.page-about {
  --about-gap: clamp(1.25rem, 4vw, 2.5rem);
  --about-paper-ink: #23293a;
  --about-paper-soft: #4a5368;
  --about-cut: 18px;
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  position: relative;
  padding: clamp(2rem, 5.5vw, 4rem) 0 clamp(2.25rem, 6vw, 4.5rem);
  border-bottom: 1px solid var(--hairline-soft);
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -30%;
  right: -12%;
  width: min(720px, 78vw);
  height: min(720px, 78vw);
  background: radial-gradient(circle at 55% 45%, rgba(53, 242, 214, 0.15), transparent 62%);
  pointer-events: none;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: min(340px, 60vw);
  height: 2px;
  background: linear-gradient(90deg, var(--ember-500), transparent);
}

.page-about .about-hero__inner {
  position: relative;
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(1.75rem, 5vw, 3rem);
  align-items: end;
}

.page-about .about-hero__lead {
  max-width: 46rem;
}

.page-about .about-hero h1 {
  font-family: var(--font-display);
  font-size: clamp(2rem, 5.6vw, 4.25rem);
  line-height: 1.04;
  letter-spacing: -0.012em;
  color: var(--white);
  margin: 0 0 1.15rem;
  text-wrap: balance;
}

.page-about .about-hero__intro {
  max-width: 60ch;
  margin: 0 0 1.75rem;
  font-size: clamp(1rem, 1.3vw, 1.0625rem);
  line-height: 1.85;
  color: var(--text-dim);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.page-about .about-hero__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--hairline-soft);
  border: 1px solid var(--hairline-soft);
  clip-path: polygon(0 0, calc(100% - var(--about-cut)) 0, 100% var(--about-cut), 100% 100%, 0 100%);
}

.page-about .about-fact {
  display: flex;
  flex-direction: column;
  gap: 0.3rem;
  padding: 1.1rem 1rem 1.15rem;
  background: var(--navy-800);
}

.page-about .about-fact__label {
  font-size: 0.8125rem;
  line-height: 1.5;
  color: var(--text-dim);
}

/* ---------- 通用小件 ---------- */

.page-about .about-h2 {
  font-family: var(--font-display);
  font-size: clamp(1.5rem, 3.5vw, 2.5rem);
  line-height: 1.16;
  letter-spacing: -0.008em;
  color: var(--white);
  margin: 0 0 1rem;
  text-wrap: balance;
}

.page-about .media-frame {
  position: relative;
  overflow: hidden;
  background: var(--navy-800);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--about-cut)), calc(100% - var(--about-cut)) 100%, 0 100%);
}

.page-about .media-frame img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  object-fit: cover;
  filter: saturate(0.9) contrast(1.04);
}

.page-about .media-frame__cap {
  display: block;
  padding: 0.75rem 1rem 0.85rem;
  font-size: 0.8125rem;
  line-height: 1.6;
  color: var(--text-dim);
  border-top: 1px solid var(--hairline-soft);
}

/* ---------- 01 入口定位 ---------- */

.page-about .about-split {
  display: grid;
  grid-template-columns: 1fr;
  gap: var(--about-gap);
}

.page-about .about-split__aside {
  display: flex;
  align-items: baseline;
  gap: 0.85rem;
  padding-top: 0.75rem;
  border-top: 2px solid var(--cyan-400);
}

.page-about .about-split__idx {
  margin: 0;
  font-size: 2rem;
  line-height: 1;
  color: var(--cyan-400);
}

.page-about .about-split__kicker {
  margin: 0;
  font-size: 0.8125rem;
  letter-spacing: 0.14em;
  color: var(--text-dim);
}

.page-about .about-lines {
  list-style: none;
  margin: 1.75rem 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--hairline-soft);
  border-top: 1px solid var(--hairline-soft);
}

.page-about .about-lines li {
  display: grid;
  grid-template-columns: 1fr;
  gap: 0.3rem;
  padding: 0.95rem 0;
  background: var(--ink-950);
}

.page-about .about-lines__k {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.08em;
  color: var(--cyan-400);
}

.page-about .about-lines__v {
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--text-dim);
}

/* ---------- 02 数据链路 ---------- */

.page-about .about-pipeline__figure {
  margin: 0 0 clamp(1.75rem, 4vw, 2.75rem);
}

.page-about .about-steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}

.page-about .about-step {
  position: relative;
  padding: 1.4rem 1.15rem 1.45rem;
  background: var(--navy-800);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--about-cut)), calc(100% - var(--about-cut)) 100%, 0 100%);
}

.page-about .about-step::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--cyan-400), rgba(53, 242, 214, 0));
}

.page-about .about-step__idx {
  margin: 0 0 0.65rem;
  font-size: 0.6875rem;
  letter-spacing: 0.14em;
  color: var(--cyan-400);
}

.page-about .about-step__title {
  margin: 0 0 0.5rem;
  font-family: var(--font-display);
  font-size: 1.25rem;
  letter-spacing: 0.015em;
  color: var(--white);
}

.page-about .about-step p:last-child {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.72;
  color: var(--text-dim);
}

/* ---------- 03 版本轴线 ---------- */

.page-about .about-axis {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-axis__item {
  display: grid;
  grid-template-columns: 2.25rem minmax(0, 1fr);
  gap: clamp(0.75rem, 2.5vw, 1.5rem);
  padding-bottom: clamp(1.25rem, 3.5vw, 2rem);
}

.page-about .about-axis__rail {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.5rem;
  padding-top: 0.3rem;
}

.page-about .about-axis__item:not(:last-child) .about-axis__rail::after {
  content: "";
  position: absolute;
  top: 1.6rem;
  bottom: -1.1rem;
  left: 50%;
  width: 2px;
  transform: translateX(-50%);
  background: linear-gradient(180deg, var(--cyan-400), rgba(53, 242, 214, 0.05));
  opacity: 0.55;
}

.page-about .about-axis__dot {
  flex: none;
  width: 0.75rem;
  height: 0.75rem;
  margin-top: 0.35rem;
  border-radius: 50%;
  background: var(--cyan-400);
  box-shadow: 0 0 0 4px rgba(53, 242, 214, 0.14);
}

.page-about .about-axis__ver {
  font-size: 0.6875rem;
  letter-spacing: 0.1em;
  color: var(--text-dim);
}

.page-about .about-axis__body {
  padding: 1.15rem 1.25rem 1.3rem;
  background: var(--navy-800);
  clip-path: polygon(0 var(--about-cut), var(--about-cut) 0, 100% 0, 100% 100%, 0 100%);
}

.page-about .about-axis__body h3 {
  margin: 0 0 0.55rem;
  font-family: var(--font-display);
  font-size: clamp(1.05rem, 2vw, 1.3rem);
  line-height: 1.3;
  color: var(--white);
}

.page-about .about-axis__body p {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.78;
  color: var(--text-dim);
}

.page-about .about-versions__figure {
  margin: clamp(1.25rem, 3.5vw, 2rem) 0 0;
}

/* ---------- 04 联赛目录地图 ---------- */

.page-about .about-map {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--hairline-soft);
  border: 1px solid var(--hairline-soft);
}

.page-about .about-map__cell {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  padding: clamp(1rem, 2.5vw, 1.5rem) clamp(0.9rem, 2vw, 1.15rem);
  background: var(--ink-950);
  transition: background var(--t-fast);
}

.page-about .about-map__cell:hover,
.page-about .about-map__cell:focus-within {
  background: var(--navy-700);
}

.page-about .about-map__idx {
  margin: 0;
  font-size: 1.5rem;
  line-height: 1;
  letter-spacing: 0.05em;
  color: var(--cyan-400);
}

.page-about .about-map__name {
  margin: 0;
  font-family: var(--font-display);
  font-size: 1.0625rem;
  line-height: 1.3;
  color: var(--white);
}

.page-about .about-map__desc {
  margin: 0;
  font-size: 0.875rem;
  line-height: 1.68;
  color: var(--text-dim);
}

.page-about .about-note {
  margin: 1.35rem 0 0;
  padding-left: 0.9rem;
  border-left: 2px solid var(--ember-500);
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--text-dim);
}

/* ---------- 05 团队 ---------- */

.page-about .about-team__views {
  margin: 0 0 1.5rem;
}

.page-about .about-team__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1rem;
}

.page-about .about-team__card {
  padding: 1.3rem 1.15rem 1.4rem;
  background: var(--navy-800);
  border-left: 3px solid var(--cyan-700);
  clip-path: polygon(0 0, 100% 0, 100% 100%, var(--about-cut) 100%, 0 calc(100% - var(--about-cut)));
}

.page-about .about-team__card[hidden] {
  display: none;
}

.page-about .about-team__num {
  margin: 0 0 0.6rem;
  font-size: 2rem;
  line-height: 1;
  color: var(--cyan-400);
}

.page-about .about-team__name {
  margin: 0 0 0.55rem;
  font-family: var(--font-display);
  font-size: 1.125rem;
  line-height: 1.35;
  color: var(--white);
}

.page-about .about-team__desc {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--text-dim);
}

/* ---------- 06 备案与访问链路（纸面区） ---------- */

.page-about .about-legacy {
  position: relative;
  margin-top: clamp(2.5rem, 6vw, 4.5rem);
  padding: clamp(2rem, 5.5vw, 4rem) 0 clamp(2.25rem, 6vw, 4.5rem);
  background:
    repeating-linear-gradient(0deg, rgba(216, 207, 190, 0.28) 0 1px, transparent 1px 6px),
    var(--paper-100);
  border-top: 3px solid var(--cyan-400);
  color: var(--about-paper-ink);
}

.page-about .about-legacy__inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(1.75rem, 4.5vw, 3rem);
  align-items: start;
}

.page-about .about-legacy__eyebrow {
  color: var(--cyan-700);
}

.page-about .about-legacy__text h2 {
  margin: 0 0 1rem;
  font-family: var(--font-serif);
  font-size: clamp(1.5rem, 3.4vw, 2.25rem);
  line-height: 1.22;
  color: var(--about-paper-ink);
  text-wrap: balance;
}

.page-about .about-legacy__text p {
  margin: 0 0 1rem;
  font-size: 1rem;
  line-height: 1.88;
  color: var(--about-paper-soft);
}

.page-about .about-legacy__text a {
  color: var(--cyan-700);
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .about-legacy__text a:hover,
.page-about .about-legacy__text a:focus-visible {
  color: var(--ember-500);
}

.page-about .about-legacy__icp {
  display: inline-block;
  margin: 0.5rem 0 0;
  padding: 0.5rem 0.95rem;
  border: 1px solid var(--cyan-700);
  font-size: 0.8125rem;
  letter-spacing: 0.06em;
  color: var(--cyan-700);
  transform: rotate(-1deg);
}

.page-about .about-legacy__figure {
  margin: 0;
  clip-path: polygon(0 0, 100% 0, 100% 100%, var(--about-cut) 100%, 0 calc(100% - var(--about-cut)));
}

.page-about .about-legacy__figure .media-frame__cap {
  background: rgba(243, 237, 226, 0.86);
  color: var(--about-paper-soft);
  border-top-color: rgba(216, 207, 190, 0.9);
}

/* ---------- 响应式 ---------- */

@media (min-width: 620px) {
  .page-about .about-lines li {
    grid-template-columns: 7.5rem minmax(0, 1fr);
    gap: 1.25rem;
    align-items: baseline;
  }
}

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

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

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

@media (min-width: 880px) {
  .page-about .about-hero__inner {
    grid-template-columns: minmax(0, 1.55fr) minmax(0, 1fr);
  }

  .page-about .about-split {
    grid-template-columns: minmax(110px, 1fr) minmax(0, 2.4fr);
  }

  .page-about .about-split__aside {
    position: sticky;
    top: 6.5rem;
    flex-direction: column;
    align-items: flex-start;
    align-self: start;
  }
}

@media (min-width: 900px) {
  .page-about .about-legacy__inner {
    grid-template-columns: minmax(0, 2.4fr) minmax(0, 1fr);
    align-items: center;
  }
}

@media (min-width: 1000px) {
  .page-about .about-map {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }

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

@media (min-width: 1080px) {
  .page-about .about-steps {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 0.75rem;
    margin-bottom: 4.25rem;
  }

  .page-about .about-step:nth-child(2) {
    margin-top: 1.25rem;
  }

  .page-about .about-step:nth-child(3) {
    margin-top: 2.5rem;
  }

  .page-about .about-step:nth-child(4) {
    margin-top: 3.75rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-map__cell,
  .page-about .about-legacy__icp {
    transition: none;
    transform: none;
  }
}