.page-about {
  background: var(--paper-white);
  color: var(--ink-black);
  --about-deep: #12382c;
  --about-line-soft: #e4e0da;
  --about-panel: #ffffff;
}

.page-about .container {
  max-width: 1280px;
  margin-inline: auto;
  padding: 1.5rem 1.25rem 4rem;
}

.page-about .breadcrumbs {
  margin-bottom: 1.5rem;
  font-size: 0.8125rem;
  color: var(--text-gray);
  letter-spacing: 0.02em;
}

.page-about .breadcrumbs a {
  color: var(--pitch-green);
  font-weight: 500;
  text-decoration: none;
  transition: color 0.3s ease;
}

.page-about .breadcrumbs a:hover {
  color: var(--vital-orange);
}

.page-about .breadcrumbs-sep {
  margin: 0 0.5rem;
  color: var(--line-gray);
}

.page-about .about-header {
  margin-bottom: 2.5rem;
  padding-bottom: 2rem;
  border-bottom: 2px solid var(--line-gray);
  position: relative;
}

.page-about .about-header::after {
  content: '';
  position: absolute;
  left: 0;
  bottom: -2px;
  width: 96px;
  height: 4px;
  background: var(--vital-orange);
}

.page-about .page-kicker {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  color: var(--vital-orange);
  margin-bottom: 0.75rem;
}

.page-about .page-title {
  font-family: var(--font-heading);
  font-size: clamp(2rem, 5vw, 3.5rem);
  line-height: 1.08;
  letter-spacing: -0.01em;
  color: var(--pitch-green);
  margin-bottom: 0.75rem;
}

.page-about .page-title span {
  display: block;
  font-family: var(--font-body);
  font-size: 1.125rem;
  font-weight: 400;
  margin-top: 0.75rem;
  color: var(--text-gray);
  line-height: 1.5;
}

.page-about .page-intro {
  max-width: 38rem;
  color: var(--text-gray);
  font-size: 0.9375rem;
  line-height: 1.85;
  margin-top: 1.5rem;
}

.page-about .about-hero-image {
  background: var(--pitch-green);
  margin-bottom: 3.5rem;
}

.page-about .about-hero-image img {
  width: 100%;
  height: auto;
  display: block;
  margin-bottom: -28px;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 28px), 0 100%);
}

.page-about .about-section {
  position: relative;
  margin-bottom: 3.5rem;
  padding-top: 2rem;
  border-top: 2px solid var(--line-gray);
}

.page-about .about-section::after {
  content: '';
  position: absolute;
  top: -2px;
  left: 0;
  width: 64px;
  height: 4px;
  background: var(--vital-orange);
}

.page-about .section-heading {
  margin-bottom: 1.5rem;
}

.page-about .section-number {
  font-family: var(--font-mono);
  font-size: 2.5rem;
  line-height: 1;
  color: var(--vital-orange);
  display: inline-block;
  margin-right: 0.75rem;
}

.page-about .section-title {
  font-family: var(--font-heading);
  font-size: 1.75rem;
  line-height: 1.16;
  color: var(--pitch-green);
  letter-spacing: -0.01em;
  display: inline;
  margin: 0;
  vertical-align: middle;
}

.page-about .section-content {
  min-width: 0;
}

.page-about .split-layout {
  display: grid;
  gap: 1.5rem;
}

.page-about .aside-note {
  padding: 1rem 0 0 1rem;
  border-left: 3px solid var(--vital-orange);
  font-size: 0.875rem;
  line-height: 1.75;
  color: var(--text-gray);
}

.page-about .content-main {
  min-width: 0;
}

/* 01 品牌宣言 */
.page-about .about-manifesto-layout {
  display: grid;
  gap: 2rem;
}

.page-about .about-manifesto-text .about-lead {
  font-family: var(--font-heading);
  font-size: clamp(1.4rem, 3vw, 2rem);
  line-height: 1.35;
  color: var(--pitch-green);
  margin-bottom: 1rem;
}

.page-about .about-manifesto-text p {
  color: var(--text-gray);
  line-height: 1.85;
  font-size: 0.9375rem;
  margin-bottom: 1rem;
}

.page-about .about-manifesto-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.625rem;
  margin-top: 1.5rem;
}

.page-about .about-manifesto-tags a {
  text-decoration: none;
}

.page-about .about-facts {
  background: var(--pitch-green);
  padding: 1.5rem 1.375rem;
  margin: 0;
  position: relative;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 22px), 0 100%);
}

.page-about .fact-item {
  padding: 1rem 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.18);
}

.page-about .fact-item:last-child {
  border-bottom: none;
  padding-bottom: 0.25rem;
}

.page-about .fact-item dt {
  font-family: var(--font-mono);
  font-size: 2.25rem;
  line-height: 1.1;
  color: var(--vital-orange);
  font-weight: 500;
}

.page-about .fact-item dd {
  margin: 0.375rem 0 0;
  font-size: 0.875rem;
  line-height: 1.6;
  color: rgba(255, 255, 255, 0.78);
}

/* 02 发展历程 */
.page-about .timeline-map {
  width: 100%;
  height: auto;
  display: block;
  margin-bottom: 2rem;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 18px), 0 100%);
}

.page-about .about-timeline {
  list-style: none;
  margin: 0 0 0 0.5rem;
  padding: 0 0 0 1.25rem;
  border-left: 2px solid var(--pitch-green);
}

.page-about .timeline-item {
  position: relative;
  padding: 0 0 2rem 0.25rem;
}

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

.page-about .timeline-item::before {
  content: '';
  position: absolute;
  left: -1.42rem;
  top: 0.375rem;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--paper-white);
  border: 3px solid var(--vital-orange);
  transition: background 0.3s ease;
}

.page-about .timeline-item:hover::before,
.page-about .timeline-item:focus-within::before {
  background: var(--vital-orange);
}

.page-about .timeline-year {
  font-family: var(--font-mono);
  font-size: 0.9375rem;
  letter-spacing: 0.08em;
  color: var(--vital-orange);
  font-weight: 600;
  display: inline-block;
  margin-bottom: 0.5rem;
}

.page-about .timeline-detail h3 {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  color: var(--pitch-green);
  margin-bottom: 0.375rem;
  line-height: 1.3;
}

.page-about .timeline-detail p {
  font-size: 0.9375rem;
  color: var(--text-gray);
  line-height: 1.75;
  max-width: 34rem;
}

/* 03 团队概况 */
.page-about .about-team-layout {
  display: grid;
  gap: 1.5rem;
}

.page-about .about-team-image img {
  width: 100%;
  height: auto;
  display: block;
  margin-bottom: -14px;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 14px), 0 100%);
}

.page-about .team-bars {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1rem;
}

.page-about .team-bar {
  display: grid;
  grid-template-columns: 5.5rem 1fr 3rem;
  align-items: center;
  gap: 0.75rem;
}

.page-about .team-bar-name {
  font-weight: 600;
  font-size: 0.875rem;
  color: var(--ink-black);
}

.page-about .team-bar-track {
  display: block;
  height: 14px;
  background: #e9ede9;
  border: 1px solid var(--line-gray);
  overflow: hidden;
}

.page-about .team-bar-fill {
  display: block;
  height: 100%;
  background: var(--pitch-green);
}

.page-about .team-bar--tech .team-bar-fill {
  width: 40%;
}

.page-about .team-bar--data .team-bar-fill {
  width: 30%;
  background: var(--wine-red);
}

.page-about .team-bar--content .team-bar-fill {
  width: 20%;
  background: var(--royal-purple);
}

.page-about .team-bar--ops .team-bar-fill {
  width: 10%;
  background: var(--vital-orange);
}

.page-about .team-bar-count {
  font-family: var(--font-mono);
  font-size: 0.875rem;
  color: var(--text-gray);
  text-align: right;
}

.page-about .team-desc {
  margin-top: 1.5rem;
  padding: 1rem 1.25rem;
  border-left: 3px solid var(--vital-orange);
  background: var(--about-panel);
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--text-gray);
}

/* 04 技术架构 */
.page-about .tech-lead {
  font-family: var(--font-heading);
  font-size: 1.125rem;
  line-height: 1.5;
  color: var(--pitch-green);
  margin-bottom: 1.5rem;
  max-width: 36rem;
}

.page-about .tech-diagram {
  background: var(--ink-black);
  padding: 1.5rem 1rem;
  margin: 0 0 1.75rem;
  overflow: hidden;
}

.page-about .tech-svg {
  width: 100%;
  height: auto;
  display: block;
  min-width: 620px;
}

.page-about .tech-node {
  fill: var(--pitch-green);
  stroke: var(--vital-orange);
  stroke-width: 1.5;
}

.page-about .tech-node-title {
  fill: #ffffff;
  font-family: var(--font-heading);
  font-size: 16px;
  font-weight: 400;
}

.page-about .tech-node-sub {
  fill: #c9d6d1;
  font-family: var(--font-body);
  font-size: 11px;
}

.page-about .tech-arrow {
  fill: none;
  stroke: var(--vital-orange);
  stroke-width: 2;
}

.page-about .tech-points {
  display: grid;
  gap: 1.25rem;
  margin: 0;
}

.page-about .tech-point {
  padding: 1.25rem;
  background: var(--about-panel);
  border: 1px solid var(--line-gray);
  position: relative;
}

.page-about .tech-point::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 5px;
  height: 100%;
  background: var(--pitch-green);
}

.page-about .tech-point:nth-child(2)::before {
  background: var(--wine-red);
}

.page-about .tech-point:nth-child(3)::before {
  background: var(--royal-purple);
}

.page-about .tech-point dt {
  font-family: var(--font-heading);
  font-size: 1.0625rem;
  color: var(--pitch-green);
  margin-bottom: 0.5rem;
}

.page-about .tech-point dd {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--text-gray);
}

/* 05 合作与认证 */
.page-about .partners-grid {
  display: grid;
  gap: 1.25rem;
}

.page-about .partner-card {
  background: var(--about-panel);
  border: 1px solid var(--line-gray);
  padding: 1.5rem 1.375rem 1.75rem;
  position: relative;
  transition: border-color 0.3s ease, transform 0.3s ease;
}

.page-about .partner-card:hover {
  border-color: var(--vital-orange);
  transform: translateX(6px);
}

.page-about .partner-kicker {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--vital-orange);
  margin-bottom: 0.625rem;
}

.page-about .partner-card h3 {
  font-family: var(--font-heading);
  font-size: 1.125rem;
  line-height: 1.3;
  color: var(--pitch-green);
  margin-bottom: 0.625rem;
}

.page-about .partner-card p {
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--text-gray);
}

.page-about .partners-note {
  margin-top: 1.5rem;
  font-size: 0.875rem;
  color: var(--text-gray);
  line-height: 1.7;
  border-left: 3px solid var(--vital-orange);
  padding-left: 1rem;
}

/* 06 联系与加入 */
.page-about .about-contact-layout {
  display: grid;
  gap: 2rem;
}

.page-about .contact-lead {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  line-height: 1.5;
  color: var(--pitch-green);
  margin-bottom: 1.25rem;
}

.page-about .about-address {
  font-style: normal;
  font-size: 0.9375rem;
  line-height: 2.1;
  color: var(--ink-black);
  margin-bottom: 1.5rem;
  padding: 1.25rem 1.375rem;
  background: var(--about-panel);
  border: 1px solid var(--line-gray);
}

.page-about .about-join {
  background: var(--pitch-green);
  color: #ffffff;
  padding: 2rem 1.75rem;
  position: relative;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 24px), 0 100%);
}

.page-about .about-join h3 {
  font-family: var(--font-heading);
  font-size: 1.25rem;
  color: #ffffff;
  margin-bottom: 0.75rem;
}

.page-about .about-join p {
  font-size: 0.9375rem;
  line-height: 1.8;
  color: rgba(255, 255, 255, 0.8);
  margin-bottom: 1.25rem;
}

.page-about .about-join .btn-ghost {
  border-color: rgba(255, 255, 255, 0.7);
  color: #ffffff;
}

.page-about .about-join .btn-ghost:hover {
  background: rgba(255, 255, 255, 0.12);
  color: #ffffff;
}

/* 响应式增强 */
@media (min-width: 40rem) {
  .page-about .container {
    padding: 2rem 2rem 5rem;
  }

  .page-about .about-header {
    display: grid;
    grid-template-columns: 1.25fr 0.75fr;
    gap: 2.5rem;
    align-items: end;
  }

  .page-about .page-intro {
    margin-top: 0;
    border-left: 3px solid var(--vital-orange);
    padding-left: 1.25rem;
  }

  .page-about .about-section {
    display: grid;
    grid-template-columns: clamp(8rem, 24%, 12rem) 1fr;
    gap: 1.5rem 2.5rem;
    align-items: start;
  }

  .page-about .section-heading {
    margin-bottom: 0;
  }

  .page-about .section-number {
    display: block;
    margin-bottom: 0.5rem;
    font-size: 3rem;
  }

  .page-about .section-title {
    display: block;
    font-size: 2rem;
  }

  .page-about .about-manifesto-layout {
    grid-template-columns: 1.35fr 0.65fr;
    gap: 2.5rem;
    align-items: start;
  }

  .page-about .about-facts {
    padding: 1.75rem 1.5rem;
  }

  .page-about .split-layout {
    grid-template-columns: minmax(8rem, 22%) 1fr;
    gap: 2rem;
  }

  .page-about .aside-note {
    padding-left: 1.25rem;
  }

  .page-about .about-team-layout {
    grid-template-columns: 1.1fr 0.9fr;
    gap: 2rem;
  }

  .page-about .tech-diagram {
    padding: 2rem 1.5rem;
  }

  .page-about .tech-points {
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
  }

  .page-about .partners-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
  }

  .page-about .about-contact-layout {
    grid-template-columns: 1.1fr 0.9fr;
    align-items: stretch;
  }
}

@media (min-width: 64rem) {
  .page-about .page-title {
    font-size: 3.5rem;
  }

  .page-about .about-section {
    gap: 1.5rem 3.5rem;
  }

  .page-about .about-section:nth-of-type(even) {
    grid-template-columns: 1fr clamp(8rem, 24%, 12rem);
  }

  .page-about .about-section:nth-of-type(even) .section-heading {
    grid-column: 2;
    grid-row: 1;
  }

  .page-about .about-section:nth-of-type(even) .section-content {
    grid-column: 1;
    grid-row: 1;
  }

  .page-about .about-section:nth-of-type(even)::after {
    left: auto;
    right: 0;
  }

  .page-about .about-section:nth-of-type(even) .aside-note {
    border-left: none;
    border-right: 3px solid var(--vital-orange);
    padding-left: 0;
    padding-right: 1.25rem;
    text-align: right;
  }

  .page-about .timeline-map {
    max-width: 560px;
  }

  .page-about .tech-svg {
    min-width: 0;
  }

  .page-about .about-join {
    padding: 2.5rem 2rem;
  }
}