/* Tools — currently the research solution calculator. The page is built to
   hold more tools later (each in its own panel), so the section / panel
   styles are reusable. Brand voice: dark surface, gold accents, serif
   for headings + result numbers, sans-mono uppercase for labels.

   Vertical budget: hero + section head + calc panel (inputs + results +
   calculation model) SHOULD fit above the fold on a typical desktop window
   (≥720px). Every margin / padding / font-size below was tuned to that
   target — touch carefully. */

.tools-page { padding-bottom: var(--s-7); }

/* ---------- Hero (compact) ---------- */
.tools-hero {
  padding: var(--s-5) var(--gutter) var(--s-4);
  display: grid;
  grid-template-columns: auto 1fr;
  grid-template-areas: "title meta";
  align-items: end;
  gap: 8px 32px;
  border-bottom: 1px solid var(--rule);
}
.tools-hero__title {
  grid-area: title;
  font-family: var(--font-serif);
  font-size: clamp(28px, 3.2vw, 48px);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--beige-50);
  margin: 0;
}
.tools-hero__title em { font-style: italic; color: var(--gold-100); }
.tools-hero__meta {
  grid-area: meta;
  font-family: var(--font-serif);
  font-style: italic;
  color: var(--gold-200);
  font-size: 14px;
  justify-self: end;
  align-self: end;
  padding-bottom: 4px;
}
@media (max-width: 900px) {
  .tools-hero {
    grid-template-columns: 1fr;
    grid-template-areas: "title" "meta";
  }
  .tools-hero__meta { justify-self: start; padding-bottom: 0; }
}

/* ---------- Section frame ---------- */
.tools-section {
  padding: var(--s-5) var(--gutter);
  max-width: 1080px;
  margin: 0 auto;
}
.tools-section__head {
  display: flex; align-items: baseline; gap: 14px;
  margin-bottom: 14px;
}
.tools-section__num {
  font-family: var(--font-sans);
  font-size: 11px;
  letter-spacing: 0.32em;
  text-transform: uppercase;
  color: var(--gold-200);
}
.tools-section__title {
  font-family: var(--font-serif);
  font-size: clamp(22px, 2.4vw, 35px);
  line-height: 1.05;
  letter-spacing: -0.015em;
  color: var(--beige-50);
  margin: 0;
}
.tools-section__title em { font-style: italic; color: var(--gold-100); }

.calc-intro {
  max-width: 820px;
  margin: 0 0 16px;
  color: var(--beige-200);
  font-size: 15px;
  line-height: 1.65;
}

/* ---------- Calculator panel ----------
   Single card with three regions: inputs (top-left), results (top-right),
   protocol model (full-width bottom). Grid template-areas keeps the structure
   declarative so the mobile collapse below is a one-line override. */
.calc {
  display: grid;
  grid-template-columns: 1fr 1fr;
  grid-template-areas:
    "inputs results"
    "protocol protocol";
  gap: 0;
  border: 1px solid var(--rule);
  background: var(--ink-2);
}
@media (max-width: 800px) {
  .calc {
    grid-template-columns: 1fr;
    grid-template-areas: "inputs" "results" "protocol";
  }
}
.calc__col {
  padding: 18px 22px;
  /* Grid items default to `min-width: auto` (min-content), which lets
     long input fields or unit-toggle button groups
     push the column past the grid track. Explicit 0 lets `1fr` win
     and keeps the calculator inside the viewport at phone widths. */
  min-width: 0;
}
.calc__col--inputs  { grid-area: inputs; }
.calc__col--results { grid-area: results; }
.calc__col + .calc__col { border-left: 1px solid var(--rule); }
@media (max-width: 800px) {
  .calc__col + .calc__col {
    border-left: 0;
    border-top: 1px solid var(--rule);
  }
}
.calc__col-label {
  font-family: var(--font-sans);
  font-size: 10px;
  letter-spacing: 0.36em;
  text-transform: uppercase;
  color: var(--gold-300);
  margin-bottom: 14px;
}

/* ---------- Preset picker (inline next to section title) ---------- */
.calc-presets {
  margin: 0 0 14px;
  display: flex;
  align-items: center;
  gap: 12px;
}
.calc-presets__label {
  font-family: var(--font-sans);
  font-size: 10px;
  letter-spacing: 0.36em;
  text-transform: uppercase;
  color: var(--gold-200);
  white-space: nowrap;
  flex-shrink: 0;
}
.calc-presets__select {
  flex: 1;
  /* Flex items default to min-width: auto = min-content; the longest
     <option> label would otherwise force the select wider than the
     viewport on ≤320px phones. Zero lets flex-shrink: 1 do its job. */
  min-width: 0;
  max-width: 360px;
  padding: 8px 12px;
  background: var(--ink-1);
  border: 1px solid var(--rule);
  color: var(--beige-50);
  font-family: var(--font-sans);
  font-size: 14px;
  cursor: pointer;
  appearance: none;
  -webkit-appearance: none;
  background-image: url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='12' height='8' viewBox='0 0 12 8' fill='none' stroke='%23d4af60' stroke-width='1.4'><path d='M1 1l5 5 5-5'/></svg>");
  background-repeat: no-repeat;
  background-position: right 12px center;
  padding-right: 32px;
  transition: border-color var(--dur-fast) var(--ease);
}
.calc-presets__select:focus {
  outline: none;
  border-color: var(--gold-300);
}
.calc-presets__select option {
  background: var(--ink-1);
  color: var(--beige-50);
}
.calc-presets__hint {
  margin: -8px 0 14px;
  max-width: 760px;
  color: var(--fg-muted);
  font-size: 11px;
  line-height: 1.5;
}

/* ---------- Field group ---------- */
.calc-field {
  margin-bottom: 12px;
}
.calc-field:last-child { margin-bottom: 0; }
.calc-field__label {
  display: block;
  font-family: var(--font-sans);
  font-size: 10px;
  letter-spacing: 0.36em;
  text-transform: uppercase;
  color: var(--beige-300);
  margin-bottom: 4px;
}
.calc-field__row {
  display: flex;
  gap: 0;
  border-bottom: 1px solid var(--gold-400);
  align-items: stretch;
}
.calc-field__input {
  flex: 1;
  padding: 6px 0;
  background: transparent;
  border: 0;
  outline: 0;
  color: var(--beige-50);
  font-family: var(--font-serif);
  font-size: clamp(19px, 2vw, 26px);
  letter-spacing: -0.01em;
  /* Hide native spinner — we want a clean numeric field. */
  -moz-appearance: textfield;
  appearance: textfield;
}
.calc-field__input::-webkit-outer-spin-button,
.calc-field__input::-webkit-inner-spin-button { -webkit-appearance: none; margin: 0; }
.calc-field__row:focus-within { border-bottom-color: var(--gold-200); }
.calc-field__unit-static {
  display: inline-flex;
  align-items: center;
  padding: 0 0 0 10px;
  font-family: var(--font-sans);
  font-size: 12px;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--gold-200);
}
.calc-field__unit-toggle {
  display: inline-flex;
  align-self: center;
  margin-left: 8px;
  border: 1px solid var(--rule);
}
.calc-field__unit-toggle button {
  padding: 12px 12px;
  /* Tap target — calculator unit toggles are used during lab preparation.
     A miss-tap here flips mg/mcg, which is a 1000× scale error.
     Worth the extra space. */
  min-height: 44px;
  min-width: 44px;
  background: transparent;
  border: 0;
  border-right: 1px solid var(--rule);
  color: var(--beige-300);
  font-family: var(--font-sans);
  font-size: 10px;
  letter-spacing: 0.22em;
  text-transform: uppercase;
  cursor: pointer;
  transition: color var(--dur-fast) var(--ease),
              background var(--dur-fast) var(--ease);
}
.calc-field__unit-toggle button:last-child { border-right: 0; }
.calc-field__unit-toggle button:hover { color: var(--gold-100); }
.calc-field__unit-toggle button.is-active {
  background: rgba(212, 175, 96, 0.14);
  color: var(--gold-100);
}
.calc-field__hint {
  margin-top: 4px;
  font-size: 11px;
  color: var(--fg-muted);
}
.calc-field__hint--warn { color: #d4af60; font-style: italic; }
.calc-field__hint-link {
  display: inline-block;
  margin-left: 4px;
  color: var(--gold-200);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--dur-fast) var(--ease),
              border-bottom-color var(--dur-fast) var(--ease);
}
.calc-field__hint-link:hover,
.calc-field__hint-link:focus-visible {
  color: var(--gold-100);
  border-bottom-color: var(--gold-300);
  outline: none;
}
/* Link inside the field label — gold tint, subtle bottom-border on
   hover. Letter-spacing inherits from the label, color stands out so
   the user notices the cross-link without losing the tracked-uppercase
   look of the label. */
.calc-field__label-link {
  color: var(--gold-200);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--dur-fast) var(--ease),
              border-bottom-color var(--dur-fast) var(--ease);
}
.calc-field__label-link:hover,
.calc-field__label-link:focus-visible {
  color: var(--gold-100);
  border-bottom-color: var(--gold-300);
  outline: none;
}

/* ---------- Result rows ---------- */
.calc-result {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: baseline;
  gap: 14px;
  padding: 8px 0;
  border-bottom: 1px solid var(--rule);
}
.calc-result:last-child { border-bottom: 0; }
.calc-result__label {
  font-family: var(--font-sans);
  font-size: 10px;
  letter-spacing: 0.32em;
  text-transform: uppercase;
  color: var(--beige-300);
}
.calc-result__label .sub {
  display: block;
  margin-top: 2px;
  font-size: 10px;
  letter-spacing: 0.04em;
  text-transform: none;
  font-style: italic;
  color: var(--fg-muted);
}
.calc-result__value {
  font-family: var(--font-serif);
  font-size: clamp(22px, 2.2vw, 28px);
  color: var(--beige-50);
  letter-spacing: -0.01em;
  text-align: right;
}
.calc-result__value-sub {
  font-family: var(--font-sans);
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--gold-200);
  margin-left: 6px;
}

/* Formula strip, full-width across the inputs and results columns. */
.calc-protocol {
  grid-area: protocol;
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 12px 22px;
  align-items: baseline;
  border-top: 1px solid var(--rule);
  padding: 14px 22px;
  background: var(--ink-1);
  color: var(--fg-muted);
  font-size: 12px;
  line-height: 1.55;
}
.calc-protocol strong {
  color: var(--gold-200);
  font-family: var(--font-sans);
  font-size: 10px;
  font-weight: 500;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  white-space: nowrap;
}
@media (max-width: 600px) {
  .calc-protocol { grid-template-columns: 1fr; gap: 6px; }
}

/* ---------- Disclaimer strip ---------- */
.calc-disclaimer {
  margin-top: 20px;
  padding: 18px 20px;
  border: 1px solid var(--rule);
  background: rgba(212, 175, 96, 0.04);
  font-size: 15px;
  line-height: 1.65;
  color: var(--beige-200);
}
.calc-disclaimer p {
  margin: 0;
}
.calc-disclaimer p + p {
  margin-top: 10px;
}
.calc-disclaimer strong { color: var(--gold-100); font-weight: 500; }
.calc-disclaimer em { color: var(--beige-100); font-style: italic; }
@media (max-width: 600px) {
  .calc-disclaimer { padding: 14px 14px; font-size: 15px; }
}

/* ---------- PDP calculator link (used on product pages) ---------- */
.pdp__calc-link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin-top: 12px;
  font-family: var(--font-sans);
  font-size: 11px;
  letter-spacing: 0.32em;
  text-transform: uppercase;
  color: var(--gold-200);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  padding-bottom: 2px;
  transition: color var(--dur-fast) var(--ease),
              border-bottom-color var(--dur-fast) var(--ease);
}
.pdp__calc-link:hover {
  color: var(--gold-100);
  border-bottom-color: var(--gold-300);
}
.pdp__calc-link svg { color: var(--gold-300); }