.page-about {
  --about-year-size: clamp(44px, 12vw, 66px);
  --about-shift: clamp(0px, 2vw, 22px);
  background-color: var(--lj-ink);
  color: var(--lj-text);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: calc(var(--lj-header-h) + clamp(28px, 6vw, 64px)) 0 clamp(48px, 8vw, 92px);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0 -6% 0 40%;
  z-index: 0;
  background: linear-gradient(158deg, rgba(14, 33, 27, 0.96), rgba(7, 19, 16, 0.32));
  clip-path: polygon(26% 0, 100% 0, 100% 100%, 0 100%);
  pointer-events: none;
}

.page-about .about-hero > .lj-container {
  position: relative;
  z-index: 1;
}

.page-about .about-hero__eyebrow {
  margin-top: clamp(20px, 4vw, 40px);
}

.page-about .about-hero__title {
  margin: 14px 0 0;
  max-width: 18ch;
}

.page-about .about-hero__lead {
  margin-top: clamp(16px, 3vw, 24px);
  max-width: 56ch;
  color: var(--lj-muted);
}

.page-about .about-figures {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(32px, 6vw, 60px) 0 0;
  padding: 1px;
  list-style: none;
  background-color: var(--lj-line);
  border: 1px solid var(--lj-line);
}

.page-about .about-figures__item {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: clamp(14px, 3vw, 24px) clamp(12px, 2.4vw, 20px);
  background-color: var(--lj-ink);
}

.page-about .about-figures__num {
  font-family: var(--lj-font-num);
  font-size: clamp(30px, 6.4vw, 50px);
  line-height: 1;
  font-weight: 700;
  letter-spacing: -0.03em;
}

.page-about .about-figures__label {
  font-size: 14px;
  line-height: 1.55;
  color: var(--lj-muted);
}

/* ---------- 章节通用 ---------- */
.page-about .about-section {
  padding: clamp(48px, 9vw, 104px) 0;
}

.page-about .about-section .lj-section__head {
  margin-bottom: clamp(24px, 4vw, 44px);
}

/* ---------- 起点 ---------- */
.page-about .about-start__text p {
  color: var(--lj-muted);
  max-width: 62ch;
}

.page-about .about-start__text .lj-h2 {
  margin: 12px 0 clamp(14px, 2.4vw, 22px);
}

.page-about .about-start__text p + p {
  margin-top: 14px;
}

.page-about .about-start__text .lj-meta {
  margin-top: clamp(18px, 3vw, 28px);
  color: var(--lj-soft);
}

.page-about .about-start__media {
  margin: clamp(28px, 6vw, 0px) 0 0;
}

.page-about .about-start__media .lj-media__caption {
  margin-top: 12px;
  font-size: 14px;
  line-height: 1.6;
  color: var(--lj-muted);
}

.page-about .lj-media__img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}

/* ---------- 时间线 ---------- */
.page-about .about-timeline {
  position: relative;
  background:
    linear-gradient(180deg, rgba(14, 33, 27, 0.55), rgba(7, 19, 16, 0));
  border-top: 1px solid var(--lj-line);
}

.page-about .about-timeline__banner {
  margin: 0 0 clamp(24px, 4vw, 40px);
}

.page-about .about-yearbar {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding: 4px 0 12px;
  scroll-snap-type: x proximity;
  scrollbar-width: thin;
  scrollbar-color: var(--lj-line) transparent;
}

.page-about .about-yearbar__link {
  flex: 0 0 auto;
  scroll-snap-align: start;
  text-decoration: none;
  font-family: var(--lj-font-num);
}

.page-about .about-nodes {
  position: relative;
  list-style: none;
  margin: clamp(20px, 4vw, 36px) 0 0;
  padding: 0;
}

.page-about .about-nodes::before {
  content: "";
  position: absolute;
  top: 8px;
  bottom: 32px;
  left: 9px;
  width: 1px;
  background: linear-gradient(180deg, var(--lj-accent), rgba(42, 58, 51, 0.9) 22%, rgba(42, 58, 51, 0.5));
}

.page-about .about-node {
  position: relative;
  padding-left: 34px;
  padding-bottom: clamp(30px, 6vw, 56px);
}

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

.page-about .about-node__mark {
  position: absolute;
  left: 4px;
  top: 10px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--lj-soft);
  box-shadow: 0 0 0 4px rgba(0, 229, 160, 0.12);
}

.page-about .about-node--latest .about-node__mark {
  background: var(--lj-accent);
  box-shadow: 0 0 0 5px rgba(0, 229, 160, 0.2);
}

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

.page-about .about-node__yearnum {
  font-family: var(--lj-font-num);
  font-size: var(--about-year-size);
  line-height: 0.9;
  font-weight: 700;
  letter-spacing: -0.045em;
  color: var(--lj-soft);
}

.page-about .about-node--latest .about-node__yearnum {
  color: var(--lj-accent);
}

.page-about .about-node__tag {
  font-family: var(--lj-font-num);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--lj-muted);
  border-bottom: 1px solid var(--lj-line);
  padding-bottom: 2px;
}

.page-about .about-node__body h3 {
  margin: 0 0 8px;
}

.page-about .about-node__body p {
  color: var(--lj-muted);
  max-width: 64ch;
}

/* ---------- 团队 ---------- */
.page-about .about-team {
  border-top: 1px solid var(--lj-line);
}

.page-about .about-team__media {
  margin: 0 0 clamp(24px, 5vw, 0px);
}

.page-about .about-team__media .lj-media__caption {
  margin-top: 12px;
  font-size: 14px;
  line-height: 1.6;
  color: var(--lj-muted);
}

.page-about .about-team__text .lj-h2 {
  margin: 12px 0 clamp(14px, 2.4vw, 22px);
}

.page-about .about-team__text p {
  color: var(--lj-muted);
  max-width: 62ch;
}

.page-about .about-team__text p + p {
  margin-top: 14px;
}

.page-about .about-tree {
  list-style: none;
  margin: clamp(28px, 5vw, 52px) 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background-color: var(--lj-line);
  border: 1px solid var(--lj-line);
}

.page-about .about-tree__branch {
  position: relative;
  background-color: var(--lj-ink);
  padding: clamp(18px, 3vw, 26px) clamp(16px, 3vw, 28px) clamp(18px, 3vw, 26px) clamp(30px, 4vw, 40px);
  transition: background-color 0.25s var(--lj-ease);
}

.page-about .about-tree__branch::before {
  content: "";
  position: absolute;
  left: clamp(14px, 2vw, 20px);
  top: clamp(24px, 3.6vw, 34px);
  bottom: 0;
  width: 1px;
  background: rgba(42, 58, 51, 0.85);
}

.page-about .about-tree__branch:last-child::before {
  bottom: auto;
  height: clamp(24px, 3.6vw, 34px);
}

.page-about .about-tree__node {
  position: absolute;
  left: clamp(10px, 1.6vw, 16px);
  top: clamp(20px, 3.2vw, 30px);
  width: 9px;
  height: 9px;
  background: var(--lj-accent);
  transform: rotate(45deg);
}

.page-about .about-tree__branch:hover,
.page-about .about-tree__branch:focus-within {
  background-color: var(--lj-panel);
}

.page-about .about-tree__title {
  margin: 0 0 8px;
  font-family: var(--lj-font-display);
  font-size: clamp(19px, 2.4vw, 24px);
  line-height: 1.25;
  letter-spacing: 0.01em;
}

.page-about .about-tree__desc {
  margin: 0 0 12px;
  color: var(--lj-muted);
  max-width: 66ch;
}

.page-about .about-tree__tag {
  display: inline-block;
}

/* ---------- 记录方式 ---------- */
.page-about .about-method {
  border-top: 1px solid var(--lj-line);
}

.page-about .about-method__grid {
  margin-top: clamp(20px, 4vw, 36px);
}

.page-about .about-method__item {
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: clamp(20px, 3vw, 30px);
  background: var(--lj-panel);
  border: 1px solid var(--lj-line);
  border-top: 2px solid var(--lj-accent);
}

.page-about .about-method__index {
  font-family: var(--lj-font-num);
  font-size: 14px;
  letter-spacing: 0.18em;
  color: var(--lj-soft);
}

.page-about .about-method__item h3 {
  margin: 0;
}

.page-about .about-method__item p {
  margin: 0;
  color: var(--lj-muted);
}

.page-about .about-fields {
  margin-top: clamp(32px, 6vw, 56px);
}

.page-about .about-fields .lj-eyebrow {
  margin-bottom: 12px;
}

.page-about .about-field {
  border-top: 1px solid var(--lj-line);
}

.page-about .about-field:last-child {
  border-bottom: 1px solid var(--lj-line);
}

.page-about .about-field__summary {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  padding: 16px 2px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-field__summary::after {
  content: "+";
  flex: 0 0 auto;
  font-family: var(--lj-font-num);
  font-size: 20px;
  line-height: 1;
  color: var(--lj-accent);
  transition: transform 0.22s var(--lj-ease);
}

.page-about .about-field[open] .about-field__summary::after {
  transform: rotate(45deg);
}

.page-about .about-field__name {
  font-family: var(--lj-font-num);
  font-size: clamp(16px, 2vw, 18px);
  font-weight: 700;
  color: var(--lj-text);
}

.page-about .about-field__hint {
  margin-left: auto;
  padding-right: 14px;
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--lj-muted);
}

.page-about .about-field__body {
  margin: 0;
  padding: 0 2px 18px;
  color: var(--lj-muted);
  max-width: 74ch;
}

/* ---------- 服务区域 ---------- */
.page-about .about-reach {
  position: relative;
  background: var(--lj-panel);
  border-top: 1px solid var(--lj-line);
  border-bottom: 1px solid var(--lj-line);
  overflow: hidden;
}

.page-about .about-reach::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: clamp(60px, 14vw, 180px);
  height: 3px;
  background: linear-gradient(90deg, var(--lj-accent), var(--lj-warm));
}

.page-about .about-reach__inner .lj-h2 {
  margin: 12px 0 clamp(14px, 2.4vw, 20px);
}

.page-about .about-reach__inner p {
  color: var(--lj-muted);
  max-width: 60ch;
}

.page-about .about-reach__detail {
  padding-top: clamp(4px, 2vw, 0px);
}

.page-about .about-reach__detail p + p {
  margin-top: 14px;
}

.page-about .about-reach__detail .lj-meta {
  margin-top: clamp(18px, 3vw, 26px);
  color: var(--lj-soft);
}

/* ---------- 合作节奏 ---------- */
.page-about .about-promise__panel {
  position: relative;
  padding: clamp(26px, 5vw, 56px);
  background: var(--lj-panel);
  border: 1px solid var(--lj-line);
}

.page-about .about-promise__panel .lj-h2 {
  margin: 12px 0 clamp(20px, 3.4vw, 32px);
}

.page-about .about-promise__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background-color: var(--lj-line);
  border: 1px solid var(--lj-line);
}

.page-about .about-promise__item {
  display: flex;
  align-items: baseline;
  gap: clamp(14px, 3vw, 24px);
  padding: clamp(14px, 2.6vw, 20px) clamp(14px, 2.6vw, 22px);
  background-color: var(--lj-ink);
}

.page-about .about-promise__num {
  flex: 0 0 auto;
  min-width: 4.2em;
  font-family: var(--lj-font-num);
  font-size: clamp(22px, 3.4vw, 32px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.02em;
}

.page-about .about-promise__text {
  color: var(--lj-muted);
}

.page-about .about-promise__cta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(24px, 4vw, 36px);
}

.page-about .about-promise__note {
  margin: 18px 0 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--lj-muted);
}

.page-about .about-promise__link {
  color: var(--lj-accent);
  text-decoration: none;
  border-bottom: 1px solid rgba(0, 229, 160, 0.45);
}

.page-about .about-promise__link:hover,
.page-about .about-promise__link:focus-visible {
  border-bottom-color: var(--lj-accent);
}

/* ---------- 中屏 ---------- */
@media (min-width: 640px) {
  .page-about .about-figures {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

/* ---------- 桌面 ---------- */
@media (min-width: 900px) {
  .page-about {
    --about-year-size: clamp(64px, 6.6vw, 96px);
  }

  .page-about .about-hero__title {
    max-width: 22ch;
  }

  .page-about .about-start__media {
    margin-top: clamp(28px, 5vw, 56px);
  }

  .page-about .about-nodes {
    margin-top: clamp(28px, 4vw, 48px);
  }

  .page-about .about-nodes::before {
    left: 25px;
    bottom: 48px;
  }

  .page-about .about-node {
    display: grid;
    grid-template-columns: minmax(230px, 0.82fr) minmax(0, 2.18fr);
    column-gap: clamp(24px, 4vw, 56px);
    padding-left: 56px;
  }

  .page-about .about-node__mark {
    left: 20px;
    top: 22px;
  }

  .page-about .about-node__year {
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
    margin-bottom: 0;
  }

  .page-about .about-node__body {
    padding-top: 6px;
  }

  .page-about .about-node:nth-child(even) .about-node__body {
    margin-left: var(--about-shift);
  }

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

  .page-about .about-team__media {
    margin-top: clamp(12px, 2vw, 28px);
  }
}

@media (min-width: 1180px) {
  .page-about .about-node {
    padding-left: 64px;
  }

  .page-about .about-nodes::before {
    left: 29px;
  }

  .page-about .about-node__mark {
    left: 24px;
  }
}

/* ---------- 动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .about-tree__branch,
  .page-about .about-field__summary::after {
    transition: none;
  }

  .page-about .about-field[open] .about-field__summary::after {
    transform: none;
  }
}