.page-start {
  --start-toc-w: 236px;
  --start-hero-pad-top: calc(var(--section-y-lg) * 1.6);
  --start-hero-pad-bottom: calc(var(--section-y) * 1.1);
}

/* ---------- Hero ---------- */
.page-start .start-hero {
  position: relative;
  overflow: hidden;
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}

.page-start .start-hero__media {
  position: absolute;
  inset: 0;
}

.page-start .start-hero__media img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  object-position: center 42%;
}

.page-start .start-hero__veil {
  position: absolute;
  inset: 0;
  background: var(--overlay-scrim);
  pointer-events: none;
}

.page-start .start-hero__inner {
  position: relative;
  z-index: 1;
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
  justify-content: flex-end;
  min-height: 76vh;
  padding-block: var(--start-hero-pad-top) var(--space-6);
}

.page-start .start-hero__kicker {
  color: var(--color-contrast-ink);
  opacity: 0.8;
  margin: 0;
}

.page-start .start-hero__title {
  margin: 0;
  font-family: var(--font-heading);
  font-size: var(--text-display);
  font-weight: var(--weight-heading);
  line-height: 1.03;
  letter-spacing: var(--tracking-heading);
  color: var(--color-contrast-ink);
  max-width: 15ch;
}

.page-start .start-hero__lede {
  margin: 0;
  max-width: 52ch;
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-contrast-ink);
  opacity: 0.88;
}

.page-start .start-hero__figures {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-4) var(--space-8);
  margin-top: var(--space-2);
  padding-top: var(--space-4);
  border-top: var(--border-thin) solid var(--color-contrast-line);
}

.page-start .start-hero__figure {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.page-start .start-hero__num {
  display: block;
  font-family: var(--font-mono);
  font-size: var(--text-figure);
  font-weight: var(--weight-heading);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--color-contrast-accent);
}

.page-start .start-hero__figure-label {
  font-family: var(--font-mono);
  font-size: var(--text-sm);
  letter-spacing: 0.06em;
  color: var(--color-contrast-ink);
  opacity: 0.78;
}

.page-start .start-hero__note {
  position: static;
  margin: 0 var(--gutter) var(--space-6);
  color: var(--color-contrast-ink);
  opacity: 0.72;
}

/* ---------- Breadcrumb ---------- */
.page-start .start-crumb {
  padding-block: var(--space-4) 0;
}

/* ---------- Body shell ---------- */
.page-start .start-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--space-8);
  padding-block: var(--section-y);
}

/* ---------- TOC ---------- */
.page-start .start-toc {
  min-width: 0;
}

.page-start .start-toc__title {
  margin: 0 0 var(--space-4);
  color: var(--color-ink-muted);
}

.page-start .start-toc__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.page-start .start-toc__group-label {
  display: block;
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
  color: var(--color-ink-muted);
  text-transform: uppercase;
}

.page-start .start-toc__items {
  list-style: none;
  margin: var(--space-2) 0 0;
  padding: 0 0 0 var(--space-3);
  border-left: var(--border-thin) solid var(--color-line);
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.page-start .start-toc__items a {
  display: flex;
  align-items: baseline;
  gap: var(--space-2);
  padding: var(--space-1) var(--space-2);
  font-size: var(--text-sm);
  line-height: 1.5;
  color: var(--color-ink-soft);
  text-decoration: none;
  border-radius: var(--radius-sm);
  transition: background-color 160ms ease, color 160ms ease;
}

.page-start .start-toc__items a:hover {
  background-color: var(--color-primary-soft);
  color: var(--color-ink);
}

.page-start .start-toc__items a[aria-current="true"] {
  background-color: var(--color-primary);
  color: var(--color-primary-ink);
}

.page-start .start-toc__items a[aria-current="true"] .start-toc__no {
  color: var(--color-primary-ink);
  opacity: 0.8;
}

.page-start .start-toc__items a:focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: 2px;
}

.page-start .start-toc__no {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.04em;
  color: var(--color-ink-muted);
}

.page-start .start-toc__foot {
  margin: var(--space-6) 0 0;
  color: var(--color-ink-muted);
}

/* ---------- Article ---------- */
.page-start .start-article {
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: var(--section-y);
}

.page-start .start-group {
  display: flex;
  flex-direction: column;
  gap: var(--space-6);
}

.page-start .start-group__head {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.page-start .start-group__kicker {
  color: var(--color-ink-muted);
  margin: 0;
}

.page-start .start-group__title {
  margin: 0;
  font-family: var(--font-heading);
  font-size: var(--text-2xl);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
  max-width: 24ch;
}

.page-start .start-group__lede {
  margin: 0;
  max-width: var(--measure);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
}

/* ---------- Chapter ---------- */
.page-start .start-chapter {
  scroll-margin-top: 96px;
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  padding-left: var(--space-4);
  border-left: var(--border-thin) solid var(--color-line);
}

.page-start .start-chapter__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: var(--space-2) var(--space-3);
}

.page-start .start-chapter__no {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  padding: 2px var(--space-2);
  background-color: var(--color-primary);
  color: var(--color-primary-ink);
}

.page-start .start-chapter__title {
  margin: 0;
  flex: 1 1 12ch;
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
}

.page-start .start-chapter__time {
  color: var(--color-ink-muted);
  white-space: nowrap;
}

.page-start .start-chapter__body {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.page-start .start-chapter__body p {
  margin: 0;
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink);
}

.page-start .start-chapter__body a {
  color: var(--color-ink);
  text-decoration: underline;
  text-decoration-color: var(--color-primary);
  text-decoration-thickness: 2px;
  text-underline-offset: 3px;
  transition: background-color 160ms ease, color 160ms ease;
}

.page-start .start-chapter__body a:hover {
  background-color: var(--color-primary-soft);
}

.page-start .start-chapter__body a:focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: 2px;
}

/* ---------- Steps ---------- */
.page-start .start-steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.page-start .start-steps li {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: var(--space-2) var(--space-3);
  align-items: start;
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink);
}

.page-start .start-steps__id {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.04em;
  color: var(--color-ink-muted);
  padding-top: 5px;
  white-space: nowrap;
}

/* ---------- Note boxes ---------- */
.page-start .start-note {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
  padding: var(--space-4);
}

.page-start .start-note--primary {
  background-color: var(--color-primary-soft);
}

.page-start .start-note--accent {
  background-color: var(--color-highlight);
}

.page-start .start-note p {
  margin: 0;
  max-width: var(--measure);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink);
}

.page-start .start-note a {
  color: var(--color-ink);
  text-decoration: underline;
  text-decoration-color: var(--color-accent);
  text-decoration-thickness: 2px;
  text-underline-offset: 3px;
}

.page-start .start-note a:focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: 2px;
}

/* ---------- Summary ---------- */
.page-start .start-summary {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: var(--space-2);
  margin: var(--space-2) 0 0;
  padding-left: var(--space-3);
  border-left: 2px solid var(--color-accent);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
}

/* ---------- Figures ---------- */
.page-start .start-figure {
  margin: 0;
}

.page-start .start-figure--side {
  margin-bottom: var(--space-4);
}

.page-start .start-split {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

/* ---------- FAQ ---------- */
.page-start .start-faq {
  gap: var(--space-4);
}

.page-start .start-faq__item {
  border-left: 2px solid var(--color-line);
  padding-left: var(--space-3);
  transition: border-color 160ms ease;
}

.page-start .start-faq__item[open] {
  border-left-color: var(--color-accent);
}

.page-start .start-faq__item summary {
  cursor: pointer;
  padding: var(--space-2) 0;
  font-family: var(--font-heading);
  font-size: var(--text-lg);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  color: var(--color-ink);
}

.page-start .start-faq__item summary::marker {
  color: var(--color-accent);
}

.page-start .start-faq__item summary:focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: 2px;
}

.page-start .start-faq__body {
  padding-bottom: var(--space-3);
}

.page-start .start-faq__body p {
  margin: 0;
  max-width: var(--measure);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
}

.page-start .start-faq__body a {
  color: var(--color-ink);
  text-decoration: underline;
  text-decoration-color: var(--color-primary);
  text-decoration-thickness: 2px;
  text-underline-offset: 3px;
}

/* ---------- Next block ---------- */
.page-start .start-next {
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  padding-block: var(--section-y);
}

.page-start .start-next__inner {
  display: flex;
  flex-direction: column;
  gap: var(--space-4);
}

.page-start .start-next__kicker {
  color: var(--color-contrast-accent);
  margin: 0;
}

.page-start .start-next__title {
  margin: 0;
  max-width: 24ch;
  font-family: var(--font-heading);
  font-size: var(--text-2xl);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-contrast-ink);
}

.page-start .start-next__links {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--space-2);
}

.page-start .start-next__links a {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
  padding: var(--space-3) var(--space-4);
  border: var(--border-thin) solid var(--color-contrast-line);
  text-decoration: none;
  color: var(--color-contrast-ink);
  transition: background-color 160ms ease, border-color 160ms ease, color 160ms ease;
}

.page-start .start-next__links a:hover {
  background-color: var(--color-contrast-accent);
  border-color: var(--color-contrast-accent);
  color: var(--color-accent-ink);
}

.page-start .start-next__links a:focus-visible {
  outline: 2px solid var(--color-focus);
  outline-offset: 3px;
}

.page-start .start-next__link-label {
  font-family: var(--font-mono);
  font-size: var(--text-xs);
  letter-spacing: 0.1em;
}

.page-start .start-next__link-desc {
  font-size: var(--text-base);
  line-height: var(--leading-body);
  opacity: 0.86;
}

.page-start .start-next__meta {
  margin: 0;
  color: var(--color-contrast-ink);
  opacity: 0.66;
}

.page-start .start-next__meta a {
  color: var(--color-contrast-accent);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ---------- Wider screens ---------- */
@media (min-width: 640px) {
  .page-start .start-next__links {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 900px) {
  .page-start .start-hero__inner {
    min-height: 82vh;
    padding-block: var(--start-hero-pad-top) var(--start-hero-pad-bottom);
  }

  .page-start .start-hero__note {
    position: absolute;
    right: max(var(--gutter), calc((100% - var(--container)) / 2 + var(--gutter)));
    bottom: var(--space-8);
    z-index: 2;
    margin: 0;
    max-width: 28ch;
    text-align: right;
  }

  .page-start .start-split {
    display: grid;
    grid-template-columns: 260px minmax(0, 1fr);
    gap: var(--space-6);
    align-items: start;
  }

  .page-start .start-figure--side {
    margin-bottom: 0;
  }
}

@media (min-width: 980px) {
  .page-start .start-body {
    grid-template-columns: var(--start-toc-w) minmax(0, 1fr);
    gap: var(--space-8);
    align-items: start;
  }

  .page-start .start-toc {
    position: sticky;
    top: var(--space-8);
    align-self: start;
    max-height: calc(100vh - var(--space-8) * 2);
    overflow-y: auto;
  }
}