.page-about {
  --about-shadow: 0 30px 80px -52px rgba(51, 240, 206, 0.55);
  background:
    radial-gradient(120% 90% at 80% -12%, rgba(51, 240, 206, 0.15), transparent 62%),
    radial-gradient(90% 70% at -6% 34%, rgba(240, 181, 74, 0.08), transparent 66%),
    var(--ink);
  color: var(--paper);
  font-family: var(--font-body);
  padding: clamp(10px, 2vw, 20px) 0 clamp(48px, 8vw, 96px);
  overflow-x: hidden;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  display: grid;
  gap: 28px;
  padding-block: clamp(18px, 3.4vw, 34px) clamp(32px, 5.5vw, 62px);
}

.page-about .about-hero h1 {
  margin: 14px 0 0;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(34px, 6vw, 66px);
  line-height: 1.06;
  letter-spacing: 0.01em;
  color: var(--paper);
  max-width: 15em;
}

.page-about .about-hero .lede {
  margin: 18px 0 0;
  font-size: clamp(15px, 1.7vw, 17px);
  line-height: 1.85;
  color: rgba(243, 247, 240, 0.78);
  max-width: 62ch;
}

.page-about .about-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

.page-about .about-hero-media {
  position: relative;
  margin: 0;
  border-radius: var(--radius-l);
  overflow: hidden;
  border: 1px solid var(--line-soft);
  background: var(--green-deep);
  box-shadow: var(--about-shadow);
}

.page-about .about-hero-media::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 24px;
  background-image: repeating-linear-gradient(90deg, rgba(166, 255, 234, 0.6) 0 1px, transparent 1px 22px);
  opacity: 0.45;
  pointer-events: none;
  z-index: 2;
}

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

.page-about .about-hero-cap {
  padding: 10px 16px 12px;
  font-size: 12px;
  line-height: 1.6;
  letter-spacing: 0.02em;
  color: var(--gray);
}

/* ---------- 关键数字条 ---------- */
.page-about .about-stats {
  list-style: none;
  margin: 0 0 clamp(30px, 5.5vw, 58px);
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-m);
  overflow: hidden;
}

.page-about .about-stat {
  background: linear-gradient(160deg, rgba(20, 56, 44, 0.92), rgba(7, 11, 9, 0.96));
  padding: 18px 16px 16px;
  display: grid;
  gap: 6px;
  align-content: start;
}

.page-about .about-stat-num {
  font-family: var(--font-mono);
  font-size: clamp(23px, 3.4vw, 32px);
  line-height: 1;
  letter-spacing: 0.01em;
  color: var(--amber);
}

.page-about .about-stat-label {
  font-size: 12.5px;
  line-height: 1.5;
  letter-spacing: 0.04em;
  color: var(--gray);
}

/* ---------- 主体两栏 ---------- */
.page-about .about-body {
  display: grid;
  gap: 26px;
}

.page-about .about-rail-title {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.22em;
  color: var(--gray);
}

.page-about .about-rail-list {
  list-style: none;
  margin: 0;
  padding: 0 0 4px;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  scrollbar-width: none;
}

.page-about .about-rail-list::-webkit-scrollbar {
  display: none;
}

.page-about .about-rail-link {
  display: inline-flex;
  align-items: center;
  min-height: 44px;
  padding: 0 15px;
  border-radius: var(--radius-pill);
  border: 1px solid var(--line-soft);
  background: rgba(13, 36, 29, 0.72);
  color: var(--paper);
  font-size: 13.5px;
  white-space: nowrap;
  text-decoration: none;
  transition: color 0.2s ease, background 0.2s ease, border-color 0.2s ease;
}

.page-about .about-rail-link:hover,
.page-about .about-rail-link:focus-visible {
  color: var(--ink);
  background: var(--cyan);
  border-color: var(--cyan);
}

/* ---------- 章节 ---------- */
.page-about .chapter {
  padding-block: clamp(26px, 4.6vw, 44px);
  border-top: 1px solid var(--line-soft);
}

.page-about .chapter:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .chapter-head {
  display: flex;
  align-items: baseline;
  gap: 14px;
  margin-bottom: 18px;
}

.page-about .chapter-num {
  flex: none;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--cyan);
}

.page-about .chapter-head h2 {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(24px, 3.4vw, 38px);
  line-height: 1.16;
  letter-spacing: 0.01em;
  color: var(--paper);
}

.page-about .chapter-lede {
  margin: 0 0 22px;
  font-size: 15.5px;
  line-height: 1.8;
  color: rgba(243, 247, 240, 0.74);
  max-width: 60ch;
}

.page-about .chapter-card {
  padding: clamp(20px, 3.2vw, 32px);
  border-radius: var(--radius-l);
  border: 1px solid var(--line-soft);
  background: linear-gradient(155deg, rgba(20, 56, 44, 0.82), rgba(13, 36, 29, 0.55) 58%, rgba(7, 11, 9, 0.88));
  box-shadow: var(--about-shadow);
}

.page-about .chapter-card p {
  margin: 0 0 14px;
  font-size: 15.5px;
  line-height: 1.85;
  color: rgba(243, 247, 240, 0.86);
  max-width: 66ch;
}

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

.page-about .chapter-card .partner-legal {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--gray);
}

/* ---------- 起点：纸张标签卡 ---------- */
.page-about .origin-tags {
  list-style: none;
  margin: 20px 0 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .origin-tag {
  display: grid;
  gap: 8px;
  align-content: start;
  padding: 16px 16px 18px;
  border-radius: var(--radius-m);
  background: var(--cream);
  color: #16211B;
  box-shadow: 5px 5px 0 rgba(20, 56, 44, 0.9);
}

.page-about .origin-tag .tag {
  justify-self: start;
  padding: 3px 10px;
  border-radius: var(--radius-pill);
  background: #16211B;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.08em;
  color: var(--cyan);
}

.page-about .origin-tag .tag--amber {
  color: var(--amber);
}

.page-about .origin-tag .tag--signal {
  color: var(--signal);
}

.page-about .origin-tag h3 {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 19px;
  line-height: 1.3;
  letter-spacing: 0.01em;
}

.page-about .origin-tag p {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.75;
  color: #3C4A42;
}

/* ---------- 节奏：纵向刻度时间轴 ---------- */
.page-about .shift-list {
  list-style: none;
  margin: 0 0 4px;
  padding: 0 0 0 22px;
  border-left: 1px solid var(--line-strong);
}

.page-about .shift {
  position: relative;
  padding-bottom: 26px;
}

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

.page-about .shift::before {
  content: "";
  position: absolute;
  left: -26.5px;
  top: 7px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--cyan);
  box-shadow: 0 0 0 4px rgba(51, 240, 206, 0.14);
}

.page-about .shift-time {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.06em;
  color: var(--amber);
}

.page-about .shift h3 {
  margin: 7px 0 6px;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 21px;
  line-height: 1.3;
  color: var(--paper);
}

.page-about .shift p {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: rgba(243, 247, 240, 0.78);
  max-width: 62ch;
}

.page-about .chapter-note {
  margin-top: 24px;
  padding: 16px 18px;
  border-left: 2px solid var(--amber);
  border-radius: 0 var(--radius-s) var(--radius-s) 0;
  background: rgba(240, 181, 74, 0.07);
}

.page-about .chapter-note p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: rgba(243, 247, 240, 0.82);
  max-width: 66ch;
}

/* ---------- 图片框 ---------- */
.page-about .chapter-figure {
  margin: 0 0 22px;
  border-radius: var(--radius-l);
  overflow: hidden;
  border: 1px solid var(--line-soft);
  background: var(--green-deep);
}

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

.page-about .chapter-figure--paper img {
  aspect-ratio: 10 / 7;
}

.page-about .chapter-figure figcaption {
  padding: 10px 16px 12px;
  font-size: 12px;
  line-height: 1.6;
  color: var(--gray);
}

/* ---------- 团队分工 ---------- */
.page-about .role-list {
  display: grid;
  gap: 12px;
}

.page-about .role {
  padding: 14px 16px;
  border-radius: var(--radius-m);
  border: 1px solid var(--line-soft);
  background: linear-gradient(150deg, rgba(20, 56, 44, 0.7), rgba(7, 11, 9, 0.72));
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.page-about .role[open] {
  border-color: rgba(51, 240, 206, 0.42);
  box-shadow: 0 0 0 1px rgba(51, 240, 206, 0.12);
}

.page-about .role summary {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 4px 12px;
  min-height: 44px;
  align-content: center;
  cursor: pointer;
  list-style: none;
  color: var(--paper);
}

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

.page-about .role-num {
  font-family: var(--font-mono);
  font-size: 26px;
  line-height: 1;
  color: var(--cyan);
}

.page-about .role-name {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 19px;
  letter-spacing: 0.01em;
}

.page-about .role-hint {
  flex-basis: 100%;
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--gray);
}

.page-about .role p {
  margin: 12px 0 0;
  padding-top: 12px;
  border-top: 1px dashed var(--line-soft);
  font-size: 14px;
  line-height: 1.8;
  color: rgba(243, 247, 240, 0.8);
}

/* ---------- 里程碑 ---------- */
.page-about .timeline {
  position: relative;
  list-style: none;
  margin: 0 0 24px;
  padding: 0 0 0 22px;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 3px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: linear-gradient(180deg, var(--cyan), rgba(51, 240, 206, 0.06));
}

.page-about .timeline-item {
  position: relative;
  padding-bottom: 12px;
}

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

.page-about .timeline-dot {
  position: absolute;
  left: -23.5px;
  top: 19px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--green-turf);
  border: 1.5px solid var(--cyan);
  box-shadow: 0 0 0 4px rgba(51, 240, 206, 0.1);
}

.page-about .timeline-card {
  padding: 12px 16px;
  border-radius: var(--radius-m);
  border: 1px solid var(--line-soft);
  background: rgba(13, 36, 29, 0.55);
}

.page-about .timeline-card[open] {
  border-color: rgba(51, 240, 206, 0.36);
}

.page-about .timeline-card summary {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 4px 12px;
  min-height: 44px;
  align-content: center;
  cursor: pointer;
  list-style: none;
}

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

.page-about .timeline-year {
  font-family: var(--font-mono);
  font-size: 17px;
  letter-spacing: 0.06em;
  color: var(--amber);
}

.page-about .timeline-title {
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 19px;
  letter-spacing: 0.01em;
  color: var(--paper);
}

.page-about .timeline-card p {
  margin: 10px 0 0;
  padding-top: 10px;
  border-top: 1px dashed var(--line-soft);
  font-size: 14px;
  line-height: 1.8;
  color: rgba(243, 247, 240, 0.8);
}

/* ---------- 合作与资质 ---------- */
.page-about .partner-grid {
  display: grid;
  gap: 14px;
  margin-bottom: 16px;
}

.page-about .partner-card {
  display: grid;
  gap: 8px;
  align-content: start;
  padding: 20px;
  border-radius: var(--radius-l);
  border: 1px solid var(--line-soft);
  background: linear-gradient(160deg, rgba(20, 56, 44, 0.8), rgba(7, 11, 9, 0.82));
}

.page-about .partner-card .tag {
  justify-self: start;
}

.page-about .partner-num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(34px, 5vw, 46px);
  line-height: 1;
  color: var(--cyan);
}

.page-about .partner-card p:last-child {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: rgba(243, 247, 240, 0.8);
}

/* ---------- 服务承诺 ---------- */
.page-about .promise-list {
  list-style: none;
  margin: 0 0 26px;
  padding: 0;
  display: grid;
  gap: 18px;
}

.page-about .promise {
  padding-top: 14px;
  border-top: 2px solid var(--cyan);
}

.page-about .promise:nth-child(2) {
  border-top-color: var(--amber);
}

.page-about .promise:nth-child(3) {
  border-top-color: var(--signal);
}

.page-about .promise h3 {
  margin: 0 0 8px;
  font-family: var(--font-head);
  font-weight: 700;
  font-size: 19px;
  line-height: 1.35;
  color: var(--paper);
}

.page-about .promise p {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: rgba(243, 247, 240, 0.78);
}

.page-about .promise-contact {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 14px 18px;
  padding: clamp(20px, 3vw, 28px);
  border-radius: var(--radius-l);
  border: 1px solid var(--line-strong);
  background: linear-gradient(150deg, rgba(20, 56, 44, 0.9), rgba(13, 36, 29, 0.66));
}

.page-about .promise-contact p {
  flex: 1 1 270px;
  margin: 0;
  font-size: 14px;
  line-height: 1.85;
  color: rgba(243, 247, 240, 0.85);
  overflow-wrap: anywhere;
}

.page-about .promise-contact .mono {
  font-family: var(--font-mono);
  font-size: 13.5px;
  color: var(--cyan);
}

/* ---------- 断点 ---------- */
@media (min-width: 720px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

  .page-about .partner-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

@media (min-width: 860px) {
  .page-about .role-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 900px) {
  .page-about .about-hero {
    grid-template-columns: minmax(0, 1.14fr) minmax(0, 0.86fr);
    align-items: end;
    gap: 44px;
  }

  .page-about .about-hero-media {
    transform: translateY(6px);
  }
}

@media (min-width: 980px) {
  .page-about .about-body {
    grid-template-columns: 186px minmax(0, 1fr);
    gap: 54px;
    align-items: start;
  }

  .page-about .about-rail {
    position: sticky;
    top: 92px;
  }

  .page-about .about-rail-list {
    flex-direction: column;
    gap: 2px;
    padding-bottom: 0;
    overflow: visible;
  }

  .page-about .about-rail-link {
    justify-content: flex-start;
    min-height: 40px;
    padding: 0 0 0 14px;
    border: 0;
    border-left: 2px solid var(--line-soft);
    border-radius: 0;
    background: transparent;
    font-size: 14px;
    color: rgba(243, 247, 240, 0.8);
  }

  .page-about .about-rail-link:hover,
  .page-about .about-rail-link:focus-visible {
    background: transparent;
    border-left-color: var(--cyan);
    color: var(--cyan);
  }
}

@media (min-width: 1180px) {
  .page-about .chapter-head h2 {
    max-width: 20em;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-rail-link,
  .page-about .role {
    transition: none;
  }

  .page-about .about-hero-media {
    transform: none;
  }
}