:root {
  --case-bg: #2b2b2e;
  --case-edge: #1a1a1c;
  --key-bg: #3d3d40;
  --key-bg-hover: #4a4a4e;
  --key-bg-active: #55555a;
  --key-text: #f2f2f2;
  --lcd-bg: #12241a;
  --lcd-bg-off: #0a1410;
  --lcd-text: #8ff0b0;
  --gold: #c9a227;
  --blue: #3d7ea6;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  min-height: 100vh;
  font-family: "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: #16161a;
  padding: 20px;
}

.page {
  width: 100%;
  max-width: 720px;
}

.calc {
  background: var(--case-bg);
  border: 1px solid var(--case-edge);
  border-radius: 18px;
  padding: 20px 24px 28px;
  box-shadow: 0 24px 60px rgba(0, 0, 0, 0.5);
}

.calc-title {
  margin: 0 0 16px;
  text-align: center;
  font-size: 1.1rem;
  font-weight: 600;
  color: #dcdcdc;
  letter-spacing: 0.03em;
}

.screen {
  margin-bottom: 20px;
}

.lcd {
  background: var(--lcd-bg);
  border-radius: 8px;
  padding: 10px 16px 14px;
  box-shadow: inset 0 2px 8px rgba(0, 0, 0, 0.6);
}

.annunciators {
  display: flex;
  gap: 14px;
  margin-bottom: 6px;
  min-height: 12px;
}

.ann {
  font-size: 0.62rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  color: #2a3a30;
  transition: color 0.1s ease;
}

.ann.on {
  color: var(--lcd-text);
}

.lcd-display {
  font-family: "Courier New", monospace;
  font-size: 2rem;
  letter-spacing: 0.06em;
  text-align: right;
  color: var(--lcd-text);
  min-height: 2.4rem;
  overflow: hidden;
  white-space: nowrap;
  text-shadow: 0 0 6px rgba(143, 240, 176, 0.35);
}

.lcd-display.lcd-off {
  color: transparent;
  background: var(--lcd-bg-off);
}

.keyboard-scroll {
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.keyboard {
  display: grid;
  grid-template-columns: repeat(8, 1fr);
  grid-auto-rows: 56px;
  gap: 8px;
  min-width: 480px;
}

.key {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  background: var(--key-bg);
  color: var(--key-text);
  border: none;
  border-radius: 8px;
  cursor: pointer;
  padding: 4px 2px 2px;
  box-shadow: 0 3px 0 rgba(0, 0, 0, 0.35);
  transition: background 0.08s ease, transform 0.08s ease, box-shadow 0.08s ease;
}

.key:hover {
  background: var(--key-bg-hover);
}

.key:active,
.key.key-active-press {
  background: var(--key-bg-active);
  transform: translateY(2px);
  box-shadow: 0 1px 0 rgba(0, 0, 0, 0.35);
}

.key-tall {
  flex-direction: column;
}

.key-low {
  align-self: end;
  height: 60%;
  box-shadow: 0 2px 0 rgba(0, 0, 0, 0.35);
}

.key-f,
.key-g {
  font-weight: 700;
}

.key-f {
  color: var(--gold);
}

.key-g {
  color: var(--blue);
}

.key.key-active-prefix {
  outline: 2px solid currentColor;
  outline-offset: -2px;
}

.legend {
  line-height: 1.1;
}

.legend-f {
  font-size: 0.6rem;
  font-weight: 700;
  color: var(--gold);
}

.legend-main {
  font-size: 0.95rem;
  font-weight: 600;
}

.legend-g {
  font-size: 0.6rem;
  font-weight: 700;
  color: var(--blue);
}

.disclaimer {
  margin-top: 12px;
  text-align: center;
  font-size: 0.75rem;
  color: #6b7078;
}

@media (max-width: 560px) {
  .keyboard {
    grid-auto-rows: 46px;
    gap: 6px;
  }

  .legend-main {
    font-size: 0.8rem;
  }

  .lcd-display {
    font-size: 1.5rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .key,
  .ann {
    transition: none;
  }
}