/* Calculator styles — the interactive polynomial solver. Uses the same
   brand tokens as style.css (--bg, --surface, --ink, --accent, --secondary). */

.calc {
  margin: 1.5rem 0 2.5rem;
  padding: 1.5rem;
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 14px;
  box-shadow: 0 1px 2px var(--shadow);
  text-align: left;
}

.calc-modes {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 1.1rem;
}
.calc-mode-btn {
  flex: 1;
  padding: 0.55rem 0.75rem;
  border: 1px solid var(--line);
  background: transparent;
  color: var(--secondary);
  border-radius: 8px;
  font: inherit;
  font-weight: 600;
  cursor: pointer;
}
.calc-mode-btn.is-active {
  background: var(--ink);
  color: var(--bg);
  border-color: var(--ink);
}

.calc-panel { margin-bottom: 1rem; }
.calc-panel label {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--secondary);
  margin-bottom: 0.5rem;
}

#degree-select {
  font: inherit;
  padding: 0.4rem 0.6rem;
  border-radius: 6px;
  border: 1px solid var(--line);
  background: var(--bg);
  color: var(--ink);
  margin-bottom: 0.75rem;
}

.calc-coeff-inputs {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(96px, 1fr));
  gap: 0.5rem;
}
.calc-coeff-row { display: flex; flex-direction: column; gap: 0.25rem; min-width: 0; }
.calc-coeff-label { font: 0.8rem/1 var(--font-mono); color: var(--secondary); }

.calc-coeff-field,
#freeform-input {
  width: 100%;
  min-width: 0;
  box-sizing: border-box;
  font: 1rem var(--font-mono);
  padding: 0.5rem 0.6rem;
  border-radius: 6px;
  border: 1px solid var(--line);
  background: var(--bg);
  color: var(--ink);
}

.calc-coeff-field:focus,
#freeform-input:focus,
.calc-mode-btn:focus-visible,
.calc-solve-btn:focus-visible,
.calc-link-btn:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

.calc-controls {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 1rem;
  margin-top: 1rem;
}

.calc-precision {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  border: none;
  padding: 0;
  margin: 0;
}
.calc-precision legend {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--secondary);
  padding: 0;
}
.calc-precision label {
  display: inline-flex;
  align-items: center;
  gap: 0.25rem;
  font-size: 0.9rem;
  color: var(--ink);
}
.calc-precision input[type="radio"] { accent-color: var(--accent); }

.calc-solve-btn {
  margin: 0 0 0 auto;
  font-size: 1rem;
}

.calc-error {
  margin-top: 1rem;
  padding: 0.75rem 1rem;
  border-radius: 8px;
  background: #fde2e1;
  color: #86181d;
}
@media (prefers-color-scheme: dark) {
  .calc-error { background: #3a1414; color: #ff8a80; }
}

.calc-results {
  margin-top: 1.25rem;
  padding-top: 1.25rem;
  border-top: 1px solid var(--line);
}
.calc-results h3 {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--secondary);
  margin: 0 0 0.75rem;
}

#calc-roots-list {
  list-style: none;
  margin: 0 0 1rem;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}
.calc-root {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 0.75rem;
  padding: 0.55rem 0.8rem;
  border-radius: 8px;
  background: var(--bg);
}
.calc-root-value { font: 1rem/1.3 var(--font-mono); color: var(--ink); }
.calc-root-tag {
  font-family: var(--font-mono);
  font-size: 0.72rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--accent);
  white-space: nowrap;
}

.calc-link-btn {
  display: inline-block;
  margin: 0 0 1rem;
  padding: 0.5rem 0.9rem;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: transparent;
  color: var(--ink);
  font: inherit;
  font-size: 0.9rem;
  cursor: pointer;
}

.calc-cta {
  display: block;
  margin: 0 0 1rem;
  text-align: center;
}

.calc-graph-wrap { margin-top: 1rem; }
.calc-graph {
  display: block;
  width: 100%;
  height: 280px;
  border-radius: 10px;
  background: var(--bg);
}

/* ---------------------------------------------------------------- */
/* Desktop: input panel and results/graph side by side, Desmos-style */
/* ---------------------------------------------------------------- */
@media (min-width: 860px) {
  .calc {
    display: grid;
    grid-template-columns: minmax(260px, 360px) 1fr;
    gap: 2rem;
    padding: 1.75rem;
    align-items: start;
  }
  .calc-input-col { grid-column: 1; }
  .calc-output-col {
    grid-column: 2;
    border-left: 1px solid var(--line);
    padding-left: 2rem;
    min-height: 100%;
  }
  .calc-results { margin-top: 0; padding-top: 0; border-top: none; }
  .calc-output-col .calc-error { margin-top: 0; }
  .calc-output-placeholder {
    color: var(--secondary);
    font-family: var(--font-mono);
    font-size: 0.9rem;
    padding: 2rem 0;
  }
}

@media (prefers-reduced-motion: no-preference) {
  .calc-mode-btn, .calc-link-btn, .btn { transition: background-color 120ms ease, border-color 120ms ease; }
}

@media (max-width: 400px) {
  .calc { padding: 1rem 0.85rem; }
  .calc-coeff-inputs { grid-template-columns: repeat(auto-fill, minmax(80px, 1fr)); }
  .calc-root { flex-direction: column; align-items: flex-start; gap: 0.15rem; }
}