/* Basic calculator - screen + 4-column keypad. */
.bc-screen {
    background: var(--e-surface); border: 1px solid var(--e-line); border-radius: 10px;
    padding: 10px 12px; margin-bottom: var(--e-gap); text-align: right; min-width: 0;
}
.bc-expr { font-size: .85em; color: var(--e-ink-3); min-height: 1.3em; overflow-wrap: anywhere; font-variant-numeric: tabular-nums; }
.bc-value { display: block; font-size: 2em; font-weight: 700; line-height: 1.2; overflow-wrap: anywhere; font-variant-numeric: tabular-nums; }
.bc-pad { display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 8px; }
.bc-key {
    font: inherit; font-size: 1.15em; font-weight: 600; min-height: 48px; cursor: pointer;
    border: 1px solid var(--e-line-strong); border-radius: 10px; background: var(--e-bg); color: var(--e-ink);
}
.bc-key:hover { background: var(--e-surface); }
.bc-key.bc-op, .bc-key.bc-fn { background: var(--e-surface); color: var(--e-ink-2); }
.bc-key.bc-eq { background: var(--e-accent); color: var(--e-accent-ink); border-color: var(--e-accent); }
.bc-key:focus-visible { outline: 2px solid var(--e-focus); outline-offset: 2px; }
.bc-key:active { transform: translateY(1px); }
html[data-compact="1"] .bc-key { min-height: 40px; font-size: 1.05em; }
html[data-compact="1"] .bc-value { font-size: 1.6em; }