.page-about {
  --about-rail: 188px;
  --about-hair: rgba(199, 211, 220, 0.2);
  --about-hair-soft: rgba(199, 211, 220, 0.1);
  --about-text: rgba(242, 239, 233, 0.82);
  --about-faint: rgba(242, 239, 233, 0.58);
  position: relative;
  padding-bottom: 104px;
}

.page-about::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 640px;
  background:
    radial-gradient(880px 380px at 16% -8%, rgba(53, 224, 200, 0.1), transparent 70%),
    radial-gradient(720px 320px at 90% 2%, rgba(196, 116, 79, 0.08), transparent 72%);
  pointer-events: none;
  z-index: 0;
}

.page-about > * {
  position: relative;
  z-index: 1;
}

/* ---------- 首屏 ---------- */

.page-about .about-intro {
  padding-top: 26px;
}

.page-about .about-intro .breadcrumb {
  margin-bottom: 24px;
}

.page-about .about-intro .eyebrow {
  margin: 0 0 14px;
}

.page-about h1 {
  font-family: var(--font-display);
  font-size: clamp(30px, 5.4vw, 52px);
  font-weight: 700;
  letter-spacing: 0.04em;
  line-height: 1.16;
  color: var(--cream);
  margin: 0 0 22px;
  max-width: 20ch;
}

.page-about .about-intro__lede {
  max-width: 62ch;
  margin: 0;
  font-size: var(--t-body);
  line-height: 1.8;
  color: var(--about-text);
}

.page-about .about-hero-media {
  margin: 46px auto 0;
  border-radius: 28px;
  overflow: hidden;
  position: relative;
  isolation: isolate;
}

.page-about .about-hero-media::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(11, 27, 43, 0) 42%, rgba(11, 27, 43, 0.82) 100%);
  pointer-events: none;
}

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

.page-about .about-hero-media img {
  aspect-ratio: 16 / 9;
}

/* ---------- 章节骨架 ---------- */

.page-about .about-chapter {
  margin-top: 84px;
}

.page-about .about-chapter--last {
  margin-top: 92px;
}

.page-about .about-split {
  display: grid;
  grid-template-columns: 1fr;
  gap: 22px;
}

.page-about .about-aside {
  display: flex;
  align-items: baseline;
  gap: 14px;
}

.page-about .about-aside__index {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 34px;
  font-weight: 700;
  line-height: 1;
  letter-spacing: 0.02em;
  color: rgba(53, 224, 200, 0.34);
}

.page-about .about-aside__label {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--rock);
}

.page-about h2 {
  font-family: var(--font-display);
  font-size: clamp(24px, 3.6vw, 34px);
  font-weight: 700;
  letter-spacing: 0.04em;
  line-height: 1.28;
  color: var(--cream);
  margin: 0 0 18px;
}

.page-about h3 {
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 700;
  letter-spacing: 0.03em;
  line-height: 1.45;
  color: var(--cream);
  margin: 0 0 10px;
}

.page-about .about-body p {
  max-width: 66ch;
  margin: 0 0 18px;
  font-size: var(--t-body);
  line-height: 1.78;
  color: var(--about-text);
}

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

.page-about .about-thesis {
  position: relative;
  padding-left: 16px;
  margin-bottom: 22px;
  font-size: 19px;
  line-height: 1.7;
  color: var(--cream);
}

.page-about .about-thesis::before {
  content: "";
  position: absolute;
  left: 0;
  top: 6px;
  bottom: 6px;
  width: 2px;
  border-radius: 2px;
  background: linear-gradient(180deg, var(--cyan), rgba(53, 224, 200, 0.15));
}

.page-about .about-body a:not(.btn) {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(53, 224, 200, 0.42);
  transition: border-color 120ms ease, color 120ms ease;
}

.page-about .about-body a:not(.btn):hover,
.page-about .about-body a:not(.btn):focus-visible {
  border-bottom-color: var(--cyan);
}

/* ---------- 同步节点条 ---------- */

.page-about .about-nodes {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: 28px;
}

.page-about .about-nodes__item {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  padding: 10px 18px;
  border-radius: 999px;
  border: 1px solid var(--about-hair);
  background: rgba(16, 42, 62, 0.62);
  font-size: var(--t-note);
  line-height: 1.5;
  color: var(--about-faint);
}

.page-about .about-nodes__item b {
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 700;
  color: var(--cyan);
  letter-spacing: 0.02em;
}

/* ---------- 大数字锚点 ---------- */

.page-about .about-lead-stat {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 4px 12px;
  margin: 0 0 24px;
  padding: 22px 24px 20px;
  border-radius: 22px;
  border: 1px solid var(--about-hair-soft);
  background:
    linear-gradient(135deg, rgba(53, 224, 200, 0.08), rgba(53, 224, 200, 0) 58%),
    rgba(16, 42, 62, 0.5);
}

.page-about .about-lead-stat__value {
  font-family: var(--font-mono);
  font-size: clamp(46px, 8vw, 72px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.01em;
  color: var(--cyan);
}

.page-about .about-lead-stat__unit {
  font-family: var(--font-mono);
  font-size: 16px;
  letter-spacing: 0.04em;
  color: var(--rock);
}

.page-about .about-lead-stat__note {
  flex: 1 1 100%;
  max-width: 58ch;
  margin: 8px 0 0;
  font-size: var(--t-note);
  line-height: 1.7;
  color: var(--about-faint);
}

/* ---------- 团队构成 ---------- */

.page-about .about-roster {
  list-style: none;
  margin: 4px 0 26px;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .about-roster__row {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 6px 14px;
  align-items: baseline;
}

.page-about .about-roster__name {
  font-size: 15px;
  color: var(--cream);
  letter-spacing: 0.02em;
}

.page-about .about-roster__num {
  font-family: var(--font-mono);
  font-size: 14px;
  color: var(--cyan);
}

.page-about .about-roster__bar {
  grid-column: 1 / -1;
  display: block;
  height: 6px;
  border-radius: 3px;
  background: rgba(199, 211, 220, 0.12);
  overflow: hidden;
}

.page-about .about-roster__bar > span {
  display: block;
  height: 100%;
  width: var(--w, 0);
  border-radius: 3px;
  background: linear-gradient(90deg, var(--cyan), rgba(53, 224, 200, 0.3));
  transition: width 640ms ease-out;
}

/* ---------- 章节图 ---------- */

.page-about .about-figure {
  margin: 40px auto 0;
}

.page-about .about-figure .media {
  position: relative;
  border-radius: 24px;
  overflow: hidden;
  background: var(--deep);
}

.page-about .about-figure .media__overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(11, 27, 43, 0) 48%, rgba(6, 16, 25, 0.86) 100%);
  pointer-events: none;
}

.page-about .about-figure .media__caption {
  position: absolute;
  left: 22px;
  right: 22px;
  bottom: 18px;
  margin: 0;
  font-size: var(--t-note);
  line-height: 1.6;
  color: rgba(242, 239, 233, 0.72);
}

/* ---------- 演进时间线 ---------- */

.page-about .about-timeline {
  list-style: none;
  margin: 30px 0 0;
  padding: 0;
  position: relative;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 10px;
  bottom: 34px;
  width: 2px;
  border-radius: 2px;
  background: linear-gradient(180deg, var(--cyan) 0%, rgba(53, 224, 200, 0.35) 55%, rgba(53, 224, 200, 0) 100%);
}

.page-about .about-timeline__node {
  position: relative;
  padding-left: 34px;
  padding-bottom: 34px;
  outline: none;
}

.page-about .about-timeline__node:last-child {
  padding-bottom: 0;
}

.page-about .about-timeline__dot {
  position: absolute;
  left: 0;
  top: 5px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  border: 2px solid var(--cyan);
  background: var(--abyss);
  box-shadow: 0 0 0 5px rgba(53, 224, 200, 0.09);
  transition: background-color 160ms ease, box-shadow 160ms ease;
}

.page-about .about-timeline__node:hover .about-timeline__dot,
.page-about .about-timeline__node:focus-visible .about-timeline__dot,
.page-about .about-timeline__node:focus-within .about-timeline__dot {
  background: var(--cyan);
  box-shadow: 0 0 0 7px rgba(53, 224, 200, 0.14);
}

.page-about .about-timeline__node:focus-visible {
  box-shadow: 0 0 0 2px var(--cyan);
  border-radius: 12px;
}

.page-about .about-timeline__stage {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--rock);
}

.page-about .about-timeline__node h3 {
  margin-bottom: 8px;
}

.page-about .about-timeline__node > p {
  max-width: 62ch;
  margin: 0;
  font-size: var(--t-body);
  line-height: 1.75;
  color: var(--about-text);
}

.page-about .about-timeline__detail {
  margin-top: 12px;
}

.page-about .about-timeline__detail ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 8px;
}

.page-about .about-timeline__detail li {
  position: relative;
  padding-left: 18px;
  font-size: var(--t-note);
  line-height: 1.65;
  color: var(--about-faint);
}

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

.page-about .about-timeline__foot {
  margin: 30px 0 0;
  padding-top: 18px;
  border-top: 1px solid var(--about-hair-soft);
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.7;
  letter-spacing: 0.02em;
  color: var(--rock);
}

/* ---------- 覆盖范围 ---------- */

.page-about .about-coverage {
  display: grid;
  gap: 22px;
  margin: 30px 0 26px;
  padding: 24px;
  border-radius: 24px;
  border: 1px solid var(--about-hair-soft);
  background: rgba(16, 42, 62, 0.42);
}

.page-about .about-map {
  display: block;
  width: 100%;
  max-width: 460px;
  height: auto;
}

.page-about .about-map__block {
  fill: rgba(142, 155, 166, 0.22);
  stroke: rgba(142, 155, 166, 0.5);
  stroke-width: 1.5;
  transition: fill 160ms ease;
}

.page-about .about-map__block--core {
  fill: rgba(53, 224, 200, 0.16);
  stroke: rgba(53, 224, 200, 0.65);
}

.page-about .about-map__block:hover {
  fill: rgba(53, 224, 200, 0.26);
}

.page-about .about-map__link {
  fill: none;
  stroke: rgba(199, 211, 220, 0.35);
  stroke-width: 1.2;
  stroke-dasharray: 4 5;
}

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

.page-about .about-coverage__legend li {
  display: flex;
  align-items: flex-start;
  gap: 10px;
  font-size: var(--t-note);
  line-height: 1.6;
  color: var(--about-faint);
}

.page-about .about-coverage__key {
  flex: 0 0 auto;
  width: 14px;
  height: 14px;
  margin-top: 3px;
  border-radius: 5px;
  background: rgba(142, 155, 166, 0.28);
  border: 1px solid rgba(142, 155, 166, 0.6);
}

.page-about .about-coverage__key--core {
  background: rgba(53, 224, 200, 0.22);
  border-color: rgba(53, 224, 200, 0.7);
}

/* ---------- 对接路径 ---------- */

.page-about .about-paths {
  display: grid;
  gap: 16px;
  margin-top: 6px;
}

.page-about .about-path {
  padding: 22px 22px 24px;
  border-radius: 22px;
  border: 1px solid var(--about-hair-soft);
  background: rgba(16, 42, 62, 0.5);
  transition: border-color 160ms ease, background-color 160ms ease, transform 200ms ease;
}

.page-about .about-path:hover {
  border-color: rgba(53, 224, 200, 0.38);
  background: rgba(16, 42, 62, 0.78);
  transform: translateY(-2px);
}

.page-about .about-path__tag {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--cyan);
}

.page-about .about-path p {
  max-width: 60ch;
  margin: 0 0 18px;
  font-size: 15px;
  line-height: 1.75;
  color: var(--about-faint);
}

.page-about .about-path .btn {
  margin-top: 2px;
}

/* ---------- 联络块 ---------- */

.page-about .about-contact {
  margin-top: 28px;
  padding: 24px 24px 22px;
  border-radius: 22px;
  border-left: 3px solid var(--orange);
  background: linear-gradient(120deg, rgba(255, 122, 51, 0.1), rgba(16, 42, 62, 0.5) 58%);
}

.page-about .about-contact__title {
  margin: 0 0 12px;
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--cream);
}

.page-about .about-contact__line {
  max-width: 66ch;
  margin: 0 0 8px;
  font-size: 15px;
  line-height: 1.7;
  color: var(--about-text);
}

.page-about .about-contact__line a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(53, 224, 200, 0.42);
}

.page-about .about-contact__line a:hover,
.page-about .about-contact__line a:focus-visible {
  border-bottom-color: var(--cyan);
}

.page-about .about-contact__note {
  margin: 12px 0 0;
  font-size: var(--t-note);
  line-height: 1.7;
  color: var(--rock);
}

/* ---------- 桌面栅格 ---------- */

@media (min-width: 900px) {
  .page-about .about-split {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: 48px;
    padding-right: 3.5%;
  }

  .page-about .about-aside {
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
    position: sticky;
    top: 122px;
    align-self: start;
    padding-top: 8px;
    border-top: 1px solid var(--about-hair);
  }

  .page-about .about-aside__index {
    font-size: 44px;
  }

  .page-about .about-chapter {
    margin-top: 104px;
  }

  .page-about .about-figure {
    margin-top: 46px;
  }

  .page-about .about-cover-age {
    margin-top: 46px;
  }

  .page-about .about-coverage {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr);
    align-items: center;
    gap: 32px;
    padding: 30px;
  }

  .page-about .about-paths {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
  }

  .page-about .about-contact {
    margin-top: 34px;
    padding: 28px 30px 26px;
  }
}

@media (min-width: 1100px) {
  .page-about .about-hero-media {
    margin-top: 56px;
    border-radius: 32px;
  }

  .page-about .about-figure .media {
    border-radius: 28px;
  }
}

@media (min-width: 900px) and (hover: hover) {
  .page-about .about-timeline__detail {
    max-height: 0;
    margin-top: 0;
    overflow: hidden;
    opacity: 0;
    transition: max-height 320ms ease-out, opacity 240ms ease-out, margin-top 320ms ease-out;
  }

  .page-about .about-timeline__node:hover .about-timeline__detail,
  .page-about .about-timeline__node:focus-visible .about-timeline__detail,
  .page-about .about-timeline__node:focus-within .about-timeline__detail {
    max-height: 240px;
    margin-top: 12px;
    opacity: 1;
  }
}

@media (max-width: 620px) {
  .page-about {
    padding-bottom: 72px;
  }

  .page-about .about-chapter,
  .page-about .about-chapter--last {
    margin-top: 62px;
  }

  .page-about .about-lead-stat {
    padding: 18px 18px 16px;
    border-radius: 18px;
  }

  .page-about .about-coverage {
    padding: 18px;
    border-radius: 20px;
  }

  .page-about .about-path,
  .page-about .about-contact {
    padding: 18px 18px 20px;
    border-radius: 18px;
  }

  .page-about .about-hero-media,
  .page-about .about-figure .media {
    border-radius: 20px;
  }

  .page-about .about-figure .media__caption {
    position: static;
    padding: 14px 2px 0;
    color: var(--rock);
  }

  .page-about .about-figure .media__overlay {
    display: none;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-roster__bar > span,
  .page-about .about-timeline__detail,
  .page-about .about-timeline__dot,
  .page-about .about-path,
  .page-about .about-map__block {
    transition: none;
  }
}

.page-about {
  --w: 1rem;
}