.page-about {
  --about-pad: clamp(18px, 3.4vw, 34px);
}

.page-about .about-top {
  padding-top: clamp(20px, 3vw, 34px);
}

.page-about .about-top .breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--text-3);
}

.page-about .about-top .breadcrumb li + li::before {
  content: "/";
  margin-right: 8px;
  color: var(--line);
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  display: grid;
  gap: clamp(24px, 4vw, 44px);
  padding: clamp(20px, 3vw, 34px) var(--gutter) clamp(36px, 5vw, 62px);
  position: relative;
}

.page-about .about-hero__text .eyebrow {
  display: inline-block;
  margin: 0 0 14px;
  padding: 4px 10px;
  background: var(--cinnabar-500);
  color: #F7F4EE;
  font-size: 11px;
  letter-spacing: .14em;
}

.page-about .about-hero__text .display-title {
  margin: 0 0 18px;
}

.page-about .about-hero__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin-top: clamp(22px, 3vw, 32px);
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
}

.page-about .about-fact {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 14px 16px;
  background: var(--bg);
}

.page-about .about-fact__num {
  font-size: clamp(22px, 3vw, 30px);
  font-weight: 700;
  line-height: 1;
  color: var(--text);
}

.page-about .about-fact__label {
  font-size: 12.5px;
  letter-spacing: .04em;
  color: var(--text-3);
}

.page-about .about-hero__year {
  margin: 0;
  padding-top: 16px;
  border-top: 1px solid var(--line);
}

.page-about .about-hero__year-num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(58px, 15vw, 132px);
  font-weight: 700;
  line-height: .84;
  letter-spacing: -.01em;
  color: transparent;
  -webkit-text-stroke: 2px var(--text-3);
}

.page-about .about-hero__year-note {
  display: block;
  margin: 14px 0 0;
  font-size: 12px;
  line-height: 1.9;
  letter-spacing: .04em;
  color: var(--text-2);
}

@media (min-width: 900px) {
  .page-about .about-hero {
    grid-template-columns: minmax(0, 7fr) minmax(210px, 4fr);
    align-items: end;
    gap: clamp(34px, 5vw, 76px);
    padding-bottom: clamp(52px, 6vw, 84px);
  }

  .page-about .about-hero__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

/* ---------- 主体骨架 ---------- */

.page-about .about-body {
  padding-bottom: clamp(48px, 7vw, 96px);
}

.page-about .about-index__title {
  margin: 0 0 12px;
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--text-3);
}

.page-about .about-index .aside-note {
  margin-top: 18px;
  font-size: 12.5px;
  line-height: 1.8;
}

.page-about .about-flow {
  display: grid;
  gap: clamp(40px, 6vw, 76px);
  min-width: 0;
}

.page-about .about-block {
  min-width: 0;
  scroll-margin-top: var(--header-offset);
}

.page-about .about-block .section-head {
  margin-bottom: clamp(18px, 2.6vw, 28px);
}

.page-about .about-block .prose {
  margin: 0;
}

/* ---------- 01 平台在做什么 ---------- */

.page-about .about-pillars {
  display: grid;
  gap: 1px;
  margin: clamp(22px, 3vw, 32px) 0 0;
  padding: 0;
  list-style: none;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
}

.page-about .about-pillar {
  position: relative;
  padding: var(--about-pad);
  background: var(--bg-2);
  transition: transform 200ms var(--ease), border-color 200ms var(--ease);
}

.page-about .about-pillar:hover {
  transform: translateY(-2px);
  border-left: 2px solid var(--moss-600);
}

.page-about .about-pillar__num {
  display: inline-block;
  margin-bottom: 10px;
  padding: 2px 8px;
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--moss-ink);
  border: 1px solid currentColor;
}

.page-about .about-pillar__title {
  margin: 0 0 10px;
  font-size: 17px;
  font-weight: 600;
  line-height: 1.5;
  color: var(--text);
}

.page-about .about-pillar p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--text-2);
}

@media (min-width: 780px) {
  .page-about .about-pillars {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

/* ---------- 02 时间线 ---------- */

.page-about .about-timeline {
  display: flex;
  gap: 0;
  margin: 26px 0 0;
  padding: 14px 0 20px;
  list-style: none;
  overflow-x: auto;
  overscroll-behavior-x: contain;
  scroll-snap-type: x proximity;
}

.page-about .about-timeline__item {
  position: relative;
  flex: 0 0 clamp(216px, 70vw, 252px);
  padding: 26px 22px 0 0;
  scroll-snap-align: start;
}

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  top: 8px;
  right: 0;
  left: 0;
  height: 1px;
  background: var(--line-soft);
}

.page-about .about-timeline__dot {
  position: absolute;
  top: 4px;
  left: 0;
  z-index: 1;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--silver-300);
  box-shadow: 0 0 0 4px var(--bg);
}

.page-about .about-timeline__item--major .about-timeline__dot {
  background: var(--cinnabar-500);
  box-shadow: 0 0 0 4px var(--bg), 0 0 0 7px rgba(211, 52, 43, .18);
}

.page-about .about-timeline__year {
  display: block;
  margin: 6px 0 12px;
  font-size: 13px;
  letter-spacing: .12em;
  color: var(--text-3);
}

.page-about .about-timeline__item--major .about-timeline__year {
  color: var(--cinnabar-ink);
  font-weight: 700;
}

.page-about .about-timeline__title {
  margin: 0 0 8px;
  font-size: 15.5px;
  font-weight: 600;
  line-height: 1.5;
}

.page-about .about-timeline__title a {
  color: var(--text);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 180ms var(--ease), color 180ms var(--ease);
}

.page-about .about-timeline__title a:hover,
.page-about .about-timeline__title a:focus-visible {
  color: var(--cyan-ink);
  border-bottom-color: currentColor;
}

.page-about .about-timeline__card p {
  margin: 0 0 12px;
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--text-2);
}

/* ---------- 03 产品线 ---------- */

.page-about .about-lines {
  display: grid;
  gap: 1px;
  margin: clamp(20px, 3vw, 30px) 0 0;
  padding: 0;
  list-style: none;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
}

.page-about .about-line {
  position: relative;
  display: grid;
  grid-template-columns: 42px minmax(0, 1fr);
  gap: 4px 14px;
  padding: var(--about-pad);
  background: var(--bg);
  transition: background-color 200ms var(--ease), transform 200ms var(--ease);
}

.page-about .about-line:hover,
.page-about .about-line:focus-within {
  background: var(--bg-2);
  transform: translateY(-2px);
}

.page-about .about-line__bar {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  width: 3px;
  background: var(--line);
  transition: background-color 200ms var(--ease);
}

.page-about .about-line--nav .about-line__bar { background: #9BA6B2; }
.page-about .about-line--account .about-line__bar { background: var(--cyan-spark-400); }
.page-about .about-line--tool .about-line__bar { background: var(--clay-500); }
.page-about .about-line--index .about-line__bar { background: var(--moss-600); }

.page-about .about-line__num {
  grid-column: 1;
  align-self: start;
  padding-top: 3px;
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--text-3);
}

.page-about .about-line__main {
  grid-column: 2;
}

.page-about .about-line__name {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 600;
  color: var(--text);
}

.page-about .about-line__scope {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--text-2);
}

.page-about .about-line__when {
  grid-column: 2;
  margin: 10px 0 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--text-3);
}

@media (min-width: 880px) {
  .page-about .about-line {
    grid-template-columns: 52px minmax(0, 7fr) minmax(0, 3fr);
    align-items: start;
  }

  .page-about .about-line__main {
    grid-column: 2;
  }

  .page-about .about-line__when {
    grid-column: 3;
    margin: 3px 0 0;
    text-align: right;
  }
}

/* ---------- 04 团队 ---------- */

.page-about .about-team {
  display: grid;
  gap: clamp(22px, 3.4vw, 36px);
}

.page-about .about-team__body .prose {
  margin: 0;
}

.page-about .about-team__groups {
  display: grid;
  gap: 1px;
  margin: 24px 0 0;
  padding: 0;
  list-style: none;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
}

.page-about .about-team__group {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  align-items: baseline;
  gap: 4px 12px;
  padding: 13px 16px;
  background: var(--bg-2);
  font-size: 14px;
  line-height: 1.75;
  color: var(--text-2);
}

.page-about .about-team__group-num {
  font-size: 11.5px;
  letter-spacing: .12em;
  color: var(--moss-ink);
}

.page-about .about-team__group strong {
  color: var(--text);
  font-weight: 600;
}

.page-about .about-team__group span:last-child {
  grid-column: 2;
}

.page-about .about-team__figure {
  align-self: start;
}

@media (min-width: 900px) {
  .page-about .about-team {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    align-items: start;
  }
}

/* ---------- 05 适配与合规 ---------- */

.page-about .about-fit {
  display: grid;
  gap: clamp(22px, 3.4vw, 34px);
  margin-top: clamp(22px, 3vw, 32px);
}

.page-about .about-fit__title {
  margin: 0 0 14px;
  padding-left: 12px;
  border-left: 3px solid var(--moss-600);
  font-size: 16px;
  font-weight: 600;
  color: var(--text);
}

.page-about .about-fit__col:last-child .about-fit__title {
  border-left-color: var(--clay-500);
}

.page-about .about-fit__list {
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line-soft);
}

.page-about .about-fit__list li {
  position: relative;
  padding: 11px 0 11px 20px;
  border-bottom: 1px solid var(--line-soft);
  font-size: 14px;
  line-height: 1.75;
  color: var(--text-2);
}

.page-about .about-fit__list li::before {
  content: "";
  position: absolute;
  top: 19px;
  left: 2px;
  width: 7px;
  height: 7px;
  background: var(--moss-600);
}

.page-about .about-fit__col:last-child .about-fit__list li::before {
  background: var(--clay-500);
}

.page-about .about-fit__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-top: 16px;
}

.page-about .about-fit__note {
  margin: 16px 0 0;
  font-size: 13.5px;
  line-height: 1.8;
  color: var(--text-3);
}

@media (min-width: 820px) {
  .page-about .about-fit {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

/* ---------- 06 长期服务 ---------- */

.page-about .about-support {
  display: grid;
  gap: 1px;
  margin-top: clamp(22px, 3vw, 30px);
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
}

.page-about .about-support__card {
  position: relative;
  padding: var(--about-pad);
  background: var(--bg-2);
  transition: transform 200ms var(--ease);
}

.page-about .about-support__card:hover {
  transform: translateY(-2px);
}

.page-about .about-support__card-num {
  display: inline-block;
  margin-bottom: 10px;
  padding: 2px 8px;
  font-size: 11px;
  letter-spacing: .16em;
  border: 1px solid currentColor;
}

.page-about .about-support__card--service .about-support__card-num {
  color: var(--cyan-ink);
}

.page-about .about-support__card--version .about-support__card-num {
  color: var(--amber-ink);
}

.page-about .about-support__card--scope .about-support__card-num {
  color: var(--clay-ink);
}

.page-about .about-support__card h3 {
  margin: 0 0 10px;
  font-size: 16.5px;
  font-weight: 600;
  color: var(--text);
}

.page-about .about-support__card p {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--text-2);
}

.page-about .about-support__next {
  margin-top: clamp(20px, 2.8vw, 28px);
  padding: 16px 18px;
  border: 1px dashed var(--line);
  font-size: 14px;
  line-height: 1.85;
  color: var(--text-2);
}

.page-about .about-support__next p {
  margin: 0;
}

@media (min-width: 840px) {
  .page-about .about-support {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

/* ---------- 窄屏细节 ---------- */

@media (max-width: 560px) {
  .page-about .about-hero__year-num {
    -webkit-text-stroke-width: 1.5px;
  }

  .page-about .about-timeline__item {
    flex-basis: min(78vw, 260px);
  }

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

  .page-about .about-line__num,
  .page-about .about-line__main,
  .page-about .about-line__when {
    grid-column: 1;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-pillar,
  .page-about .about-line,
  .page-about .about-support__card {
    transition: none;
  }

  .page-about .about-pillar:hover,
  .page-about .about-line:hover,
  .page-about .about-line:focus-within,
  .page-about .about-support__card:hover {
    transform: none;
  }
}