/* ============================================================================
   /tools/grade-converter/ — the grade converter

   TOKENS: this is a PUBLIC page, so it uses the public tokens.css namespace
   (--color-*). It must NOT use the portal's --p-* namespace: --p-card-solid is
   defined only inside portal.css/chat.css/admin-deck.css, so
   `var(--p-card-solid, #fff)` silently resolves to WHITE on a dark page. That bug
   shipped for one round here (white card, white-on-white outline button).
   Every token below was checked to exist in tokens.css.

   The card is OPAQUE (--color-bg-card, not --color-bg-glass): a translucent
   surface behind scrolling content leaks a visible band, which has bitten twice.
   ============================================================================ */

.tool-wrap { max-width: 780px; margin: 0 auto; }

.tool-card {
  background: var(--color-bg-card);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-2xl);
  padding: clamp(18px, 3vw, 32px);
  box-shadow: 0 18px 50px rgba(2, 6, 23, .10);
}

.tool-grid { display: grid; grid-template-columns: 1fr 1fr; gap: var(--space-4); }
@media (max-width: 640px) { .tool-grid { grid-template-columns: 1fr; } }

.tool-field { display: flex; flex-direction: column; gap: 8px; min-width: 0; }
.tool-field[hidden] { display: none; }
.tool-field label {
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--color-ink-muted);
  letter-spacing: .01em;
}

/* 16px font on purpose: anything smaller makes iOS Safari zoom the page on focus. */
.tool-field select,
.tool-field input {
  width: 100%;
  min-height: 48px;
  padding: 12px 14px;
  font-size: 16px;
  font-family: inherit;
  color: var(--color-ink);
  background: var(--color-bg-alt);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  transition: border-color .15s ease, box-shadow .15s ease;
}
.tool-field select:focus-visible,
.tool-field input:focus-visible {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px color-mix(in srgb, var(--color-primary) 28%, transparent);
}
.tool-field input::-webkit-outer-spin-button,
.tool-field input::-webkit-inner-spin-button { -webkit-appearance: none; margin: 0; }
.tool-field input[type=number] { -moz-appearance: textfield; appearance: textfield; }

.tool-err {
  margin: 14px 0 0;
  padding: 11px 14px;
  border-radius: var(--radius-lg);
  font-size: var(--text-sm);
  background: color-mix(in srgb, #f59e0b 16%, transparent);
  border: 1px solid color-mix(in srgb, #f59e0b 45%, transparent);
  color: var(--color-ink);
}
.tool-err[hidden] { display: none; }

/* ---------------------------------------------------------------- the result */
.tool-result {
  margin-top: var(--space-4);
  padding-top: var(--space-4);
  border-top: 1px dashed var(--color-border);
}
.tool-result[hidden] { display: none; }
.tool-result-label { font-size: var(--text-sm); color: var(--color-ink-muted); margin: 0 0 6px; }

.tool-score {
  display: flex;
  align-items: baseline;
  gap: 6px;
  margin: 0 0 4px;
  font-variant-numeric: tabular-nums;
}
.tool-score b {
  font-family: var(--font-display);
  font-size: clamp(2.75rem, 9vw, 4rem);
  font-weight: 800;
  line-height: 1;
  color: var(--color-primary);
}
.tool-score span { font-size: var(--text-lg); color: var(--color-ink-muted); }

.tool-equiv {
  margin: 0 0 var(--space-4);
  font-size: var(--text-sm);
  color: var(--color-ink-muted);
  font-variant-numeric: tabular-nums;
}

.tool-csca {
  margin: 0 0 var(--space-4);
  padding: 12px 14px;
  font-size: var(--text-sm);
  line-height: 1.6;
  background: color-mix(in srgb, var(--color-primary) 8%, transparent);
  border-left: 3px solid var(--color-primary);
  border-radius: 10px;
  color: var(--color-ink);
}

.tool-actions { display: flex; flex-wrap: wrap; gap: 10px; }
.tool-actions .btn { min-height: 44px; }

.tool-note {
  margin-top: var(--space-4);
  font-size: var(--text-xs);
  line-height: 1.6;
  color: var(--color-ink-muted);
}
.tool-privacy {
  margin: 12px 0 0;
  font-size: var(--text-xs);
  color: var(--color-ink-muted);
}