.page-about {
  --about-rail: 170px;
  --about-col-gap: clamp(28px, 5vw, 64px);
  --about-section-gap: clamp(56px, 9vw, 108px);
  --about-body-ink: #33424f;
}

.page-about .about-shell {
  padding-bottom: clamp(60px, 10vw, 120px);
}

.page-about .breadcrumb {
  margin-top: clamp(18px, 3vw, 30px);
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  padding-top: clamp(34px, 7vw, 82px);
  padding-bottom: clamp(30px, 5vw, 54px);
  max-width: 980px;
}

.page-about .about-hero h1 {
  margin: 16px 0 0;
  font-size: clamp(29px, 5.6vw, 50px);
  line-height: 1.15;
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--ink);
}

.page-about .about-hero__lead {
  margin: 22px 0 0;
  max-width: 44em;
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.78;
  color: var(--about-body-ink);
}

.page-about .about-hero__facts {
  list-style: none;
  margin: 30px 0 0;
  padding: 20px 0 0;
  border-top: 1px solid var(--line);
  display: flex;
  flex-wrap: wrap;
  gap: 12px 30px;
  font-size: 13.5px;
  color: var(--slate);
}

.page-about .about-hero__facts li {
  display: flex;
  align-items: baseline;
  gap: 8px;
}

.page-about .about-hero__facts .mono {
  font-size: 19px;
  font-weight: 700;
  color: var(--deep-sea);
  letter-spacing: -0.01em;
}

/* ---------- 双栏骨架 ---------- */

.page-about .about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--about-col-gap);
}

.page-about .about-rail {
  min-width: 0;
}

.page-about .about-rail__label {
  margin: 0;
  font-size: 11.5px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--slate);
}

.page-about .about-rail__list {
  list-style: none;
  margin: 12px 0 0;
  padding: 0 0 4px;
  display: flex;
  gap: 8px;
  overflow-x: auto;
  scrollbar-width: none;
  -webkit-overflow-scrolling: touch;
}

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

.page-about .about-rail__link {
  display: block;
  white-space: nowrap;
  padding: 8px 13px;
  border: 1px solid var(--line);
  border-radius: 2px;
  background: var(--paper);
  font-size: 13px;
  color: var(--ink);
  text-decoration: none;
  transition: border-color var(--t) var(--ease), color var(--t) var(--ease), background var(--t) var(--ease);
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  border-color: var(--gold);
  background: rgba(242, 193, 78, 0.14);
  color: var(--deep-sea);
}

.page-about .about-rail__link.is-active {
  border-color: var(--gold);
  background: var(--deep-sea);
  color: var(--mist);
}

/* ---------- 章节通用 ---------- */

.page-about .about-body {
  min-width: 0;
}

.page-about .about-section {
  padding-top: var(--about-section-gap);
  scroll-margin-top: calc(var(--header-total) + 24px);
}

.page-about .about-body > .about-section:first-child {
  padding-top: 0;
}

.page-about .about-section__head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--line);
}

.page-about .about-section__title {
  margin: 0;
  font-size: clamp(21px, 3.4vw, 30px);
  line-height: 1.28;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--ink);
}

.page-about .about-section__note {
  margin: 0;
  font-size: 11.5px;
  letter-spacing: 0.1em;
  color: var(--slate);
  white-space: nowrap;
}

.page-about .about-section__intro {
  margin: 24px 0 0;
  max-width: 42em;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--about-body-ink);
}

/* ---------- 品牌自述 ---------- */

.page-about .about-brand {
  display: grid;
  gap: 28px;
  margin-top: 26px;
}

.page-about .about-brand__text p {
  margin: 0 0 18px;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--about-body-ink);
}

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

.page-about .about-brand__media {
  margin: 0;
}

.page-about .about-brand__media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 14 / 9;
  object-fit: cover;
  clip-path: polygon(26px 0, 100% 0, 100% 100%, 0 100%, 0 26px);
  background: linear-gradient(150deg, var(--deep-sea), var(--trench));
}

.page-about .about-audience {
  list-style: none;
  margin: 34px 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-audience__item {
  background: var(--paper);
  padding: 22px 20px 24px;
  transition: background var(--t) var(--ease);
}

.page-about .about-audience__item:hover {
  background: var(--mist);
}

.page-about .about-audience__idx {
  display: inline-block;
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--gold-deep);
  padding-bottom: 8px;
}

.page-about .about-audience__title {
  margin: 0 0 8px;
  font-size: 16px;
  font-weight: 700;
  line-height: 1.45;
  color: var(--ink);
}

.page-about .about-audience__text {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--about-body-ink);
}

/* ---------- 版本时间线 ---------- */

.page-about .about-timeline {
  list-style: none;
  margin: 28px 0 0;
  padding: 6px 0 20px;
  display: flex;
  gap: 14px;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: thin;
}

.page-about .about-timeline__item {
  flex: 0 0 min(276px, 78vw);
  scroll-snap-align: start;
  display: flex;
}

.page-about .about-timeline__node {
  position: relative;
  width: 100%;
  background: var(--paper);
  border: 1px solid var(--line);
  padding: 26px 20px 22px;
  transition: border-color var(--t) var(--ease), box-shadow var(--t) var(--ease);
}

.page-about .about-timeline__node::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 64%;
  height: 3px;
  background: var(--line);
  transform: skewX(-24deg);
  transform-origin: left top;
  transition: background var(--t) var(--ease);
}

.page-about .about-timeline__node[open] {
  border-color: var(--gold);
  box-shadow: 0 12px 30px rgba(6, 40, 63, 0.1);
}

.page-about .about-timeline__node[open]::before {
  background: var(--gold);
}

.page-about .about-timeline__summary {
  display: flex;
  flex-direction: column;
  gap: 9px;
  cursor: pointer;
  list-style: none;
  outline-offset: 4px;
}

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

.page-about .about-timeline__ver {
  font-size: 27px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--gold-deep);
}

.page-about .about-timeline__name {
  font-size: 16px;
  font-weight: 700;
  line-height: 1.45;
  color: var(--ink);
}

.page-about .about-timeline__more {
  font-size: 12px;
  color: var(--slate);
}

.page-about .about-timeline__more::after {
  content: "查看这一版做了什么";
}

.page-about .about-timeline__node[open] .about-timeline__more::after {
  content: "收起这一版";
}

.page-about .about-timeline__body {
  margin: 16px 0 0;
  padding-top: 14px;
  border-top: 1px dashed var(--line);
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--about-body-ink);
}

.page-about .about-timeline__figure {
  margin: 24px 0 0;
}

.page-about .about-timeline__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 12 / 7;
  object-fit: cover;
  clip-path: polygon(0 0, calc(100% - 30px) 0, 100% 30px, 100% 100%, 30px 100%, 0 calc(100% - 30px));
  background: linear-gradient(130deg, var(--deep-sea), var(--trench));
}

/* ---------- 团队分工 ---------- */

.page-about .about-team {
  display: grid;
  gap: 14px;
  margin-top: 28px;
}

.page-about .about-team__panel {
  background: var(--paper);
  border: 1px solid var(--line);
  border-left: 3px solid var(--trench);
  padding: 22px 20px;
  transition: border-color var(--t) var(--ease), background var(--t) var(--ease);
}

.page-about .about-team__panel:nth-child(2) {
  border-left-color: var(--gold-deep);
}

.page-about .about-team__panel:nth-child(3) {
  border-left-color: var(--mint-deep);
}

.page-about .about-team__panel:hover {
  background: var(--mist);
}

.page-about .about-team__head {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
  cursor: pointer;
  list-style: none;
  outline-offset: 4px;
}

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

.page-about .about-team__name {
  font-size: 16px;
  font-weight: 700;
  color: var(--ink);
}

.page-about .about-team__count {
  font-size: 12.5px;
  color: var(--slate);
  white-space: nowrap;
}

.page-about .about-team__body {
  margin: 16px 0 0;
  padding-top: 14px;
  border-top: 1px solid var(--line);
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--about-body-ink);
}

/* ---------- 内容节奏 ---------- */

.page-about .about-routine {
  margin-top: 26px;
}

.page-about .about-routine__lead {
  margin: 0;
  max-width: 40em;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--about-body-ink);
}

.page-about .about-routine__list {
  list-style: none;
  margin: 30px 0 0;
  padding: 0;
  display: grid;
  gap: 22px;
}

.page-about .about-routine__item {
  position: relative;
  padding-left: 42px;
}

.page-about .about-routine__item::before {
  content: "";
  position: absolute;
  left: 14px;
  top: 6px;
  bottom: -22px;
  width: 1px;
  background: var(--line);
}

.page-about .about-routine__item:last-child::before {
  display: none;
}

.page-about .about-routine__code {
  position: absolute;
  left: 0;
  top: 2px;
  font-size: 12px;
  color: var(--gold-deep);
  letter-spacing: 0.06em;
  background: var(--mist);
  padding: 2px 0;
}

.page-about .about-routine__title {
  margin: 0 0 6px;
  font-size: 15.5px;
  font-weight: 700;
  color: var(--ink);
}

.page-about .about-routine__item p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--about-body-ink);
}

.page-about .about-routine__foot {
  margin: 30px 0 0;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--about-body-ink);
}

/* ---------- 协作生态 ---------- */

.page-about .about-eco {
  display: grid;
  gap: 26px;
  margin-top: 28px;
}

.page-about .about-eco__caption {
  margin: 0 0 12px;
  font-size: 11.5px;
  letter-spacing: 0.14em;
  color: var(--slate);
  text-transform: uppercase;
}

.page-about .about-eco__core {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .about-eco__core li {
  background: var(--deep-sea);
  color: var(--mist);
  padding: 15px 18px;
  font-size: 14px;
  clip-path: var(--bevel-sm);
}

.page-about .about-eco__partners {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .about-eco__partner {
  position: relative;
  background: var(--paper);
  border: 1px solid var(--line);
  padding: 20px 18px 22px;
  transition: border-color var(--t) var(--ease), transform var(--t) var(--ease);
}

.page-about .about-eco__partner:hover,
.page-about .about-eco__partner:focus-within {
  border-color: var(--gold);
  transform: translateY(-3px);
}

.page-about .about-eco__partner .tag {
  opacity: 0.6;
  transition: opacity var(--t) var(--ease);
}

.page-about .about-eco__partner:hover .tag,
.page-about .about-eco__partner:focus-within .tag {
  opacity: 1;
}

.page-about .about-eco__partner-title {
  margin: 14px 0 8px;
  font-size: 15px;
  font-weight: 700;
  line-height: 1.45;
  color: var(--ink);
}

.page-about .about-eco__partner p {
  margin: 0;
  font-size: 14px;
  line-height: 1.72;
  color: var(--about-body-ink);
}

.page-about .about-eco__figure {
  margin: 30px 0 0;
}

.page-about .about-eco__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  clip-path: polygon(30px 0, 100% 0, 100% calc(100% - 30px), calc(100% - 30px) 100%, 0 100%, 0 30px);
  background: linear-gradient(120deg, var(--trench), var(--deep-sea));
}

/* ---------- 资质 ---------- */

.page-about .about-cred {
  margin-top: 28px;
  background: var(--deep-sea);
  color: var(--mist);
  padding: clamp(26px, 4vw, 46px) clamp(22px, 3.5vw, 44px) clamp(24px, 3.5vw, 40px);
  clip-path: polygon(34px 0, 100% 0, 100% calc(100% - 34px), calc(100% - 34px) 100%, 0 100%, 0 34px);
}

.page-about .about-cred__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: rgba(244, 247, 250, 0.16);
}

.page-about .about-cred__item {
  background: var(--deep-sea);
  padding: 24px 20px;
}

.page-about .about-cred__num {
  display: block;
  font-size: 30px;
  font-weight: 700;
  line-height: 1;
  color: var(--gold);
  letter-spacing: -0.01em;
}

.page-about .about-cred__label {
  display: block;
  margin-top: 12px;
  font-size: 15px;
  font-weight: 700;
  color: var(--mist);
}

.page-about .about-cred__desc {
  margin: 8px 0 0;
  font-size: 13.5px;
  line-height: 1.7;
  color: rgba(244, 247, 250, 0.72);
}

.page-about .about-cred__icp {
  margin: 26px 0 0;
  font-size: 12.5px;
  letter-spacing: 0.06em;
  color: rgba(244, 247, 250, 0.66);
}

/* ---------- 联系指引 ---------- */

.page-about .about-reach {
  display: grid;
  gap: 1px;
  margin-top: 28px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-reach__block {
  background: var(--paper);
  padding: 28px clamp(20px, 3vw, 34px) 30px;
}

.page-about .about-reach__block--alt {
  background: var(--mist);
}

.page-about .about-reach__title {
  margin: 0 0 12px;
  font-size: 17px;
  font-weight: 700;
  line-height: 1.45;
  color: var(--ink);
}

.page-about .about-reach__block p {
  margin: 0 0 14px;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--about-body-ink);
}

.page-about .about-reach__actions {
  margin: 20px 0 0;
}

.page-about .about-reach__actions .btn,
.page-about .about-reach__actions .link-more {
  display: inline-block;
}

/* ---------- 响应式 ---------- */

@media (min-width: 620px) {
  .page-about .about-audience {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-routine__list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 26px 34px;
  }

  .page-about .about-routine__item::before {
    display: none;
  }

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

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

@media (min-width: 780px) {
  .page-about .about-team {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-brand {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
    align-items: start;
    gap: 40px;
  }
}

@media (min-width: 900px) {
  .page-about .about-eco {
    grid-template-columns: minmax(0, 280px) minmax(0, 1fr);
    gap: 38px;
    align-items: start;
  }

  .page-about .about-eco__partners {
    grid-template-columns: repeat(auto-fit, minmax(210px, 1fr));
  }
}

@media (min-width: 980px) {
  .page-about .about-layout {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
  }

  .page-about .about-rail {
    position: sticky;
    top: calc(var(--header-total) + 22px);
    align-self: start;
  }

  .page-about .about-rail__list {
    display: block;
    overflow: visible;
    margin-top: 14px;
    padding: 0;
  }

  .page-about .about-rail__list li + li {
    margin-top: 2px;
  }

  .page-about .about-rail__link {
    border: 0;
    border-left: 2px solid var(--line);
    border-radius: 0;
    background: transparent;
    padding: 8px 0 8px 14px;
    font-size: 13.5px;
    color: var(--slate);
    white-space: normal;
    line-height: 1.5;
  }

  .page-about .about-rail__link:hover,
  .page-about .about-rail__link:focus-visible {
    background: transparent;
    border-left-color: var(--gold);
    color: var(--ink);
  }

  .page-about .about-rail__link.is-active {
    background: transparent;
    border-left-color: var(--gold);
    color: var(--ink);
    font-weight: 600;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-rail__link,
  .page-about .about-timeline__node,
  .page-about .about-timeline__node::before,
  .page-about .about-team__panel,
  .page-about .about-audience__item,
  .page-about .about-eco__partner,
  .page-about .about-eco__partner .tag {
    transition: none;
  }

  .page-about .about-eco__partner:hover,
  .page-about .about-eco__partner:focus-within {
    transform: none;
  }
}