/*
 * theme.css — Calculator. A desk instrument, like a Braun ET66: warm grey
 * body, quiet keys, one orange equals key. Opens light; dark is the same
 * instrument in charcoal with a brighter orange.
 */

:root {
  --canvas: #ece8e1;
  --surface: #f7f5f1;
  --surface-2: #e2ddd4;
  --border: #d3cdc2;
  --border-strong: #a59e92;
  --ink: #1c1a17;
  --muted: #5e5951;
  --accent: #c2410c;
  --accent-hover: #a8380a;
  --accent-ink: #ffffff;
  --accent-text: #a3360a;
  --accent-strong: #7a2805;
  --accent-soft: #f6dccd;
  --accent-border: #e8b393;
  --success: #15803d;
  --success-ink: #ffffff;
  --success-soft: #dfebe3;
  --success-strong: #137638;
  --warning: #b45309;
  --warning-ink: #ffffff;
  --warning-soft: #f2e6dd;
  --warning-strong: #a64c08;
  --danger: #b91c1c;
  --danger-ink: #ffffff;
  --danger-soft: #f2dfdf;
  --danger-strong: #b91c1c;
  --chart-1: #c2410c;
  --chart-2: #7c285c;
  --chart-3: #425605;
  --chart-4: #0b5668;
  --chart-5: #5152a5;
  --chart-6: #1c1a17;

  --font-display: "Space Grotesk", ui-sans-serif, system-ui, sans-serif;
  --font-body: "Space Grotesk", ui-sans-serif, system-ui, sans-serif;
  --font-sans: "Space Grotesk", ui-sans-serif, system-ui, sans-serif;
  --font-mono: "JetBrains Mono", ui-monospace, SFMono-Regular, Menlo, Consolas, monospace;
  --display-weight: 600;
  --display-tracking: -0.02em;
  --eyebrow-tracking: 0.08em;

  --radius-btn: 0.75rem;
  --radius-card: 1.5rem;
  --radius-input: 0.75rem;
}

html[data-theme="dark"] {
  --canvas: #121212;
  --surface: #1c1b1a;
  --surface-2: #2a2826;
  --border: #34312e;
  --border-strong: #57534e;
  --ink: #f3f0ea;
  --muted: #a8a29a;
  --accent: #f07a2a;
  --accent-hover: #f59144;
  --accent-ink: #1a0b03;
  --accent-text: #f59a5a;
  --accent-strong: #f8b88a;
  --accent-soft: #3b2216;
  --accent-border: #6b3a1f;
  --success: #15803d;
  --success-ink: #ffffff;
  --success-soft: #172f22;
  --success-strong: #58a474;
  --warning: #b45309;
  --warning-ink: #ffffff;
  --warning-soft: #3a2517;
  --warning-strong: #ca854f;
  --danger: #b91c1c;
  --danger-ink: #ffffff;
  --danger-soft: #3b191b;
  --danger-strong: #d57575;
  --chart-1: #f07a2a;
  --chart-2: #cb70a4;
  --chart-3: #98911a;
  --chart-4: #159670;
  --chart-5: #1c9ec8;
  --chart-6: #f3f0ea;
}

/*
 * app.css — the calculator instrument and its tape. Tokens only.
 */

.calc {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 2rem;
  padding: 1.25rem;
  box-shadow:
    0 1px 0 color-mix(in srgb, var(--ink) 5%, transparent),
    0 28px 56px -28px color-mix(in srgb, var(--ink) 40%, transparent);
}

.calc-screen {
  background: var(--surface-2);
  border-radius: 1.25rem;
  padding: 1rem 1rem 0.5rem 1.25rem;
  min-height: 9.5rem;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  box-shadow: inset 0 2px 6px color-mix(in srgb, var(--ink) 12%, transparent);
}

.calc-line {
  font-family: var(--font-mono);
  color: var(--muted);
  font-size: 0.95rem;
  min-height: 1.5rem;
  text-align: right;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.calc-line.is-error { color: var(--danger-strong); font-family: var(--font-body); }

.calc-main {
  display: block;
  font-family: var(--font-mono);
  font-weight: 500;
  font-size: 3rem;
  line-height: 1.15;
  letter-spacing: -0.03em;
  text-align: right;
  color: var(--ink);
  white-space: nowrap;
  overflow-x: auto;
  scrollbar-width: none;
}
.calc-main::-webkit-scrollbar { display: none; }
.calc-main[data-size="m"] { font-size: 2.25rem; }
.calc-main[data-size="s"] { font-size: 1.6rem; }

.calc-key {
  height: 4rem;
  border-radius: 1rem;
  font-family: var(--font-display);
  font-size: 1.375rem;
  font-weight: 500;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--surface-2);
  color: var(--ink);
  border: 1px solid var(--border);
  box-shadow: 0 3px 0 var(--border);
  cursor: pointer;
  user-select: none;
  -webkit-tap-highlight-color: transparent;
  transition: transform 0.07s ease, box-shadow 0.07s ease, background-color 0.15s ease;
}
.calc-key:hover { background: color-mix(in srgb, var(--surface-2) 88%, var(--ink)); }
.calc-key:active,
.calc-key.is-pressed { transform: translateY(3px); box-shadow: 0 0 0 var(--border); }
.calc-key:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.calc-key .icon { width: 1.4rem; height: 1.4rem; }

.calc-key-fn { background: var(--surface); color: var(--muted); font-size: 1.125rem; }
.calc-key-fn:hover { background: var(--surface-2); color: var(--ink); }

.calc-key-op {
  background: var(--accent-soft);
  color: var(--accent-strong);
  border-color: var(--accent-border);
  box-shadow: 0 3px 0 var(--accent-border);
}
.calc-key-op:hover { background: color-mix(in srgb, var(--accent-soft) 85%, var(--accent)); }
.calc-key-op:active,
.calc-key-op.is-pressed { box-shadow: 0 0 0 var(--accent-border); }

.calc-key-eq {
  background: var(--accent);
  color: var(--accent-ink);
  border-color: var(--accent);
  box-shadow: 0 3px 0 var(--accent-hover);
}
.calc-key-eq:hover { background: var(--accent-hover); }
.calc-key-eq:active,
.calc-key-eq.is-pressed { box-shadow: 0 0 0 var(--accent-hover); }

html.reduced-motion .calc-key { transition: none; }
html.reduced-motion .calc-key.is-pressed,
html.reduced-motion .calc-key:active { transform: none; }

@media (max-width: 400px) {
  .calc { padding: 1rem; border-radius: 1.5rem; }
  .calc-key { height: 3.5rem; }
  .calc-main { font-size: 2.5rem; }
}

/* The tape: a running list of answers. */
.tape { display: flex; flex-direction: column; }
.tape-item {
  display: block;
  width: 100%;
  text-align: right;
  padding: 0.75rem 0.5rem;
  border-top: 1px dashed var(--border);
  border-radius: 0.5rem;
  cursor: pointer;
  background: transparent;
  color: var(--ink);
}
.tape li:first-child .tape-item { border-top-color: transparent; }
.tape-item:hover { background: var(--surface-2); }
.tape-item:focus-visible { outline: 2px solid var(--accent); outline-offset: 2px; }
.tape-expr {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--muted);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.tape-result {
  display: block;
  font-family: var(--font-mono);
  font-size: 1.25rem;
  font-weight: 500;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.tape li.is-new .tape-item { animation: tape-in 0.25s ease-out; }
@keyframes tape-in {
  from { transform: translateY(-0.5rem); }
  to { transform: translateY(0); }
}
html.reduced-motion .tape li.is-new .tape-item { animation: none; }