.page-about {
  --about-hero-gradient: linear-gradient(135deg, var(--green), var(--deep-blue));
  --about-card-shadow: 0 4px 20px rgba(0, 0, 0, 0.08);
  --about-radius-lg: 32px;
  --about-radius-card: 20px;
  display: block;
  width: 100%;
  max-width: 100%;
  overflow-x: hidden;
  font-family: "Noto Sans SC", "PingFang SC", system-ui, sans-serif;
  font-size: 16px;
  line-height: 1.6;
  color: var(--deep-gray);
  background: var(--light-gray);
}

/* 面包屑 */
.page-about .breadcrumb {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 1rem 1.25rem 0;
  font-size: 0.85rem;
}
.page-about .breadcrumb ol {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  list-style: none;
  margin: 0;
  padding: 0;
}
.page-about .breadcrumb li {
  display: flex;
  align-items: center;
  gap: 0.4rem;
}
.page-about .breadcrumb li + li::before {
  content: "/";
  color: var(--deep-gray);
  opacity: 0.4;
}
.page-about .breadcrumb a {
  color: var(--deep-blue);
  text-decoration: none;
  font-weight: 500;
}
.page-about .breadcrumb a:hover {
  text-decoration: underline;
}
.page-about .breadcrumb [aria-current="page"] {
  color: var(--deep-gray);
  font-weight: 600;
}

/* 首屏框景 */
.page-about .hero-framed {
  max-width: var(--container-max);
  margin: 1.25rem auto;
  margin-bottom: 2.5rem;
  border: 4px solid var(--deep-blue);
  border-radius: var(--about-radius-lg);
  background: var(--about-hero-gradient);
  color: var(--white);
  position: relative;
  overflow: hidden;
}
.page-about .hero-framed::before {
  content: "";
  position: absolute;
  top: 10px;
  left: 10px;
  right: 10px;
  bottom: 10px;
  border: 2px dashed rgba(255, 255, 255, 0.25);
  border-radius: calc(var(--about-radius-lg) - 6px);
  pointer-events: none;
  z-index: 0;
}
.page-about .hero-framed::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 6px;
  background: repeating-linear-gradient(90deg, var(--orange), var(--orange) 24px, transparent 24px, transparent 48px);
  z-index: 1;
  pointer-events: none;
}
.page-about .hero-framed__inner {
  position: relative;
  z-index: 2;
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  padding: 2rem 1.5rem 1.8rem;
}
.page-about .hero-framed__label {
  display: inline-block;
  background: var(--orange);
  color: var(--white);
  font-size: 0.75rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  padding: 0.3rem 1rem;
  border-radius: 100px;
  margin-bottom: 0.25rem;
  align-self: flex-start;
}
.page-about .hero-framed__text h1 {
  font-family: "Arial Black", "Impact", sans-serif;
  font-style: italic;
  font-weight: 900;
  font-size: 2.2rem;
  line-height: 1.15;
  margin: 0 0 0.75rem;
  color: var(--white);
  text-shadow: 0 2px 12px rgba(0, 0, 0, 0.25);
}
.page-about .hero-framed__lead {
  font-size: 1rem;
  line-height: 1.7;
  margin: 0 0 1.25rem;
  opacity: 0.92;
  max-width: 580px;
}
.page-about .hero-framed__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}
.page-about .hero-framed__actions .btn {
  font-weight: 700;
  border: none;
  padding: 0.7rem 1.6rem;
  border-radius: 60px;
  font-size: 0.95rem;
  cursor: pointer;
  text-decoration: none;
  display: inline-block;
  transition: transform 0.2s, box-shadow 0.2s;
}
.page-about .hero-framed__actions .btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(0, 0, 0, 0.2);
}
.page-about .hero-framed__actions .btn-accent {
  background: var(--orange);
  color: var(--white);
}
.page-about .hero-framed__actions .btn-primary {
  background: var(--white);
  color: var(--deep-blue);
}
.page-about .hero-framed__visual {
  display: flex;
  align-items: center;
  justify-content: center;
}
.page-about .hero-framed__visual img {
  width: 100%;
  max-width: 100%;
  height: auto;
  border-radius: 16px;
  object-fit: cover;
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.3);
  display: block;
}

/* 通用节标题 */
.page-about .section-label {
  font-family: "Arial Black", "Impact", sans-serif;
  font-style: italic;
  font-weight: 900;
  font-size: 1.6rem;
  margin: 0 0 1.25rem;
  color: var(--deep-blue);
  position: relative;
  display: inline-block;
}
.page-about .section-label::after {
  content: "";
  display: block;
  width: 48px;
  height: 4px;
  background: var(--orange);
  border-radius: 4px;
  margin-top: 0.35rem;
}

/* 核心功能 — 时间轴 */
.page-about .core-features {
  padding: 2.5rem 0 1.5rem;
  background: var(--light-gray);
}
.page-about .core-features .container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 1.25rem;
}
.page-about .timeline {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}
.page-about .timeline__item {
  background: var(--white);
  border-radius: var(--about-radius-card);
  box-shadow: var(--about-card-shadow);
  overflow: hidden;
  border-left: 4px solid var(--green);
  transition: border-color 0.25s;
}
.page-about .timeline__item[data-open="true"] {
  border-left-color: var(--orange);
}
.page-about .timeline__trigger {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  background: none;
  border: none;
  padding: 1.1rem 1.25rem;
  font-family: inherit;
  font-size: 1.05rem;
  font-weight: 700;
  color: var(--deep-blue);
  cursor: pointer;
  text-align: left;
  transition: background 0.2s;
  gap: 0.75rem;
}
.page-about .timeline__trigger:hover {
  background: rgba(76, 175, 80, 0.06);
}
.page-about .timeline__year {
  flex: 1;
}
.page-about .timeline__icon {
  font-size: 1.4rem;
  font-weight: 300;
  color: var(--green);
  transition: transform 0.3s;
  flex-shrink: 0;
  line-height: 1;
}
.page-about .timeline__item[data-open="true"] .timeline__icon {
  transform: rotate(45deg);
  color: var(--orange);
}
.page-about .timeline__content {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, padding 0.3s ease;
  padding: 0 1.25rem;
}
.page-about .timeline__content[data-open="true"] {
  max-height: 600px;
  padding: 0 1.25rem 1.25rem;
}
.page-about .timeline__content p {
  margin: 0 0 0.75rem;
  font-size: 0.95rem;
  line-height: 1.7;
  color: var(--deep-gray);
}
.page-about .timeline__content img {
  width: 100%;
  max-width: 280px;
  height: auto;
  border-radius: 12px;
  object-fit: cover;
  display: block;
  margin-top: 0.5rem;
}

/* 数据保障 */
.page-about .data-assurance {
  padding: 2.5rem 0 2rem;
  background: var(--white);
}
.page-about .data-assurance .container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 1.25rem;
}
.page-about .assurance-grid {
  display: grid;
  gap: 1.25rem;
  margin-bottom: 1.75rem;
}
.page-about .assurance-card {
  background: var(--light-gray);
  border-radius: var(--about-radius-card);
  padding: 1.5rem;
  box-shadow: var(--about-card-shadow);
  border: 1px solid rgba(76, 175, 80, 0.15);
  transition: transform 0.2s, box-shadow 0.2s;
}
.page-about .assurance-card:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.12);
}
.page-about .assurance-card__icon {
  font-size: 2.2rem;
  display: inline-block;
  margin-bottom: 0.5rem;
  line-height: 1;
}
.page-about .assurance-card h3 {
  font-family: "Arial Black", "Impact", sans-serif;
  font-style: italic;
  font-weight: 900;
  font-size: 1.2rem;
  margin: 0 0 0.5rem;
  color: var(--deep-blue);
}
.page-about .assurance-card p {
  margin: 0;
  font-size: 0.92rem;
  line-height: 1.65;
  color: var(--deep-gray);
}

/* 历史版本预览交互 */
.page-about .history-preview {
  background: var(--light-gray);
  border-radius: var(--about-radius-card);
  overflow: hidden;
  box-shadow: var(--about-card-shadow);
  margin-bottom: 1.5rem;
}
.page-about .history-preview__trigger {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  background: none;
  border: none;
  padding: 1rem 1.25rem;
  font-family: inherit;
  font-size: 1rem;
  font-weight: 700;
  color: var(--deep-blue);
  cursor: pointer;
  text-align: left;
  transition: background 0.2s;
}
.page-about .history-preview__trigger:hover {
  background: rgba(26, 35, 126, 0.06);
}
.page-about .history-preview__arrow {
  font-size: 1.2rem;
  transition: transform 0.3s;
  color: var(--orange);
}
.page-about .history-preview[data-open="true"] .history-preview__arrow {
  transform: rotate(90deg);
}
.page-about .history-preview__content {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.4s ease, padding 0.3s ease;
  padding: 0 1.25rem;
}
.page-about .history-preview__content[data-open="true"] {
  max-height: 300px;
  padding: 0 1.25rem 1.25rem;
}
.page-about .history-preview__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}
.page-about .history-preview__list li {
  padding: 0.6rem 0.8rem;
  background: var(--white);
  border-radius: 8px;
  font-size: 0.9rem;
  color: var(--deep-gray);
  border-left: 3px solid var(--green);
}
.page-about .history-preview__list strong {
  color: var(--deep-blue);
}

/* 信任声明 */
.page-about .trust-statement {
  text-align: center;
  font-size: 0.95rem;
  font-weight: 600;
  color: var(--deep-blue);
  background: rgba(76, 175, 80, 0.08);
  padding: 0.8rem 1.25rem;
  border-radius: 60px;
  display: inline-block;
  width: auto;
  margin: 0 auto;
}

/* 内部链接导航 */
.page-about .page-links {
  padding: 2rem 0 2.5rem;
  background: var(--light-gray);
}
.page-about .page-links .container {
  max-width: var(--container-max);
  margin: 0 auto;
  padding: 0 1.25rem;
}
.page-about .page-links__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}
.page-about .page-links__list li {
  margin: 0;
}
.page-about .page-links__list a {
  display: inline-block;
  padding: 0.5rem 1.25rem;
  background: var(--white);
  color: var(--deep-blue);
  text-decoration: none;
  font-weight: 600;
  font-size: 0.9rem;
  border-radius: 60px;
  border: 1.5px solid rgba(26, 35, 126, 0.2);
  transition: background 0.2s, border-color 0.2s, transform 0.15s;
}
.page-about .page-links__list a:hover {
  background: var(--deep-blue);
  color: var(--white);
  border-color: var(--deep-blue);
  transform: translateY(-2px);
}

/* 桌面端 ≥768px */
@media (min-width: 768px) {
  .page-about .breadcrumb {
    padding: 1.25rem 2rem 0;
  }
  .page-about .hero-framed__inner {
    flex-direction: row;
    align-items: center;
    padding: 2.5rem 2.5rem 2.2rem;
    gap: 2.5rem;
  }
  .page-about .hero-framed__text {
    flex: 1 1 55%;
  }
  .page-about .hero-framed__text h1 {
    font-size: 3rem;
  }
  .page-about .hero-framed__lead {
    font-size: 1.1rem;
  }
  .page-about .hero-framed__visual {
    flex: 0 0 42%;
  }
  .page-about .hero-framed__visual img {
    max-width: 100%;
    border-radius: 20px;
  }

  .page-about .section-label {
    font-size: 2rem;
  }

  .page-about .core-features {
    padding: 3.5rem 0 2rem;
  }
  .page-about .core-features .container {
    padding: 0 2rem;
  }
  .page-about .timeline {
    gap: 0.75rem;
  }
  .page-about .timeline__trigger {
    padding: 1.2rem 1.5rem;
    font-size: 1.1rem;
  }
  .page-about .timeline__content[data-open="true"] {
    padding: 0 1.5rem 1.5rem;
  }

  .page-about .data-assurance {
    padding: 3.5rem 0 2.5rem;
  }
  .page-about .data-assurance .container {
    padding: 0 2rem;
  }
  .page-about .assurance-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 1.5rem;
  }
  .page-about .assurance-card {
    padding: 1.75rem;
  }

  .page-about .history-preview {
    max-width: 520px;
  }

  .page-about .page-links {
    padding: 2.5rem 0 3rem;
  }
  .page-about .page-links .container {
    padding: 0 2rem;
  }
  .page-about .page-links__list {
    gap: 1rem;
  }
  .page-about .page-links__list a {
    padding: 0.6rem 1.6rem;
    font-size: 0.95rem;
  }
}

/* 大桌面端 ≥1024px */
@media (min-width: 1024px) {
  .page-about .hero-framed__text h1 {
    font-size: 3.8rem;
  }
  .page-about .hero-framed__lead {
    font-size: 1.2rem;
    max-width: 640px;
  }
  .page-about .hero-framed__inner {
    padding: 3rem 3rem 2.5rem;
    gap: 3rem;
  }
  .page-about .section-label {
    font-size: 2.2rem;
  }
}