.page-about {
  --pa-rail: rgba(46, 143, 168, 0.55);
  --pa-node: 14px;
  --pa-indent: 26px;
  padding-bottom: clamp(30px, 6vw, 72px);
}

/* ---------- 面包屑与首屏 ---------- */

.page-about .crumbs {
  padding-block: clamp(16px, 3vw, 30px);
  font-size: 12.5px;
  letter-spacing: 0.1em;
}

.page-about .page-about__head {
  padding-bottom: clamp(22px, 3.6vw, 44px);
  border-bottom: 1px solid var(--line);
}

.page-about .page-about__head h1 {
  font-family: var(--font-head);
  font-weight: 300;
  font-size: clamp(31px, 6.2vw, 72px);
  line-height: 1.06;
  letter-spacing: 0.004em;
  color: #E6EEEC;
  margin: 12px 0 0;
  max-width: 22ch;
}

.page-about .page-about__lede {
  margin: 20px 0 0;
  max-width: 64ch;
  font-size: 16px;
  line-height: 1.85;
  color: var(--text-dim);
}

/* ---------- 轨迹通栏图 ---------- */

.page-about .page-about__map {
  margin: clamp(24px, 4vw, 48px) 0 0;
}

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

/* ---------- 通用正文 ---------- */

.page-about p {
  font-size: 15.5px;
  line-height: 1.85;
  color: var(--text-dim);
}

.page-about h2 {
  font-family: var(--font-head);
  font-weight: 400;
  font-size: clamp(23px, 3.4vw, 38px);
  line-height: 1.18;
  letter-spacing: 0.005em;
  color: #E6EEEC;
  margin: 10px 0 0;
}

.page-about p a {
  color: var(--ice-300);
  text-decoration: none;
  border-bottom: 1px solid rgba(138, 212, 227, 0.35);
  transition: color var(--t) var(--ease), border-color var(--t) var(--ease);
}

.page-about p a:hover {
  color: var(--amber-400);
  border-bottom-color: var(--amber-400);
}

.page-about .section__head p {
  max-width: 62ch;
  margin-top: 12px;
}

/* ---------- 起文章节 ---------- */

.page-about .page-about__origin-grid {
  display: grid;
  gap: clamp(22px, 3.4vw, 48px);
}

.page-about .page-about__origin-text p {
  margin: 13px 0 0;
}

.page-about .page-about__origin-fig {
  margin: 0;
}

.page-about .page-about__origin-fig .media {
  border: 1px solid var(--line);
}

.page-about .page-about__origin-fig .media__cap {
  margin-top: 10px;
  font-size: 12.5px;
  letter-spacing: 0.06em;
  color: var(--stone-400);
}

/* ---------- 时间轴 ---------- */

.page-about .stages {
  position: relative;
  margin-top: clamp(24px, 3.6vw, 46px);
  padding-left: var(--pa-indent);
  display: grid;
  gap: clamp(16px, 2.6vw, 28px);
}

.page-about .stages::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 22px;
  bottom: 22px;
  width: 2px;
  background: linear-gradient(
    180deg,
    rgba(46, 143, 168, 0) 0%,
    rgba(46, 143, 168, 0.75) 10%,
    rgba(138, 212, 227, 0.38) 55%,
    rgba(232, 177, 74, 0.7) 100%
  );
}

.page-about .stage {
  position: relative;
}

.page-about .stage::before {
  content: "";
  position: absolute;
  left: calc(-1 * var(--pa-indent));
  top: 26px;
  width: var(--pa-node);
  height: var(--pa-node);
  transform: rotate(45deg);
  background: var(--ink-800);
  border: 2px solid var(--ice-600);
  transition: border-color var(--t) var(--ease), background var(--t) var(--ease);
}

.page-about .stage:last-child::before {
  border-color: var(--amber-400);
  background: rgba(232, 177, 74, 0.18);
}

.page-about .stage:hover::before {
  background: var(--ice-600);
}

.page-about .stage:last-child:hover::before {
  background: var(--amber-400);
}

.page-about .stage__panel {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
  padding: clamp(18px, 2.6vw, 28px);
  background: linear-gradient(150deg, rgba(30, 83, 72, 0.5) 0%, rgba(11, 27, 34, 0.9) 72%);
  border: 1px solid var(--line);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 16px), calc(100% - 16px) 100%, 0 100%);
}

.page-about .stage__panel::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 3px;
  background: var(--ice-600);
}

.page-about .stage:last-child .stage__panel::before {
  background: var(--amber-400);
}

.page-about .stage__side {
  order: -1;
}

.page-about .stage__year {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(24px, 4vw, 40px);
  font-weight: 600;
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--amber-400);
}

.page-about .stage h3 {
  font-family: var(--font-head);
  font-weight: 500;
  font-size: clamp(18px, 2.2vw, 23px);
  line-height: 1.3;
  color: #E6EEEC;
  margin: 0;
}

.page-about .stage p {
  margin: 9px 0 0;
}

/* ---------- 上线流程 ---------- */

.page-about .steps {
  list-style: none;
  margin: clamp(22px, 3.4vw, 42px) 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: rgba(138, 212, 227, 0.16);
  border: 1px solid var(--line);
}

.page-about .step {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: clamp(14px, 2.4vw, 30px);
  padding: clamp(18px, 2.4vw, 26px);
  background: var(--ink-800);
  transition: background var(--t) var(--ease);
}

.page-about .step:hover {
  background: rgba(18, 58, 51, 0.92);
}

.page-about .step__no {
  font-family: var(--font-mono);
  font-size: clamp(20px, 2.6vw, 28px);
  font-weight: 600;
  line-height: 1.15;
  letter-spacing: 0.02em;
  color: var(--ice-300);
}

.page-about .step__body h3 {
  font-family: var(--font-head);
  font-weight: 500;
  font-size: clamp(17px, 2vw, 21px);
  color: #E6EEEC;
  margin: 0;
}

.page-about .step__body p {
  margin: 8px 0 0;
}

/* ---------- 团队角色 ---------- */

.page-about .roles {
  margin-top: clamp(22px, 3.4vw, 42px);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(14px, 2vw, 22px);
}

.page-about .role {
  position: relative;
  padding: clamp(18px, 2.2vw, 24px);
  background: rgba(11, 27, 34, 0.72);
  border: 1px solid var(--line);
  border-top: 3px solid var(--ice-600);
  transition: transform var(--t) var(--ease), border-color var(--t) var(--ease), background var(--t) var(--ease);
}

.page-about .role:nth-child(1) { border-top-color: var(--ice-600); }
.page-about .role:nth-child(2) { border-top-color: var(--ice-300); }
.page-about .role:nth-child(3) { border-top-color: var(--amber-400); }
.page-about .role:nth-child(4) { border-top-color: var(--stone-400); }
.page-about .role:nth-child(5) { border-top-color: #4E8C7C; }

.page-about .role:hover {
  transform: translateY(-3px);
  background: rgba(18, 58, 51, 0.7);
  border-left-color: var(--line-2);
  border-right-color: var(--line-2);
  border-bottom-color: var(--line-2);
}

.page-about .role__head {
  display: flex;
  align-items: baseline;
  gap: 12px;
}

.page-about .role__n {
  font-family: var(--font-mono);
  font-size: clamp(26px, 3.4vw, 34px);
  font-weight: 600;
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--amber-400);
}

.page-about .role__name {
  font-family: var(--font-head);
  font-weight: 500;
  font-size: clamp(17px, 2vw, 20px);
  line-height: 1.3;
  color: #E6EEEC;
  margin: 0;
}

.page-about .role p {
  margin: 12px 0 0;
  font-size: 14.5px;
}

/* ---------- 内容厚度 ---------- */

.page-about .tally {
  margin-top: clamp(22px, 3.4vw, 42px);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: rgba(138, 212, 227, 0.18);
  border: 1px solid var(--line);
}

.page-about .tally__item {
  padding: clamp(20px, 2.6vw, 30px);
  background: rgba(11, 27, 34, 0.86);
}

.page-about .tally__v {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(38px, 5vw, 56px);
  font-weight: 600;
  line-height: 1;
  letter-spacing: -0.035em;
  color: var(--amber-400);
}

.page-about .tally__u {
  display: block;
  margin-top: 9px;
  font-family: var(--font-head);
  font-weight: 500;
  font-size: 15.5px;
  letter-spacing: 0.05em;
  color: #D9E2E0;
}

.page-about .tally__item p {
  margin: 10px 0 0;
  font-size: 14px;
  line-height: 1.8;
}

.page-about .page-about__tallynote {
  margin: clamp(20px, 3vw, 32px) 0 0;
  max-width: 70ch;
  font-size: 15px;
  line-height: 1.85;
  color: var(--stone-400);
}

/* ---------- 共建与认可 ---------- */

.page-about .page-about__partner-grid {
  display: grid;
  gap: clamp(24px, 3.6vw, 52px);
}

.page-about .page-about__partner-text p {
  margin: 14px 0 0;
}

.page-about .page-about__partner-fig {
  margin: 0;
}

.page-about .page-about__partner-fig .media {
  border: 1px solid var(--line);
}

.page-about .partners {
  list-style: none;
  margin: clamp(20px, 3vw, 30px) 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 10px 0;
  border-top: 1px solid var(--line);
  padding-top: clamp(16px, 2.4vw, 24px);
}

.page-about .partners li {
  position: relative;
  padding: 0 20px;
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.7;
  letter-spacing: 0.04em;
  color: var(--text);
}

.page-about .partners li::before {
  content: "/";
  position: absolute;
  left: 6px;
  color: var(--ice-600);
}

.page-about .partners li:first-child {
  padding-left: 0;
}

.page-about .partners li:first-child::before {
  display: none;
}

/* ---------- 收尾 ---------- */

.page-about .outro {
  padding: clamp(24px, 3.6vw, 44px);
  background: linear-gradient(120deg, rgba(18, 58, 51, 0.9) 0%, rgba(11, 27, 34, 0.95) 60%);
  border: 1px solid var(--line);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 22px), calc(100% - 22px) 100%, 0 100%);
}

.page-about .outro p {
  margin: 14px 0 0;
  max-width: 66ch;
}

.page-about .outro__links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(20px, 3vw, 30px);
}

/* ---------- 响应式 ---------- */

@media (min-width: 760px) {
  .page-about .page-about__origin-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: start;
  }

  .page-about .stage__panel {
    grid-template-columns: minmax(0, 1fr) 150px;
    gap: clamp(16px, 2.4vw, 36px);
    align-items: start;
    padding: clamp(22px, 2.6vw, 32px);
  }

  .page-about .stage__side {
    order: 0;
    text-align: right;
  }

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

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

  .page-about .page-about__partner-grid {
    grid-template-columns: minmax(0, 6fr) minmax(0, 4fr);
    align-items: center;
  }
}

@media (min-width: 1060px) {
  .page-about .roles {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .tally {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .page-about__head h1 {
    max-width: 20ch;
  }
}

@media (max-width: 560px) {
  .page-about .stages {
    padding-left: 20px;
  }

  .page-about .stages::before {
    left: 4px;
  }

  .page-about .stage::before {
    left: -20px;
    top: 22px;
    width: 12px;
    height: 12px;
  }

  .page-about .partners li {
    padding: 0 14px;
  }

  .page-about .partners li:first-child {
    padding-left: 0;
  }

  .page-about .outro__links .btn {
    flex: 1 1 100%;
    justify-content: center;
  }
}