.page-about {
  --about-rail: 96px;
  --about-gap: 40px;
  padding-bottom: 104px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  display: grid;
  grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.92fr);
  gap: 48px;
  align-items: start;
  margin-top: 36px;
  padding-bottom: 36px;
}

.page-about .about-hero__kicker {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  margin: 0 0 20px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--gray);
  text-transform: uppercase;
}

.page-about .about-dot {
  width: 8px;
  height: 8px;
  background: var(--cyan);
  border-radius: 50%;
  animation: about-pulse 1.8s var(--ease) infinite;
}

@keyframes about-pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.3; }
}

.page-about .about-hero h1 {
  margin: 0 0 22px;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(30px, 4.4vw, 54px);
  line-height: 1.14;
  letter-spacing: -0.01em;
  color: var(--white);
}

.page-about .about-hero__lead {
  margin: 0 0 28px;
  max-width: 56ch;
  font-size: 17px;
  line-height: 1.78;
  color: var(--text);
}

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

.page-about .about-hero__figure {
  margin: 0;
  border: 2px solid var(--line-2);
  box-shadow: var(--hard);
  background: var(--bg-2);
}

/* ---------- 关键数字带 ---------- */
.page-about .about-figures {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 0;
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.page-about .about-figures__item {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 22px 20px;
  border-left: 1px solid var(--line);
}

.page-about .about-figures__item:first-child {
  border-left: 0;
}

.page-about .about-figures__num {
  font-family: var(--font-mono);
  font-size: 26px;
  font-weight: 700;
  color: var(--cyan);
  letter-spacing: 0.02em;
}

.page-about .about-figures__label {
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--gray);
}

/* ---------- 章节骨架 ---------- */
.page-about .about-flow {
  position: relative;
}

.page-about .about-flow::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: calc(var(--about-rail) / 2);
  width: 1px;
  background: linear-gradient(180deg, rgba(43, 233, 198, 0) 0%, var(--line-2) 6%, var(--line-2) 94%, rgba(43, 233, 198, 0) 100%);
}

.page-about .about-chapter {
  display: grid;
  grid-template-columns: var(--about-rail) minmax(0, 1fr);
  gap: var(--about-gap);
  padding: 76px 0 8px;
}

.page-about .about-chapter__rail {
  position: relative;
}

.page-about .about-chapter__num {
  position: sticky;
  top: calc(var(--header-h) + 28px);
  display: block;
  width: calc(var(--about-rail) - 22px);
  padding: 8px 0;
  text-align: center;
  font-family: var(--font-mono);
  font-size: 20px;
  font-weight: 700;
  color: var(--cyan);
  background: var(--bg);
  border: 2px solid var(--line-2);
}

.page-about .about-chapter__body {
  min-width: 0;
  padding-bottom: 52px;
}

.page-about .about-chapter__title {
  margin: 0 0 14px;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(24px, 2.6vw, 34px);
  line-height: 1.25;
  color: var(--white);
}

.page-about .about-chapter__lead {
  margin: 0 0 32px;
  max-width: 62ch;
  font-size: 16px;
  line-height: 1.78;
  color: var(--gray);
}

/* ---------- 01 用户群 ---------- */
.page-about .about-audience {
  gap: 16px;
}

.page-about .about-audience__card {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 24px 22px 26px;
  background: var(--bg-2);
}

.page-about .about-audience__card p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--text);
}

.page-about .about-audience__tag {
  margin-bottom: 2px;
}

.page-about .about-audience__title {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 19px;
  line-height: 1.4;
  color: var(--white);
}

.page-about .about-audience__point {
  margin-top: auto;
  padding-top: 12px;
  border-top: 1px dashed var(--line-2);
  font-size: 13px;
  color: var(--cyan);
  line-height: 1.6;
}

/* ---------- 02 时间轴 ---------- */
.page-about .about-timeline {
  overflow-x: auto;
  overflow-y: hidden;
  padding-bottom: 10px;
  scrollbar-width: thin;
}

.page-about .about-timeline:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 4px;
}

.page-about .about-timeline__track {
  display: flex;
  gap: 14px;
  list-style: none;
  margin: 0;
  padding: 0 4px 18px;
  min-width: min-content;
}

.page-about .about-timeline__item {
  position: relative;
  flex: 0 0 268px;
  padding: 30px 20px 24px;
  background: var(--bg-2);
  border: 2px solid var(--line);
  transition: border-color 0.25s var(--ease), transform 0.25s var(--ease);
}

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  top: 0;
  left: 20px;
  right: 20px;
  height: 3px;
  background: var(--cyan);
}

.page-about .about-timeline__item:hover,
.page-about .about-timeline__item:focus-within {
  border-color: var(--cyan);
  transform: translateY(-2px);
}

.page-about .about-timeline__year {
  display: block;
  margin-bottom: 12px;
  font-family: var(--font-mono);
  font-size: 22px;
  font-weight: 700;
  color: var(--cyan);
}

.page-about .about-timeline__title {
  margin: 0 0 10px;
  font-family: var(--font-head);
  font-size: 17px;
  font-weight: 700;
  line-height: 1.4;
  color: var(--white);
}

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

/* ---------- 03 团队 ---------- */
.page-about .about-team__figure {
  margin: 0 0 28px;
  border: 2px solid var(--line);
  background: var(--bg-3);
}

.page-about .about-roles {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 14px;
}

.page-about .about-role {
  padding: 22px 20px 24px;
  background: var(--bg-2);
  border: 2px solid var(--line);
  box-shadow: 4px 4px 0 rgba(0, 0, 0, 0.35);
  transition: border-color 0.25s var(--ease);
}

.page-about .about-role:hover {
  border-color: var(--cyan);
}

.page-about .about-role__title {
  margin: 0 0 10px;
  padding-left: 12px;
  border-left: 3px solid var(--violet);
  font-family: var(--font-head);
  font-size: 17px;
  font-weight: 700;
  line-height: 1.4;
  color: var(--white);
}

.page-about .about-role p {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--text);
}

.page-about .about-rhythm {
  margin-top: 30px;
  padding: 26px 24px 24px;
  background: var(--bg-3);
  border: 2px solid var(--line-2);
}

.page-about .about-rhythm__title {
  margin: 0 0 18px;
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--orange);
}

.page-about .about-rhythm__list {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 18px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-rhythm__list li {
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding-top: 14px;
  border-top: 2px solid var(--line);
}

.page-about .about-rhythm__time {
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 700;
  color: var(--cyan);
}

.page-about .about-rhythm__text {
  font-size: 13px;
  line-height: 1.7;
  color: var(--gray);
}

/* ---------- 04 合作生态 ---------- */
.page-about .about-eco {
  display: grid;
  grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.15fr);
  gap: 32px;
  align-items: start;
}

.page-about .about-eco__figure {
  margin: 0;
  border: 2px solid var(--line-2);
  background: var(--bg-2);
}

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

.page-about .about-eco__list li {
  padding: 20px 0 20px 20px;
  border-left: 3px solid var(--line);
  border-bottom: 1px solid var(--line);
  transition: border-color 0.25s var(--ease);
}

.page-about .about-eco__list li:first-child {
  padding-top: 4px;
}

.page-about .about-eco__list li:hover {
  border-left-color: var(--cyan);
}

.page-about .about-eco__list h3 {
  margin: 0 0 8px;
  font-family: var(--font-head);
  font-size: 18px;
  font-weight: 700;
  line-height: 1.4;
  color: var(--white);
}

.page-about .about-eco__list p {
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--text);
}

/* ---------- 05 运营信息 ---------- */
.page-about .about-facts {
  margin: 0 0 30px;
  border-top: 2px solid var(--line-2);
}

.page-about .about-facts__row {
  display: grid;
  grid-template-columns: 140px minmax(0, 1fr);
  gap: 20px;
  padding: 16px 4px;
  border-bottom: 1px solid var(--line);
}

.page-about .about-facts dt {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--gray);
}

.page-about .about-facts dd {
  margin: 0;
  font-size: 16px;
  line-height: 1.7;
  color: var(--white);
}

.page-about .about-facts dd a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(43, 233, 198, 0.4);
}

.page-about .about-facts dd a:hover {
  border-bottom-color: var(--cyan);
}

.page-about .about-outro {
  margin: 0 0 22px;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--gray);
}

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

/* ---------- 响应式 ---------- */
@media (max-width: 1000px) {
  .page-about .about-hero {
    grid-template-columns: minmax(0, 1fr);
    gap: 30px;
  }

  .page-about .about-eco {
    grid-template-columns: minmax(0, 1fr);
    gap: 24px;
  }

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

@media (max-width: 900px) {
  .page-about {
    --about-rail: 60px;
    --about-gap: 20px;
  }

  .page-about .about-flow::before {
    left: calc(var(--about-rail) / 2);
  }

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

  .page-about .about-chapter__num {
    font-size: 16px;
    padding: 6px 0;
  }

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

  .page-about .about-figures__item:nth-child(3) {
    border-left: 0;
  }

  .page-about .about-figures__item:nth-child(n + 3) {
    border-top: 1px solid var(--line);
  }

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

@media (max-width: 620px) {
  .page-about .about-hero {
    margin-top: 24px;
  }

  .page-about .about-facts__row {
    grid-template-columns: minmax(0, 1fr);
    gap: 6px;
  }

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

  .page-about .about-timeline__item {
    flex: 0 0 78%;
  }

  .page-about .about-hero__actions .btn,
  .page-about .about-outro__actions .btn {
    flex: 1 1 100%;
    text-align: center;
  }
}