:root {
  --piano-container-bg:
    radial-gradient(circle at 50% 32%, #171b22 0%, #12171e 54%, #0d1218 100%);
  --piano-container-shadow:
    0 14px 30px rgba(0, 0, 0, 0.5),
    0 2px 8px rgba(0, 0, 0, 0.3);
  --piano-container-border:
    1px solid rgba(255, 255, 255, 0.06);
  --piano-container-radius: 14px;

  --piano-white-bg:
    linear-gradient(to bottom, #ffffff 0%, #f0f3f8 56%, #e4e9f2 100%);
  --piano-white-border:
    1px solid rgba(18, 24, 34, 0.24);
  --piano-white-shadow-inner:
    inset 0 1px 0 rgba(255, 255, 255, 0.96),
    inset 0 -1px 2px rgba(12, 18, 28, 0.12),
    0 1px 3px rgba(0, 0, 0, 0.14);
  --piano-white-label-color:
    rgba(20, 27, 38, 0.62);

  --piano-black-bg:
    linear-gradient(to bottom, #252a31 0%, #1b2027 52%, #12171d 100%);
  --piano-black-shadow-inner:
    inset 0 1px 0 rgba(255, 255, 255, 0.08),
    inset 0 -1px 2px rgba(0, 0, 0, 0.62),
    0 2px 5px rgba(0, 0, 0, 0.56);
  --piano-black-label-color:
    rgba(240, 245, 252, 0.86);
}