.page-about {
  --about-grid-line: rgba(18, 56, 74, 0.55);
  --about-hairline: rgba(18, 56, 74, 0.9);
  --about-mint-soft: rgba(57, 242, 192, 0.16);
  padding-bottom: clamp(1rem, 3vw, 2rem);
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  padding-block: clamp(1.5rem, 3.5vw, 2.75rem) clamp(2rem, 5vw, 3.5rem);
  border-bottom: 1px solid var(--tactical);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background-image:
    linear-gradient(to right, var(--about-grid-line) 1px, transparent 1px),
    linear-gradient(to bottom, var(--about-grid-line) 1px, transparent 1px);
  background-size: 84px 84px;
  -webkit-mask-image: radial-gradient(130% 95% at 8% 0%, #000 0%, transparent 70%);
  mask-image: radial-gradient(130% 95% at 8% 0%, #000 0%, transparent 70%);
  opacity: 0.5;
  pointer-events: none;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  top: -34%;
  right: -14%;
  width: min(520px, 68vw);
  aspect-ratio: 1 / 1;
  z-index: -1;
  background: radial-gradient(circle, rgba(57, 242, 192, 0.14), transparent 62%);
  pointer-events: none;
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(1.25rem, 4vw, 2.5rem);
}

.page-about .about-hero__eyebrow {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
  margin: 0 0 1rem;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--mist);
}

.page-about .about-hero__eyebrow span:first-child {
  color: var(--mint);
}

.page-about .about-hero__title {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(1.95rem, 5.6vw, 4rem);
  font-weight: 900;
  line-height: 1.05;
  letter-spacing: -0.02em;
  color: var(--white);
  max-width: 18ch;
}

.page-about .about-hero__aside {
  display: flex;
  flex-direction: column;
  gap: 0.9rem;
  padding-left: 1.05rem;
  border-left: 2px solid var(--orange);
}

.page-about .about-hero__quote {
  margin: 0;
  font-family: var(--font-serif);
  font-size: clamp(1rem, 2.1vw, 1.3rem);
  line-height: 1.9;
  color: var(--mist);
}

.page-about .about-hero__byline {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  color: var(--mute);
}

/* ---------- 数据条 ---------- */

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(1.75rem, 4vw, 2.75rem) 0 0;
  background: var(--tactical);
  border: 1px solid var(--tactical);
}

.page-about .about-stats__item {
  background: var(--ink);
  padding: 0.95rem 1rem 1.05rem;
  min-width: 0;
}

.page-about .about-stats__label {
  margin: 0;
  font-size: 0.75rem;
  letter-spacing: 0.07em;
  color: var(--mist);
}

.page-about .about-stats__value {
  display: flex;
  align-items: baseline;
  gap: 0.28rem;
  margin: 0.4rem 0 0;
}

.page-about .about-stats__num {
  font-family: var(--font-mono);
  font-size: clamp(1.55rem, 4.2vw, 2.15rem);
  font-weight: 700;
  line-height: 1;
  color: var(--mint);
}

.page-about .about-stats__unit {
  font-size: 0.75rem;
  color: var(--mist);
  white-space: nowrap;
}

/* ---------- 目录与正文两栏 ---------- */

.page-about .about-body {
  display: grid;
  gap: clamp(1.5rem, 4vw, 3rem);
  padding-block: clamp(2rem, 5vw, 3.75rem) 0;
}

.page-about .about-rail {
  min-width: 0;
}

.page-about .about-rail__label {
  margin: 0 0 0.55rem;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.18em;
  text-transform: uppercase;
  color: var(--mute);
}

.page-about .about-rail__list {
  display: flex;
  gap: 0.4rem;
  margin: 0;
  padding: 0 0 0.35rem;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: none;
}

.page-about .about-rail__list::-webkit-scrollbar {
  display: none;
}

.page-about .about-rail__link {
  display: inline-block;
  white-space: nowrap;
  padding: 0.45rem 0.7rem;
  font-size: 0.8125rem;
  color: var(--mist);
  text-decoration: none;
  border: 1px solid var(--tactical);
  transition: color 0.18s ease, border-color 0.18s ease;
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  color: var(--mint);
  border-color: var(--mint);
}

/* ---------- 时间线主轴 ---------- */

.page-about .about-stream {
  position: relative;
  min-width: 0;
}

.page-about .about-stream::before {
  content: "";
  position: absolute;
  left: 11px;
  top: 0.5rem;
  bottom: 0;
  width: 2px;
  background: linear-gradient(to bottom, var(--mint) 0%, rgba(57, 242, 192, 0.3) 45%, rgba(18, 56, 74, 0.18) 100%);
  pointer-events: none;
}

.page-about .about-chapter {
  position: relative;
  padding-left: 2.4rem;
  padding-bottom: clamp(2.25rem, 5vw, 3.5rem);
}

.page-about .about-chapter:last-of-type {
  padding-bottom: clamp(1rem, 3vw, 1.75rem);
}

.page-about .about-chapter::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 0.5rem;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  border: 2px solid var(--mint);
  background: var(--ink);
  box-shadow: 0 0 0 4px rgba(7, 19, 31, 0.92);
  z-index: 1;
}

.page-about .about-chapter__num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.16em;
  color: var(--mint);
}

.page-about .about-chapter__title {
  margin: 0.4rem 0 1rem;
  font-family: var(--font-display);
  font-size: clamp(1.3rem, 3.2vw, 1.95rem);
  font-weight: 800;
  line-height: 1.22;
  letter-spacing: -0.01em;
  color: var(--white);
  max-width: 24ch;
}

.page-about .about-chapter__inner {
  display: grid;
  gap: 1.4rem;
}

.page-about .about-chapter__main {
  min-width: 0;
}

/* ---------- 旁注卡 ---------- */

.page-about .about-note {
  background: var(--ink-2);
  border-left: 2px solid var(--orange);
  padding: 0.95rem 1.05rem 1.05rem;
  align-self: start;
}

.page-about .about-note__label {
  margin: 0 0 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.16em;
  color: var(--orange);
  text-transform: uppercase;
}

.page-about .about-note__text {
  margin: 0;
  font-size: 0.875rem;
  line-height: 1.78;
  color: var(--mist);
}

/* ---------- 三条路线卡 ---------- */

.page-about .about-lanes {
  display: grid;
  gap: 0.9rem;
  margin-top: 1.35rem;
}

.page-about .about-lane {
  position: relative;
  padding: 1.1rem 1.15rem 1.5rem;
  background: linear-gradient(158deg, var(--ink-2) 0%, rgba(11, 30, 48, 0.35) 100%);
  border: 1px solid var(--tactical);
  transition: border-color 0.2s ease, transform 0.2s ease;
}

.page-about .about-lane::after {
  content: "";
  position: absolute;
  right: 0;
  bottom: 0;
  width: 18px;
  height: 18px;
  background: linear-gradient(135deg, transparent 50%, var(--orange) 50%);
  pointer-events: none;
}

.page-about .about-lane:hover {
  border-color: rgba(57, 242, 192, 0.5);
}

.page-about .about-lane__idx {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  color: var(--mint);
}

.page-about .about-lane__title {
  margin: 0.4rem 0 0.5rem;
  font-family: var(--font-display);
  font-size: 1.0625rem;
  font-weight: 700;
  line-height: 1.4;
  color: var(--white);
}

.page-about .about-lane__text {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.75;
  color: var(--mist);
}

.page-about .about-lane__go {
  display: inline-block;
  margin-top: 0.8rem;
  font-size: 0.8125rem;
  color: var(--orange);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color 0.18s ease;
}

.page-about .about-lane__go:hover,
.page-about .about-lane__go:focus-visible {
  border-bottom-color: var(--orange);
}

/* ---------- 三个小组 ---------- */

.page-about .about-crews {
  display: grid;
  gap: 1px;
  margin-top: 1.3rem;
  background: var(--tactical);
  border: 1px solid var(--tactical);
}

.page-about .about-crew {
  background: var(--ink);
  padding: 1.05rem 1.1rem 1.15rem;
  min-width: 0;
}

.page-about .about-crew__name {
  margin: 0 0 0.45rem;
  font-family: var(--font-display);
  font-size: 0.9375rem;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: var(--mint);
}

.page-about .about-crew__desc {
  margin: 0;
  font-size: 0.875rem;
  line-height: 1.78;
  color: var(--mist);
}

/* ---------- 图片 ---------- */

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

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

.page-about .about-figure .media-caption {
  margin-top: 0.6rem;
  font-size: 0.75rem;
  line-height: 1.6;
  color: var(--mute);
}

/* ---------- 年份时间线 ---------- */

.page-about .about-timeline {
  list-style: none;
  margin: 1.35rem 0 0;
  padding: 0;
}

.page-about .about-timeline__row {
  display: grid;
  gap: 0.2rem;
  padding: 0.95rem 0;
  border-top: 1px solid var(--about-hairline);
}

.page-about .about-timeline__row:last-child {
  border-bottom: 1px solid var(--about-hairline);
}

.page-about .about-timeline__year {
  font-family: var(--font-mono);
  font-size: 1rem;
  letter-spacing: 0.04em;
  color: var(--mint);
}

.page-about .about-timeline__what {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.78;
  color: var(--mist);
}

.page-about .about-timeline__what strong {
  color: var(--white);
  font-weight: 600;
}

/* ---------- 标签组 ---------- */

.page-about .about-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem;
  margin-top: 1.15rem;
}

/* ---------- 收尾 ---------- */

.page-about .about-close {
  position: relative;
  overflow: hidden;
  margin-top: clamp(1rem, 3vw, 2rem);
  padding: clamp(1.5rem, 4vw, 2.5rem);
  border: 1px solid var(--tactical);
  background:
    linear-gradient(135deg, var(--about-mint-soft) 0%, transparent 46%),
    var(--ink-2);
}

.page-about .about-close__title {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(1.2rem, 3vw, 1.75rem);
  font-weight: 800;
  line-height: 1.3;
  color: var(--white);
  max-width: 22ch;
}

.page-about .about-close__text {
  margin: 0.7rem 0 0;
  font-size: 0.9rem;
  line-height: 1.78;
  color: var(--mist);
  max-width: 46ch;
}

.page-about .about-close__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.65rem;
  margin-top: 1.2rem;
}

/* ---------- 响应式 ---------- */

@media (min-width: 640px) {
  .page-about .about-timeline__row {
    grid-template-columns: 5.5rem minmax(0, 1fr);
    gap: 0.2rem 1rem;
    align-items: start;
  }

  .page-about .about-timeline__year {
    padding-top: 0.1rem;
  }
}

@media (min-width: 760px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

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

  .page-about .about-lanes > .about-lane:first-child {
    grid-column: 1 / -1;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    align-items: end;
  }

  .page-about .about-chapter__inner {
    grid-template-columns: minmax(0, 1fr) 246px;
    gap: 1.75rem;
    align-items: start;
  }

  .page-about .about-chapter__inner--single {
    grid-template-columns: minmax(0, 1fr);
  }
}

@media (min-width: 1000px) {
  .page-about .about-body {
    grid-template-columns: 196px minmax(0, 1fr);
    align-items: start;
  }

  .page-about .about-rail {
    position: sticky;
    top: 6rem;
    align-self: start;
  }

  .page-about .about-rail__list {
    flex-direction: column;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .about-rail__link {
    border: 0;
    border-left: 1px solid var(--tactical);
    padding: 0.3rem 0 0.3rem 0.8rem;
    white-space: normal;
  }

  .page-about .about-rail__link:hover,
  .page-about .about-rail__link:focus-visible {
    border-left-color: var(--mint);
  }
}

@media (min-width: 1180px) {
  .page-about .about-chapter {
    padding-left: 3rem;
  }

  .page-about .about-chapter::before {
    left: 6px;
    width: 18px;
    height: 18px;
  }

  .page-about .about-stream::before {
    left: 14px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-lane,
  .page-about .about-rail__link,
  .page-about .about-lane__go {
    transition: none;
  }
}