.page-about {
  --about-idx-w: 200px;
  --about-gap: 56px;
  display: block;
  background: var(--snow);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(28px, 5vw, 56px) 0 clamp(48px, 7vw, 88px);
  background:
    linear-gradient(152deg, var(--frost) 0 52%, rgba(228, 236, 242, 0) 52%),
    var(--snow);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  right: 0;
  bottom: 0;
  width: 36%;
  height: 42%;
  background: linear-gradient(202deg, rgba(255, 122, 52, 0) 0 42%, rgba(255, 122, 52, 0.16) 42%);
  pointer-events: none;
}

.page-about .about-hero-inner {
  position: relative;
  z-index: 1;
  display: grid;
  gap: 32px;
}

.page-about .about-hero-copy h1 {
  margin: 10px 0 0;
  font-size: clamp(36px, 6.2vw, 82px);
  line-height: 1.03;
  letter-spacing: -0.02em;
  font-weight: 900;
  color: var(--ink);
  transform: skewX(-3deg);
  transform-origin: left bottom;
}

.page-about .about-hero-copy .lead {
  margin: 20px 0 0;
  max-width: 46ch;
  font-size: clamp(16px, 1.4vw, 18px);
  line-height: 1.8;
  color: var(--ink);
}

.page-about .about-hero-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 24px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-hero-visual {
  margin: 0;
}

.page-about .about-hero-visual .frame {
  aspect-ratio: 14 / 9;
  border: 1px solid var(--line);
}

.page-about .about-hero-visual img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.page-about .about-hero-visual .frame-caption {
  display: block;
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--stone);
}

@media (min-width: 900px) {
  .page-about .about-hero-inner {
    grid-template-columns: 7fr 5fr;
    align-items: end;
    gap: 48px;
  }
}

/* ---------- 主体骨架 ---------- */
.page-about .about-body {
  display: grid;
  gap: 40px;
  padding: clamp(48px, 6vw, 84px) 0 clamp(56px, 7vw, 96px);
}

@media (min-width: 1000px) {
  .page-about .about-body {
    grid-template-columns: var(--about-idx-w) minmax(0, 1fr);
    gap: var(--about-gap);
  }
}

.page-about .about-index {
  display: none;
}

@media (min-width: 1000px) {
  .page-about .about-index {
    display: block;
    position: sticky;
    top: 96px;
    align-self: start;
  }
}

.page-about .about-index-title {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--stone);
}

.page-about .about-index-list {
  margin: 0;
  padding: 0;
  list-style: none;
  counter-reset: about-idx;
  border-top: 1px solid var(--line);
}

.page-about .about-index-list li {
  counter-increment: about-idx;
}

.page-about .about-index-list a {
  position: relative;
  display: block;
  padding: 11px 0 11px 28px;
  font-size: 14px;
  line-height: 1.5;
  color: var(--stone);
  text-decoration: none;
  border-bottom: 1px solid var(--line);
  transition: color 0.22s var(--ease);
}

.page-about .about-index-list a::before {
  content: counter(about-idx, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 13px;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--line);
  transition: color 0.22s var(--ease);
}

.page-about .about-index-list a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 6px;
  width: 0;
  height: 2px;
  background: var(--ember);
  transition: width 0.24s var(--ease);
}

.page-about .about-index-list a:hover,
.page-about .about-index-list a:focus-visible {
  color: var(--ink);
}

.page-about .about-index-list a:hover::before,
.page-about .about-index-list a:focus-visible::before {
  color: var(--ice);
}

.page-about .about-index-list a:hover::after,
.page-about .about-index-list a:focus-visible::after {
  width: 16px;
}

.page-about .about-main {
  min-width: 0;
  display: grid;
  gap: clamp(44px, 5.5vw, 72px);
}

.page-about .about-section {
  border-top: 1px solid var(--line);
  padding-top: clamp(20px, 2.6vw, 32px);
  scroll-margin-top: 120px;
}

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

.page-about .about-section-head {
  display: grid;
  gap: 10px;
  margin-bottom: 24px;
}

.page-about .about-section-head h2 {
  margin: 0;
  font-size: clamp(25px, 3.4vw, 42px);
  line-height: 1.14;
  letter-spacing: -0.018em;
  font-weight: 900;
  color: var(--ink);
  max-width: 20ch;
}

.page-about .about-section-lede {
  margin: 0 0 26px;
  max-width: 62ch;
  font-size: 17px;
  line-height: 1.8;
  color: var(--stone);
}

/* ---------- 品牌由来 ---------- */
.page-about .about-origin {
  display: grid;
  gap: 26px;
}

.page-about .about-origin-mark {
  margin: 0;
  font-size: clamp(21px, 2.3vw, 28px);
  line-height: 1.45;
  font-weight: 900;
  letter-spacing: -0.01em;
  color: var(--moss);
  border-left: 4px solid var(--ice);
  padding-left: 18px;
}

.page-about .about-origin-body p {
  margin: 0 0 1.1em;
  font-size: 17px;
  line-height: 1.82;
  color: var(--ink);
}

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

@media (min-width: 860px) {
  .page-about .about-origin {
    grid-template-columns: 4fr 8fr;
    gap: 40px;
    align-items: start;
  }
}

/* ---------- 时间轴 ---------- */
.page-about .about-rail {
  position: relative;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 26px 16px;
  margin-bottom: 34px;
}

@media (min-width: 660px) {
  .page-about .about-rail {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 30px;
  }

  .page-about .about-rail::before {
    content: "";
    position: absolute;
    left: 0;
    right: 0;
    top: 12px;
    height: 1px;
    background: linear-gradient(90deg, var(--ice) 0%, var(--ice) 68%, var(--line) 100%);
  }
}

.page-about .about-node {
  position: relative;
  display: grid;
  gap: 4px;
  padding-top: 34px;
  text-decoration: none;
  color: var(--ink);
}

.page-about .about-node::before {
  content: "";
  position: absolute;
  top: 6px;
  left: 0;
  width: 13px;
  height: 13px;
  border-radius: 50%;
  background: var(--snow);
  border: 2px solid var(--ice);
  transition: background 0.24s var(--ease), border-color 0.24s var(--ease), transform 0.24s var(--ease);
}

.page-about .about-node:hover::before,
.page-about .about-node:focus-visible::before {
  background: var(--ember);
  border-color: var(--ember);
  transform: scale(1.3);
}

.page-about .about-node:focus-visible {
  outline: 2px solid var(--ice);
  outline-offset: 4px;
}

.page-about .about-node-num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--ice-deep);
}

.page-about .about-node-label {
  font-size: 17px;
  font-weight: 900;
  color: var(--ink);
}

.page-about .about-stages {
  display: grid;
  gap: 18px;
}

@media (min-width: 820px) {
  .page-about .about-stages {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 22px;
  }
}

.page-about .about-stage {
  position: relative;
  background: var(--white);
  border: 1px solid var(--line);
  border-left: 4px solid var(--ice);
  padding: 22px 22px 24px;
  scroll-margin-top: 120px;
  transition: border-left-color 0.24s var(--ease);
}

.page-about .about-stage:hover {
  border-left-color: var(--ember);
}

.page-about .about-stage::after {
  content: "";
  position: absolute;
  top: 0;
  right: 0;
  width: 0;
  height: 0;
  border-style: solid;
  border-width: 0 20px 20px 0;
  border-color: transparent var(--frost) transparent transparent;
}

.page-about .about-stage-eyebrow {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--clay);
}

.page-about .about-stage h3 {
  margin: 0 0 10px;
  font-size: 19px;
  line-height: 1.4;
  font-weight: 900;
  color: var(--ink);
}

.page-about .about-stage p {
  margin: 0 0 12px;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--ink);
}

.page-about .about-stage-q {
  margin: 0;
  padding-top: 12px;
  border-top: 1px dashed var(--line);
  font-size: 14px;
  line-height: 1.7;
  color: var(--stone);
}

/* ---------- 增长折线 ---------- */
.page-about .about-chart {
  margin: 32px 0 0;
  padding: 20px 16px 14px;
  background: var(--white);
  border: 1px solid var(--line);
}

.page-about .about-chart svg {
  display: block;
  width: 100%;
  height: auto;
}

.page-about .about-chart-grid {
  stroke: var(--line);
  stroke-width: 1;
}

.page-about .about-chart-line {
  fill: none;
  stroke-width: 3;
  stroke-linecap: round;
}

.page-about .about-chart-line--ice {
  stroke: var(--ice);
}

.page-about .about-chart-line--ember {
  stroke: var(--ember);
  stroke-dasharray: 7 6;
}

.page-about .about-dot {
  fill: var(--snow);
  stroke-width: 3;
}

.page-about .about-dot--ice {
  stroke: var(--ice);
}

.page-about .about-dot--ember {
  stroke: var(--ember);
}

.page-about .about-dot-label {
  font-family: var(--font-mono);
  font-size: 15px;
  fill: var(--ink);
}

.page-about .about-chart-tick {
  font-family: var(--font-mono);
  font-size: 12px;
  fill: var(--stone);
}

.page-about .about-chart-cap {
  display: flex;
  flex-wrap: wrap;
  gap: 18px;
  margin-top: 10px;
  padding-top: 12px;
  border-top: 1px solid var(--line);
  font-size: 13px;
  color: var(--stone);
}

.page-about .about-legend {
  display: inline-flex;
  align-items: center;
  gap: 8px;
}

.page-about .about-legend-swatch {
  display: inline-block;
  width: 20px;
  height: 3px;
}

.page-about .about-legend-swatch--ice {
  background: var(--ice);
}

.page-about .about-legend-swatch--ember {
  background: var(--ember);
}

.page-about .about-timeline-figure {
  margin: 32px 0 0;
}

.page-about .about-timeline-figure .frame {
  aspect-ratio: 16 / 9;
  border: 1px solid var(--line);
}

.page-about .about-timeline-figure img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.page-about .about-timeline-figure .frame-caption {
  display: block;
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--stone);
}

@media (min-width: 820px) {
  .page-about .about-chart {
    margin-top: 40px;
  }

  .page-about .about-timeline-figure {
    max-width: 620px;
    margin-top: 40px;
  }
}

/* ---------- 团队 ---------- */
.page-about .about-team {
  display: grid;
  gap: 26px;
}

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

.page-about .about-team-figure .frame {
  aspect-ratio: 3 / 2;
  border: 1px solid var(--line);
}

.page-about .about-team-figure img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.page-about .about-team-body p {
  margin: 0 0 20px;
  font-size: 17px;
  line-height: 1.82;
  color: var(--ink);
}

.page-about .about-team-list {
  margin: 0;
  border-top: 1px solid var(--line);
}

.page-about .about-team-row {
  display: grid;
  gap: 6px;
  padding: 16px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-team-row dt {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--ice-deep);
}

.page-about .about-team-row dd {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--ink);
}

@media (min-width: 860px) {
  .page-about .about-team {
    grid-template-columns: 5fr 7fr;
    gap: 40px;
    align-items: start;
  }

  .page-about .about-team-row {
    grid-template-columns: 96px minmax(0, 1fr);
    gap: 18px;
    align-items: baseline;
  }
}

/* ---------- 数据来源 ---------- */
.page-about .about-source-list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 0;
  border-top: 1px solid var(--line);
}

.page-about .about-source {
  display: grid;
  gap: 6px;
  padding: 22px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-source-label {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--stone);
}

.page-about .about-source-value {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(34px, 4.6vw, 52px);
  line-height: 1;
  font-weight: 700;
  color: var(--ink);
}

.page-about .about-source-value span {
  font-size: 15px;
  letter-spacing: 0.08em;
  color: var(--stone);
  margin-left: 6px;
}

.page-about .about-source h3 {
  margin: 4px 0 6px;
  font-size: 18px;
  line-height: 1.45;
  font-weight: 900;
  color: var(--ink);
}

.page-about .about-source p:last-child {
  margin: 0;
  max-width: 56ch;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--stone);
}

@media (min-width: 820px) {
  .page-about .about-source {
    grid-template-columns: 130px 150px minmax(0, 1fr);
    grid-template-rows: auto auto;
    align-items: baseline;
    gap: 6px 24px;
  }

  .page-about .about-source-label {
    grid-column: 1;
    grid-row: 1;
  }

  .page-about .about-source-value {
    grid-column: 2;
    grid-row: 1 / span 2;
  }

  .page-about .about-source h3 {
    grid-column: 3;
    grid-row: 1;
    margin: 0;
  }

  .page-about .about-source p:last-child {
    grid-column: 3;
    grid-row: 2;
  }
}

/* ---------- 资质 ---------- */
.page-about .about-certs {
  display: grid;
  gap: 20px;
}

@media (min-width: 800px) {
  .page-about .about-certs {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 24px;
  }
}

.page-about .about-cert {
  background: var(--white);
  border: 1px solid var(--line);
  border-top: 3px solid var(--clay);
  padding: 24px 22px 20px;
}

.page-about .about-cert .card-eyebrow {
  margin: 0 0 8px;
}

.page-about .about-cert h3 {
  margin: 0 0 10px;
  font-size: 20px;
  line-height: 1.4;
  font-weight: 900;
  color: var(--ink);
}

.page-about .about-cert > p:last-of-type {
  margin: 0 0 16px;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--ink);
}

.page-about .about-cert-details {
  border-top: 1px dashed var(--line);
  padding-top: 12px;
}

.page-about .about-cert-details summary {
  cursor: pointer;
  font-size: 14px;
  font-weight: 900;
  color: var(--ember-deep);
  list-style: none;
  padding-left: 20px;
  position: relative;
}

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

.page-about .about-cert-details summary::before {
  content: "＋";
  position: absolute;
  left: 0;
  top: 0;
  font-family: var(--font-mono);
  color: var(--ice-deep);
}

.page-about .about-cert-details[open] summary::before {
  content: "－";
}

.page-about .about-cert-details summary:focus-visible {
  outline: 2px solid var(--ice);
  outline-offset: 3px;
}

.page-about .about-cert-details ul {
  margin: 12px 0 0;
  padding: 0 0 0 18px;
  list-style: none;
}

.page-about .about-cert-details li {
  position: relative;
  margin-bottom: 8px;
  padding-left: 14px;
  font-size: 15px;
  line-height: 1.75;
  color: var(--stone);
}

.page-about .about-cert-details li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.7em;
  width: 6px;
  height: 2px;
  background: var(--ice);
}

/* ---------- 合作生态 ---------- */
.page-about .about-partners {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 0;
  border-top: 1px solid var(--line);
}

.page-about .about-partner {
  display: grid;
  gap: 8px;
  padding: 22px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-partner-num {
  font-family: var(--font-mono);
  font-size: 30px;
  line-height: 1;
  color: var(--ice);
}

.page-about .about-partner h3 {
  margin: 0 0 6px;
  font-size: 18px;
  line-height: 1.45;
  font-weight: 900;
  color: var(--ink);
}

.page-about .about-partner p {
  margin: 0;
  max-width: 56ch;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--stone);
}

@media (min-width: 720px) {
  .page-about .about-partner {
    grid-template-columns: 120px minmax(0, 1fr);
    gap: 28px;
    align-items: start;
  }

  .page-about .about-partner-num {
    font-size: 42px;
    color: var(--clay);
  }
}

/* ---------- 品牌色 ---------- */
.page-about .about-colors {
  display: grid;
  gap: 14px;
  background: var(--snow);
}

.page-about .about-color {
  padding: 28px 24px;
  color: var(--ink);
}

.page-about .about-color--ice {
  background: linear-gradient(140deg, #EDF7FC 0%, #D6EDF8 100%);
}

.page-about .about-color--ember {
  background: linear-gradient(140deg, #FFEDE1 0%, #FFD5BC 100%);
}

.page-about .about-color-title {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.16em;
  color: var(--ink);
}

.page-about .about-color p:last-child {
  margin: 0;
  font-size: 16px;
  line-height: 1.8;
  color: var(--ink);
}

.page-about .about-colors-note {
  margin: 18px 0 0;
  max-width: 60ch;
  font-size: 15.5px;
  line-height: 1.78;
  color: var(--stone);
}

@media (min-width: 760px) {
  .page-about .about-colors {
    grid-template-columns: 1fr 1fr;
    gap: 0;
  }

  .page-about .about-color {
    padding: 34px 30px;
  }

  .page-about .about-color--ice {
    clip-path: polygon(0 0, 100% 0, calc(100% - 44px) 100%, 0 100%);
    padding-right: 60px;
  }

  .page-about .about-color--ember {
    clip-path: polygon(44px 0, 100% 0, 100% 100%, 0 100%);
    padding-left: 66px;
  }
}

/* ---------- 结尾入口 ---------- */
.page-about .about-next {
  border-top: 1px solid var(--line);
  padding-top: clamp(20px, 2.6vw, 32px);
}

.page-about .about-next h2 {
  margin: 0 0 10px;
  font-size: clamp(22px, 2.6vw, 30px);
  line-height: 1.25;
  font-weight: 900;
  color: var(--ink);
}

.page-about .about-next p {
  margin: 0 0 20px;
  max-width: 56ch;
  font-size: 16px;
  line-height: 1.78;
  color: var(--stone);
}

.page-about .about-next-links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    transition-duration: 0.001ms !important;
  }
}