.display {
  background: var(--display-grad);
  border-radius: 12px;
  padding: 22px 18px 18px;
  margin-bottom: 16px;
  box-shadow: inset 0 2px 10px rgba(31, 20, 80, 0.18);
  min-height: 96px;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  gap: 6px;
  overflow: hidden;
}

.expression {
  font-family: var(--mono);
  font-size: 14px;
  color: rgba(255, 255, 255, 0.75);
  min-height: 18px;
  white-space: nowrap;
  overflow-x: auto;
  text-align: right;
}

.result {
  font-family: var(--mono);
  font-size: 38px;
  font-weight: 600;
  color: #ffffff;
  text-shadow: 0 1px 12px rgba(31, 20, 80, 0.25);
  text-align: right;
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
  overflow-x: auto;
}

.result.error {
  color: #ffd0dc;
  text-shadow: none;
  font-size: 22px;
}

.keys {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 8px;
}

.key {
  font-family: var(--mono);
  font-size: 18px;
  padding: 16px 0;
  border-radius: 10px;
  border: 1px solid var(--panel-border);
  background: var(--key-bg);
  color: var(--text-primary);
  cursor: pointer;
  transition: transform 0.05s ease, background 0.15s ease;
}

.key:hover { background: var(--key-bg-hover); }
.key:active { transform: translateY(1px) scale(0.98); }

.key-fn {
  color: var(--accent-rose);
  background: var(--accent-rose-dim);
  border-color: transparent;
  font-size: 15px;
}
.key-fn:hover { background: rgba(225, 29, 116, 0.18); }

.key-percent {
  color: var(--accent-amber);
  background: var(--accent-amber-dim);
  border-color: transparent;
}
.key-percent:hover { background: rgba(217, 119, 6, 0.2); }

.key-op {
  color: var(--accent-teal);
  background: var(--accent-teal-dim);
  border-color: transparent;
}
.key-op:hover { background: rgba(13, 148, 136, 0.2); }

.key-equals {
  background: var(--accent-primary);
  border-color: var(--accent-primary);
  color: var(--text-on-accent);
  font-weight: 700;
}
.key-equals:hover { background: #6a48f2; }

.key:focus-visible { outline: 2px solid var(--accent-primary); outline-offset: 2px; }

@media (max-width: 400px) {
  .result { font-size: 32px; }
  .key { font-size: 16px; padding: 14px 0; }
}