/* ── Reset & Base ─────────────────────────────────────────────── */

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

:root {
  --bg: #080c18;
  --surface: #0e1525;
  --surface-2: #141d30;
  --border: #1e2d45;
  --text: #cbd5e1;
  --text-dim: #64748b;
  --accent: #4a9eff;
  --gold: #fbbf24;
  --red: #ef4444;
  --green: #4ade80;
  --font: 'Rajdhani', sans-serif;
  --mono: 'Share Tech Mono', monospace;
  --sidebar-w: 240px;
  --hud-h: 48px;
}

html, body {
  height: 100%;
  overflow: hidden;
  background: var(--bg);
  color: var(--text);
  font-family: var(--font);
  font-size: 14px;
  -webkit-font-smoothing: antialiased;
}

/* ── Layout ───────────────────────────────────────────────────── */

#app {
  display: flex;
  flex-direction: column;
  height: 100vh;
}

#hud {
  height: var(--hud-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 16px;
  background: var(--surface);
  border-bottom: 1px solid var(--border);
  gap: 12px;
  flex-shrink: 0;
  z-index: 10;
}

#main {
  display: flex;
  flex: 1;
  overflow: hidden;
}

#game-area {
  flex: 1;
  position: relative;
  background: #060a14;
  overflow: hidden;
}

#game-area canvas {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  max-width: 100%;
  max-height: 100%;
  image-rendering: auto;
}

#sidebar {
  width: var(--sidebar-w);
  background: var(--surface);
  border-left: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  overflow-y: auto;
  flex-shrink: 0;
}

#sidebar section {
  padding: 14px;
  border-bottom: 1px solid var(--border);
}

/* ── HUD ──────────────────────────────────────────────────────── */

.hud-group {
  display: flex;
  align-items: center;
  gap: 18px;
}

.hud-item {
  display: flex;
  align-items: center;
  gap: 6px;
}

.hud-icon {
  font-size: 16px;
}

.hud-item.lives .hud-icon { color: var(--red); }
.hud-item.gold .hud-icon { color: var(--gold); }
.hud-item.wave .hud-icon { color: var(--accent); }
.hud-item.score .hud-icon { color: var(--green); }

.hud-label {
  font-size: 10px;
  font-weight: 600;
  color: var(--text-dim);
  letter-spacing: 1px;
}

.hud-val {
  font-family: var(--mono);
  font-size: 16px;
  font-weight: 700;
  min-width: 40px;
}

.hud-item.lives .hud-val { color: var(--red); }
.hud-item.gold .hud-val { color: var(--gold); }

/* ── Controls ─────────────────────────────────────────────────── */

.controls button {
  background: var(--surface-2);
  border: 1px solid var(--border);
  color: var(--text-dim);
  width: 32px;
  height: 32px;
  border-radius: 6px;
  cursor: pointer;
  font-size: 14px;
  transition: all 0.15s;
}

.controls button:hover {
  background: var(--border);
  color: var(--text);
}

.controls button.active {
  background: var(--accent);
  color: #fff;
  border-color: var(--accent);
}

/* ── Perf Monitor ─────────────────────────────────────────────── */

.perf {
  font-family: var(--mono);
  font-size: 12px;
  gap: 10px !important;
}

#fps-val { color: var(--green); }
.entity-count { color: var(--text-dim); font-size: 11px; }

/* ── Sidebar ──────────────────────────────────────────────────── */

#tower-shop h3 {
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 2px;
  color: var(--text-dim);
  margin-bottom: 10px;
}

#tower-shop .hint {
  font-weight: 400;
  font-size: 10px;
  color: var(--text-dim);
  opacity: 0.6;
}

.tower-btn {
  display: grid;
  grid-template-columns: 20px 1fr auto;
  grid-template-rows: auto auto;
  gap: 0 8px;
  width: 100%;
  padding: 8px 10px;
  margin-bottom: 4px;
  background: var(--surface-2);
  border: 1px solid var(--border);
  border-radius: 6px;
  cursor: pointer;
  text-align: left;
  color: var(--text);
  font-family: var(--font);
  font-size: 13px;
  transition: all 0.15s;
}

.tower-btn:hover {
  border-color: var(--accent);
  background: rgba(74, 158, 255, 0.08);
}

.tower-btn:not(.affordable) {
  opacity: 0.45;
}

.tower-swatch {
  grid-row: 1 / 3;
  width: 16px;
  height: 16px;
  border-radius: 3px;
  align-self: center;
}

.tower-name {
  font-weight: 600;
  font-size: 13px;
}

.tower-cost {
  font-family: var(--mono);
  color: var(--gold);
  font-size: 12px;
}

.tower-desc {
  grid-column: 2 / 4;
  font-size: 10px;
  color: var(--text-dim);
}

/* ── Tower Info Panel ─────────────────────────────────────────── */

#tower-info h3 {
  font-size: 15px;
  font-weight: 700;
  margin-bottom: 8px;
}

.stat-row {
  display: flex;
  justify-content: space-between;
  padding: 3px 0;
  font-size: 12px;
  border-bottom: 1px solid rgba(255,255,255,0.04);
}

.stat-row span:last-child {
  font-family: var(--mono);
  color: var(--accent);
}

.info-actions {
  display: flex;
  gap: 8px;
  margin-top: 10px;
}

.action-btn {
  flex: 1;
  padding: 7px 0;
  border: 1px solid var(--border);
  border-radius: 6px;
  background: var(--surface-2);
  color: var(--text);
  font-family: var(--font);
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s;
}

.action-btn.upgrade:hover:not(:disabled) {
  border-color: var(--green);
  background: rgba(74, 222, 128, 0.1);
}

.action-btn.sell:hover {
  border-color: var(--red);
  background: rgba(239, 68, 68, 0.1);
}

.action-btn:disabled {
  opacity: 0.4;
  cursor: default;
}

/* ── Wave Section ─────────────────────────────────────────────── */

#wave-preview {
  display: flex;
  flex-wrap: wrap;
  gap: 4px;
  margin-bottom: 10px;
  min-height: 24px;
}

.preview-tag {
  font-size: 10px;
  padding: 2px 6px;
  border-radius: 4px;
  border: 1px solid;
  background: rgba(0,0,0,0.3);
  font-family: var(--mono);
}

.wave-btn {
  width: 100%;
  padding: 10px;
  background: linear-gradient(135deg, #1a6bff, #0044cc);
  border: none;
  border-radius: 8px;
  color: #fff;
  font-family: var(--font);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 1px;
  cursor: pointer;
  transition: all 0.2s;
}

.wave-btn:hover:not(:disabled) {
  transform: translateY(-1px);
  box-shadow: 0 4px 15px rgba(26, 107, 255, 0.3);
}

.wave-btn:disabled {
  background: var(--surface-2);
  color: var(--text-dim);
  cursor: default;
  transform: none;
  box-shadow: none;
}

/* ── Stress Test ──────────────────────────────────────────────── */

.stress-btn {
  width: 100%;
  padding: 8px;
  background: var(--surface-2);
  border: 1px solid #7c3aed;
  border-radius: 6px;
  color: #a855f7;
  font-family: var(--font);
  font-size: 12px;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s;
}

.stress-btn:hover {
  background: rgba(124, 58, 237, 0.15);
  box-shadow: 0 0 12px rgba(124, 58, 237, 0.2);
}

/* ── Overlay ──────────────────────────────────────────────────── */

#overlay {
  position: fixed;
  inset: 0;
  background: rgba(4, 6, 14, 0.88);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 100;
  backdrop-filter: blur(8px);
  transition: opacity 0.3s;
}

#overlay.hidden {
  display: none;
}

#overlay-box {
  text-align: center;
  padding: 48px 60px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 16px;
  box-shadow: 0 24px 80px rgba(0,0,0,0.6);
  max-width: 440px;
}

#overlay-title {
  font-size: 36px;
  font-weight: 700;
  letter-spacing: 4px;
  background: linear-gradient(135deg, var(--accent), #a855f7);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 12px;
}

#overlay-msg {
  color: var(--text-dim);
  font-size: 14px;
  margin-bottom: 28px;
  line-height: 1.5;
}

#overlay-btns {
  display: flex;
  justify-content: center;
  gap: 12px;
}

.overlay-btn {
  padding: 12px 32px;
  background: linear-gradient(135deg, var(--accent), #3b82f6);
  border: none;
  border-radius: 8px;
  color: #fff;
  font-family: var(--font);
  font-size: 16px;
  font-weight: 700;
  letter-spacing: 2px;
  cursor: pointer;
  transition: all 0.2s;
}

.overlay-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(74, 158, 255, 0.35);
}

/* ── Utility ──────────────────────────────────────────────────── */

.hidden { display: none !important; }

/* Scrollbar */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: var(--surface); }
::-webkit-scrollbar-thumb { background: var(--border); border-radius: 3px; }