.page-about {
  --travel: 40px;
  background: var(--bsp-bg-deep);
  color: var(--bsp-text-main);
  font-family: var(--bsp-font-body);
  line-height: 1.6;
  overflow-x: clip;
}

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

/* 英雄区 */
.page-about__hero {
  position: relative;
  padding: 56px 0 72px;
  background:
    radial-gradient(ellipse at 78% 18%, rgba(0, 191, 255, 0.10), transparent 52%),
    linear-gradient(var(--bsp-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--bsp-line) 1px, transparent 1px);
  background-size: auto, 56px 56px, 56px 56px;
}

.page-about__hero::before {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 140px;
  height: 6px;
  background: linear-gradient(90deg, var(--bsp-green), var(--bsp-orange));
  z-index: 2;
}

.page-about__hero-inner {
  display: grid;
  gap: 40px;
  align-items: center;
  position: relative;
}

.page-about__eyebrow {
  margin: 0 0 16px;
  font-family: var(--bsp-font-head);
  font-size: 14px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--bsp-green);
}

.page-about__hero h1 {
  margin: 0 0 20px;
  font-family: var(--bsp-font-head);
  font-weight: 900;
  font-size: 42px;
  line-height: 1.08;
  letter-spacing: 0.01em;
  text-transform: uppercase;
}

.page-about__lede {
  margin: 0;
  max-width: 560px;
  color: var(--bsp-text-muted);
  font-size: 16px;
}

.page-about__hero-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 16px;
  margin: 36px 0 0;
  padding: 24px 0 0;
  border-top: 1px solid var(--bsp-line);
}

.page-about__hero-stats div {
  min-width: 0;
}

.page-about__hero-stats dt {
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--bsp-text-muted);
  text-transform: uppercase;
  margin: 0 0 6px;
}

.page-about__hero-stats dd {
  margin: 0;
  font-family: var(--bsp-font-head);
  font-size: 26px;
  line-height: 1;
  white-space: nowrap;
}

.page-about__hero-stats strong {
  color: var(--bsp-green);
  font-weight: 900;
}

.page-about__hero-figure {
  margin: 0;
  position: relative;
}

.page-about__hero-figure img {
  display: block;
  width: 100%;
  height: auto;
  max-width: 600px;
  margin-inline: auto;
  border: 1px solid var(--bsp-line);
  background: var(--bsp-bg-card);
}

.page-about__hero-figure::after {
  content: "";
  position: absolute;
  left: -12px;
  bottom: -12px;
  width: 64%;
  height: 3px;
  background: linear-gradient(90deg, var(--bsp-orange), var(--bsp-green));
  opacity: 0.85;
  z-index: 1;
}

/* 目录 */
.page-about__toc {
  position: sticky;
  top: 72px;
  z-index: 30;
  background: rgba(10, 31, 68, 0.92);
  -webkit-backdrop-filter: blur(6px);
  backdrop-filter: blur(6px);
  border-top: 1px solid var(--bsp-line);
  border-bottom: 1px solid var(--bsp-line);
}

.page-about__toc-inner {
  display: flex;
  align-items: center;
  gap: 16px;
  padding-top: 12px;
  padding-bottom: 12px;
}

.page-about__toc-label {
  font-family: var(--bsp-font-head);
  font-size: 14px;
  letter-spacing: 0.12em;
  color: var(--bsp-green);
  text-transform: uppercase;
  white-space: nowrap;
}

.page-about__toc-list {
  display: flex;
  gap: 8px 24px;
  margin: 0;
  padding: 0;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: none;
}

.page-about__toc-list::-webkit-scrollbar {
  display: none;
}

.page-about__toc-list a {
  display: inline-block;
  padding: 6px 0;
  color: var(--bsp-text-muted);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.03em;
  text-decoration: none;
  border-bottom: 2px solid transparent;
  transition: color 0.25s ease, border-color 0.25s ease;
  white-space: nowrap;
}

.page-about__toc-list a:hover,
.page-about__toc-list a:focus-visible {
  color: var(--bsp-green);
  border-bottom-color: var(--bsp-green);
  outline: none;
}

/* 通用章节 */
.page-about__section {
  position: relative;
  padding: 72px 0;
  scroll-margin-top: 130px;
  border-top: 1px solid var(--bsp-line);
}

.page-about__section::before {
  content: "";
  position: absolute;
  top: -1px;
  left: 0;
  width: 140px;
  height: 4px;
  background: linear-gradient(90deg, var(--bsp-green), var(--bsp-orange));
}

.page-about__section-index {
  margin: 0 0 12px;
  font-family: var(--bsp-font-head);
  font-size: 14px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--bsp-green);
}

.page-about__section h2 {
  margin: 0 0 16px;
  font-family: var(--bsp-font-head);
  font-weight: 900;
  font-size: 34px;
  line-height: 1.1;
  text-transform: uppercase;
  letter-spacing: 0.01em;
}

.page-about__section-lead {
  margin: 0 0 32px;
  color: var(--bsp-text-muted);
  font-size: 16px;
  max-width: 640px;
}

/* 使命 */
.page-about__mission-grid {
  display: grid;
  gap: 40px;
}

.page-about__mission-copy {
  max-width: 640px;
}

.page-about__mission-lead {
  margin: 0 0 16px;
  font-size: 19px;
  line-height: 1.5;
  color: var(--bsp-text-main);
}

.page-about__mission-copy p {
  margin: 0 0 16px;
  color: var(--bsp-text-muted);
}

.page-about__mission-points {
  list-style: none;
  margin: 28px 0 0;
  padding: 24px 0 0;
  border-top: 1px solid var(--bsp-line);
  display: grid;
  gap: 12px;
}

.page-about__mission-points li {
  position: relative;
  padding-left: 28px;
  color: var(--bsp-text-main);
  font-size: 15px;
}

.page-about__mission-points li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.55em;
  width: 16px;
  height: 2px;
  background: var(--bsp-green);
}

.page-about__mission-figure {
  margin: 0;
}

.page-about__mission-figure img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--bsp-line);
  background: var(--bsp-bg-card);
}

.page-about__mission-figure figcaption {
  margin-top: 12px;
  padding-left: 14px;
  border-left: 3px solid var(--bsp-orange);
  color: var(--bsp-text-muted);
  font-size: 14px;
}

/* 时间轴 */
.page-about__timeline {
  list-style: none;
  margin: 48px 0 0;
  padding: 0;
}

.page-about__timeline-item {
  --travel: 40px;
  display: grid;
  grid-template-columns: 28px 1fr;
  gap: 18px 16px;
  padding-bottom: var(--travel);
}

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

.page-about__timeline-year {
  grid-column: 1 / -1;
  font-family: var(--bsp-font-head);
  font-size: 34px;
  line-height: 1;
  color: var(--bsp-green);
}

.page-about__timeline-rail {
  position: relative;
}

.page-about__timeline-rail::before {
  content: "";
  position: absolute;
  top: 10px;
  bottom: calc(-1 * var(--travel));
  left: 50%;
  width: 2px;
  background: linear-gradient(180deg, var(--bsp-green), var(--bsp-line));
  transform: translateX(-50%);
}

.page-about__timeline-item:last-child .page-about__timeline-rail::before {
  display: none;
}

.page-about__timeline-dot {
  display: block;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--bsp-green);
  box-shadow: 0 0 0 4px rgba(57, 255, 20, 0.15), 0 0 18px rgba(57, 255, 20, 0.45);
}

.page-about__timeline-card {
  padding: 22px 24px;
  background: var(--bsp-bg-card);
  border: 1px solid var(--bsp-line);
  border-left: 3px solid var(--bsp-green);
  box-shadow: 0 12px 28px rgba(0, 0, 0, 0.18);
  transition: transform 0.25s ease, border-color 0.25s ease;
}

.page-about__timeline-card:hover {
  transform: translateX(4px);
  border-color: rgba(57, 255, 20, 0.45);
}

.page-about__timeline-card h3 {
  margin: 0 0 6px;
  font-family: var(--bsp-font-head);
  font-size: 20px;
  line-height: 1.2;
}

.page-about__timeline-card p {
  margin: 0;
  color: var(--bsp-text-muted);
  font-size: 15px;
}

/* 技术 */
.page-about__section--tech {
  background: var(--bsp-bg-navy);
}

.page-about__tech-grid {
  display: grid;
  gap: 40px;
  align-items: center;
}

.page-about__tech-figure {
  margin: 0;
}

.page-about__tech-figure img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--bsp-line);
  background: var(--bsp-bg-card);
}

.page-about__tech-figure figcaption {
  margin-top: 12px;
  padding-left: 14px;
  border-left: 3px solid var(--bsp-orange);
  color: var(--bsp-text-muted);
  font-size: 14px;
}

.page-about__tech-list {
  display: grid;
  gap: 16px;
}

.page-about__tech-item {
  display: grid;
  grid-template-columns: 48px 1fr;
  gap: 16px;
  padding: 20px;
  background: var(--bsp-bg-card);
  border: 1px solid var(--bsp-line);
  transition: border-color 0.25s ease;
}

.page-about__tech-item:hover {
  border-color: var(--bsp-info);
}

.page-about__tech-num {
  display: grid;
  place-items: center;
  width: 44px;
  height: 44px;
  border: 1px solid var(--bsp-line);
  font-family: var(--bsp-font-head);
  font-size: 18px;
  color: var(--bsp-green);
  background: var(--bsp-bg-deep);
}

.page-about__tech-item h3 {
  margin: 0 0 6px;
  font-family: var(--bsp-font-head);
  font-size: 18px;
  line-height: 1.2;
}

.page-about__tech-item p {
  margin: 0;
  color: var(--bsp-text-muted);
  font-size: 14px;
}

/* 质量 */
.page-about__quality-grid {
  display: grid;
  gap: 20px;
  margin-top: 36px;
}

.page-about__quality-card {
  padding: 30px 28px;
  background: var(--bsp-bg-card);
  border: 1px solid var(--bsp-line);
  position: relative;
  clip-path: polygon(0 0, calc(100% - 22px) 0, 100% 22px, 100% 100%, 0 100%);
  transition: border-color 0.25s ease;
}

.page-about__quality-card:hover {
  border-color: var(--bsp-green);
}

.page-about__quality-num {
  margin: 0 0 14px;
  font-family: var(--bsp-font-head);
  font-size: 44px;
  line-height: 1;
  color: var(--bsp-green);
}

.page-about__quality-card h3 {
  margin: 0 0 8px;
  font-family: var(--bsp-font-head);
  font-size: 18px;
  line-height: 1.2;
}

.page-about__quality-card p {
  margin: 0;
  color: var(--bsp-text-muted);
  font-size: 14px;
}

.page-about__quality-note {
  margin-top: 44px;
  padding: 24px 28px;
  border: 1px solid var(--bsp-line);
  background: rgba(57, 255, 20, 0.04);
}

.page-about__quality-note p {
  margin: 0 0 12px;
  color: var(--bsp-text-muted);
  font-size: 15px;
}

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

.page-about__quality-note a {
  color: var(--bsp-green);
  text-decoration: none;
  border-bottom: 1px solid rgba(57, 255, 20, 0.3);
}

.page-about__quality-note a:hover {
  border-bottom-color: var(--bsp-green);
}

/* 平板及以上 */
@media (min-width: 768px) {
  .page-about__hero {
    padding: 72px 0 96px;
  }

  .page-about__hero-inner {
    grid-template-columns: 1.15fr 0.85fr;
    gap: 56px;
  }

  .page-about__hero h1 {
    font-size: 54px;
  }

  .page-about__lede {
    font-size: 17px;
  }

  .page-about__toc-list {
    gap: 8px 28px;
  }

  .page-about__section {
    padding: 96px 0;
  }

  .page-about__section h2 {
    font-size: 42px;
  }

  .page-about__mission-grid {
    grid-template-columns: 1fr 1fr;
    gap: 64px;
    align-items: center;
  }

  .page-about__quality-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 24px;
  }
}

@media (min-width: 900px) {
  .page-about__tech-grid {
    grid-template-columns: 0.85fr 1.15fr;
    gap: 56px;
  }

  .page-about__timeline-item {
    --travel: 56px;
    grid-template-columns: 160px 48px 1fr;
    gap: 24px;
    padding-bottom: var(--travel);
  }

  .page-about__timeline-year {
    grid-column: auto;
    text-align: right;
    padding-top: 2px;
    font-size: 40px;
  }
}

@media (max-width: 360px) {
  .page-about__hero-stats dd {
    font-size: 22px;
  }
}