.page-about {
  --about-gap: clamp(28px, 5vw, 64px);
  --about-band: linear-gradient(90deg, var(--signal), rgba(255,106,42,0));
  display: block;
  background: var(--ink);
  color: var(--mist);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(28px, 6vw, 64px) 0 clamp(36px, 6vw, 72px);
  background:
    radial-gradient(120% 80% at 80% -10%, rgba(70, 216, 199, .16), transparent 60%),
    linear-gradient(180deg, var(--ink) 0%, var(--forest) 78%, var(--ink) 100%);
}

.page-about .about-hero__bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  pointer-events: none;
}

.page-about .about-hero__bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: .2;
  filter: grayscale(.35) contrast(1.1);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 0;
  background:
    linear-gradient(180deg, rgba(8,12,11,.55), rgba(8,12,11,.92) 70%),
    repeating-linear-gradient(90deg, transparent 0 79px, rgba(142,165,157,.07) 79px 80px);
  pointer-events: none;
}

.page-about .about-hero__inner {
  position: relative;
  z-index: 1;
}

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

.page-about .about-hero__title {
  font-family: var(--font-display);
  font-size: clamp(2rem, 8vw, 4.4rem);
  line-height: 1.06;
  letter-spacing: -.02em;
  margin: 14px 0 0;
  max-width: 18ch;
  color: var(--paper);
}

.page-about .about-hero__lede {
  margin: clamp(18px, 3vw, 28px) 0 0;
  max-width: 60ch;
  font-size: clamp(1rem, 2.2vw, 1.125rem);
  line-height: 1.8;
  color: rgba(241, 245, 242, .86);
}

.page-about .about-meters {
  list-style: none;
  margin: clamp(32px, 5vw, 56px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 2px;
  background: var(--line-soft);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.page-about .about-meter {
  background: var(--teal);
  padding: 16px 16px 18px;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 4px;
  position: relative;
  transition: background .25s var(--ease);
}

.page-about .about-meter::before {
  content: "";
  position: absolute;
  left: 0;
  top: 16px;
  bottom: 16px;
  width: 3px;
  border-radius: var(--pill);
  background: var(--cold);
  opacity: .8;
}

.page-about .about-meter:hover {
  background: var(--stand);
}

.page-about .about-meter__num {
  font-size: clamp(1.5rem, 5vw, 2rem);
  color: var(--paper);
  line-height: 1;
}

.page-about .about-meter__unit {
  font-size: .8125rem;
  color: var(--cold);
}

.page-about .about-meter__label {
  flex-basis: 100%;
  font-size: .8125rem;
  color: var(--steel);
  line-height: 1.5;
}

/* ---------- 章节骨架 ---------- */
.page-about .about-chapter {
  position: relative;
  padding: clamp(44px, 7vw, 88px) 0;
  border-top: 1px solid var(--line-soft);
}

.page-about .about-chapter::before {
  content: "";
  position: absolute;
  top: -1px;
  left: max(18px, calc((100vw - 1180px) / 2));
  width: clamp(48px, 12vw, 96px);
  height: 3px;
  border-radius: var(--pill);
  background: var(--about-band);
}

.page-about .about-chapter__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 3vw, 36px);
}

.page-about .about-chapter__head {
  display: flex;
  align-items: flex-start;
  gap: 14px;
}

.page-about .about-chapter__num {
  font-size: clamp(2.75rem, 11vw, 5rem);
  line-height: .82;
  color: transparent;
  -webkit-text-stroke: 1.5px rgba(255, 106, 42, .7);
  letter-spacing: -.04em;
  flex: 0 0 auto;
}

.page-about .about-chapter__title {
  font-family: var(--font-display);
  font-size: clamp(1.35rem, 4.6vw, 2.1rem);
  line-height: 1.24;
  letter-spacing: -.01em;
  color: var(--paper);
  margin: 0;
  align-self: center;
}

.page-about .about-chapter__body > p {
  margin: 0 0 16px;
  font-size: 1rem;
  line-height: 1.8;
  color: rgba(241, 245, 242, .82);
  max-width: 68ch;
}

.page-about .about-chapter__body .about-lead {
  font-size: clamp(1.0625rem, 2.4vw, 1.25rem);
  line-height: 1.7;
  color: var(--mist);
  margin-bottom: 22px;
}

/* ---------- 三条业务线 ---------- */
.page-about .about-lines {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin: 8px 0 26px;
}

.page-about .about-line {
  background: var(--teal);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-lg);
  padding: clamp(20px, 4vw, 28px);
  transition: transform .3s var(--ease), border-color .3s var(--ease), background .3s var(--ease);
}

.page-about .about-line:hover {
  transform: translateY(-2px);
  border-color: var(--line-strong);
  background: var(--stand);
}

.page-about .about-line__title {
  font-family: var(--font-display);
  font-size: clamp(1.125rem, 3.4vw, 1.4rem);
  margin: 14px 0 10px;
  color: var(--paper);
}

.page-about .about-line__text {
  margin: 0;
  font-size: .9375rem;
  line-height: 1.8;
  color: rgba(241, 245, 242, .78);
}

.page-about .about-line__meta {
  margin: 16px 0 0;
  padding-top: 14px;
  border-top: 1px dashed var(--line);
  font-size: .75rem;
  letter-spacing: .02em;
  color: var(--cold);
}

.page-about .about-links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 24px 0 0;
}

/* ---------- 内容生产 ---------- */
.page-about .about-figure {
  margin: 0 0 clamp(24px, 4vw, 36px);
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--line-soft);
  background: var(--stand);
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  aspect-ratio: 3 / 2;
}

.page-about .about-figure figcaption {
  display: block;
  padding: 12px 16px;
  font-size: .75rem;
  color: var(--steel);
  border-top: 1px solid var(--line-soft);
}

.page-about .about-flow {
  list-style: none;
  margin: 0 0 clamp(24px, 4vw, 34px);
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
  counter-reset: flow;
}

.page-about .about-flow__step {
  position: relative;
  padding: 18px 18px 18px 54px;
  border-radius: var(--radius-md);
  background: linear-gradient(90deg, rgba(22,61,50,.9), rgba(18,63,57,.55));
  border-left: 3px solid var(--signal);
}

.page-about .about-flow__idx {
  position: absolute;
  left: 18px;
  top: 18px;
  font-size: .875rem;
  color: var(--signal);
}

.page-about .about-flow__name {
  margin: 0 0 6px;
  font-size: 1rem;
  font-family: var(--font-display);
  color: var(--paper);
  letter-spacing: .01em;
}

.page-about .about-flow__step p {
  margin: 0;
  font-size: .9375rem;
  line-height: 1.75;
  color: rgba(241, 245, 242, .76);
}

.page-about .about-cadence {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line-soft);
  border-radius: var(--radius-md);
  overflow: hidden;
}

.page-about .about-cadence__item {
  display: flex;
  flex-wrap: wrap;
  gap: 6px 14px;
  padding: 14px 18px;
  background: var(--forest);
}

.page-about .about-cadence__key {
  flex: 0 0 auto;
  font-size: .75rem;
  color: var(--cold);
  letter-spacing: .06em;
  min-width: 60px;
  padding-top: 2px;
}

.page-about .about-cadence__val {
  font-size: .9375rem;
  line-height: 1.65;
  color: var(--mist);
}

/* ---------- 团队 ---------- */
.page-about .about-team {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 4vw, 32px);
  align-items: start;
}

.page-about .about-roles {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .about-role {
  background: var(--teal);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-md);
  transition: border-color .25s var(--ease), background .25s var(--ease);
}

.page-about .about-role[open] {
  background: var(--stand);
  border-color: var(--line-strong);
}

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

.page-about .about-role__summary {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px 18px;
  cursor: pointer;
  list-style: none;
  min-height: 44px;
}

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

.page-about .about-role__num {
  font-size: clamp(1.25rem, 4vw, 1.6rem);
  color: var(--signal);
  line-height: 1;
  min-width: 2.2ch;
}

.page-about .about-role__name {
  font-family: var(--font-display);
  font-size: 1rem;
  color: var(--paper);
}

.page-about .about-role__hint {
  margin-left: auto;
  font-size: .6875rem;
  color: var(--steel);
  letter-spacing: .08em;
}

.page-about .about-role[open] .about-role__hint {
  color: var(--cold);
}

.page-about .about-role__text {
  margin: 0;
  padding: 0 18px 18px;
  font-size: .9375rem;
  line-height: 1.75;
  color: rgba(241, 245, 242, .8);
}

.page-about .about-team__figure {
  margin: 0;
  border-radius: var(--radius-lg);
  overflow: hidden;
  border: 1px solid var(--line-soft);
  background: var(--stand);
}

.page-about .about-team__figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 100%;
  object-fit: cover;
  aspect-ratio: 4 / 3;
}

.page-about .about-team__figure figcaption {
  display: block;
  padding: 12px 16px;
  font-size: .75rem;
  color: var(--steel);
  border-top: 1px solid var(--line-soft);
}

/* ---------- 时间轴 ---------- */
.page-about .about-chapter--timeline {
  background:
    linear-gradient(180deg, var(--ink), var(--forest) 40%, var(--ink));
}

.page-about .about-timeline {
  list-style: none;
  margin: 8px 0 0;
  padding: 0 0 0 26px;
  position: relative;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  border-radius: var(--pill);
  background: linear-gradient(180deg, var(--signal), rgba(70,216,199,.55) 55%, rgba(142,165,157,.2));
}

.page-about .about-timeline__item {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 6px;
  padding: 0 0 clamp(22px, 4vw, 30px);
}

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

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: -26px;
  top: 10px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--ink);
  border: 2px solid var(--steel);
  transition: border-color .25s var(--ease), box-shadow .25s var(--ease);
}

.page-about .about-timeline__item:hover::before {
  border-color: var(--signal);
  box-shadow: 0 0 0 4px rgba(255, 106, 42, .16);
}

.page-about .about-timeline__year {
  font-size: clamp(1.75rem, 7vw, 2.75rem);
  line-height: 1;
  color: var(--steel);
  letter-spacing: -.02em;
  transition: color .25s var(--ease);
}

.page-about .about-timeline__item:hover .about-timeline__year {
  color: var(--signal);
}

.page-about .about-timeline__name {
  margin: 0 0 6px;
  font-family: var(--font-display);
  font-size: clamp(1rem, 2.6vw, 1.1875rem);
  color: var(--paper);
}

.page-about .about-timeline__content p {
  margin: 0;
  font-size: .9375rem;
  line-height: 1.75;
  color: rgba(241, 245, 242, .76);
  max-width: 60ch;
}

/* ---------- 生态 ---------- */
.page-about .about-eco {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
  margin: 8px 0 clamp(22px, 4vw, 32px);
}

.page-about .about-eco__card {
  padding: 20px;
  border-radius: var(--radius-lg);
  background: var(--teal);
  border: 1px solid var(--line-soft);
  position: relative;
  overflow: hidden;
  transition: border-color .25s var(--ease);
}

.page-about .about-eco__card:hover {
  border-color: var(--cold);
}

.page-about .about-eco__num {
  display: block;
  font-size: clamp(1.75rem, 6vw, 2.25rem);
  line-height: 1;
  color: var(--ember);
}

.page-about .about-eco__name {
  margin: 10px 0 8px;
  font-size: .9375rem;
  font-family: var(--font-display);
  color: var(--paper);
}

.page-about .about-eco__card p {
  margin: 0;
  font-size: .875rem;
  line-height: 1.7;
  color: rgba(241, 245, 242, .74);
}

.page-about .about-observer {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 20px;
  padding: clamp(22px, 4vw, 32px);
  border-radius: var(--radius-xl);
  background:
    radial-gradient(90% 120% at 100% 0%, rgba(70,216,199,.14), transparent 62%),
    linear-gradient(140deg, var(--stand), var(--teal));
  border: 1px solid var(--line);
}

.page-about .about-observer__title {
  margin: 12px 0 10px;
  font-family: var(--font-display);
  font-size: clamp(1.25rem, 4vw, 1.75rem);
  color: var(--paper);
}

.page-about .about-observer__main p {
  margin: 0;
  font-size: .9375rem;
  line-height: 1.8;
  color: rgba(241, 245, 242, .8);
  max-width: 56ch;
}

.page-about .about-observer__aside {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 14px;
  padding-top: 18px;
  border-top: 1px solid var(--line);
}

.page-about .about-observer__line {
  margin: 0;
  font-size: .875rem;
  line-height: 1.7;
  color: var(--steel);
}

/* ---------- 平板与桌面 ---------- */
@media (min-width: 720px) {
  .page-about .about-meters {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-lines {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 16px;
  }

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

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

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

  .page-about .about-flow__step {
    padding: 22px 18px 22px 18px;
  }

  .page-about .about-flow__idx {
    position: static;
    display: block;
    margin-bottom: 10px;
  }

  .page-about .about-timeline__item {
    grid-template-columns: minmax(0, 0.32fr) minmax(0, 1fr);
    gap: clamp(16px, 3vw, 32px);
    align-items: start;
  }

  .page-about .about-observer {
    grid-template-columns: minmax(0, 1.5fr) minmax(0, 0.8fr);
    align-items: start;
  }

  .page-about .about-observer__aside {
    padding-top: 0;
    padding-left: 20px;
    border-top: 0;
    border-left: 1px solid var(--line);
    align-self: stretch;
    justify-content: center;
  }
}

@media (min-width: 1000px) {
  .page-about .about-chapter__grid {
    grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.6fr);
    gap: clamp(32px, 5vw, 72px);
    align-items: start;
  }

  .page-about .about-chapter__head {
    position: sticky;
    top: 32px;
    display: block;
  }

  .page-about .about-chapter__num {
    display: block;
    margin-bottom: 18px;
    font-size: clamp(4.5rem, 9vw, 8rem);
  }

  .page-about .about-chapter__title {
    font-size: clamp(1.5rem, 2.4vw, 2rem);
    max-width: 16ch;
  }

  .page-about .about-team {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    gap: 32px;
  }

  .page-about .about-hero__lede {
    max-width: 52ch;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-line,
  .page-about .about-timeline__year,
  .page-about .about-timeline__item::before,
  .page-about .about-meter {
    transition: none;
  }

  .page-about .about-line:hover {
    transform: none;
  }
}