-hover: #362e40;
  --text: #f0e8f0;
  --text-muted: #a090b0;
  --accent: #60c878;
  --accent-hover: #78e090;
  --accent-dark: #48a860;
  --danger: #e06070;
  --gold: #e8c050;
  --gold-dark: #c8a040;
  --glow-accent: 0 0 20px rgba(96, 200, 120, 0.35);
  --glow-gold: 0 0 18px rgba(232, 192, 80, 0.4);
  --border: rgba(255,255,255,0.06);
  --canvas-bg: radial-gradient(ellipse at center, #141018 0%, #0c0810 100%);
}

body[data-theme="rainbow"] {
  background: linear-gradient(135deg, #2a0a18 0%, #2a1810 12%, #2a2a0a 25%, #0a2a18 38%, #0a182a 52%, #18102a 65%, #2a0a2a 78%, #2a0a18 100%);
  background-attachment: fixed;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: "Segoe UI", system-ui, sans-serif;
  background: linear-gradient(160deg, var(--bg) 0%, var(--bg-mid) 40%, var(--bg) 100%);
  color: var(--text);
  min-height: 100vh;
  line-height: 1.5;
}

.game-wrap {
  max-width: 1100px;
  margin: 0 auto;
  padding: 1rem;
}

.hud {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.5rem;
  padding: 0.5rem 1rem;
  background: linear-gradient(180deg, var(--surface) 0%, var(--surface-dark) 100%);
  border-radius: var(--radius);
  margin-bottom: 1rem;
  box-shadow: var(--shadow), 0 1px 0 var(--border);
  border: 1px solid var(--border);
}

.hud-title {
  font-size: 1.1rem;
  font-weight: 700;
  letter-spacing: 0.03em;
  margin-right: 1rem;
  color: var(--gold);
  text-shadow: 0 0 20px rgba(232, 197, 71, 0.3);
}
.hud-item { margin-right: 1rem; }
.hud-item strong { color: var(--accent); }

.btn {
  padding: 0.4rem 0.8rem;
  border: none;
  border-radius: 6px;
  font-size: 0.9rem;
  cursor: pointer;
  background: var(--surface-hover);
  color: var(--text);
  transition: background 0.15s, transform 0.1s;
}

.btn:active { transform: scale(0.98); }
.btn:hover:not(:disabled) { filter: brightness(1.15); transform: translateY(-1px); }
.btn:disabled { opacity: 0.5; cursor: not-allowed; }
.btn-wave {
  background: linear-gradient(180deg, var(--accent) 0%, var(--accent-dark) 100%);
  color: #111;
  font-weight: 600;
  box-shadow: 0 2px 0 rgba(0,0,0,0.2), var(--glow-accent);
}
.btn-wave:hover:not(:disabled) { background: linear-gradient(180deg, var(--accent-hover) 0%, var(--accent) 100%); box-shadow: 0 2px 12px var(--glow-accent); }
.btn-wave.ready { animation: pulse-ready 1.5s ease-in-out infinite; }
@keyframes pulse-ready {
  50% { box-shadow: 0 2px 0 rgba(0,0,0,0.2), 0 0 24px rgba(124, 175, 94, 0.45); }
}
.btn-super {
  background: linear-gradient(180deg, var(--gold) 0%, var(--gold-dark) 100%);
  color: #111;
  font-weight: bold;
  box-shadow: 0 2px 0 rgba(0,0,0,0.2), var(--glow-gold);
}
.btn-super:hover:not(:disabled) { box-shadow: 0 2px 14px var(--glow-gold); }
.btn-shop { background: var(--surface-hover); color: var(--text); }

.main-row {
  display: flex;
  gap: 1rem;
  align-items: flex-start;
}

.tower-panel {
  flex-shrink: 0;
  width: 200px;
  padding: 1rem;
  background: var(--surface);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.tower-panel h2 {
  margin: 0 0 0.75rem 0;
  font-size: 1rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
}

.tower-list { display: flex; flex-direction: column; gap: 0.5rem; margin-bottom: 1rem; }

.tower-list .btn {
  text-align: left;
  display: block;
  padding: 0.5rem;
}

.tower-info, .selected-cell {
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-top: 0.5rem;
}

.selected-cell { display: flex; gap: 0.5rem; flex-wrap: wrap; }
.btn-sell { background: var(--danger); color: #fff; }
.btn-sell:hover:not(:disabled) { filter: brightness(1.1); }

.hidden { display: none !important; }

.canvas-wrap {
  position: relative;
  background: var(--canvas-bg);
  border-radius: var(--radius);
  overflow: hidden;
  box-shadow: var(--shadow), 0 0 0 1px var(--border), inset 0 1px 0 rgba(255,255,255,0.03);
}

#game-canvas { display: block; }

.screen-overlay {
  position: absolute;
  inset: 0;
  background: rgba(0,0,0,0.8);
  display: flex;
  align-items: center;
  justify-content: center;
  backdrop-filter: blur(4px);
}
.screen-overlay:not(.hidden) { animation: overlay-in 0.2s ease-out; }
@keyframes overlay-in {
  from { opacity: 0; }
  to { opacity: 1; }
}

.screen-content {
  text-align: center;
  padding: 2rem;
  background: linear-gradient(180deg, var(--surface) 0%, var(--surface-dark) 100%);
  border-radius: var(--radius);
  max-width: 360px;
  box-shadow: var(--shadow), 0 0 40px rgba(0,0,0,0.4), 0 1px 0 var(--border);
  border: 1px solid var(--border);
  animation: pop-in 0.25s ease-out;
}
@keyframes pop-in {
  from { opacity: 0; transform: scale(0.96) translateY(-8px); }
  to { opacity: 1; transform: scale(1) translateY(0); }
}

.screen-content h3 { margin: 0 0 1rem 0; font-size: 1.5rem; color: var(--gold); }
.screen-content p { margin: 0.5rem 0; color: var(--text-muted); }

.shop-content { max-width: 320px; }
.shop-content h3 { margin-bottom: 0.5rem; color: var(--gold); }
.shop-gold { margin-bottom: 1rem; color: var(--gold); }
.shop-items { display: flex; flex-direction: column; gap: 0.5rem; margin-bottom: 1rem; text-align: left; }
.shop-item .shop-btn { width: 100%; justify-content: center; }
.shop-item .shop-btn:disabled { opacity: 0.5; cursor: not-allowed; }

.level-select-wrap {
  margin-top: 1rem;
  padding: 1rem;
  background: var(--surface);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
}

.level-select-wrap h2 {
  margin: 0 0 0.5rem 0;
  font-size: 0.9rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.level-buttons { display: flex; flex-wrap: wrap; gap: 0.5rem; }

.level-buttons .btn.locked { opacity: 0.6; }
.level-buttons .btn.unlocked {
  background: linear-gradient(180deg, var(--accent) 0%, var(--accent-dark) 100%);
  color: #111;
  font-weight: 500;
  box-shadow: 0 1px 4px rgba(0,0,0,0.25);
}
.level-buttons .btn.unlocked:hover { background: linear-gradient(180deg, var(--accent-hover) 0%, var(--accent) 100%); box-shadow: 0 2px 8px var(--glow-accent); }

.theme-select-wrap {
  margin-top: 0.75rem;
  padding: 0.75rem 1rem;
  background: var(--surface);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
}
.theme-select-wrap h2 {
  margin: 0 0 0.5rem 0;
  font-size: 0.9rem;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}
.theme-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
}
.theme-buttons .btn {
  padding: 0.35rem 0.6rem;
  font-size: 0.8rem;
}
.theme-buttons .btn.active {
  background: var(--accent);
  color: #111;
  box-shadow: var(--glow-accent);
}