.page-about {
  --about-rail: 168px;
  overflow-x: clip;
}

/* 阅读进度细线 */
.page-about .about-progress {
  position: fixed;
  inset-block: 0;
  right: 0;
  width: 2px;
  background: var(--grid-line);
  pointer-events: none;
  z-index: 5;
}

.page-about .about-progress__bar {
  display: block;
  width: 100%;
  height: 100%;
  background: linear-gradient(180deg, var(--cyan), var(--red));
  transform-origin: top center;
  transform: scaleY(1);
}

@keyframes about-progress-grow {
  from { transform: scaleY(0); }
  to { transform: scaleY(1); }
}

@media (prefers-reduced-motion: no-preference) {
  @supports (animation-timeline: scroll()) {
    .page-about .about-progress__bar {
      animation: about-progress-grow linear both;
      animation-timeline: scroll(root);
    }
  }
}

/* 首屏 */
.page-about .about-hero {
  position: relative;
  isolation: isolate;
  border-bottom: 1px solid var(--grid-line);
  padding-block: clamp(20px, 3vw, 36px) clamp(56px, 9vw, 116px);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background:
    radial-gradient(70% 58% at 78% 10%, rgba(22, 224, 208, .10), transparent 68%),
    radial-gradient(52% 44% at 10% 92%, rgba(198, 27, 60, .11), transparent 70%);
  pointer-events: none;
}

.page-about .about-hero__kicker {
  margin: clamp(40px, 8vw, 92px) 0 0;
  color: var(--cyan);
  font-size: 12px;
  letter-spacing: .26em;
  text-transform: uppercase;
}

.page-about .about-hero__title {
  margin: clamp(14px, 2vw, 24px) 0 0;
  font-size: clamp(38px, 8.2vw, 106px);
  font-weight: 900;
  line-height: .97;
  letter-spacing: -.035em;
  color: var(--mist);
  max-width: 14ch;
}

.page-about .about-hero__lede {
  margin: clamp(20px, 3vw, 34px) 0 0;
  max-width: 56ch;
  color: var(--silver);
  font-size: clamp(16px, 1.3vw, 19px);
  line-height: 1.8;
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(28px, 4vw, 46px);
}

/* 分段 */
.page-about .about-block {
  position: relative;
  padding-block: clamp(52px, 8vw, 110px);
}

.page-about .about-block + .about-block,
.page-about .about-block + .about-next {
  border-top: 1px solid var(--grid-line);
}

.page-about .about-block--indigo {
  background: var(--indigo);
}

.page-about .about-block--indigo::before {
  content: "";
  position: absolute;
  inset-inline: 0;
  top: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--cyan-soft), transparent);
}

/* 双栏错位网格 */
.page-about .about-block__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(18px, 3vw, 28px);
}

.page-about .about-block__rail {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 12px;
}

.page-about .about-block__num {
  color: var(--red);
  font-size: 13px;
  letter-spacing: .14em;
}

.page-about .about-block__label {
  color: var(--slate);
  font-size: 12px;
  letter-spacing: .22em;
}

.page-about .about-block__name {
  color: var(--mist);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: .06em;
}

.page-about .about-block__body {
  max-width: 68ch;
  min-width: 0;
}

.page-about .about-block__title {
  margin: 0;
  color: var(--mist);
  font-size: clamp(26px, 3.4vw, 44px);
  font-weight: 900;
  line-height: 1.14;
  letter-spacing: -.02em;
  max-width: 24ch;
}

.page-about .about-block__lede {
  margin: clamp(16px, 2vw, 26px) 0 0;
  color: var(--silver);
  font-size: clamp(16px, 1.2vw, 18px);
  line-height: 1.78;
  max-width: 60ch;
}

.page-about .about-block__prose {
  margin-top: clamp(18px, 2.4vw, 30px);
}

.page-about .about-block__note {
  margin: clamp(22px, 2.8vw, 34px) 0 0;
  padding-left: 16px;
  border-left: 2px solid var(--red);
  color: var(--silver);
  line-height: 1.78;
  max-width: 62ch;
}

/* 图片 */
.page-about .about-figure {
  margin: clamp(28px, 4vw, 46px) 0 0;
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  border: 1px solid var(--grid-line);
}

.page-about .about-figure__cap {
  display: block;
  margin-top: 10px;
  color: var(--slate);
  font-size: 12px;
  letter-spacing: .08em;
}

.page-about .about-figure--strip img {
  height: clamp(120px, 22vw, 230px);
  opacity: .88;
}

.page-about .about-figure--pan {
  margin: clamp(40px, 5vw, 72px) 0 0;
}

.page-about .about-figure--pan img {
  height: clamp(170px, 26vw, 320px);
  border-inline: none;
}

/* 三条做法 */
.page-about .about-practices {
  list-style: none;
  margin: clamp(28px, 3.8vw, 46px) 0 0;
  padding: 0;
}

.page-about .about-practice {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 8px;
  padding-block: clamp(20px, 2.6vw, 32px);
  border-top: 1px solid var(--hair);
}

.page-about .about-practice:last-child {
  border-bottom: 1px solid var(--hair);
}

.page-about .about-practice__num {
  color: var(--cyan);
  font-size: 13px;
  letter-spacing: .16em;
}

.page-about .about-practice__title {
  margin: 0;
  color: var(--mist);
  font-size: clamp(18px, 1.7vw, 22px);
  font-weight: 800;
  letter-spacing: -.01em;
}

.page-about .about-practice__content p {
  margin: 10px 0 0;
  color: var(--silver);
  line-height: 1.78;
  max-width: 62ch;
}

/* 术语条 */
.page-about .about-terms {
  list-style: none;
  margin: clamp(26px, 3.2vw, 42px) 0 0;
  padding: 0;
  display: grid;
  gap: 0;
}

.page-about .about-term {
  border-top: 1px solid var(--hair);
  padding-block: clamp(14px, 1.8vw, 20px);
}

.page-about .about-term:last-child {
  border-bottom: 1px solid var(--hair);
}

.page-about .about-term__key {
  display: block;
  color: var(--mist);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: .06em;
}

.page-about .about-term__def {
  display: block;
  margin-top: 6px;
  color: var(--slate);
  font-size: 13px;
  line-height: 1.7;
  transition: opacity .25s var(--ease), transform .25s var(--ease), color .25s var(--ease);
}

/* 时间线 */
.page-about .about-timeline {
  position: relative;
  list-style: none;
  margin: clamp(30px, 4vw, 52px) 0 0;
  padding: 0 0 0 30px;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 8px;
  bottom: 14px;
  width: 1px;
  background: linear-gradient(180deg, var(--cyan-soft), rgba(94, 142, 139, .18));
}

.page-about .about-node {
  position: relative;
  padding-bottom: clamp(24px, 3.2vw, 42px);
}

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

.page-about .about-node::before {
  content: "";
  position: absolute;
  left: -30px;
  top: 6px;
  width: 11px;
  height: 11px;
  background: var(--red);
  border-radius: var(--radius);
}

.page-about .about-node__step {
  display: block;
  color: var(--slate);
  font-size: 12px;
  letter-spacing: .18em;
}

.page-about .about-node__title {
  margin: 8px 0 0;
  color: var(--mist);
  font-size: clamp(18px, 1.8vw, 23px);
  font-weight: 800;
  letter-spacing: -.01em;
}

.page-about .about-node__text {
  margin: 10px 0 0;
  color: var(--silver);
  line-height: 1.78;
  max-width: 62ch;
}

/* 团队分组 */
.page-about .about-groups {
  list-style: none;
  margin: clamp(26px, 3.4vw, 42px) 0 0;
  padding: 0;
}

.page-about .about-group {
  display: grid;
  gap: 8px;
  padding-block: clamp(16px, 2vw, 24px);
  border-top: 1px solid var(--hair);
}

.page-about .about-group:last-child {
  border-bottom: 1px solid var(--hair);
}

.page-about .about-group__name {
  color: var(--mist);
  font-size: 16px;
  font-weight: 800;
  letter-spacing: .04em;
}

.page-about .about-group__desc {
  color: var(--silver);
  line-height: 1.75;
  max-width: 56ch;
}

/* 协作生态 */
.page-about .about-partners {
  list-style: none;
  margin: clamp(28px, 3.6vw, 44px) 0 0;
  padding: 0;
  display: grid;
  gap: clamp(20px, 3vw, 34px);
}

.page-about .about-partner {
  border-top: 1px solid var(--hair);
  padding-top: 16px;
}

.page-about .about-partner__key {
  display: block;
  color: var(--slate);
  font-size: 11px;
  letter-spacing: .24em;
}

.page-about .about-partner__name {
  display: block;
  margin-top: 6px;
  color: var(--mist);
  font-size: 17px;
  font-weight: 800;
  letter-spacing: .02em;
}

.page-about .about-partner__desc {
  margin: 10px 0 0;
  color: var(--silver);
  line-height: 1.78;
  max-width: 52ch;
}

/* 数据 */
.page-about .about-stats {
  list-style: none;
  margin: clamp(28px, 3.6vw, 44px) 0 0;
  padding: 0;
  display: grid;
  gap: 22px;
}

.page-about .about-stat {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 6px;
  padding-top: 14px;
  border-top: 1px solid var(--hair);
}

.page-about .about-stat__num {
  font-family: var(--font-mono);
  font-size: clamp(32px, 4.4vw, 52px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--mist);
}

.page-about .about-stat__unit {
  font-size: 14px;
  letter-spacing: .06em;
  color: var(--cyan);
}

.page-about .about-stat__label {
  flex-basis: 100%;
  margin-top: 6px;
  color: var(--slate);
  font-size: 13px;
  letter-spacing: .06em;
}

/* 结语区 */
.page-about .about-next {
  padding-block: clamp(56px, 8vw, 108px);
}

.page-about .about-next__eyebrow {
  margin: 0;
  color: var(--cyan);
  font-size: 12px;
  letter-spacing: .26em;
  text-transform: uppercase;
}

.page-about .about-next__title {
  margin: clamp(14px, 2vw, 22px) 0 0;
  color: var(--mist);
  font-size: clamp(24px, 3.2vw, 42px);
  font-weight: 900;
  line-height: 1.16;
  letter-spacing: -.02em;
  max-width: 22ch;
}

.page-about .about-next__text {
  margin: clamp(14px, 2vw, 22px) 0 0;
  color: var(--silver);
  line-height: 1.78;
  max-width: 58ch;
}

.page-about .about-next__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(24px, 3.4vw, 40px);
}

/* 移动端 */
@media (max-width: 899px) {
  .page-about .about-progress {
    display: none;
  }

  .page-about .about-hero__title {
    max-width: none;
  }

  .page-about .about-block__title {
    max-width: none;
  }
}

/* 桌面端双栏与错位 */
@media (min-width: 900px) {
  .page-about .about-block__grid {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: clamp(32px, 4.5vw, 76px);
  }

  .page-about .about-block__rail {
    display: block;
    padding-top: 8px;
    border-top: 1px solid var(--hair);
  }

  .page-about .about-block__num {
    display: block;
    margin-top: 10px;
  }

  .page-about .about-block__label {
    display: block;
    margin-top: 14px;
  }

  .page-about .about-block__name {
    display: block;
    margin-top: 4px;
  }

  .page-about .about-partners {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: clamp(20px, 2.6vw, 34px);
  }

  .page-about .about-term__def {
    opacity: .62;
    transform: translateX(-4px);
  }

  .page-about .about-term:hover .about-term__def,
  .page-about .about-term:focus-within .about-term__def {
    opacity: 1;
    color: var(--silver);
    transform: translateX(0);
  }
}

@media (min-width: 760px) {
  .page-about .about-practice {
    grid-template-columns: 56px minmax(0, 1fr);
    gap: 0 24px;
    align-items: start;
  }

  .page-about .about-group {
    grid-template-columns: 150px minmax(0, 1fr);
    gap: 0 28px;
    align-items: start;
  }

  .page-about .about-stats {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 28px;
  }
}

@media (min-width: 1180px) {
  .page-about .about-block--offset .about-block__grid {
    padding-left: clamp(0px, 3.6vw, 56px);
  }
}