.page-about {
  --about-cut: 14px;
  --about-cut-sm: 8px;
  --about-rail: 120px;
  background: var(--paper);
  color: var(--ink-900);
  overflow-x: hidden;
}

.page-about img {
  display: block;
  max-width: 100%;
  height: auto;
}

/* ---------- 切角工具 ---------- */
.page-about .about-cut {
  clip-path: polygon(
    var(--about-cut) 0,
    100% 0,
    100% calc(100% - var(--about-cut)),
    calc(100% - var(--about-cut)) 100%,
    0 100%,
    0 var(--about-cut)
  );
}

.page-about .about-cut-sm {
  clip-path: polygon(
    var(--about-cut-sm) 0,
    100% 0,
    100% calc(100% - var(--about-cut-sm)),
    calc(100% - var(--about-cut-sm)) 100%,
    0 100%,
    0 var(--about-cut-sm)
  );
}

/* ---------- 面包屑 ---------- */
.page-about .crumbs {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--mist-500);
  margin-bottom: clamp(22px, 3vw, 36px);
}

.page-about .crumbs a {
  color: var(--ink-500);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color .2s ease;
}

.page-about .crumbs a:hover {
  border-bottom-color: var(--amber-500);
}

.page-about .crumbs__sep {
  color: var(--mist-200);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: clamp(20px, 3vw, 32px) 0 clamp(48px, 6.4vw, 86px);
  background: linear-gradient(180deg, var(--mist-050) 0%, var(--paper) 84%);
  overflow: hidden;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  top: 0;
  right: -40px;
  width: 280px;
  height: 100%;
  background: repeating-linear-gradient(
    115deg,
    transparent 0 22px,
    var(--mist-200) 22px 23px
  );
  opacity: .5;
  pointer-events: none;
}

.page-about .about-hero__grid {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(28px, 4vw, 54px);
}

.page-about .about-hero__lead h1 {
  margin: 10px 0 0;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(30px, 5.2vw, 54px);
  line-height: 1.16;
  letter-spacing: -0.02em;
  color: var(--ink-900);
}

.page-about .about-hero__lede {
  margin: 20px 0 0;
  max-width: 46em;
  font-size: clamp(16px, 1.6vw, 18px);
  line-height: 1.9;
  color: var(--ink-700);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.page-about .about-hero__facts {
  background: var(--ink-900);
  color: var(--paper);
  padding: clamp(22px, 3vw, 32px);
}

.page-about .about-facts__title {
  margin: 0 0 6px;
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--amber-500);
}

.page-about .about-fact {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 13px 0;
  border-top: 1px solid rgba(252, 251, 248, .16);
}

.page-about .about-fact__num {
  flex: 0 0 auto;
  min-width: 3.4em;
  font-family: var(--font-mono);
  font-size: clamp(21px, 2.6vw, 27px);
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--amber-500);
  line-height: 1;
}

.page-about .about-fact__label {
  font-size: 14px;
  line-height: 1.6;
  color: var(--mist-200);
}

/* ---------- 区块 ---------- */
.page-about .about-sec {
  position: relative;
  padding: clamp(52px, 7vw, 96px) 0;
}

.page-about .about-sec--paper {
  background: var(--paper);
}

.page-about .about-sec--mist {
  background: var(--mist-050);
}

.page-about .about-sec--ink {
  background: var(--ink-900);
  color: var(--paper);
}

.page-about .about-sec--last {
  padding-bottom: clamp(60px, 8vw, 104px);
}

/* ---------- 区块标题 ---------- */
.page-about .about-head {
  display: grid;
  gap: 8px;
  max-width: 60ch;
  margin-bottom: clamp(28px, 4vw, 46px);
}

.page-about .about-head__num {
  font-family: var(--font-mono);
  font-size: 13px;
  font-weight: 700;
  letter-spacing: .16em;
  color: var(--amber-500);
}

.page-about .about-head__title {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(24px, 3.4vw, 36px);
  line-height: 1.24;
  letter-spacing: -0.015em;
  color: var(--ink-900);
}

.page-about .about-head__sub {
  margin: 2px 0 0;
  font-size: 16px;
  line-height: 1.85;
  color: var(--mist-500);
}

.page-about .about-head--invert .about-head__title {
  color: var(--paper);
}

.page-about .about-head--invert .about-head__sub {
  color: var(--mist-200);
}

/* ---------- 三类价值 ---------- */
.page-about .about-values {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
}

.page-about .about-value {
  background: var(--paper);
  border: 1px solid var(--mist-200);
  border-top: 3px solid var(--amber-500);
  padding: clamp(20px, 2.6vw, 28px);
}

.page-about .about-value__tag {
  margin: 0 0 12px;
  padding-left: 14px;
  position: relative;
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--ink-500);
}

.page-about .about-value__tag::before {
  content: "";
  position: absolute;
  left: 0;
  top: .55em;
  width: 8px;
  height: 2px;
  background: var(--amber-500);
}

.page-about .about-value h3 {
  margin: 0 0 10px;
  font-size: 18px;
  line-height: 1.45;
  font-weight: 700;
  color: var(--ink-900);
}

.page-about .about-value p {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--ink-700);
}

/* ---------- 图片容器 ---------- */
.page-about .about-media {
  margin: 0 0 clamp(28px, 4vw, 44px);
  background: var(--mist-050);
  border: 1px solid var(--mist-200);
  overflow: hidden;
}

.page-about .about-media img {
  width: 100%;
  object-fit: cover;
}

.page-about .about-media--wide img {
  aspect-ratio: 7 / 4;
}

.page-about .about-media--half {
  max-width: 860px;
}

.page-about .about-media--half img {
  aspect-ratio: 3 / 2;
}

.page-about .about-media--square img {
  aspect-ratio: 12 / 7;
}

.page-about .about-media .media__caption {
  padding: 12px 16px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--mist-500);
  border-top: 1px solid var(--mist-200);
  background: var(--paper);
}

/* ---------- 时间轴 ---------- */
.page-about .about-timeline {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 16px;
}

.page-about .about-timeline__item {
  display: grid;
  grid-template-columns: 1fr;
  gap: 8px;
}

.page-about .about-timeline__marker {
  position: relative;
  font-family: var(--font-mono);
}

.page-about .about-timeline__year {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 700;
  letter-spacing: .06em;
  color: var(--amber-500);
}

.page-about .about-timeline__card {
  background: var(--paper);
  border: 1px solid var(--mist-200);
  padding: clamp(18px, 2.4vw, 26px);
}

.page-about .about-timeline__card h3 {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 700;
  line-height: 1.5;
  color: var(--ink-900);
}

.page-about .about-timeline__card p {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--ink-700);
}

.page-about .about-timeline__card--now {
  background: var(--ink-900);
  border-color: var(--ink-700);
}

.page-about .about-timeline__card--now h3 {
  color: var(--paper);
}

.page-about .about-timeline__card--now p {
  color: var(--mist-200);
}

/* ---------- 折线图 ---------- */
.page-about .about-chart {
  margin-top: clamp(28px, 4vw, 46px);
  padding: clamp(20px, 3vw, 32px);
  background: var(--paper);
  border: 1px solid var(--mist-200);
}

.page-about .about-chart__cap {
  margin: 0 0 16px;
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--mist-500);
}

.page-about .about-chart svg {
  display: block;
  width: 100%;
  height: auto;
}

.page-about .about-chart text {
  font-family: var(--font-mono);
}

/* ---------- 团队 ---------- */
.page-about .about-crew {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

.page-about .about-crew__item {
  background: var(--paper);
  border: 1px solid var(--mist-200);
  border-left: 3px solid var(--mist-200);
  padding: clamp(18px, 2.4vw, 26px);
  transition: transform .22s ease, border-left-color .22s ease, background-color .22s ease;
}

.page-about .about-crew__item:hover {
  transform: translateY(-3px);
  border-left-color: var(--amber-500);
  background: var(--mist-050);
}

.page-about .about-crew__idx {
  display: block;
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--mist-500);
}

.page-about .about-crew__count {
  display: block;
  margin: 10px 0 4px;
  font-family: var(--font-mono);
  font-size: clamp(30px, 4vw, 42px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--amber-500);
}

.page-about .about-crew__item h3 {
  margin: 0 0 8px;
  font-size: 16.5px;
  font-weight: 700;
  color: var(--ink-900);
}

.page-about .about-crew__item p {
  margin: 0;
  font-size: 15px;
  line-height: 1.82;
  color: var(--ink-700);
}

/* ---------- 选题来源 ---------- */
.page-about .about-sources {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

.page-about .about-source {
  border-top: 1px solid rgba(252, 251, 248, .22);
  padding-top: 20px;
}

.page-about .about-source__no {
  display: block;
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--amber-500);
  margin-bottom: 10px;
}

.page-about .about-source h3 {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .about-source p {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--mist-200);
}

.page-about .about-cadence {
  margin-top: clamp(26px, 4vw, 44px);
  background: var(--ink-700);
  border-left: 4px solid var(--amber-500);
  padding: clamp(22px, 3vw, 34px);
}

.page-about .about-cadence__lead {
  margin: 0 0 14px;
  font-size: 16px;
  font-weight: 700;
  color: var(--paper);
}

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

.page-about .about-cadence__list li {
  position: relative;
  padding-left: 20px;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--mist-200);
}

.page-about .about-cadence__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .78em;
  width: 10px;
  height: 1px;
  background: var(--amber-500);
}

/* ---------- 双主线 ---------- */
.page-about .about-lines {
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}

.page-about .about-line {
  background: var(--paper);
  border: 1px solid var(--mist-200);
  padding: clamp(22px, 3vw, 32px);
  display: flex;
  flex-direction: column;
}

.page-about .about-line--solutions {
  border-top: 4px solid var(--ink-700);
}

.page-about .about-line--help {
  border-top: 4px solid var(--amber-500);
}

.page-about .about-line__idx {
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--mist-500);
}

.page-about .about-line h3 {
  margin: 12px 0 12px;
  font-size: clamp(20px, 2.4vw, 25px);
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--ink-900);
}

.page-about .about-line p {
  margin: 0 0 14px;
  font-size: 15.5px;
  line-height: 1.9;
  color: var(--ink-700);
}

.page-about .about-line__stat {
  font-size: 14px;
  color: var(--mist-500);
}

.page-about .about-line__stat .mono {
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--ink-900);
}

.page-about .about-line .btn {
  margin-top: auto;
  align-self: flex-start;
}

.page-about .about-bridge {
  margin-top: 24px;
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  align-items: start;
  background: var(--amber-200);
  border-left: 4px solid var(--amber-500);
  padding: clamp(22px, 3vw, 32px);
}

.page-about .about-bridge__tag {
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--ink-700);
}

.page-about .about-bridge__body h3 {
  margin: 0 0 10px;
  font-size: 18px;
  font-weight: 800;
  color: var(--ink-900);
}

.page-about .about-bridge__body p {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.9;
  color: var(--ink-700);
}

.page-about .about-bridge__link {
  justify-self: start;
  align-self: center;
  font-size: 14px;
  font-weight: 700;
  color: var(--ink-900);
  text-decoration: none;
  border-bottom: 2px solid var(--amber-500);
  padding-bottom: 2px;
  transition: color .2s ease;
}

.page-about .about-bridge__link:hover {
  color: var(--ink-500);
}

/* ---------- 服务覆盖 ---------- */
.page-about .about-reach {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(24px, 3.5vw, 44px);
}

.page-about .about-reach__lead {
  margin: 0 0 22px;
  font-size: clamp(16px, 1.7vw, 18px);
  line-height: 1.9;
  color: var(--ink-700);
}

.page-about .about-reach__lead strong {
  font-family: var(--font-mono);
  font-size: 1.15em;
  color: var(--ink-900);
}

.page-about .about-reach__list {
  list-style: none;
  margin: 0 0 22px;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .about-reach__list li {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px;
  padding: 12px 0;
  border-top: 1px solid var(--mist-200);
  font-size: 15px;
  line-height: 1.7;
  color: var(--ink-700);
}

.page-about .about-reach__list .mono {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--ink-900);
}

.page-about .about-reach__note {
  margin: 0;
  padding-left: 16px;
  border-left: 3px solid var(--amber-500);
  font-size: 15px;
  line-height: 1.88;
  color: var(--mist-500);
}

.page-about .about-reach .about-media {
  margin: 0;
}

/* ---------- 资质 ---------- */
.page-about .about-badges {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
}

.page-about .about-badge {
  display: grid;
  gap: 8px;
  background: var(--mist-050);
  border: 1px solid var(--mist-200);
  padding: clamp(18px, 2.4vw, 24px);
}

.page-about .about-badge__mark {
  display: inline-block;
  justify-self: start;
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--ink-900);
  background: var(--amber-200);
  padding: 4px 10px;
  clip-path: polygon(6px 0, 100% 0, 100% 100%, 0 100%, 0 6px);
}

.page-about .about-badge h3 {
  margin: 0;
  font-size: 16.5px;
  font-weight: 700;
  line-height: 1.5;
  color: var(--ink-900);
}

.page-about .about-badge p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.82;
  color: var(--ink-700);
}

/* ---------- 对接引导 ---------- */
.page-about .about-start {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: rgba(252, 251, 248, .18);
  border: 1px solid rgba(252, 251, 248, .18);
}

.page-about .about-start__item {
  display: block;
  padding: clamp(22px, 3vw, 32px);
  background: var(--ink-900);
  text-decoration: none;
  color: inherit;
  transition: background-color .22s ease;
}

.page-about .about-start__item:hover {
  background: var(--ink-700);
}

.page-about .about-start__no {
  display: block;
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--amber-500);
  margin-bottom: 12px;
}

.page-about .about-start__item h3 {
  margin: 0 0 10px;
  font-size: 18px;
  font-weight: 700;
  line-height: 1.5;
  color: var(--paper);
}

.page-about .about-start__item p {
  margin: 0 0 18px;
  font-size: 15px;
  line-height: 1.85;
  color: var(--mist-200);
}

.page-about .about-start__go {
  font-size: 14px;
  font-weight: 700;
  color: var(--amber-500);
}

.page-about .about-signoff {
  margin-top: clamp(28px, 4vw, 44px);
  padding-top: 22px;
  border-top: 1px solid rgba(252, 251, 248, .18);
}

.page-about .about-signoff p {
  margin: 0;
  max-width: 60ch;
  font-size: 15.5px;
  line-height: 1.9;
  color: var(--mist-200);
}

/* ---------- 平板及以上 ---------- */
@media (min-width: 720px) {
  .page-about .about-values {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-sources {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 24px;
  }

  .page-about .about-crew {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 18px;
  }

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

  .page-about .about-bridge {
    grid-template-columns: 1fr auto;
    align-items: center;
  }

  .page-about .about-bridge__tag {
    grid-column: 1 / -1;
  }

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

/* ---------- 桌面端 ---------- */
@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.5fr) minmax(250px, .85fr);
    align-items: end;
  }

  .page-about .about-timeline {
    position: relative;
    gap: 20px;
  }

  .page-about .about-timeline::before {
    content: "";
    position: absolute;
    left: calc(var(--about-rail) - 1px);
    top: 8px;
    bottom: 8px;
    width: 1px;
    background: var(--mist-200);
  }

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

  .page-about .about-timeline__marker {
    text-align: right;
    padding-right: 26px;
    padding-top: 18px;
  }

  .page-about .about-timeline__marker::after {
    content: "";
    position: absolute;
    right: -5px;
    top: 25px;
    width: 9px;
    height: 9px;
    border-radius: 50%;
    background: var(--amber-500);
  }

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

  .page-about .about-reach {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, .85fr);
    align-items: start;
  }

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

/* ---------- 大屏微调 ---------- */
@media (min-width: 1180px) {
  .page-about .about-hero__facts {
    padding: 34px 32px;
  }

  .page-about .about-value {
    padding: 30px 28px;
  }
}

/* ---------- 动效降级 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .about-crew__item,
  .page-about .about-start__item,
  .page-about .about-bridge__link,
  .page-about .crumbs a {
    transition: none;
  }

  .page-about .about-crew__item:hover {
    transform: none;
  }
}
</main>