.page-custom #start {
  scroll-margin-top: var(--space-8);
}

/* ---------- 首屏：深色数据带 ---------- */
.page-custom .hero {
  position: relative;
  overflow: hidden;
  background-color: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
}

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

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

.page-custom .hero__scrim {
  position: absolute;
  inset: 0;
  background: var(--overlay-scrim);
}

.page-custom .hero__rail {
  position: absolute;
  top: 0;
  bottom: 0;
  left: calc(50% - 540px);
  width: 2px;
  pointer-events: none;
  display: none;
  background: linear-gradient(
    180deg,
    transparent 0%,
    var(--color-contrast-line) 12%,
    var(--color-contrast-line) 88%,
    transparent 100%
  );
}

.page-custom .hero__rail span {
  position: absolute;
  left: -5px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--color-contrast-accent);
}

.page-custom .hero__rail span:nth-child(1) { top: 16%; }
.page-custom .hero__rail span:nth-child(2) { top: 49%; }
.page-custom .hero__rail span:nth-child(3) { top: 82%; }

.page-custom .hero__inner {
  position: relative;
  padding-top: var(--space-8);
  padding-bottom: var(--space-8);
}

.page-custom .hero__crumb {
  margin-bottom: var(--space-6);
}

.page-custom .hero .breadcrumb__link,
.page-custom .hero .breadcrumb__item {
  color: var(--color-contrast-accent);
}

.page-custom .hero .breadcrumb__item[aria-current] span,
.page-custom .hero .breadcrumb__item span[aria-current="page"] {
  color: var(--color-contrast-ink);
}

.page-custom .hero__title {
  margin: 0 0 var(--space-3);
  max-width: 15ch;
  font-family: var(--font-heading);
  font-size: var(--text-display);
  font-weight: 800;
  line-height: var(--leading-heading);
  letter-spacing: var(--tracking-heading);
  color: var(--color-contrast-ink);
}

.page-custom .hero__lede {
  margin: 0;
  max-width: var(--measure);
  font-size: var(--text-lg);
  line-height: var(--leading-body);
  color: var(--color-contrast-ink);
}

.page-custom .hero__figures {
  margin: var(--space-6) 0 0;
  padding: var(--space-4) 0 0;
  list-style: none;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--space-4) var(--space-3);
  border-top: var(--border-thin) solid var(--color-contrast-line);
}

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

.page-custom .stat__num {
  font-family: var(--font-mono);
  font-size: var(--text-figure);
  font-weight: 700;
  line-height: 1;
  font-variant-numeric: tabular-nums;
  color: var(--color-contrast-accent);
}

.page-custom .stat__label {
  font-size: var(--text-base);
  line-height: 1.4;
  color: var(--color-contrast-ink);
}

.page-custom .hero__jump {
  margin: var(--space-6) 0 0;
}

.page-custom .hero__jump a {
  display: inline-block;
  padding-bottom: 2px;
  font-size: var(--text-base);
  font-weight: 600;
  color: var(--color-contrast-accent);
  border-bottom: var(--border-thin) solid currentColor;
}

/* ---------- 处境 ---------- */
.page-custom .stuck {
  margin: var(--space-8) 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: var(--space-8);
}

.page-custom .stuck__item {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  column-gap: var(--space-3);
  row-gap: var(--space-2);
  align-items: start;
}

.page-custom .stuck__no {
  grid-row: 1 / span 2;
  padding-top: 5px;
  font-family: var(--font-mono);
  font-size: var(--text-lg);
  font-weight: 700;
  line-height: 1;
  color: var(--color-accent);
  font-variant-numeric: tabular-nums;
}

.page-custom .stuck__title {
  margin: 0;
  font-size: var(--text-xl);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  color: var(--color-ink);
}

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

/* ---------- 做法 ---------- */
.page-custom .methods {
  margin: var(--space-8) 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: var(--space-8);
}

.page-custom .method {
  padding-top: var(--space-3);
  border-top: var(--border-thin) solid var(--color-line);
}

.page-custom .method__tag {
  margin: 0 0 var(--space-1);
  font-size: var(--text-base);
  font-weight: 600;
  color: var(--color-accent);
}

.page-custom .method__title {
  margin: 0 0 var(--space-2);
  font-size: var(--text-2xl);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  color: var(--color-ink);
}

.page-custom .method__body {
  margin: 0 0 var(--space-3);
  max-width: var(--measure);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
}

.page-custom .method__specs {
  margin: 0;
  display: grid;
  gap: var(--space-3);
}

.page-custom .spec {
  margin: 0;
}

.page-custom .spec dt {
  margin-bottom: var(--space-1);
  font-size: var(--text-base);
  font-weight: 700;
  color: var(--color-primary);
}

.page-custom .spec dd {
  margin: 0;
  font-size: var(--text-base);
  line-height: 1.5;
  color: var(--color-ink);
}

/* ---------- 三条方向 ---------- */
.page-custom .tracks {
  margin-top: var(--space-8);
  display: grid;
  gap: var(--space-6);
}

.page-custom .track {
  border: var(--border-thin) solid var(--color-line);
  border-radius: var(--radius-lg);
  background: var(--color-surface);
}

.page-custom .track[open] {
  border-color: var(--color-primary);
  background: var(--color-surface-alt);
}

.page-custom .track__summary {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: var(--space-2) var(--space-3);
  padding: var(--space-3) var(--space-4);
  cursor: pointer;
  list-style: none;
  color: var(--color-ink);
  transition: background-color 120ms cubic-bezier(0.2, 0, 0.2, 1),
              color 120ms cubic-bezier(0.2, 0, 0.2, 1);
}

.page-custom .track__summary::-webkit-details-marker { display: none; }
.page-custom .track__summary::marker { content: ""; }

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

.page-custom .track[open] .track__summary {
  background: var(--color-contrast-surface);
  color: var(--color-contrast-ink);
  border-radius: var(--radius-lg) var(--radius-lg) 0 0;
}

.page-custom .track__tag {
  padding: 2px var(--space-1);
  border-radius: var(--radius-sm);
  background: var(--color-primary);
  color: var(--color-primary-ink);
  font-family: var(--font-mono);
  font-size: var(--text-base);
  font-weight: 700;
}

.page-custom .track[open] .track__tag {
  background: var(--color-contrast-accent);
  color: var(--color-contrast-surface);
}

.page-custom .track__name {
  flex: 1 1 auto;
  margin: 0;
  font-size: var(--text-xl);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
}

.page-custom .track__count {
  font-size: var(--text-base);
  font-variant-numeric: tabular-nums;
  color: var(--color-ink-muted);
}

.page-custom .track[open] .track__count {
  color: var(--color-contrast-ink);
}

.page-custom .track__summary::after {
  content: "＋";
  font-size: var(--text-xl);
  line-height: 1;
  color: var(--color-primary);
}

.page-custom .track[open] .track__summary::after {
  content: "－";
  color: var(--color-contrast-accent);
}

.page-custom .track__body {
  padding: var(--space-4);
  display: grid;
  gap: var(--space-4);
}

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

.page-custom .track__figure {
  margin: 0;
}

.page-custom .track__figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  aspect-ratio: 1000 / 640;
  object-fit: cover;
  border-radius: var(--radius-sm);
}

.page-custom .track__figure--wide img {
  aspect-ratio: 1200 / 700;
}

.page-custom .track__figure .figure-caption {
  margin-top: var(--space-2);
  font-size: var(--text-base);
  line-height: 1.5;
  color: var(--color-ink-muted);
}

.page-custom .idx {
  display: inline-block;
  min-width: 2.4em;
  font-family: var(--font-mono);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  color: var(--color-accent);
}

/* 表格方向 */
.page-custom .table-scroll {
  overflow-x: auto;
}

.page-custom .data-table {
  min-width: 560px;
}

.page-custom .data-table th[scope="row"] {
  text-align: left;
  font-weight: 600;
  color: var(--color-ink);
}

.page-custom .data-table tbody tr {
  transition: background-color 120ms cubic-bezier(0.2, 0, 0.2, 1);
}

.page-custom .data-table tbody tr:hover,
.page-custom .data-table tbody tr:focus-within {
  background: var(--color-primary);
}

.page-custom .data-table tbody tr:hover th,
.page-custom .data-table tbody tr:hover td,
.page-custom .data-table tbody tr:focus-within th,
.page-custom .data-table tbody tr:focus-within td {
  color: var(--color-primary-ink);
}

.page-custom .data-table tbody tr:hover .idx,
.page-custom .data-table tbody tr:focus-within .idx {
  color: var(--color-primary-ink);
}

/* 时间轴方向 */
.page-custom .timeline {
  position: relative;
  margin: 0;
  padding: 0 0 0 var(--space-4);
  list-style: none;
  display: grid;
  gap: var(--space-6);
}

.page-custom .timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: var(--color-line);
}

.page-custom .timeline__item {
  position: relative;
  display: grid;
  gap: var(--space-1);
}

.page-custom .timeline__dot {
  position: absolute;
  left: calc(-1 * var(--space-4));
  top: 6px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--color-surface-alt);
  border: var(--border-thin) solid var(--color-accent);
}

.page-custom .timeline__no {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--text-base);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  color: var(--color-accent);
}

.page-custom .timeline__title {
  margin: 0;
  font-size: var(--text-lg);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  color: var(--color-ink);
}

.page-custom .timeline__desc,
.page-custom .timeline__out {
  margin: 0;
  max-width: var(--measure);
  font-size: var(--text-base);
  line-height: var(--leading-body);
}

.page-custom .timeline__desc {
  color: var(--color-ink-soft);
}

.page-custom .timeline__out {
  font-weight: 600;
  color: var(--color-ink);
}

/* 对开两栏方向 */
.page-custom .split {
  display: grid;
  gap: var(--space-6);
}

.page-custom .split__col {
  display: grid;
  gap: var(--space-2);
  align-content: start;
  padding-top: var(--space-3);
  border-top: var(--border-thin) solid var(--color-accent);
}

.page-custom .split__no {
  margin: 0;
  font-family: var(--font-mono);
  font-size: var(--text-base);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  color: var(--color-accent);
}

.page-custom .split__title {
  margin: 0;
  font-size: var(--text-lg);
  font-weight: var(--weight-heading);
  line-height: var(--leading-heading);
  color: var(--color-ink);
}

.page-custom .split__desc,
.page-custom .split__out {
  margin: 0;
  font-size: var(--text-base);
  line-height: var(--leading-body);
}

.page-custom .split__desc {
  color: var(--color-ink-soft);
}

.page-custom .split__out {
  font-weight: 600;
  color: var(--color-ink);
}

/* ---------- 起步动作区 ---------- */
.page-custom .start-panel {
  padding: var(--space-6) var(--space-4);
  display: grid;
  gap: var(--space-6);
  background: var(--color-primary-soft);
  border: var(--border-thin) solid var(--color-primary);
  border-radius: var(--radius-lg);
}

.page-custom .start-panel__body {
  display: grid;
  gap: var(--space-3);
}

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

.page-custom .start-panel__list {
  margin: 0;
  padding-left: 1.3em;
  display: grid;
  gap: var(--space-1);
  font-size: var(--text-base);
  line-height: 1.6;
  color: var(--color-ink);
}

.page-custom .start-panel__actions {
  margin-top: var(--space-2);
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
}

.page-custom .start-panel__actions p {
  margin: 0;
}

.page-custom .start-panel__figure {
  margin: 0;
}

.page-custom .start-panel__figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  aspect-ratio: 1200 / 560;
  object-fit: cover;
  border-radius: var(--radius-sm);
}

.page-custom .start-panel__note {
  margin: var(--space-6) 0 0;
  max-width: var(--measure);
  font-size: var(--text-base);
  line-height: var(--leading-body);
  color: var(--color-ink-soft);
}

.page-custom .start-panel__note a {
  color: var(--color-primary);
  font-weight: 600;
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-custom .hero__inner {
    padding-top: var(--section-y);
    padding-bottom: var(--section-y);
  }

  .page-custom .hero__figures {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-custom .stuck {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: var(--space-8) var(--space-6);
  }

  .page-custom .stuck__item:first-child {
    grid-column: 1 / -1;
  }

  .page-custom .method__specs {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: var(--space-4);
  }

  .page-custom .track__body {
    padding: var(--space-6);
    gap: var(--space-6);
  }
}

@media (min-width: 860px) {
  .page-custom .split {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: var(--space-8);
  }

  .page-custom .start-panel {
    padding: var(--space-8);
    grid-template-columns: minmax(0, 1.25fr) minmax(0, 1fr);
    align-items: center;
  }
}

@media (min-width: 1140px) {
  .page-custom .hero__rail {
    display: block;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-custom .data-table tbody tr,
  .page-custom .track__summary {
    transition: none;
  }
}
<<<END>>>