.page-about {
  --about-line-alpha: rgba(255, 255, 255, 0.16);
  --about-body-text: #3A4657;
}

/* 首屏：杂志封面 */
.page-about .about-cover {
  position: relative;
  background: var(--navy);
  color: var(--white);
  overflow: hidden;
}

.page-about .about-cover-bg {
  position: absolute;
  inset: 0;
  z-index: 0;
  overflow: hidden;
}

.page-about .about-cover-bg img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.36;
}

.page-about .about-cover::after {
  content: "";
  position: absolute;
  inset: 0;
  z-index: 1;
  background: linear-gradient(180deg, rgba(8, 18, 38, 0.55) 0%, rgba(11, 27, 58, 0.85) 68%, rgba(11, 27, 58, 0.96) 100%);
  pointer-events: none;
}

.page-about .about-cover-content {
  position: relative;
  z-index: 2;
  display: flex;
  flex-direction: column;
  justify-content: flex-end;
  min-height: 34rem;
  padding-top: 4.5rem;
  padding-bottom: 3.5rem;
}

.page-about .about-cover-crumb {
  margin-bottom: auto;
}

.page-about .about-cover-crumb .breadcrumb-link,
.page-about .about-cover-crumb .breadcrumb-current {
  color: var(--silver);
  font-size: 0.85rem;
}

.page-about .about-cover-crumb .breadcrumb-link:hover {
  color: var(--orange);
}

.page-about .about-cover-issue {
  order: 1;
  align-self: flex-end;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 700;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--orange);
  margin: 1.5rem 0 1.1rem;
}

.page-about .about-cover-title {
  order: 2;
  font-family: var(--font-heading);
  font-size: clamp(2.4rem, 8.5vw, 6rem);
  line-height: 0.98;
  letter-spacing: -0.03em;
  color: var(--white);
  margin: 0 0 1.4rem;
  text-wrap: balance;
}

.page-about .about-cover-quote {
  order: 3;
  font-size: clamp(1.05rem, 1.8vw, 1.35rem);
  line-height: 1.65;
  color: var(--white);
  border-left: 4px solid var(--orange);
  padding-left: 1.25rem;
  margin: 0 0 1.4rem;
  max-width: 32rem;
}

.page-about .about-cover-lead {
  order: 4;
  font-size: clamp(1rem, 2vw, 1.3rem);
  font-weight: 500;
  color: var(--silver);
  margin: 0 0 2rem;
  max-width: 30rem;
}

.page-about .about-cover-stats {
  order: 5;
  display: flex;
  flex-wrap: wrap;
  gap: 1.75rem 2.5rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--about-line-alpha);
}

.page-about .about-cover-stat {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
}

.page-about .about-cover-stat-num {
  font-family: var(--font-mono);
  font-size: clamp(1.75rem, 4vw, 2.6rem);
  font-weight: 700;
  line-height: 1;
  color: var(--orange);
}

.page-about .about-cover-stat-label {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  color: var(--silver);
}

/* 品牌宣言 */
.page-about .about-manifesto {
  background: var(--cream);
  padding: clamp(3.5rem, 8vw, 6.5rem) 0;
}

.page-about .about-manifesto-inner {
  max-width: 52rem;
  text-align: center;
}

.page-about .about-manifesto .about-section-index {
  justify-content: center;
}

.page-about .about-manifesto .about-section-kicker,
.page-about .about-manifesto .about-section-title {
  text-align: center;
}

.page-about .about-manifesto-quote {
  font-family: var(--font-heading);
  font-size: clamp(1.4rem, 3.5vw, 2.4rem);
  line-height: 1.45;
  color: var(--navy);
  border-left: 6px solid var(--orange);
  padding-left: 1.5rem;
  margin: 2.25rem auto 1.75rem;
  text-align: left;
  max-width: 40rem;
}

.page-about .about-manifesto-desc {
  font-size: 1rem;
  line-height: 1.85;
  color: var(--about-body-text);
  margin: 0 auto 1.75rem;
  text-align: left;
  max-width: 40rem;
}

.page-about .about-manifesto-desc strong {
  color: var(--navy);
  font-weight: 500;
}

.page-about .about-manifesto-link {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--orange);
  text-decoration: none;
}

.page-about .about-manifesto-link:hover {
  text-decoration: underline;
}

/* 章节通用头部 */
.page-about .about-section-head {
  max-width: 44rem;
  margin-bottom: clamp(2.5rem, 5vw, 4rem);
}

.page-about .about-section-index {
  display: inline-flex;
  align-items: center;
  gap: 0.75rem;
  font-family: var(--font-mono);
  font-size: 0.95rem;
  font-weight: 700;
  color: var(--orange);
}

.page-about .about-section-index::after {
  content: "";
  display: inline-block;
  width: 3rem;
  height: 3px;
  background: var(--orange);
}

.page-about .about-section-kicker {
  font-family: var(--font-mono);
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--rock);
  margin: 0.85rem 0 0.5rem;
}

.page-about .about-section-title {
  font-family: var(--font-heading);
  font-size: clamp(1.75rem, 4vw, 3rem);
  line-height: 1.12;
  letter-spacing: -0.01em;
  color: var(--navy);
  margin: 0 0 1rem;
}

.page-about .about-section-subtitle {
  font-size: 1rem;
  line-height: 1.75;
  color: var(--about-body-text);
  margin: 0;
}

/* 发展历程 */
.page-about .about-journey {
  background: var(--blue-gray);
  padding: clamp(3.5rem, 8vw, 6.5rem) 0;
}

.page-about .about-timeline-svg {
  display: none;
  width: 100%;
  height: auto;
  margin-bottom: 0.5rem;
}

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

.page-about .about-timeline-item {
  background: var(--white);
  border: 2px solid var(--navy);
  border-top: 6px solid var(--orange);
  box-shadow: var(--shadow-hard);
  padding: 1.75rem 1.5rem 1.5rem;
  transition: border-color 0.2s ease, transform 0.2s ease, box-shadow 0.2s ease;
}

.page-about .about-timeline-item:hover,
.page-about .about-timeline-item:focus-within {
  border-color: var(--orange);
  transform: translate(-2px, -2px);
  box-shadow: 6px 6px 0 rgba(11, 27, 58, 0.92);
}

.page-about .about-timeline-phase {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--orange);
  background: rgba(255, 107, 0, 0.1);
  padding: 0.3rem 0.65rem;
  margin-bottom: 0.85rem;
}

.page-about .about-timeline-heading {
  font-family: var(--font-heading);
  font-size: 1.3rem;
  line-height: 1.2;
  color: var(--navy);
  margin: 0 0 0.65rem;
}

.page-about .about-timeline-summary {
  font-size: 0.95rem;
  line-height: 1.7;
  color: var(--about-body-text);
  margin: 0;
}

.page-about .about-timeline-detail {
  display: none;
  margin-top: 1.1rem;
  padding-top: 1.1rem;
  border-top: 1px dashed var(--silver);
}

.page-about .about-timeline-detail-title {
  font-size: 0.82rem;
  font-weight: 700;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--rock);
  margin: 0 0 0.5rem;
}

.page-about .about-timeline-list {
  margin: 0 0 0.6rem;
  padding-left: 1.1rem;
  font-size: 0.9rem;
  line-height: 1.8;
  color: var(--about-body-text);
}

.page-about .about-timeline-detail p {
  font-size: 0.88rem;
  line-height: 1.7;
  color: var(--rock);
  margin: 0;
}

.page-about .about-journey-more {
  margin-top: 2.5rem;
  text-align: center;
}

.page-about .about-journey-more .text-link {
  font-family: var(--font-mono);
  font-size: 0.9rem;
  font-weight: 700;
  color: var(--navy);
  text-decoration: none;
  border-bottom: 2px solid var(--orange);
  padding-bottom: 0.2rem;
}

.page-about .about-journey-more .text-link:hover {
  color: var(--orange);
}

/* 技术里程碑 */
.page-about .about-milestone {
  background: var(--navy);
  color: var(--white);
  padding: clamp(3.5rem, 8vw, 6.5rem) 0;
}

.page-about .about-milestone .about-section-kicker {
  color: var(--silver);
}

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

.page-about .about-milestone .about-section-subtitle {
  color: var(--silver);
}

.page-about .about-milestone-grid {
  display: grid;
  gap: 1.25rem;
}

.page-about .about-milestone-card {
  background: rgba(255, 255, 255, 0.05);
  border: 2px solid var(--silver);
  color: var(--white);
  transition: border-color 0.2s ease, background 0.2s ease;
}

.page-about .about-milestone-card[open] {
  border-color: var(--orange);
  background: rgba(255, 107, 0, 0.07);
}

.page-about .about-milestone-summary {
  display: flex;
  align-items: center;
  gap: 1.25rem;
  padding: 1.6rem 1.5rem;
  cursor: pointer;
  list-style: none;
}

.page-about .about-milestone-summary::-webkit-details-marker {
  display: none;
}

.page-about .about-milestone-summary:focus-visible {
  outline: 2px solid var(--orange);
  outline-offset: 4px;
}

.page-about .about-milestone-icon {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: 0.82rem;
  font-weight: 700;
  color: var(--orange);
  border: 2px solid var(--orange);
  padding: 0.35rem 0.5rem;
  line-height: 1;
  letter-spacing: 0.08em;
}

.page-about .about-milestone-heading {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
}

.page-about .about-milestone-num {
  font-family: var(--font-mono);
  font-size: clamp(1.7rem, 4vw, 2.4rem);
  font-weight: 700;
  line-height: 1;
  color: var(--orange);
}

.page-about .about-milestone-unit {
  font-size: 0.55em;
  margin-left: 0.18em;
  color: var(--silver);
}

.page-about .about-milestone-label {
  font-size: 0.85rem;
  letter-spacing: 0.08em;
  color: var(--silver);
}

.page-about .about-milestone-desc {
  padding: 0 1.5rem 1.6rem;
  margin: 0;
  font-size: 0.95rem;
  line-height: 1.75;
  color: var(--silver);
}

.page-about .about-milestone-card[open] .about-milestone-desc {
  animation: story-milestone-fade 0.25s ease-out;
}

@keyframes story-milestone-fade {
  from {
    opacity: 0;
    transform: translateY(-4px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.page-about .about-milestone-figure {
  margin: 3rem auto 0;
  max-width: 18rem;
}

.page-about .about-milestone-figure img {
  display: block;
  width: 100%;
  height: auto;
  border: 2px solid var(--orange);
  box-shadow: 6px 6px 0 rgba(255, 107, 0, 0.55);
}

.page-about .about-milestone-figure figcaption {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--silver);
  text-align: center;
  margin-top: 0.9rem;
}

/* 服务理念 */
.page-about .about-service {
  background: var(--white);
  padding: clamp(3.5rem, 8vw, 6.5rem) 0;
}

.page-about .about-service-grid {
  display: grid;
  gap: 2.75rem;
}

.page-about .about-service-block {
  margin-bottom: 2rem;
  padding-left: 1.5rem;
  border-left: 4px solid var(--orange);
}

.page-about .about-service-title {
  font-family: var(--font-heading);
  font-size: 1.3rem;
  line-height: 1.3;
  color: var(--navy);
  margin: 0 0 0.85rem;
}

.page-about .about-service-text {
  font-size: 1rem;
  line-height: 1.85;
  color: var(--about-body-text);
  margin: 0;
}

.page-about .about-service-btn {
  margin-top: 0.5rem;
}

.page-about .about-service-figure {
  margin: 0;
}

.page-about .about-service-figure img {
  display: block;
  width: 100%;
  height: auto;
  border: 2px solid var(--navy);
  box-shadow: var(--shadow-hard);
}

.page-about .about-service-figure figcaption {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--rock);
  margin-top: 0.9rem;
}

/* 桌面端适配 */
@media (min-width: 960px) {
  .page-about .about-cover-content {
    display: grid;
    grid-template-columns: minmax(0, 1.5fr) minmax(0, 1fr);
    grid-template-areas:
      "crumb issue"
      "title title"
      "quote lead"
      "stats stats";
    column-gap: clamp(2.5rem, 6vw, 5rem);
    row-gap: 1.4rem;
    align-content: end;
    min-height: 90vh;
    padding-top: 5.5rem;
    padding-bottom: 4rem;
  }

  .page-about .about-cover-crumb {
    grid-area: crumb;
    margin-bottom: 0;
  }

  .page-about .about-cover-issue {
    grid-area: issue;
    align-self: start;
    margin: 0.2rem 0 0;
  }

  .page-about .about-cover-title {
    grid-area: title;
    margin: 0;
    font-size: clamp(3.6rem, 7.2vw, 6rem);
  }

  .page-about .about-cover-quote {
    grid-area: quote;
    align-self: end;
    margin: 0;
    max-width: 26rem;
  }

  .page-about .about-cover-lead {
    grid-area: lead;
    align-self: start;
    margin: 0;
    max-width: 26rem;
  }

  .page-about .about-cover-stats {
    grid-area: stats;
    margin-top: 1.5rem;
  }

  .page-about .about-timeline-svg {
    display: block;
  }

  .page-about .about-timeline-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1.75rem;
  }

  .page-about .about-timeline-item {
    padding: 2rem 1.75rem 1.75rem;
  }

  .page-about .about-timeline-detail {
    display: none;
  }

  .page-about .about-timeline-item:hover .about-timeline-detail,
  .page-about .about-timeline-item:focus-within .about-timeline-detail {
    display: block;
  }

  .page-about .about-milestone-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1.5rem;
  }

  .page-about .about-milestone-summary {
    flex-direction: column;
    align-items: flex-start;
    gap: 1rem;
    padding: 2rem 1.75rem 1.5rem;
  }

  .page-about .about-milestone-heading {
    flex-direction: row;
    align-items: baseline;
    gap: 0.8rem;
    flex-wrap: wrap;
  }

  .page-about .about-milestone-num {
    font-size: clamp(2rem, 3.4vw, 2.8rem);
  }

  .page-about .about-milestone-label {
    font-size: 0.9rem;
  }

  .page-about .about-milestone-desc {
    padding: 0 1.75rem 2rem;
  }

  .page-about .about-service-grid {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr);
    gap: 4rem;
    align-items: center;
  }
}

/* 无 hover 触屏设备：时间线细节始终可见 */
@media (hover: none) {
  .page-about .about-timeline-detail {
    display: block;
  }
}