.page-about {
  --about-rail-w: 176px;
  --about-gap: 40px;
  background: var(--lb-paper);
  color: var(--lb-ink);
  overflow-x: clip;
}

/* ---------- 面包屑 ---------- */
.page-about .about-crumb {
  padding-top: calc(var(--lb-bar-h) + var(--lb-header-h) + 18px);
}

/* ---------- 首屏主题声明 ---------- */
.page-about .about-masthead {
  position: relative;
  margin-top: -14px;
  padding: 34px 0 0;
  background:
    radial-gradient(120% 90% at 82% 0%, rgba(28, 139, 102, 0.55) 0%, rgba(14, 26, 36, 0) 62%),
    linear-gradient(180deg, var(--lb-ink) 0%, #0b1620 68%, var(--lb-pitch-deep) 100%);
  color: var(--lb-on-dark);
  overflow: hidden;
}

.page-about .about-masthead__inner {
  position: relative;
  z-index: 2;
  padding-bottom: 46px;
}

.page-about .about-kicker {
  margin: 0 0 18px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--lb-neon);
}

.page-about .about-title {
  margin: 0;
  max-width: 22em;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(30px, 7.5vw, 58px);
  line-height: 1.24;
  letter-spacing: -0.01em;
  color: var(--lb-paper);
}

.page-about .about-lead {
  margin: 22px 0 0;
  max-width: 46em;
  font-size: 16px;
  line-height: 1.85;
  color: var(--lb-on-dark);
}

.page-about .about-statband {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 40px 0 0;
  padding: 0;
  list-style: none;
  background: rgba(246, 248, 245, 0.16);
  border: 1px solid rgba(246, 248, 245, 0.16);
  border-radius: var(--lb-radius);
  overflow: hidden;
}

.page-about .about-statband__item {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 4px 6px;
  padding: 20px 18px 18px;
  background: rgba(14, 26, 36, 0.72);
}

.page-about .about-statband__value {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(26px, 6vw, 38px);
  line-height: 1;
  color: var(--lb-neon);
  font-variant-numeric: tabular-nums;
}

.page-about .about-statband__unit {
  font-size: 13px;
  color: var(--lb-on-dark-dim);
}

.page-about .about-statband__label {
  flex: 1 0 100%;
  font-size: 13px;
  line-height: 1.6;
  color: var(--lb-on-dark-dim);
}

/* ---------- 主体骨架 ---------- */
.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 28px;
  padding-top: 44px;
  padding-bottom: 72px;
}

.page-about .about-flow {
  min-width: 0;
}

/* 章节轨 —— 桌面 */
.page-about .about-rail {
  display: none;
}

.page-about .about-rail__title {
  margin: 0 0 14px;
  font-family: var(--font-sans);
  font-weight: 900;
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--lb-gray);
}

.page-about .about-rail__list {
  margin: 0;
  padding: 0 0 0 14px;
  list-style: none;
  border-left: 1px solid var(--lb-line);
}

.page-about .about-rail__link {
  display: block;
  padding: 7px 0;
  font-size: 14px;
  color: var(--lb-ink);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.2s var(--lb-ease), padding 0.2s var(--lb-ease);
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  color: var(--lb-pitch);
  padding-left: 6px;
}

/* 章节轨 —— 窄屏下拉 */
.page-about .about-rail-mobile {
  border: 1px solid var(--lb-line);
  border-radius: var(--lb-radius);
  background: #fff;
}

.page-about .about-rail-mobile__summary {
  display: flex;
  align-items: center;
  min-height: 48px;
  padding: 0 16px;
  font-family: var(--font-sans);
  font-weight: 900;
  font-size: 14px;
  letter-spacing: 0.04em;
  color: var(--lb-pitch-deep);
  cursor: pointer;
  list-style: none;
}

.page-about .about-rail-mobile__summary::-webkit-details-marker {
  display: none;
}

.page-about .about-rail-mobile__summary::after {
  content: "▾";
  margin-left: auto;
  font-size: 12px;
  color: var(--lb-pitch);
}

.page-about .about-rail-mobile[open] .about-rail-mobile__summary::after {
  content: "▴";
}

.page-about .about-rail-mobile__list {
  margin: 0;
  padding: 4px 8px 12px;
  list-style: none;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 4px;
}

.page-about .about-rail-mobile__list a {
  display: flex;
  align-items: center;
  min-height: 44px;
  padding: 0 10px;
  font-size: 14px;
  color: var(--lb-ink);
  text-decoration: none;
  border-radius: var(--lb-radius);
  background: var(--lb-paper);
}

.page-about .about-rail-mobile__list a:focus-visible {
  outline: 2px solid var(--lb-neon);
  outline-offset: -2px;
}

/* ---------- 章节通用 ---------- */
.page-about .about-chapter {
  position: relative;
  padding: 40px 0 48px;
  border-top: 1px solid var(--lb-line);
}

.page-about .about-chapter:first-child {
  border-top: 0;
  padding-top: 8px;
}

.page-about .about-chapter__head {
  max-width: 62ch;
  margin-bottom: 28px;
}

.page-about .about-chapter__index {
  display: inline-block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--lb-pitch);
  border-bottom: 2px solid var(--lb-neon);
  padding-bottom: 3px;
}

.page-about .about-chapter__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(23px, 5.2vw, 36px);
  line-height: 1.3;
  letter-spacing: -0.01em;
  color: var(--lb-ink);
}

.page-about .about-chapter__lead {
  margin: 14px 0 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--lb-gray);
}

.page-about .about-prose p {
  margin: 0 0 1.1em;
  font-size: 16px;
  line-height: 1.85;
  max-width: 62ch;
}

.page-about .about-prose p:last-child {
  margin-bottom: 0;
}

.page-about .about-figure {
  margin: 0 0 28px;
  border-radius: var(--lb-radius);
  overflow: hidden;
}

/* ---------- 时间轴 ---------- */
.page-about .about-timeline {
  position: relative;
  margin: 0;
  padding: 0 0 0 32px;
  list-style: none;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 6px;
  bottom: 6px;
  width: 2px;
  background: linear-gradient(180deg, var(--lb-pitch-light), var(--lb-pitch-deep));
}

.page-about .about-timeline__item {
  position: relative;
  padding: 0 0 30px;
}

.page-about .about-timeline__item:last-child {
  padding-bottom: 0;
}

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: -32px;
  top: 7px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--lb-neon);
  border: 3px solid var(--lb-paper);
  box-shadow: 0 0 0 2px var(--lb-pitch);
}

.page-about .about-timeline__meta {
  display: flex;
  align-items: baseline;
  gap: 10px;
  margin-bottom: 8px;
}

.page-about .about-timeline__gen {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: 15px;
  color: var(--lb-pitch-deep);
}

.page-about .about-timeline__era {
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--lb-gray);
}

.page-about .about-timeline__title {
  margin: 0 0 8px;
  font-family: var(--font-sans);
  font-weight: 900;
  font-size: 18px;
  line-height: 1.45;
  color: var(--lb-ink);
}

.page-about .about-timeline__body p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--lb-gray);
  max-width: 54ch;
}

.page-about .about-timeline__item:hover::before,
.page-about .about-timeline__item:focus-within::before {
  background: var(--lb-pitch-light);
  box-shadow: 0 0 0 2px var(--lb-neon);
}

.page-about .about-timeline__item:hover .about-timeline__title {
  color: var(--lb-pitch-deep);
}

/* ---------- 双栏交错 ---------- */
.page-about .about-split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 26px;
}

.page-about .about-split__aside {
  margin: 0;
  border-radius: var(--lb-radius);
  overflow: hidden;
}

/* ---------- 团队岗位 ---------- */
.page-about .about-roles {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-roles__card {
  padding: 20px 20px 22px;
  border-radius: var(--lb-radius);
  border: 1px solid var(--lb-line);
  transition: transform 0.25s var(--lb-ease), border-color 0.25s var(--lb-ease), box-shadow 0.25s var(--lb-ease);
}

.page-about .about-roles__card:hover,
.page-about .about-roles__card:focus-within {
  transform: translateY(-4px);
  border-color: var(--lb-pitch);
  box-shadow: var(--lb-shadow);
  outline: none;
}

.page-about .about-roles__card:focus-visible {
  outline: 2px solid var(--lb-neon);
  outline-offset: 2px;
}

.page-about .about-roles__tag {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--lb-pitch);
}

.page-about .about-roles__name {
  margin: 0 0 4px;
  font-family: var(--font-sans);
  font-weight: 900;
  font-size: 18px;
  color: var(--lb-ink);
}

.page-about .about-roles__count {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--lb-pitch-deep);
}

.page-about .about-roles__duty {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--lb-gray);
}

.page-about .about-train {
  margin-top: 24px;
  padding: 20px 22px;
  border-left: 4px solid var(--lb-neon);
  background: var(--lb-neon-soft);
  border-radius: 0 var(--lb-radius) var(--lb-radius) 0;
}

.page-about .about-train__title {
  margin: 0 0 8px;
  font-family: var(--font-sans);
  font-weight: 900;
  font-size: 16px;
  color: var(--lb-pitch-deep);
}

.page-about .about-train p {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--lb-ink);
}

/* ---------- 赛区 ---------- */
.page-about .about-regions {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
}

.page-about .about-regions__item {
  display: grid;
  gap: 4px;
  padding: 16px 18px;
  border-radius: var(--lb-radius);
  background: #fff;
  border: 1px solid var(--lb-line);
  border-left: 5px solid var(--lb-pitch);
}

.page-about .about-regions__item:nth-child(2) {
  border-left-color: var(--lb-pitch-light);
}

.page-about .about-regions__item:nth-child(3) {
  border-left-color: var(--lb-neon);
}

.page-about .about-regions__item:nth-child(4) {
  border-left-color: var(--lb-pitch-light);
}

.page-about .about-regions__item:nth-child(5) {
  border-left-color: var(--lb-pitch-deep);
}

.page-about .about-regions__name {
  font-family: var(--font-sans);
  font-weight: 900;
  font-size: 16px;
  letter-spacing: 0.04em;
  color: var(--lb-ink);
}

.page-about .about-regions__desc {
  font-size: 14px;
  line-height: 1.7;
  color: var(--lb-gray);
}

.page-about .about-audience {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
  margin-top: 30px;
}

.page-about .about-audience__card {
  padding: 22px 22px 24px;
  border-radius: var(--lb-radius);
  background: var(--lb-pitch);
  color: var(--lb-paper);
}

.page-about .about-audience__card:nth-child(2) {
  background: var(--lb-pitch-deep);
}

.page-about .about-audience__card:nth-child(3) {
  background: var(--lb-ink);
}

.page-about .about-audience__title {
  margin: 0 0 10px;
  font-family: var(--font-sans);
  font-weight: 900;
  font-size: 17px;
  color: var(--lb-neon);
}

.page-about .about-audience__card p {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--lb-on-dark);
}

/* ---------- 深色交付章节 ---------- */
.page-about .about-chapter--dark {
  margin: 0 -6vw;
  padding: 44px 6vw 48px;
  border-top: 0;
  background: linear-gradient(160deg, var(--lb-ink) 0%, var(--lb-pitch-deep) 100%);
  color: var(--lb-on-dark);
  border-radius: var(--lb-radius);
}

.page-about .about-chapter--dark .about-chapter__index {
  color: var(--lb-neon);
}

.page-about .about-chapter--dark .about-chapter__title {
  color: var(--lb-paper);
}

.page-about .about-deliver {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 26px;
}

.page-about .about-deliver__title {
  margin: 0 0 12px;
  font-family: var(--font-sans);
  font-weight: 900;
  font-size: 19px;
  color: var(--lb-neon);
}

.page-about .about-deliver__main p {
  margin: 0 0 16px;
  font-size: 15px;
  line-height: 1.85;
  color: var(--lb-on-dark);
  max-width: 56ch;
}

.page-about .about-deliver__list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 8px;
}

.page-about .about-deliver__list li {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 10px 0;
  border-bottom: 1px dashed rgba(246, 248, 245, 0.22);
  font-size: 14px;
  color: var(--lb-paper);
}

.page-about .about-deliver__list .about-num {
  color: var(--lb-neon);
}

.page-about .about-milestone {
  padding: 16px 18px;
  margin-bottom: 12px;
  border-radius: var(--lb-radius);
  background: rgba(246, 248, 245, 0.1);
  border-left: 3px solid var(--lb-neon);
}

.page-about .about-milestone:last-child {
  margin-bottom: 0;
}

.page-about .about-milestone__month {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--lb-neon);
}

.page-about .about-milestone__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--lb-on-dark);
}

.page-about .about-deliver__link {
  margin: 26px 0 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--lb-on-dark-dim);
}

.page-about .about-deliver__link a {
  color: var(--lb-neon);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ---------- 问答 ---------- */
.page-about .about-qa {
  display: grid;
  gap: 12px;
}

.page-about .about-qa__item {
  border: 1px solid var(--lb-line);
  border-radius: var(--lb-radius);
  background: #fff;
  overflow: hidden;
}

.page-about .about-qa__summary {
  display: flex;
  align-items: center;
  min-height: 56px;
  padding: 14px 18px;
  font-family: var(--font-sans);
  font-weight: 900;
  font-size: 16px;
  line-height: 1.5;
  color: var(--lb-ink);
  cursor: pointer;
  list-style: none;
}

.page-about .about-qa__summary::-webkit-details-marker {
  display: none;
}

.page-about .about-qa__summary::after {
  content: "＋";
  margin-left: auto;
  padding-left: 16px;
  font-family: var(--font-mono);
  color: var(--lb-pitch);
}

.page-about .about-qa__item[open] .about-qa__summary::after {
  content: "－";
}

.page-about .about-qa__item[open] .about-qa__summary {
  color: var(--lb-pitch-deep);
  background: var(--lb-neon-soft);
}

.page-about .about-qa__body {
  padding: 16px 18px 20px;
  border-top: 1px solid var(--lb-line);
}

.page-about .about-qa__body p {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--lb-gray);
  max-width: 56ch;
}

.page-about .about-qa__body a {
  color: var(--lb-pitch);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ---------- 结尾引导 ---------- */
.page-about .about-cta {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 18px;
  margin-top: 34px;
  padding: 26px 24px;
  border-radius: var(--lb-radius);
  background:
    linear-gradient(120deg, var(--lb-pitch) 0%, var(--lb-pitch-deep) 100%);
  color: var(--lb-paper);
}

.page-about .about-cta__title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 22px;
  color: var(--lb-paper);
}

.page-about .about-cta__text p {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--lb-on-dark);
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.page-about .about-note {
  margin-top: 20px;
  font-size: 13px;
  line-height: 1.8;
  color: var(--lb-gray);
}

.page-about .about-num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}

/* ---------- 焦点态 ---------- */
.page-about a:focus-visible,
.page-about summary:focus-visible {
  outline: 2px solid var(--lb-neon);
  outline-offset: 2px;
}

/* ---------- 平板 ---------- */
@media (min-width: 700px) {
  .page-about .about-statband {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-roles {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-roles__card:nth-child(even) {
    transform: translateY(18px);
  }

  .page-about .about-roles__card:nth-child(even):hover,
  .page-about .about-roles__card:nth-child(even):focus-within {
    transform: translateY(14px);
  }

  .page-about .about-regions {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-audience {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-deliver {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 34px;
  }

  .page-about .about-cta {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    padding: 30px 32px;
  }
}

/* ---------- 桌面：轨 + 交错时间轴 ---------- */
@media (min-width: 1080px) {
  .page-about .about-body {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: 56px;
    align-items: start;
  }

  .page-about .about-rail {
    display: block;
    position: sticky;
    top: calc(var(--lb-bar-h) + 92px);
  }

  .page-about .about-rail-mobile {
    display: none;
  }

  .page-about .about-chapter {
    padding: 48px 0 56px;
  }

  .page-about .about-chapter--dark {
    margin: 0 -3vw;
    padding: 56px 3vw 60px;
  }

  .page-about .about-split {
    grid-template-columns: minmax(0, 8fr) minmax(0, 5fr);
    gap: 40px;
    align-items: start;
  }

  .page-about .about-split--reverse {
    grid-template-columns: minmax(0, 5fr) minmax(0, 8fr);
  }

  .page-about .about-split--reverse .about-split__aside {
    order: -1;
  }

  .page-about .about-split__aside {
    position: sticky;
    top: calc(var(--lb-bar-h) + 96px);
  }

  .page-about .about-roles {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 16px;
  }

  .page-about .about-regions {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  /* 时间轴左右交错 */
  .page-about .about-timeline {
    padding-left: 0;
  }

  .page-about .about-timeline::before {
    left: 50%;
    transform: translateX(-1px);
  }

  .page-about .about-timeline__item {
    width: 50%;
    padding: 0 46px 40px 0;
    text-align: right;
  }

  .page-about .about-timeline__item::before {
    left: auto;
    right: -7px;
    top: 8px;
  }

  .page-about .about-timeline__item:nth-child(even) {
    margin-left: 50%;
    padding: 0 0 40px 46px;
    text-align: left;
  }

  .page-about .about-timeline__item:nth-child(even)::before {
    left: -7px;
    right: auto;
  }

  .page-about .about-timeline__meta {
    justify-content: flex-end;
  }

  .page-about .about-timeline__item:nth-child(even) .about-timeline__meta {
    justify-content: flex-start;
  }

  .page-about .about-timeline__body p {
    margin-left: auto;
  }

  .page-about .about-timeline__item:nth-child(even) .about-timeline__body p {
    margin-left: 0;
  }
}

/* ---------- 减少动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .about-roles__card,
  .page-about .about-rail__link {
    transition: none;
  }

  .page-about .about-roles__card:hover,
  .page-about .about-roles__card:focus-within,
  .page-about .about-roles__card:nth-child(even),
  .page-about .about-roles__card:nth-child(even):hover,
  .page-about .about-roles__card:nth-child(even):focus-within {
    transform: none;
  }
}