html, body {
  margin: 0;
  height: 100%;
  overflow: hidden;
  background: radial-gradient(1400px 1000px at 50% 40%, #f7faff, #eaf2ff 60%, #dde8ff 100%);
  color: #1a2233;
  font-family: Inter, system-ui, -apple-system, Segoe UI, Roboto, Helvetica, Arial, sans-serif;
}

canvas { display: block; touch-action: none; }

#ui {
  position: fixed;
  inset: 0;
  pointer-events: none; /* let clicks through except controls */
}

#hud {
  position: absolute;
  top: 16px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 16px;
  align-items: center;
  background: rgba(255,255,255,0.7);
  border: 1px solid rgba(0,0,0,0.08);
  padding: 8px 12px;
  border-radius: 10px;
  backdrop-filter: blur(8px);
  box-shadow: 0 10px 30px rgba(0,0,0,0.15);
  pointer-events: auto;
}

#hud .ghost {
  background: transparent;
  color: #0b1222;
  border: 1px solid rgba(0,0,0,0.12);
  padding: 6px 10px;
  border-radius: 8px;
  font-weight: 600;
}

#target {
  font-weight: 700;
}

#controls {
  position: absolute;
  bottom: 16px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  gap: 10px;
  background: rgba(255,255,255,0.72);
  border: 1px solid rgba(0,0,0,0.08);
  padding: 10px 12px;
  border-radius: 12px;
  backdrop-filter: blur(8px);
  box-shadow: 0 10px 30px rgba(0,0,0,0.12);
  pointer-events: auto;
}

#controlsHeader {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.ghost { background: transparent; color: #0b1222; border: 1px solid rgba(0,0,0,0.12); padding: 6px 10px; border-radius: 8px; font-weight: 600; }
#collapseBtn.ghost { display: none; }

#controls input, #controls select {
  min-width: 340px;
  background: rgba(255,255,255,0.95);
  border: 1px solid rgba(0,0,0,0.15);
  color: #0a0f1f;
  padding: 6px 8px;
  border-radius: 8px;
}

#controls input:disabled, #controls select:disabled {
  opacity: 0.6;
}

#controls button {
  background: #2f6feb;
  color: #ffffff;
  border: none;
  padding: 8px 12px;
  border-radius: 8px;
  font-weight: 700;
  cursor: pointer;
}

#musicBtn[aria-pressed="true"] {
  background: #10b981;
}

#orderBtn[aria-pressed="true"] {
  background: #a855f7;
}

#alphabetBtn[aria-pressed="true"] {
  background: #0ea5e9;
}

#upperAgainBtn[aria-pressed="true"] {
  background: #ef4444;
}

#randomAgainBtn[aria-pressed="true"] {
  background: #f59e0b;
}

#complete {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  background: rgba(255,255,255,0.3);
  pointer-events: auto;
}

#complete[hidden] {
  display: none !important;
}

#complete .card {
  background: rgba(255, 255, 255, 0.95);
  border: 1px solid rgba(0,0,0,0.1);
  padding: 28px 30px;
  border-radius: 14px;
  box-shadow: 0 20px 60px rgba(0,0,0,0.4);
  text-align: center;
}

#complete .title {
  font-size: 24px;
  font-weight: 800;
  margin-bottom: 14px;
  color: #0b1222;
}

#complete button {
  background: #2f6feb;
  color: #ffffff;
  border: none;
  padding: 10px 14px;
  border-radius: 10px;
  font-weight: 800;
  cursor: pointer;
}

/* Floating reopen button (mobile) */
#controlsFab {
  position: absolute;
  bottom: calc(12px + env(safe-area-inset-bottom));
  left: 50%;
  transform: translateX(-50%);
  background: #111827;
  color: #ffffff;
  border: none;
  padding: 10px 14px;
  border-radius: 999px;
  font-weight: 700;
  box-shadow: 0 10px 30px rgba(0,0,0,0.25);
  pointer-events: auto;
}

/* Collapsed state hides the sheet */
#controls[data-collapsed="true"] {
  display: none;
}

/* Mobile tweaks */
@media (max-width: 700px) {
  html, body {
    /* Allow dynamic viewport on mobile browsers */
    height: 100%;
  }

  #hud {
    top: calc(10px + env(safe-area-inset-top));
    gap: 10px;
    padding: 6px 10px;
  }

  #controls {
    bottom: calc(10px + env(safe-area-inset-bottom));
    left: 50%;
    transform: translateX(-50%);
    width: calc(100% - 24px);
    max-width: 640px;
    flex-direction: column;
    align-items: stretch;
    gap: 8px;
    padding: 12px;
  }

  #collapseBtn.ghost { display: inline-block; }
  #hud .ghost { padding: 6px 8px; }

  #controls input, #controls select {
    min-width: 0;
    width: 100%;
    font-size: 16px; /* prevent iOS zoom */
    padding: 10px 12px;
  }

  #controls button {
    width: 100%;
    padding: 12px;
    font-size: 16px;
  }

  #complete .card {
    width: calc(100% - 40px);
    padding: 22px 20px;
  }
}