/* Scientific calculator keypad — homepage only */
.calc {
  max-width: 420px; margin: 0 auto; background: var(--surface);
  border: 1px solid var(--border); border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg); padding: 16px; overflow: hidden;
}
.calc-display {
  background: var(--surface-2); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 14px 16px; text-align: right; margin-bottom: 12px; min-height: 92px;
  display: flex; flex-direction: column; justify-content: flex-end;
}
.calc-expr { color: var(--text-3); font-family: var(--mono); font-size: .95rem; min-height: 22px;
  overflow-x: auto; white-space: nowrap; }
.calc-out { color: var(--text); font-family: var(--mono); font-weight: 700;
  font-size: clamp(1.7rem, 1.2rem + 3vw, 2.3rem); overflow-x: auto; white-space: nowrap; }
.calc-meta { display: flex; justify-content: space-between; align-items: center; margin-bottom: 10px;
  font-size: .8rem; color: var(--text-3); }
.calc-meta button { background: none; border: 1px solid var(--border); color: var(--text-3);
  border-radius: 8px; padding: 4px 10px; cursor: pointer; font: inherit; font-size: .8rem; }
.calc-meta button.on { background: var(--brand-600); color: #fff; border-color: var(--brand-600); }

.keys { display: grid; grid-template-columns: repeat(5, 1fr); gap: 8px; }
.key {
  border: 1px solid var(--border); background: var(--surface-2); color: var(--text);
  font: inherit; font-size: 1.05rem; font-weight: 600; padding: 14px 0; border-radius: 12px;
  cursor: pointer; transition: transform .08s ease, background .12s ease; user-select: none;
}
.key:hover { background: var(--border); }
.key:active { transform: scale(.95); }
.key.fn { background: transparent; color: var(--accent-600); font-size: .9rem; }
:root[data-theme="dark"] .key.fn { color: #a5b4fc; }
@media (prefers-color-scheme: dark){ :root:not([data-theme="light"]) .key.fn { color:#a5b4fc; } }
.key.op { color: var(--brand-700); }
:root[data-theme="dark"] .key.op { color: var(--brand-400); }
@media (prefers-color-scheme: dark){ :root:not([data-theme="light"]) .key.op { color: var(--brand-400);} }
.key.eq { background: var(--brand-600); color: #fff; border-color: var(--brand-600); grid-column: span 2; }
.key.eq:hover { background: var(--brand-700); }
.key.clear { color: var(--danger); }
.key.wide { grid-column: span 2; }
.key.full { grid-column: 1 / -1; }
@media (max-width: 420px){ .keys { gap: 6px; } .key { padding: 13px 0; font-size: 1rem; } }