.page-about {
  --about-band: clamp(56px, 9vw, 128px);
  display: block;
  overflow-x: clip;
  background: var(--void);
  color: var(--text);
}

/* ============ 首屏 ============ */
.page-about .about-hero {
  position: relative;
  padding-top: clamp(18px, 3vw, 34px);
  padding-bottom: clamp(40px, 6vw, 76px);
  background:
    radial-gradient(88% 68% at 94% 2%, rgba(34, 224, 255, .11), transparent 58%),
    radial-gradient(66% 58% at 2% 98%, rgba(255, 106, 26, .08), transparent 62%);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--line) 10%, var(--line) 90%, transparent);
}

.page-about .about-hero .breadcrumb {
  margin: 0 0 clamp(20px, 3vw, 34px);
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(22px, 4vw, 44px);
  align-items: end;
}

@media (min-width: 920px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: clamp(28px, 4vw, 56px);
  }
}

.page-about .about-hero .eyebrow {
  margin: 0 0 clamp(12px, 1.6vw, 18px);
}

.page-about .about-hero h1 {
  margin: 0;
  font-family: var(--font-head);
  font-size: var(--fs-hero);
  font-weight: 800;
  line-height: 1.06;
  letter-spacing: -.02em;
  color: var(--text);
}

.page-about .about-hero__lede {
  margin: clamp(16px, 2.4vw, 24px) 0 0;
  max-width: 44ch;
  color: var(--dim);
  font-size: var(--fs-body);
  line-height: 1.8;
}

.page-about .about-hero__cta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(22px, 3vw, 32px);
}

.page-about .about-hero__visual {
  position: relative;
  margin: 0;
  border: 1px solid var(--line);
  background: var(--panel);
}

.page-about .about-hero__visual::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--cyan), var(--pulse));
}

.page-about .about-hero__visual img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 4 / 5;
  object-fit: cover;
}

.page-about .about-hero__visual .media-frame__caption {
  padding: 10px clamp(12px, 1.6vw, 16px);
  border-top: 1px solid var(--line);
  color: var(--dim);
  font-size: var(--fs-note);
  line-height: 1.6;
}

/* 首屏数据条 */
.page-about .about-keyline {
  list-style: none;
  margin: clamp(28px, 4vw, 52px) 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

@media (min-width: 880px) {
  .page-about .about-keyline {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

.page-about .about-keyline li {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: clamp(14px, 2vw, 22px) clamp(14px, 1.8vw, 20px);
  background: var(--panel);
}

.page-about .about-keyline__num {
  font-family: var(--font-data);
  font-size: clamp(22px, 2.8vw, 32px);
  line-height: 1;
  letter-spacing: -.03em;
  color: var(--cyan);
}

.page-about .about-keyline__label {
  color: var(--dim);
  font-size: var(--fs-note);
  line-height: 1.6;
}

/* ============ 章节骨架 ============ */
.page-about .about-chapter {
  position: relative;
  padding-top: var(--about-band);
  padding-bottom: var(--about-band);
}

.page-about .about-chapter::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: min(440px, 64%);
  height: 2px;
  background: linear-gradient(90deg, var(--pulse), var(--cyan) 58%, transparent);
  opacity: .32;
  transform: scaleX(.26);
  transform-origin: left center;
  transition: transform 520ms cubic-bezier(.32, .72, .28, 1), opacity 280ms ease;
}

.page-about .about-chapter.is-active::before {
  opacity: 1;
  transform: scaleX(1);
}

.page-about .section-head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  align-items: start;
  column-gap: clamp(14px, 2.4vw, 28px);
  row-gap: 10px;
  margin: 0 0 clamp(28px, 4vw, 54px);
}

.page-about .section-num {
  grid-column: 1;
  grid-row: 1;
  font-family: var(--font-data);
  font-size: clamp(34px, 5.4vw, 62px);
  line-height: .82;
  letter-spacing: -.04em;
  color: var(--line);
  transition: color 320ms ease;
}

.page-about .about-chapter.is-active .section-num {
  color: var(--pulse);
}

.page-about .section-title {
  grid-column: 2;
  grid-row: 1;
  align-self: end;
  margin: 0;
  font-family: var(--font-head);
  font-size: var(--fs-h2);
  font-weight: 800;
  line-height: 1.14;
  letter-spacing: -.01em;
  color: var(--text);
}

.page-about .section-lead {
  grid-column: 2;
  grid-row: 2;
  margin: 0;
  max-width: 48ch;
  color: var(--dim);
  font-size: var(--fs-body);
  line-height: 1.78;
}

.page-about .prose p {
  margin: 0 0 1em;
  max-width: 42ch;
  color: var(--dim);
  font-size: var(--fs-body);
  line-height: 1.78;
}

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

/* ============ 01 ============ */
.page-about .about-why {
  display: grid;
  gap: clamp(20px, 3vw, 36px);
}

@media (min-width: 940px) {
  .page-about .about-why {
    grid-template-columns: minmax(0, 6fr) minmax(0, 5fr);
    align-items: start;
    gap: clamp(28px, 4vw, 56px);
  }
}

.page-about .about-why__panel {
  padding: clamp(18px, 2.4vw, 28px);
  border: 1px solid var(--line);
  border-left: 2px solid var(--pulse);
  background: var(--panel);
}

.page-about .about-why__title {
  margin: 14px 0 10px;
  font-family: var(--font-head);
  font-size: var(--fs-h3);
  letter-spacing: -.01em;
  color: var(--text);
}

.page-about .about-why__text {
  margin: 0 0 16px;
  color: var(--dim);
  font-size: var(--fs-note);
  line-height: 1.7;
}

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

.page-about .about-why__list li {
  padding: 10px 0 10px 14px;
  border-left: 1px solid var(--line);
  color: var(--dim);
  font-size: var(--fs-note);
  line-height: 1.65;
}

.page-about .about-why__list strong {
  display: inline-block;
  margin-right: 8px;
  font-family: var(--font-head);
  font-size: var(--fs-note);
  letter-spacing: .02em;
  color: var(--cyan);
}

/* ============ 02 版本时间线 ============ */
.page-about .about-version {
  margin: 0 0 clamp(24px, 3.4vw, 40px);
  border: 1px solid var(--line);
  background: var(--panel);
}

.page-about .about-version img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 14 / 9;
  object-fit: cover;
}

.page-about .about-version .media-frame__caption {
  padding: 10px clamp(12px, 1.6vw, 16px);
  border-top: 1px solid var(--line);
  color: var(--dim);
  font-size: var(--fs-note);
}

.page-about .tl {
  --tl-pad: clamp(22px, 4vw, 42px);
  --tl-axis: 8px;
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0 0 0 var(--tl-pad);
  display: grid;
  gap: clamp(8px, 1.2vw, 12px);
}

.page-about .tl::before {
  content: "";
  position: absolute;
  top: 4px;
  bottom: 4px;
  left: calc(var(--tl-axis) - 1px);
  width: 1px;
  background: linear-gradient(180deg, var(--cyan), var(--pulse) 52%, var(--line) 96%);
  opacity: .55;
}

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

.page-about .tl__item::before {
  content: "";
  position: absolute;
  top: 22px;
  left: calc(var(--tl-axis) - var(--tl-pad));
  width: calc(var(--tl-pad) - var(--tl-axis));
  height: 1px;
  background: var(--line);
}

.page-about .tl__node {
  background: var(--panel);
  border: 1px solid var(--line);
  transition: border-color var(--ease), background-color var(--ease);
}

.page-about .tl__node:hover {
  border-color: rgba(34, 224, 255, .55);
}

.page-about .tl__node[open] {
  border-color: var(--pulse);
  background: var(--lift);
}

.page-about .tl__head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr) 14px;
  align-items: center;
  gap: clamp(10px, 1.6vw, 18px);
  padding: clamp(12px, 1.5vw, 16px) clamp(13px, 1.7vw, 20px);
  cursor: pointer;
  list-style: none;
  outline-offset: 2px;
}

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

.page-about .tl__head:focus-visible {
  outline: 2px solid var(--cyan);
}

.page-about .tl__ver {
  font-family: var(--font-data);
  font-size: var(--fs-note);
  letter-spacing: .04em;
  color: var(--cyan);
  padding: 2px 7px;
  border: 1px solid var(--line);
  background: var(--void);
  transition: color var(--ease), border-color var(--ease);
}

.page-about .tl__node[open] .tl__ver {
  color: var(--pulse);
  border-color: rgba(255, 106, 26, .5);
}

.page-about .tl__name {
  font-family: var(--font-head);
  font-size: clamp(16px, 1.3vw, 19px);
  line-height: 1.4;
  letter-spacing: -.01em;
  color: var(--text);
}

.page-about .tl__mark {
  position: relative;
  justify-self: end;
  width: 12px;
  height: 12px;
  border: 1px solid var(--line);
  transition: border-color var(--ease), background-color var(--ease);
}

.page-about .tl__mark::before,
.page-about .tl__mark::after {
  content: "";
  position: absolute;
  background: var(--cyan);
  transition: transform var(--ease), background-color var(--ease);
}

.page-about .tl__mark::before {
  left: 50%;
  top: 2px;
  bottom: 2px;
  width: 1px;
  transform: translateX(-50%);
}

.page-about .tl__mark::after {
  top: 50%;
  left: 2px;
  right: 2px;
  height: 1px;
  transform: translateY(-50%);
}

.page-about .tl__node[open] .tl__mark {
  border-color: var(--pulse);
  background: rgba(255, 106, 26, .12);
}

.page-about .tl__node[open] .tl__mark::before {
  background: var(--pulse);
  transform: translateX(-50%) scaleY(0);
}

.page-about .tl__node[open] .tl__mark::after {
  background: var(--pulse);
}

.page-about .tl__body {
  margin: 0;
  max-width: 68ch;
  padding: clamp(12px, 1.5vw, 16px) clamp(13px, 1.7vw, 20px) clamp(14px, 1.8vw, 20px);
  border-top: 1px solid var(--line);
  color: var(--dim);
  font-size: var(--fs-body);
  line-height: 1.75;
}

.page-about .tl__node[open] .tl__body {
  animation: aboutNodeIn 200ms ease both;
}

@keyframes aboutNodeIn {
  from { opacity: 0; transform: translateY(-4px); }
  to { opacity: 1; transform: none; }
}

.page-about .about-version__note {
  margin: clamp(20px, 2.6vw, 30px) 0 0;
  padding-left: clamp(12px, 1.6vw, 18px);
  border-left: 2px solid var(--sage);
  max-width: 62ch;
  color: var(--dim);
  font-size: var(--fs-note);
  line-height: 1.75;
}

/* ============ 03 数据路径 ============ */
.page-about .pipe {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  grid-template-columns: minmax(0, 1fr);
}

@media (min-width: 720px) {
  .page-about .pipe {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 1080px) {
  .page-about .pipe {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

.page-about .pipe__step {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: clamp(18px, 2.2vw, 26px) clamp(16px, 1.8vw, 22px);
  background: var(--panel);
  transition: background-color var(--ease);
}

.page-about .pipe__step::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--cyan), transparent);
  transform: scaleX(0);
  transform-origin: left center;
  transition: transform 320ms cubic-bezier(.32, .72, .28, 1);
}

.page-about .pipe__step:hover {
  background: var(--lift);
}

.page-about .pipe__step:hover::after {
  transform: scaleX(1);
}

.page-about .pipe__idx {
  font-family: var(--font-data);
  font-size: var(--fs-note);
  letter-spacing: .18em;
  color: var(--sage);
}

.page-about .pipe__title {
  margin: 0;
  font-family: var(--font-head);
  font-size: var(--fs-h3);
  line-height: 1.3;
  letter-spacing: -.01em;
  color: var(--text);
}

.page-about .pipe__text {
  margin: 0;
  color: var(--dim);
  font-size: var(--fs-note);
  line-height: 1.7;
}

.page-about .about-refresh {
  display: grid;
  gap: 1px;
  margin-top: clamp(20px, 3vw, 34px);
  background: var(--line);
  border: 1px solid var(--line);
  grid-template-columns: minmax(0, 1fr);
}

@media (min-width: 760px) {
  .page-about .about-refresh {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

.page-about .about-refresh__item {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: clamp(16px, 2vw, 24px);
  background: var(--void);
}

.page-about .about-refresh__value {
  font-family: var(--font-data);
  font-size: clamp(24px, 3vw, 34px);
  line-height: 1;
  letter-spacing: -.03em;
  color: var(--pulse);
}

.page-about .about-refresh__label {
  color: var(--dim);
  font-size: var(--fs-note);
  line-height: 1.65;
}

/* ============ 04 团队 ============ */
.page-about .about-team {
  margin: 0 0 clamp(24px, 3.4vw, 40px);
  border: 1px solid var(--line);
  background: var(--panel);
}

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

.page-about .about-team .media-frame__caption {
  padding: 10px clamp(12px, 1.6vw, 16px);
  border-top: 1px solid var(--line);
  color: var(--dim);
  font-size: var(--fs-note);
}

.page-about .roles {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: clamp(12px, 1.8vw, 20px);
  grid-template-columns: minmax(0, 1fr);
}

@media (min-width: 780px) {
  .page-about .roles {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

.page-about .roles__item {
  padding: clamp(16px, 2vw, 24px);
  background: var(--panel);
  border: 1px solid var(--line);
  border-top: 2px solid var(--cyan);
  transition: transform var(--ease), background-color var(--ease), border-top-color var(--ease);
}

.page-about .roles__item:hover {
  transform: translateY(-2px);
  background: var(--lift);
  border-top-color: var(--pulse);
}

.page-about .roles__text {
  margin: 12px 0 0;
  color: var(--dim);
  font-size: var(--fs-body);
  line-height: 1.75;
}

/* ============ 05 生态与下一步 ============ */
.page-about .eco__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: clamp(12px, 1.8vw, 18px);
  grid-template-columns: minmax(0, 1fr);
}

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

.page-about .eco__item {
  display: grid;
  gap: 12px;
  align-content: start;
  padding: clamp(16px, 2vw, 22px);
  border: 1px solid var(--line);
  background: linear-gradient(180deg, var(--panel), var(--void));
}

.page-about .eco__text {
  margin: 0;
  color: var(--dim);
  font-size: var(--fs-note);
  line-height: 1.75;
}

.page-about .about-next {
  margin-top: clamp(28px, 4vw, 48px);
  padding-left: clamp(14px, 2vw, 22px);
  border-left: 2px solid var(--cyan);
}

.page-about .about-next__title {
  margin: 0 0 14px;
  font-family: var(--font-head);
  font-size: var(--fs-h3);
  letter-spacing: -.01em;
  color: var(--text);
}

.page-about .about-next__list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 10px;
  max-width: 66ch;
}

.page-about .about-next__list li {
  position: relative;
  padding-left: 18px;
  color: var(--dim);
  font-size: var(--fs-body);
  line-height: 1.75;
}

.page-about .about-next__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 12px;
  width: 8px;
  height: 1px;
  background: var(--pulse);
}

.page-about .about-paths {
  display: grid;
  gap: 1px;
  margin-top: clamp(28px, 4vw, 46px);
  background: var(--line);
  border: 1px solid var(--line);
  grid-template-columns: minmax(0, 1fr);
}

@media (min-width: 700px) {
  .page-about .about-paths {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 1100px) {
  .page-about .about-paths {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

.page-about .about-paths__item {
  display: grid;
  gap: 8px;
  padding: clamp(16px, 2vw, 22px);
  background: var(--panel);
  color: inherit;
  text-decoration: none;
  transition: background-color var(--ease);
}

.page-about .about-paths__item:hover {
  background: var(--lift);
}

.page-about .about-paths__item:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: -2px;
}

.page-about .about-paths__label {
  display: flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-head);
  font-size: var(--fs-h3);
  letter-spacing: -.01em;
  color: var(--text);
}

.page-about .about-paths__label::after {
  content: "→";
  font-family: var(--font-data);
  font-size: 14px;
  color: var(--cyan);
  transition: transform var(--ease);
}

.page-about .about-paths__item:hover .about-paths__label::after {
  transform: translateX(4px);
}

.page-about .about-paths__desc {
  color: var(--dim);
  font-size: var(--fs-note);
  line-height: 1.65;
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-chapter::before,
  .page-about .tl__node,
  .page-about .tl__mark,
  .page-about .roles__item,
  .page-about .pipe__step,
  .page-about .about-paths__label::after {
    transition: none;
  }
  .page-about .tl__node[open] .tl__body {
    animation: none;
  }
}