.page-about {
  --about-bg: var(--c-space-900);
  --about-dark: var(--c-space-950);
  --about-line: var(--c-line);
  --about-orange: var(--c-orange);
  --about-yellow: var(--c-yellow);
  --about-field: var(--c-field);
  --about-night: var(--c-night);
  --about-ease: var(--ease-out);
  background:
    linear-gradient(180deg, var(--about-bg) 0%, var(--c-space-950) 100%);
  color: var(--about-field);
  overflow: hidden;
}

.page-about .container {
  padding-inline: clamp(16px, 4vw, 40px);
}

.page-about .breadcrumb {
  margin: 24px 0 8px;
}

.page-about .section-kicker {
  margin-bottom: 12px;
}

/* ===== Hero ===== */
.page-about .about-hero {
  position: relative;
  display: grid;
  gap: 24px;
  padding: 32px 0 56px;
}

.page-about .about-hero-watermark {
  position: absolute;
  top: 36px;
  right: -20px;
  z-index: 0;
  pointer-events: none;
  font-family: var(--font-head);
  font-size: clamp(72px, 18vw, 220px);
  line-height: 1;
  letter-spacing: -0.04em;
  text-transform: uppercase;
  color: transparent;
  -webkit-text-stroke: 1px rgba(245, 247, 250, 0.08);
  white-space: nowrap;
  user-select: none;
}

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

.page-about .about-hero-copy h1 {
  font-family: var(--font-head);
  font-size: clamp(34px, 6vw, 72px);
  line-height: 1.04;
  letter-spacing: -0.02em;
  text-transform: uppercase;
  margin: 0 0 16px;
  max-width: 12ch;
}

.page-about .about-hero-lead {
  font-size: clamp(17px, 2.2vw, 22px);
  font-weight: 600;
  color: var(--about-yellow);
  line-height: 1.5;
  margin: 0 0 16px;
  max-width: 46ch;
}

.page-about .about-hero-note {
  font-size: 16px;
  line-height: 1.8;
  color: var(--about-night);
  margin: 0;
  max-width: 56ch;
}

.page-about .about-hero-facts {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1px;
  background: var(--about-line);
  border: 1px solid var(--about-line);
  margin-top: 28px;
  max-width: 680px;
}

.page-about .about-fact {
  background: var(--about-dark);
  padding: 16px;
}

.page-about .about-fact-num {
  display: block;
  font-family: var(--font-num);
  font-size: 26px;
  line-height: 1.1;
  color: var(--about-orange);
}

.page-about .about-fact-label {
  display: block;
  margin-top: 6px;
  font-size: 12px;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--about-night);
}

.page-about .about-hero-media {
  position: relative;
  z-index: 1;
  margin: 0;
}

/* ===== 品牌定位 ===== */
.page-about .about-positioning {
  padding: 48px 0 64px;
}

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

.page-about .about-positioning-head {
  position: relative;
  padding-left: 16px;
  border-left: 4px solid var(--about-orange);
}

.page-about .about-positioning-head h2,
.page-about .about-timeline-head h2,
.page-about .about-team-head h2,
.page-about .about-accreditation-head h2,
.page-about .about-partners-copy h2,
.page-about .about-cta-card h2 {
  font-family: var(--font-head);
  font-size: clamp(28px, 4vw, 44px);
  line-height: 1.1;
  letter-spacing: -0.01em;
  margin: 0;
  text-transform: uppercase;
}

.page-about .about-positioning-body p {
  font-size: 16px;
  line-height: 1.85;
  color: var(--about-field);
  margin: 0 0 16px;
  max-width: 72ch;
}

.page-about .about-positioning-body p:last-child {
  margin-bottom: 0;
}

/* ===== 时间轴 ===== */
.page-about .about-timeline {
  padding: 56px 0 64px;
}

.page-about .about-timeline-head {
  margin-bottom: 40px;
  max-width: 56ch;
}

.page-about .about-timeline-head p:not(.section-kicker) {
  font-size: 16px;
  line-height: 1.8;
  color: var(--about-night);
  margin: 16px 0 0;
}

.page-about .about-timeline-track {
  position: relative;
  padding: 8px 0 8px;
}

.page-about .about-milestone {
  position: relative;
  display: grid;
  grid-template-columns: 30px 1fr;
  column-gap: 16px;
  padding-bottom: 32px;
}

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

.page-about .about-milestone::before {
  content: "";
  position: absolute;
  left: 13px;
  top: 10px;
  bottom: -2px;
  width: 2px;
  background: linear-gradient(180deg, var(--about-orange), var(--about-line));
}

.page-about .about-milestone:last-child::before {
  display: none;
}

.page-about .about-milestone-dot {
  grid-column: 1;
  grid-row: 1;
  justify-self: center;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  margin-top: 12px;
  background: var(--about-orange);
  box-shadow: 0 0 0 4px rgba(255, 108, 0, 0.18);
}

.page-about .about-milestone-year {
  grid-column: 2;
  grid-row: 1;
  font-family: var(--font-num);
  font-size: 32px;
  line-height: 1.2;
  font-weight: 700;
  color: var(--about-orange);
  letter-spacing: -0.02em;
}

.page-about .about-milestone-card {
  grid-column: 2;
  grid-row: 2;
  margin-top: 10px;
  padding: 20px;
  border-top: 2px solid var(--about-orange);
}

.page-about .about-milestone-card h3 {
  font-family: var(--font-head);
  font-size: 18px;
  line-height: 1.3;
  margin: 0 0 10px;
  color: var(--about-field);
  text-transform: uppercase;
  letter-spacing: -0.01em;
}

.page-about .about-milestone-card p {
  font-size: 15px;
  line-height: 1.75;
  color: var(--about-night);
  margin: 0;
  max-width: 58ch;
}

.page-about .about-timeline-more {
  margin-top: 32px;
  text-align: right;
}

.page-about .about-timeline-more a {
  color: var(--about-orange);
}

/* ===== 团队 ===== */
.page-about .about-team {
  padding: 56px 0 64px;
}

.page-about .about-team-head {
  margin-bottom: 32px;
}

.page-about .about-team-layout {
  display: grid;
  gap: 24px;
  align-items: stretch;
}

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

.page-about .about-team-summary {
  padding: 28px 24px;
  border-top: 4px solid var(--about-yellow);
}

.page-about .about-team-num {
  display: block;
  font-family: var(--font-num);
  font-size: 68px;
  line-height: 1;
  color: var(--about-orange);
  font-weight: 700;
}

.page-about .about-team-summary-title {
  font-size: 18px;
  font-weight: 700;
  color: var(--about-field);
  margin: 8px 0 16px;
}

.page-about .about-team-summary > p:last-child {
  font-size: 15px;
  line-height: 1.8;
  color: var(--about-night);
  margin: 0;
}

.page-about .about-team-grid {
  display: grid;
  gap: 16px;
  margin-top: 24px;
}

.page-about .about-team-card {
  padding: 22px 20px;
  border-left: 3px solid var(--about-line);
}

.page-about .about-team-card h3 {
  font-family: var(--font-head);
  font-size: 16px;
  line-height: 1.3;
  margin: 0 0 10px;
  color: var(--about-orange);
  text-transform: uppercase;
}

.page-about .about-team-card p {
  font-size: 15px;
  line-height: 1.75;
  color: var(--about-night);
  margin: 0;
}

/* ===== 资质 ===== */
.page-about .about-accreditation {
  padding: 24px 0 64px;
}

.page-about .about-accreditation-wrap {
  background: var(--about-dark);
  padding: 32px 20px;
  border-top: 3px solid var(--about-orange);
}

.page-about .about-accreditation-head {
  margin-bottom: 28px;
}

.page-about .about-accreditation-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
}

.page-about .about-credential {
  position: relative;
  background: var(--about-bg);
  border: 1px solid var(--about-line);
  padding: 20px 16px;
  min-height: 150px;
  transition:
    transform 0.4s var(--about-ease),
    border-color 0.4s var(--about-ease),
    background-color 0.4s var(--about-ease);
  transform-style: preserve-3d;
  will-change: transform;
}

.page-about .about-credential:hover,
.page-about .about-credential:focus-within {
  transform: perspective(700px) rotateX(5deg) translateY(-5px);
  border-color: var(--about-orange);
  background: linear-gradient(145deg, var(--c-space-900), var(--c-space-950));
}

.page-about .about-credential-icon {
  display: block;
  width: 38px;
  height: 38px;
  margin-bottom: 14px;
  background: var(--about-orange);
  clip-path: polygon(0 0, 100% 0, 100% 68%, 68% 100%, 0 100%);
}

.page-about .about-credential-icon::after {
  content: "";
  position: absolute;
  top: 6px;
  left: 6px;
  width: 26px;
  height: 26px;
  background: var(--about-yellow);
  clip-path: polygon(0 0, 100% 0, 100% 68%, 68% 100%, 0 100%);
}

.page-about .about-credential h3 {
  font-family: var(--font-head);
  font-size: 15px;
  line-height: 1.4;
  margin: 0 0 8px;
  color: var(--about-field);
  text-transform: uppercase;
}

.page-about .about-credential p {
  font-size: 13px;
  line-height: 1.6;
  color: var(--about-night);
  margin: 0;
}

/* ===== 合作生态 ===== */
.page-about .about-partners {
  padding: 48px 0 64px;
}

.page-about .about-partners-layout {
  display: grid;
  gap: 28px;
  align-items: center;
}

.page-about .about-partners-copy p:not(.section-kicker) {
  font-size: 16px;
  line-height: 1.85;
  color: var(--about-night);
  margin: 0 0 16px;
  max-width: 56ch;
}

.page-about .about-partners-copy .btn {
  margin-top: 8px;
}

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

/* ===== CTA ===== */
.page-about .about-cta {
  padding: 24px 0 72px;
}

.page-about .about-cta-card {
  background: linear-gradient(135deg, var(--about-dark), var(--c-space-900));
  border-top: 4px solid var(--about-orange);
  padding: 32px 20px;
  clip-path: polygon(0 0, calc(100% - 22px) 0, 100% 22px, 100% 100%, 0 100%);
}

.page-about .about-cta-card h2 {
  margin-top: 12px;
}

.page-about .about-cta-card p:not(.section-kicker) {
  font-size: 16px;
  line-height: 1.8;
  color: var(--about-night);
  margin: 16px 0 24px;
  max-width: 62ch;
}

.page-about .about-cta-links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.page-about .about-cta-links .btn {
  margin: 0;
}

/* ===== Reveal 动画与动效 === */
.page-about [data-reveal] {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.5s var(--about-ease), transform 0.5s var(--about-ease);
}

.page-about [data-reveal].is-in {
  opacity: 1;
  transform: none;
}

@media (prefers-reduced-motion: reduce) {
  .page-about [data-reveal] {
    opacity: 1;
    transform: none;
    transition: none;
  }

  .page-about .about-credential {
    transform: none;
    transition: border-color 0.2s linear;
  }

  .page-about .about-credential:hover,
  .page-about .about-credential:focus-within {
    transform: none;
  }
}

/* ===== 桌面布局 ===== */
@media (min-width: 700px) {
  .page-about .about-hero-facts {
    grid-template-columns: repeat(4, 1fr);
  }

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

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

@media (min-width: 900px) {
  .page-about .about-hero {
    grid-template-columns: minmax(0, 5fr) minmax(0, 4fr);
    gap: 40px;
    align-items: start;
    padding-top: 56px;
  }

  .page-about .about-hero-copy h1 {
    max-width: 10ch;
  }

  .page-about .about-hero-media {
    margin-top: 40px;
  }

  .page-about .about-positioning-grid {
    grid-template-columns: 0.8fr 1.4fr;
    gap: 60px;
  }

  .page-about .about-timeline-head {
    max-width: 60ch;
  }

  .page-about .about-timeline-track::before {
    content: "";
    position: absolute;
    left: 50%;
    top: 0;
    bottom: 0;
    width: 2px;
    transform: translateX(-1px);
    background: linear-gradient(180deg, var(--about-orange), var(--about-line));
    z-index: 0;
  }

  .page-about .about-milestone {
    grid-template-columns: 1fr 1fr;
    column-gap: 72px;
    padding-bottom: 48px;
  }

  .page-about .about-milestone::before {
    display: none;
  }

  .page-about .about-milestone-dot {
    position: absolute;
    left: 50%;
    top: 18px;
    transform: translateX(-50%);
    width: 16px;
    height: 16px;
    margin-top: 0;
    z-index: 1;
  }

  .page-about .about-milestone-year {
    grid-row: 1;
    align-self: start;
    font-size: clamp(40px, 5vw, 72px);
    line-height: 1.1;
  }

  .page-about .about-milestone-card {
    grid-row: 2;
    margin-top: 6px;
  }

  .page-about .about-milestone:nth-child(odd) .about-milestone-year,
  .page-about .about-milestone:nth-child(odd) .about-milestone-card {
    grid-column: 1;
  }

  .page-about .about-milestone:nth-child(even) .about-milestone-year,
  .page-about .about-milestone:nth-child(even) .about-milestone-card {
    grid-column: 2;
  }

  .page-about .about-milestone:nth-child(odd) .about-milestone-year {
    text-align: right;
  }

  .page-about .about-team-layout {
    grid-template-columns: 1.2fr 0.8fr;
    gap: 28px;
    align-items: center;
  }

  .page-about .about-team-summary {
    padding: 36px 28px;
  }

  .page-about .about-partners-layout {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.1fr);
    gap: 56px;
  }

  .page-about .about-cta-card {
    padding: 48px 40px;
  }
}