.tutorial-hero {
  position: relative;
  padding-top: clamp(64px, 8vw, 110px);
  padding-bottom: clamp(64px, 8vw, 104px);
  overflow: hidden;
  border-bottom: var(--line-thin) solid var(--color-border);
  background:
    linear-gradient(var(--color-grid) var(--line-thin), var(--color-transparent) var(--line-thin)),
    linear-gradient(90deg, var(--color-grid) var(--line-thin), var(--color-transparent) var(--line-thin)),
    var(--color-bg);
  background-size: 32px 32px;
}

.tutorial-hero::before {
  position: absolute;
  top: 12%;
  right: 4%;
  width: min(42vw, 560px);
  aspect-ratio: 1;
  pointer-events: none;
  border: var(--line-thin) dashed var(--color-border);
  border-radius: var(--radius-pill);
  opacity: 0.55;
  content: "";
}

.tutorial-hero::after {
  position: absolute;
  right: 18%;
  bottom: -180px;
  width: 420px;
  height: 420px;
  pointer-events: none;
  border-radius: var(--radius-pill);
  background: radial-gradient(circle, var(--color-teal-soft), var(--color-transparent) 68%);
  content: "";
}

.tutorial-hero-grid {
  position: relative;
  z-index: 2;
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(340px, 0.75fr);
  gap: clamp(38px, 8vw, 108px);
  align-items: center;
}

.tutorial-hero-copy {
  min-width: 0;
}

.tutorial-hero-copy h1 {
  max-width: 820px;
  margin-bottom: 24px;
}

.tutorial-hero-copy .lead {
  margin-bottom: 26px;
}

.tutorial-scope {
  max-width: 700px;
  margin-top: 22px;
  margin-bottom: 0;
  color: var(--color-text-muted);
  font-size: 14px;
}

.tutorial-scope a,
.tutorial-intro a,
.chapter-copy a,
.finish-grid a {
  color: var(--color-accent-dark);
  text-decoration: underline;
  text-decoration-color: var(--color-accent);
  text-underline-offset: 4px;
}

.lesson-route {
  position: relative;
  min-width: 0;
  padding: clamp(22px, 4vw, 34px);
  border: var(--line-thin) solid var(--color-glass-edge);
  border-radius: var(--radius-small);
  background: var(--color-paper-glass);
  box-shadow: var(--shadow-paper);
}

.lesson-route::before {
  position: absolute;
  inset: 9px;
  pointer-events: none;
  border: var(--line-thin) dashed var(--color-border-soft);
  border-radius: var(--radius-small);
  content: "";
}

.lesson-route-head {
  position: relative;
  z-index: 1;
  margin-bottom: 22px;
  padding-bottom: 16px;
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  border-bottom: var(--line-thin) solid var(--color-border-soft);
}

.lesson-route-head strong {
  font-size: 15px;
}

.lesson-route ol {
  position: relative;
  z-index: 1;
  margin: 0;
  padding: 0;
  display: grid;
  list-style: none;
}

.lesson-route ol::before {
  position: absolute;
  top: 25px;
  bottom: 25px;
  left: 22px;
  width: var(--line-thin);
  background: var(--color-border);
  content: "";
}

.lesson-route li {
  position: relative;
  min-width: 0;
  padding: 12px 0;
  display: grid;
  grid-template-columns: 46px minmax(0, 1fr);
  gap: 14px;
  align-items: center;
}

.route-index {
  position: relative;
  z-index: 1;
  width: 46px;
  height: 46px;
  display: grid;
  place-items: center;
  border: var(--line-thin) solid var(--color-border);
  border-radius: var(--radius-pill);
  color: var(--color-accent-dark);
  background: var(--color-panel);
  font-family: var(--font-mono);
  font-size: 11px;
  font-weight: 700;
}

.lesson-route li:nth-child(2) .route-index,
.lesson-route li:nth-child(4) .route-index {
  color: var(--color-success);
  background: var(--color-teal-soft);
}

.lesson-route li:nth-child(3) .route-index {
  color: var(--color-error);
  background: var(--color-coral-soft);
}

.lesson-route li strong,
.lesson-route li small {
  display: block;
}

.lesson-route li strong {
  font-size: 15px;
}

.lesson-route li small {
  margin-top: 3px;
  color: var(--color-text-muted);
  font-size: 12px;
}

.tutorial-intro {
  padding-bottom: clamp(52px, 7vw, 90px);
}

.tutorial-intro .toc-tabs {
  margin-bottom: 42px;
}

.tutorial-intro .callout {
  margin-bottom: clamp(48px, 7vw, 76px);
}

.tutorial-preparation {
  align-items: center;
}

.tutorial-preparation h2 {
  margin-bottom: 20px;
}

.preparation-sheet {
  background:
    linear-gradient(var(--color-grid) var(--line-thin), var(--color-transparent) var(--line-thin)),
    var(--color-panel);
  background-size: 100% 30px;
}

.preparation-sheet dl {
  margin: 24px 0 0;
}

.preparation-sheet dl div {
  padding: 14px 0;
  display: grid;
  grid-template-columns: 110px minmax(0, 1fr);
  gap: 18px;
  border-top: var(--line-thin) solid var(--color-border-soft);
}

.preparation-sheet dt {
  color: var(--color-accent-dark);
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
}

.preparation-sheet dd {
  margin: 0;
  color: var(--color-text-muted);
  font-size: 14px;
}

.tutorial-records .chapter-record {
  scroll-margin-top: calc(var(--header-height) + 28px);
}

.tutorial-records .chapter-copy > p {
  color: var(--color-text-muted);
}

.tutorial-records .chapter-copy h3 {
  margin-top: 2rem;
}

.tutorial-records .chapter-copy .callout p {
  color: var(--color-text);
}

.step-observation {
  position: sticky;
  top: calc(var(--header-height) + 82px);
  background:
    linear-gradient(90deg, var(--color-grid) var(--line-thin), var(--color-transparent) var(--line-thin)),
    var(--color-panel);
  background-size: 28px 100%;
}

.step-observation h3 {
  margin-top: 10px;
  font-size: 22px;
}

.step-observation > p:last-child {
  margin-bottom: 0;
  color: var(--color-text-muted);
  font-size: 14px;
}

.check-list,
.result-list {
  margin: 20px 0;
  padding: 0;
  display: grid;
  gap: 11px;
  list-style: none;
}

.check-list li {
  position: relative;
  padding-left: 25px;
  color: var(--color-text);
  font-size: 14px;
}

.check-list li::before {
  position: absolute;
  top: 0.65em;
  left: 2px;
  width: 9px;
  height: 9px;
  border: var(--line-thin) solid var(--color-success);
  border-radius: var(--radius-pill);
  background: var(--color-teal-soft);
  content: "";
}

.result-list {
  counter-reset: result-item;
}

.result-list li {
  position: relative;
  min-width: 0;
  padding: 10px 0 10px 42px;
  border-bottom: var(--line-thin) solid var(--color-border-soft);
  color: var(--color-text-muted);
  font-size: 14px;
  counter-increment: result-item;
}

.result-list li::before {
  position: absolute;
  top: 10px;
  left: 0;
  width: 28px;
  height: 28px;
  display: grid;
  place-items: center;
  border: var(--line-thin) solid var(--color-accent);
  border-radius: var(--radius-pill);
  color: var(--color-accent-dark);
  background: var(--color-amber-soft);
  font-family: var(--font-mono);
  font-size: 10px;
  content: counter(result-item);
}

.route-formula {
  margin: 20px 0;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
}

.route-formula span {
  min-width: 0;
  color: var(--color-text-muted);
  font-family: var(--font-mono);
  font-size: 11px;
}

.route-formula span:nth-child(odd) {
  padding: 7px 9px;
  border: var(--line-thin) solid var(--color-border-soft);
  border-radius: var(--radius-small);
  color: var(--color-text);
  background: var(--color-panel-soft);
}

.finish-grid {
  align-items: center;
}

.next-actions {
  border-top: 4px solid var(--color-accent);
}

.next-actions ul {
  margin: 22px 0 26px;
  padding: 0;
  display: grid;
  gap: 0;
  list-style: none;
}

.next-actions li {
  padding: 13px 0;
  border-bottom: var(--line-thin) solid var(--color-border-soft);
  color: var(--color-text-muted);
  font-size: 14px;
}

.next-actions li:first-child {
  border-top: var(--line-thin) solid var(--color-border-soft);
}

.next-actions li strong {
  color: var(--color-text);
}

@media (max-width: 900px) {
  .tutorial-hero-grid {
    grid-template-columns: minmax(0, 1fr);
  }

  .lesson-route {
    max-width: 680px;
  }

  .step-observation {
    position: static;
  }
}

@media (max-width: 640px) {
  .tutorial-hero {
    padding-top: 52px;
    padding-bottom: 60px;
  }

  .tutorial-hero::before {
    top: auto;
    right: -140px;
    bottom: -100px;
    width: 340px;
  }

  .tutorial-hero::after {
    right: -160px;
    bottom: -190px;
  }

  .tutorial-hero-grid {
    gap: 34px;
  }

  .tutorial-hero-copy h1 {
    margin-bottom: 18px;
  }

  .lesson-route-head {
    display: grid;
    gap: 6px;
  }

  .preparation-sheet dl div {
    grid-template-columns: minmax(0, 1fr);
    gap: 4px;
  }

  .route-formula {
    align-items: stretch;
    flex-direction: column;
  }

  .route-formula span {
    text-align: center;
  }

  .route-formula span:nth-child(even) {
    transform: rotate(90deg);
  }
}