/* ============================================
   Tetris PWA — Dark Arcade Style Stylesheet
   ============================================ */

/* --- CSS Custom Properties (Dark Theme Default) --- */
:root {
  --bg-primary: #0f0f1a;
  --bg-secondary: #1a1a2e;
  --bg-tertiary: #16213e;
  --text-primary: #e0e0ff;
  --text-secondary: #a0a0c0;
  --accent: #00d4ff;
  --accent-hover: #00b8e6;
  --danger: #ff4757;
  --success: #2ed573;
  --border-color: #2a2a4a;
  --focus-ring: #00d4ff;
  --shadow-glow: rgba(0, 212, 255, 0.18);
  --btn-primary-bg: #00d4ff;
  --btn-primary-text: #0f0f1a;
  --btn-secondary-bg: #2a2a4a;
  --btn-secondary-text: #e0e0ff;
}

/* Light Theme */
body.light-theme {
  --bg-primary: #eef0f6;
  --bg-secondary: #ffffff;
  --bg-tertiary: #dfe2ec;
  --text-primary: #1a1a2e;
  --text-secondary: #444466;
  --accent: #396afc;
  --accent-hover: #5c7cfa;
  --border-color: #b0b8cc;
  --focus-ring: #396afc;
  --shadow-glow: rgba(57, 106, 252, 0.14);
  --btn-primary-bg: #396afc;
  --btn-primary-text: #ffffff;
  --btn-secondary-bg: #c8ccda;
  --btn-secondary-text: #1a1a2e;
}

/* --- Reset & Base --- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { font-size: 16px; -webkit-text-size-adjust: 100%; }

body {
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  background-color: var(--bg-primary);
  color: var(--text-primary);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  line-height: 1.5;
  overflow-x: hidden;
}

/* Focus */
*:focus-visible { outline: 2px solid var(--focus-ring); outline-offset: 2px; }
canvas:focus-visible { outline-color: var(--accent); outline-width: 3px; box-shadow: 0 0 14px var(--shadow-glow); }

/* --- Header --- */
header {
  width: 100%; max-width: 800px;
  display: flex; justify-content: space-between; align-items: center;
  padding: 1rem 1.5rem .4rem;
}

.logo { height: 48px; width: auto; display: block; }

#themeToggle {
  background: var(--btn-secondary-bg); color: var(--btn-secondary-text);
  border: 1px solid var(--border-color); border-radius: 8px;
  width: 42px; height: 42px; font-size: 1.3rem; cursor: pointer;
  display: flex; align-items: center; justify-content: center;
  transition: background-color .2s, border-color .2s;
}
#themeToggle:hover { background: var(--accent); color: var(--bg-primary); }

/* --- Game Container --- */
.game-container {
  display: flex; gap: 1.5rem;
  padding: .6rem 1rem 0; align-items: flex-start; justify-content: center;
  max-width: 700px; width: 100%;
}

/* Board */
.board-wrapper {
  border: 2px solid var(--border-color); border-radius: 4px;
  overflow: hidden; position: relative;
  box-shadow: 0 0 28px var(--shadow-glow), inset 0 0 10px rgba(0,0,0,.35);
}
#gameCanvas { display: block; background-color: #0a0a14; image-rendering: pixelated; }

/* Side Panel */
.side-panel {
  display: flex; flex-direction: column; gap: .8rem;
  min-width: 150px;
}
.panel-section {
  background: var(--bg-secondary); border: 1px solid var(--border-color);
  border-radius: 8px; padding: .7rem .6rem; text-align: center;
}
.side-panel h2 {
  font-size: .78rem; font-weight: 600; color: var(--text-secondary);
  text-transform: uppercase; letter-spacing: .04em; margin-bottom: .35rem;
}
#nextCanvas { display: block; margin: 0 auto; background-color: #0a0a14; border-radius: 6px; image-rendering: pixelated; }

.stat-value {
  font-size: 2rem; font-weight: 700; color: var(--accent);
  text-shadow: 0 0 12px var(--shadow-glow); font-variant-numeric: tabular-nums;
}

/* Buttons */
.btn {
  display: inline-block; padding: .45rem .8rem; border: none; border-radius: 6px;
  font-size: .88rem; font-weight: 600; cursor: pointer; width: 100%;
  margin-bottom: .4rem; transition: background-color .2s, transform .12s;
}
.btn:active { transform: scale(.97); }
.btn-primary { background-color: var(--btn-primary-bg); color: var(--btn-primary-text); }
.btn-primary:hover:not(:disabled) { background-color: var(--accent-hover); }
.btn-secondary { background-color: var(--btn-secondary-bg); color: var(--btn-secondary-text); }
.btn-secondary:hover:not(:disabled) { background-color: var(--accent); color: var(--bg-primary); }
.btn:disabled { opacity: .4; cursor: not-allowed; transform: none; }

/* Keyboard Help */
.controls-help { max-width: 680px; width: 100%; padding: 1rem 1rem 0; margin-top: .3rem; }
.controls-help h2 { font-size: .9rem; color: var(--text-secondary); text-align: center; margin-bottom: .6rem; text-transform: uppercase; letter-spacing: .04em; }
.keys-grid { display: flex; flex-wrap: wrap; justify-content: center; gap: .45rem 1.2rem; }
.key-row { display: inline-flex; align-items: center; gap: .35rem; font-size: .82rem; color: var(--text-secondary); }
kbd {
  display: inline-block; background: var(--bg-tertiary);
  border: 1px solid var(--border-color); border-radius: 4px;
  padding: .12rem .35rem; font-family: monospace; font-size: .78rem;
  color: var(--accent); min-width: 1.5em; text-align: center;
}

/* Touch Controls */
.touch-controls {
  position: fixed; bottom: 0; left: 0; right: 0;
  display: flex; justify-content: center; gap: .4rem;
  padding: .6rem .8rem; background: var(--bg-secondary);
  border-top: 2px solid var(--border-color); z-index: 10;
}

/* Hide touch controls where physical keys exist */
@media (hover: hover) and (pointer: fine) {
  .touch-controls { display: none; }
}

.touch-btn {
  width: 62px; height: 54px; background: var(--bg-tertiary); color: var(--text-primary);
  border: 2px solid var(--border-color); border-radius: 12px; font-size: 1.4rem;
  display: flex; align-items: center; justify-content: center;
  cursor: pointer; transition: background-color .1s, transform .1s, border-color .15s;
  -webkit-tap-highlight-color: transparent; user-select: none; touch-action: manipulation;
}
.touch-btn:hover { border-color: var(--accent); }
.touch-btn:active, .touch-btn.active-touch {
  background-color: var(--accent); color: #0f0f1a; transform: scale(.93); border-color: var(--accent);
}

@media (hover: none) or (pointer: coarse) { body { padding-bottom: 115px; } }

/* Overlay */
.overlay {
  position: fixed; inset: 0; background: rgba(10,10,20,.92);
  display: flex; align-items: center; justify-content: center; z-index: 100;
}
.overlay.hidden { display: none; }
.overlay-content {
  background: var(--bg-secondary); border: 2px solid var(--accent);
  border-radius: 16px; padding: 2rem 2.4rem; text-align: center;
  max-width: 380px; width: 92%; box-shadow: 0 0 50px var(--shadow-glow);
}
.overlay-content h2 { font-size: 1.6rem; margin-bottom: .6rem; color: var(--accent); }
.overlay-content p { font-size: 1rem; color: var(--text-secondary); margin-bottom: 1.2rem; }

/* Responsive */
@media (max-width: 640px) {
  .game-container { flex-direction: column; align-items: center; }
  .side-panel { flex-wrap: wrap; flex-direction: row; justify-content: center; min-width: auto; max-width: 380px; }
  .panel-section { flex: 1 1 auto; min-width: 75px; }
  .btn { width: auto; }
}