:root {
  --ink: #0b1a1d;
  --ink-soft: #31474b;
  --paper: #f7faf9;
  --white: #ffffff;
  --teal: #0d7f82;
  --teal-bright: #20b7af;
  --teal-pale: #d7efeb;
  --line: rgba(11, 26, 29, 0.14);
  --container: min(1120px, calc(100% - 3rem));
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  min-width: 320px;
  color: var(--ink);
  background: var(--paper);
  font-family: "DM Sans", system-ui, sans-serif;
  font-size: 1rem;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
}
a { color: inherit; text-decoration: none; }
.skip-link {
  position: fixed;
  z-index: 100;
  top: .75rem;
  left: .75rem;
  padding: .7rem 1rem;
  color: var(--white);
  background: var(--ink);
  border-radius: 999px;
  transform: translateY(-160%);
}
.skip-link:focus { transform: translateY(0); }

.site-header {
  position: absolute;
  z-index: 10;
  inset: 0 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: var(--container);
  min-height: 5.5rem;
  margin-inline: auto;
  border-bottom: 1px solid var(--line);
}
.brand { display: grid; gap: .1rem; line-height: 1.2; }
.brand-name {
  font: 700 1.05rem/1.2 "Manrope", sans-serif;
  letter-spacing: -.02em;
}
.brand-detail {
  color: var(--ink-soft);
  font-size: .72rem;
  font-weight: 600;
  letter-spacing: .07em;
  text-transform: uppercase;
}
.home-link {
  display: inline-flex;
  align-items: center;
  gap: .7rem;
  padding: .65rem .9rem;
  border: 1px solid var(--line);
  border-radius: 999px;
  font-size: .88rem;
  font-weight: 700;
  transition: color .2s ease, border-color .2s ease, transform .2s ease;
}
.home-link:hover { color: var(--teal); border-color: var(--teal); transform: translateY(-2px); }

.intro {
  position: relative;
  display: grid;
  min-height: 78svh;
  align-items: center;
  overflow: hidden;
  padding: 9rem 0 5rem;
  background: radial-gradient(circle at 86% 38%, #dff2ee 0, transparent 31%), var(--paper);
}
.intro-inner { position: relative; z-index: 2; width: var(--container); margin-inline: auto; }
.intro-orbit {
  position: absolute;
  width: min(47rem, 70vw);
  aspect-ratio: 1;
  right: -13rem;
  top: 2rem;
  border: 1px solid rgba(13, 127, 130, .17);
  border-radius: 50%;
  box-shadow:
    0 0 0 5.5rem rgba(13, 127, 130, .025),
    0 0 0 11rem rgba(13, 127, 130, .018);
}
.eyebrow {
  display: flex;
  align-items: center;
  gap: .65rem;
  margin: 0 0 1.25rem;
  color: var(--teal);
  font-size: .78rem;
  font-weight: 700;
  letter-spacing: .12em;
  text-transform: uppercase;
}
.eyebrow span { width: 2.2rem; height: 1px; background: currentColor; }
h1, h2, p { margin-top: 0; }
h1, h2 { font-family: "Manrope", sans-serif; }
h1 {
  max-width: 54rem;
  margin-bottom: 1.6rem;
  font-size: clamp(4rem, 10vw, 8.5rem);
  font-weight: 600;
  line-height: .83;
  letter-spacing: -.07em;
}
h1 em {
  color: var(--teal);
  font-family: Georgia, serif;
  font-size: .9em;
  font-weight: 400;
}
.intro-copy {
  max-width: 42rem;
  margin-bottom: 2rem;
  color: var(--ink-soft);
  font-size: 1.12rem;
}
.intro-action {
  display: inline-flex;
  align-items: center;
  gap: 2.5rem;
  min-height: 3.4rem;
  padding: .8rem 1.2rem;
  color: var(--white);
  background: var(--ink);
  border-radius: 999px;
  font-size: .92rem;
  font-weight: 700;
  transition: background .2s ease, transform .2s ease;
}
.intro-action:hover { background: var(--teal); transform: translateY(-2px); }

.daily-discovery {
  width: var(--container);
  margin-inline: auto;
  padding: clamp(5rem, 9vw, 8rem) 0 1rem;
}
.daily-discovery-heading {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 2rem;
  margin-bottom: 2.4rem;
}
.daily-discovery-heading h2 {
  max-width: 42rem;
  margin-bottom: .85rem;
  font-size: clamp(2.7rem, 6vw, 5.4rem);
  font-weight: 600;
  line-height: .95;
  letter-spacing: -.06em;
  text-transform: uppercase;
}
.daily-discovery-heading > div > p:last-child {
  max-width: 40rem;
  margin-bottom: 0;
  color: var(--ink-soft);
  font-size: 1.05rem;
}
.refresh-discovery {
  display: inline-flex;
  min-height: 3rem;
  flex: 0 0 auto;
  align-items: center;
  gap: .75rem;
  padding: .7rem 1rem;
  color: var(--ink);
  background: transparent;
  border: 1px solid var(--line);
  border-radius: 999px;
  font: 700 .84rem/1 "DM Sans", sans-serif;
  cursor: pointer;
  transition: border-color .2s ease, color .2s ease, transform .2s ease;
}
.refresh-discovery:hover { color: var(--teal); border-color: var(--teal); transform: translateY(-2px); }
.refresh-discovery span { font-size: 1.15rem; transition: transform .25s ease; }
.refresh-discovery:hover span { transform: rotate(45deg); }
.discovery-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1.2rem;
  transition: opacity .14s ease, transform .14s ease;
}
.daily-discovery.is-changing .discovery-grid { opacity: .36; transform: translateY(3px); }
.discovery-card {
  position: relative;
  display: grid;
  min-width: 0;
  min-height: 29rem;
  overflow: hidden;
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: 1.7rem;
  box-shadow: 0 18px 55px rgba(3, 22, 24, .07);
  transition: border-color .22s ease, box-shadow .22s ease, transform .22s ease;
}
.discovery-card:hover { border-color: rgba(13, 127, 130, .36); box-shadow: 0 24px 65px rgba(3, 22, 24, .11); transform: translateY(-3px); }
.discovery-card.structure,
.discovery-card.movement,
.discovery-card.history { grid-template-columns: minmax(10rem, .75fr) minmax(0, 1.25fr); }
.discovery-media { min-height: 100%; overflow: hidden; background: #e6eeeb; }
.discovery-media img { width: 100%; height: 100%; object-fit: contain; display: block; }
.discovery-card-body { display: flex; min-width: 0; flex-direction: column; padding: clamp(1.5rem, 3vw, 2.3rem); }
.discovery-meta { display: flex; align-items: center; justify-content: space-between; gap: 1rem; margin-bottom: 2rem; }
.discovery-meta span {
  color: var(--teal);
  font-size: .7rem;
  font-weight: 800;
  letter-spacing: .14em;
}
.discovery-meta small { overflow: hidden; color: #66777a; font-size: .65rem; font-weight: 700; text-overflow: ellipsis; white-space: nowrap; }
.discovery-card h3 {
  margin: 0 0 1rem;
  font: 600 clamp(1.75rem, 3vw, 2.8rem)/1.04 "Manrope", sans-serif;
  letter-spacing: -.045em;
}
.discovery-card p { margin-bottom: 1.4rem; color: var(--ink-soft); font-size: .94rem; line-height: 1.6; }
.discovery-link {
  display: flex;
  min-height: 2.9rem;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  margin-top: auto;
  padding-top: .8rem;
  border-top: 1px solid var(--line);
  font-size: .87rem;
  font-weight: 700;
}
.discovery-link span { color: var(--teal); font-size: 1.2rem; transition: transform .2s ease; }
.discovery-link:hover span { transform: translateX(4px); }
.question-body { padding: clamp(1.5rem, 3vw, 2.6rem); }
.question .discovery-meta span { color: #956f27; }
.daily-options { display: grid; gap: .55rem; margin: .15rem 0 1.2rem; }
.daily-options button {
  display: grid;
  grid-template-columns: 2rem minmax(0, 1fr);
  min-height: 3.25rem;
  align-items: center;
  gap: .65rem;
  padding: .55rem .8rem;
  color: var(--ink);
  text-align: left;
  background: #f4f7f6;
  border: 1px solid transparent;
  border-radius: .8rem;
  font: 600 .88rem/1.35 "DM Sans", sans-serif;
  cursor: pointer;
  transition: background .18s ease, border-color .18s ease;
}
.daily-options button:hover:not(:disabled) { background: var(--teal-pale); border-color: rgba(13, 127, 130, .3); }
.daily-options button:disabled { cursor: default; opacity: .68; }
.daily-options button.is-correct { color: #075f5b; background: #e0f3ef; border-color: #7bc4ba; opacity: 1; }
.daily-options button.is-wrong { color: #7c3e34; background: #f9e9e5; border-color: #daa99f; opacity: 1; }
.daily-options b { display: grid; width: 1.9rem; aspect-ratio: 1; place-items: center; border: 1px solid currentColor; border-radius: 50%; font-size: .7rem; }
.daily-feedback { display: none; margin-bottom: 1.2rem; padding: .9rem 1rem; background: #f4f7f6; border-radius: .9rem; }
.daily-feedback.is-visible { display: block; }
.daily-feedback strong { display: block; color: var(--teal); font-size: .75rem; letter-spacing: .08em; }
.daily-feedback.wrong strong { color: #9b5547; }
.daily-feedback p { margin: .35rem 0 0; font-size: .82rem; }
.term { background: linear-gradient(145deg, #0b1a1d, #10292c); color: var(--white); border-color: transparent; }
.term .discovery-meta small, .term p { color: rgba(255, 255, 255, .65); }
.term .discovery-meta span, .term .discovery-link span { color: var(--teal-bright); }
.term .discovery-link { border-color: rgba(255, 255, 255, .16); }
.number { grid-column: 1 / -1; min-height: 20rem; background: linear-gradient(130deg, #e8f5f1, #fff); }
.number .discovery-card-body { max-width: 52rem; }
.number h3 { color: var(--teal); font-size: clamp(4.5rem, 10vw, 8rem); line-height: .78; }
.number .discovery-meta span { color: #956f27; }
.discovery-more {
  display: inline-flex;
  min-height: 3.2rem;
  align-items: center;
  gap: 1.2rem;
  margin-top: 1.5rem;
  padding: .75rem 1.05rem;
  color: var(--white);
  background: var(--ink);
  border-radius: 999px;
  font-size: .86rem;
  font-weight: 700;
  transition: background .2s ease, transform .2s ease;
}
.discovery-more:hover { background: var(--teal); transform: translateY(-2px); }

.guided-route-teaser {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr) auto;
  gap: 2rem;
  align-items: end;
  width: var(--container);
  min-height: 24rem;
  margin: 5rem auto 1rem;
  padding: clamp(1.6rem, 5vw, 4rem);
  overflow: hidden;
  color: var(--white);
  background: #0a6265;
  border-radius: 2rem;
  box-shadow: 0 24px 65px rgba(3, 22, 24, .13);
}
.guided-route-teaser::after {
  position: absolute;
  width: 24rem;
  aspect-ratio: 1;
  right: -8rem;
  top: -11rem;
  border: 1px solid rgba(255, 255, 255, .22);
  border-radius: 50%;
  box-shadow: 0 0 0 4rem rgba(255, 255, 255, .04), 0 0 0 8rem rgba(255, 255, 255, .025);
  content: "";
  pointer-events: none;
}
.guided-route-copy,
.guided-route-actions { position: relative; z-index: 1; }
.guided-route-copy .eyebrow { color: rgba(255, 255, 255, .72); }
.guided-route-copy > small { display: block; margin-bottom: .8rem; font-size: .7rem; font-weight: 700; letter-spacing: .14em; }
.guided-route-copy h2 { max-width: 14ch; margin-bottom: 1rem; font-size: clamp(2.5rem, 6vw, 5rem); line-height: .95; letter-spacing: -.055em; }
.guided-route-copy > p:not(.eyebrow) { max-width: 42rem; color: rgba(255, 255, 255, .75); }
.guided-route-meta { display: flex; flex-wrap: wrap; gap: .6rem; }
.guided-route-meta span { padding: .45rem .7rem; border: 1px solid rgba(255, 255, 255, .26); border-radius: 999px; font-size: .82rem; font-weight: 700; }
.guided-route-dots { display: flex; gap: .4rem; margin-top: 1.2rem; }
.guided-route-dots i { width: .48rem; height: .48rem; background: rgba(255, 255, 255, .36); border-radius: 50%; }
.guided-route-dots i:first-child { background: white; }
.guided-route-actions { display: grid; min-width: 15rem; gap: .7rem; }
.guided-route-actions a,
.guided-route-actions button { display: inline-flex; min-height: 3.1rem; align-items: center; justify-content: center; gap: .6rem; padding: .7rem 1rem; color: var(--ink); background: white; border: 1px solid white; border-radius: 999px; font: 700 .86rem/1 "DM Sans", sans-serif; cursor: pointer; }
.guided-route-actions button { color: white; background: transparent; border-color: rgba(255, 255, 255, .3); }
.guided-route-actions .all-routes-link { min-height: auto; padding: .45rem; color: rgba(255, 255, 255, .75); background: transparent; border: 0; }
.refresh-discovery:focus-visible,
.discovery-link:focus-visible,
.discovery-more:focus-visible,
.guided-route-actions a:focus-visible,
.guided-route-actions button:focus-visible,
.daily-options button:focus-visible {
  outline: 3px solid rgba(13, 127, 130, .42);
  outline-offset: 3px;
}

.library {
  width: var(--container);
  margin-inline: auto;
  padding: clamp(5rem, 9vw, 8rem) 0;
}
.library-heading {
  display: flex;
  align-items: end;
  justify-content: space-between;
  gap: 2rem;
  margin-bottom: 2.5rem;
}
.library-heading h2 {
  margin-bottom: 0;
  font-size: clamp(2.4rem, 5vw, 4.8rem);
  font-weight: 600;
  line-height: 1;
  letter-spacing: -.055em;
}
.content-count {
  padding-bottom: .45rem;
  color: var(--ink-soft);
  font-size: .82rem;
  font-weight: 700;
  letter-spacing: .08em;
  text-transform: uppercase;
}
.content-card {
  display: grid;
  grid-template-columns: minmax(18rem, .78fr) minmax(0, 1.22fr);
  overflow: hidden;
  color: var(--white);
  background: var(--ink);
  border-radius: 2rem;
  box-shadow: 0 25px 80px rgba(3, 22, 24, .14);
  transition: transform .25s ease, box-shadow .25s ease;
}
.content-card:hover {
  transform: translateY(-6px);
  box-shadow: 0 32px 90px rgba(3, 22, 24, .2);
}
.content-card + .content-card { margin-top: 1.4rem; }
.anatomy-card .card-visual { background: #e8e3d9; }
.anatomy-card .card-visual::before { width: 12rem; height: 24rem; right: 2rem; top: 3rem; border-radius: 48% 48% 38% 38%; }
.anatomy-card .card-visual::after { width: 1px; height: 72%; left: 50%; bottom: 14%; border: 0; border-left: 1px solid rgba(13,127,130,.22); border-radius: 0; }
.minute-card .card-visual { background: #ece7dc; }
.minute-card .card-visual::before { width: 15rem; height: 15rem; right: -3rem; top: 3rem; border-color: rgba(220, 118, 95, .25); }
.minute-card .card-visual::after { width: 8rem; height: 8rem; left: 2rem; bottom: 4rem; box-shadow: 0 0 0 3.8rem rgba(13, 127, 130, .035); }
.minute-card .card-visual i { background: #dc765f; box-shadow: 0 0 0 .55rem rgba(220, 118, 95, .18); }
.daily-card .card-visual { background: #e4ebe7; }
.daily-card .card-visual::before { width: 18rem; height: 18rem; right: -4rem; top: -5rem; border-color: rgba(13, 127, 130, .28); }
.daily-card .card-visual::after { width: 10rem; height: 20rem; left: 3rem; bottom: -7rem; border-radius: 48% 48% 42% 42%; border-color: rgba(220, 118, 95, .22); }
.daily-card .card-visual i { background: #c9a45d; box-shadow: 0 0 0 .55rem rgba(201, 164, 93, .18); }
.glossary-card .card-visual { background: #e2e8e5; }
.glossary-card .card-visual::before { width: 18rem; height: 18rem; right: -5rem; top: -6rem; border-color: rgba(201,164,93,.35); }
.glossary-card .card-visual::after { width: 12rem; height: 12rem; left: 1.5rem; bottom: 2rem; border-color: rgba(13,127,130,.24); box-shadow: 0 0 0 3.5rem rgba(13,127,130,.025); }
.glossary-card .card-visual i { background: #0d7f82; box-shadow: 0 0 0 .55rem rgba(13,127,130,.16); }
.exercise-card .card-visual{background:#dfe8e4}.exercise-card .card-visual::before{width:20rem;height:20rem;right:-5rem;top:-6rem;border-color:rgba(220,118,95,.3)}.exercise-card .card-visual::after{width:13rem;height:22rem;left:2.2rem;bottom:-8rem;border-radius:48% 48% 40% 40%;border-color:rgba(13,127,130,.28)}.exercise-card .card-visual i{background:#dc765f;box-shadow:0 0 0 .55rem rgba(220,118,95,.16)}
.quiz-card .card-visual{background:#e2ece9}.quiz-card .card-visual::before{width:19rem;height:19rem;right:-5rem;top:-5rem;border-color:rgba(13,127,130,.32)}.quiz-card .card-visual::after{width:10rem;height:10rem;left:2rem;bottom:4rem;border-color:rgba(201,164,93,.4);box-shadow:0 0 0 4rem rgba(201,164,93,.035)}.quiz-card .card-visual i{background:#c9a45d;box-shadow:0 0 0 .55rem rgba(201,164,93,.18)}
.card-visual {
  position: relative;
  display: flex;
  min-height: 30rem;
  flex-direction: column;
  justify-content: space-between;
  overflow: hidden;
  padding: clamp(2rem, 4vw, 3.4rem);
  color: var(--ink);
  background: var(--teal-pale);
}
.card-visual::before,
.card-visual::after {
  content: "";
  position: absolute;
  border: 1px solid rgba(13, 127, 130, .2);
  border-radius: 50%;
}
.card-visual::before { width: 21rem; height: 21rem; right: -10rem; top: -7rem; }
.card-visual::after { width: 14rem; height: 14rem; left: -7rem; bottom: -6rem; }
.card-visual strong {
  position: relative;
  z-index: 1;
  font: 700 clamp(6.5rem, 15vw, 11rem)/.75 "Manrope", sans-serif;
  letter-spacing: -.08em;
}
.visual-kicker,
.visual-meta {
  position: relative;
  z-index: 1;
  font-size: .74rem;
  font-weight: 800;
  letter-spacing: .13em;
}
.card-visual i {
  position: absolute;
  right: 2.2rem;
  bottom: 2rem;
  width: 1rem;
  height: 1rem;
  background: var(--teal-bright);
  border-radius: 50%;
  box-shadow: 0 0 0 .55rem rgba(32, 183, 175, .18);
}
.card-copy {
  display: flex;
  min-width: 0;
  flex-direction: column;
  padding: clamp(2.2rem, 5vw, 4.5rem);
}
.card-type {
  margin-bottom: auto;
  color: var(--teal-bright);
  font-size: .75rem;
  font-weight: 700;
  letter-spacing: .1em;
  text-transform: uppercase;
}
.card-title {
  display: block;
  max-width: 39rem;
  margin: 3rem 0 .85rem;
  font: 600 clamp(2.5rem, 5vw, 4.9rem)/.98 "Manrope", sans-serif;
  letter-spacing: -.055em;
}
.card-subtitle {
  color: var(--teal-bright);
  font: 700 1rem/1.3 "Manrope", sans-serif;
}
.card-description {
  display: block;
  max-width: 37rem;
  margin-top: 1.6rem;
  color: rgba(255, 255, 255, .65);
  font-size: 1rem;
}
.card-action {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 3rem;
  padding-top: 1rem;
  border-top: 1px solid rgba(255, 255, 255, .16);
  font-size: .95rem;
  font-weight: 700;
}
.card-action b { color: var(--teal-bright); font-size: 1.35rem; font-weight: 400; }

footer {
  display: grid;
  grid-template-columns: .7fr 1.4fr auto;
  gap: 3rem;
  align-items: end;
  padding: 3.2rem max(1.5rem, calc((100% - 1120px) / 2));
  color: rgba(255, 255, 255, .65);
  background: #061013;
}
footer div { display: grid; }
footer strong { color: var(--white); font-family: "Manrope", sans-serif; }
footer span, footer p { margin: 0; font-size: .73rem; line-height: 1.6; }
footer > span { white-space: nowrap; }

@media (max-width: 760px) {
  :root { --container: calc(100% - 2rem); }
  .site-header { min-height: 4.8rem; }
  .brand-detail { font-size: .58rem; }
  .home-link { padding: .55rem .7rem; font-size: .76rem; }
  .intro { min-height: 72svh; padding-top: 8rem; }
  .intro-orbit { width: 35rem; right: -24rem; }
  h1 { font-size: clamp(4rem, 22vw, 6.4rem); }
  .intro-copy { font-size: 1rem; }
  .daily-discovery { padding-top: 4.5rem; }
  .daily-discovery-heading { align-items: start; flex-direction: column; }
  .daily-discovery-heading h2 { font-size: clamp(2.65rem, 14vw, 4rem); }
  .refresh-discovery { width: 100%; justify-content: center; }
  .discovery-grid { grid-template-columns: 1fr; }
  .discovery-card { min-height: 0; border-radius: 1.35rem; }
  .discovery-card.structure,
  .discovery-card.movement,
  .discovery-card.history { grid-template-columns: 1fr; }
  .discovery-media { min-height: 13rem; max-height: 17rem; }
  .discovery-card-body { min-height: 20rem; }
  .question-body { min-height: 0; }
  .discovery-meta { margin-bottom: 1.4rem; }
  .daily-options button { min-height: 3.5rem; }
  .discovery-more { width: 100%; justify-content: space-between; }
  .guided-route-teaser { grid-template-columns: 1fr; min-height: 31rem; margin-top: 3.5rem; padding: 1.4rem; }
  .guided-route-actions { min-width: 0; }
  .guided-route-actions a, .guided-route-actions button { width: 100%; }
  .library-heading { align-items: start; flex-direction: column; gap: 1rem; }
  .content-card { grid-template-columns: 1fr; border-radius: 1.4rem; }
  .card-visual { min-height: 19rem; }
  .card-copy { min-height: 28rem; }
  .card-type { margin-bottom: 0; }
  .card-title { margin-top: 2rem; }
  .card-description { font-size: 1rem; }
  .card-action { margin-top: auto; }
  footer { grid-template-columns: 1fr; gap: 1.4rem; align-items: start; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition-duration: .01ms !important; }
}