/* Sources / reference standard page. Mobile-first. */
body.page-sources { margin: 0; background: var(--tgs-bg, #FAF8FF); color: var(--tgs-ink, #1B1030); font-family: var(--tgs-font-body, Inter, system-ui, sans-serif); }
.page-sources *, .page-sources *::before, .page-sources *::after { box-sizing: border-box; }
.sourceContainer { width: min(80rem, 100% - 2 * var(--tgs-gutter, 1rem)); margin-inline: auto; }
.page-sources h1, .page-sources h2, .page-sources h3 { margin: 0; font-family: var(--tgs-font-head, 'Cormorant Garamond', Georgia, serif); font-weight: 500; line-height: 1.08; text-wrap: balance; }
.page-sources h1 { margin: 1rem 0; color: #fff; font-size: var(--tgs-step-4, clamp(2.5rem, 1.8rem + 3.5vw, 5.5rem)); }
.page-sources h2 { margin-bottom: .75rem; font-size: var(--tgs-step-3, clamp(2rem, 1.6rem + 2vw, 3.5rem)); }
.page-sources h3 { font-size: var(--tgs-step-1, 1.5rem); }
.page-sources p { margin: 0; line-height: 1.7; overflow-wrap: anywhere; }
.sourceGradientWord { font-style: italic; color: var(--tgs-violet-700, #5B21B6); }
.sourceKicker { font-size: .75rem; font-weight: 800; letter-spacing: .16em; color: var(--tgs-violet-700, #5B21B6); }
.sourceVisuallyHidden { position: absolute; width: 1px; height: 1px; margin: -1px; overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0; }

.sourceButton { display: inline-flex; align-items: center; justify-content: center; min-height: var(--tgs-tap, 2.75rem); padding: .75rem 1.5rem; border: 1px solid var(--tgs-violet-700, #5B21B6); border-radius: var(--tgs-r-pill, 999px); background: #fff; color: var(--tgs-violet-800, #3B0A7A); font: 700 1rem/1.2 var(--tgs-font-body, Inter, sans-serif); text-align: center; text-decoration: none; transition: transform .25s var(--tgs-ease, ease), box-shadow .25s var(--tgs-ease, ease); }
.sourceButtonPrimary { border-color: transparent; background: var(--tgs-grad-primary, linear-gradient(135deg, #3B0A7A, #5B21B6 50%, #8B5CF6)); color: #fff; }
.sourceHero .sourceButtonSecondary, .sourceClosing .sourceButtonSecondary { border-color: rgba(255, 255, 255, .6); background: transparent; color: #fff; }
.sourceButton:focus-visible, .sourceFilterChip:focus-visible, .sourceExternalLink:focus-visible, .sourceContents a:focus-visible, .sourceFaqItem summary:focus-visible { outline: 3px solid var(--tgs-violet-500, #8B5CF6); outline-offset: 3px; }
.sourceHeroActions, .sourceActions { display: flex; flex-wrap: wrap; gap: .75rem; margin-top: 1.5rem; }
.sourceHeroActions .sourceButton, .sourceActions .sourceButton { flex: 1 1 12rem; }

/* hero */
.sourceHero { background: var(--tgs-grad-dark, linear-gradient(160deg, #150A2E, #2A0F5C 60%, #4C1D95)); color: #fff; padding: 3.5rem 0; }
.sourceHeroLayout { display: grid; grid-template-columns: minmax(0, 1fr); gap: 2rem; align-items: center; }
.sourceHero .sourceKicker { color: var(--tgs-orchid, #C084FC); }
.sourceHero .sourceGradientWord { color: var(--tgs-violet-200, #DDD6FE); }
.sourceHeroCopy p { max-width: 36rem; color: rgba(255, 255, 255, .9); font-size: 1.0625rem; }
.sourceHeroFigure { margin: 0; overflow: hidden; border-radius: var(--tgs-r-lg, 1.75rem); }
.sourceHeroFigure img, .sourceBandImage, .sourceAnatomyFigure img { display: block; width: 100%; height: auto; }
.sourceHeroFigure img { aspect-ratio: 4 / 3; object-fit: cover; }

/* standard band */
.sourceBand { padding: 3rem 0; background: var(--tgs-violet-50, #F6F2FF); }
.sourceBandInner { display: grid; grid-template-columns: minmax(0, 1fr); gap: 1.5rem; align-items: center; width: min(80rem, 100% - 2 * var(--tgs-gutter, 1rem)); margin-inline: auto; }
.sourceBandCopy p { max-width: 34rem; color: var(--tgs-muted, #6B6485); }
.sourceBandImage { max-height: 26rem; object-fit: cover; border-radius: var(--tgs-r-lg, 1.75rem); }

/* sections */
.sourceSection { padding: 3rem 0; }
.sourceSectionAlt { background: var(--tgs-violet-50, #F6F2FF); }
.sourceSectionHeading { margin-bottom: 1.5rem; }
.sourceSectionHeading p { max-width: 38rem; color: var(--tgs-muted, #6B6485); }
.sourceClaimGrid, .sourceStepsGrid, .sourceCardGrid { display: grid; grid-template-columns: minmax(0, 1fr); gap: 1rem; }
.sourceClaimCard, .sourceCard, .sourceStep { position: relative; display: grid; align-content: start; gap: .5rem; min-width: 0; padding: 1.25rem; border: 1px solid var(--tgs-line, #E7E0F7); border-radius: var(--tgs-r-md, 1.25rem); background: #fff; }
.sourceClaimNumber, .sourceStepNumber { font-size: .8125rem; font-weight: 700; letter-spacing: .12em; color: var(--tgs-violet-600, #7C3AED); }
.sourceClaimCard p, .sourceCard p, .sourceStep p { color: var(--tgs-muted, #6B6485); font-size: .9375rem; }

/* library + contents */
.sourceLibraryLayout { display: grid; grid-template-columns: minmax(0, 1fr); gap: 1.25rem; align-items: start; }
.sourceContents h3 { margin-bottom: .5rem; font-size: 1.25rem; }
.sourceContents nav { display: flex; gap: .5rem; overflow-x: auto; padding-bottom: .25rem; }
.sourceContents a { flex: 0 0 auto; display: inline-flex; align-items: center; min-height: var(--tgs-tap, 2.75rem); padding: .4rem .9rem; border: 1px solid var(--tgs-line, #E7E0F7); border-radius: var(--tgs-r-pill, 999px); background: #fff; color: var(--tgs-violet-800, #3B0A7A); font-size: .9375rem; font-weight: 600; text-decoration: none; }
.sourceContents a.is-active { border-color: var(--tgs-violet-600, #7C3AED); background: var(--tgs-violet-100, #EDE9FE); }
.sourceLibrary { min-width: 0; }
.sourceFilterBar { display: flex; flex-wrap: wrap; gap: .5rem; margin-bottom: .75rem; }
.sourceFilterChip { min-height: var(--tgs-tap, 2.75rem); padding: .5rem 1rem; border: 1px solid var(--tgs-violet-200, #DDD6FE); border-radius: var(--tgs-r-pill, 999px); background: #fff; color: var(--tgs-violet-800, #3B0A7A); font: 600 .9375rem var(--tgs-font-body, Inter, sans-serif); cursor: pointer; }
.sourceFilterChip[aria-pressed="true"] { border-color: transparent; background: var(--tgs-grad-primary, linear-gradient(135deg, #3B0A7A, #5B21B6 50%, #8B5CF6)); color: #fff; }
.sourceCount { margin-bottom: 1rem; color: var(--tgs-muted, #6B6485); font-size: .9375rem; }
.sourceCard[hidden] { display: none; }
.sourcePublisher { justify-self: start; padding: .1rem .6rem; border-radius: var(--tgs-r-pill, 999px); background: var(--tgs-violet-100, #EDE9FE); color: var(--tgs-violet-800, #3B0A7A); font-size: .75rem; font-weight: 800; letter-spacing: .08em; }
.sourceCard .sourceClaimNumber { position: absolute; top: 1.25rem; right: 1.25rem; }
.sourceExternalLink { display: inline-flex; align-items: center; gap: .35rem; justify-self: start; min-height: var(--tgs-tap, 2.75rem); color: var(--tgs-violet-700, #5B21B6); font-weight: 700; text-decoration: underline; text-underline-offset: .25em; }

/* anatomy, steps, faq */
.sourceAnatomy { display: grid; grid-template-columns: minmax(0, 1fr); gap: 1.5rem; align-items: center; }
.sourceAnatomyFigure { margin: 0; overflow: hidden; border: 1px solid var(--tgs-line, #E7E0F7); border-radius: var(--tgs-r-lg, 1.75rem); background: #fff; }
.sourceAnatomyFigure figcaption { padding: .75rem 1.25rem; color: var(--tgs-muted, #6B6485); font-size: .9375rem; }
.sourceFaqList { display: grid; gap: .6rem; max-width: 52rem; }
.sourceFaqItem { border: 1px solid var(--tgs-line, #E7E0F7); border-radius: var(--tgs-r-md, 1.25rem); background: #fff; }
.sourceFaqItem summary { display: flex; align-items: center; min-height: 3.25rem; padding: .5rem 1.25rem; font-weight: 600; cursor: pointer; }
.sourceFaqItem p { padding: 0 1.25rem 1.1rem; color: var(--tgs-muted, #6B6485); }

/* closing */
.sourceClosing { position: relative; isolation: isolate; overflow: hidden; padding: 4rem 0; background: var(--tgs-violet-950, #150A2E); color: #fff; }
.sourceClosingImage { position: absolute; inset: 0; z-index: -2; width: 100%; height: 100%; object-fit: cover; }
.sourceClosing::after { content: ""; position: absolute; inset: 0; z-index: -1; background: linear-gradient(0deg, rgba(21, 10, 46, .9), rgba(21, 10, 46, .55)); }
.sourceClosing h2 { color: #fff; }
.sourceClosing .sourceKicker { color: var(--tgs-orchid, #C084FC); }
.sourceClosing .sourceGradientWord { color: var(--tgs-violet-200, #DDD6FE); }
.sourceClosingContent p { max-width: 36rem; color: rgba(255, 255, 255, .9); }

.sourceReveal { opacity: 0; transform: translateY(14px); transition: opacity .5s var(--tgs-ease, ease), transform .5s var(--tgs-ease, ease); }
.sourceReveal.isIn { opacity: 1; transform: none; }

@media (min-width: 480px) {
  .sourceClaimGrid, .sourceCardGrid { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (min-width: 768px) {
  .sourceHero { padding: 5rem 0; }
  .sourceHeroLayout, .sourceBandInner, .sourceAnatomy { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 3rem; }
  .sourceBand, .sourceSection { padding: 4.5rem 0; }
  .sourceClaimGrid, .sourceStepsGrid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}
@media (min-width: 1024px) {
  .sourceLibraryLayout { grid-template-columns: 14rem minmax(0, 1fr); gap: 2.5rem; }
  .sourceContents { position: sticky; top: calc(var(--tgs-nav-h, 5rem) + 1rem); padding-left: 1rem; border-left: 1px solid var(--tgs-line, #E7E0F7); }
  .sourceContents nav { flex-direction: column; overflow: visible; gap: .25rem; }
  .sourceContents a { border: 0; background: transparent; border-radius: var(--tgs-r-sm, .75rem); }
  .sourceContents a.is-active { background: var(--tgs-violet-100, #EDE9FE); }
}
@media (min-width: 1280px) {
  .sourceCardGrid { grid-template-columns: repeat(3, minmax(0, 1fr)); }
}
@media (hover: hover) {
  .sourceButton:hover { transform: translateY(-2px); box-shadow: var(--tgs-shadow-sm, 0 6px 20px rgba(91, 33, 182, .08)); }
  .sourceCard:hover { border-color: var(--tgs-violet-500, #8B5CF6); }
}
@media (prefers-reduced-motion: reduce) {
  .sourceButton, .sourceReveal { transition: none; }
}