:root {
  --bg-primary: #0a0a0f;
  --bg-secondary: #14141f;
  --bg-tertiary: #1e1e2e;
  --text-primary: #ffffff;
  --text-secondary: #a0a0b0;
  --text-muted: #606070;
  --accent: #00d4ff;
  --accent-secondary: #00ff88;
  --danger: #ff4466;
  --focus-ring: #00d4ff;
  --focus-glow: rgba(0, 212, 255, 0.4);
  --radius-md: 12px;
  --green: #00ff88;
  --red: #ff4466;
  --yellow: #ffcc00;
  --blue: #00d4ff;
}

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

html, body {
  width: 600px;
  height: 600px;
  overflow: hidden;
  background: #000;
  color: var(--text-primary);
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  letter-spacing: 0.02em;
}

#app { width: 100%; height: 100%; position: relative; }

.screen {
  width: 100%;
  height: 100%;
  position: absolute;
  top: 0;
  left: 0;
  display: flex;
  flex-direction: column;
}

.screen.hidden { display: none; }

.focusable {
  transition: all 0.15s ease;
  border: 2px solid transparent;
  cursor: pointer;
  outline: none;
}

.focusable:focus {
  border-color: var(--focus-ring);
  box-shadow: 0 0 20px var(--focus-glow);
}

.hidden { display: none !important; }

/* ===== Home Screen ===== */
.home-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 40px;
  gap: 24px;
}

.title-dots {
  display: flex;
  gap: 14px;
  margin-bottom: 8px;
}

.dot {
  width: 18px;
  height: 18px;
  border-radius: 50%;
  display: inline-block;
  animation: pulse 2.4s ease-in-out infinite;
}

.dot-g { background: var(--green); box-shadow: 0 0 14px var(--green); animation-delay: 0s; }
.dot-r { background: var(--red); box-shadow: 0 0 14px var(--red); animation-delay: 0.3s; }
.dot-y { background: var(--yellow); box-shadow: 0 0 14px var(--yellow); animation-delay: 0.6s; }
.dot-b { background: var(--blue); box-shadow: 0 0 14px var(--blue); animation-delay: 0.9s; }

@keyframes pulse {
  0%, 100% { opacity: 0.5; transform: scale(1); }
  50% { opacity: 1; transform: scale(1.15); }
}

.title {
  font-size: 88px;
  font-weight: 800;
  letter-spacing: 0.18em;
  line-height: 1;
  background: linear-gradient(135deg, var(--green), var(--blue));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.subtitle {
  font-size: 18px;
  color: var(--text-secondary);
  letter-spacing: 0.3em;
  text-transform: uppercase;
  margin-bottom: 12px;
}

.menu {
  display: flex;
  flex-direction: column;
  gap: 14px;
  width: 320px;
}

.menu-btn {
  height: 64px;
  background: var(--bg-secondary);
  color: var(--text-primary);
  font-size: 22px;
  font-weight: 600;
  border-radius: var(--radius-md);
  letter-spacing: 0.05em;
  font-family: inherit;
}

.menu-btn:focus {
  background: var(--bg-tertiary);
  transform: scale(1.02);
}

.highscore {
  margin-top: 16px;
  color: var(--text-secondary);
  font-size: 16px;
  letter-spacing: 0.12em;
}

.highscore span {
  color: var(--accent);
  font-weight: 700;
  font-size: 18px;
}

/* ===== Game Screen ===== */
.game-hud {
  height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 20px;
  background: var(--bg-primary);
  border-bottom: 1px solid var(--bg-tertiary);
}

.hud-item {
  display: flex;
  flex-direction: column;
  min-width: 90px;
}

.hud-left { align-items: flex-start; }
.hud-right { align-items: flex-end; }

.hud-label {
  font-size: 11px;
  color: var(--text-muted);
  letter-spacing: 0.2em;
  font-weight: 600;
}

.hud-value {
  font-size: 26px;
  font-weight: 700;
  color: var(--text-primary);
}

.hud-status {
  font-size: 18px;
  font-weight: 700;
  letter-spacing: 0.18em;
  color: var(--accent);
  text-transform: uppercase;
  transition: color 0.2s ease;
}

.hud-status.your-turn { color: var(--accent-secondary); }
.hud-status.correct { color: var(--accent-secondary); }
.hud-status.wrong { color: var(--danger); }

.pads {
  flex: 1;
  display: grid;
  grid-template-columns: 1fr 1fr 1fr;
  grid-template-rows: 1fr 1fr 1fr;
  gap: 12px;
  padding: 16px;
}

.pad {
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0.45;
  transition: opacity 0.08s ease, transform 0.08s ease, box-shadow 0.08s ease;
  position: relative;
}

.pad-arrow {
  font-size: 56px;
  color: rgba(0, 0, 0, 0.55);
  font-weight: 700;
  text-shadow: 0 1px 2px rgba(255, 255, 255, 0.15);
}

.pad-green { grid-column: 2; grid-row: 1; background: var(--green); }
.pad-blue  { grid-column: 1; grid-row: 2; background: var(--blue); }
.pad-red   { grid-column: 3; grid-row: 2; background: var(--red); }
.pad-yellow{ grid-column: 2; grid-row: 3; background: var(--yellow); }

.pad.active {
  opacity: 1;
  transform: scale(1.04);
}

.pad-green.active  { box-shadow: 0 0 40px var(--green), inset 0 0 20px rgba(255,255,255,0.3); }
.pad-blue.active   { box-shadow: 0 0 40px var(--blue),  inset 0 0 20px rgba(255,255,255,0.3); }
.pad-red.active    { box-shadow: 0 0 40px var(--red),   inset 0 0 20px rgba(255,255,255,0.3); }
.pad-yellow.active { box-shadow: 0 0 40px var(--yellow),inset 0 0 20px rgba(255,255,255,0.3); }

.pad.wrong {
  background: var(--danger) !important;
  opacity: 0.9;
  animation: shake 0.4s ease;
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  20% { transform: translateX(-6px); }
  40% { transform: translateX(6px); }
  60% { transform: translateX(-4px); }
  80% { transform: translateX(4px); }
}

.pad-center {
  grid-column: 2;
  grid-row: 2;
  background: var(--bg-secondary);
  border-radius: var(--radius-md);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  border: 2px solid var(--bg-tertiary);
}

.round-num {
  font-size: 56px;
  font-weight: 800;
  color: var(--text-primary);
  line-height: 1;
}

.round-label {
  font-size: 11px;
  color: var(--text-muted);
  letter-spacing: 0.2em;
  margin-top: 4px;
  font-weight: 600;
}

/* ===== Game Over Screen ===== */
.gameover-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 40px;
  gap: 28px;
}

.over-title {
  font-size: 48px;
  font-weight: 800;
  letter-spacing: 0.15em;
  color: var(--danger);
  text-shadow: 0 0 30px rgba(255, 68, 102, 0.4);
}

.over-stats {
  display: flex;
  align-items: center;
  gap: 32px;
  background: var(--bg-secondary);
  padding: 20px 36px;
  border-radius: var(--radius-md);
}

.stat {
  display: flex;
  flex-direction: column;
  align-items: center;
  min-width: 100px;
}

.stat-divider {
  width: 1px;
  height: 56px;
  background: var(--bg-tertiary);
}

.stat-label {
  font-size: 11px;
  color: var(--text-muted);
  letter-spacing: 0.2em;
  font-weight: 600;
}

.stat-value {
  font-size: 44px;
  font-weight: 800;
  color: var(--text-primary);
  line-height: 1.1;
}

.over-message {
  font-size: 18px;
  color: var(--text-secondary);
  letter-spacing: 0.05em;
}

/* ===== How to Play Screen ===== */
.howto-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 32px 40px;
  gap: 20px;
}

.howto-title {
  font-size: 36px;
  font-weight: 800;
  letter-spacing: 0.1em;
  margin-bottom: 8px;
}

.howto-steps {
  display: flex;
  flex-direction: column;
  gap: 12px;
  width: 100%;
  max-width: 440px;
}

.step {
  display: flex;
  align-items: center;
  gap: 18px;
  background: var(--bg-secondary);
  padding: 14px 20px;
  border-radius: var(--radius-md);
}

.step-num {
  width: 38px;
  height: 38px;
  border-radius: 50%;
  background: var(--bg-tertiary);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 18px;
  color: var(--accent);
  flex-shrink: 0;
}

.step-text {
  font-size: 17px;
  color: var(--text-primary);
}

.dpad-legend {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px 28px;
  background: var(--bg-secondary);
  padding: 14px 24px;
  border-radius: var(--radius-md);
}

.legend-row {
  display: flex;
  align-items: center;
  gap: 12px;
}

.legend-arrow {
  font-size: 22px;
  font-weight: 700;
  width: 24px;
  text-align: center;
}

.ar-g { color: var(--green); }
.ar-r { color: var(--red); }
.ar-y { color: var(--yellow); }
.ar-b { color: var(--blue); }

.legend-text {
  font-size: 15px;
  color: var(--text-secondary);
}