:root {
  --body-bg: #d9dde3;
  --calc-body: #eef0f3;
  --calc-body-dark: #c7cbd2;
  --screen-bg: #b9c4a9;
  --screen-fg: #1c2b1a;
  --key-num: #ffffff;
  --key-num-text: #23262b;
  --key-fn: #b7c4d6;
  --key-fn-text: #1c2733;
  --key-op: #f0a53d;
  --key-op-text: #3a2200;
  --key-eq: #e2582b;
  --key-eq-text: #ffffff;
  --accent: #7a4de0;
  --shadow: rgba(0, 0, 0, 0.25);
  color-scheme: light;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  min-height: 100vh;
  background: radial-gradient(circle at 50% -10%, #f4f5f7 0%, var(--body-bg) 60%, #babfc7 100%);
  font-family: "Hiragino Sans", "Helvetica Neue", Arial, "Yu Gothic", sans-serif;
  color: #24262b;
  display: flex;
  justify-content: center;
  padding: 24px 12px 60px;
}

.page {
  width: 100%;
  max-width: 1000px;
}

h1 {
  text-align: center;
  font-size: 1.3rem;
  margin: 4px auto 20px;
  max-width: 480px;
}

/* Stacked (narrow screens): calc1 on top, calc2 below.
   Side by side (wide screens, media query further down): calc2 on the
   left, calc1 on the right. flex `order` (not DOM order) controls this so
   the two layouts can disagree about which comes "first". */
.calc-row {
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: 16px;
}
#calc { order: 1; }
#calc2 { order: 2; }

.calc {
  background: linear-gradient(180deg, var(--calc-body), var(--calc-body-dark));
  border-radius: 22px;
  padding: 18px 16px 22px;
  box-shadow: 0 18px 40px var(--shadow), inset 0 1px 0 rgba(255,255,255,0.6);
  user-select: none;
  -webkit-user-select: none;
  touch-action: manipulation;
  width: 100%;
  max-width: 480px;
}

.calc-top {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 4px 10px;
}

.solar {
  display: flex;
  gap: 4px;
}
.solar span {
  width: 14px;
  height: 10px;
  background: linear-gradient(160deg, #2b3350, #0f1526);
  border-radius: 2px;
  box-shadow: inset 0 0 0 1px rgba(255,255,255,0.15);
}

.brand {
  font-weight: 700;
  font-style: italic;
  font-size: 0.95rem;
  letter-spacing: 0.03em;
  color: #3a3f47;
}

.screen {
  background: #8f9c7d;
  border-radius: 10px;
  padding: 10px 14px 14px;
  box-shadow: inset 0 3px 8px rgba(0,0,0,0.35);
  margin-bottom: 14px;
}

.screen-icons {
  display: flex;
  justify-content: space-between;
  align-items: center;
  min-height: 16px;
  margin-bottom: 4px;
}

.icon {
  font-size: 0.62rem;
  font-weight: 700;
  color: #2c3a24;
  opacity: 0;
  letter-spacing: 0.05em;
  transition: opacity 0.15s ease;
}
.icon.active { opacity: 1; }
.icon.note-name {
  font-size: 0.75rem;
  opacity: 1;
  min-height: 1em;
}

.display {
  background: var(--screen-bg);
  color: var(--screen-fg);
  font-family: "Courier New", monospace;
  font-size: 1.4rem;
  text-align: right;
  padding: 4px 2px;
  border-radius: 4px;
  letter-spacing: 0.04em;
  overflow: hidden;
  white-space: nowrap;
  min-height: 1.3em;
}

.calc-count-row {
  display: flex;
  justify-content: center;
  margin-bottom: 14px;
}
.calc-count-btn {
  padding: 8px 16px;
  font-size: 0.8rem;
}

.keys {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 8px;
}

.key {
  border: none;
  border-radius: 10px;
  font-size: 1.1rem;
  font-weight: 700;
  padding: 16px 0;
  cursor: pointer;
  box-shadow: 0 3px 0 rgba(0,0,0,0.25), 0 4px 6px rgba(0,0,0,0.15);
  transform: translateY(0);
  transition: transform 0.05s ease, box-shadow 0.05s ease, filter 0.1s ease;
  position: relative;
}
.key:active,
.key.pressed {
  transform: translateY(3px);
  box-shadow: 0 0 0 rgba(0,0,0,0.25);
  filter: brightness(0.92);
}

.key-fn {
  background: var(--key-fn);
  color: var(--key-fn-text);
  font-size: 0.85rem;
  padding: 12px 0;
}

.key-num {
  background: var(--key-num);
  color: var(--key-num-text);
}

.key-op {
  background: var(--key-op);
  color: var(--key-op-text);
}

.key-eq {
  background: var(--key-eq);
  color: var(--key-eq-text);
}

.key-zero {
  grid-column: 1 / 2;
}

.key-plus {
  grid-row: span 2;
}

.music-mode .key-num,
.music-mode .key-op,
.music-mode .key-eq {
  outline: 2px solid rgba(122, 77, 224, 0.55);
  outline-offset: -2px;
}

.note-label {
  position: absolute;
  top: 3px;
  left: 6px;
  font-size: 0.55rem;
  font-weight: 600;
  opacity: 0;
  color: #7a4de0;
}
.music-mode .note-label {
  opacity: 1;
}

.key-hint {
  position: absolute;
  top: 3px;
  right: 6px;
  font-size: 0.55rem;
  font-weight: 600;
  color: #5a6270;
}

.legend {
  max-width: 480px;
  margin: 26px auto 0;
  font-size: 0.85rem;
  line-height: 1.6;
  color: #33363c;
}
.legend summary {
  cursor: pointer;
  font-size: 1rem;
  font-weight: 700;
  margin-bottom: 8px;
}
.legend ul {
  padding-left: 1.2em;
  margin: 0 0 12px;
}
.legend code {
  background: rgba(0,0,0,0.06);
  padding: 1px 5px;
  border-radius: 4px;
}
.legend .note {
  font-size: 0.75rem;
  color: #6b6f76;
}

@media (max-width: 380px) {
  .display { font-size: 1.1rem; }
  .key { font-size: 1rem; padding: 14px 0; }
}

/* Enough width for both calculators (480px each + gap) to sit side by side. */
@media (min-width: 1000px) {
  .calc-row {
    flex-direction: row;
    flex-wrap: wrap;
  }
  #calc2 { order: 1; }
  #calc { order: 2; }
}