.page-about {
  --about-line: rgba(242, 183, 5, 0.55);
  --about-line-soft: rgba(242, 183, 5, 0.18);
  --about-red-edge: #8B0000;
  --about-deep: #082E23;
  --about-muted: #5C6B5C;
  --about-cream: #F5F5F0;
  --about-num-color: #D4A017;
  --about-rail-w: 292px;
  --about-gap: 48px;
  background:
    linear-gradient(180deg,
      rgba(11, 61, 46, 0.05) 0%,
      rgba(11, 61, 46, 0) 240px),
    var(--about-cream);
  color: #16261C;
  padding: clamp(24px, 4vw, 56px) clamp(18px, 5vw, 72px) 72px;
  line-height: 1.6;
}

.page-about__breadcrumb {
  margin-bottom: 28px;
  font-size: 13px;
  letter-spacing: 0.02em;
}

.page-about__breadcrumb .breadcrumb__item {
  color: var(--about-muted);
}

.page-about__breadcrumb .breadcrumb__item:not(:last-child)::after {
  content: "→";
  margin: 0 8px;
  color: var(--color-gold);
  font-family: var(--font-mono);
}

.page-about__breadcrumb .breadcrumb__item[aria-current="page"] {
  color: var(--color-pitch);
  font-weight: 600;
}

.page-about__hero {
  position: relative;
  display: grid;
  gap: 28px;
  margin-bottom: 48px;
  background: var(--color-pitch);
  border-radius: 28px;
  padding: clamp(24px, 4vw, 48px);
  overflow: hidden;
  box-shadow: 0 18px 50px rgba(8, 46, 35, 0.14);
}

.page-about__hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background:
    linear-gradient(115deg, transparent 0%, transparent 62%, rgba(242, 183, 5, 0.08) 62.5%, rgba(242, 183, 5, 0.08) 78%, transparent 78.5%),
    linear-gradient(115deg, transparent 82%, rgba(0, 209, 255, 0.07) 82.5%, rgba(0, 209, 255, 0.07) 92%, transparent 92.5%);
  pointer-events: none;
}

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

.page-about__title {
  margin: 10px 0 16px;
  font-family: var(--font-display);
  font-size: clamp(28px, 4vw, 52px);
  line-height: 1.15;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: #F5F5F0;
  text-wrap: balance;
}

.page-about__lead {
  margin: 0 0 22px;
  color: rgba(245, 245, 240, 0.88);
  font-size: clamp(15px, 1.4vw, 17px);
  max-width: 36em;
}

.page-about__hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-bottom: 20px;
}

.page-about__cta {
  display: inline-flex;
}

.page-about__hero-image {
  position: relative;
  z-index: 1;
  max-width: 100%;
}

.page-about__hero-image::after {
  content: "";
  position: absolute;
  right: -12px;
  bottom: -12px;
  width: 90px;
  height: 90px;
  background: radial-gradient(circle at center, rgba(242, 183, 5, 0.3) 0%, transparent 70%);
  z-index: 0;
}

.page-about__hero-image img,
.page-about__data-image img,
.page-about__eco-image img {
  width: 100%;
  height: auto;
  display: block;
  object-fit: cover;
  border-radius: var(--radius-md);
}

.page-about__hero-image img {
  border: 1px solid rgba(242, 183, 5, 0.35);
}

.page-about__layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 40px;
  align-items: start;
}

.page-about__timeline-rail {
  display: none;
}

.page-about__content {
  min-width: 0;
}

.page-about-block {
  margin-bottom: 56px;
}

.page-about__milestone-section {
  scroll-margin-top: 40px;
}

.page-about__milestone-card {
  position: relative;
  background: var(--about-cream);
  border-radius: 20px;
  padding: 28px 26px 30px;
  margin-bottom: 28px;
  border: 1px solid rgba(92, 107, 92, 0.24);
  border-left: 4px solid var(--about-red-edge);
  box-shadow: 0 6px 20px rgba(8, 46, 35, 0.07);
  transition: transform 0.3s cubic-bezier(0.2, 0.9, 0.4, 1), box-shadow 0.3s cubic-bezier(0.2, 0.9, 0.4, 1);
  scroll-margin-top: 40px;
}

.page-about__milestone-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 12px 30px rgba(8, 46, 35, 0.12);
}

.page-about__milestone-card--current {
  background: var(--color-pitch);
  border-left-color: var(--color-gold);
  color: rgba(245, 245, 240, 0.92);
}

.page-about__milestone-card--current .page-about__milestone-head {
  border-bottom-color: rgba(242, 183, 5, 0.25);
}

.page-about__milestone-card--current .section-title {
  color: #F5F5F0;
}

.page-about__milestone-card--current p {
  color: rgba(245, 245, 240, 0.85);
}

.page-about__milestone-head {
  display: flex;
  align-items: center;
  gap: 12px;
  flex-wrap: wrap;
  padding-bottom: 12px;
  margin-bottom: 14px;
  border-bottom: 1px solid rgba(92, 107, 92, 0.18);
}

.page-about__milestone-year {
  font-family: var(--font-display);
  font-size: 32px;
  font-weight: 800;
  letter-spacing: 0.02em;
  color: var(--color-pitch);
  line-height: 1;
}

.page-about__milestone-card--current .page-about__milestone-year {
  color: var(--color-gold);
}

.page-about__milestone-card p {
  margin-bottom: 1em;
}

.page-about__milestone-card p:last-child {
  margin-bottom: 0;
}

.page-about__btn {
  margin-top: 18px;
  color: var(--color-pitch);
  border-color: var(--color-pitch);
}

.page-about__btn:hover {
  background: var(--color-pitch);
  border-color: var(--color-pitch);
}

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

.page-about__section-head .page-about__section-title,
.page-about__section-head .section-title {
  font-family: var(--font-display);
  font-size: clamp(22px, 2.6vw, 34px);
  font-weight: 800;
  margin: 8px 0 10px;
  letter-spacing: -0.01em;
  color: var(--color-pitch);
}

.page-about__section-head .section-lead {
  color: var(--about-muted);
  font-size: 15px;
}

.page-about__stats-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  margin-bottom: 32px;
}

.page-about__stat-card {
  background: var(--color-pitch);
  border-radius: 18px;
  padding: 24px 22px;
  position: relative;
  overflow: hidden;
  color: #F5F5F0;
  display: flex;
  flex-direction: column;
  gap: 4px;
  border: 1px solid rgba(242, 183, 5, 0.18);
}

.page-about__stat-card::before {
  content: "";
  position: absolute;
  right: -30px;
  top: -30px;
  width: 100px;
  height: 100px;
  background: rgba(242, 183, 5, 0.08);
  border-radius: 50%;
}

.page-about__stat-num {
  font-family: var(--font-mono);
  font-size: clamp(32px, 4vw, 40px);
  font-weight: 600;
  color: var(--color-gold);
  line-height: 1.05;
  letter-spacing: -0.02em;
}

.page-about__stat-label {
  font-weight: 600;
  font-size: 16px;
  margin-top: 6px;
}

.page-about__stat-desc {
  font-size: 13px;
  color: rgba(245, 245, 240, 0.72);
}

.page-about__data-image {
  max-width: 100%;
  margin-top: 4px;
}

.page-about__data-image img {
  border: 1px solid rgba(11, 61, 46, 0.12);
}

.page-about__ecosystem-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  margin-bottom: 28px;
}

.page-about__eco-card {
  background: #FFFFFF;
  border-radius: 16px;
  padding: 22px 20px;
  border: 1px solid rgba(92, 107, 92, 0.14);
  border-top: 3px solid var(--color-gold);
  box-shadow: 0 3px 12px rgba(8, 46, 35, 0.04);
  transition: transform 0.3s cubic-bezier(0.2, 0.9, 0.4, 1), box-shadow 0.3s cubic-bezier(0.2, 0.9, 0.4, 1);
}

.page-about__eco-card:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(8, 46, 35, 0.09);
}

.page-about__eco-index {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--about-num-color);
  font-weight: 600;
  margin-bottom: 8px;
  letter-spacing: 0.06em;
}

.page-about__eco-title {
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 700;
  color: var(--color-pitch);
  margin-bottom: 8px;
  letter-spacing: -0.01em;
}

.page-about__eco-card p {
  color: var(--about-muted);
  font-size: 14px;
  line-height: 1.6;
  margin: 0;
}

.page-about__eco-image {
  max-width: 100%;
}

.page-about__eco-image img {
  width: 100%;
  max-height: 300px;
  object-fit: cover;
  border: 1px solid rgba(11, 61, 46, 0.12);
  border-radius: 18px;
}

.page-about__community-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
}

.page-about__community-copy {
  background: var(--color-pitch);
  color: rgba(245, 245, 240, 0.88);
  border-radius: 20px;
  padding: 24px;
  font-size: 15px;
}

.page-about__community-copy p {
  margin-bottom: 16px;
}

.page-about__community-copy p:last-child {
  margin-bottom: 0;
}

.page-about__quote {
  margin: 20px 0 0;
  padding: 16px 18px 16px 18px;
  background: rgba(242, 183, 5, 0.09);
  border-left: 3px solid var(--color-gold);
  border-radius: 0 12px 12px 0;
  color: #F5F5F0;
}

.page-about__quote p {
  margin: 0;
  font-family: var(--font-display);
  font-size: 17px;
  line-height: 1.5;
  font-weight: 500;
  letter-spacing: 0.02em;
}

.page-about__community-list {
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.page-about__community-item {
  display: flex;
  align-items: flex-start;
  gap: 18px;
  padding: 18px 20px;
  background: #FFFFFF;
  border-radius: 16px;
  border: 1px solid rgba(92, 107, 92, 0.14);
  border-bottom: 2px solid rgba(242, 183, 5, 0.4);
}

.page-about__community-num {
  font-family: var(--font-mono);
  font-size: 26px;
  font-weight: 600;
  color: var(--about-num-color);
  min-width: 70px;
  white-space: nowrap;
}

.page-about__community-item strong {
  display: block;
  color: var(--color-pitch);
  font-size: 15px;
  margin-bottom: 4px;
}

.page-about__community-item span:last-child {
  color: var(--about-muted);
  font-size: 13px;
  line-height: 1.5;
}

.page-about__quality-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 26px;
}

.page-about__quality-desc {
  background: var(--color-pitch);
  color: rgba(245, 245, 240, 0.86);
  padding: 24px;
  border-radius: 18px;
  font-size: 15px;
}

.page-about__quality-desc p {
  margin-bottom: 14px;
}

.page-about__quality-desc p:last-child {
  margin-bottom: 0;
}

.page-about__quality-process {
  background: #FFFFFF;
  border-radius: 18px;
  padding: 24px;
  border: 1px solid rgba(92, 107, 92, 0.16);
}

.page-about__quality-title {
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 700;
  color: var(--color-pitch);
  margin-bottom: 18px;
  letter-spacing: -0.01em;
}

.page-about__quality-steps {
  list-style: none;
  counter-reset: step;
  margin: 0;
  padding: 0;
}

.page-about__quality-steps li {
  position: relative;
  counter-increment: step;
  padding-left: 48px;
  padding-bottom: 16px;
  margin-bottom: 12px;
  border-bottom: 1px dashed rgba(92, 107, 92, 0.2);
}

.page-about__quality-steps li:last-child {
  padding-bottom: 0;
  margin-bottom: 0;
  border-bottom: 0;
}

.page-about__quality-steps li::before {
  content: counter(step, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: -2px;
  width: 32px;
  height: 32px;
  background: var(--color-pitch);
  color: var(--color-gold);
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 600;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  letter-spacing: 0.02em;
}

.page-about__quality-steps li strong {
  display: block;
  color: var(--color-pitch);
  font-size: 14px;
  margin-bottom: 3px;
}

.page-about__quality-steps li span {
  color: var(--about-muted);
  font-size: 13px;
  line-height: 1.5;
}

.page-about__trust-band {
  margin-top: 26px;
  background: rgba(242, 183, 5, 0.1);
  border: 1px solid rgba(212, 160, 23, 0.35);
  border-radius: 16px;
  padding: 18px 20px;
  font-size: 14px;
  color: var(--color-pitch);
  line-height: 1.7;
}

.page-about__trust-band p {
  margin: 0 0 8px;
}

.page-about__trust-band p:last-child {
  margin-bottom: 0;
  color: var(--about-muted);
  font-size: 13px;
}

.page-about__trust-band a {
  color: var(--color-red);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about__milestone-note {
  background: var(--color-pitch);
  border-radius: 22px;
  padding: clamp(24px, 4vw, 44px);
  color: rgba(245, 245, 240, 0.9);
  position: relative;
  overflow: hidden;
}

.page-about__milestone-note::before {
  content: "";
  position: absolute;
  right: -40px;
  bottom: -40px;
  width: 180px;
  height: 180px;
  background: radial-gradient(circle at center, rgba(242, 183, 5, 0.16) 0%, transparent 68%);
  border-radius: 50%;
}

.page-about__milestone-note .section-kicker {
  color: var(--color-gold);
}

.page-about__milestone-note-inner {
  position: relative;
  z-index: 1;
}

.page-about__milestone-note .section-title {
  color: #F5F5F0;
  font-size: clamp(22px, 3vw, 32px);
  margin: 8px 0 14px;
}

.page-about__milestone-note p {
  max-width: 34em;
  font-size: 15px;
  line-height: 1.7;
}

.page-about__note-links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 24px;
}

.page-about__note-links .btn--light {
  color: var(--color-pitch);
}

.page-about__note-links .btn--outline {
  border-color: rgba(242, 183, 5, 0.7);
  color: var(--color-gold);
}

.page-about__note-links .btn--outline:hover {
  background: rgba(242, 183, 5, 0.14);
  border-color: var(--color-gold);
}

.page-about__link {
  color: var(--color-pitch);
  text-decoration: underline;
  text-underline-offset: 3px;
  font-weight: 600;
}

.page-about__link:hover {
  color: var(--color-red);
}

/* 响应式：平板以上 */
@media (min-width: 768px) {
  .page-about {
    padding-left: 36px;
    padding-right: 36px;
  }

  .page-about__hero {
    grid-template-columns: 1.15fr 0.85fr;
    align-items: center;
  }

  .page-about__hero-image {
    margin-left: 8px;
  }

  .page-about__stats-grid {
    grid-template-columns: repeat(2, 1fr);
  }

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

  .page-about__quality-layout {
    grid-template-columns: 1fr 1fr;
    gap: 20px;
  }

  .page-about__community-item {
    padding: 20px 22px;
  }
}

/* 响应式：桌面宽屏 */
@media (min-width: 1180px) {
  .page-about {
    padding-left: 64px;
    padding-right: 64px;
  }

  .page-about__layout {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: var(--about-gap);
  }

  .page-about__timeline-rail {
    display: block;
    position: sticky;
    top: 32px;
  }

  .page-about__rail-inner {
    background: var(--color-pitch);
    border-radius: 18px;
    padding: 24px 20px;
    box-shadow: 0 10px 30px rgba(8, 46, 35, 0.16);
    border: 1px solid rgba(242, 183, 5, 0.14);
  }

  .page-about__rail-label {
    color: var(--color-gold);
    font-size: 13px;
    margin-bottom: 18px;
    letter-spacing: 0.08em;
  }

  .page-about__rail-list {
    list-style: none;
    margin: 0 0 22px;
    padding: 0;
  }

  .page-about__rail-list li {
    position: relative;
  }

  .page-about__rail-list a {
    display: block;
    color: rgba(245, 245, 240, 0.78);
    text-decoration: none;
    padding: 9px 6px 9px 22px;
    border-left: 2px solid rgba(242, 183, 5, 0.25);
    transition: color 0.2s ease, border-color 0.2s ease, background 0.2s ease;
    border-radius: 0 8px 8px 0;
    font-size: 14px;
  }

  .page-about__rail-list a:hover {
    color: var(--color-gold);
    border-left-color: var(--color-gold);
    background: rgba(242, 183, 5, 0.06);
  }

  .page-about__rail-trust {
    color: rgba(245, 245, 240, 0.52);
    font-size: 12px;
    line-height: 1.55;
    padding: 18px 4px 0;
    border-top: 1px solid rgba(242, 183, 5, 0.15);
    margin-top: 4px;
  }

  .page-about__content {
    padding-top: 0;
  }

  .page-about__milestone-card {
    padding: 30px 30px 32px;
  }

  .page-about__eco-kv {
    grid-template-columns: 1fr 1fr;
  }

  .page-about__community-layout {
    grid-template-columns: 1.2fr 0.8fr;
    gap: 32px;
    align-items: stretch;
  }

  .page-about__quality-desc,
  .page-about__quality-process {
    padding: 28px;
  }

  .page-about__trust-band {
    padding: 20px 26px;
  }
}

/* 辅助显示 */
.page-about__visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  overflow: hidden;
  clip: rect(0 0 0 0);
  white-space: nowrap;
}