/* ============ 上手指引页 ============ */

.page-start .start-hero {
  background: var(--color-primary);
  color: var(--color-primary-ink);
  padding-block: var(--space-6) var(--space-8);
}

.page-start .start-hero__inner {
  display: grid;
  gap: var(--space-6);
}

.page-start .start-hero__crumb {
  color: color-mix(in srgb, var(--color-primary-ink) 76%, transparent);
  font-size: var(--text-sm);
  margin-bottom: var(--space-3);
}

.page-start .start-hero__crumb a {
  color: inherit;
  text-decoration: none;
  border-bottom: var(--border-thin) solid color-mix(in srgb, var(--color-primary-ink) 50%, transparent);
}

.page-start .start-hero__crumb a:hover,
.page-start .start-hero__crumb a:focus-visible {
  color: var(--color-primary-ink);
  border-bottom-color: var(--color-primary-ink);
}

.page-start .start-hero__crumb span[aria-current] {
  color: var(--color-primary-ink);
}

.page-start .start-hero__eyebrow {
  margin: 0 0 var(--space-2);
  font-size: var(--text-sm);
  letter-spacing: 0.08em;
  font-weight: 700;
  color: color-mix(in srgb, var(--color-primary-ink) 82%, transparent);
}

.page-start .start-hero__title {
  margin: 0;
  font-family: var(--font-heading);
  font-weight: 900;
  font-size: var(--text-display);
  line-height: 0.95;
  letter-spacing: -0.02em;
  color: var(--color-primary-ink);
}

.page-start .start-hero__lede {
  margin: var(--space-4) 0 0;
  max-width: var(--measure);
  font-size: var(--text-lg);
  line-height: var(--leading-body);
  color: color-mix(in srgb, var(--color-primary-ink) 88%, transparent);
}

.page-start .start-hero__figures {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: var(--border-thin) solid color-mix(in srgb, var(--color-primary-ink) 45%, transparent);
}

.page-start .start-fig {
  display: flex;
  align-items: baseline;
  gap: var(--space-3);
  padding-block: var(--space-2);
  border-bottom: var(--border-thin) solid color-mix(in srgb, var(--color-primary-ink) 45%, transparent);
}

.page-start .start-fig__num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: var(--text-figure);
  line-height: 0.9;
  letter-spacing: -0.02em;
  font-variant-numeric: tabular-nums;
  min-width: 2.2em;
  color: var(--color-primary-ink);
}

.page-start .start-fig__label {
  font-size: var(--text-sm);
  line-height: 1.45;
  color: color-mix(in srgb, var(--color-primary-ink) 86%, transparent);
}

/* ---------- 路径总览 ---------- */

.page-start .start-path {
  background: var(--color-surface-alt);
  padding-block: var(--space-6);
  border-bottom: var(--border-thin) solid var(--color-line);
}

.page-start .start-path__head {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  margin-bottom: var(--space-4);
}

.page-start .start-path__title {
  margin: 0;
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: var(--text-xl);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
}

.page-start .path-switch {
  display: flex;
  align-items: center;
}

.page-start .path-switch__input {
  position: absolute;
  width: 1px;
  height: 1px;
  opacity: 0;
  pointer-events: none;
}

.page-start .path-switch__tabs {
  display: flex;
  border: var(--border-thin) solid var(--color-line);
}

.page-start .path-switch__tab {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 44px;
  padding-inline: var(--space-3);
  font-size: var(--text-sm);
  font-weight: 700;
  color: var(--color-ink-soft);
  background: var(--color-surface);
  cursor: pointer;
  user-select: none;
}

.page-start .path-switch__tab + .path-switch__tab {
  border-left: var(--border-thin) solid var(--color-line);
}

.page-start .start-path:has(#path-mode-mobile:checked) .path-switch__tab[for="path-mode-mobile"],
.page-start .start-path:has(#path-mode-desktop:checked) .path-switch__tab[for="path-mode-desktop"] {
  background: var(--color-contrast-surface);
  color: var(--color-contrast-accent);
}

.page-start .path-switch__input:focus-visible ~ .path-switch__tabs {
  outline: var(--border-thick) solid var(--color-focus);
  outline-offset: 2px;
}

.page-start .start-path__figure {
  margin: 0;
}

.page-start .start-path__img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border: var(--border-thin) solid var(--color-line);
  background: var(--color-surface);
}

.page-start .start-path__caption {
  margin-top: var(--space-1);
  font-size: var(--text-xs);
  letter-spacing: 0.08em;
  color: var(--color-ink-muted);
}

.page-start .path-stage {
  margin-top: var(--space-4);
}

.page-start .path-map {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.page-start .path-map--desktop {
  display: none;
}

.page-start .start-path:has(#path-mode-desktop:checked) .path-map--mobile {
  display: none;
}

.page-start .start-path:has(#path-mode-desktop:checked) .path-map--desktop {
  display: flex;
}

.page-start .path-map__node {
  flex: 1 1 160px;
  position: relative;
  display: grid;
  gap: var(--space-1);
  align-content: start;
  padding: var(--space-3);
  background: var(--color-surface);
  border: var(--border-thin) solid var(--color-line);
  border-top: var(--space-1) solid var(--color-primary);
}

.page-start .path-map__dot {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: var(--text-xl);
  line-height: 1;
  color: var(--color-primary);
  font-variant-numeric: tabular-nums;
}

.page-start .path-map__name {
  font-weight: 700;
  font-size: var(--text-base);
  color: var(--color-ink);
}

.page-start .path-map__hint {
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
  line-height: 1.5;
}

/* ---------- 索引条 ---------- */

.page-start .start-index {
  background: var(--color-surface);
  border-bottom: var(--border-thin) solid var(--color-line);
  top: var(--header-h, 0px);
  z-index: 9;
}

.page-start .start-index .index-bar__track {
  display: flex;
  flex-wrap: nowrap;
  overflow-x: auto;
  scrollbar-width: none;
}

.page-start .start-index .index-bar__track::-webkit-scrollbar {
  display: none;
}

.page-start .start-index .index-bar__link {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding-inline: var(--space-3);
  font-size: var(--text-sm);
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--color-ink-soft);
  text-decoration: none;
  border-right: var(--border-thin) solid var(--color-line);
  white-space: nowrap;
}

.page-start .start-index .index-bar__link.is-current,
.page-start .start-index .index-bar__link:hover,
.page-start .start-index .index-bar__link:focus-visible {
  background: var(--color-primary);
  color: var(--color-primary-ink);
}

/* ---------- 分组与步骤 ---------- */

.page-start .start-group {
  padding-block: var(--section-y);
}

.page-start .start-group--deep {
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}

.page-start .start-group--surface {
  background: var(--color-surface);
  color: var(--color-ink);
}

.page-start .start-group__head {
  max-width: var(--measure);
  margin-bottom: var(--space-6);
}

.page-start .start-group__index {
  display: inline-block;
  padding: var(--space-1) var(--space-2);
  background: var(--color-primary);
  color: var(--color-primary-ink);
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.08em;
  margin-bottom: var(--space-3);
}

.page-start .start-group__title {
  margin: 0;
  font-family: var(--font-heading);
  font-weight: 900;
  font-size: var(--text-2xl);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
}

.page-start .start-group--deep .start-group__title {
  color: var(--color-contrast-ink);
}

.page-start .start-group__desc {
  margin: var(--space-3) 0 0;
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
}

.page-start .start-group--deep .start-group__desc {
  color: color-mix(in srgb, var(--color-contrast-ink) 78%, transparent);
}

.page-start .start-group__body {
  display: grid;
  gap: var(--space-6);
}

.page-start .start-group__figure {
  margin: 0;
}

.page-start .start-group__steps {
  min-width: 0;
}

.page-start .step-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-start .step-item {
  position: relative;
  padding-left: var(--space-8);
  padding-bottom: var(--space-6);
}

.page-start .step-item:last-child {
  padding-bottom: 0;
}

.page-start .step-item::before {
  content: "";
  position: absolute;
  left: calc(var(--space-6) / 2);
  top: var(--space-6);
  bottom: 0;
  width: var(--border-thin);
  background: var(--color-line);
}

.page-start .step-item:last-child::before {
  display: none;
}

.page-start .start-group--deep .step-item::before {
  background: var(--color-contrast-line);
}

.page-start .step-item__num {
  position: absolute;
  left: 0;
  top: 0;
  width: var(--space-6);
  height: var(--space-6);
  display: grid;
  place-items: center;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: var(--text-lg);
  font-variant-numeric: tabular-nums;
  background: var(--color-primary);
  color: var(--color-primary-ink);
  letter-spacing: -0.02em;
}

.page-start .step-item:nth-child(even) .step-item__num {
  background: var(--color-contrast-surface);
  color: var(--color-contrast-accent);
}

.page-start .start-group--deep .step-item__num,
.page-start .start-group--deep .step-item:nth-child(even) .step-item__num {
  background: var(--color-primary);
  color: var(--color-primary-ink);
}

.page-start .step-item__body {
  min-width: 0;
}

.page-start .step-item__title {
  margin: 0;
  font-family: var(--font-heading);
  font-weight: 700;
  font-size: var(--text-lg);
  line-height: 1.15;
  color: var(--color-ink);
}

.page-start .start-group--deep .step-item__title {
  color: var(--color-contrast-ink);
}

.page-start .step-item__meta {
  margin: var(--space-3) 0 0;
  display: grid;
  gap: var(--space-2);
}

.page-start .step-item__row {
  display: grid;
  gap: var(--space-1);
  padding-top: var(--space-2);
  border-top: var(--border-thin) solid var(--color-line);
}

.page-start .start-group--deep .step-item__row {
  border-top-color: var(--color-contrast-line);
}

.page-start .step-item__row dt {
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--color-primary);
}

.page-start .start-group--deep .step-item__row dt {
  color: var(--color-contrast-accent);
}

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

.page-start .start-group--deep .step-item__row dd {
  color: var(--color-contrast-ink);
}

.page-start .step-item__link {
  color: var(--color-accent);
  text-decoration: underline;
  text-underline-offset: 3px;
  font-weight: 700;
}

.page-start .start-group--deep .step-item__link {
  color: var(--color-contrast-accent);
}

.page-start .step-item__link:hover,
.page-start .step-item__link:focus-visible {
  color: var(--color-focus);
}

.page-start .start-group--deep .step-item__link:hover,
.page-start .start-group--deep .step-item__link:focus-visible {
  color: var(--color-primary-ink);
}

.page-start .step-item__result {
  margin: var(--space-3) 0 0;
  padding: var(--space-2) var(--space-3);
  background: var(--color-highlight);
  color: var(--color-ink);
  font-size: var(--text-sm);
  line-height: 1.6;
  max-width: var(--measure);
}

.page-start .step-item__result-tag {
  display: inline-block;
  margin-right: var(--space-2);
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--color-accent);
}

.page-start .start-group--deep .step-item__result {
  background: color-mix(in srgb, var(--color-accent) 34%, var(--color-contrast-surface));
  color: var(--color-contrast-ink);
}

.page-start .start-group--deep .step-item__result-tag {
  color: var(--color-contrast-accent);
}

.page-start .step-item__mark {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  min-height: 44px;
  margin-top: var(--space-2);
  padding-inline: var(--space-2);
  font-size: var(--text-sm);
  color: var(--color-ink-soft);
  cursor: pointer;
}

.page-start .start-group--deep .step-item__mark {
  color: color-mix(in srgb, var(--color-contrast-ink) 76%, transparent);
}

.page-start .step-item__mark:has(.step-item__box:checked) {
  background: var(--color-highlight);
  color: var(--color-ink);
}

.page-start .start-group--deep .step-item__mark:has(.step-item__box:checked) {
  background: color-mix(in srgb, var(--color-accent) 34%, var(--color-contrast-surface));
  color: var(--color-contrast-ink);
}

.page-start .step-item__box {
  appearance: none;
  -webkit-appearance: none;
  width: var(--space-3);
  height: var(--space-3);
  margin: 0;
  flex: none;
  display: grid;
  place-content: center;
  border: var(--border-thin) solid var(--color-ink-muted);
  background: transparent;
  cursor: pointer;
}

.page-start .start-group--deep .step-item__box {
  border-color: var(--color-contrast-line);
}

.page-start .step-item__box::after {
  content: "";
  width: var(--space-1);
  height: var(--space-1);
  background: var(--color-accent-ink);
  opacity: 0;
  transform: scale(0.4);
}

.page-start .step-item__box:checked {
  background: var(--color-accent);
  border-color: var(--color-accent);
}

.page-start .step-item__box:checked::after {
  opacity: 1;
  transform: scale(1);
}

.page-start .step-item__box:focus-visible {
  outline: var(--border-thick) solid var(--color-focus);
  outline-offset: 2px;
}

/* ---------- 常见卡点 ---------- */

.page-start .start-blocks {
  background: var(--color-surface-alt);
  padding-block: var(--section-y);
  border-top: var(--border-thin) solid var(--color-line);
}

.page-start .start-blocks__head {
  max-width: var(--measure);
  margin-bottom: var(--space-6);
}

.page-start .start-blocks__title {
  margin: 0;
  font-family: var(--font-heading);
  font-weight: 900;
  font-size: var(--text-2xl);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-ink);
}

.page-start .start-blocks__lede {
  margin: var(--space-3) 0 0;
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
}

.page-start .block-list {
  display: grid;
  gap: var(--space-2);
}

.page-start .block-item {
  background: var(--color-surface);
  border: var(--border-thin) solid var(--color-line);
}

.page-start .block-item__summary {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-3);
  min-height: 44px;
  padding: var(--space-3);
  cursor: pointer;
  list-style: none;
  font-size: var(--text-base);
  font-weight: 700;
  color: var(--color-ink);
}

.page-start .block-item__summary::-webkit-details-marker {
  display: none;
}

.page-start .block-item__summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: var(--text-xl);
  line-height: 1;
  color: var(--color-primary);
}

.page-start .block-item[open] .block-item__summary::after {
  content: "–";
}

.page-start .block-item[open] .block-item__summary {
  background: var(--color-primary);
  color: var(--color-primary-ink);
}

.page-start .block-item[open] .block-item__summary::after {
  color: var(--color-primary-ink);
}

.page-start .block-item__tag {
  flex: none;
  padding: var(--space-1) var(--space-2);
  background: var(--color-contrast-surface);
  color: var(--color-contrast-accent);
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.08em;
}

.page-start .block-item[open] .block-item__tag {
  background: var(--color-primary-ink);
  color: var(--color-primary);
}

.page-start .block-item__name {
  min-width: 0;
}

.page-start .block-item__panel {
  padding: var(--space-4);
  border-top: var(--border-thin) solid var(--color-line);
  display: grid;
  gap: var(--space-3);
}

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

.page-start .block-item__panel strong {
  color: var(--color-accent);
}

/* ---------- 下一步入口 ---------- */

.page-start .start-next {
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  padding-block: var(--section-y) var(--space-6);
}

.page-start .start-next__inner {
  display: grid;
  gap: var(--space-6);
}

.page-start .start-next__eyebrow {
  margin: 0 0 var(--space-2);
  font-size: var(--text-xs);
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--color-contrast-accent);
}

.page-start .start-next__title {
  margin: 0;
  font-family: var(--font-heading);
  font-weight: 900;
  font-size: var(--text-2xl);
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-contrast-ink);
}

.page-start .start-next__lede {
  margin: var(--space-3) 0 0;
  max-width: var(--measure);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: color-mix(in srgb, var(--color-contrast-ink) 78%, transparent);
}

.page-start .next-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: var(--space-2);
}

.page-start .next-item__link {
  display: grid;
  grid-template-columns: auto 1fr;
  grid-template-rows: auto auto;
  column-gap: var(--space-3);
  align-items: baseline;
  min-height: 44px;
  padding: var(--space-3);
  background: transparent;
  border: var(--border-thin) solid var(--color-contrast-line);
  text-decoration: none;
  color: var(--color-contrast-ink);
  transition: background-color 160ms linear, color 160ms linear;
}

.page-start .next-item__idx {
  grid-row: span 2;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: var(--text-xl);
  line-height: 1;
  color: var(--color-contrast-accent);
  font-variant-numeric: tabular-nums;
}

.page-start .next-item__label {
  font-weight: 700;
  font-size: var(--text-base);
}

.page-start .next-item__note {
  font-size: var(--text-sm);
  color: color-mix(in srgb, var(--color-contrast-ink) 72%, transparent);
}

.page-start .next-item__link:hover,
.page-start .next-item__link:focus-visible {
  background: var(--color-primary);
  color: var(--color-primary-ink);
}

.page-start .next-item__link:hover .next-item__idx,
.page-start .next-item__link:focus-visible .next-item__idx {
  color: var(--color-primary-ink);
}

.page-start .next-item__link:hover .next-item__note,
.page-start .next-item__link:focus-visible .next-item__note {
  color: color-mix(in srgb, var(--color-primary-ink) 82%, transparent);
}

.page-start .start-rule {
  margin-top: var(--space-6);
  height: var(--space-2);
  border-top: var(--border-thin) solid var(--color-contrast-line);
  background-image: repeating-linear-gradient(
    to right,
    var(--color-contrast-line) 0,
    var(--color-contrast-line) 1px,
    transparent 1px,
    transparent var(--space-3)
  );
  background-repeat: repeat-x;
  background-position: top left;
  background-size: var(--space-3) var(--space-2);
}

/* ---------- 响应式 ---------- */

@media (min-width: 720px) {
  .page-start .start-hero {
    padding-block: var(--space-8);
  }

  .page-start .start-path {
    padding-block: var(--space-8);
  }

  .page-start .start-group__body {
    grid-template-columns: minmax(0, 1fr);
  }
}

@media (min-width: 960px) {
  .page-start .start-hero__inner {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
    align-items: end;
    gap: var(--space-8);
  }

  .page-start .start-group__body {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: var(--space-8);
    align-items: start;
  }

  .page-start .start-group__body--flip {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
  }

  .page-start .start-group__figure {
    position: sticky;
    top: calc(var(--header-h, 0px) + var(--space-8));
  }

  .page-start .start-group__body--flip .start-group__figure {
    order: 2;
  }

  .page-start .start-next__inner {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.1fr);
    gap: var(--space-8);
    align-items: start;
  }

  .page-start .next-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 1200px) {
  .page-start .start-hero__figures {
    justify-self: end;
    width: 100%;
  }

  .page-start .start-fig__num {
    min-width: 2em;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-start .next-item__link,
  .page-start .step-item__box::after {
    transition: none;
  }
}
</main>

.page-start {
  --header-h: inherit;
}