/* learning.css — page-private layout extracted from styles.css. Shared tokens, nav, hero runtime, CTA/FAQ contract stay in styles.css. */
/* Learning V3: one reliable article experience, regardless of available photography. */
.learning-guide:not(.hub-experience) .official-hero--product{
  display: grid;
  min-height: 0;
  max-height: none;
  overflow: visible;
  border-bottom: 1px solid var(--surface-line);
  background:
    radial-gradient(circle at 94% 12%, rgb(152 90 32 / 9%), transparent 22rem),
    var(--page-canvas);
  color: var(--ink);
  text-align: left;
}
.learning-guide:not(.hub-experience) .official-hero--product::after{
  display: none;
}
.learning-guide:not(.hub-experience) .official-hero--product .official-hero__media{
  display: none;
}
.learning-guide:not(.hub-experience) .official-hero--product .official-hero__inner{
  display: block;
  width: var(--learning-rail-width);
  max-width: none;
  margin-inline: auto;
  padding: clamp(7rem, 10vw, 10rem) 0 clamp(4.5rem, 6vw, 6.5rem);
  color: var(--ink);
  text-align: left;
  opacity: 1;
  transform: none;
}
.learning-guide:not(.hub-experience) .official-hero--product .label{
  display: block;
  margin-bottom: 1.25rem;
  color: var(--copper);
}
.learning-guide:not(.hub-experience) .official-hero--product h1{
  max-width: 17ch;
  margin: 0;
  color: var(--ink);
  font-size: clamp(3.35rem, 5.7vw, 6.1rem);
  line-height: 0.94;
  letter-spacing: -0.05em;
  text-wrap: pretty;
}
.learning-guide:not(.hub-experience) .official-hero--product p{
  max-width: 58ch;
  margin: 1.25rem 0 0;
  color: var(--ink-soft);
  font-size: clamp(1.05rem, 1.3vw, 1.2rem);
  line-height: 1.65;
}
.learning-guide:not(.hub-experience) .official-hero--product .page-actions{
  justify-content: flex-start;
  margin: 1.5rem 0 0;
}
.learning-guide:not(.hub-experience) .official-hero--product .page-actions .button{
  min-height: 0;
  padding: 0.25rem 0;
  border: 0;
  border-bottom: 1px solid currentColor;
  border-radius: 0;
  background: transparent;
  color: var(--ink);
  font-size: 0.9rem;
}
.learning-guide:not(.hub-experience) :is(.learning-section, .study-panel, .evidence-key, .comparison-visual, .research-spotlight, .safety-panel){
  min-height: 0;
  padding-top: clamp(3.5rem, 5vw, 5.5rem);
  padding-bottom: clamp(3.5rem, 5vw, 5.5rem);
}
.learning-guide--evidence .study-panel,
.learning-guide--minimal-media .study-panel{
  display: block;
  max-width: var(--learning-rail-width);
  margin-inline: auto;
}
.learning-guide--evidence .study-panel__copy,
.learning-guide--minimal-media .study-panel__copy{
  width: min(100%, 74ch);
  max-width: none;
  padding-inline: 0;
}
.learning-guide:not(.hub-experience) .product-closing-cta--framed{
  /*
    Learning-only closing CTA: text-led decision panel.
    No photograph, so do not inherit the product 560px / full-rail photo frame.
  */
  --cta-frame-min-height: 0;
  --cta-content-padding: clamp(1.75rem, 3vw, 2.5rem);
  --cta-frame-columns: minmax(0, 1fr);
  --cta-frame-radius: clamp(1rem, 1.6vw, 1.35rem);

  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
  width: min(48rem, calc(100% - var(--content-rail-inset)));
  max-width: min(48rem, calc(100% - var(--content-rail-inset)));
  min-height: 0;
  height: auto;
  margin-inline: auto;
  overflow-x: clip;
  overflow-y: visible;
  text-align: center;
}
.learning-guide:not(.hub-experience) .product-closing-cta--framed .product-closing-cta__media{
  display: none;
}
.learning-guide:not(.hub-experience) .product-closing-cta--framed .product-closing-cta__content{
  min-height: 0;
  height: auto;
  align-items: center;
  justify-content: flex-start;
  padding: var(--cta-content-padding);
  background: var(--cta-card-surface);
  text-align: center;
}
/* --- Learning v2: source-led editorial guides --- */
.product-experience .official-hero--learning-hub{
  --hero-image: url("assets/heroes/learning/longevity-reading-session.webp");
  --hero-position: center 48%;
}
.learning-guide{
  --learning-width: var(--learning-rail-width);
  --product-content-width: var(--content-rail-width);
  --product-cta-entry-space: clamp(2.4rem, 3vw, 3.2rem);
  --product-section-line: rgb(0 0 0 / 14%);
  background: var(--page-canvas);
}
/* Learning heroes use the shared product centered treatment (not a left editorial column). */
.learning-guide:not(.hub-experience) .official-hero--product .official-hero__inner{
  width: min(900px, calc(100% - 2rem));
  max-width: none;
  margin-inline: auto;
  padding-inline: 1rem;
  text-align: center;
}
.learning-guide:not(.hub-experience) .official-hero--product h1,
.learning-guide:not(.hub-experience) .official-hero--product p{
  margin-inline: auto;
}
.learning-guide:not(.hub-experience) .official-hero--product h1{
  /* ch tracks font size so short titles like "TBI evidence." stay one line */
  max-width: min(28ch, 100%);
  font-size: clamp(3rem, 5.6vw, 5.4rem);
  line-height: 0.98;
  text-wrap: unset;
}
.learning-guide:not(.hub-experience) .official-hero--product p{
  max-width: 46ch;
}
.learning-guide:not(.hub-experience) .official-hero--product .page-actions{
  justify-content: center;
}
/* Evidence long-form: shorter hero + study emphasis; same Learning rail width */
.learning-guide--evidence{
  --learning-width: var(--learning-rail-width);
  --product-content-width: var(--learning-rail-width);
}
.learning-guide--evidence .official-hero--product{
  min-height: clamp(20rem, 48vh, 32rem);
}
.learning-guide--evidence .official-hero--product h1{
  max-width: min(28ch, 100%);
  margin-inline: auto;
  font-size: clamp(3rem, 5.4vw, 5.2rem);
  text-wrap: unset;
}
.learning-guide--evidence .official-hero--product p{
  max-width: 48ch;
  margin-inline: auto;
}
.learning-guide--evidence .learning-intro__copy,
.learning-guide--evidence .study-panel__copy,
.learning-guide--evidence .learning-section__header p,
.learning-guide--evidence .learning-faq__items{
  max-width: 68ch;
  text-align: justify;
  text-justify: inter-word;
}
.learning-guide--evidence .learning-evidence-brief{
  gap: 0.85rem;
}
.learning-guide--evidence .learning-evidence-brief p{
  padding-block: 0.85rem;
}
.learning-guide--evidence .learning-evidence-brief p:first-child{
  border-top: 0;
  padding-top: 0;
}
/* Condition-evidence index: directory rows, not a second Learning hub */
.learning-intro,
.study-panel,
.learning-section,
.comparison-visual,
.research-spotlight,
.safety-panel{
  width: var(--learning-width);
  margin-inline: auto;
}
.learning-intro{
  display: grid;
  grid-template-columns: minmax(280px, 1.15fr) minmax(0, 1fr);
  gap: clamp(2rem, 6vw, 5rem);
  padding: clamp(4.5rem, 7vw, 6.5rem) 0;
  border-bottom: 1px solid rgba(24, 21, 18, 0.12);
}
.learning-intro h2,
.learning-section__header h2,
.comparison-visual > header h2,
.study-panel__copy h2,
.research-spotlight h2,
.safety-panel__title h2{
  max-width: min(28ch, 100%);
  margin: 0.55rem 0 1rem;
  font-size: clamp(2.2rem, 3.4vw, 3.4rem);
  line-height: 1.08;
  letter-spacing: -0.02em;
  text-wrap: unset;
}
.learning-intro__copy{
  max-width: 64ch;
}
.study-panel__copy h2{
  max-width: min(28ch, 100%);
  font-size: clamp(2.2rem, 3.2vw, 3.2rem);
}
.learning-intro__copy p,
.learning-section__header p,
.study-panel__copy > p,
.research-spotlight__copy > p,
.comparison-visual p{
  margin: 0 0 1.2rem;
  color: rgba(24, 21, 18, 0.7);
  font-size: clamp(1rem, 1.25vw, 1.15rem);
  line-height: 1.78;
}
.learning-intro__copy p,
.learning-section__header p,
.study-panel__copy > p,
.research-spotlight__copy > p{
  text-align: justify;
  text-justify: inter-word;
}
.hub-selector--learning{
  width: var(--learning-width);
}
.hub-selector--learning .family-selector__intro h2{
  max-width: none;
  font-size: clamp(2.6rem, 4.4vw, 4.5rem);
}
.hub-selector--learning .family-selector__intro p{
  max-width: 62ch;
  margin-inline: auto;
  color: rgba(24, 21, 18, 0.68);
  line-height: 1.7;
}
.learning-comparison-media{
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.4rem;
  aspect-ratio: 16 / 9;
  padding: 0.4rem;
}
.hub-selector--learning .learning-comparison-media img{
  min-width: 0;
  height: 100%;
  aspect-ratio: auto;
  object-fit: contain;
}
.mechanism-strip,
.learning-flow,
.learning-steps,
.evidence-ladder{
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  border-top: 1px solid rgba(24, 21, 18, 0.14);
  border-bottom: 1px solid rgba(24, 21, 18, 0.14);
}
.learning-flow{
  position: relative;
  width: var(--learning-width);
  grid-template-columns: repeat(3, minmax(0, 1fr));
  margin: 0 auto clamp(3.5rem, 6vw, 5.5rem);
  background: rgba(255, 250, 242, 0.42);
}
.learning-flow article{
  position: relative;
}
.learning-flow article > span{
  display: inline-grid;
  width: 2rem;
  height: 2rem;
  place-items: center;
  border: 1px solid rgba(184, 127, 69, 0.48);
  border-radius: 50%;
}
.mechanism-strip article,
.learning-flow article,
.learning-steps article,
.evidence-ladder article{
  padding: clamp(1.5rem, 3vw, 2.5rem);
  border-left: 1px solid rgba(24, 21, 18, 0.12);
}
.mechanism-strip article:first-child,
.learning-flow article:first-child,
.learning-steps article:first-child,
.evidence-ladder article:first-child{
  border-left: 0;
}
.mechanism-strip article > span,
.learning-flow article > span,
.learning-steps article > span,
.evidence-ladder article > span,
.comparison-visual__items article > div > span{
  color: var(--copper);
  font-family: var(--font-glacial);
  font-size: 0.75rem;
  font-weight: 800;
  letter-spacing: 0.13em;
  text-transform: uppercase;
}
.mechanism-strip h2,
.mechanism-strip h3,
.learning-flow h2,
.learning-steps h3,
.evidence-ladder h3{
  margin: 1.5rem 0 0.7rem;
  font-size: clamp(1.45rem, 2vw, 2rem);
  line-height: 1.12;
}
.mechanism-strip p,
.learning-flow p,
.learning-steps p,
.evidence-ladder p{
  margin: 0;
  color: rgba(24, 21, 18, 0.68);
  line-height: 1.68;
}
.study-panel{
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: clamp(2.5rem, 7vw, 7rem);
  align-items: center;
  padding: clamp(4.5rem, 7vw, 6.5rem) 0;
}
.study-panel--reverse .study-panel__media{
  order: 2;
}
.study-panel__media{
  margin: 0;
}
.study-panel__media img{
  width: 100%;
  aspect-ratio: 4 / 3;
  object-fit: cover;
  border-radius: 6px;
}
.study-panel__media figcaption{
  margin-top: 0.8rem;
  color: rgba(24, 21, 18, 0.55);
  font-size: 0.86rem;
  line-height: 1.5;
}
.learning-steps--plain article{
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 0.85rem;
  align-items: start;
}
.learning-steps--plain article h3{
  display: none;
}
.learning-section{
  padding: clamp(4.5rem, 7vw, 6.5rem) 0;
}
.learning-section--tint{
  width: 100%;
  padding-inline: max(calc((100% - 1240px) / 2), clamp(1rem, 4vw, 4rem));
  background: var(--page-canvas);
}
.learning-section__header{
  max-width: 780px;
  margin-bottom: clamp(2.5rem, 5vw, 4rem);
}
.learning-split-list__mark{
  display: inline-flex;
  padding: 0.35rem 0.65rem;
  border: 1px solid currentColor;
  border-radius: 999px;
  color: var(--clay);
  font-family: var(--font-glacial);
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.1em;
  text-transform: uppercase;
}
.learning-claim-matrix{
  display: grid;
  overflow: hidden;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  border: 1px solid var(--card-line);
  border-radius: 8px;
  background: var(--card-surface);
}
.learning-claim-matrix article{
  padding: clamp(2rem, 4vw, 3rem);
}
.learning-claim-matrix article + article{
  border-left: 1px solid var(--card-line);
  background: var(--card-surface);
}
.learning-claim-matrix .learning-split-list__mark{
  border: 0;
  padding: 0;
  border-radius: 0;
}
.learning-claim-matrix h3{
  max-width: 17ch;
  margin: 1.25rem 0 0.85rem;
  font-size: clamp(1.75rem, 2.5vw, 2.45rem);
  font-weight: 400;
  line-height: 1.1;
}
.learning-claim-matrix p{
  max-width: 50ch;
  margin: 0;
  color: rgba(24, 21, 18, 0.68);
  line-height: 1.65;
}
.mechanism-strip--three{
  grid-template-columns: repeat(3, minmax(0, 1fr));
}
.research-spotlight{
  display: grid;
  grid-template-columns: minmax(180px, 0.42fr) minmax(0, 1.58fr);
  gap: clamp(2rem, 7vw, 7rem);
  align-items: center;
  padding: clamp(4.5rem, 7vw, 6.5rem) 0;
  border-top: 1px solid rgba(24, 21, 18, 0.14);
}
.research-spotlight__number{
  color: rgba(191, 124, 53, 0.25);
  font-size: clamp(8rem, 18vw, 16rem);
  line-height: 0.8;
  text-align: center;
}
.mechanism-strip{
  width: var(--learning-width);
  margin: 0 auto clamp(3.5rem, 6vw, 5.5rem);
}
.evidence-ladder{
  margin-top: clamp(2rem, 5vw, 4rem);
}
.safety-panel{
  display: grid;
  grid-template-columns: minmax(260px, 0.72fr) minmax(0, 1.28fr);
  gap: clamp(2.5rem, 8vw, 8rem);
  padding: clamp(4.5rem, 7vw, 6.5rem) 0;
}
.safety-panel--with-media{
  grid-template-columns: minmax(380px, 0.95fr) minmax(0, 1.05fr);
  align-items: start;
}
.safety-panel__media{
  margin: clamp(2rem, 4vw, 3rem) 0 0;
}
.safety-panel__media img{
  width: 100%;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  border-radius: 6px;
}
.safety-panel__media figcaption{
  max-width: 54ch;
  margin-top: 0.8rem;
  color: rgba(24, 21, 18, 0.55);
  font-size: 0.86rem;
  line-height: 1.5;
}
.safety-panel ol{
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid rgba(24, 21, 18, 0.14);
}
.safety-panel li{
  display: grid;
  grid-template-columns: 2.5rem minmax(0, 1fr);
  gap: 1rem;
  padding: 1.1rem 0;
  border-bottom: 1px solid rgba(24, 21, 18, 0.14);
}
.safety-panel li span{
  color: var(--copper);
  font-family: var(--font-glacial);
  font-size: 0.75rem;
  font-weight: 800;
}
.safety-panel li p{
  margin: 0;
  color: rgba(24, 21, 18, 0.7);
  line-height: 1.6;
}
.comparison-visual{
  padding: clamp(4.5rem, 7vw, 6.5rem) 0;
}
.comparison-visual > header{
  max-width: 780px;
  margin-bottom: clamp(2.5rem, 5vw, 4rem);
}
.comparison-visual__items{
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1rem;
}
.comparison-visual__items article{
  overflow: hidden;
  border: 1px solid var(--card-line);
  border-radius: 6px;
  background: var(--card-surface);
}
.comparison-visual__items figure{
  margin: 0;
  overflow: hidden;
  background: var(--media-frame-surface);
}
.comparison-visual__items img{
  width: 100%;
  aspect-ratio: 16 / 10;
  object-fit: cover;
}
.comparison-visual__items article > div{
  padding: clamp(1.5rem, 3vw, 2.5rem);
}
.comparison-visual__items h3{
  margin: 0.65rem 0 0.8rem;
  font-size: clamp(1.8rem, 2.7vw, 2.7rem);
}
.comparison-decision-flow .safety-panel__title{
  position: sticky;
  top: 8rem;
  align-self: start;
}
@media (max-width: 900px) {.learning-intro,
.study-panel,
.research-spotlight,
.safety-panel{
    grid-template-columns: 1fr;
    gap: 2rem;
  }
.comparison-decision-flow .safety-panel__title{
    position: static;
  }
.study-panel--reverse .study-panel__media{
    order: 0;
  }
.mechanism-strip,
.learning-flow,
.learning-steps,
.evidence-ladder,
.mechanism-strip--three{
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
.mechanism-strip article:nth-child(3),
.learning-flow article:nth-child(3),
.learning-steps article:nth-child(3),
.evidence-ladder article:nth-child(3){
    border-left: 0;
  }
.research-spotlight__number{
    text-align: left;
  }}
/* --- Experts v2: field education and responsible guidance --- */
.experts-guide{
  --experts-width: var(--learning-rail-width);
}
.experts-credentials,
.experts-collection,
.experts-story,
.experts-field,
.experts-boundary{
  width: var(--experts-width);
  margin-inline: auto;
}
.experts-story__media,
.experts-field__media{
  margin: 0;
}
.experts-story__media figcaption,
.experts-field__media figcaption{
  margin-top: 0.8rem;
  color: rgba(24, 21, 18, 0.54);
  font-size: 0.84rem;
  line-height: 1.5;
}
.experts-credentials{
  display: grid;
  grid-template-columns: 0.65fr 1.1fr 1fr;
  gap: clamp(2rem, 5vw, 5rem);
  padding: clamp(2.6rem, 5vw, 4rem) 0;
  border-top: 1px solid rgba(24, 21, 18, 0.14);
  border-bottom: 1px solid rgba(24, 21, 18, 0.14);
}
.experts-credentials article > span,
.experts-responsibility-matrix article > span{
  color: var(--clay);
  font-family: var(--font-glacial);
  font-size: 0.72rem;
  font-weight: 800;
  letter-spacing: 0.12em;
  text-transform: uppercase;
}
.experts-credentials strong{
  display: block;
  margin: 0.75rem 0 0.45rem;
  font-size: clamp(1.65rem, 2.3vw, 2.4rem);
  font-weight: 400;
  line-height: 1.05;
}
.experts-credentials p{
  max-width: 34ch;
  margin: 0;
  color: rgba(24, 21, 18, 0.62);
  line-height: 1.62;
}
.experts-collection{
  padding: clamp(4.5rem, 7vw, 6.5rem) 0;
}
.experts-collection__header{
  max-width: 760px;
  margin-bottom: clamp(2.5rem, 5vw, 3.5rem);
}
.experts-collection__header h2{
  max-width: 16ch;
  margin: 0.55rem 0 1rem;
  font-size: clamp(2.4rem, 3.8vw, 3.6rem);
  line-height: 1.05;
  letter-spacing: -0.025em;
}
.experts-collection__header p{
  margin: 0;
  color: rgba(24, 21, 18, 0.68);
  font-size: clamp(1rem, 1.2vw, 1.12rem);
  line-height: 1.72;
}
.experts-profiles{
  display: grid;
  gap: clamp(2rem, 4vw, 3rem);
}
.experts-person{
  display: grid;
  grid-template-columns: 7.5rem minmax(0, 1fr);
  gap: clamp(1.25rem, 3vw, 2rem);
  align-items: start;
  padding: clamp(1.5rem, 3vw, 2rem) 0;
  border-top: 1px solid rgba(24, 21, 18, 0.14);
}
.experts-person:last-of-type{
  border-bottom: 1px solid rgba(24, 21, 18, 0.14);
}
.experts-person > img{
  width: 7.5rem;
  height: 7.5rem;
  border-radius: 50%;
  object-fit: cover;
  object-position: center 20%;
}
.experts-person h3{
  margin: 0.35rem 0 0.85rem;
  font-size: clamp(1.7rem, 2.4vw, 2.25rem);
  font-weight: 400;
  line-height: 1.1;
}
.experts-person > div > p{
  margin: 0 0 1rem;
  color: rgba(24, 21, 18, 0.69);
  line-height: 1.72;
}
.experts-person ul{
  display: grid;
  gap: 0.55rem;
  margin: 0 0 1rem;
  padding-left: 1.15rem;
  color: rgba(24, 21, 18, 0.66);
  line-height: 1.55;
}
.experts-story{
  display: grid;
  grid-template-columns: minmax(0, 1.04fr) minmax(360px, 0.96fr);
  gap: clamp(3rem, 8vw, 8rem);
  align-items: center;
  padding: clamp(4.5rem, 7vw, 6.5rem) 0;
}
.experts-story__media img{
  width: 100%;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  border-radius: 7px;
  box-shadow: 0 28px 80px rgba(67, 43, 24, 0.12);
}
.experts-story__copy h2,
.experts-field__copy h2,
.experts-boundary h2{
  max-width: min(28ch, 100%);
  margin: 0.55rem 0 1rem;
  font-size: clamp(2.2rem, 3.4vw, 3.4rem);
  line-height: 1.08;
  letter-spacing: -0.025em;
  text-wrap: unset;
}
.experts-title-line{
  display: block;
}
.experts-story__copy > p,
.experts-field__copy > p{
  margin: 0 0 1.15rem;
  color: rgba(24, 21, 18, 0.69);
  font-size: clamp(1rem, 1.2vw, 1.13rem);
  line-height: 1.76;
}
.experts-topic-list{
  margin-top: 2rem;
  border-top: 1px solid rgba(24, 21, 18, 0.14);
}
.experts-profile{
  display: grid;
  grid-template-columns: 4.5rem minmax(0, 1fr);
  gap: 1rem;
  align-items: center;
  margin: 1.5rem 0 0;
  padding: 1rem 0;
  border-top: 1px solid rgba(24, 21, 18, 0.14);
  border-bottom: 1px solid rgba(24, 21, 18, 0.14);
}
.experts-profile img{
  width: 4.5rem;
  height: 4.5rem;
  border-radius: 50%;
  object-fit: cover;
  object-position: center 30%;
}
.experts-profile p{
  margin: 0;
  color: rgba(24, 21, 18, 0.63);
  font-size: 0.9rem;
  line-height: 1.5;
}
.experts-profile strong,
.experts-profile span{
  display: block;
}
.experts-profile strong{
  margin-bottom: 0.2rem;
  color: var(--ink);
  font-family: var(--font-glacial);
}
.experts-topic-list > div{
  display: grid;
  grid-template-columns: 2.4rem minmax(0, 1fr);
  gap: 1rem;
  padding: 1rem 0;
  border-bottom: 1px solid rgba(24, 21, 18, 0.14);
}
.experts-topic-list span{
  color: var(--copper);
  font-family: var(--font-glacial);
  font-size: 0.72rem;
  font-weight: 800;
}
.experts-topic-list p{
  margin: 0;
  color: rgba(24, 21, 18, 0.67);
  line-height: 1.58;
}
.experts-field{
  display: grid;
  grid-template-columns: minmax(320px, 0.78fr) minmax(0, 1.22fr);
  gap: clamp(3rem, 8vw, 8rem);
  align-items: center;
  padding: clamp(3rem, 6vw, 5rem);
  border-radius: 8px;
  background: var(--card-surface);
}
.experts-field__media img{
  width: 100%;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  border-radius: 6px;
}
.experts-field__copy .text-link{
  display: inline-block;
  margin-top: 1rem;
  color: var(--clay);
  font-family: var(--font-glacial);
  font-weight: 700;
  letter-spacing: 0.02em;
  text-decoration: none;
}
.experts-field__copy .text-link:hover{
  color: var(--copper);
}
.experts-boundary{
  padding: clamp(4.5rem, 7vw, 6.5rem) 0;
}
.experts-boundary > header{
  max-width: 760px;
  margin-bottom: clamp(2.5rem, 5vw, 4rem);
}
.experts-responsibility-matrix{
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  overflow: hidden;
  border: 1px solid var(--card-line);
  border-radius: 8px;
}
.experts-responsibility-matrix article{
  min-height: 0;
  padding: clamp(2rem, 4vw, 3rem);
  background: var(--card-surface);
}
.experts-responsibility-matrix article:last-child{
  border-left: 1px solid var(--card-line);
  background: var(--card-surface);
}
.experts-responsibility-matrix article:last-child > span{
  color: var(--copper);
}
.experts-responsibility-matrix h3{
  max-width: 14ch;
  margin: 1.4rem 0 1.2rem;
  font-size: clamp(1.85rem, 2.6vw, 2.65rem);
  font-weight: 400;
  line-height: 1.08;
}
.experts-responsibility-matrix ul{
  display: grid;
  gap: 0.9rem;
  margin: 0;
  padding-left: 1.2rem;
  color: rgba(24, 21, 18, 0.68);
  line-height: 1.66;
}
@media (max-width: 980px) {.experts-story,
.experts-field{
    grid-template-columns: 1fr;
  }
.experts-credentials{
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
.experts-credentials article:last-child{
    grid-column: 1 / -1;
  }}
.product-experience .official-hero--learning-hub{
  --hero-image: url("assets/heroes/learning/longevity-reading-session.webp");
  --hero-position: center 52%;
}
.hub-selector--learning{
  padding-top: clamp(5rem, 8vw, 7rem);
}
.hub-selector--learning .family-selector__intro{
  margin-bottom: clamp(2.5rem, 5vw, 4rem);
}
.hub-selector--learning .family-row{
  grid-template-columns: repeat(2, minmax(0, 1fr));
  padding: clamp(2.25rem, 4vw, 3.75rem) 0;
}
.hub-selector--learning .family-row__media img{
  aspect-ratio: 16 / 9;
}
.hub-selector--learning .family-row__copy h3{
  font-size: clamp(2.25rem, 4vw, 3.8rem);
}
/* Learning hero overrides stay last so shared product rules cannot replace them. */
.product-experience .official-hero--learning-hub{
  --hero-image: url("assets/heroes/learning/longevity-reading-session.webp");
  --hero-position: center 48%;
}
/* Learning compact type: wrap freely, but keep titles to at most two lines. */
.learning-guide:not(.hub-experience) .product-closing-cta--framed h2{
  margin: 0.55rem 0 0.9rem;
  max-width: 100%;
  color: #000000;
  font-size: clamp(1.7rem, 2.2vw, 2.15rem);
  line-height: 1.08;
  letter-spacing: -0.02em;
  text-align: center;
  white-space: normal;
  overflow-wrap: break-word;
  display: -webkit-box;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 2;
  overflow: hidden;
}
.learning-guide:not(.hub-experience) .product-closing-cta--framed .product-closing-cta__title-line{
  display: inline;
  white-space: normal;
}
.learning-guide:not(.hub-experience) .product-closing-cta--framed p{
  max-width: 38ch;
  margin: 0 auto 1.25rem;
  text-align: center;
}
.learning-guide:not(.hub-experience) .product-closing-cta--framed .page-actions{
  justify-content: center;
}
/*
  Reaffirm Learning compact CTA after the shared photo-frame contract.
  Product pages keep 560px / content-rail; Learning stays a text-led panel.
*/
.learning-guide:not(.hub-experience) .product-closing-cta--framed{
  --cta-frame-min-height: 0;
  --cta-content-padding: clamp(1.75rem, 3vw, 2.5rem);
  --cta-frame-columns: minmax(0, 1fr);
  --cta-frame-radius: clamp(1rem, 1.6vw, 1.35rem);

  grid-template-columns: minmax(0, 1fr);
  gap: 0;
  width: min(48rem, calc(100% - var(--content-rail-inset)));
  max-width: min(48rem, calc(100% - var(--content-rail-inset)));
  min-height: 0;
  height: auto;
  overflow-x: clip;
  overflow-y: visible;
  text-align: center;
}
.learning-guide:not(.hub-experience) .product-closing-cta--framed .product-closing-cta__content{
  min-height: 0;
  height: auto;
  align-items: center;
  justify-content: flex-start;
  padding: var(--cta-content-padding);
  text-align: center;
}
.learning-guide:not(.hub-experience) .product-closing-cta--framed h2{
  margin: 0.55rem 0 0.9rem;
  max-width: 100%;
  font-size: clamp(1.7rem, 2.2vw, 2.15rem);
  line-height: 1.08;
  letter-spacing: -0.02em;
  text-align: center;
  white-space: normal;
  overflow-wrap: break-word;
  display: -webkit-box;
  -webkit-box-orient: vertical;
  -webkit-line-clamp: 2;
  overflow: hidden;
}
.learning-guide:not(.hub-experience) .product-closing-cta--framed .product-closing-cta__title-line{
  display: inline;
  white-space: normal;
}
.learning-guide:not(.hub-experience) .product-closing-cta--framed p{
  max-width: 38ch;
  margin: 0 auto 1.25rem;
  text-align: center;
}
.learning-guide:not(.hub-experience) .product-closing-cta--framed .page-actions{
  justify-content: center;
}
@media (min-width: 961px) {.learning-guide:not(.hub-experience) .product-closing-cta--framed h2{
    white-space: normal;
  }}
.learning-directory__search{
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  gap: 0.9rem;
  align-items: center;
  min-height: 58px;
  padding: 0 1.05rem;
  border: 1px solid rgb(0 0 0 / 24%);
  border-radius: 9px;
  background: rgb(255 255 255 / 36%);
  color: rgb(0 0 0 / 68%);
}
.learning-directory__search img{
  width: 1.35rem;
  height: 1.35rem;
  opacity: 0.82;
}
.learning-directory__search input{
  min-width: 0;
  border: 0;
  outline: 0;
  background: transparent;
  color: var(--ink);
  font: inherit;
}
.learning-directory__search input::placeholder{
  color: rgb(0 0 0 / 42%);
  opacity: 1;
}
.learning-directory__search:focus-within{
  border-color: var(--copper);
  box-shadow: 0 0 0 3px rgb(184 127 69 / 12%);
}
.learning-directory__result small{
  color: var(--copper);
  font-size: 0.68rem;
  font-style: normal;
  font-weight: 700;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}
.learning-directory__empty{
  display: grid;
  gap: 0.35rem;
  min-height: 9rem;
  align-content: center;
  border-top: 1px solid rgb(0 0 0 / 13%);
  color: rgb(0 0 0 / 56%);
}
.learning-directory__empty strong{
  color: var(--ink);
  font-size: 1.08rem;
}
.learning-directory__search{
  grid-template-columns: auto minmax(0, 1fr);
  margin-bottom: 1.2rem;
  background: rgb(255 249 240 / 74%);
}
.learning-directory__results{
  border-bottom: 1px solid rgb(0 0 0 / 14%);
}
.learning-directory__result{
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 1.4rem;
  align-items: center;
  padding: 1.3rem 0.25rem;
  border-top: 1px solid rgb(0 0 0 / 14%);
  color: var(--ink);
  text-decoration: none;
}
.learning-directory__result > span:first-child{
  display: grid;
  gap: 0.32rem;
}
.learning-directory__result strong{
  font-size: clamp(1.15rem, 1.65vw, 1.42rem);
  font-weight: 500;
  line-height: 1.25;
}
.learning-directory__result em{
  color: rgb(0 0 0 / 56%);
  font-size: 0.88rem;
  font-style: normal;
  line-height: 1.48;
}
.learning-directory__result > span:last-child{
  font-size: 1.45rem;
  transition: transform 180ms ease;
}
.learning-directory__result:hover,
.learning-directory__result:focus-visible,
.learning-directory__result.is-selected{
  color: var(--copper);
}
.learning-directory__result:hover > span:last-child,
.learning-directory__result:focus-visible > span:last-child,
.learning-directory__result.is-selected > span:last-child{
  transform: translateX(0.28rem);
}
.learning-directory__result:focus-visible{
  outline: 2px solid var(--copper);
  outline-offset: 4px;
}
@media (prefers-reduced-motion: reduce) {.learning-directory__result > span:last-child{
    transition: none;
  }}
/* Learning hub: preserve the editorial image-led page and add search as a tool. */
.learning-library__search{
  display: grid;
  width: min(860px, 100%);
  margin: clamp(1.8rem, 3vw, 2.5rem) auto 0;
}
.learning-library__search .learning-directory__search{
  grid-template-columns: auto minmax(0, 1fr);
  min-height: 60px;
  background: var(--card-surface);
}
.learning-library__status{
  min-height: 1.4rem;
  margin: 0.7rem 0 0;
  color: var(--ink-soft);
  font-size: 0.78rem;
  letter-spacing: 0.02em;
  text-align: center;
}
.hub-selector--learning .family-selector__intro{
  margin-bottom: clamp(1.75rem, 3vw, 2.75rem);
}
.hub-selector--learning .family-selector__intro > p{
  max-width: 44rem;
  margin-inline: auto;
}
.hub-selector--learning .learning-library__search{
  margin-top: clamp(1.15rem, 2vw, 1.6rem);
}
.learning-library__results{
  display: block;
}
.learning-library__results[hidden],
.learning-library__search-results[hidden]{
  display: none;
}
.learning-library__search-results{
  margin-top: clamp(1.5rem, 3vw, 2.5rem);
}
.learning-library__empty{
  display: grid;
  gap: 0.45rem;
  min-height: 14rem;
  place-content: center;
  border-top: 1px solid rgb(0 0 0 / 14%);
  border-bottom: 1px solid rgb(0 0 0 / 14%);
  color: var(--ink-soft);
  text-align: center;
}
.learning-library__empty[hidden]{
  display: none;
}
.learning-library__empty strong{
  color: var(--ink);
  font-size: clamp(1.4rem, 2vw, 1.8rem);
}
/* Learning editorial articles: evidence-first openings without a forced photo banner. */
.learning-guide--editorial :is(.learning-section, .study-panel, .evidence-key, .comparison-visual, .research-spotlight, .safety-panel){
  padding-top: clamp(3.75rem, 6.5vw, 6rem);
  padding-bottom: clamp(3.75rem, 6.5vw, 6rem);
}
/* Condition pages do not use generic chamber photography as medical evidence. */
/* Editorial articles close with the same compact text-led Learning CTA. */
/* Learning V3 final cascade: every guide begins with the same calm, text-led entry. */
.learning-guide:not(.hub-experience) .official-hero--product{
  min-height: 0 !important;
  padding: clamp(4.25rem, 7vw, 6.25rem) 0 clamp(3rem, 4.75vw, 4.5rem) !important;
  background: radial-gradient(circle at 84% 14%, rgba(184, 108, 43, 0.09), transparent 30%), var(--page-bg) !important;
}
.learning-guide:not(.hub-experience) .official-hero--product .official-hero__media,
.learning-guide:not(.hub-experience) .official-hero--product::after{
  display: none !important;
}
.learning-guide:not(.hub-experience) .official-hero--product .official-hero__inner{
  display: block !important;
  width: min(100% - 3rem, 76rem) !important;
  margin: 0 auto !important;
  padding: 0 !important;
  text-align: center !important;
}
.learning-guide:not(.hub-experience) .official-hero--product .eyebrow,
.learning-guide:not(.hub-experience) .official-hero--product p,
.learning-guide:not(.hub-experience) .official-hero--product .page-actions{
  max-width: min(100%, 43rem) !important;
  margin-right: auto !important;
  margin-left: auto !important;
  text-align: center !important;
}
.learning-guide:not(.hub-experience) .official-hero--product h1{
  /* A centered Learning display title may use the full Hero rail, never a third line. */
  max-width: min(100%, 76rem) !important;
  margin-top: 0.75rem !important;
  margin-bottom: 1.15rem !important;
  font-size: clamp(2.85rem, 5vw, 5rem) !important;
  line-height: 0.96 !important;
  text-wrap: balance !important;
}
.learning-guide:not(.hub-experience) .official-hero--product p{
  margin-bottom: 1.25rem !important;
}
.learning-guide:not(.hub-experience) .official-hero--product .page-actions{
  justify-content: center !important;
}
/* Literature pages read as one article column: heading, then body, same measure. */
.learning-guide--text .learning-intro{
  display: flex;
  flex-direction: column;
  align-items: stretch;
  gap: 1.15rem;
  width: min(100% - 2.5rem, 42rem);
  margin-inline: auto;
  padding: clamp(2.5rem, 4vw, 3.75rem) 0;
}
.learning-guide--text .learning-intro > :first-child{
  max-width: none;
}
.learning-guide--text .learning-intro h2,
.learning-guide--text .learning-section__header h2{
  max-width: none;
  margin: 0.35rem 0 0;
  font-size: clamp(1.4rem, 2vw, 1.75rem);
  line-height: 1.22;
  letter-spacing: -0.025em;
}
.learning-guide--text .learning-intro__copy{
  width: 100%;
  max-width: none;
  column-count: 1;
}
.learning-guide--text .learning-intro__copy p{
  margin-top: 0;
  text-align: justify;
  text-justify: inter-word;
}
/* Keep a section headline and its cards in one visual beat, especially for concise factor lists. */
.learning-guide--text .learning-section{
  padding-block: clamp(2.75rem, 4vw, 4rem);
}
.learning-guide--text .learning-section__header{
  margin-bottom: clamp(1.5rem, 2.5vw, 2.5rem);
}
/* On desktop, a Learning section heading may use its full reading rail.
   Let the viewport, rather than an arbitrary character cap, decide the wrap. */
@media (min-width: 961px) {.learning-guide--text :is(
    .learning-section__header,
    .learning-faq > header,
    .comparison-visual > header
  ){
    max-width: none;
  }
.learning-guide--text :is(
    .learning-intro h2,
    .learning-section__header h2,
    .learning-faq > header h2,
    .evidence-key h2,
    .comparison-visual > header h2,
    .study-panel__copy h2,
    .research-spotlight h2,
    .safety-panel__title h2,
    .learning-boundary h2
  ){
    max-width: none;
    text-wrap: pretty;
  }}
.learning-guide--text .learning-steps article{
  padding: clamp(1.35rem, 2.25vw, 2rem);
}
.learning-guide--text .learning-steps h3{
  margin-top: 1.1rem;
}
/* Text-led guides use evidence and diagrams, not full-bleed product photography.
   This also protects retained legacy article markup while the document cache expires. */
.learning-guide--text .study-panel{
  grid-template-columns: minmax(0, 1fr) !important;
}
.learning-guide--text .study-panel__media{
  display: none !important;
}
/* A safety heading introduces the whole check, then the image and checklist begin together. */
.learning-guide--text .safety-panel--with-media{
  grid-template-columns: minmax(380px, 0.95fr) minmax(0, 1.05fr);
  align-items: start;
}
.learning-guide--text .safety-panel--with-media .safety-panel__intro{
  display: contents;
}
.learning-guide--text .safety-panel--with-media .safety-panel__title{
  grid-column: 1 / -1;
}
.learning-guide--text .safety-panel--with-media .safety-panel__media{
  grid-column: 1;
  margin-top: 0;
}
.learning-guide--text .safety-panel--with-media > ol{
  grid-column: 2;
  margin-top: 0;
}
@media (max-width: 900px) {.learning-guide--text .learning-intro{
    width: min(100% - 2rem, 42rem);
    gap: 1.1rem;
  }
.learning-guide--text .safety-panel--with-media{
    grid-template-columns: 1fr;
  }
.learning-guide--text .safety-panel--with-media .safety-panel__title,
.learning-guide--text .safety-panel--with-media .safety-panel__media,
.learning-guide--text .safety-panel--with-media > ol{
    grid-column: 1;
  }
.learning-guide--text .learning-intro__copy{
    column-count: 1;
  }}
.official-hero__media--learning-reading{
  --hero-image-position: 58% center;
}
/* learning.css: one consolidated <=700px sheet (last-wins cascade flattened). */
@media (max-width: 700px) {.learning-guide:not(.hub-experience) .official-hero--product .official-hero__inner{
    width: min(100% - 2.25rem, 76rem) !important;
    padding: 5.6rem 0 3.5rem;
  }
.learning-guide:not(.hub-experience) .official-hero--product h1{
    max-width: min(100%, 92vw) !important;
    font-size: clamp(2.15rem, 9.2vw, 2.75rem) !important;
    line-height: 1.02 !important;
    text-wrap: unset !important;
  }
.learning-guide:not(.hub-experience) .official-hero--product p{
    max-width: 34ch;
    font-size: 1rem;
  }
.learning-guide:not(.hub-experience) .product-closing-cta--framed{
    width: min(100%, calc(100% - 2rem));
    max-width: min(100%, calc(100% - 2rem));
    min-height: 0;
    overflow: visible;
  }
.learning-guide:not(.hub-experience) .product-closing-cta--framed .product-closing-cta__content{
    padding: 1.45rem 1.15rem 1.65rem;
  }
.learning-guide:not(.hub-experience) .product-closing-cta--framed .page-actions,
.learning-guide:not(.hub-experience) .product-closing-cta--framed .page-actions:has(> :nth-child(2):last-child){
    flex-direction: column;
    flex-wrap: wrap;
    align-items: stretch;
    gap: 0.85rem;
    width: 100%;
  }
.learning-guide:not(.hub-experience) .product-closing-cta--framed .page-actions .button,
.learning-guide:not(.hub-experience) .product-closing-cta--framed .page-actions:has(> :nth-child(2):last-child) .button{
    flex: 0 0 auto;
    width: 100%;
    min-height: 2.75rem;
    padding-inline: 1.1rem;
    font-size: 0.88rem;
    white-space: normal;
    text-align: center;
  }
.learning-guide:not(.hub-experience) .product-closing-cta--framed .page-actions .product-closing-cta__link,
.learning-guide:not(.hub-experience) .product-closing-cta--framed .page-actions:has(> :nth-child(2):last-child) .product-closing-cta__link{
    display: inline-flex;
    flex: 0 0 auto;
    align-items: center;
    justify-content: center;
    width: 100%;
    min-height: 0;
    white-space: normal;
    text-align: center;
    font-size: 0.88rem;
  }
.learning-guide{
    --learning-width: calc(100% - 2rem);
  }
.learning-guide .official-hero--product .official-hero__inner{
    padding-inline: 0;
    width: min(100% - 2rem, 40rem);
    padding: 6.75rem 0 3.25rem;
    text-align: center;
  }
.learning-guide .official-hero--product h1{
    max-width: 12ch;
    font-size: clamp(2.05rem, 8.6vw, 2.5rem);
    margin-top: 0.65rem;
    line-height: 1.03;
    letter-spacing: -0.035em;
    white-space: normal;
  }
.learning-intro h2,
.learning-section__header h2,
.comparison-visual > header h2,
.study-panel__copy h2,
.research-spotlight h2,
.safety-panel__title h2{
    max-width: min(22ch, 100%);
    font-size: clamp(2.05rem, 9.5vw, 2.7rem);
  }
.hub-selector--learning .family-row,
.hub-selector--learning .family-row--reverse{
    grid-template-columns: 1fr;
  }
.hub-selector--learning .family-row--reverse .family-row__media{
    order: 0;
  }
.hub-selector--learning .family-row__copy h3{
    font-size: clamp(2.15rem, 11vw, 3rem);
  }
.learning-claim-matrix,
.comparison-visual__items,
.mechanism-strip,
.learning-flow,
.learning-steps,
.evidence-ladder,
.mechanism-strip--three{
    grid-template-columns: 1fr;
  }
.mechanism-strip article,
.learning-flow article,
.learning-steps article,
.evidence-ladder article{
    border-top: 1px solid rgba(24, 21, 18, 0.12);
    border-left: 0;
  }
.mechanism-strip article:first-child,
.learning-flow article:first-child,
.learning-steps article:first-child,
.evidence-ladder article:first-child{
    border-top: 0;
  }
.learning-section--tint{
    padding-inline: 1rem;
  }
.learning-claim-matrix article + article{
    border-top: 1px solid rgba(24, 21, 18, 0.12);
    border-left: 0;
  }
.research-spotlight__number{
    font-size: 8rem;
  }
.experts-guide{
    --experts-width: calc(100% - 2rem);
  }
.experts-credentials,
.experts-responsibility-matrix{
    grid-template-columns: 1fr;
  }
.experts-person{
    grid-template-columns: 5.5rem minmax(0, 1fr);
  }
.experts-person > img{
    width: 5.5rem;
    height: 5.5rem;
  }
.experts-credentials article:last-child{
    grid-column: auto;
  }
.experts-field{
    padding: 2.25rem 1.5rem;
  }
.experts-story__copy h2,
.experts-field__copy h2,
.experts-boundary h2{
    max-width: 12ch;
    font-size: clamp(2.2rem, 11vw, 3rem);
  }
.experts-responsibility-matrix article:last-child{
    border-top: 1px solid rgba(24, 21, 18, 0.12);
    border-left: 0;
  }
.study-panel,
.comparison-visual{
    scroll-margin-top: 5rem;
  }
.learning-guide .hub-selector--learning .family-row,
.learning-guide .hub-selector--learning .family-row--reverse{
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
    overflow: hidden;
    border: 1px solid rgb(24 21 18 / 10%);
    background: #fff9f0;
  }
.learning-guide .hub-selector--learning .family-row__media,
.learning-guide .hub-selector--learning .family-row--reverse .family-row__media{
    order: 0;
    min-height: 0;
    aspect-ratio: 16 / 9;
  }
.learning-guide .hub-selector--learning .family-row__media img{
    width: 100%;
    height: 100%;
    object-fit: cover;
  }
.learning-guide .hub-selector--learning .family-row__copy{
    order: 1;
    padding: 1.2rem;
  }
.learning-guide .hub-selector--learning .family-row__copy h3{
    max-width: 16ch;
    font-size: clamp(1.7rem, 8vw, 2.2rem);
    line-height: 1;
  }
.learning-guide .hub-selector--learning .family-row__copy p{
    display: block;
    max-width: 35ch;
    margin-bottom: 0.95rem;
    overflow: visible;
    -webkit-box-orient: vertical;
    -webkit-line-clamp: unset;
  }
.learning-directory__search{
    min-height: 54px;
  }
.learning-directory__result{
    padding: 1.2rem 0;
  }
.learning-directory__result em{
    display: none;
  }
.learning-library__search{
    margin-top: 1.5rem;
  }
.learning-library__search .learning-directory__search{
    min-height: 54px;
  }
.learning-library__status{
    text-align: center;
  }
body:has(.learning-guide--editorial) .floating-cta,
  body:has(.learning-guide--essay) .floating-cta{
    opacity: 0;
    pointer-events: none;
    transform: translateY(1rem);
  }
.learning-guide:not(.hub-experience) .official-hero--product{
    padding: 5.5rem 0 2.75rem !important;
  }
.official-hero__media--learning-reading{
    --hero-image-position: 44% center;
  }
}

/* Mini-review literature guides */
.learning-review-copy{
  max-width: 68ch;
}
.learning-review-copy p + p,
.learning-section__header .learning-review-copy p + p{
  margin-top: 1rem;
}
.learning-references{
  list-style: none;
  margin: 1.15rem 0 0;
  padding: 0;
  max-width: 68ch;
}
.learning-references li{
  margin: 0 0 1rem;
  padding-left: 2rem;
  color: var(--ink-soft);
  font-size: 0.95rem;
  line-height: 1.65;
  text-indent: -2rem;
}
.learning-references a{
  overflow-wrap: anywhere;
}
.learning-references--ieee{
  list-style: none;
  padding-left: 0;
  counter-reset: ieee-ref;
}
.learning-references--ieee li{
  padding-left: 2.4rem;
  text-indent: -2.4rem;
  counter-increment: ieee-ref;
}
.learning-references--ieee li::before{
  content: "[" counter(ieee-ref) "] ";
  font-variant-numeric: tabular-nums;
}
.learning-cite{
  margin-left: 0.12em;
  color: var(--copper);
  font-weight: 700;
  text-decoration: none;
}
.learning-cite:hover,
.learning-cite:focus-visible{
  text-decoration: underline;
}
/* English paper reader. All selectors are scoped to the opt-in reader. */
.learning-essay.is-paper-book{
  display: block;
  isolation: isolate;
  overflow: hidden;
  height: clamp(32rem, 76svh, 54rem);
  min-height: 0;
  padding: 0;
  touch-action: pan-y;
  user-select: none;
}
.is-paper-book .learning-paper{
  position: absolute;
  inset: 0 auto 0 0;
  width: 50%;
  box-sizing: border-box;
  padding: 0;
  background: var(--card-surface);
  overflow: hidden;
}
.is-paper-book .learning-paper[data-side="right"]{ left: 50%; }
.is-paper-book .learning-paper[hidden]{ display: none; }
/* Every paper face carries its gutter lighting, including fold clones. */
.is-paper-book .learning-paper::after{
  content: "";
  position: absolute;
  inset: 0 0 0 auto;
  width: 14px;
  background: linear-gradient(90deg, transparent, rgba(51, 35, 18, .065));
  pointer-events: none;
}
.is-paper-book .learning-paper[data-side="right"]::after{
  inset: 0 auto 0 0;
  background: linear-gradient(90deg, rgba(51, 35, 18, .065), transparent);
}
.learning-essay.is-paper-book .learning-paper > section{
  box-sizing: border-box;
  display: block;
  height: 100%;
  min-height: 0;
  max-height: none;
  width: 100%;
  margin: 0;
  padding: clamp(2rem, 3vw, 3rem) clamp(1.5rem, 3vw, 2.8rem);
  border: 0;
  overflow: auto;
  touch-action: pan-y;
  overscroll-behavior-y: auto;
  scrollbar-width: thin;
  scrollbar-color: rgba(115, 84, 48, .22) transparent;
}
.is-paper-book.is-turning-paper{ user-select: none; }
.is-paper-book:focus-visible{ outline: 2px solid var(--copper); outline-offset: 3px; }
.learning-paper-turn,
.learning-paper-turn__under,
.learning-paper-turn__front,
.learning-paper-turn__back,
.learning-paper-turn__back-content{
  position: absolute;
  inset: 0;
  transform-origin: 0 0;
  pointer-events: none;
}
.learning-paper-turn{ z-index: 5; }
.learning-paper-turn[hidden]{ display: none; }
.learning-paper-turn__front,
.learning-paper-turn__back{ will-change: clip-path; }
.learning-paper-turn__back{
  background: var(--card-surface);
}
.learning-paper-turn__back-content{ will-change: transform; }
.learning-paper-turn__shadow{
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  overflow: visible;
  fill: #392919;
}
.learning-paper-turn__crease{
  position: absolute;
  background: linear-gradient(90deg, transparent, rgba(105, 76, 40, .07) 23%, rgba(83, 56, 25, .2) 49%, rgba(255, 255, 255, .64) 67%, transparent);
}
.learning-paper-controls{
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: var(--essay-width);
  box-sizing: border-box;
  margin: 0 auto;
  padding: 1rem 1.35rem;
  gap: 1.5rem;
  border: 1px solid var(--card-line);
  border-bottom: 0;
  background: var(--card-surface);
  color: var(--ink-soft);
  font-size: .82rem;
}
.learning-paper-controls.is-quiet{ opacity: 1; }
.learning-paper-controls.is-quiet:hover,
.learning-paper-controls.is-quiet:focus-within{ opacity: 1; }
.learning-paper-controls > div{ display: flex; align-items: center; gap: .8rem; }
.learning-paper-controls .learning-paper-controls__guide{ align-items: flex-start; flex-direction: column; gap: .2rem; }
.learning-paper-controls__guide strong{ color: var(--ink); font-weight: 600; font-size: .95rem; }
.learning-paper-controls__actions{ flex-shrink: 0; }
.learning-paper-controls__count{ min-width: 4rem; text-align: center; font-variant-numeric: tabular-nums; }
.learning-paper-controls button{
  min-width: 110px;
  height: 44px;
  padding: 0 .9rem;
  border: 1px solid var(--card-line);
  border-radius: 5px;
  background: transparent;
  color: var(--ink);
  font: inherit;
  white-space: nowrap;
  cursor: pointer;
  transition: background .18s, transform .18s;
}
.learning-paper-controls button:hover:not(:disabled){ background: var(--card-surface); }
.learning-paper-controls button:last-child:not(:disabled){ color: var(--copper); border-color: var(--copper); }
.learning-paper-controls button:active:not(:disabled){ transform: scale(.94); }
.learning-paper-controls button:focus-visible{ outline: 2px solid var(--copper); outline-offset: 3px; }
.learning-paper-controls button:disabled{ opacity: .3; cursor: default; }
.learning-essay.is-paper-book--single{ height: clamp(29rem, 70svh, 44rem); }
.is-paper-book--single .learning-paper{ width: 100%; }
.is-paper-book--single .learning-paper > section{ padding: 1.65rem 1.4rem; }
.is-paper-book--single .learning-paper::after{ display: none; }
@media (max-width: 600px){
  .learning-paper-controls{ align-items: stretch; flex-direction: column; gap: .85rem; padding: .9rem 1rem; font-size: .76rem; }
  .learning-paper-controls .learning-paper-controls__actions{ justify-content: space-between; gap: .25rem; }
  .learning-paper-controls button{ min-width: 0; padding: 0 .7rem; }
  .is-paper-book--single .learning-paper p{ font-size: .98rem; line-height: 1.65; }
}
@media (max-width: 700px){
  .learning-paper-controls{
    position: relative;
    display: block;
    margin: 0 auto;
    padding: .78rem 1.1rem .9rem;
    border: 0;
    border-bottom: 1px solid var(--card-line);
    background: transparent;
    text-align: center;
  }
  .learning-paper-controls .learning-paper-controls__guide{
    align-items: center;
    gap: .12rem;
  }
  .learning-paper-controls__guide strong{
    font-size: 0;
    letter-spacing: .08em;
    text-transform: uppercase;
  }
  .learning-paper-controls__guide strong::after{
    content: "Swipe to turn";
    font-size: .72rem;
  }
  html[lang^="zh"] .learning-paper-controls__guide strong::after{ content: "左右滑动翻页"; }
  .learning-paper-controls__hint{ color: rgba(24, 21, 18, .58); font-size: .76rem; }
  .learning-paper-controls .learning-paper-controls__actions{
    justify-content: center;
    gap: .72rem;
    margin-top: .35rem;
  }
  .learning-paper-controls .learning-paper-controls__actions button{
    display: inline-grid;
    width: 2.4rem;
    min-width: 2.4rem;
    height: 2.1rem;
    place-items: center;
    padding: 0;
    border: 0;
    color: var(--copper);
    font-size: 0;
    line-height: 1;
  }
  .learning-paper-controls .learning-paper-controls__actions button .learning-paper-controls__button-label{
    display: none;
  }
  .learning-paper-controls .learning-paper-controls__actions button .learning-paper-controls__button-arrow{
    font-size: 1.08rem;
    line-height: 1;
  }
  .learning-paper-controls .learning-paper-controls__actions button:hover:not(:disabled),
  .learning-paper-controls .learning-paper-controls__actions button:last-child:not(:disabled){
    border-color: transparent;
    background: transparent;
    color: var(--copper);
  }
  .learning-paper-controls .learning-paper-controls__actions button:not(:disabled):active{ transform: scale(.9); }
  .learning-paper-controls .learning-paper-controls__actions button:disabled{ visibility: hidden; }
  .learning-paper-controls__count{ min-width: 0; color: var(--copper); font-size: .78rem; }
}
@keyframes learning-mobile-corner{
  0%, 64%, 100%{ transform: translate3d(0, 0, 0) rotate(0deg) scale3d(1, 1, 1); }
  13%{ transform: translate3d(-.3px, -.3px, 0) rotate(-.12deg) scale3d(1.004, 1.004, 1); }
  29%{ transform: translate3d(-1.7px, -1.7px, 0) rotate(-.85deg) scale3d(1.028, 1.028, 1); }
  43%{ transform: translate3d(-.4px, -.4px, 0) rotate(-.18deg) scale3d(1.006, 1.006, 1); }
}
@keyframes learning-swipe-cue{
  from{ transform: translateX(0); opacity: .38; }
  to{ transform: translateX(4px); opacity: .95; }
}
@media (prefers-reduced-motion: reduce){
  .learning-paper-controls,
  .learning-paper-controls button{ transition: none; }
  .learning-paper-nudge{ display: none; }
  .is-paper-book--single.is-paper-book--can-next > .learning-paper::before{ animation: none; }
}

/* Literature essays read as an open book on the shared Learning rail. */
.learning-guide--essay{
  --essay-width: min(100% - 2.5rem, var(--learning-rail-width));
  --essay-gutter: clamp(2.5rem, 4vw, 4.75rem);
}
.learning-guide--essay .official-hero--product .official-hero__inner{
  width: var(--essay-width) !important;
}
.learning-guide--essay .official-hero--product h1{
  max-width: 12ch !important;
  font-size: clamp(2.75rem, 5vw, 4.4rem) !important;
  letter-spacing: -0.04em !important;
}
.learning-guide--essay .official-hero--product p{
  max-width: min(42rem, 100%) !important;
}
.learning-essay__nav{
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  width: var(--essay-width);
  margin: 0 auto;
  padding: 1.05rem 1.35rem 1.15rem;
  border: 1px solid var(--card-line);
  border-bottom: 0;
  border-radius: 8px 8px 0 0;
  background: var(--card-surface);
}
.learning-essay__nav a{
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  min-width: 0;
  padding: 0.15rem 0.4rem 0.15rem 0;
  color: var(--ink);
  font-size: 0.78rem;
  line-height: 1.25;
  text-decoration: none;
}
.learning-essay__nav a + a{
  border-left: 1px solid rgba(24, 21, 18, 0.12);
  padding-left: 0.85rem;
}
.learning-essay__nav a.is-current,
.learning-essay__nav a[aria-current="location"]{
  color: var(--copper);
}
.learning-essay__nav > a > span:first-child{
  color: var(--ink-soft);
  font-family: var(--font-glacial);
  font-size: 0.68rem;
  font-weight: 800;
  letter-spacing: 0.12em;
}
.learning-essay__nav a.is-current > span:first-child,
.learning-essay__nav a[aria-current="location"] > span:first-child{ color: var(--copper); }
.learning-essay{
  position: relative;
  width: var(--essay-width);
  margin: 0 auto;
  padding: clamp(2.25rem, 4vw, 3.25rem) 1.5rem clamp(3rem, 5vw, 4.5rem);
  border: 1px solid var(--card-line);
  border-radius: 0 0 8px 8px;
  background: var(--card-surface);
}
.learning-essay__spread{
  display: contents;
}
.learning-essay section + section{
  margin-top: clamp(2.25rem, 3.5vw, 3rem);
  padding-top: clamp(2.25rem, 3.5vw, 3rem);
  border-top: 1px solid rgba(24, 21, 18, 0.12);
}
.learning-essay h2{
  max-width: none;
  margin: 0 0 1rem;
  font-size: clamp(1.35rem, 2vw, 1.65rem);
  font-weight: 500;
  line-height: 1.28;
  letter-spacing: -0.03em;
}
.learning-essay p{
  margin: 0 0 1rem;
  color: rgba(24, 21, 18, 0.72);
  font-size: 1.05rem;
  line-height: 1.72;
}
.learning-essay .label{
  display: block;
  margin-bottom: 0.45rem;
}
.learning-guide--essay :is(.learning-intro, .learning-section, .research-spotlight, .learning-section--tint){
  display: block;
  width: auto;
  max-width: none;
  margin: 0;
  padding: 0;
  border: 0;
  background: transparent;
  grid-template-columns: none;
  gap: 0;
}
.learning-guide--essay .learning-intro > :first-child,
.learning-guide--essay .learning-section__header,
.learning-guide--essay .research-spotlight__copy{
  max-width: none;
  margin: 0 0 1rem;
}
.learning-guide--essay :is(.learning-intro h2, .learning-section__header h2, .research-spotlight h2){
  max-width: none;
  margin: 0 0 1rem;
  font-size: clamp(1.35rem, 2vw, 1.65rem);
  font-weight: 500;
  line-height: 1.28;
  letter-spacing: -0.03em;
}
.learning-guide--essay .research-spotlight__number{
  display: none;
}
.learning-guide--essay .learning-claim-matrix{
  grid-template-columns: 1fr;
  margin: 1.25rem 0;
}
.learning-guide--essay .learning-claim-matrix article + article{
  border-left: 0;
  border-top: 1px solid var(--card-line);
}
.learning-guide--essay .learning-claim-matrix h3{
  max-width: none;
  font-size: 1.2rem;
}
.learning-guide--essay :is(.learning-steps, .learning-findings, .learning-evidence-brief){
  width: 100%;
  margin-top: 1.25rem;
}
.learning-essay__facts{
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  margin: 1.5rem 0;
  overflow: hidden;
  border: 1px solid var(--card-line);
  border-radius: 6px;
  background: var(--card-surface);
}
.learning-essay__facts div{
  padding: 1rem 0.7rem 1.05rem;
  text-align: center;
}
.learning-essay__facts div + div{
  border-left: 1px solid var(--card-line);
}
.learning-essay__facts strong{
  display: block;
  font-size: 1.35rem;
  font-weight: 500;
  letter-spacing: -0.03em;
  line-height: 1.1;
}
.learning-essay__facts span{
  display: block;
  margin-top: 0.4rem;
  color: var(--ink-soft);
  font-size: 0.68rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
.learning-guide--essay .learning-disclaimer{
  width: var(--essay-width);
  margin-inline: auto;
  margin-top: 1.25rem;
}
.js .learning-essay.reveal,
.js .learning-essay .reveal{
  opacity: 1;
  transform: none;
}
.learning-guide--essay .learning-references{
  margin-top: 1.15rem;
}
.learning-essay__leaf{
  display: none;
}
@media (min-width: 961px) {
  .learning-essay{
    --essay-page-pad-top: 2.75rem;
    --essay-page-pad-x: clamp(2rem, 3vw, 3.25rem);
    --essay-page-pad-bottom: 3.4rem;
    display: grid;
    grid-template-columns: 1fr 1fr;
    column-gap: var(--essay-gutter);
    row-gap: 0;
    padding: var(--essay-page-pad-top) var(--essay-page-pad-x) var(--essay-page-pad-bottom);
    background-image:
      linear-gradient(
        90deg,
        transparent calc(50% - 1px),
        rgba(24, 21, 18, 0.08) 50%,
        transparent calc(50% + 1px)
      );
    background-color: var(--card-surface);
    box-shadow: 0 28px 70px rgba(45, 33, 22, 0.08);
  }
  .learning-essay section{
    min-width: 0;
  }
  .learning-essay section + section{
    margin-top: 0;
    padding-top: 0;
    border-top: 0;
  }
  .learning-essay section:nth-child(n + 3){
    margin-top: clamp(2rem, 3vw, 2.75rem);
    padding-top: clamp(2rem, 3vw, 2.75rem);
    border-top: 1px solid rgba(24, 21, 18, 0.12);
  }
  .learning-essay #references{
    grid-column: 1 / -1;
  }
  .learning-essay.is-hinged #references{
    grid-column: auto;
  }
  .learning-essay__leaf{
    display: block;
    position: absolute;
    top: 0;
    bottom: 0;
    z-index: 2;
    width: 2.85rem;
    padding: 0;
    border: 0;
    background: transparent;
    cursor: pointer;
  }
  .learning-essay__leaf--prev{
    left: 0;
    cursor: w-resize;
  }
  .learning-essay__leaf--next{
    right: 0;
    cursor: e-resize;
  }
  .learning-essay__leaf:disabled{
    cursor: default;
  }
  .learning-essay__leaf:focus-visible{
    outline: 2px solid var(--copper);
    outline-offset: -2px;
  }
  .learning-essay.is-hinged{
    display: block;
    overflow: hidden;
    clip-path: inset(0);
    isolation: isolate;
    padding: 0;
    min-height: calc(78vh - 2rem);
    height: calc(78vh - 2rem);
    cursor: grab;
    overscroll-behavior: contain;
    touch-action: pan-y;
  }
  .learning-essay.is-hinged.is-flipping{
    cursor: grabbing;
  }
  .learning-essay.is-hinged .learning-essay__spread{
    display: grid;
    grid-template-columns: 1fr 1fr;
    column-gap: var(--essay-gutter);
    align-items: stretch;
    box-sizing: border-box;
    height: 100%;
    min-height: 100%;
    padding: var(--essay-page-pad-top) var(--essay-page-pad-x) var(--essay-page-pad-bottom);
  }
  .learning-essay.is-hinged .learning-essay__blank{
    min-height: 0;
    background: transparent;
    pointer-events: none;
  }
  .learning-essay.is-hinged .learning-essay__spread.is-off{
    display: none;
  }
  .learning-essay.is-hinged .learning-essay__spread.is-current,
  .learning-essay.is-hinged .learning-essay__spread.is-under{
    position: absolute;
    inset: 0;
    height: auto;
    min-height: 0;
    background-color: var(--card-surface);
    background-image:
      linear-gradient(
        90deg,
        transparent calc(50% - 14px),
        rgba(45, 33, 22, 0.05) 50%,
        transparent calc(50% + 14px)
      );
  }
  .learning-essay.is-hinged .learning-essay__spread.is-current::after,
  .learning-essay.is-hinged .learning-essay__spread.is-under::after{
    content: "";
    position: absolute;
    top: 1.7rem;
    bottom: 1.7rem;
    left: 50%;
    width: 1px;
    margin-left: -0.5px;
    background: linear-gradient(
      180deg,
      transparent,
      rgba(45, 33, 22, 0.16) 10%,
      rgba(45, 33, 22, 0.22) 50%,
      rgba(45, 33, 22, 0.16) 90%,
      transparent
    );
    box-shadow: 1px 0 0 rgba(255, 252, 246, 0.55);
    pointer-events: none;
    z-index: 3;
  }
  .learning-essay.is-hinged .learning-essay__spread.is-under{
    display: grid;
    z-index: 0;
    isolation: isolate;
    pointer-events: none;
    opacity: 1;
  }
  .learning-essay.is-hinged .learning-essay__spread.is-current{
    z-index: 1;
  }
  .learning-essay.is-hinged .learning-essay__spread.is-current section,
  .learning-essay.is-hinged .learning-essay__spread.is-under section{
    min-height: 0;
    max-height: none;
    overflow-x: hidden;
    overflow-y: auto;
    overscroll-behavior: contain;
    background: var(--card-surface);
  }
  .learning-essay.is-hinged section + section,
  .learning-essay.is-hinged section:nth-child(n + 3){
    margin-top: 0;
    padding-top: 0;
    border-top: 0;
  }
  .learning-essay.is-hinged .learning-essay__leaf{
    z-index: 9;
  }
  .learning-essay.is-hinged.is-flipping .learning-essay__leaf{
    pointer-events: none;
  }
  .learning-essay.is-hinged.is-flipping .learning-essay__spread.is-current,
  .learning-essay.is-hinged.is-flipping .learning-essay__hinge-flap{
    will-change: clip-path;
  }
  .learning-essay__hinge{
    position: absolute;
    inset: 0;
    z-index: 4;
    pointer-events: none;
  }
  .learning-essay__hinge-roll{
    position: absolute;
    inset: 0;
    z-index: 5;
    display: block;
    width: 100%;
    height: 100%;
    pointer-events: none;
  }
  .learning-essay__hinge-rest,
  .learning-essay__hinge-flap{
    position: absolute;
    overflow: hidden;
    background: var(--card-surface);
  }
  .learning-essay__hinge-rest{
    z-index: 1;
  }
  .learning-essay__hinge-flap{
    --fold-shade: 0;
    --fold-dir: 1;
    inset: 0;
    z-index: 2;
    overflow: hidden;
    isolation: isolate;
    opacity: 1;
    mix-blend-mode: normal;
    background: var(--card-surface);
  }
  .learning-essay__hinge-paper{
    position: absolute;
    inset: 0;
    z-index: 0;
    background: var(--card-surface);
  }
  .learning-essay__hinge-flap-inner{
    display: none;
  }
  .learning-essay__hinge-copy{
    box-sizing: border-box;
    min-height: 100%;
    max-width: none;
    overflow: hidden;
    color: inherit;
    opacity: 1;
    background: var(--card-surface);
  }
  .learning-essay__hinge-copy > section{
    width: 100%;
    max-width: 100%;
    min-height: 0;
    max-height: none;
    overflow: hidden;
    color: inherit;
    opacity: 1;
    background: var(--card-surface);
  }
  .learning-essay__hinge-face--back{
    position: absolute;
    inset: 0;
    z-index: 1;
    overflow: hidden;
    isolation: isolate;
    pointer-events: none;
    background: var(--card-surface);
  }
  .learning-essay__hinge-curl{
    display: none;
  }
}
@media (max-width: 960px) {
  .learning-essay__nav,
  .learning-essay{
    border-radius: 0;
    background: transparent;
    box-shadow: none;
  }
  .learning-essay__nav{
    padding-inline: 0;
    border-left: 0;
    border-right: 0;
    border-top: 1px solid rgba(24, 21, 18, 0.12);
  }
  .learning-essay{
    padding-inline: 0;
    border-left: 0;
    border-right: 0;
  }
  .learning-guide:not(.hub-experience) [data-product-closing-scroll].is-scroll-motion-ready{
    clip-path: inset(
      calc((1 - var(--product-end-progress, 0)) * 6%)
      calc((1 - var(--product-end-progress, 0)) * 4%)
      calc((1 - var(--product-end-progress, 0)) * 6%)
      calc((1 - var(--product-end-progress, 0)) * 4%)
      round 12px
    );
  }
}
@media (max-width: 700px) {
  .learning-guide--essay{
    --essay-width: min(100% - 2rem, var(--learning-rail-width));
  }
  /* Keep the mobile reader introduction deliberate, without a second empty Hero frame. */
  html[lang^="en"] .learning-guide--essay .official-hero--product{
    min-height: 0 !important;
    padding: 1.5rem 0 .75rem !important;
  }
  html[lang^="en"] .learning-guide--essay .official-hero--product .official-hero__inner{
    padding: 2rem 0 1.25rem !important;
  }
  html[lang^="en"] .learning-essay__nav,
  html[lang^="zh"] .learning-essay__nav{
    display: flex;
    align-items: center;
    width: 100%;
    gap: 1.5rem;
    overflow-x: auto;
    padding: .82rem 1.15rem;
    border: 0;
    border-top: 1px solid rgba(24, 21, 18, .12);
    border-bottom: 1px solid rgba(24, 21, 18, .12);
    border-radius: 0;
    background: transparent;
    scrollbar-width: none;
    -webkit-overflow-scrolling: touch;
    scroll-snap-type: none;
    mask-image: linear-gradient(90deg, #000 0, #000 calc(100% - 1.6rem), transparent);
    -webkit-mask-image: linear-gradient(90deg, #000 0, #000 calc(100% - 1.6rem), transparent);
  }
  html[lang^="en"] .learning-essay__nav::-webkit-scrollbar,
  html[lang^="zh"] .learning-essay__nav::-webkit-scrollbar{ display: none; }
  html[lang^="en"] .learning-essay__nav::before,
  html[lang^="zh"] .learning-essay__nav::before{
    display: none;
  }
  .learning-essay__nav a + a{
    border-left: 0;
    padding-left: 0;
  }
  html[lang^="en"] .learning-essay__nav a:nth-child(2n),
  html[lang^="zh"] .learning-essay__nav a:nth-child(2n){
    border-left: 0;
    padding-left: 0;
  }
  html[lang^="en"] .learning-essay__nav a,
  html[lang^="zh"] .learning-essay__nav a{
    display: flex;
    flex: 0 0 auto;
    align-items: center;
    min-height: 0;
    padding: .15rem 0;
    border-bottom: 0;
    scroll-snap-align: none;
  }
  html[lang^="en"] .learning-essay__nav a + a,
  html[lang^="zh"] .learning-essay__nav a + a{
    border-left: 0;
  }
  html[lang^="en"] .learning-essay__nav a > span:first-child,
  html[lang^="zh"] .learning-essay__nav a > span:first-child{ display: none; }
  html[lang^="en"] .learning-essay__nav a .learning-essay__nav-title,
  html[lang^="zh"] .learning-essay__nav a .learning-essay__nav-title{
    color: inherit;
    font-family: inherit;
    font-size: .78rem;
    font-weight: 400;
    letter-spacing: 0;
    line-height: 1.2;
    white-space: nowrap;
    text-transform: none;
  }
  html[lang^="en"] .learning-essay__nav a:last-child,
  html[lang^="zh"] .learning-essay__nav a:last-child{
    grid-column: auto;
  }
  html[lang^="en"] .learning-paper-controls{
    margin: .1rem auto .6rem;
    padding: .45rem 0 .85rem;
    border: 0;
    border-bottom: 1px solid rgba(24, 21, 18, .12);
    border-radius: 0;
    background: transparent;
  }
  html[lang^="en"] .learning-paper-controls__hint{ max-width: 20rem; }
  /* The folded underside and its cast shadow share one corner coordinate system. */
  html[lang^="en"] .is-paper-book--single.is-paper-book--can-next > .learning-paper::before{
    content: "";
    position: absolute;
    inset: auto -1px -1px auto;
    z-index: 5;
    width: 3.25rem;
    height: 3.25rem;
    box-sizing: border-box;
    background: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 64 64'%3E%3Cdefs%3E%3ClinearGradient id='paper' x1='0' y1='0' x2='1' y2='1'%3E%3Cstop stop-color='%23fffdf8'/%3E%3Cstop offset='.64' stop-color='%23f5eee2'/%3E%3Cstop offset='1' stop-color='%23d8cbb7'/%3E%3C/linearGradient%3E%3Cfilter id='shadow' x='-50%25' y='-50%25' width='200%25' height='200%25'%3E%3CfeGaussianBlur stdDeviation='2'/%3E%3C/filter%3E%3C/defs%3E%3Cpath d='M64 0L0 64H64Z' fill='%23efe7da'/%3E%3Cpath d='M64 0Q40 16 15 14Q15 40 0 64Z' fill='%23675035' opacity='.18' filter='url(%23shadow)' transform='translate(2 3)'/%3E%3Cpath d='M64 0Q37 13 11 11Q13 37 0 64Z' fill='url(%23paper)'/%3E%3Cpath d='M64 0Q37 13 11 11Q13 37 0 64' fill='none' stroke='%23fffdf8' stroke-width='.8'/%3E%3C/svg%3E") center / 100% 100% no-repeat;
    transform-origin: 100% 100%;
    backface-visibility: hidden;
    will-change: transform;
    animation: learning-mobile-corner 6.4s cubic-bezier(.4, 0, .2, 1) infinite;
    pointer-events: none;
  }
  html[lang^="en"] .is-paper-book--single.is-paper-book--can-next > .learning-paper::after{
    content: none;
    display: none;
  }
  html[lang^="en"] .is-paper-book--single.is-turning-paper > .learning-paper::before{ visibility: hidden; }
  html[lang^="en"] .is-paper-book--single > .learning-paper:hover::before{ animation-play-state: paused; }
  /* Mobile reading uses the document's one natural vertical scroll axis. */
  html[lang^="en"] .learning-essay.is-paper-book--single{
    height: auto;
    overflow: visible;
  }
  html[lang^="en"] .learning-essay.is-paper-book--single > .learning-paper{
    position: relative;
    inset: auto;
    width: 100%;
    height: auto;
    overflow: visible;
  }
  html[lang^="en"] .learning-essay.is-paper-book--single > .learning-paper > section{
    height: auto;
    max-height: none;
    overflow: visible;
    overscroll-behavior-y: auto;
    padding-bottom: 2.25rem;
  }
  .learning-essay__facts{
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .learning-essay__facts div:nth-child(2n){
    border-left: 1px solid var(--card-line);
  }
  .learning-essay__facts div:nth-child(n + 3){
    border-top: 1px solid var(--card-line);
  }
}

.learning-health-links{
  margin: clamp(1.5rem, 3vw, 2.5rem) 0 clamp(3rem, 6vw, 5rem);
  padding: clamp(1.5rem, 3vw, 2.5rem);
  border: 1px solid rgb(24 21 18 / 12%);
  border-radius: 1.25rem;
  background: rgb(255 250 242 / 58%);
  scroll-margin-top: 7rem;
}
.learning-health-links__head{ max-width: 44rem; }
.learning-health-links__head h3{
  margin: .5rem 0 .65rem;
  font-size: clamp(1.8rem, 3vw, 2.75rem);
  line-height: 1.04;
}
.learning-health-links__head p{
  margin: 0;
  color: var(--ink-soft);
  line-height: 1.6;
}
.learning-health-links__grid{
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  margin-top: clamp(1.3rem, 3vw, 2rem);
  border-top: 1px solid rgb(24 21 18 / 12%);
}
.learning-health-links__grid a{
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) auto;
  align-items: center;
  gap: .75rem;
  padding: 1rem 0;
  border-bottom: 1px solid rgb(24 21 18 / 12%);
  color: var(--ink);
  text-decoration: none;
}
.learning-health-links__grid a:nth-child(odd){
  padding-right: 1.5rem;
  border-right: 1px solid rgb(24 21 18 / 12%);
}
.learning-health-links__grid a:nth-child(even){ padding-left: 1.5rem; }
.learning-health-links__grid span{
  color: var(--copper);
  font-size: .72rem;
  font-weight: 700;
  letter-spacing: .1em;
}
.learning-health-links__grid b{
  color: var(--copper);
  font-weight: 400;
  transition: transform .2s ease;
}
.learning-health-links__grid a:hover b,
.learning-health-links__grid a:focus-visible b{ transform: translateX(.25rem); }
@media (max-width: 700px){
  .learning-health-links{ scroll-margin-top: 5rem; }
  .learning-health-links__grid{ grid-template-columns: 1fr; }
  .learning-health-links__grid a:nth-child(odd),
  .learning-health-links__grid a:nth-child(even){
    padding-right: 0;
    padding-left: 0;
    border-right: 0;
  }
}

/* Learning hub: four clear topic sections, while retaining the editorial image-led reading rows. */
.learning-topic-section{
  display: grid;
  gap: clamp(1.25rem, 2.25vw, 2rem);
  margin-top: clamp(3.5rem, 8vw, 7rem);
  scroll-margin-top: 7rem;
}
.learning-topic-section:first-child{ margin-top: clamp(2.5rem, 5vw, 4rem); }
.learning-topic-section[hidden]{ display: none; }
.learning-topic-section__header{
  display: flex;
  align-items: baseline;
  gap: .7rem;
  padding-top: .9rem;
  border-top: 1px solid rgb(24 21 18 / 14%);
}
.learning-topic-section__header .label{ flex: 0 0 auto; }
.learning-topic-section__header h3{
  margin: 0;
  font-family: inherit;
  font-size: .95rem;
  font-weight: 500;
  line-height: 1.2;
  letter-spacing: 0;
}
@media (max-width: 700px){
  .learning-topic-section{
    gap: 1.25rem;
    margin-top: 3.25rem;
    scroll-margin-top: 5rem;
  }
  .learning-topic-section__header{
    gap: .55rem;
    padding-top: .8rem;
  }
  .learning-topic-section__header h3{
    margin: 0;
    font-size: .92rem;
  }
}

/* The hub starts with four equal category controls. The editorial rows remain the filtered reading results. */
.learning-category-grid{
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(1.5rem, 3vw, 2.5rem) 0 clamp(2.5rem, 5vw, 4.5rem);
  overflow: hidden;
  border: 1px solid rgb(24 21 18 / 12%);
  border-radius: clamp(1rem, 1.8vw, 1.5rem);
  background: rgb(24 21 18 / 12%);
}
.learning-category-card{
  position: relative;
  display: grid;
  min-height: 14.25rem;
  align-content: start;
  gap: .75rem;
  padding: clamp(1.15rem, 2vw, 1.65rem);
  border: 0;
  background: #fffaf2;
  color: var(--ink);
  cursor: pointer;
  font: inherit;
  text-align: left;
  transition: background .2s ease, color .2s ease;
}
.learning-category-card .label{ color: var(--copper); }
.learning-category-card strong{
  max-width: 13ch;
  font-size: clamp(1.35rem, 1.8vw, 1.75rem);
  font-weight: 500;
  line-height: 1.05;
  letter-spacing: -.035em;
}
.learning-category-card > span:not(.label){
  color: var(--ink-soft);
  font-size: .88rem;
  line-height: 1.5;
}
.learning-category-card b{
  position: absolute;
  right: clamp(1.15rem, 2vw, 1.65rem);
  bottom: 1.2rem;
  color: var(--copper);
  font-size: 1.1rem;
  font-weight: 400;
  transition: transform .2s ease;
}
.learning-category-card:hover,
.learning-category-card:focus-visible,
.learning-category-card[aria-pressed="true"]{
  background: var(--copper);
  color: #fffaf2;
}
.learning-category-card:hover .label,
.learning-category-card:focus-visible .label,
.learning-category-card[aria-pressed="true"] .label,
.learning-category-card:hover > span:not(.label),
.learning-category-card:focus-visible > span:not(.label),
.learning-category-card[aria-pressed="true"] > span:not(.label),
.learning-category-card:hover b,
.learning-category-card:focus-visible b,
.learning-category-card[aria-pressed="true"] b{ color: inherit; }
.learning-category-card:hover b,
.learning-category-card:focus-visible b{ transform: translateX(.25rem); }
.hub-selector--learning .learning-topic-section{
  display: contents;
}
.hub-selector--learning .learning-topic-section[hidden]{ display: none; }
.hub-selector--learning .learning-topic-section__header{ display: none; }
.hub-selector--learning .learning-library__results{
  scroll-margin-top: 7rem;
}
@media (max-width: 900px){
  .learning-category-grid{ grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 700px){
  .learning-category-grid{
    grid-template-columns: 1fr;
    margin-top: 1.35rem;
    margin-bottom: 2.5rem;
  }
  .learning-category-card{ min-height: 10.25rem; }
  .hub-selector--learning .learning-library__results{ scroll-margin-top: 5rem; }
}

/* Text-led Learning guides use a research-reading layout: one clear article entry,
   a generous reading rail, and structured information blocks rather than a literal book effect. */
@media (min-width: 901px){
  .learning-guide--text .official-hero--product .official-hero__inner{
    width: var(--learning-width) !important;
    text-align: left !important;
  }
  .learning-guide--text .official-hero--product :is(.eyebrow, p, .page-actions){
    margin-left: 0 !important;
    margin-right: 0 !important;
    text-align: left !important;
  }
  .learning-guide--text .official-hero--product h1{
    max-width: 18ch !important;
    text-wrap: pretty !important;
  }
  .learning-guide--text .official-hero--product .page-actions{
    justify-content: flex-start !important;
  }
  .learning-guide--text .learning-intro{
    display: grid;
    grid-template-columns: minmax(0, .9fr) minmax(32rem, 1.1fr);
    align-items: start;
    gap: clamp(3rem, 8vw, 9rem);
    width: var(--learning-width);
    max-width: none;
    padding: clamp(4rem, 6vw, 5.75rem) 0;
  }
  .learning-guide--text .learning-intro__copy{
    max-width: 64ch;
  }
  .learning-guide--text .learning-intro h2{
    max-width: 17ch;
    font-size: clamp(2rem, 2.8vw, 3rem);
    line-height: 1.06;
  }
  .learning-guide--text .learning-flow{
    margin-bottom: clamp(2.75rem, 4vw, 4rem);
  }
  .learning-guide--text .study-panel{
    width: var(--learning-width);
    max-width: none;
    padding: clamp(3.5rem, 5vw, 5rem) 0;
  }
  .learning-guide--text .study-panel__copy{
    display: grid;
    grid-template-columns: minmax(0, .85fr) minmax(24rem, 1.15fr);
    column-gap: clamp(2.5rem, 7vw, 8rem);
    align-items: start;
  }
  .learning-guide--text .study-panel__copy > :is(.label, h2){
    grid-column: 1;
  }
  .learning-guide--text .study-panel__copy > :not(.label, h2){
    grid-column: 2;
  }
  .learning-guide--text .study-panel__copy h2{
    max-width: 15ch;
    margin-bottom: 0;
    font-size: clamp(2rem, 2.8vw, 3rem);
    line-height: 1.06;
  }
  .learning-guide--text .learning-section{
    padding-block: clamp(3.5rem, 5vw, 5rem);
  }
  .learning-guide--text .learning-section__header{
    display: grid;
    grid-template-columns: minmax(0, .85fr) minmax(24rem, 1.15fr);
    column-gap: clamp(2.5rem, 7vw, 8rem);
    max-width: none;
    margin-bottom: clamp(2rem, 3vw, 3rem);
  }
  .learning-guide--text .learning-section__header :is(.label, h2){
    grid-column: 1;
  }
  .learning-guide--text .learning-section__header p{
    grid-column: 2;
    grid-row: 1 / span 2;
    align-self: end;
    max-width: 60ch;
    margin: 0;
  }
  .learning-guide--text .learning-section__header h2{
    max-width: 16ch;
    font-size: clamp(2rem, 2.8vw, 3rem);
    line-height: 1.06;
  }
}
@media (max-width: 900px){
  .learning-guide--text .study-panel__copy,
  .learning-guide--text .learning-section__header{
    display: block;
  }
}