.page-about {
  --about-hero-gutter: 2rem;
}

/* ===== Hero ===== */
.page-about .about-hero {
  background: var(--color-primary);
  color: var(--color-white);
  padding-top: 132px;
  padding-bottom: 64px;
  position: relative;
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: 0;
  right: -8%;
  width: 48%;
  height: 100%;
  background: repeating-linear-gradient(-35deg, transparent 0 18px, rgba(255, 255, 255, 0.045) 18px 20px);
  pointer-events: none;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 36%;
  height: 4px;
  background: var(--color-accent);
  transform: skewX(-22deg);
  transform-origin: left bottom;
}

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

.page-about .about-hero .breadcrumb {
  margin-bottom: 28px;
  color: rgba(255, 255, 255, 0.6);
}

.page-about .about-hero .breadcrumb a {
  color: rgba(255, 255, 255, 0.9);
  text-decoration: none;
}

.page-about .about-hero .breadcrumb a:hover {
  color: var(--color-accent);
}

.page-about .about-hero-meta {
  display: flex;
  flex-wrap: wrap;
  gap: 10px 18px;
  align-items: center;
  margin-bottom: 22px;
}

.page-about .about-hero .page-hero-index {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--color-accent);
  border: 1px solid rgba(255, 255, 255, 0.3);
  padding: 5px 12px;
  border-radius: 999px;
  display: inline-flex;
  align-items: center;
}

.page-about .about-hero-year {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  letter-spacing: 0.08em;
  color: rgba(255, 255, 255, 0.7);
}

.page-about .about-hero-title {
  max-width: 16em;
  margin-bottom: 20px;
  color: var(--color-white);
  font-size: clamp(1.75rem, 3vw + 1rem, 3rem);
  line-height: 1.18;
  letter-spacing: -0.01em;
}

.page-about .about-hero-sub {
  max-width: 42em;
  margin: 0;
  color: rgba(255, 255, 255, 0.82);
  font-size: clamp(0.95rem, 0.6vw + 0.75rem, 1.1rem);
  line-height: 1.68;
}

/* ===== 通用区块标题 ===== */
.page-about .section-head {
  position: relative;
  padding-bottom: 22px;
  margin-bottom: 12px;
}

.page-about .section-head::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 84px;
  height: 4px;
  background: var(--color-accent);
  clip-path: polygon(0 0, 68px 0, 100% 100%, 20px 100%);
}

.page-about .section-index {
  font-family: var(--font-mono);
  font-size: 0.85rem;
  letter-spacing: 0.14em;
  color: var(--color-accent);
  text-transform: uppercase;
}

/* ===== 品牌使命 ===== */
.page-about .about-mission,
.page-about .about-scale {
  padding-top: 72px;
  padding-bottom: 72px;
}

.page-about .mission-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 30px;
  margin-top: 36px;
}

.page-about .mission-principle {
  background: var(--color-light-gray);
  border: 1px solid var(--color-mid-gray);
  border-top: 4px solid var(--color-accent);
  padding: 30px 26px;
  position: relative;
}

.page-about .mission-principle .board-index {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-accent);
  margin-bottom: 12px;
  display: inline-block;
}

.page-about .mission-principle h3 {
  margin: 0 0 12px;
  font-size: 1.4rem;
  color: var(--color-primary);
  line-height: 1.3;
}

.page-about .mission-principle p {
  margin: 0 0 14px;
  line-height: 1.7;
  color: var(--color-dark-gray);
}

.page-about .mission-track {
  list-style: none;
  margin: 0;
  padding: 0;
  border-left: 2px solid var(--color-mid-gray);
}

.page-about .mission-track li {
  position: relative;
  padding: 0 0 28px 26px;
}

.page-about .mission-track li:last-child {
  padding-bottom: 0;
}

.page-about .mission-track li::before {
  content: "";
  position: absolute;
  left: -8px;
  top: 4px;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--color-accent);
  border: 3px solid var(--color-white);
  box-shadow: 0 0 0 2px var(--color-accent);
}

.page-about .mission-num {
  font-family: var(--font-mono);
  font-size: 0.8rem;
  letter-spacing: 0.1em;
  color: var(--color-accent);
}

.page-about .mission-track h3 {
  margin: 8px 0 6px;
  font-size: 1.08rem;
  color: var(--color-primary);
}

.page-about .mission-track p {
  margin: 0;
  line-height: 1.65;
  color: var(--color-dark-gray);
  font-size: 0.93rem;
}

/* ===== 发展里程碑 ===== */
.page-about .about-timeline,
.page-about .about-team {
  padding-top: 72px;
  padding-bottom: 72px;
  background: var(--color-light-gray);
}

.page-about .timeline-figure {
  margin: 36px 0 44px;
  background: var(--color-white);
  border: 1px solid var(--color-mid-gray);
  padding: 10px;
}

.page-about .timeline-figure img,
.page-about .version-figure img,
.page-about .team-figure img {
  display: block;
  max-width: 100%;
  width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .timeline-figure figcaption {
  padding: 12px 4px 2px;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--color-dark-gray);
  letter-spacing: 0.04em;
}

.page-about .timeline-list {
  margin-top: 8px;
}

.page-about .tl-item {
  position: relative;
  border-left: 3px solid var(--color-primary);
  padding: 0 0 34px 24px;
}

.page-about .tl-item::before {
  content: "";
  position: absolute;
  left: -11px;
  top: 6px;
  width: 19px;
  height: 19px;
  border-radius: 50%;
  background: var(--color-accent);
  border: 4px solid var(--color-white);
  box-shadow: 0 0 0 2px var(--color-accent);
}

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

.page-about .tl-toggle {
  width: 100%;
  display: flex;
  align-items: flex-start;
  gap: 14px;
  padding: 0;
  margin: 0;
  border: 0;
  background: transparent;
  cursor: pointer;
  font-family: var(--font-body);
  text-align: left;
  color: var(--color-primary);
}

.page-about .tl-year {
  flex-shrink: 0;
  font-family: var(--font-mono);
  font-size: clamp(1.4rem, 2vw + 0.7rem, 2rem);
  line-height: 1.1;
  font-weight: 700;
  color: var(--color-accent);
  min-width: 3.8em;
  letter-spacing: -0.02em;
}

.page-about .tl-heading {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding-top: 2px;
}

.page-about .tl-heading strong {
  font-size: 1.12rem;
  font-weight: 700;
  line-height: 1.3;
}

.page-about .tl-tag {
  align-self: flex-start;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--color-dark-gray);
  background: var(--color-light-gray);
  border-radius: 999px;
  padding: 3px 10px;
}

.page-about .tl-toggle .faq-icon {
  position: relative;
  flex-shrink: 0;
  width: 22px;
  height: 22px;
  margin-top: 4px;
  color: var(--color-accent);
}

.page-about .tl-toggle .faq-icon::before,
.page-about .tl-toggle .faq-icon::after {
  content: "";
  position: absolute;
  background: currentColor;
  border-radius: 2px;
}

.page-about .tl-toggle .faq-icon::before {
  top: 10px;
  left: 2px;
  width: 18px;
  height: 2px;
}

.page-about .tl-toggle .faq-icon::after {
  top: 2px;
  left: 10px;
  width: 2px;
  height: 18px;
}

.page-about .tl-toggle[aria-expanded="true"] .faq-icon::after {
  display: none;
}

.page-about .tl-item .faq-answer-inner {
  padding: 16px 0 4px;
  line-height: 1.7;
  color: var(--color-dark-gray);
}

.page-about .tl-item .faq-answer-inner p {
  margin: 0;
  max-width: 46em;
}

/* ===== 服务规模 ===== */
.page-about .scale-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
  margin: 34px 0 0;
}

.page-about .scale-item {
  background: var(--color-white);
  border: 1px solid var(--color-mid-gray);
  padding: 26px 16px 22px;
  text-align: center;
  transition: transform var(--transition-fast), border-color var(--transition-fast), box-shadow var(--transition-fast);
}

.page-about .scale-item:hover {
  transform: scale(1.04);
  border-color: var(--color-accent);
  box-shadow: 0 10px 24px rgba(10, 37, 64, 0.08);
}

.page-about .scale-item dt {
  margin: 0 0 12px;
  font-size: 0.83rem;
  color: var(--color-dark-gray);
  letter-spacing: 0.06em;
}

.page-about .scale-item dd {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(1.4rem, 2vw + 0.8rem, 2.3rem);
  line-height: 1.1;
  font-weight: 700;
  color: var(--color-primary);
}

.page-about .scale-note {
  margin: 26px 0 0;
  color: var(--color-dark-gray);
  font-size: 0.92rem;
  line-height: 1.7;
  max-width: 48em;
}

/* ===== 版本兼容策略 ===== */
.page-about .about-versions {
  background: var(--color-primary);
  color: var(--color-white);
  padding-top: 72px;
  padding-bottom: 72px;
  position: relative;
  overflow: hidden;
}

.page-about .about-versions::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 42%;
  height: 4px;
  background: var(--color-accent);
  transform: skewX(-20deg);
  transform-origin: left top;
}

.page-about .about-versions .section-title {
  color: var(--color-white);
}

.page-about .about-versions .section-desc {
  color: rgba(255, 255, 255, 0.72);
}

.page-about .version-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 30px;
  margin-top: 36px;
}

.page-about .version-board {
  background: var(--color-white);
  border-top: 4px solid var(--color-accent);
  padding: 28px 26px;
  position: relative;
}

.page-about .version-board::after {
  content: "";
  position: absolute;
  right: 0;
  bottom: 0;
  width: 16%;
  height: 4px;
  background: var(--color-accent);
  transform: skewX(-20deg);
  transform-origin: left bottom;
}

.page-about .version-board .board-index {
  display: inline-block;
  margin-bottom: 14px;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--color-accent);
}

.page-about .version-board h3 {
  margin: 0 0 12px;
  font-size: 1.25rem;
  color: var(--color-primary);
  line-height: 1.3;
}

.page-about .version-board p {
  margin: 0;
  line-height: 1.7;
  color: var(--color-dark-gray);
}

.page-about .version-checks {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
}

.page-about .version-checks li {
  position: relative;
  padding: 11px 0 11px 26px;
  line-height: 1.6;
  border-bottom: 1px solid rgba(255, 255, 255, 0.14);
  color: rgba(255, 255, 255, 0.88);
  font-size: 0.93rem;
}

.page-about .version-checks li::before {
  content: "→";
  position: absolute;
  left: 0;
  top: 11px;
  color: var(--color-accent);
  font-weight: 700;
}

.page-about .version-notice {
  margin-top: 24px;
  background: rgba(232, 240, 254, 0.12);
  border: 1px solid rgba(232, 240, 254, 0.22);
  padding: 17px 20px;
  font-size: 0.92rem;
  line-height: 1.65;
  color: rgba(255, 255, 255, 0.9);
}

.page-about .version-notice strong {
  color: var(--color-accent);
}

.page-about .version-figure {
  margin: 0;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.18);
  padding: 10px;
}

.page-about .version-figure figcaption {
  padding: 12px 4px 2px;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: rgba(255, 255, 255, 0.7);
  letter-spacing: 0.04em;
}

/* ===== 团队与资质 ===== */
.page-about .team-layout {
  display: grid;
  grid-template-columns: 1fr;
  gap: 30px;
  margin-top: 36px;
  align-items: start;
}

.page-about .team-figure {
  margin: 0;
  background: var(--color-white);
  border: 1px solid var(--color-mid-gray);
  padding: 10px;
}

.page-about .team-figure figcaption {
  padding: 12px 4px 2px;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--color-dark-gray);
  letter-spacing: 0.04em;
}

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

.page-about .team-list li {
  display: flex;
  gap: 16px;
  padding: 18px 0;
  border-bottom: 1px solid var(--color-mid-gray);
}

.page-about .team-num {
  flex-shrink: 0;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  color: var(--color-accent);
  margin-top: 5px;
  letter-spacing: 0.08em;
}

.page-about .team-list h3 {
  margin: 0 0 6px;
  font-size: 1.03rem;
  color: var(--color-primary);
}

.page-about .team-list p {
  margin: 0;
  font-size: 0.92rem;
  line-height: 1.65;
  color: var(--color-dark-gray);
}

.page-about .team-cta {
  margin-top: 26px;
  background: var(--color-white);
  border: 1px solid var(--color-dark-gray);
  border-top: 4px solid var(--color-accent);
  padding: 24px;
}

.page-about .team-cta p {
  margin: 0 0 18px;
  line-height: 1.65;
  color: var(--color-dark-gray);
}

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

/* ===== 桌面端断点 ===== */
@media (min-width: 768px) {
  .page-about .mission-layout {
    grid-template-columns: 1.1fr 0.9fr;
    gap: 42px;
    align-items: start;
  }

  .page-about .scale-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 18px;
  }

  .page-about .timeline-list {
    max-width: 76%;
  }

  .page-about .tl-item {
    padding-left: 32px;
  }
}

@media (min-width: 980px) {
  .page-about .about-hero {
    padding-top: 160px;
    padding-bottom: 88px;
  }

  .page-about .version-layout {
    grid-template-columns: 1.05fr 0.95fr;
    gap: 44px;
    align-items: center;
  }

  .page-about .team-layout {
    grid-template-columns: 0.9fr 1.1fr;
    gap: 44px;
  }
}