.page-about {
  --about-line: rgba(255, 255, 255, 0.09);
  --about-line-strong: rgba(255, 255, 255, 0.16);
  background-color: var(--color-bg);
  background-image:
    linear-gradient(var(--about-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--about-line) 1px, transparent 1px);
  background-size: 44px 44px;
  color: var(--color-white);
}

.page-about .about-hero {
  padding: 20px 0 48px;
  position: relative;
}

.page-about .about-hero__grid {
  display: grid;
  gap: 36px;
  align-items: center;
  margin-top: 28px;
}

.page-about .about-hero__title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(38px, 6vw, 72px);
  line-height: 0.98;
  letter-spacing: 0.01em;
  margin: 16px 0 18px;
  transform: skewX(-4deg);
  color: var(--color-white);
}

.page-about .lede {
  font-size: clamp(17px, 2vw, 22px);
  color: var(--color-gray);
  line-height: 1.6;
  max-width: 56ch;
}

.page-about .about-hero__text {
  color: var(--color-gray);
  line-height: 1.75;
  margin-top: 16px;
  max-width: 58ch;
  font-size: 15px;
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

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

.page-about .about-hero__frame {
  position: relative;
  border: 1px solid var(--color-line);
  background: var(--color-glass);
  border-radius: var(--radius);
  padding: 12px;
  margin: 12px 6px 6px 12px;
}

.page-about .about-hero__img {
  display: block;
  width: 100%;
  height: auto;
  border-radius: calc(var(--radius) - 4px);
  object-fit: cover;
  aspect-ratio: 3 / 2;
}

.page-about .about-hero__frame::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, transparent 70%, rgba(255, 106, 0, 0.14) 100%);
  border-radius: calc(var(--radius) - 4px);
  pointer-events: none;
}

.page-about .about-hero__lines {
  position: absolute;
  top: -22px;
  right: -6px;
  width: 120px;
  height: 120px;
  opacity: 0.65;
  pointer-events: none;
}

.page-about .about-hero__visual::before {
  content: "";
  position: absolute;
  top: 2px;
  right: 30px;
  width: 120px;
  height: 6px;
  background: var(--color-primary);
  transform: rotate(-28deg);
  border-radius: 4px;
  z-index: 1;
}

.page-about .about-hero__visual::after {
  content: "";
  position: absolute;
  bottom: 18px;
  left: -20px;
  width: 88px;
  height: 4px;
  background: var(--color-yellow);
  transform: rotate(32deg);
  border-radius: 4px;
  opacity: 0.85;
}

/* 使命 */
.page-about .about-mission {
  padding: 64px 0;
  background: rgba(255, 255, 255, 0.03);
  border-top: 1px solid var(--color-line);
  border-bottom: 1px solid var(--color-line);
}

.page-about .about-mission__grid {
  display: grid;
  gap: 28px;
}

.page-about .about-mission__copy p {
  color: var(--color-gray);
  line-height: 1.8;
  font-size: 16px;
  margin: 0 0 16px;
}

.page-about .about-mission__principles {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 14px;
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
}

.page-about .about-mission__principles li {
  background: var(--color-glass);
  border: 1px solid var(--color-line);
  border-radius: 999px;
  padding: 8px 16px;
  font-size: 13px;
  color: var(--color-white);
  letter-spacing: 0.02em;
}

/* 时间轴 */
.page-about .about-timeline {
  padding: 72px 0;
  overflow: hidden;
}

.page-about .about-timeline__list {
  list-style: none;
  margin: 44px 0 0;
  padding: 0;
  position: relative;
  display: grid;
  gap: 28px;
}

.page-about .about-timeline__list::before {
  content: "";
  position: absolute;
  top: 8px;
  bottom: 8px;
  left: 16px;
  width: 2px;
  transform: translateX(-1px);
  background: linear-gradient(
    to bottom,
    var(--color-primary) 0%,
    var(--color-line-strong) 26%,
    var(--color-line) 72%,
    var(--color-primary) 100%
  );
}

.page-about .about-timeline__item {
  position: relative;
  padding-left: 52px;
}

.page-about .about-timeline__node {
  position: absolute;
  left: 0;
  top: 2px;
  display: flex;
  flex-direction: column;
  align-items: center;
  width: 32px;
  text-align: center;
}

.page-about .about-timeline__dot {
  display: block;
  margin: 0 auto;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--color-primary);
  box-shadow:
    0 0 0 4px rgba(255, 106, 0, 0.22),
    0 0 24px rgba(255, 106, 0, 0.55);
}

.page-about .about-timeline__num {
  margin-top: 8px;
  font-family: var(--font-data);
  font-size: 11px;
  color: var(--color-gray);
  letter-spacing: 0.06em;
}

.page-about .about-timeline__card {
  background: var(--color-glass);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  padding: 20px;
  transition: border-color var(--ease), background var(--ease);
}

.page-about .about-timeline__card:hover,
.page-about .about-timeline__card:focus-within {
  border-color: rgba(255, 106, 0, 0.45);
  background: var(--color-glass-strong);
}

.page-about .about-timeline__card h3 {
  font-size: 20px;
  line-height: 1.25;
  margin: 12px 0 8px;
  color: var(--color-white);
}

.page-about .about-timeline__card p {
  color: var(--color-gray);
  font-size: 14px;
  line-height: 1.7;
  margin: 0;
}

.page-about .about-timeline__details {
  border-top: 1px dashed var(--color-line);
  margin-top: 14px;
  padding-top: 12px;
}

.page-about .about-timeline__details summary {
  cursor: pointer;
  list-style: none;
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  color: var(--color-yellow);
  font-weight: 600;
}

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

.page-about .about-timeline__details summary::before {
  content: "+";
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 20px;
  height: 20px;
  border: 1px solid var(--color-primary);
  border-radius: 50%;
  color: var(--color-primary);
  font-family: var(--font-data);
  font-size: 14px;
  line-height: 1;
}

.page-about .about-timeline__details[open] summary::before {
  content: "\2013";
}

.page-about .about-timeline__details p {
  padding-top: 14px;
  border: 0;
  margin: 0;
}

/* 数据能力 */
.page-about .about-data {
  padding: 72px 0;
  background: rgba(255, 255, 255, 0.02);
  border-top: 1px solid var(--color-line);
}

.page-about .about-data__grid {
  display: grid;
  gap: 36px;
  align-items: center;
}

.page-about .about-data__stats {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  margin-top: 28px;
}

.page-about .about-data__stat {
  background: var(--color-glass);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  padding: 18px;
  display: flex;
  flex-direction: column;
  gap: 6px;
  transition: border-color var(--ease), transform var(--ease);
}

.page-about .about-data__stat:hover {
  border-color: rgba(255, 215, 0, 0.4);
  transform: translateY(-2px);
}

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

.page-about .about-data__number {
  font-family: var(--font-data);
  font-size: clamp(26px, 4vw, 40px);
  font-weight: 700;
  line-height: 1.1;
  color: var(--color-primary);
}

.page-about .about-data__stat:nth-child(2) .about-data__number {
  color: var(--color-yellow);
}

.page-about .about-data__stat:nth-child(3) .about-data__number {
  color: var(--color-green);
}

.page-about .about-data__suffix {
  font-size: 13px;
  color: var(--color-gray);
}

.page-about .about-data__note {
  margin-top: 22px;
  color: var(--color-gray);
  font-size: 14px;
  line-height: 1.75;
  border-left: 3px solid var(--color-primary);
  padding-left: 14px;
}

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

.page-about .about-data__img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  background: var(--color-glass);
  object-fit: cover;
}

.page-about .about-data__visual::before {
  content: "";
  position: absolute;
  top: -14px;
  right: -14px;
  width: 62px;
  height: 62px;
  border-top: 3px solid var(--color-primary);
  border-right: 3px solid var(--color-primary);
  border-radius: 0 var(--radius) 0 0;
  opacity: 0.8;
}

/* 专家团队 */
.page-about .about-experts {
  padding: 72px 0;
  background: linear-gradient(180deg, rgba(10, 26, 48, 0.4), rgba(14, 34, 64, 0.72));
  border-top: 1px solid var(--color-line);
}

.page-about .about-experts__cards {
  display: grid;
  gap: 18px;
  margin-top: 32px;
}

.page-about .about-expert__card {
  background: var(--color-glass);
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  padding: 22px;
  position: relative;
  overflow: hidden;
  transition: border-color var(--ease), background var(--ease), transform var(--ease);
}

.page-about .about-expert__card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 4px;
  height: 100%;
  background: var(--color-primary);
}

.page-about .about-expert__card:nth-child(2)::before {
  background: var(--color-yellow);
}

.page-about .about-expert__card:nth-child(3)::before {
  background: var(--color-green);
}

.page-about .about-expert__card:nth-child(4)::before {
  background: var(--color-gray);
}

.page-about .about-expert__card:hover {
  border-color: rgba(255, 106, 0, 0.4);
  background: var(--color-glass-strong);
  transform: translateY(-2px);
}

.page-about .about-expert__code {
  font-family: var(--font-data);
  font-size: 24px;
  font-weight: 700;
  color: var(--color-primary);
  letter-spacing: 0.02em;
}

.page-about .about-expert__card:nth-child(2) .about-expert__code {
  color: var(--color-yellow);
}

.page-about .about-expert__card:nth-child(3) .about-expert__code {
  color: var(--color-green);
}

.page-about .about-expert__card h3 {
  font-size: 18px;
  margin: 12px 0 8px;
  color: var(--color-white);
}

.page-about .about-expert__card p {
  color: var(--color-gray);
  font-size: 14px;
  line-height: 1.65;
  margin: 0 0 16px;
}

.page-about .about-experts__bottom {
  display: grid;
  gap: 28px;
  margin-top: 40px;
  align-items: center;
}

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

.page-about .about-experts__img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--color-line);
  border-radius: var(--radius);
  background: var(--color-glass);
  object-fit: cover;
}

.page-about .about-experts__media::after {
  content: "";
  position: absolute;
  bottom: -14px;
  left: -14px;
  width: 60px;
  height: 60px;
  border-bottom: 3px solid var(--color-green);
  border-left: 3px solid var(--color-green);
  border-radius: 0 0 0 var(--radius);
  opacity: 0.7;
}

.page-about .about-experts__text h3 {
  font-size: 22px;
  color: var(--color-white);
  margin: 0 0 12px;
}

.page-about .about-experts__text p {
  color: var(--color-gray);
  line-height: 1.75;
  font-size: 15px;
  margin: 0 0 14px;
}

.page-about .about-experts__text .btn {
  margin-top: 6px;
}

/* 结尾 CTA */
.page-about .about-cta {
  padding: 72px 0;
  text-align: center;
  position: relative;
  border-top: 1px solid var(--color-line);
  background:
    radial-gradient(circle at center, rgba(255, 106, 0, 0.16) 0%, transparent 70%),
    rgba(255, 255, 255, 0.02);
}

.page-about .about-cta h2 {
  font-size: clamp(24px, 4vw, 40px);
  color: var(--color-white);
  margin: 0 0 16px;
  transform: skewX(-3deg);
  font-family: var(--font-display);
  font-weight: 800;
  line-height: 1.1;
}

.page-about .about-cta p {
  color: var(--color-gray);
  max-width: 60ch;
  margin: 0 auto 28px;
  line-height: 1.8;
  font-size: 15px;
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
}

/* 桌面端增强 */
@media (min-width: 900px) {
  .page-about .about-hero {
    padding: 32px 0 72px;
  }

  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    gap: 60px;
    margin-top: 40px;
  }

  .page-about .about-hero__title {
    font-size: clamp(52px, 6vw, 78px);
  }

  .page-about .about-hero__actions {
    margin-top: 32px;
  }

  .page-about .about-mission {
    padding: 88px 0;
  }

  .page-about .about-mission__grid {
    grid-template-columns: minmax(280px, 0.85fr) 1.2fr;
    gap: 72px;
    align-items: start;
  }

  .page-about .about-timeline {
    padding: 96px 0;
  }

  .page-about .about-timeline__list {
    gap: 44px;
    margin-top: 56px;
  }

  .page-about .about-timeline__item {
    padding-left: 84px;
  }

  .page-about .about-timeline__list::before {
    left: 24px;
  }

  .page-about .about-timeline__node {
    width: 48px;
  }

  .page-about .about-timeline__dot {
    width: 18px;
    height: 18px;
  }

  .page-about .about-timeline__card {
    padding: 28px 32px;
  }

  .page-about .about-data {
    padding: 96px 0;
  }

  .page-about .about-data__grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.9fr);
    gap: 64px;
  }

  .page-about .about-data__stats {
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
  }

  .page-about .about-experts {
    padding: 96px 0;
  }

  .page-about .about-experts__cards {
    grid-template-columns: repeat(4, 1fr);
    gap: 22px;
  }

  .page-about .about-experts__bottom {
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.85fr);
    gap: 56px;
    margin-top: 56px;
  }

  .page-about .about-cta {
    padding: 96px 0;
  }
}

.page-about {
  --color-line-strong: transparent;
}