.page-about {
  background: var(--c-warm);
  color: var(--c-ink);
  overflow-x: hidden;
}

.page-about .breadcrumb {
  margin: 1rem 0 1.5rem;
  font-size: 0.875rem;
  font-family: var(--font-sans);
  color: var(--c-gray);
}

.page-about .breadcrumb a {
  color: var(--c-azure);
  text-decoration: none;
}

.page-about .breadcrumb a:hover {
  color: var(--c-orange);
}

.page-about .breadcrumb__sep {
  margin: 0 0.375rem;
  opacity: 0.6;
}

/* ========== 首屏 ========== */
.page-about .about-hero {
  position: relative;
  margin-bottom: 5rem;
  padding: 2rem 1.5rem;
  border-radius: var(--r-lg);
  background: linear-gradient(140deg, var(--c-deep) 0%, var(--c-bay) 55%, var(--c-azure) 140%);
  color: #fff;
  overflow: hidden;
  isolation: isolate;
}

.page-about .about-hero__watermark {
  position: absolute;
  right: -0.5rem;
  top: 1rem;
  z-index: -1;
  font-family: var(--font-mono);
  font-size: clamp(3.5rem, 10vw, 7rem);
  font-weight: 800;
  letter-spacing: -0.05em;
  color: rgba(255, 255, 255, 0.06);
  pointer-events: none;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  width: 320px;
  height: 320px;
  right: -120px;
  top: 50%;
  transform: translateY(-50%);
  border: 2px solid rgba(255, 255, 255, 0.12);
  border-radius: 50%;
  z-index: -1;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  width: 220px;
  height: 220px;
  right: -60px;
  top: 50%;
  transform: translateY(-50%);
  border: 1px dashed rgba(255, 255, 255, 0.16);
  border-radius: 50%;
  z-index: -1;
}

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

.page-about .about-hero__eyebrow {
  margin: 0 0 1rem;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 600;
  letter-spacing: 0.06em;
  color: var(--c-amber);
}

.page-about .about-hero h1 {
  margin: 0 0 1.25rem;
  font-family: var(--font-sans);
  font-size: clamp(2.4rem, 6vw, 4rem);
  font-weight: 800;
  line-height: 1.12;
  letter-spacing: -0.02em;
}

.page-about .about-hero__lead {
  max-width: 34em;
  margin: 0 0 1.75rem;
  font-family: var(--font-serif);
  font-size: 1.0625rem;
  line-height: 1.8;
  color: rgba(255, 255, 255, 0.86);
}

.page-about .about-hero__stats {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem 1.75rem;
  margin: 0 0 2rem;
  padding: 0;
  list-style: none;
}

.page-about .about-hero__stats li {
  display: flex;
  flex-direction: column;
  font-size: 0.75rem;
  color: rgba(255, 255, 255, 0.64);
}

.page-about .about-hero__stats strong {
  font-family: var(--font-mono);
  font-size: 1.25rem;
  font-weight: 700;
  color: #fff;
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.page-about .about-hero__actions .btn {
  min-width: 8.5rem;
  justify-content: center;
}

.page-about .about-hero__visual {
  margin-top: 2rem;
  border-radius: var(--r-md);
  overflow: hidden;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
}

.page-about .about-hero__visual img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .section-head {
  margin-bottom: 2rem;
}

.page-about .section-head__index {
  display: inline-block;
  margin-bottom: 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 800;
  letter-spacing: 0.08em;
  color: var(--c-orange);
}

.page-about .section-head__title {
  margin: 0;
  font-family: var(--font-sans);
  font-size: clamp(1.75rem, 3vw, 2.4rem);
  font-weight: 800;
  line-height: 1.2;
  color: var(--c-ink);
}

.page-about .section-head__lead {
  max-width: 42em;
  margin: 0.75rem 0 0;
  font-size: 1rem;
  line-height: 1.75;
  color: var(--c-gray);
}

/* ========== 我们是谁 ========== */
.page-about .about-identity {
  margin-bottom: 5rem;
}

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

.page-about .about-identity__card {
  padding: 1.75rem;
}

.page-about .about-identity__card h3 {
  margin: 0 0 0.75rem;
  font-family: var(--font-sans);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--c-bay);
}

.page-about .about-identity__card p {
  margin: 0 0 0.75rem;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--c-gray);
}

.page-about .about-identity__card p:last-child {
  margin-bottom: 0;
}

.page-about .about-identity__facts {
  margin: 0 0 1rem;
  padding: 0;
  list-style: none;
}

.page-about .about-identity__facts li {
  display: grid;
  grid-template-columns: 5.5em 1fr;
  gap: 0.75rem;
  padding: 0.625rem 0;
  border-bottom: 1px solid rgba(11, 31, 58, 0.08);
  font-size: 0.875rem;
}

.page-about .about-identity__facts li span {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--c-gray);
  padding-top: 0.125rem;
}

.page-about .about-identity__facts li strong {
  font-weight: 600;
  line-height: 1.6;
  color: var(--c-ink);
  word-break: break-all;
}

.page-about .about-identity__note {
  font-size: 0.8125rem;
  color: var(--c-gray);
}

/* ========== 新旧版对比 ========== */
.page-about .about-evolution {
  margin-bottom: 5rem;
  padding: 2.5rem 1.25rem;
  border-radius: var(--r-lg);
  background: linear-gradient(180deg, rgba(214, 234, 248, 0.7) 0%, rgba(214, 234, 248, 0.25) 100%);
}

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

.page-about .about-evolution__col {
  border-radius: var(--r-md);
  padding: 1.5rem;
  background: #fff;
  box-shadow: var(--shadow-soft);
}

.page-about .about-evolution__col--old {
  opacity: 0.86;
  border: 1px dashed rgba(11, 31, 58, 0.2);
}

.page-about .about-evolution__col--new {
  border: 2px solid var(--c-orange);
  box-shadow: var(--shadow-hover);
}

.page-about .about-evolution__col-head {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  margin-bottom: 0.875rem;
}

.page-about .about-evolution__col-head h3 {
  margin: 0;
  font-family: var(--font-sans);
  font-size: 1.375rem;
  font-weight: 800;
  color: var(--c-deep);
}

.page-about .about-evolution__col > p {
  margin: 0 0 1rem;
  font-family: var(--font-serif);
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--c-gray);
}

.page-about .about-evolution__details {
  width: 100%;
  font-size: 0.875rem;
}

.page-about .about-evolution__details summary {
  list-style: none;
  width: fit-content;
  cursor: pointer;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--c-orange);
  padding: 0.5rem 0;
  border-bottom: 1px solid transparent;
  transition: border-color 0.24s var(--ease);
}

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

.page-about .about-evolution__details summary:hover {
  border-bottom-color: var(--c-orange);
}

.page-about .about-evolution__details[open] summary {
  border-bottom: 1px solid rgba(11, 31, 58, 0.1);
}

.page-about .about-evolution__list {
  margin: 0.875rem 0 0;
  padding: 0 0 0 1.125rem;
  display: grid;
  gap: 0.375rem;
  font-size: 0.875rem;
  line-height: 1.65;
  color: var(--c-ink);
}

.page-about .about-evolution__note {
  max-width: 36em;
  margin: 1.5rem auto 0;
  padding: 0 0.25rem;
  font-family: var(--font-serif);
  font-size: 1rem;
  line-height: 1.75;
  text-align: center;
  color: var(--c-bay);
}

/* ========== 服务范围 ========== */
.page-about .about-scope {
  margin-bottom: 5rem;
}

.page-about .about-scope__cards {
  display: grid;
  gap: 1rem;
  margin-bottom: 1.5rem;
}

.page-about .about-scope__item {
  position: relative;
  padding: 1.5rem;
  border-radius: var(--r-md);
  background: #fff;
  box-shadow: var(--shadow-soft);
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease);
}

.page-about .about-scope__item:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-hover);
}

.page-about .about-scope__icon {
  display: inline-block;
  margin-bottom: 0.875rem;
  font-family: var(--font-mono);
  font-size: 2rem;
  font-weight: 800;
  line-height: 1;
  color: var(--c-orange);
}

.page-about .about-scope__item h3 {
  margin: 0 0 0.5rem;
  font-family: var(--font-sans);
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--c-deep);
}

.page-about .about-scope__item p {
  margin: 0;
  font-family: var(--font-serif);
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--c-gray);
}

.page-about .about-scope__visual {
  margin-bottom: 1.5rem;
  border-radius: var(--r-md);
  overflow: hidden;
  box-shadow: var(--shadow-soft);
}

.page-about .about-scope__visual img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .about-scope__promise {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1.5rem;
  padding: 2rem 1.5rem;
  border-radius: var(--r-lg);
  background: linear-gradient(135deg, var(--c-deep) 0%, var(--c-bay) 100%);
  color: #fff;
}

.page-about .about-scope__promise-copy {
  max-width: 34em;
}

.page-about .about-scope__promise h3 {
  margin: 0 0 0.5rem;
  font-family: var(--font-sans);
  font-size: 1.25rem;
  font-weight: 700;
}

.page-about .about-scope__promise p {
  margin: 0;
  font-family: var(--font-serif);
  font-size: 0.9375rem;
  line-height: 1.75;
  color: rgba(255, 255, 255, 0.88);
}

.page-about .about-scope__promise-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

/* ========== 发展里程碑 ========== */
.page-about .about-milestones {
  margin-bottom: 5rem;
  padding: 1.5rem 0;
  border-radius: var(--r-lg);
  background: linear-gradient(180deg, rgba(245, 242, 237, 0) 0%, rgba(214, 234, 248, 0.45) 100%);
}

.page-about .about-milestones__layout {
  display: grid;
  gap: 2rem;
}

.page-about .about-milestones__timeline {
  position: relative;
  padding-left: 2.5rem;
}

.page-about .about-milestones__timeline::before {
  content: "";
  position: absolute;
  left: 13px;
  top: 6px;
  bottom: 6px;
  width: 2px;
  background: linear-gradient(to bottom, var(--c-gold) 0%, var(--c-azure) 55%, var(--c-orange) 100%);
}

.page-about .about-milestones__node {
  position: relative;
  margin-bottom: 2.25rem;
  transition: transform 0.3s var(--ease), box-shadow 0.3s var(--ease);
}

.page-about .about-milestones__node:hover {
  transform: translateY(-4px);
}

.page-about .about-milestones__dot {
  position: absolute;
  left: -2.5rem;
  top: 0.375rem;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--c-gold);
  border: 3px solid var(--c-warm);
  box-shadow: 0 0 0 2px var(--c-gold);
  transition: box-shadow 0.3s var(--ease);
}

.page-about .about-milestones__node:hover .about-milestones__dot {
  box-shadow: 0 0 0 6px rgba(230, 179, 37, 0.35);
}

.page-about .about-milestones__node h3 {
  margin: 0 0 0.375rem;
  font-family: var(--font-sans);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--c-deep);
}

.page-about .about-milestones__node p {
  max-width: 34em;
  margin: 0;
  font-family: var(--font-serif);
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--c-gray);
}

.page-about .about-milestones__figure {
  margin: 0;
  padding: 1.75rem;
  border-radius: var(--r-md);
  background: #fff;
  box-shadow: var(--shadow-soft);
  text-align: center;
}

.page-about .about-milestones__figure img {
  display: block;
  width: 100%;
  max-width: 420px;
  height: auto;
  margin: 0 auto;
  border-radius: 12px;
  object-fit: cover;
}

.page-about .about-milestones__figure figcaption {
  margin-top: 0.875rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--c-gray);
  letter-spacing: 0.04em;
}

/* ========== 用户价值 ========== */
.page-about .about-value {
  position: relative;
  margin-bottom: 4rem;
  padding: 3rem 1.5rem;
  border-radius: var(--r-lg);
  background: linear-gradient(160deg, var(--c-deep) 0%, var(--c-bay) 100%);
  color: #fff;
  overflow: hidden;
  isolation: isolate;
}

.page-about .about-value::after {
  content: "VALUE";
  position: absolute;
  right: -0.5rem;
  bottom: -1rem;
  z-index: -1;
  font-family: var(--font-mono);
  font-size: clamp(4rem, 10vw, 7rem);
  font-weight: 800;
  letter-spacing: -0.04em;
  color: rgba(255, 255, 255, 0.05);
}

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

.page-about .about-value__index {
  color: var(--c-amber);
}

.page-about .about-value .section-head__title {
  color: #fff;
}

.page-about .about-value__stats {
  position: relative;
  z-index: 1;
  display: grid;
  gap: 1.25rem;
  margin: 2rem 0;
}

.page-about .about-value__stat {
  padding: 1.5rem;
  border-radius: var(--r-md);
  background: rgba(255, 255, 255, 0.08);
  border: 1px solid rgba(255, 255, 255, 0.12);
}

.page-about .about-value__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(2rem, 4vw, 3rem);
  font-weight: 800;
  line-height: 1.1;
  color: var(--c-amber);
}

.page-about .about-value__label {
  display: block;
  margin-top: 0.5rem;
  font-size: 0.8125rem;
  letter-spacing: 0.04em;
  color: rgba(255, 255, 255, 0.76);
}

.page-about .about-value__statement {
  position: relative;
  z-index: 1;
  max-width: 32em;
  margin: 2rem auto;
  font-family: var(--font-serif);
  font-size: 1.0625rem;
  line-height: 1.8;
  text-align: center;
  color: rgba(255, 255, 255, 0.88);
}

.page-about .about-value__links {
  position: relative;
  z-index: 1;
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  justify-content: center;
}

.page-about .about-value__ghost {
  border: 1px solid rgba(255, 255, 255, 0.5);
  color: #fff;
}

/* ========== 结尾 ========== */
.page-about .about-end {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1.25rem;
  margin-bottom: 3rem;
  padding: 1.5rem 0;
  border-top: 1px solid rgba(11, 31, 58, 0.08);
}

.page-about .about-end__text {
  max-width: 30em;
  margin: 0;
  font-family: var(--font-serif);
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--c-gray);
}

.page-about .about-end__link {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 700;
  text-decoration: none;
  color: var(--c-orange);
  padding-bottom: 2px;
  border-bottom: 2px solid rgba(255, 108, 47, 0.3);
  transition: border-color 0.24s var(--ease);
}

.page-about .about-end__link:hover {
  border-bottom-color: var(--c-orange);
}

/* ========== 桌面端 ========== */
@media (min-width: 900px) {
  .page-about .breadcrumb {
    margin: 1.5rem 0 2rem;
  }

  .page-about .about-hero {
    display: grid;
    grid-template-columns: minmax(0, 1.15fr) minmax(280px, 0.85fr);
    gap: 3rem;
    align-items: center;
    padding: 4rem 4rem;
  }

  .page-about .about-hero__lead {
    font-size: 1.125rem;
  }

  .page-about .about-hero__visual {
    margin-top: 0;
  }

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

  .page-about .about-identity__card {
    padding: 2rem;
  }

  .page-about .about-evolution {
    padding: 4rem 3rem;
  }

  .page-about .about-evolution__compare {
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
  }

  .page-about .about-evolution__col {
    padding: 2rem;
  }

  .page-about .about-scope__cards {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1.25rem;
    margin-bottom: 2rem;
  }

  .page-about .about-scope__promise {
    padding: 3rem 3rem;
  }

  .page-about .about-milestones {
    padding: 3rem 2rem;
  }

  .page-about .about-milestones__layout {
    grid-template-columns: 1.3fr 0.7fr;
    align-items: center;
    gap: 3rem;
  }

  .page-about .about-milestones__figure {
    padding: 2rem;
  }

  .page-about .about-value {
    padding: 4rem 3rem;
  }

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

  .page-about .about-value__stat {
    padding: 2rem;
  }
}

@media (max-width: 420px) {
  .page-about .about-hero {
    padding: 1.5rem 1rem;
  }

  .page-about .about-hero__actions .btn {
    width: 100%;
  }

  .page-about .about-evolution__col {
    padding: 1.25rem;
  }

  .page-about .about-identity__facts li {
    grid-template-columns: 1fr;
    gap: 0.25rem;
  }

  .page-about .about-value__links .btn {
    width: 100%;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-scope__item,
  .page-about .about-milestones__node,
  .page-about .about-value,
  .page-about .about-hero,
  .page-about .about-identity,
  .page-about .about-evolution,
  .page-about .about-scope,
  .page-about .about-milestones,
  .page-about .about-end {
    transition: none;
    transform: none;
  }

  .page-about .about-milestones__dot {
    transition: none;
  }
}