.page-about {
  background: var(--navy-900);
  color: var(--ink);
}

.page-about .breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.5rem;
  padding: 1.25rem 0 0.5rem;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .breadcrumb a {
  color: var(--muted);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 0.12s var(--ease), border-color 0.12s var(--ease);
}

.page-about .breadcrumb a:hover,
.page-about .breadcrumb a:focus-visible {
  color: var(--orange-300);
  border-bottom-color: var(--orange-300);
}

.page-about .breadcrumb [aria-current="page"] {
  color: var(--ink);
}

/* ---------- 通用排版 ---------- */

.page-about .about-h2 {
  font-family: var(--font-display);
  font-size: clamp(1.75rem, 5.2vw, 2.125rem);
  line-height: 1.1;
  letter-spacing: -0.02em;
  margin: 0.5rem 0 0;
  color: var(--ink);
}

.page-about .about-h2--dark {
  color: var(--paper-ink);
}

.page-about .about-lead {
  margin: 1rem 0 0;
  max-width: 64ch;
  font-size: var(--fs-17);
  line-height: 1.75;
  color: var(--muted);
}

.page-about .about-lead--dark {
  color: #43566b;
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: 1.75rem 0 3rem;
}

.page-about .about-hero::before,
.page-about .about-hero::after {
  content: "";
  position: absolute;
  z-index: 0;
  pointer-events: none;
}

.page-about .about-hero::before {
  top: -5rem;
  right: -28%;
  width: 92%;
  height: 20rem;
  transform: rotate(-6deg);
  background: linear-gradient(
    90deg,
    transparent 0 44%,
    rgba(255, 90, 31, 0.18) 44% 61%,
    transparent 61% 100%
  );
}

.page-about .about-hero::after {
  bottom: -5rem;
  left: -22%;
  width: 74%;
  height: 13rem;
  transform: rotate(-6deg);
  background: linear-gradient(
    90deg,
    transparent 0 36%,
    rgba(61, 242, 140, 0.07) 36% 55%,
    transparent 55% 100%
  );
}

.page-about .about-hero > .container {
  position: relative;
  z-index: 1;
}

.page-about .about-hero__title {
  font-family: var(--font-display);
  font-size: clamp(2.35rem, 8.4vw, 5.25rem);
  line-height: 1.02;
  letter-spacing: -0.02em;
  max-width: 16ch;
  margin: 0.6rem 0 0;
  transform: rotate(-2deg);
  transform-origin: left center;
  color: var(--ink);
}

.page-about .about-hero__lead {
  margin: 1.75rem 0 0;
  max-width: 60ch;
  font-size: var(--fs-17);
  line-height: 1.8;
  color: var(--ink);
}

.page-about .hero-facts {
  list-style: none;
  margin: 2.25rem 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  border-top: 1px solid var(--line);
  border-left: 1px solid var(--line);
}

.page-about .hero-facts > li {
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  padding: 0.85rem 0.9rem;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.page-about .hero-facts__num {
  font-size: var(--fs-22);
  color: var(--ink);
}

.page-about .hero-facts__label {
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.14em;
  color: var(--muted);
}

/* ---------- 时间刻度 ---------- */

.page-about .about-timeline {
  position: relative;
  overflow: hidden;
  padding: 3rem 0 3.5rem;
  background: var(--navy-800);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.page-about .about-timeline__bg {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
  opacity: 0.16;
  pointer-events: none;
}

.page-about .about-timeline > .container {
  position: relative;
  z-index: 1;
}

.page-about .timeline {
  list-style: none;
  margin: 2.5rem 0 0;
  padding: 0 0 0 2.25rem;
  position: relative;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: linear-gradient(
    180deg,
    var(--orange-500) 0%,
    rgba(255, 90, 31, 0.35) 55%,
    rgba(255, 90, 31, 0.08) 100%
  );
}

.page-about .timeline__item {
  position: relative;
  padding-bottom: 2.25rem;
}

.page-about .timeline__item::before {
  content: "";
  position: absolute;
  left: -2.25rem;
  top: 0.55rem;
  width: 14px;
  height: 14px;
  border-radius: 50%;
  background: var(--navy-800);
  border: 2px solid var(--line);
  transition: background-color 0.12s var(--ease), border-color 0.12s var(--ease);
}

.page-about .timeline__item:hover::before,
.page-about .timeline__item:focus-within::before {
  border-color: var(--orange-500);
  background: var(--orange-500);
}

.page-about .timeline__item--live::before {
  border-color: var(--green-400);
  background: var(--green-400);
}

.page-about .timeline__item--next::before {
  border-color: var(--line);
  background: transparent;
}

.page-about .timeline__year {
  display: block;
  font-size: var(--fs-34);
  line-height: 1;
  color: var(--orange-300);
  letter-spacing: -0.02em;
}

.page-about .timeline__item--live .timeline__year {
  color: var(--green-400);
}

.page-about .timeline__item--next .timeline__year {
  color: var(--muted);
  font-size: var(--fs-22);
}

.page-about .timeline__title {
  margin: 0.5rem 0 0;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: var(--fs-22);
  color: var(--ink);
}

.page-about .timeline__text {
  margin: 0.6rem 0 0;
  max-width: 62ch;
  font-size: var(--fs-17);
  line-height: 1.78;
  color: var(--muted);
}

/* ---------- 团队 ---------- */

.page-about .about-team {
  padding: 3rem 0 3.5rem;
}

.page-about .media-frame {
  margin: 2rem 0 0;
  border: 1px solid var(--line);
  overflow: hidden;
  background: var(--navy-700);
}

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

.page-about .media-frame--square img {
  aspect-ratio: 10 / 7;
}

.page-about .media-frame__caption {
  padding: 0.75rem 0.9rem;
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.06em;
  color: var(--muted);
  border-top: 1px solid var(--line);
}

.page-about .roster {
  list-style: none;
  margin: 2rem 0 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.page-about .roster__item {
  padding: 1.15rem 0;
  border-bottom: 1px solid var(--line);
  transition: border-color 0.12s var(--ease);
}

.page-about .roster__item:hover,
.page-about .roster__item:focus-within {
  border-bottom-color: var(--orange-500);
}

.page-about .roster__head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 1rem;
}

.page-about .roster__name {
  margin: 0;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: var(--fs-22);
  color: var(--ink);
}

.page-about .roster__count {
  font-size: var(--fs-17);
  color: var(--orange-300);
}

.page-about .roster__bar {
  position: relative;
  height: 6px;
  margin-top: 0.85rem;
  background: var(--navy-700);
  border: 1px solid var(--line);
  overflow: hidden;
}

.page-about .roster__bar span {
  display: block;
  height: 100%;
  background: linear-gradient(90deg, var(--orange-500), var(--orange-300));
  transition: width 0.18s var(--ease);
}

.page-about .roster__item--edit .roster__bar span {
  width: 62.5%;
}

.page-about .roster__item--data .roster__bar span {
  width: 25%;
}

.page-about .roster__item--tech .roster__bar span {
  width: 12.5%;
}

.page-about .roster__duty {
  margin: 0.85rem 0 0;
  max-width: 66ch;
  font-size: var(--fs-17);
  line-height: 1.75;
  color: var(--muted);
}

/* ---------- 流程 ---------- */

.page-about .about-flow {
  padding: 3rem 0 3.5rem;
  background: var(--navy-700);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.page-about .flow {
  list-style: none;
  margin: 2.25rem 0 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

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

.page-about .flow__item summary {
  display: flex;
  align-items: center;
  gap: 1rem;
  padding: 1.1rem 0.25rem;
  cursor: pointer;
  list-style: none;
  transition: color 0.12s var(--ease);
}

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

.page-about .flow__item summary:hover .flow__name,
.page-about .flow__item summary:focus-visible .flow__name {
  color: var(--orange-300);
}

.page-about .flow__item[open] summary {
  border-bottom: 1px solid var(--line);
}

.page-about .flow__num {
  font-size: var(--fs-14);
  letter-spacing: 0.1em;
  color: var(--orange-300);
  flex: 0 0 auto;
}

.page-about .flow__name {
  flex: 1 1 auto;
  font-family: var(--font-display);
  font-size: var(--fs-22);
  letter-spacing: -0.01em;
  color: var(--ink);
  transition: color 0.12s var(--ease);
}

.page-about .flow__mark {
  position: relative;
  flex: 0 0 auto;
  width: 16px;
  height: 16px;
}

.page-about .flow__mark::before,
.page-about .flow__mark::after {
  content: "";
  position: absolute;
  background: var(--orange-500);
}

.page-about .flow__mark::before {
  left: 0;
  top: 7px;
  width: 16px;
  height: 2px;
}

.page-about .flow__mark::after {
  left: 7px;
  top: 0;
  width: 2px;
  height: 16px;
  transition: opacity 0.18s var(--ease);
}

.page-about .flow__item[open] .flow__mark::after {
  opacity: 0;
}

.page-about .flow__body {
  margin: 0;
  padding: 1rem 0.25rem 1.35rem 2.6rem;
  max-width: 66ch;
  font-size: var(--fs-17);
  line-height: 1.78;
  color: var(--muted);
}

/* ---------- 版本 ---------- */

.page-about .about-versions {
  padding: 3rem 0 3.5rem;
}

.page-about .versions {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  margin-top: 2rem;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .version {
  padding: 1.5rem 1.15rem 1.75rem;
  background: var(--navy-800);
  transition: background-color 0.12s var(--ease), box-shadow 0.12s var(--ease);
}

.page-about .version:hover,
.page-about .version:focus-within {
  background: var(--navy-700);
  box-shadow: inset 0 2px 0 0 var(--orange-500);
}

.page-about .version--current {
  background: var(--navy-700);
}

.page-about .version--current .version__tag {
  color: var(--green-400);
}

.page-about .version__tag {
  margin: 0;
  font-size: var(--fs-34);
  line-height: 1;
  color: var(--orange-300);
}

.page-about .version__name {
  margin: 0.65rem 0 0;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: var(--fs-22);
  color: var(--ink);
}

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

.page-about .version__list li {
  position: relative;
  padding: 0.55rem 0 0.55rem 1rem;
  font-size: var(--fs-14);
  line-height: 1.7;
  color: var(--muted);
  border-top: 1px solid var(--line);
}

.page-about .version__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 1.15rem;
  width: 6px;
  height: 1px;
  background: var(--orange-500);
}

.page-about .versions-note {
  margin-top: 2rem;
  padding: 1.5rem 1.15rem;
  border-left: 2px solid var(--orange-500);
  background: var(--navy-800);
}

.page-about .versions-note__title {
  margin: 0;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: var(--fs-22);
  color: var(--ink);
}

.page-about .versions-note p {
  margin: 0.75rem 0 0;
  max-width: 68ch;
  font-size: var(--fs-17);
  line-height: 1.78;
  color: var(--muted);
}

/* ---------- 生态 ---------- */

.page-about .about-ecosystem {
  padding: 3rem 0 3.5rem;
  background: var(--navy-800);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.page-about .eco-grid {
  margin-top: 2rem;
}

.page-about .eco-grid .media-frame {
  margin-top: 0;
}

.page-about .eco-body {
  margin-top: 1.5rem;
}

.page-about .eco-body p {
  margin: 0 0 1rem;
  max-width: 66ch;
  font-size: var(--fs-17);
  line-height: 1.78;
  color: var(--muted);
}

.page-about .eco-list {
  list-style: none;
  margin: 1.5rem 0 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.page-about .eco-list li {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  padding: 0.85rem 0;
  border-bottom: 1px solid var(--line);
}

.page-about .eco-list__key {
  font-family: var(--font-mono);
  font-size: var(--fs-12);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--orange-300);
}

.page-about .eco-list__val {
  font-size: var(--fs-17);
  line-height: 1.7;
  color: var(--ink);
}

/* ---------- 认可 ---------- */

.page-about .about-recognition {
  padding: 3rem 0 3.5rem;
  background: var(--paper);
  color: var(--paper-ink);
}

.page-about .about-recognition .eyebrow--muted {
  color: #5b6f83;
}

.page-about .rec-list {
  list-style: none;
  margin: 2rem 0 0;
  padding: 0;
  border-top: 1px solid rgba(11, 33, 56, 0.18);
}

.page-about .rec-item {
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
  padding: 1.25rem 0;
  border-bottom: 1px solid rgba(11, 33, 56, 0.18);
}

.page-about .rec-item__num {
  font-size: var(--fs-22);
  color: #b83a0c;
  letter-spacing: -0.01em;
}

.page-about .rec-item__text {
  margin: 0;
  max-width: 70ch;
  font-size: var(--fs-17);
  line-height: 1.78;
  color: var(--paper-ink);
}

.page-about .rec-contact {
  margin-top: 2rem;
  padding: 1.5rem 1.15rem;
  background: var(--paper-ink);
  color: var(--paper);
}

.page-about .rec-contact__title {
  margin: 0;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: var(--fs-22);
  color: var(--paper);
}

.page-about .rec-contact__text {
  margin: 0.75rem 0 0;
  max-width: 68ch;
  font-size: var(--fs-17);
  line-height: 1.78;
  color: #c6d6e3;
}

.page-about .rec-contact__text a {
  color: var(--orange-300);
  text-decoration: none;
  border-bottom: 1px solid rgba(255, 138, 92, 0.5);
  transition: border-color 0.12s var(--ease);
  word-break: break-all;
}

.page-about .rec-contact__text a:hover,
.page-about .rec-contact__text a:focus-visible {
  border-bottom-color: var(--orange-300);
}

/* ---------- 收尾 ---------- */

.page-about .about-cta {
  padding: 3rem 0 4.5rem;
}

.page-about .about-cta__links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
  margin-top: 2rem;
}

/* ---------- 响应式 ---------- */

@media (min-width: 640px) {
  .page-about .hero-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .eco-list li {
    flex-direction: row;
    align-items: baseline;
    gap: 1.5rem;
  }

  .page-about .eco-list__key {
    flex: 0 0 8.5rem;
  }
}

@media (min-width: 900px) {
  .page-about .breadcrumb {
    padding-top: 1.75rem;
  }

  .page-about .about-hero {
    padding: 2.5rem 0 4.5rem;
  }

  .page-about .about-hero__lead {
    margin-top: 2.25rem;
  }

  .page-about .about-timeline,
  .page-about .about-team,
  .page-about .about-flow,
  .page-about .about-versions,
  .page-about .about-ecosystem {
    padding-top: 4.5rem;
    padding-bottom: 5rem;
  }

  .page-about .about-recognition {
    padding: 4.5rem 0 5rem;
  }

  .page-about .about-cta {
    padding: 4.5rem 0 6rem;
  }

  .page-about .timeline {
    padding-left: 3rem;
  }

  .page-about .timeline__item::before {
    left: -3rem;
  }

  .page-about .timeline__item {
    padding-bottom: 3rem;
  }

  .page-about .timeline__year {
    font-size: var(--fs-56);
  }

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

  .page-about .version {
    padding: 2rem 1.5rem 2.25rem;
  }

  .page-about .versions-note {
    padding: 2rem 2rem 2rem 1.75rem;
  }

  .page-about .eco-grid {
    display: grid;
    grid-template-columns: 5fr 7fr;
    gap: 3rem;
    align-items: start;
  }

  .page-about .eco-body {
    margin-top: 0;
  }

  .page-about .rec-item {
    flex-direction: row;
    align-items: baseline;
    gap: 2rem;
  }

  .page-about .rec-item__num {
    flex: 0 0 7rem;
    font-size: var(--fs-34);
  }

  .page-about .rec-contact {
    padding: 2rem;
  }
}