.page-about {
  --about-rail: 172px;
  background-color: var(--ink-900);
  color: var(--white);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
}

/* ---------- 首屏 ---------- */
.page-about .about-intro {
  position: relative;
  padding: clamp(22px, 3.6vw, 38px) 0 clamp(34px, 6vw, 74px);
  border-bottom: 1px solid var(--line);
  background:
    radial-gradient(72% 120% at 88% 0%, rgba(63, 216, 224, 0.16), transparent 62%),
    radial-gradient(54% 100% at 0% 100%, rgba(242, 180, 65, 0.1), transparent 62%),
    linear-gradient(180deg, var(--ink-850) 0%, var(--ink-900) 100%);
}

.page-about .about-intro::after {
  content: "";
  position: absolute;
  right: 0;
  bottom: 0;
  width: min(48vw, 460px);
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--cyan));
  opacity: 0.7;
}

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

.page-about .about-intro__grid {
  display: grid;
  gap: clamp(24px, 4vw, 40px);
}

.page-about .about-intro__lead .eyebrow {
  margin: 0 0 12px;
}

.page-about .about-intro h1 {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(27px, 4.4vw, 50px);
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--white);
}

.page-about .about-intro__lede {
  margin: 16px 0 0;
  max-width: 40em;
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.8;
  color: var(--muted);
}

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

.page-about .about-intro__facts li {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 10px 0 10px 14px;
  border-left: 2px solid var(--gold-line);
  background: linear-gradient(90deg, rgba(242, 180, 65, 0.07), transparent 72%);
}

.page-about .fact-k {
  flex: none;
  font-family: var(--font-mono);
  font-size: clamp(17px, 2vw, 21px);
  font-weight: 700;
  color: var(--gold);
  letter-spacing: 0.02em;
}

.page-about .fact-v {
  font-size: 13.5px;
  line-height: 1.55;
  color: var(--muted);
}

/* ---------- 通栏图 ---------- */
.page-about .about-banner {
  margin-top: 0;
  padding-top: clamp(20px, 4vw, 38px);
}

.page-about .about-banner .media-frame {
  border: 1px solid var(--line);
  box-shadow: var(--shadow-2);
}

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

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

/* ---------- 章节基座 ---------- */
.page-about .about-sec {
  padding: clamp(44px, 6.6vw, 84px) 0;
  border-top: 1px solid var(--line);
}

.page-about .about-sec > .shell {
  display: grid;
  gap: clamp(22px, 3.6vw, 40px);
}

.page-about .section__head {
  max-width: 62ch;
}

.page-about .section__no {
  font-family: var(--font-mono);
  color: var(--gold);
  letter-spacing: 0.12em;
}

.page-about .section__title {
  margin: 8px 0 0;
  font-family: var(--font-display);
  font-size: clamp(21px, 2.9vw, 33px);
  line-height: 1.18;
  letter-spacing: -0.02em;
  color: var(--white);
}

.page-about .section__lede {
  margin: 12px 0 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- 起点 ---------- */
.page-about .origin-grid {
  display: grid;
  gap: clamp(24px, 3.4vw, 40px);
}

.page-about .origin-grid .prose p {
  margin: 0 0 16px;
  max-width: 36em;
  font-size: 16px;
  line-height: 1.8;
  color: #d7e3ec;
}

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

.page-about .origin-note {
  align-self: start;
  padding: 18px 18px 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--ink-700);
  box-shadow: var(--shadow-1);
}

.page-about .origin-note__title {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.1em;
  color: var(--cyan);
}

.page-about .origin-note__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .origin-note__list li {
  padding-left: 12px;
  border-left: 1px solid var(--line);
}

.page-about .origin-note__list a {
  display: block;
  font-size: 14.5px;
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 0.15s ease;
}

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

.page-about .origin-note__list span {
  display: block;
  margin-top: 2px;
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--muted);
}

/* ---------- 流程 ---------- */
.page-about .flow-figure {
  position: relative;
}

.page-about .flow-figure .media-frame {
  border: 1px solid var(--line);
  background: var(--ink-700);
}

.page-about .flow-figure__cap {
  margin: 10px 0 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--muted);
}

.page-about .flow-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .flow-step {
  position: relative;
  padding: 18px 18px 16px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--ink-700);
  box-shadow: var(--shadow-1);
  transition: border-color 0.18s ease, transform 0.18s ease;
}

.page-about .flow-step::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 2px;
  background: linear-gradient(90deg, var(--gold), transparent 72%);
  opacity: 0.7;
}

.page-about .flow-step:hover {
  border-color: var(--gold-line);
  transform: translateY(-2px);
}

.page-about .flow-step__no {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 12.5px;
  font-weight: 700;
  letter-spacing: 0.14em;
  color: var(--gold);
}

.page-about .flow-step__title {
  margin: 6px 0 8px;
  font-family: var(--font-display);
  font-size: 17px;
  letter-spacing: -0.01em;
  color: var(--white);
}

.page-about .flow-step__text {
  margin: 0;
  font-size: 13.8px;
  line-height: 1.75;
  color: var(--muted);
}

/* ---------- 团队 ---------- */
.page-about .team-linkmap {
  margin: 0;
}

.page-about .team-linkmap svg {
  display: block;
  width: 100%;
  max-width: 720px;
  height: auto;
}

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

.page-about .team-card {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 20px 18px 18px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(170deg, var(--ink-700) 0%, var(--ink-800) 100%);
  box-shadow: var(--shadow-1);
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.page-about .team-card::after {
  content: "";
  position: absolute;
  right: 14px;
  top: 0;
  width: 46px;
  height: 2px;
  background: var(--cyan);
  opacity: 0.55;
  transition: opacity 0.2s ease, width 0.2s ease;
}

.page-about .team-card:hover,
.page-about .team-card:focus-within {
  border-color: var(--cyan-line);
  box-shadow: var(--shadow-2);
}

.page-about .team-card:hover::after,
.page-about .team-card:focus-within::after {
  opacity: 1;
  width: 84px;
}

.page-about .team-card__name {
  margin: 0;
  font-family: var(--font-display);
  font-size: 17px;
  letter-spacing: -0.01em;
  color: var(--white);
}

.page-about .team-card__role {
  margin: 0;
  flex: 1 1 auto;
  font-size: 13.8px;
  line-height: 1.75;
  color: var(--muted);
}

.page-about .team-card__link {
  align-self: flex-start;
  font-family: var(--font-mono);
  font-size: 12.5px;
  letter-spacing: 0.03em;
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid var(--cyan-line);
  padding-bottom: 2px;
}

.page-about .team-card__link:hover,
.page-about .team-card__link:focus-visible {
  color: var(--gold);
  border-bottom-color: var(--gold-line);
}

/* ---------- 里程碑 ---------- */
.page-about .mile-figure .media-frame {
  border: 1px solid var(--line);
  background: var(--ink-700);
}

.page-about .about-miles {
  display: grid;
  gap: clamp(20px, 3vw, 32px);
}

.page-about .mile-rail {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .mile-rail__link {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 7px 12px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--ink-700);
  text-decoration: none;
  transition: border-color 0.18s ease, background-color 0.18s ease;
}

.page-about .mile-rail__year {
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--muted);
  transition: color 0.18s ease;
}

.page-about .mile-rail__label {
  font-size: 12px;
  color: var(--muted);
}

.page-about .mile-rail__link:hover {
  border-color: var(--gold-line);
}

.page-about .mile-rail__link.is-active {
  border-color: var(--gold-line);
  background: var(--gold-soft);
}

.page-about .mile-rail__link.is-active .mile-rail__year {
  color: var(--gold);
}

.page-about .about-miles__doc {
  display: grid;
  gap: 0;
  min-width: 0;
}

.page-about .mile {
  position: relative;
  padding: 0 0 clamp(28px, 4vw, 48px) clamp(18px, 2.6vw, 30px);
  border-left: 1px solid var(--line);
  scroll-margin-top: 120px;
}

.page-about .mile:last-child {
  padding-bottom: 0;
  border-left-color: transparent;
}

.page-about .mile::before {
  content: "";
  position: absolute;
  left: -5px;
  top: 8px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--ink-900);
  border: 2px solid var(--cyan);
  box-shadow: 0 0 0 4px rgba(63, 216, 224, 0.1);
}

.page-about .mile:last-child::before {
  border-color: var(--gold);
  box-shadow: 0 0 0 4px rgba(242, 180, 65, 0.12);
}

.page-about .mile__year {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.14em;
  color: var(--gold);
}

.page-about .mile__title {
  margin: 8px 0 10px;
  font-family: var(--font-display);
  font-size: clamp(18px, 2.2vw, 23px);
  line-height: 1.25;
  letter-spacing: -0.02em;
  color: var(--white);
}

.page-about .mile__body p {
  margin: 0 0 12px;
  max-width: 40em;
  font-size: 14.5px;
  line-height: 1.8;
  color: #cfdde8;
}

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

/* ---------- 版本对照 ---------- */
.page-about .compare {
  display: grid;
  gap: 12px;
  margin-top: 20px;
}

.page-about .compare__col {
  padding: 16px 16px 14px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--ink-700);
}

.page-about .compare__col--old {
  border-color: var(--line);
}

.page-about .compare__col--new {
  border-color: var(--gold-line);
  background: linear-gradient(170deg, rgba(242, 180, 65, 0.07), var(--ink-700) 62%);
}

.page-about .compare__head {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--muted);
}

.page-about .compare__col--new .compare__head {
  color: var(--gold);
}

.page-about .compare__steps {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 8px;
  counter-reset: cmp;
}

.page-about .compare__steps li {
  position: relative;
  padding-left: 20px;
  font-family: var(--font-mono);
  font-size: 13px;
  line-height: 1.55;
  color: #cfdde8;
}

.page-about .compare__steps li::before {
  content: "›";
  position: absolute;
  left: 4px;
  top: 0;
  color: var(--muted);
}

.page-about .compare__col--new .compare__steps li::before {
  content: "▸";
  color: var(--gold);
}

.page-about .compare__badge {
  display: inline-block;
  margin: 14px 0 0;
  padding: 3px 10px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.page-about .compare__badge--gold {
  border-color: var(--gold-line);
  background: var(--gold-soft);
  color: var(--gold);
}

/* ---------- 选择理由 ---------- */
.page-about .why-grid {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.page-about .why-card {
  padding: 20px 18px 18px;
  border: 1px solid var(--line);
  border-top: 2px solid var(--cyan-line);
  border-radius: var(--radius);
  background: var(--ink-700);
  box-shadow: var(--shadow-1);
}

.page-about .why-card__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(22px, 3vw, 28px);
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--gold);
}

.page-about .why-card__title {
  margin: 8px 0 8px;
  font-family: var(--font-display);
  font-size: 16px;
  line-height: 1.35;
  letter-spacing: -0.01em;
  color: var(--white);
}

.page-about .why-card__text {
  margin: 0;
  font-size: 13.6px;
  line-height: 1.75;
  color: var(--muted);
}

/* ---------- 合作 ---------- */
.page-about .partner-grid {
  display: grid;
  gap: 12px;
}

.page-about .partner-card {
  padding: 18px;
  border: 1px solid var(--line);
  border-left: 2px solid var(--indigo);
  border-radius: var(--radius);
  background: var(--ink-700);
}

.page-about .partner-card__title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-size: 16px;
  letter-spacing: -0.01em;
  color: var(--white);
}

.page-about .partner-card p {
  margin: 0;
  font-size: 13.8px;
  line-height: 1.78;
  color: var(--muted);
}

.page-about .partner-contact {
  display: grid;
  gap: 18px;
  padding: clamp(20px, 3vw, 30px);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background:
    radial-gradient(90% 130% at 100% 0%, rgba(63, 216, 224, 0.12), transparent 60%),
    linear-gradient(160deg, var(--ink-700), var(--ink-850));
  box-shadow: var(--shadow-2);
}

.page-about .partner-contact__text h3 {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-size: clamp(18px, 2.2vw, 22px);
  letter-spacing: -0.02em;
  color: var(--white);
}

.page-about .partner-contact__text p {
  margin: 0;
  max-width: 42em;
  font-size: 14px;
  line-height: 1.8;
  color: var(--muted);
}

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

.page-about .partner-contact__list li {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 6px 14px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--line);
}

.page-about .partner-contact__list li:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}

.page-about .partner-contact__key {
  flex: none;
  min-width: 5.5em;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.1em;
  color: var(--gold);
}

.page-about .partner-contact__val {
  font-size: 14px;
  color: var(--white);
  word-break: break-word;
}

.page-about .partner-contact__btn {
  align-self: start;
  justify-self: start;
}

/* ---------- 断点 ---------- */
@media (min-width: 760px) {
  .page-about .flow-list {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 14px;
  }

  .page-about .team-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 16px;
  }

  .page-about .compare {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 14px;
  }

  .page-about .why-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 14px;
  }

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

@media (min-width: 900px) {
  .page-about .about-intro__grid {
    grid-template-columns: minmax(0, 1.42fr) minmax(0, 0.78fr);
    align-items: end;
    gap: clamp(32px, 5vw, 64px);
  }

  .page-about .origin-grid {
    grid-template-columns: minmax(0, 1.55fr) minmax(0, 1fr);
    align-items: start;
    gap: clamp(28px, 4vw, 52px);
  }
}

@media (min-width: 1000px) {
  .page-about .flow-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-miles {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: clamp(26px, 4vw, 56px);
    align-items: start;
  }

  .page-about .about-miles__rail {
    position: sticky;
    top: 112px;
  }

  .page-about .mile-rail {
    flex-direction: column;
    gap: 6px;
  }

  .page-about .mile-rail__link {
    justify-content: space-between;
    padding: 9px 12px;
  }
}

@media (min-width: 1180px) {
  .page-about .partner-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .partner-contact {
    grid-template-columns: minmax(0, 1.2fr) minmax(0, 1fr) auto;
    align-items: start;
    gap: clamp(22px, 3vw, 40px);
  }

  .page-about .partner-contact__btn {
    grid-column: 3;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .flow-step,
  .page-about .team-card,
  .page-about .mile-rail__link,
  .page-about .origin-note__list a {
    transition: none;
  }

  .page-about .flow-step:hover {
    transform: none;
  }
}