.page-about {
  padding-block: clamp(1.5rem, 4vw, 3rem) clamp(3rem, 6vw, 5rem);
  font-family: var(--font-body);
  color: var(--paper);
}

.page-about .about-masthead {
  display: grid;
  gap: clamp(1.5rem, 3vw, 2.5rem);
  padding-bottom: clamp(2rem, 4vw, 3rem);
  border-bottom: 1px solid var(--line);
}

.page-about .about-masthead__copy .breadcrumb {
  margin-bottom: 1rem;
}

.page-about .about-masthead h1 {
  margin: 0.7rem 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.9rem, 5vw, 3.3rem);
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--paper);
}

.page-about .about-masthead__lead {
  margin: 1.125rem 0 0;
  max-width: 42ch;
  font-size: clamp(0.9375rem, 1.6vw, 1.0625rem);
  line-height: 1.8;
  color: var(--mist);
}

.page-about .about-masthead__actions {
  margin-top: 1.75rem;
}

.page-about .about-masthead__visual {
  position: relative;
  margin: 0;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius-lg);
  box-shadow: 0 26px 60px -42px rgba(25, 230, 255, 0.6);
}

.page-about .about-masthead__visual::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background: linear-gradient(155deg, rgba(25, 230, 255, 0.16), transparent 46%, rgba(6, 20, 33, 0.55));
}

.page-about .about-masthead__visual img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
}

.page-about .about-layout {
  display: grid;
  gap: clamp(1.75rem, 3vw, 2.5rem);
  margin-top: clamp(2rem, 4vw, 3rem);
}

/* ---------- 左侧时间轴 ---------- */
.page-about .about-rail__title {
  margin: 0 0 1.1rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--gold);
}

.page-about .rail-timeline {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0 0 0 1.5rem;
}

.page-about .rail-timeline::before {
  content: "";
  position: absolute;
  left: 0.5rem;
  top: 0.4rem;
  bottom: 0.4rem;
  width: 1px;
  background: linear-gradient(180deg, var(--cyan-soft), var(--gold-soft) 62%, transparent);
}

.page-about .rail-node {
  position: relative;
  padding: 0.35rem 0 0.9rem;
  outline: none;
}

.page-about .rail-node::before {
  content: "";
  position: absolute;
  left: -1.28rem;
  top: 0.66rem;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--ink-950);
  border: 1px solid var(--cyan);
  transition: background 180ms var(--ease), box-shadow 180ms var(--ease);
}

.page-about .rail-node:hover::before,
.page-about .rail-node:focus::before {
  background: var(--cyan);
  box-shadow: 0 0 0 4px var(--cyan-ghost);
}

.page-about .rail-node:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 6px;
  border-radius: var(--radius-sm);
}

.page-about .rail-node__year {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.9375rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--cyan);
}

.page-about .rail-node__label {
  display: block;
  margin-top: 0.1rem;
  font-size: 0.875rem;
  line-height: 1.5;
  color: var(--mist);
}

.page-about .rail-node__more {
  display: block;
  max-height: 0;
  margin-top: 0;
  overflow: hidden;
  opacity: 0;
  font-size: 0.8125rem;
  line-height: 1.7;
  color: var(--paper);
  transition: max-height 240ms var(--ease), opacity 200ms var(--ease), margin-top 240ms var(--ease);
}

.page-about .rail-node:hover .rail-node__more,
.page-about .rail-node:focus .rail-node__more {
  max-height: 9rem;
  margin-top: 0.45rem;
  opacity: 1;
}

.page-about .about-rail__hint {
  margin: 1.1rem 0 0;
  padding-top: 0.9rem;
  border-top: 1px solid var(--line);
  font-size: 0.75rem;
  line-height: 1.65;
  color: var(--mist);
}

/* ---------- 右栏叙事 ---------- */
.page-about .about-block {
  padding-bottom: clamp(1.75rem, 3.5vw, 3rem);
  margin-bottom: clamp(1.75rem, 3.5vw, 2.75rem);
  border-bottom: 1px solid var(--line);
}

.page-about .about-block:last-child {
  padding-bottom: 0;
  margin-bottom: 0;
  border-bottom: 0;
}

.page-about .section-head h2 {
  margin: 0.4rem 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(1.375rem, 3vw, 1.875rem);
  line-height: 1.22;
  letter-spacing: -0.015em;
  color: var(--paper);
}

.page-about .prose {
  margin-top: 1.1rem;
  color: var(--mist);
  font-size: 0.9375rem;
  line-height: 1.8;
}

.page-about .prose p {
  margin: 0 0 0.9rem;
  max-width: 44ch;
}

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

.page-about .about-lede {
  margin: 1.1rem 0 0;
  max-width: 46ch;
  font-size: 0.9375rem;
  line-height: 1.8;
  color: var(--mist);
}

.page-about .about-subhead {
  margin: 1.75rem 0 0;
  font-size: 1rem;
  font-weight: 700;
  color: var(--paper);
}

/* 适用人群 */
.page-about .audience-grid {
  list-style: none;
  margin: 1.25rem 0 0;
  padding: 0;
  display: grid;
  gap: 0.875rem;
  grid-template-columns: 1fr;
}

.page-about .audience-card {
  position: relative;
  padding: 1.15rem 1.15rem 1.25rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--glass);
  transition: transform 180ms var(--ease), border-color 180ms var(--ease), background 180ms var(--ease);
}

.page-about .audience-card:hover {
  transform: translateY(-2px);
  border-color: var(--cyan-soft);
  background: var(--glass-2);
}

.page-about .audience-card__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.16em;
  color: var(--gold);
}

.page-about .audience-card h3 {
  margin: 0.45rem 0 0;
  font-size: 1rem;
  font-weight: 700;
  line-height: 1.4;
  color: var(--paper);
}

.page-about .audience-card p {
  margin: 0.5rem 0 0;
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--mist);
}

/* 发展历程 */
.page-about .about-figure {
  margin: 1.4rem 0 0;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.page-about .about-figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 14 / 9;
  object-fit: cover;
  opacity: 0.86;
}

.page-about .about-figure figcaption {
  padding: 0.7rem 1rem;
  font-size: 0.75rem;
  line-height: 1.6;
  color: var(--mist);
  background: var(--ink-900);
  border-top: 1px solid var(--line);
}

.page-about .milestones {
  list-style: none;
  margin: 1.25rem 0 0;
  padding: 0;
}

.page-about .milestone {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.3rem;
  padding: 1rem 0;
  border-bottom: 1px dashed var(--line);
}

.page-about .milestone:last-child {
  border-bottom: 0;
}

.page-about .milestone__year {
  font-family: var(--font-mono);
  font-size: 1.0625rem;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--cyan);
}

.page-about .milestone h3 {
  margin: 0;
  font-size: 0.9375rem;
  font-weight: 700;
  line-height: 1.45;
  color: var(--paper);
}

.page-about .milestone p {
  margin: 0.3rem 0 0;
  font-size: 0.9375rem;
  line-height: 1.72;
  color: var(--mist);
}

.page-about .about-note {
  margin: 1.25rem 0 0;
  padding: 1rem 1.15rem;
  border-left: 2px solid var(--gold-soft);
  border-radius: 0 var(--radius) var(--radius) 0;
  background: var(--glass);
}

.page-about .about-note p {
  margin: 0;
  font-size: 0.875rem;
  line-height: 1.75;
  color: var(--mist);
}

/* 团队四象限 */
.page-about .team-quad {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.875rem;
  margin-top: 1.4rem;
}

.page-about .team-card {
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--ink-900);
  transition: border-color 180ms var(--ease);
}

.page-about .team-card[open] {
  border-color: var(--cyan-soft);
}

.page-about .team-card__head {
  display: flex;
  align-items: baseline;
  gap: 0.75rem;
  padding: 1rem 1.1rem;
  cursor: pointer;
  list-style: none;
}

.page-about .team-card__head::-webkit-details-marker {
  display: none;
}

.page-about .team-card__head::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 1rem;
  color: var(--cyan);
}

.page-about .team-card[open] .team-card__head::after {
  content: "−";
}

.page-about .team-card__num {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  color: var(--gold);
}

.page-about .team-card__name {
  font-size: 1rem;
  font-weight: 700;
  color: var(--paper);
}

.page-about .team-card p {
  margin: 0;
  padding: 0 1.1rem 1.1rem;
  font-size: 0.9375rem;
  line-height: 1.72;
  color: var(--mist);
}

.page-about .rhythm-list {
  list-style: none;
  margin: 1.4rem 0 0;
  padding: 0;
  display: grid;
  gap: 0.8rem;
}

.page-about .rhythm-list li {
  position: relative;
  padding-left: 1.15rem;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--mist);
}

.page-about .rhythm-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.66em;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--cyan);
}

.page-about .rhythm-list strong {
  margin-right: 0.4rem;
  color: var(--paper);
}

/* 多屏设计原则 */
.page-about .split-row {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1.25rem;
  margin-top: 1.4rem;
}

.page-about .split-row__media {
  margin: 0;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
}

.page-about .split-row__media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  opacity: 0.88;
}

.page-about .principle-list {
  list-style: none;
  margin: 1.4rem 0 0;
  padding: 0;
}

.page-about .principle {
  display: grid;
  grid-template-columns: 2.25rem minmax(0, 1fr);
  gap: 0.5rem 0.85rem;
  padding: 0.95rem 0;
  border-top: 1px solid var(--line);
}

.page-about .principle:last-child {
  border-bottom: 1px solid var(--line);
}

.page-about .principle__num {
  font-family: var(--font-mono);
  font-size: 0.9375rem;
  font-weight: 700;
  color: var(--gold);
}

.page-about .principle h3 {
  margin: 0;
  font-size: 0.9375rem;
  font-weight: 700;
  color: var(--paper);
}

.page-about .principle p {
  margin: 0.28rem 0 0;
  font-size: 0.9375rem;
  line-height: 1.72;
  color: var(--mist);
}

/* 帮助资料 */
.page-about .stat-strip {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 0.5rem;
  margin-top: 1.35rem;
  padding: 1.1rem 0;
  border-top: 1px solid var(--line-strong);
  border-bottom: 1px solid var(--line-strong);
}

.page-about .stat__num {
  display: block;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(1.4rem, 4vw, 2rem);
  letter-spacing: -0.01em;
  color: var(--cyan);
}

.page-about .stat__label {
  display: block;
  margin-top: 0.3rem;
  font-size: 0.75rem;
  line-height: 1.5;
  color: var(--mist);
}

/* 承诺与联系 */
.page-about .promise-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.875rem;
  margin-top: 1.4rem;
}

.page-about .promise-card {
  padding: 1.2rem 1.2rem 1.3rem;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--ink-900);
}

.page-about .promise-card--glass {
  background: var(--glass);
  border-color: var(--cyan-soft);
}

.page-about .promise-card h3 {
  margin: 0;
  font-size: 0.9375rem;
  font-weight: 700;
  color: var(--paper);
}

.page-about .promise-card p {
  margin: 0.5rem 0 0;
  font-size: 0.9375rem;
  line-height: 1.72;
  color: var(--mist);
}

.page-about .contact-strip {
  display: grid;
  grid-template-columns: 1fr;
  margin-top: 1.35rem;
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--ink-900);
}

.page-about .contact-strip__item {
  padding: 1rem 1.1rem;
  border-top: 1px solid var(--line);
}

.page-about .contact-strip__item:first-child {
  border-top: 0;
}

.page-about .contact-strip__key {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--gold);
}

.page-about .contact-strip__value {
  display: block;
  margin-top: 0.35rem;
  font-size: 0.9375rem;
  line-height: 1.6;
  color: var(--paper);
  word-break: break-word;
}

.page-about .contact-note {
  margin: 0.9rem 0 0;
  font-size: 0.8125rem;
  line-height: 1.7;
  color: var(--mist);
}

.page-about .about-links {
  margin-top: 1.25rem;
}

/* ---------- 断点 ---------- */
@media (min-width: 620px) {
  .page-about .milestone {
    grid-template-columns: 5.25rem minmax(0, 1fr);
    column-gap: 1.25rem;
    align-items: start;
  }
}

@media (min-width: 640px) {
  .page-about .team-quad {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 720px) {
  .page-about .audience-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .audience-card--wide {
    grid-column: 1 / -1;
  }

  .page-about .promise-grid {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
  }

  .page-about .contact-strip {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .contact-strip__item {
    border-top: 0;
    border-left: 1px solid var(--line);
  }

  .page-about .contact-strip__item:first-child {
    border-left: 0;
  }
}

@media (min-width: 760px) {
  .page-about .split-row {
    grid-template-columns: minmax(0, 1fr) minmax(0, 0.85fr);
    align-items: start;
  }
}

@media (min-width: 900px) {
  .page-about .about-masthead {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    align-items: center;
  }
}

@media (min-width: 1000px) {
  .page-about .about-layout {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: clamp(2rem, 4vw, 4rem);
    align-items: start;
  }

  .page-about .about-rail {
    position: sticky;
    top: 6.5rem;
  }
}

@media (max-width: 999px) {
  .page-about .rail-node__more {
    max-height: none;
    margin-top: 0.4rem;
    opacity: 1;
  }

  .page-about .about-rail {
    padding-bottom: 0.5rem;
    border-bottom: 1px solid var(--line);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .rail-node__more,
  .page-about .audience-card,
  .page-about .team-card,
  .page-about .rail-node::before {
    transition: none;
  }

  .page-about .audience-card:hover {
    transform: none;
  }
}
<<<END>>>