.page-about {
  --about-navy: #0A1E3F;
  --about-navy-deep: #071429;
  --about-orange: #FF6B35;
  --about-light: #F5F7FA;
  --about-white: #FFFFFF;
  --about-border: #D0D7DE;
  --about-text-secondary: #5A6B7A;
  --about-shadow: 10px 10px 0 rgba(10, 30, 63, 0.12);
  --about-shadow-lg: 16px 16px 0 rgba(10, 30, 63, 0.16);
  --about-radius: 2px;
  background: var(--about-light);
  color: var(--about-navy);
  font-family: var(--font-body);
  overflow-x: hidden;
}

.page-about__container {
  width: min(1280px, 100% - 2rem * 2);
  margin-inline: auto;
}

@media (max-width: 767px) {
  .page-about__container {
    width: min(1280px, 100vw - 3rem);
    padding-inline: 0;
  }
}

@media (max-width: 479px) {
  .page-about__container {
    width: min(1280px, 100vw - 2.5rem);
  }
}

/* ============ 首屏 intro ============ */
.page-about__intro {
  background: var(--about-navy);
  color: var(--about-white);
  padding: 3rem 0 4rem;
  position: relative;
  overflow: hidden;
}

.page-about__intro::before {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 55%;
  height: 100%;
  background: linear-gradient(135deg, transparent 0 55%, rgba(255, 107, 53, 0.22) 55% 100%);
  clip-path: polygon(100% 0, 100% 100%, 30% 100%, 60% 0);
  pointer-events: none;
}

.page-about__intro::after {
  content: "2018";
  position: absolute;
  right: 1rem;
  bottom: 1rem;
  font-family: var(--font-display);
  font-size: clamp(4rem, 14vw, 12rem);
  line-height: 0.8;
  color: rgba(255, 107, 53, 0.18);
  font-weight: 900;
  pointer-events: none;
  letter-spacing: -0.04em;
}

.page-about__intro-inner {
  width: min(1280px, 100% - 2rem * 2);
  margin-inline: auto;
  position: relative;
  z-index: 2;
}

@media (max-width: 767px) {
  .page-about__intro-inner {
    width: min(1280px, 100vw - 3rem);
  }
}

@media (max-width: 479px) {
  .page-about__intro-inner {
    width: min(1280px, 100vw - 2.5rem);
  }
}

.page-about__intro .breadcrumb {
  margin-bottom: 2.5rem;
}

.page-about__intro .breadcrumb-list {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about__intro .breadcrumb-item {
  font-size: 0.875rem;
  color: rgba(245, 247, 250, 0.7);
}

.page-about__intro .breadcrumb-item a {
  color: rgba(245, 247, 250, 0.7);
  text-decoration: none;
  transition: color 0.2s ease;
}

.page-about__intro .breadcrumb-item a:hover {
  color: var(--about-orange);
}

.page-about__intro .breadcrumb-item[aria-current="page"] {
  color: var(--about-white);
  font-weight: 600;
}

.page-about__intro .breadcrumb-sep {
  color: rgba(245, 247, 250, 0.4);
  font-family: var(--font-mono);
}

.page-about__intro-grid {
  display: grid;
  grid-template-columns: 1fr minmax(320px, 400px);
  gap: 3rem;
  align-items: start;
}

@media (max-width: 980px) {
  .page-about__intro-grid {
    grid-template-columns: 1fr;
  }
}

.page-about__intro-copy {
  max-width: 840px;
}

.page-about__eyebrow {
  display: inline-flex;
  align-items: center;
  gap: 0.625rem;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: rgba(245, 247, 250, 0.75);
  margin-bottom: 1.25rem;
  border: 1px solid rgba(255, 255, 255, 0.25);
  padding: 0.35rem 0.75rem;
  background: rgba(255, 255, 255, 0.04);
}

.page-about__title {
  font-family: var(--font-display);
  font-size: clamp(2rem, 5vw, 3.25rem);
  font-weight: 900;
  line-height: 1.1;
  margin: 0 0 1.5rem;
  color: var(--about-white);
  letter-spacing: -0.01em;
}

.page-about__lead {
  font-size: 1.125rem;
  line-height: 1.7;
  color: rgba(245, 247, 250, 0.85);
  margin-bottom: 2rem;
  max-width: 58ch;
}

.page-about__intro-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
}

.page-about__intro-actions .btn-primary {
  background: var(--about-orange);
  border: 2px solid var(--about-orange);
  color: var(--about-navy);
  font-weight: 700;
  padding: 0.75rem 1.75rem;
  text-decoration: none;
  display: inline-block;
  box-shadow: 4px 4px 0 rgba(255, 107, 53, 0.35);
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.page-about__intro-actions .btn-primary:hover {
  transform: translate(-2px, -2px);
  box-shadow: 6px 6px 0 rgba(255, 107, 53, 0.45);
}

.page-about__intro-actions .btn-outline {
  background: transparent;
  border: 2px solid rgba(255, 255, 255, 0.7);
  color: var(--about-white);
  font-weight: 600;
  padding: 0.75rem 1.75rem;
  text-decoration: none;
  display: inline-block;
  transition: border-color 0.2s ease, background 0.2s ease;
}

.page-about__intro-actions .btn-outline:hover {
  border-color: var(--about-orange);
  color: var(--about-orange);
}

.page-about__quick-nav {
  background: rgba(255, 255, 255, 0.06);
  border: 2px solid rgba(255, 255, 255, 0.2);
  padding: 1.75rem 1.5rem;
  backdrop-filter: blur(4px);
  box-shadow: 10px 10px 0 rgba(0, 0, 0, 0.25);
}

.page-about__quick-nav-title {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.15em;
  color: var(--about-orange);
  margin-bottom: 1.25rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.15);
}

.page-about__quick-nav-list {
  list-style: none;
  margin: 0 0 1.5rem;
  padding: 0;
  counter-reset: quicknav;
}

.page-about__quick-nav-list li {
  margin-bottom: 0.4rem;
}

.page-about__quick-nav-list a {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.65rem 0.5rem;
  color: rgba(245, 247, 250, 0.85);
  text-decoration: none;
  font-weight: 500;
  border-left: 3px solid transparent;
  transition: border-color 0.2s ease, color 0.2s ease, background 0.2s ease;
}

.page-about__quick-nav-list a:hover {
  border-left-color: var(--about-orange);
  color: var(--about-white);
  background: rgba(255, 107, 53, 0.08);
}

.page-about__quick-nav-num {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--about-orange);
  min-width: 2ch;
}

.page-about__quick-nav-foot {
  margin-top: 1rem;
  padding-top: 1rem;
  border-top: 1px dashed rgba(255, 255, 255, 0.2);
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.page-about__quick-nav-label {
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  color: rgba(245, 247, 250, 0.5);
}

.page-about__quick-nav-value {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  color: var(--about-orange);
  font-weight: 600;
}

/* ============ 通用 section 与 sec-head ============ */
.page-about__section {
  padding: 4.5rem 0;
}

@media (max-width: 767px) {
  .page-about__section {
    padding: 3rem 0;
  }
}

.page-about__section .sec-head {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 2.5rem;
  gap: 2rem;
}

@media (max-width: 767px) {
  .page-about__section .sec-head {
    flex-direction: column;
    align-items: flex-start;
    gap: 0.75rem;
  }
}

.page-about__section .sec-head-left {
  display: flex;
  align-items: baseline;
  gap: 1.25rem;
}

.page-about__section .sec-index {
  font-family: var(--font-mono);
  font-size: 0.875rem;
  color: var(--about-orange);
  font-weight: 600;
}

.page-about__section .sec-title {
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 3vw, 2rem);
  font-weight: 700;
  margin: 0;
  line-height: 1.3;
}

.page-about__section .sec-link {
  color: var(--about-orange);
  text-decoration: none;
  font-weight: 500;
  font-size: 0.875rem;
  border-bottom: 2px solid transparent;
  transition: border-color 0.2s ease;
}

.page-about__section .sec-link:hover {
  border-bottom-color: var(--about-orange);
}

/* ============ who we are ============ */
.page-about__who {
  background: var(--about-light);
}

.page-about__who-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 3rem;
  align-items: center;
}

@media (max-width: 900px) {
  .page-about__who-grid {
    grid-template-columns: 1fr;
  }
}

.page-about__who-copy p {
  font-size: 1rem;
  line-height: 1.7;
  margin-bottom: 1.25rem;
}

.page-about__value-list {
  list-style: none;
  margin: 1.5rem 0 0;
  padding: 0;
  border-top: 2px solid var(--about-navy);
}

.page-about__value-list li {
  padding: 0.85rem 0 0.85rem 1.25rem;
  border-bottom: 1px solid var(--about-border);
  position: relative;
  font-size: 0.9375rem;
  line-height: 1.6;
}

.page-about__value-list li::before {
  content: "▸";
  position: absolute;
  left: 0;
  color: var(--about-orange);
  font-family: var(--font-mono);
}

.page-about__value-list strong {
  font-weight: 700;
  color: var(--about-navy);
  margin-right: 0.5rem;
}

.page-about__who-figure {
  margin: 0;
  border: 2px solid var(--about-navy);
  box-shadow: var(--about-shadow-lg);
}

.page-about__who-img {
  width: 100%;
  height: auto;
  display: block;
  object-fit: cover;
  aspect-ratio: 16 / 9;
}

/* ============ milestones timeline ============ */
.page-about__milestones {
  background: var(--about-white);
  border-block: 2px solid var(--about-border);
}

.page-about__timeline {
  position: relative;
  padding-left: 2.5rem;
}

@media (max-width: 767px) {
  .page-about__timeline {
    padding-left: 1.25rem;
  }
}

.page-about__timeline::before {
  content: "";
  position: absolute;
  left: 9px;
  top: 0.5rem;
  bottom: 0.5rem;
  width: 3px;
  background: repeating-linear-gradient(to bottom, var(--about-navy) 0 12px, transparent 12px 20px);
}

@media (max-width: 767px) {
  .page-about__timeline::before {
    left: 5px;
  }
}

.page-about__timeline-item {
  position: relative;
  margin-bottom: 2.75rem;
  display: grid;
  grid-template-columns: 140px 1fr;
  gap: 2rem;
}

@media (max-width: 767px) {
  .page-about__timeline-item {
    grid-template-columns: 1fr;
    gap: 0.5rem;
  }
}

.page-about__timeline-item:last-child {
  margin-bottom: 0.25rem;
}

.page-about__timeline-item::before {
  content: "";
  position: absolute;
  left: calc(-2.5rem + 9px - 4px);
  top: 0.5rem;
  width: 11px;
  height: 11px;
  background: var(--about-orange);
  border: 2px solid var(--about-white);
  transform: rotate(45deg);
  z-index: 2;
}

@media (max-width: 767px) {
  .page-about__timeline-item::before {
    left: calc(-1.25rem + 5px - 4px);
  }
}

.page-about__timeline-year {
  text-align: right;
}

@media (max-width: 767px) {
  .page-about__timeline-year {
    text-align: left;
  }
}

.page-about__timeline-year-num {
  font-family: var(--font-display);
  font-size: 1.875rem;
  font-weight: 900;
  color: var(--about-navy);
  line-height: 1;
  letter-spacing: -0.02em;
}

@media (max-width: 767px) {
  .page-about__timeline-year-num {
    font-size: 1.375rem;
  }
}

.page-about__timeline-card {
  background: var(--about-light);
  border: 2px solid var(--about-navy);
  padding: 1.5rem 1.75rem;
  box-shadow: 6px 6px 0 rgba(10, 30, 63, 0.1);
  position: relative;
  transition: transform 0.2s ease, box-shadow 0.2s ease;
}

.page-about__timeline-card:hover {
  transform: translate(-2px, -2px);
  box-shadow: 8px 8px 0 rgba(10, 30, 63, 0.18);
}

.page-about__timeline-card-current {
  border-color: var(--about-orange);
}

.page-about__timeline-tag {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  background: var(--about-navy);
  color: var(--about-white);
  padding: 0.3rem 0.75rem;
  margin-bottom: 0.75rem;
}

.page-about__timeline-tag-orange {
  background: var(--about-orange);
  color: var(--about-navy);
  font-weight: 700;
}

.page-about__timeline-title {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 700;
  margin: 0 0 0.75rem;
}

.page-about__timeline-card p {
  font-size: 0.9375rem;
  line-height: 1.65;
  margin: 0;
  color: var(--about-text-secondary);
}

/* ============ architecture ============ */
.page-about__arch {
  background: var(--about-navy);
  color: var(--about-white);
  border-block: 3px solid var(--about-orange);
  position: relative;
  overflow: hidden;
}

.page-about__arch::before {
  content: "";
  position: absolute;
  top: -50%;
  left: -20%;
  width: 50%;
  height: 200%;
  background: rgba(255, 107, 53, 0.06);
  transform: rotate(20deg);
  pointer-events: none;
}

.page-about__arch .sec-title {
  color: var(--about-white);
}

.page-about__arch .sec-link {
  color: var(--about-orange);
}

.page-about__arch-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 3rem;
  align-items: start;
}

@media (max-width: 900px) {
  .page-about__arch-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
}

.page-about__arch-lead {
  font-family: var(--font-display);
  font-size: 1.375rem;
  font-weight: 600;
  line-height: 1.45;
  color: var(--about-white);
  margin-bottom: 1rem;
}

.page-about__arch-copy p {
  font-size: 1rem;
  line-height: 1.7;
  color: rgba(245, 247, 250, 0.85);
  margin-bottom: 1.5rem;
}

.page-about__arch-list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid rgba(255, 255, 255, 0.2);
}

.page-about__arch-list li {
  padding: 0.8rem 0 0.8rem 1.5rem;
  border-bottom: 1px solid rgba(255, 255, 255, 0.15);
  position: relative;
  font-size: 0.9375rem;
  line-height: 1.6;
  color: rgba(245, 247, 250, 0.8);
}

.page-about__arch-list li::before {
  content: "↗";
  position: absolute;
  left: 0;
  color: var(--about-orange);
  font-family: var(--font-mono);
}

.page-about__arch-list strong {
  color: var(--about-white);
  display: block;
  margin-bottom: 0.15rem;
}

.page-about__arch-stats {
  display: flex;
  flex-direction: column;
  gap: 1.25rem;
}

.page-about__arch-stat {
  background: rgba(255, 255, 255, 0.08);
  border: 2px solid rgba(255, 255, 255, 0.35);
  border-left: 6px solid var(--about-orange);
  padding: 1.5rem 1.25rem;
  box-shadow: 8px 8px 0 rgba(0, 0, 0, 0.25);
  backdrop-filter: blur(2px);
  transition: transform 0.25s ease, background 0.25s ease;
}

.page-about__arch-stat:hover {
  transform: translateX(4px);
  background: rgba(255, 107, 53, 0.12);
}

.page-about__arch-stat .stat-index {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--about-orange);
  display: block;
  margin-bottom: 0.5rem;
}

.page-about__arch-stat .stat-value {
  font-family: var(--font-mono);
  font-size: 2.25rem;
  font-weight: 700;
  color: var(--about-white);
  line-height: 1.2;
  margin-bottom: 0.35rem;
}

.page-about__arch-stat .stat-label {
  font-size: 0.875rem;
  color: rgba(245, 247, 250, 0.7);
  margin: 0;
}

.page-about__arch-visual {
  margin-top: 2.5rem;
  padding: 1.5rem;
  background: rgba(7, 20, 41, 0.8);
  border: 2px solid rgba(255, 255, 255, 0.2);
  overflow: hidden;
}

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

.page-about__arch-figure {
  margin: 2.5rem 0 0;
  border: 2px solid rgba(255, 255, 255, 0.3);
  box-shadow: 12px 12px 0 rgba(0, 0, 0, 0.3);
}

.page-about__arch-img {
  width: 100%;
  height: auto;
  display: block;
  aspect-ratio: 3 / 2;
  object-fit: cover;
}

/* ============ team & scale ============ */
.page-about__team {
  background: var(--about-light);
  position: relative;
}

.page-about__team-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 3.5rem;
  margin-bottom: 2.5rem;
}

@media (max-width: 900px) {
  .page-about__team-grid {
    grid-template-columns: 1fr;
    gap: 2rem;
  }
}

.page-about__team-copy p {
  font-size: 1rem;
  line-height: 1.7;
  margin-bottom: 1.75rem;
  color: var(--about-text-secondary);
}

.page-about__team-numbers {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1.25rem;
}

@media (max-width: 479px) {
  .page-about__team-numbers {
    grid-template-columns: repeat(3, 1fr);
    gap: 0.75rem;
  }
}

.page-about__team-num-block {
  border: 2px solid var(--about-navy);
  background: var(--about-white);
  padding: 1.5rem 0.75rem;
  text-align: center;
  box-shadow: 6px 6px 0 rgba(10, 30, 63, 0.12);
}

@media (max-width: 479px) {
  .page-about__team-num-block {
    padding: 1rem 0.5rem;
  }
}

.page-about__team-num {
  display: block;
  font-family: var(--font-mono);
  font-size: 2.75rem;
  font-weight: 700;
  line-height: 1;
  color: var(--about-navy);
}

@media (max-width: 479px) {
  .page-about__team-num {
    font-size: 1.75rem;
  }
}

.page-about__team-unit {
  font-size: 1rem;
  font-weight: 400;
  color: var(--about-orange);
  margin-left: 0.15rem;
}

@media (max-width: 479px) {
  .page-about__team-unit {
    font-size: 0.75rem;
  }
}

.page-about__team-label {
  display: block;
  font-size: 0.8125rem;
  color: var(--about-text-secondary);
  margin-top: 0.5rem;
}

@media (max-width: 479px) {
  .page-about__team-label {
    font-size: 0.6875rem;
  }
}

.page-about__team-scale {
  background: var(--about-white);
  border: 2px solid var(--about-navy);
  padding: 1.75rem 1.5rem;
  box-shadow: 10px 10px 0 rgba(10, 30, 63, 0.14);
}

.page-about__team-scale-title {
  font-family: var(--font-display);
  font-size: 1.125rem;
  font-weight: 700;
  margin: 0 0 1.25rem;
  padding-bottom: 0.75rem;
  border-bottom: 2px solid var(--about-navy);
}

.page-about__scale-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about__scale-list li {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  padding: 0.65rem 0;
  border-bottom: 1px solid var(--about-border);
}

.page-about__scale-label {
  font-size: 0.9375rem;
  color: var(--about-text-secondary);
}

.page-about__scale-count {
  font-family: var(--font-mono);
  font-size: 1.375rem;
  font-weight: 700;
  color: var(--about-navy);
}

.page-about__scale-unit {
  font-size: 0.875rem;
  color: var(--about-orange);
  margin-left: 0.1rem;
}

.page-about__team-figure {
  margin: 0 0 1.5rem;
  border: 2px solid var(--about-navy);
  box-shadow: var(--about-shadow);
}

.page-about__team-img {
  width: 100%;
  height: auto;
  display: block;
  aspect-ratio: 7 / 5;
  object-fit: cover;
}

.page-about__team-note {
  font-size: 0.875rem;
  text-align: center;
  max-width: 60ch;
  margin-inline: auto;
}

/* ============ ticker ============ */
.page-about__ticker-wrap {
  background: var(--about-navy-deep);
  border-top: 3px solid var(--about-orange);
  font-family: var(--font-mono);
  font-size: 0.875rem;
  color: rgba(245, 247, 250, 0.9);
  letter-spacing: 0.02em;
  overflow: hidden;
}

/* ============ motion ============ */
@media (prefers-reduced-motion: reduce) {
  .page-about .reveal,
  .page-about .reveal-left,
  .page-about .reveal-right {
    opacity: 1 !important;
    transform: none !important;
  }

  .page-about__timeline-card,
  .page-about__arch-stat {
    transition: none;
  }

  .page-about .ticker-track {
    animation: none !important;
    overflow-x: auto;
  }
}

@media (min-width: 768px) {
  .page-about .reveal-init {
    opacity: 0;
    transform: translateY(24px);
  }

  .page-about .reveal-init.reveal-left {
    transform: translateX(-24px);
  }

  .page-about .reveal-init.reveal-right {
    transform: translateX(24px);
  }

  .page-about .reveal-init.is-in {
    opacity: 1;
    transform: translate(0, 0);
    transition: opacity 0.55s var(--ease), transform 0.55s var(--ease);
    transition-delay: calc(var(--reveal-delay, 0) * 0.12s);
  }
}

@media (max-width: 767px) {
  .page-about .reveal {
    opacity: 1 !important;
    transform: none !important;
  }
}

.page-about {
  --reveal-delay: 0.3s;
}