:root {
  --content-max: 980px;
  --measure: 70ch;
  --warning-text: #8a3b00;
  --warning-surface: rgba(255, 149, 0, 0.12);
  --warning-line: rgba(255, 149, 0, 0.46);
  --success-surface: rgba(52, 199, 89, 0.10);
}

:root[data-theme="dark"] {
  --warning-text: #ffb340;
  --warning-surface: rgba(255, 159, 10, 0.16);
  --warning-line: rgba(255, 159, 10, 0.52);
  --success-surface: rgba(48, 209, 88, 0.14);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme]) {
    --warning-text: #ffb340;
    --warning-surface: rgba(255, 159, 10, 0.16);
    --warning-line: rgba(255, 159, 10, 0.52);
    --success-surface: rgba(48, 209, 88, 0.14);
  }
}

.visually-hidden {
  position: absolute !important;
  width: 1px !important;
  height: 1px !important;
  overflow: hidden !important;
  clip: rect(0 0 0 0) !important;
  clip-path: inset(50%) !important;
  white-space: nowrap !important;
}

.content-article--wide {
  max-width: var(--content-max);
}

.content-hero--tool h1,
.content-hero--article h1 {
  max-width: 15ch;
}

.content-hero--tool p,
.content-hero--article p {
  max-width: var(--measure);
}

.content-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 8px 18px;
  margin: 20px 0 0;
  color: var(--muted);
  font-size: 0.9rem;
}

.content-meta span {
  display: inline-flex;
  align-items: center;
  gap: 7px;
}

.content-meta span::before {
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background: var(--accent-strong);
  content: "";
}

.inline-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
}

.inline-actions .button {
  margin-top: 0;
}

.tool-shell {
  display: grid;
  grid-template-columns: minmax(0, 0.88fr) minmax(320px, 1.12fr);
  gap: 18px;
  align-items: start;
}

.tool-shell > *,
.formula-card,
.calculator-stage,
.field {
  min-width: 0;
}

.calculator-panel,
.result-panel,
.tool-card,
.article-callout,
.formula-card,
.reference-panel {
  border: 1px solid var(--line);
  border-radius: var(--tile-radius);
  background: var(--surface);
}

.calculator-panel,
.result-panel {
  max-width: 100%;
  padding: clamp(20px, 4vw, 32px);
}

.calculator-panel h2,
.result-panel h2 {
  font-size: clamp(1.45rem, 3vw, 2rem);
}

.calculator-intro {
  margin: 12px 0 0;
  color: var(--muted);
}

.calculator-form {
  display: grid;
  gap: 22px;
  margin-top: 26px;
}

.form-row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
}

.field {
  display: grid;
  gap: 8px;
}

.field label {
  font-size: 0.93rem;
  font-weight: 800;
}

.field-hint {
  margin: -2px 0 0;
  color: var(--muted);
  font-size: 0.86rem;
}

.field input,
.field select {
  width: 100%;
  min-height: 48px;
  border: 1px solid var(--line);
  border-radius: var(--control-radius);
  padding: 10px 12px;
  background: var(--surface-soft);
  color: var(--text);
  font: inherit;
}

.field input:hover,
.field select:hover {
  border-color: var(--muted);
}

.field input:focus-visible,
.field select:focus-visible,
.citation-ref:focus-visible,
.table-link:focus-visible {
  outline: 3px solid var(--accent-soft);
  outline-offset: 2px;
  border-color: var(--accent-strong);
}

.field input[aria-invalid="true"] {
  border-color: var(--warning-text);
}

.field-error {
  min-height: 1.35em;
  margin: 0;
  color: var(--warning-text);
  font-size: 0.86rem;
  font-weight: 700;
}

.calculator-form .button {
  width: 100%;
  cursor: pointer;
  font: inherit;
}

.result-panel {
  min-height: 100%;
}

.result-kicker {
  margin: 0;
  color: var(--accent-strong);
  font-size: 0.78rem;
  font-weight: 900;
  text-transform: uppercase;
}

.result-primary {
  display: grid;
  gap: 7px;
  margin-top: 12px;
  border-bottom: 1px solid var(--line);
  padding-bottom: 24px;
}

.result-formula {
  color: var(--muted);
  font-size: 0.94rem;
  font-weight: 800;
}

.result-value {
  font-size: clamp(2.6rem, 7vw, 5rem);
  font-weight: 900;
  line-height: 1;
  letter-spacing: -0.04em;
}

.result-disclaimer {
  max-width: 60ch;
  margin: 12px 0 0;
  color: var(--muted);
  font-size: 0.92rem;
}

.result-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  margin: 18px 0 0;
}

.result-stat {
  border: 1px solid var(--line);
  border-radius: var(--control-radius);
  padding: 14px;
  background: var(--surface-soft);
}

.result-stat dt {
  color: var(--muted);
  font-size: 0.8rem;
  font-weight: 800;
  text-transform: uppercase;
}

.result-stat dd {
  margin: 5px 0 0;
  font-weight: 850;
}

.reliability-warning:not([hidden]) {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 12px;
  margin-top: 18px;
  border: 1px solid var(--warning-line);
  border-radius: var(--control-radius);
  padding: 14px;
  background: var(--warning-surface);
  color: var(--warning-text);
}

.reliability-warning[hidden] {
  display: none;
}

.reliability-warning::before {
  display: grid;
  width: 26px;
  height: 26px;
  place-items: center;
  border: 2px solid currentColor;
  border-radius: 50%;
  content: "!";
  font-weight: 900;
}

.reliability-warning strong {
  display: block;
  margin-bottom: 3px;
}

.reliability-warning p {
  margin: 0;
  color: inherit;
  font-size: 0.9rem;
}

.table-heading {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 16px;
  margin-top: 26px;
}

.table-heading h3 {
  font-size: 1.1rem;
}

.table-heading p {
  margin: 0;
  color: var(--muted);
  font-size: 0.86rem;
}

.table-scroll {
  max-width: 100%;
  margin-top: 10px;
  border: 1px solid var(--line);
  border-radius: var(--control-radius);
  overflow-x: auto;
}

.results-table {
  width: 100%;
  border-collapse: collapse;
  font-variant-numeric: tabular-nums;
  table-layout: fixed;
}

.results-table th,
.results-table td {
  padding: 12px 14px;
  border-bottom: 1px solid var(--line);
  text-align: left;
}

.results-table th:last-child,
.results-table td:last-child {
  width: 38%;
  text-align: right;
  white-space: nowrap;
}

.results-table th:first-child,
.results-table td:first-child {
  width: 62%;
}

.results-table thead th {
  background: var(--surface-soft);
  color: var(--muted);
  font-size: 0.78rem;
  letter-spacing: 0.03em;
  text-transform: uppercase;
}

.results-table tbody tr:last-child th,
.results-table tbody tr:last-child td {
  border-bottom: 0;
}

.results-table tbody tr[data-primary] {
  background: var(--accent-soft);
  color: var(--accent-strong);
}

.results-table tbody tr[data-primary] th,
.results-table tbody tr[data-primary] td {
  font-weight: 850;
}

.selected-marker {
  display: block;
  min-height: 1.2em;
  color: var(--accent-strong);
  font-size: 0.72rem;
  font-weight: 900;
  text-transform: uppercase;
}

.method-grid,
.formula-grid,
.tool-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
  margin-top: 22px;
}

.method-card,
.formula-card,
.tool-card {
  padding: 20px;
}

.method-card {
  border-top: 1px solid var(--line);
  padding: 18px 0 0;
}

.method-card h3,
.formula-card h3,
.tool-card h2,
.tool-card h3 {
  font-size: 1.12rem;
}

.formula-card h3 {
  margin-top: 0;
}

.method-card p,
.formula-card p,
.tool-card p {
  margin: 10px 0 0;
  color: var(--muted);
}

.formula-card {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.equation {
  display: block;
  max-width: 100%;
  overflow-x: auto;
  border-radius: var(--control-radius);
  padding: 13px 14px;
  background: var(--surface-soft);
  color: var(--text);
  font-family: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
  font-size: 0.91rem;
  font-variant-numeric: tabular-nums;
  white-space: nowrap;
}

.citation-entry {
  margin-top: auto;
  border-top: 1px solid var(--line);
  padding-top: 13px;
  color: var(--muted);
  font-size: 0.88rem;
}

.citation-entry cite {
  color: var(--text);
  font-style: normal;
}

.table-link {
  color: var(--accent-strong);
  font-weight: 800;
}

.citation-ref {
  display: inline-flex;
  min-width: 1.7em;
  min-height: 1.7em;
  align-items: center;
  justify-content: center;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--accent-soft);
  color: var(--accent-strong);
  font-size: 0.7em;
  font-weight: 900;
  line-height: 1;
  text-decoration: none;
  vertical-align: super;
}

.reference-panel {
  padding: var(--content-card-padding);
}

.reference-panel h2 {
  font-size: clamp(1.4rem, 3vw, 2rem);
}

.citation-list {
  display: grid;
  gap: 16px;
  margin: 20px 0 0;
  padding-left: 1.4rem;
}

.citation-list li {
  padding-left: 5px;
  color: var(--muted);
}

.citation-list li::marker {
  color: var(--accent-strong);
  font-weight: 900;
}

.citation-list cite {
  color: var(--text);
  font-style: normal;
}

.citation-list a {
  color: var(--accent-strong);
  font-weight: 750;
}

.article-copy {
  max-width: var(--measure);
}

.article-copy > * + * {
  margin-top: 16px;
}

.article-copy h2 {
  margin-top: 0;
  font-size: clamp(1.55rem, 3vw, 2.25rem);
}

.article-copy h3 {
  margin-top: 30px;
  font-size: 1.18rem;
}

.article-copy p,
.article-copy li {
  color: var(--muted);
}

.article-copy strong {
  color: var(--text);
}

.article-callout {
  margin-top: 22px;
  padding: 20px;
  background: var(--surface-soft);
}

.article-callout h3 {
  margin: 0;
}

.article-callout p {
  margin: 10px 0 0;
}

.article-callout--accent {
  border-color: rgba(0, 122, 255, 0.35);
  background: var(--accent-soft);
}

.article-callout--accent p {
  color: var(--text);
}

.practical-list {
  display: grid;
  gap: 12px;
  margin: 20px 0 0;
  padding: 0;
  list-style: none;
}

.practical-list li {
  position: relative;
  border-top: 1px solid var(--line);
  padding: 14px 0 0 30px;
}

.practical-list li::before {
  position: absolute;
  top: 14px;
  left: 0;
  display: grid;
  width: 20px;
  height: 20px;
  place-items: center;
  border-radius: 50%;
  background: var(--accent-soft);
  color: var(--accent-strong);
  content: "✓";
  font-size: 0.72rem;
  font-weight: 900;
}

.tool-card {
  display: flex;
  min-height: 230px;
  flex-direction: column;
}

.tool-card__label {
  margin: 0 0 14px;
  color: var(--accent-strong);
  font-size: 0.76rem;
  font-weight: 900;
  text-transform: uppercase;
}

.tool-card .button,
.tool-card .text-link {
  align-self: flex-start;
  margin-top: auto;
}

.breadcrumbs {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin: 0 0 18px;
  color: var(--muted);
  font-size: 0.88rem;
}

.breadcrumbs a {
  color: var(--accent-strong);
  font-weight: 800;
}

.breadcrumbs span[aria-hidden="true"] {
  color: var(--muted);
}

.content-section--plain {
  border: 0;
  padding: 0;
  background: transparent;
}

.content-section--plain > h2 {
  font-size: clamp(1.7rem, 3.6vw, 2.6rem);
}

.page-note {
  display: flex;
  gap: 12px;
  border: 1px solid var(--line);
  border-radius: var(--control-radius);
  padding: 14px 16px;
  background: var(--surface-soft);
  color: var(--muted);
  font-size: 0.9rem;
}

.page-note strong {
  color: var(--text);
}

.body-fat-tool {
  grid-template-columns: minmax(0, 1.18fr) minmax(300px, 0.82fr);
}

.choice-fieldset {
  min-width: 0;
  margin: 0;
  border: 0;
  padding: 0;
}

.choice-fieldset legend {
  margin-bottom: 9px;
  padding: 0;
  font-size: 0.93rem;
  font-weight: 800;
}

.choice-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px;
}

.choice-grid--methods {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.choice-control {
  display: flex;
  min-width: 0;
  align-items: flex-start;
  gap: 9px;
  border: 1px solid var(--line);
  border-radius: var(--control-radius);
  padding: 11px;
  background: var(--surface-soft);
  cursor: pointer;
}

.choice-control:hover {
  border-color: var(--muted);
}

.choice-control:has(input:checked) {
  border-color: var(--accent-strong);
  background: var(--accent-soft);
}

.choice-control:has(input:focus-visible) {
  outline: 3px solid var(--accent-soft);
  outline-offset: 2px;
}

.choice-control input {
  width: 18px;
  height: 18px;
  flex: 0 0 auto;
  margin: 2px 0 0;
  accent-color: var(--accent-strong);
}

.choice-control span {
  display: grid;
  min-width: 0;
  gap: 2px;
}

.choice-control strong {
  font-size: 0.88rem;
}

.choice-control small {
  color: var(--muted);
  font-size: 0.76rem;
  line-height: 1.3;
}

.measurement-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.measurement-grid .field {
  align-content: start;
}

.measurement-grid .field[hidden],
.result-stats[hidden],
.result-stat[hidden] {
  display: none;
}

.form-error {
  min-height: 0;
}

.form-error:empty {
  display: none;
}

.result-stats--body-fat {
  grid-template-columns: minmax(0, 1fr);
}

.result-context {
  margin-top: 22px;
  border-top: 1px solid var(--line);
  padding-top: 20px;
}

.result-context h3 {
  font-size: 1rem;
}

.result-context p {
  margin: 8px 0 0;
  color: var(--muted);
  font-size: 0.9rem;
}

.calculation-summary .equation {
  margin-top: 10px;
}

.calculation-summary strong {
  color: var(--text);
}

.source-type {
  display: inline-flex;
  align-self: flex-start;
  margin: 0;
  border-radius: 999px;
  padding: 5px 8px;
  background: var(--accent-soft);
  color: var(--accent-strong) !important;
  font-size: 0.7rem;
  font-weight: 900;
  letter-spacing: 0.02em;
  text-transform: uppercase;
}

.equation--multiline {
  line-height: 1.65;
  white-space: nowrap;
}

.formula-card--wide {
  grid-column: 1 / -1;
}

.coefficient-tables {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.coefficient-tables .table-scroll {
  margin-top: 0;
}

.coefficient-table {
  min-width: 360px;
}

.coefficient-table caption {
  padding: 12px 14px;
  background: var(--surface-soft);
  font-weight: 850;
  text-align: left;
}

.coefficient-table th:first-child,
.coefficient-table td:first-child,
.coefficient-table th:last-child,
.coefficient-table td:last-child {
  width: auto;
  text-align: left;
}

.body-fat-formulas .citation-entry {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
}

.reference-panel .source-type {
  margin-bottom: 8px;
}

.reference-panel cite {
  display: block;
}

.reference-panel cite + a,
.reference-panel a + a,
.reference-panel a + cite {
  margin-left: 8px;
}

.reference-panel a + cite {
  margin-top: 12px;
  margin-left: 0;
}

.calculator-audience-warning {
  margin: 0 0 18px;
}

.energy-tool {
  grid-template-columns: minmax(0, 1.15fr) minmax(310px, 0.85fr);
}

.calculator-stage {
  display: grid;
  gap: 20px;
  border-top: 1px solid var(--line);
  padding-top: 24px;
}

.calculator-stage:first-child {
  border-top: 0;
  padding-top: 0;
}

.stage-heading {
  display: flex;
  align-items: flex-start;
  gap: 12px;
}

.stage-heading > span {
  display: grid;
  width: 28px;
  height: 28px;
  flex: 0 0 auto;
  place-items: center;
  border-radius: 50%;
  background: var(--accent-strong);
  color: white;
  font-size: 0.82rem;
  font-weight: 900;
}

.stage-heading h2 {
  font-size: 1.2rem;
}

.stage-heading p {
  margin: 5px 0 0;
  color: var(--muted);
  font-size: 0.88rem;
}

.choice-fieldset[hidden] {
  display: none;
}

.choice-grid--adjustments {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.result-value--energy {
  font-size: clamp(2.15rem, 5vw, 3.8rem);
}

.result-section-title {
  margin-top: 24px;
  font-size: 1rem;
}

.result-stats--stacked {
  grid-template-columns: minmax(0, 1fr);
}

.macro-results {
  display: grid;
  gap: 9px;
  margin: 10px 0 0;
}

.macro-results > div {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  border: 1px solid var(--line);
  border-radius: var(--control-radius);
  padding: 13px 14px;
  background: var(--surface-soft);
}

.macro-results dt {
  color: var(--muted);
  font-size: 0.82rem;
  font-weight: 850;
  text-transform: uppercase;
}

.macro-results dd {
  display: grid;
  margin: 0;
  text-align: right;
}

.macro-results dd span {
  color: var(--muted);
  font-size: 0.8rem;
}

.energy-result .reliability-warning {
  margin-top: 12px;
}

@media (max-width: 860px) {
  .tool-shell {
    grid-template-columns: minmax(0, 1fr);
  }

  .result-panel {
    min-height: auto;
  }

  .coefficient-tables {
    grid-template-columns: minmax(0, 1fr);
  }
}

@media (max-width: 680px) {
  .form-row,
  .method-grid,
  .formula-grid,
  .tool-grid,
  .result-stats,
  .choice-grid,
  .choice-grid--methods,
  .measurement-grid {
    grid-template-columns: minmax(0, 1fr);
  }

  .choice-grid--adjustments {
    grid-template-columns: minmax(0, 1fr);
  }

  .table-heading {
    align-items: start;
    flex-direction: column;
    gap: 4px;
  }

  .inline-actions .button {
    width: 100%;
  }

  .macro-results > div {
    align-items: flex-start;
    flex-direction: column;
  }

  .macro-results dd {
    text-align: left;
  }
}