* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  -webkit-tap-highlight-color: transparent;
  -webkit-touch-callout: none;
}

html,
body {
  position: fixed;
  inset: 0;
  width: 100%;
  height: 100%;
  overflow: hidden;
  overscroll-behavior: none;
  touch-action: none;
  background-color: #070914;
  color: #e9f0ff;
  font-family: system-ui, -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto,
    sans-serif;
  user-select: none;
  -webkit-user-select: none;
}

#app-shell {
  position: relative;
  display: flex;
  flex-direction: column;
  width: 100%;
  height: 100%;
  overflow: hidden;
  padding-top: env(safe-area-inset-top);
}

.top-bar {
  flex: 0 0 auto;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem 0.75rem;
  padding: 0.55rem max(0.9rem, env(safe-area-inset-right)) 0.55rem
    max(0.9rem, env(safe-area-inset-left));
  background: rgba(12, 16, 33, 0.94);
  border-bottom: 1px solid rgba(110, 150, 255, 0.2);
  z-index: 10;
}

.brand {
  display: flex;
  align-items: center;
  min-width: 0;
}

.brand h1 {
  font-size: 1rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  color: #f0f6ff;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.controls {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.45rem;
}

.ctrl-btn {
  appearance: none;
  border: 1px solid rgba(130, 170, 255, 0.35);
  background: rgba(30, 40, 75, 0.75);
  color: #dce8ff;
  padding: 0.34rem 0.7rem;
  border-radius: 6px;
  font-size: 0.8rem;
  font-weight: 600;
  cursor: pointer;
  white-space: nowrap;
  touch-action: manipulation;
  transition: background 0.15s ease, border-color 0.15s ease;
}

.ctrl-btn:hover {
  background: rgba(48, 65, 118, 0.85);
}

.ctrl-btn.active {
  background: rgba(20, 185, 155, 0.28);
  border-color: rgba(45, 240, 200, 0.75);
  color: #7affdf;
}

.control-group {
  display: flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.78rem;
  color: #b8caef;
  background: rgba(20, 27, 52, 0.75);
  padding: 0.24rem 0.5rem;
  border-radius: 6px;
  border: 1px solid rgba(110, 150, 255, 0.2);
  white-space: nowrap;
}

.control-group input[type='range'] {
  width: 80px;
  accent-color: #26e6ff;
  cursor: pointer;
  touch-action: pan-x;
}

.control-group select {
  background: #10172f;
  color: #e9f0ff;
  border: 1px solid rgba(120, 160, 255, 0.35);
  border-radius: 4px;
  padding: 0.15rem 0.35rem;
  font-size: 0.78rem;
  touch-action: manipulation;
}

.error-banner {
  flex: 0 0 auto;
  background: #4e1222;
  border-bottom: 1px solid #ff4d6d;
  color: #ffd6de;
  padding: 0.45rem 0.8rem;
  font-size: 0.8rem;
  font-family: ui-monospace, SFMono-Regular, Menlo, monospace;
  z-index: 30;
}

.visualizer-stage {
  position: relative;
  flex: 1 1 auto;
  min-height: 100px;
  width: 100%;
  overflow: hidden;
  touch-action: none;
}

#visualizer-canvas {
  display: block;
  width: 100%;
  height: 100%;
  touch-action: none;
}

.keyboard-section {
  flex: 0 0 auto;
  height: clamp(140px, 27%, 240px);
  display: flex;
  flex-direction: column;
  background: #0b0e1d;
  border-top: 2px solid rgba(80, 130, 255, 0.3);
  padding: 0.25rem max(0.4rem, env(safe-area-inset-right))
    max(0.4rem, env(safe-area-inset-bottom))
    max(0.4rem, env(safe-area-inset-left));
  touch-action: none;
}

.keyboard-hint {
  text-align: center;
  font-size: 0.72rem;
  color: #8ea4d2;
  margin-bottom: 0.25rem;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.piano-keyboard {
  position: relative;
  flex: 1 1 auto;
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  touch-action: none;
  user-select: none;
  -webkit-user-select: none;
}

.piano-key {
  position: absolute;
  top: 0;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  align-items: center;
  padding-bottom: 0.4rem;
  border-radius: 0 0 6px 6px;
  cursor: pointer;
  touch-action: none;
  user-select: none;
  -webkit-user-select: none;
  transition: transform 0.04s ease, background 0.05s ease, box-shadow 0.05s ease;
}

.white-key {
  height: 100%;
  background: linear-gradient(180deg, #e7eefb 0%, #ffffff 85%, #d5e0f5 100%);
  border: 1px solid #1a233d;
  box-shadow: inset 0 -4px 0 rgba(160, 180, 215, 0.6);
  color: #1c2541;
  z-index: 1;
}

.white-key.active {
  background: linear-gradient(180deg, #74f9ff 0%, #37d5ff 100%);
  box-shadow: 0 0 14px rgba(55, 213, 255, 0.75),
    inset 0 -2px 0 rgba(15, 95, 135, 0.5);
  transform: translateY(2px);
}

.black-key {
  height: 60%;
  background: linear-gradient(180deg, #252d47 0%, #101526 88%, #070a14 100%);
  border: 1px solid #05070f;
  border-radius: 0 0 4px 4px;
  box-shadow: 0 3px 6px rgba(0, 0, 0, 0.55),
    inset 0 -3px 0 rgba(255, 255, 255, 0.08);
  color: #d6e4ff;
  z-index: 2;
  padding-bottom: 0.25rem;
}

.black-key.active {
  background: linear-gradient(180deg, #ff55b8 0%, #d41c8a 100%);
  box-shadow: 0 0 14px rgba(255, 85, 184, 0.8);
  transform: translateY(2px);
}

.key-shortcut {
  font-size: 0.75rem;
  font-weight: 700;
  line-height: 1.1;
  padding: 0.08rem 0.26rem;
  border-radius: 4px;
  background: rgba(15, 25, 50, 0.12);
  margin-bottom: 0.15rem;
  pointer-events: none;
}

.black-key .key-shortcut {
  background: rgba(255, 255, 255, 0.12);
  font-size: 0.66rem;
}

.key-note {
  font-size: 0.62rem;
  opacity: 0.72;
  pointer-events: none;
}

.start-overlay {
  position: absolute;
  inset: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: center;
  background: rgba(7, 9, 20, 0.82);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  cursor: pointer;
  touch-action: manipulation;
}

.start-overlay[hidden] {
  display: none;
}

.start-card {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.55rem;
  padding: 1.75rem 2.5rem;
  border-radius: 16px;
  background: rgba(18, 25, 52, 0.95);
  border: 1px solid rgba(70, 215, 255, 0.45);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.6),
    0 0 28px rgba(38, 230, 255, 0.2);
  text-align: center;
  transition: transform 0.15s ease, border-color 0.15s ease;
}

.start-overlay:hover .start-card {
  transform: scale(1.03);
  border-color: rgba(70, 215, 255, 0.8);
}

.start-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 56px;
  height: 56px;
  border-radius: 50%;
  background: linear-gradient(135deg, #26e6ff 0%, #ff47b6 100%);
  color: #070914;
  font-size: 1.5rem;
  padding-left: 4px;
  box-shadow: 0 0 20px rgba(38, 230, 255, 0.5);
}

.start-card h2 {
  font-size: 1.25rem;
  font-weight: 600;
  color: #ffffff;
}

.start-card p {
  font-size: 0.85rem;
  color: #9ab0dc;
}

@media (max-width: 720px) {
  .top-bar {
    padding: 0.35rem max(0.5rem, env(safe-area-inset-right)) 0.35rem
      max(0.5rem, env(safe-area-inset-left));
    gap: 0.3rem;
  }

  .brand h1 {
    font-size: 0.85rem;
  }

  .controls {
    gap: 0.28rem;
  }

  .ctrl-btn {
    padding: 0.24rem 0.5rem;
    font-size: 0.72rem;
  }

  .control-group {
    padding: 0.16rem 0.35rem;
    font-size: 0.7rem;
    gap: 0.22rem;
  }

  .control-group input[type='range'] {
    width: 58px;
  }

  .tone-label {
    display: none;
  }

  .control-group select {
    font-size: 0.72rem;
    padding: 0.1rem 0.2rem;
    max-width: 115px;
  }

  .keyboard-hint {
    display: none;
  }

  .keyboard-section {
    height: clamp(130px, 28%, 195px);
  }

  .key-shortcut {
    display: none;
  }

  .key-note {
    font-size: 0.5rem;
  }

  .black-key .key-note {
    display: none;
  }
}

@media (max-height: 480px) {
  .top-bar {
    padding: 0.25rem max(0.5rem, env(safe-area-inset-right)) 0.25rem
      max(0.5rem, env(safe-area-inset-left));
  }

  .keyboard-hint {
    display: none;
  }

  .keyboard-section {
    height: clamp(105px, 34%, 145px);
  }
}