/* TETRIS DUO Styles - Pure CSS, no CDN, no external fonts */
:root {
  --bg-color: #0b0f19;
  --panel-bg: #131b2e;
  --card-bg: #1c2641;
  --border-color: #2b395b;
  --accent-cyan: #06b6d4;
  --accent-blue: #3b82f6;
  --accent-yellow: #eab308;
  --accent-green: #22c55e;
  --accent-red: #ef4444;
  --accent-purple: #a855f7;
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --font-sans: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, 'Liberation Mono', monospace;
}

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

body {
  background-color: var(--bg-color);
  color: var(--text-main);
  font-family: var(--font-sans);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 1.5rem 1rem;
}

header {
  text-align: center;
  margin-bottom: 1.5rem;
}

h1 {
  font-size: 2.25rem;
  font-weight: 900;
  letter-spacing: 0.15em;
  background: linear-gradient(135deg, var(--accent-cyan), var(--accent-purple));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  text-transform: uppercase;
  margin-bottom: 0.25rem;
}

.subtitle {
  color: var(--text-muted);
  font-size: 0.95rem;
  letter-spacing: 0.05em;
}

/* Mode Selection Menu */
.mode-selector {
  display: flex;
  gap: 1rem;
  margin-bottom: 1.5rem;
  flex-wrap: wrap;
  justify-content: center;
}

.btn {
  background-color: var(--card-bg);
  color: var(--text-main);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 0.65rem 1.25rem;
  font-size: 0.95rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.15s ease-in-out;
  display: inline-flex;
  align-items: center;
  gap: 0.5rem;
}

.btn:hover {
  background-color: #273559;
  border-color: var(--accent-cyan);
  transform: translateY(-1px);
}

.btn:active {
  transform: translateY(0);
}

.btn-primary {
  background-color: #2563eb;
  border-color: #3b82f6;
}

.btn-primary:hover {
  background-color: #1d4ed8;
  border-color: #60a5fa;
}

.btn-success {
  background-color: #16a34a;
  border-color: #22c55e;
}

.btn-success:hover {
  background-color: #15803d;
}

.btn.active {
  border-color: var(--accent-cyan);
  background-color: #1e293b;
  box-shadow: 0 0 12px rgba(6, 182, 212, 0.4);
}

/* Signaling Modal / Panel */
.signaling-panel {
  background-color: var(--panel-bg);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 1.5rem;
  width: 100%;
  max-width: 680px;
  margin-bottom: 1.5rem;
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.4);
}

.signaling-panel h3 {
  font-size: 1.15rem;
  margin-bottom: 0.75rem;
  color: var(--accent-cyan);
}

.signaling-step {
  margin-bottom: 1rem;
}

.signaling-step label {
  display: block;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-muted);
  margin-bottom: 0.35rem;
}

.code-box {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 0.5rem;
}

textarea.signaling-text {
  width: 100%;
  height: 68px;
  background-color: #0b0f19;
  border: 1px solid var(--border-color);
  border-radius: 6px;
  color: #e2e8f0;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  padding: 0.5rem;
  resize: none;
  word-break: break-all;
}

textarea.signaling-text:focus {
  outline: none;
  border-color: var(--accent-cyan);
}

.status-badge {
  display: inline-block;
  font-size: 0.8rem;
  padding: 0.25rem 0.6rem;
  border-radius: 9999px;
  font-weight: 600;
  background-color: #334155;
  color: #cbd5e1;
}

.status-badge.connected {
  background-color: rgba(34, 197, 94, 0.2);
  color: #4ade80;
  border: 1px solid rgba(34, 197, 94, 0.4);
}

.status-badge.waiting {
  background-color: rgba(234, 179, 8, 0.2);
  color: #facc15;
  border: 1px solid rgba(234, 179, 8, 0.4);
}

/* Game Arena */
.arena {
  display: flex;
  gap: 2rem;
  justify-content: center;
  align-items: flex-start;
  flex-wrap: wrap;
  margin-bottom: 1.5rem;
}

.player-panel {
  background-color: var(--panel-bg);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 1rem;
  display: flex;
  flex-direction: column;
  align-items: center;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.3);
}

.player-header {
  width: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.75rem;
  padding-bottom: 0.5rem;
  border-bottom: 1px solid var(--border-color);
}

.player-name {
  font-size: 1.1rem;
  font-weight: 700;
  letter-spacing: 0.05em;
}

.board-container {
  display: flex;
  gap: 0.75rem;
  align-items: flex-start;
}

.side-col {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  width: 72px;
}

.stat-box {
  background-color: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: 6px;
  padding: 0.4rem;
  text-align: center;
}

.stat-label {
  font-size: 0.65rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  color: var(--text-muted);
  text-transform: uppercase;
  margin-bottom: 0.2rem;
}

.stat-val {
  font-size: 1rem;
  font-weight: 800;
  font-family: var(--font-mono);
  color: #ffffff;
}

.preview-canvas {
  background-color: #0b0f19;
  border-radius: 4px;
  display: block;
  margin: 0 auto;
}

.board-canvas {
  background-color: #0b0f19;
  border: 2px solid var(--border-color);
  border-radius: 6px;
  display: block;
}

/* Action Controls & Legend */
.actions-bar {
  display: flex;
  gap: 1rem;
  margin-bottom: 1.5rem;
  justify-content: center;
}

.controls-guide {
  background-color: var(--panel-bg);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 1rem 1.5rem;
  max-width: 680px;
  width: 100%;
}

.controls-guide h4 {
  font-size: 0.9rem;
  color: var(--accent-cyan);
  text-transform: uppercase;
  margin-bottom: 0.5rem;
  text-align: center;
}

.key-grids {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
}

.key-list {
  list-style: none;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.key-list li {
  margin-bottom: 0.35rem;
  display: flex;
  justify-content: space-between;
}

kbd {
  background-color: #1e293b;
  border: 1px solid #475569;
  border-radius: 4px;
  padding: 0.15rem 0.4rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: #f1f5f9;
}

/* Toast */
.toast {
  position: fixed;
  bottom: calc(4.5rem + env(safe-area-inset-bottom));
  left: 50%;
  transform: translateX(-50%);
  background-color: #0f172a;
  border: 1px solid var(--accent-cyan);
  color: var(--text-main);
  padding: 0.6rem 1.2rem;
  border-radius: 6px;
  font-size: 0.85rem;
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.5);
  opacity: 0;
  transition: opacity 0.2s ease-in-out;
  pointer-events: none;
  z-index: 1500;
  max-width: 90vw;
  text-align: center;
}

.toast.show {
  opacity: 1;
}

/* Match End Overlay */
.match-overlay {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(11, 15, 25, 0.85);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 2000;
  padding: 1rem;
  animation: fadeIn 0.2s ease-out;
}

.match-modal {
  background: var(--panel-bg);
  border: 2px solid var(--accent-cyan);
  border-radius: 16px;
  padding: 2rem 1.5rem;
  text-align: center;
  max-width: 360px;
  width: 100%;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.6);
}

.match-verdict {
  font-size: 2.2rem;
  font-weight: 900;
  letter-spacing: 0.05em;
  margin-bottom: 0.5rem;
  color: #4ade80;
}

.match-verdict.loser {
  color: var(--accent-red);
}

.match-score {
  font-size: 1.05rem;
  color: var(--text-muted);
  margin-bottom: 1.5rem;
  font-family: var(--font-mono);
}

.match-rematch-btn {
  font-size: 1.1rem;
  padding: 0.75rem 2rem;
  width: 100%;
  justify-content: center;
}

/* Touch Controls Bar (Fixed at bottom) */
.touch-controls {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background-color: rgba(11, 15, 25, 0.95);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-top: 1px solid var(--border-color);
  padding: 0.45rem 0.35rem calc(0.45rem + env(safe-area-inset-bottom)) 0.35rem;
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 0.35rem;
  user-select: none;
  -webkit-user-select: none;
  width: 100%;
  box-sizing: border-box;
}

.touch-btn {
  min-width: 44px;
  min-height: 44px;
  height: 48px;
  flex: 1;
  max-width: 54px;
  border-radius: 8px;
  background-color: #1e293b;
  border: 1px solid #334155;
  color: var(--text-main);
  font-size: 1.25rem;
  font-weight: 700;
  display: flex;
  justify-content: center;
  align-items: center;
  touch-action: manipulation;
  cursor: pointer;
  transition: all 0.1s ease-in-out;
  user-select: none;
  -webkit-user-select: none;
}

.touch-btn.btn-hold {
  font-size: 0.75rem;
  font-weight: 800;
  letter-spacing: 0.05em;
  background-color: #1e2640;
  color: var(--accent-cyan);
}

.touch-btn.btn-harddrop {
  color: var(--accent-yellow);
}

.touch-btn:active,
.touch-btn.pressed {
  background-color: #2563eb;
  border-color: #60a5fa;
  color: #ffffff;
  transform: scale(0.92);
}

/* Mobile Responsive Layout (< 900px) */
@media (max-width: 899px) {
  html, body {
    overflow-x: hidden;
    width: 100%;
    max-width: 100vw;
  }

  body {
    padding: 0.75rem 0.5rem calc(76px + env(safe-area-inset-bottom)) 0.5rem;
  }

  header {
    margin-bottom: 0.75rem;
  }

  h1 {
    font-size: 1.75rem;
  }

  .subtitle {
    font-size: 0.8rem;
  }

  .mode-selector {
    gap: 0.5rem;
    margin-bottom: 0.75rem;
  }

  .mode-selector .btn {
    padding: 0.5rem 0.75rem;
    font-size: 0.85rem;
  }

  .signaling-panel {
    padding: 1rem 0.75rem;
    margin-bottom: 0.75rem;
  }

  .code-box {
    flex-wrap: wrap;
  }

  .code-box .btn {
    padding: 0.5rem 0.75rem;
    font-size: 0.8rem;
  }

  /* Single Column: Own board large, Opponent board small (scaled preview) */
  .arena {
    flex-direction: column;
    align-items: center;
    gap: 0.75rem;
    width: 100%;
    max-width: 100vw;
    margin-bottom: 0.75rem;
  }

  /* Player 1 Panel: Own board (large) */
  #panelP1 {
    width: 100%;
    max-width: 345px;
    padding: 0.5rem;
  }

  #panelP1 .board-container {
    gap: 0.4rem;
    justify-content: center;
    width: 100%;
  }

  #panelP1 .board-canvas {
    width: min(200px, calc(100vw - 130px)) !important;
    height: auto !important;
    aspect-ratio: 1 / 2;
  }

  #panelP1 .side-col {
    width: 48px;
    gap: 0.35rem;
  }

  #panelP1 .stat-box {
    padding: 0.25rem 0.15rem;
  }

  #panelP1 .stat-label {
    font-size: 0.6rem;
  }

  #panelP1 .stat-val {
    font-size: 0.85rem;
  }

  #panelP1 .preview-canvas {
    width: 44px !important;
    height: 40px !important;
  }

  /* Player 2 Panel: Opponent board (small scaled preview) */
  #panelP2 {
    width: auto;
    max-width: 250px;
    padding: 0.4rem 0.6rem;
    background: rgba(19, 27, 46, 0.75);
    border: 1px dashed var(--border-color);
  }

  #panelP2 .player-header {
    margin-bottom: 0.25rem;
    padding-bottom: 0.2rem;
  }

  #panelP2 .player-name {
    font-size: 0.8rem;
    color: var(--text-muted);
  }

  #panelP2 .status-badge {
    font-size: 0.65rem;
    padding: 0.15rem 0.4rem;
  }

  #panelP2 .board-container {
    gap: 0.35rem;
    justify-content: center;
  }

  #panelP2 .board-canvas {
    width: 100px !important;
    height: 200px !important;
  }

  #panelP2 .side-col {
    width: 38px;
    gap: 0.25rem;
  }

  #panelP2 .stat-box {
    padding: 0.15rem;
  }

  #panelP2 .stat-label {
    font-size: 0.5rem;
  }

  #panelP2 .stat-val {
    font-size: 0.7rem;
  }

  #panelP2 .preview-canvas {
    width: 34px !important;
    height: 28px !important;
  }

  .actions-bar {
    margin-bottom: 0.75rem;
  }

  .controls-guide {
    padding: 0.75rem;
    font-size: 0.75rem;
  }

  .key-grids {
    grid-template-columns: 1fr;
    gap: 0.75rem;
  }
}

/* QR Code Pairing Styles */
.qr-pairing-box {
  display: flex;
  flex-direction: column;
  align-items: center;
  background: rgba(15, 23, 42, 0.6);
  border: 1px solid var(--border-color);
  border-radius: 12px;
  padding: 1.25rem;
  margin: 1rem 0;
}

.qr-canvas-wrapper {
  background: #ffffff;
  padding: 10px;
  border-radius: 8px;
  display: inline-flex;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.4);
}

.qr-canvas {
  display: block;
  width: 280px;
  height: 280px;
  max-width: 85vw;
  max-height: 85vw;
  border-radius: 4px;
}

.qr-instruction {
  margin: 0.75rem 0 0.5rem 0;
  font-size: 0.9rem;
  color: var(--text-muted);
  text-align: center;
}

.qr-actions {
  display: flex;
  gap: 0.5rem;
  margin-top: 0.25rem;
  flex-wrap: wrap;
  justify-content: center;
}

.manual-code-details {
  margin: 1rem 0;
  background: rgba(15, 23, 42, 0.3);
  border-radius: 8px;
  padding: 0.5rem 0.75rem;
  border: 1px dashed var(--border-color);
}

.manual-code-details summary {
  cursor: pointer;
  font-size: 0.85rem;
  color: var(--text-muted);
  font-weight: 500;
  outline: none;
}

.tab-ack-notice {
  position: fixed;
  inset: 0;
  background: rgba(11, 15, 25, 0.92);
  backdrop-filter: blur(8px);
  z-index: 10000;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 1.5rem;
}

.tab-ack-modal {
  background: var(--panel-bg);
  border: 2px solid var(--accent-green);
  border-radius: 16px;
  padding: 2rem 1.5rem;
  text-align: center;
  max-width: 400px;
  width: 100%;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.6);
}

.tab-ack-icon {
  font-size: 3rem;
  margin-bottom: 0.75rem;
}

.tab-ack-modal h2 {
  font-size: 1.4rem;
  color: var(--accent-green);
  margin-bottom: 0.5rem;
}

.tab-ack-modal p {
  color: var(--text-muted);
  margin-bottom: 1.25rem;
}

/* Start-Gate Readiness Bar */
.ready-bar {
  display: flex;
  justify-content: center;
  align-items: center;
  margin: 0.5rem 0;
  width: 100%;
}

.btn-ready {
  width: 100%;
  max-width: 240px;
  justify-content: center;
  background-color: var(--card-bg);
  border: 2px solid var(--accent-cyan);
  color: var(--accent-cyan);
  font-size: 1rem;
  font-weight: 700;
  padding: 0.6rem 1rem;
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.2s ease;
}

.btn-ready:hover:not(:disabled) {
  background-color: rgba(6, 182, 212, 0.15);
  box-shadow: 0 0 12px rgba(6, 182, 212, 0.3);
}

.btn-ready:disabled {
  background-color: rgba(34, 197, 94, 0.18);
  border-color: var(--accent-green);
  color: var(--accent-green);
  opacity: 0.85;
  cursor: default;
  box-shadow: 0 0 8px rgba(34, 197, 94, 0.2);
}

/* Room Pairing (Chunk D) */
.room-pairing-box {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 1rem;
}

.room-code-badge {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  background-color: var(--card-bg);
  border: 2px solid var(--accent-cyan);
  border-radius: 10px;
  padding: 0.6rem 1.25rem;
  box-shadow: 0 0 15px rgba(6, 182, 212, 0.2);
}

.room-label {
  font-size: 0.85rem;
  text-transform: uppercase;
  color: var(--text-muted);
  font-weight: 700;
  letter-spacing: 0.05em;
}

.room-code-text {
  font-family: var(--font-mono);
  font-size: 1.6rem;
  font-weight: 900;
  color: #38bdf8;
  letter-spacing: 0.25rem;
}

.room-join-group {
  display: flex;
  gap: 0.5rem;
  width: 100%;
  max-width: 360px;
  margin: 0 auto;
}

.room-code-input {
  flex: 1;
  font-family: var(--font-mono);
  font-size: 1.25rem;
  font-weight: 700;
  letter-spacing: 0.2rem;
  text-align: center;
  text-transform: uppercase;
  padding: 0.6rem 0.75rem;
  background-color: var(--bg-color);
  border: 1px solid var(--border-color);
  border-radius: 8px;
  color: var(--text-main);
  outline: none;
}

.room-code-input:focus {
  border-color: var(--accent-cyan);
  box-shadow: 0 0 10px rgba(6, 182, 212, 0.3);
}

/* Countdown Overlay */
.countdown-overlay {
  position: fixed;
  inset: 0;
  background: rgba(11, 15, 25, 0.82);
  backdrop-filter: blur(6px);
  z-index: 9999;
  display: flex;
  align-items: center;
  justify-content: center;
  pointer-events: none;
}

.countdown-content {
  display: flex;
  align-items: center;
  justify-content: center;
}

.countdown-num {
  font-size: 7rem;
  font-weight: 900;
  color: var(--accent-yellow);
  text-shadow: 0 0 40px rgba(234, 179, 8, 0.6);
  user-select: none;
  animation: countdownPop 0.4s ease-out;
}

.countdown-num.go {
  color: var(--accent-green);
  text-shadow: 0 0 40px rgba(34, 197, 94, 0.7);
}

@keyframes countdownPop {
  0% {
    transform: scale(0.6);
    opacity: 0.2;
  }
  60% {
    transform: scale(1.15);
    opacity: 1;
  }
  100% {
    transform: scale(1);
    opacity: 1;
  }
}

.hidden {
  display: none !important;
}