.page-about {
  --about-ink-text: #C9D6E4;
  --about-paper-ink: #12243A;
  --about-paper-muted: #5C6B7E;
  --about-paper-line: rgba(18, 36, 58, .18);
  background: var(--ink);
  color: var(--about-ink-text);
}

.page-about .about-hero {
  position: relative;
  background: var(--paper);
  color: var(--about-paper-ink);
  padding: clamp(24px, 5vw, 46px) 0 clamp(40px, 6vw, 78px);
  border-bottom: 4px solid var(--cyan);
}

.page-about .about-crumb a {
  color: var(--about-paper-muted);
  text-decoration: none;
}

.page-about .about-crumb a:hover {
  color: var(--orange);
}

.page-about .about-crumb .crumb-sep,
.page-about .about-crumb span[aria-current="page"] {
  color: var(--about-paper-muted);
}

.page-about .about-eyebrow {
  margin: clamp(26px, 4vw, 44px) 0 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .22em;
  text-transform: uppercase;
  color: var(--about-paper-muted);
}

.page-about .about-h1 {
  margin: 14px 0 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(34px, 7.4vw, 76px);
  line-height: 1.04;
  letter-spacing: -.02em;
  color: var(--about-paper-ink);
  max-width: 15em;
}

.page-about .about-lede {
  margin: 22px 0 0;
  max-width: 34em;
  font-size: clamp(16px, 1.6vw, 17px);
  line-height: 1.78;
  color: #2C3E55;
}

.page-about .about-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px 26px;
  margin: clamp(34px, 5vw, 52px) 0 0;
  padding: 0;
}

.page-about .about-fact {
  border-top: 1px solid var(--about-paper-line);
  padding-top: 12px;
  min-width: 0;
}

.page-about .about-fact dt {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--about-paper-muted);
}

.page-about .about-fact dd {
  margin: 8px 0 0;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(24px, 4.4vw, 36px);
  font-weight: 700;
  line-height: 1;
  color: var(--about-paper-ink);
}

.page-about .about-banner-wrap {
  max-width: 1400px;
  margin: 0 auto;
  padding: clamp(28px, 5vw, 56px) var(--gutter) 0;
}

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

.page-about .about-banner-frame {
  aspect-ratio: 1800 / 1000;
  background: var(--ink-2);
}

.page-about .media-frame img {
  display: block;
  width: 100%;
  height: 100%;
  max-width: 100%;
  object-fit: cover;
}

.page-about .about-banner .media-cap {
  margin-top: 12px;
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--muted);
}

.page-about .section {
  padding: clamp(52px, 8vw, 104px) 0;
}

.page-about .about-head {
  margin-bottom: clamp(30px, 4vw, 52px);
}

.page-about .about-head .chapter-num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .2em;
  text-transform: uppercase;
  color: var(--cyan);
}

.page-about .about-head .section-title {
  font-family: var(--font-display);
  font-weight: 700;
  letter-spacing: -.01em;
  line-height: 1.14;
  margin: 12px 0 0;
  color: #EDF3F9;
}

.page-about .about-head .section-lede {
  margin: 16px 0 0;
  max-width: 40em;
  font-size: 16px;
  line-height: 1.78;
  color: var(--muted);
}

/* 01 链路 */
.page-about .about-flow {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
}

.page-about .about-flow-step {
  position: relative;
  border-top: 1px solid var(--line);
  padding: 22px 0 26px;
}

.page-about .about-step-idx {
  display: block;
  font-family: var(--font-mono);
  font-size: 13px;
  font-variant-numeric: tabular-nums;
  letter-spacing: .12em;
  color: var(--amber);
}

.page-about .about-step-title {
  margin: 10px 0 8px;
  font-size: 20px;
  font-weight: 700;
  color: #EDF3F9;
}

.page-about .about-flow-step p {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--about-ink-text);
}

.page-about .about-flow-step::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -1px;
  width: 34px;
  height: 1px;
  background: var(--cyan);
  transition: width .28s var(--ease);
}

.page-about .about-flow-step:hover::after {
  width: 100%;
}

/* 02 节奏 */
.page-about .about-section--rhythm {
  background: var(--ink-2);
}

.page-about .about-rhythm {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0;
}

.page-about .about-rhythm-stat {
  border-top: 1px solid var(--line);
  padding: 22px 0 24px;
}

.page-about .about-rhythm-num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(42px, 9vw, 68px);
  font-weight: 700;
  line-height: 1;
  color: var(--amber);
}

.page-about .about-rhythm-unit {
  margin-left: 8px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .12em;
  color: var(--muted);
}

.page-about .about-rhythm-stat p {
  margin: 12px 0 0;
  max-width: 30em;
  font-size: 15px;
  line-height: 1.72;
  color: var(--about-ink-text);
}

.page-about .about-rhythm-note {
  margin: 32px 0 0;
  max-width: 46em;
  padding-left: 16px;
  border-left: 2px solid var(--cyan);
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--about-ink-text);
}

/* 03 分工 */
.page-about .about-team-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(28px, 4vw, 48px);
  align-items: start;
}

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

.page-about .about-team-btn {
  display: grid;
  grid-template-columns: 36px minmax(0, 1fr) auto 18px;
  grid-template-areas:
    "idx name count sign"
    ". track track track";
  align-items: center;
  column-gap: 12px;
  row-gap: 12px;
  width: 100%;
  padding: 20px 0;
  background: none;
  border: 0;
  border-top: 1px solid var(--line);
  color: inherit;
  font: inherit;
  text-align: left;
  cursor: pointer;
  transition: background .2s var(--ease);
}

.page-about .about-team-btn:hover {
  background: rgba(53, 224, 214, .05);
}

.page-about .about-team-btn .disclosure-idx {
  grid-area: idx;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--muted);
}

.page-about .about-team-name {
  grid-area: name;
  font-size: 18px;
  font-weight: 700;
  color: #EDF3F9;
}

.page-about .about-team-count {
  grid-area: count;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 13px;
  color: var(--cyan);
}

.page-about .about-team-track {
  grid-area: track;
  display: block;
  height: 4px;
  background: rgba(124, 140, 160, .22);
  overflow: hidden;
}

.page-about .about-team-fill {
  display: block;
  height: 100%;
}

.page-about .about-team-fill--a {
  width: 44%;
  background: var(--cyan);
}

.page-about .about-team-fill--b {
  width: 28%;
  background: var(--amber);
}

.page-about .about-team-fill--c {
  width: 28%;
  background: var(--green);
}

.page-about .disclosure-sign {
  grid-area: sign;
  position: relative;
  width: 14px;
  height: 14px;
}

.page-about .disclosure-sign::before,
.page-about .disclosure-sign::after {
  content: "";
  position: absolute;
  background: var(--cyan);
}

.page-about .disclosure-sign::before {
  left: 0;
  top: 6px;
  width: 14px;
  height: 2px;
}

.page-about .disclosure-sign::after {
  left: 6px;
  top: 0;
  width: 2px;
  height: 14px;
  transition: transform .22s var(--ease);
}

.page-about .about-team-btn[aria-expanded="true"] .disclosure-sign::after {
  transform: scaleY(0);
}

.page-about .disclosure-panel {
  padding: 2px 0 24px 48px;
  border-bottom: 1px solid var(--line);
}

.page-about .disclosure-panel p {
  margin: 0;
  max-width: 44em;
  font-size: 15px;
  line-height: 1.78;
  color: var(--about-ink-text);
}

.page-about .about-team-media {
  margin: 0;
}

.page-about .about-team-frame {
  aspect-ratio: 1200 / 800;
  background: var(--ink-2);
}

.page-about .about-team-media .media-cap {
  margin-top: 12px;
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--muted);
}

/* 04 足迹 */
.page-about .about-archive-top {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 4vw, 52px);
  align-items: start;
  margin-bottom: clamp(36px, 5vw, 64px);
}

.page-about .about-archive-media {
  margin: 0;
}

.page-about .about-archive-frame {
  aspect-ratio: 1000 / 1200;
  background: var(--ink-2);
}

.page-about .about-archive-media .media-cap {
  margin-top: 12px;
  font-size: 12.5px;
  line-height: 1.7;
  color: var(--muted);
}

.page-about .about-archive-intro p {
  margin: 0 0 18px;
  font-size: 16px;
  line-height: 1.82;
  color: var(--about-ink-text);
}

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

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

.page-about .about-rail {
  position: absolute;
  left: 27px;
  top: 28px;
  bottom: 28px;
  width: 2px;
  height: calc(100% - 56px);
  overflow: visible;
}

.page-about .about-rail line {
  stroke: var(--line);
  stroke-width: 2;
}

.page-about .about-node {
  display: grid;
  grid-template-columns: 56px minmax(0, 1fr);
  gap: 18px;
  padding: 24px 0 30px;
  border-bottom: 1px solid var(--line);
}

.page-about .about-node-dot {
  position: relative;
  z-index: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 56px;
  height: 56px;
  border-radius: 50%;
  border: 1px solid var(--cyan);
  background: var(--ink);
  color: var(--cyan);
  font-family: var(--font-mono);
  font-size: 13px;
  font-variant-numeric: tabular-nums;
  letter-spacing: .06em;
  transition: background .2s var(--ease), color .2s var(--ease), box-shadow .2s var(--ease);
}

.page-about .about-node:hover .about-node-dot {
  background: var(--cyan);
  color: var(--ink);
  box-shadow: 0 0 0 7px rgba(53, 224, 214, .12);
}

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

.page-about .about-node-meta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0 0 10px;
}

.page-about .about-node-code {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--muted);
}

.page-about .about-node-body h3 {
  margin: 0 0 10px;
  font-size: 20px;
  font-weight: 700;
  line-height: 1.3;
  color: #EDF3F9;
}

.page-about .about-node-body p {
  margin: 0 0 10px;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--about-ink-text);
}

.page-about .about-node-new {
  margin: 12px 0 0;
  font-size: 13px;
  color: var(--muted);
  font-family: var(--font-mono);
  letter-spacing: .02em;
}

.page-about .about-node-newlabel {
  display: inline-block;
  margin-right: 8px;
  padding: 2px 7px;
  background: rgba(255, 183, 51, .16);
  color: var(--amber);
  font-size: 11px;
  letter-spacing: .14em;
}

/* 05 校验（暖纸底） */
.page-about .about-section--check {
  background: var(--paper);
  color: var(--about-paper-ink);
}

.page-about .about-section--check .chapter-num {
  color: var(--orange);
}

.page-about .about-section--check .section-title {
  color: var(--about-paper-ink);
}

.page-about .about-section--check .section-lede {
  color: #40536B;
}

.page-about .about-prose p {
  margin: 0 0 20px;
  font-size: 16.5px;
  line-height: 1.85;
  color: #2C3E55;
}

.page-about .about-prose p:first-child::first-letter {
  float: left;
  margin: 6px 12px 0 0;
  font-family: var(--font-mono);
  font-size: 52px;
  line-height: .86;
  font-weight: 700;
  color: var(--orange);
}

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

/* 06 合作 */
.page-about .about-partner {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
}

.page-about .about-partner-item {
  border-top: 2px solid var(--cyan);
  padding: 22px 0 26px;
}

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

.page-about .about-partner-item:nth-child(3) {
  border-top-color: var(--green);
}

.page-about .about-partner-item h3 {
  margin: 0 0 10px;
  font-size: 19px;
  font-weight: 700;
  color: #EDF3F9;
}

.page-about .about-partner-item p {
  margin: 0;
  max-width: 34em;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--about-ink-text);
}

.page-about .about-partner-item a {
  color: var(--cyan);
}

/* 07 下一步 */
.page-about .about-next {
  background: var(--ink-2);
}

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

.page-about .about-next-item {
  border-top: 1px solid var(--line);
  padding: 22px 0 26px;
}

.page-about .about-next-item h3 {
  margin: 0 0 10px;
  font-size: 19px;
  font-weight: 700;
  color: #EDF3F9;
}

.page-about .about-next-item p {
  margin: 0 0 16px;
  max-width: 30em;
  font-size: 15px;
  line-height: 1.76;
  color: var(--about-ink-text);
}

.page-about .about-next-item--cyan {
  border-top-color: var(--cyan);
}

.page-about .about-next-item--orange {
  border-top-color: var(--orange);
}

.page-about .about-next-item--green {
  border-top-color: var(--green);
}

.page-about .about-next-item .link-more {
  color: var(--cyan);
}

.page-about .about-next-cta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 18px;
  margin-top: clamp(30px, 4vw, 46px);
}

.page-about .about-next-cta .link-more {
  color: var(--cyan);
}

@media (min-width: 620px) {
  .page-about .about-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-rhythm {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 0 clamp(20px, 3vw, 40px);
  }
}

@media (min-width: 760px) {
  .page-about .about-flow {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: clamp(24px, 3.5vw, 48px);
  }

  .page-about .about-partner {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 0 clamp(22px, 3vw, 42px);
  }

  .page-about .about-next-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 0 clamp(22px, 3vw, 42px);
  }
}

@media (min-width: 900px) {
  .page-about .about-team-layout {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, 1fr);
  }

  .page-about .about-archive-top {
    grid-template-columns: minmax(0, .85fr) minmax(0, 1.15fr);
  }

  .page-about .about-team-media {
    position: sticky;
    top: calc(var(--frame-h) + 24px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-flow-step::after,
  .page-about .about-node-dot,
  .page-about .disclosure-sign::after,
  .page-about .about-team-btn {
    transition: none;
  }
}