:root {
  --bg: #0d0b24;
  --bg-2: #17143a;
  --card: #1d1946;
  --line: #2f2a66;
  --text: #ece9ff;
  --muted: #9a94c9;
  --mana: #4f8dff;
  --mana-2: #8a5cff;
  --key: #241f55;
  --key-fn: #2e2862;
  --op: #3a2f86;
  --danger: #ff5a7a;
  --ok: #4fe0b0;
  color-scheme: dark;
}

* { box-sizing: border-box; -webkit-tap-highlight-color: transparent; }

html, body { height: 100%; margin: 0; }

body {
  background: radial-gradient(120% 70% at 50% 0%, #241e5c 0%, var(--bg) 60%) fixed, var(--bg);
  color: var(--text);
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  overscroll-behavior: none;
  user-select: none;
  -webkit-user-select: none;
}

.app {
  height: 100dvh;
  max-width: 480px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: calc(env(safe-area-inset-top) + 16px) 16px calc(env(safe-area-inset-bottom) + 16px);
}

.stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 10px;
}

.field {
  display: flex;
  flex-direction: column;
  gap: 4px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 14px;
  padding: 8px 12px;
}
.field span { font-size: 12px; color: var(--muted); letter-spacing: .02em; }
.field input {
  width: 100%;
  background: transparent;
  border: 0;
  outline: 0;
  color: var(--text);
  font: 600 24px/1.1 ui-rounded, system-ui, sans-serif;
  font-variant-numeric: tabular-nums;
  padding: 0;
  pointer-events: none;
}

.field.remaining {
  grid-column: 1 / -1;
  background: linear-gradient(135deg, #1f2a6e, #2b1d6e);
  border-color: #4a46a8;
}
.field.remaining input { font-size: 34px; color: #bfe0ff; }
.field.remaining.low input { color: #ffb36b; }
.field.remaining.empty input { color: var(--danger); }

.bar {
  grid-column: 1 / -1;
  height: 8px;
  border-radius: 99px;
  background: var(--bg-2);
  overflow: hidden;
}
#bar-fill {
  height: 100%;
  width: 0%;
  background: linear-gradient(90deg, var(--mana), var(--mana-2));
  box-shadow: 0 0 12px var(--mana);
  transition: width .25s ease;
}

.display {
  flex: 1;
  min-height: 56px;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  align-items: flex-end;
  gap: 4px;
  padding: 0 4px;
}
.expr {
  font: 300 40px/1.1 ui-rounded, system-ui, sans-serif;
  font-variant-numeric: tabular-nums;
  word-break: break-all;
  text-align: right;
}
.message {
  min-height: 22px;
  font-size: 15px;
  font-weight: 600;
  color: var(--muted);
  transition: opacity .2s;
}
.message.error { color: var(--danger); }
.message.ok { color: var(--ok); }

.shake { animation: shake .35s; }
@keyframes shake {
  20%, 60% { transform: translateX(-6px); }
  40%, 80% { transform: translateX(6px); }
}

.keypad {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
}
.keypad button {
  height: clamp(42px, 7dvh, 64px);
  border: 0;
  border-radius: 16px;
  background: var(--key);
  color: var(--text);
  font: 500 24px system-ui, sans-serif;
  touch-action: manipulation;
  cursor: pointer;
  transition: transform .06s, filter .06s;
}
.keypad button:active { transform: scale(.95); filter: brightness(1.3); }
.keypad .fn { background: var(--key-fn); color: #c9c3ff; font-size: 20px; }
.keypad .op { background: var(--op); color: #d9d2ff; }
.keypad .wide { grid-column: span 2; }
.keypad .wide3 { grid-column: span 3; }
.keypad .set { background: #2a3b7a; font-size: 18px; font-weight: 600; }
.keypad .spend {
  background: linear-gradient(135deg, var(--mana), var(--mana-2));
  font-weight: 700;
  font-size: 22px;
  letter-spacing: .04em;
  box-shadow: 0 6px 24px rgba(79, 141, 255, .35);
}