.page-about {
  --about-line: rgba(143, 166, 163, 0.28);
  --about-line-soft: rgba(143, 166, 163, 0.14);
  --about-rail: 1fr;
  background: var(--night);
  color: var(--paper);
  overflow-x: hidden;
}

.page-about .about-crumb {
  padding-top: 18px;
}

.page-about .breadcrumb {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--mist);
}

.page-about .breadcrumb a {
  color: var(--mist);
  text-decoration: none;
}

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

.page-about .breadcrumb span:last-child {
  color: var(--paper);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: clamp(28px, 5vw, 56px) 0 clamp(44px, 7vw, 92px);
  background:
    radial-gradient(110% 85% at 92% 0%, rgba(41, 231, 206, 0.14), transparent 58%),
    linear-gradient(180deg, var(--green) 0%, var(--night) 74%);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(to right, var(--grid) 1px, transparent 1px),
    linear-gradient(to bottom, var(--grid) 1px, transparent 1px);
  background-size: 8px 8px;
  opacity: 0.6;
  mask-image: linear-gradient(180deg, rgba(0, 0, 0, 0.9), transparent 88%);
}

.page-about .about-hero__grid {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(28px, 4vw, 48px);
}

.page-about .about-hero__kicker {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--cyan);
}

.page-about .about-hero__title {
  margin: 0 0 20px;
  font-family: var(--font-display);
  font-weight: 900;
  letter-spacing: -0.02em;
  line-height: 1.12;
  font-size: clamp(32px, 7vw, 60px);
}

.page-about .about-hero__lede {
  max-width: 46ch;
  color: var(--paper);
  opacity: 0.88;
}

.page-about .about-hero__stats {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--about-line);
  border: 1px solid var(--about-line);
}

.page-about .about-hero__stats li {
  background: var(--night-deep);
  padding: 16px 14px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.page-about .about-hero__num {
  font-family: var(--font-mono);
  font-size: clamp(26px, 4vw, 36px);
  line-height: 1;
  color: var(--cyan);
  font-variant-numeric: tabular-nums;
}

.page-about .about-hero__num.num--gold {
  color: var(--gold);
}

.page-about .about-hero__unit {
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--mist);
}

/* ---------- 长卷章节 ---------- */
.page-about .about-body {
  padding-bottom: clamp(48px, 8vw, 96px);
}

.page-about .chapter-block {
  position: relative;
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  padding: clamp(40px, 6vw, 84px) 0;
  border-top: 1px solid var(--about-line);
}

.page-about .chapter-block__rail {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding-bottom: 4px;
}

.page-about .chapter-block__tag {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--mist);
}

.page-about .chapter-block__body {
  min-width: 0;
}

.page-about .chapter-block__body > p {
  max-width: 42ch;
  line-height: 1.8;
  color: var(--paper);
  opacity: 0.86;
  margin: 0 0 16px;
}

.page-about .chapter__title {
  margin: 0 0 18px;
  font-family: var(--font-display);
  font-weight: 700;
  letter-spacing: -0.01em;
  line-height: 1.2;
  font-size: clamp(24px, 4vw, 38px);
}

.page-about .about-quote {
  max-width: 30ch;
  margin: 0 0 24px;
  padding-left: 16px;
  border-left: 3px solid var(--orange);
  font-family: var(--font-display);
  font-weight: 900;
  letter-spacing: -0.01em;
  line-height: 1.35;
  font-size: clamp(22px, 3.6vw, 34px);
  color: var(--paper);
}

/* ---------- 图像 ---------- */
.page-about .about-figure {
  margin: 0 0 26px;
}

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

/* ---------- 班底图例 ---------- */
.page-about .crew {
  list-style: none;
  margin: 0 0 24px;
  padding: 0;
}

.page-about .crew__row {
  display: grid;
  grid-template-columns: 4px minmax(0, 1fr);
  gap: 16px;
  padding: 18px 0;
  border-top: 1px solid var(--about-line-soft);
}

.page-about .crew__row:last-child {
  border-bottom: 1px solid var(--about-line-soft);
}

.page-about .crew__bar {
  border-radius: 0;
  background: var(--mist);
}

.page-about .crew__row--cyan .crew__bar {
  background: var(--cyan);
}

.page-about .crew__row--gold .crew__bar {
  background: var(--gold);
}

.page-about .crew__row--orange .crew__bar {
  background: var(--orange);
}

.page-about .crew__head {
  margin: 0 0 8px;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 12px;
}

.page-about .crew__label {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 18px;
}

.page-about .crew__count {
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--mist);
}

.page-about .crew__desc {
  margin: 0;
  max-width: 44ch;
  line-height: 1.8;
  color: var(--paper);
  opacity: 0.8;
  font-size: 15px;
}

/* ---------- 标签页 ---------- */
.page-about .tabs {
  margin-top: 8px;
}

.page-about .tabs__list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 20px;
}

.page-about .tabs__btn {
  appearance: none;
  cursor: pointer;
  border: 1px solid var(--about-line);
  background: transparent;
  color: var(--paper);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 14px;
  letter-spacing: 0.02em;
  padding: 10px 18px;
  transition: background 120ms ease, color 120ms ease, border-color 120ms ease;
}

.page-about .tabs__btn:hover {
  border-color: var(--cyan);
  color: var(--cyan);
}

.page-about .tabs__btn[aria-selected="true"] {
  background: var(--orange);
  border-color: var(--orange);
  color: var(--night-deep);
}

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

.page-about .tabs__panels {
  border: 1px solid var(--about-line);
  background: linear-gradient(180deg, rgba(11, 42, 38, 0.72), rgba(10, 21, 36, 0.4));
  padding: clamp(18px, 3vw, 30px);
  min-height: 260px;
}

.page-about .tabs__lead {
  margin: 0 0 16px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 18px;
  color: var(--paper);
}

.page-about .tabs__listbody {
  list-style: none;
  margin: 0 0 16px;
  padding: 0;
}

.page-about .tabs__listbody li {
  position: relative;
  padding: 8px 0 8px 20px;
  line-height: 1.75;
  font-size: 15px;
  color: var(--paper);
  opacity: 0.86;
  border-bottom: 1px solid var(--about-line-soft);
}

.page-about .tabs__listbody li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 18px;
  width: 8px;
  height: 1px;
  background: var(--cyan);
}

.page-about .tabs__listbody strong {
  color: var(--cyan);
  font-weight: 700;
}

.page-about .tabs__panel > p:last-child {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--mist);
}

/* ---------- 赛季时间轴 ---------- */
.page-about .season-axis {
  list-style: none;
  margin: 8px 0 0;
  padding: 0 0 0 34px;
  position: relative;
  display: grid;
  gap: clamp(26px, 4vw, 42px);
}

.page-about .season-axis::before {
  content: "";
  position: absolute;
  left: 8px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: linear-gradient(180deg, var(--gold), var(--cyan) 46%, rgba(143, 166, 163, 0.18));
}

.page-about .season-axis__item {
  position: relative;
}

.page-about .season-axis__dot {
  position: absolute;
  left: -32px;
  top: 6px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--gold);
  box-shadow: 0 0 0 4px rgba(232, 180, 87, 0.16);
  transition: background 320ms ease, box-shadow 320ms ease;
}

.page-about .season-axis__item.is-visible .season-axis__dot {
  background: var(--cyan);
  box-shadow: 0 0 0 4px rgba(41, 231, 206, 0.18);
}

.page-about .season-axis__phase {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--mist);
}

.page-about .season-axis__title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 20px;
  color: var(--paper);
}

.page-about .season-axis__item > p:last-child {
  margin: 0;
  max-width: 44ch;
  line-height: 1.8;
  font-size: 15px;
  color: var(--paper);
  opacity: 0.82;
}

/* ---------- 数据流程 ---------- */
.page-about .flow {
  display: grid;
  gap: 1px;
  background: var(--about-line-soft);
  border: 1px solid var(--about-line-soft);
  margin: 8px 0 20px;
}

.page-about .flow__step {
  background: var(--night-deep);
  padding: 20px 18px;
}

.page-about .flow__no {
  display: block;
  margin-bottom: 10px;
  font-size: 13px;
  letter-spacing: 0.16em;
  color: var(--cyan);
}

.page-about .flow__title {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 17px;
}

.page-about .flow__step p {
  margin: 0;
  line-height: 1.75;
  font-size: 14px;
  color: var(--paper);
  opacity: 0.78;
}

/* ---------- 移动端升级 ---------- */
.page-about .upgrades {
  display: grid;
  gap: 18px;
  margin: 8px 0 20px;
}

.page-about .upgrade {
  padding: 20px 18px 22px;
  border-left: 4px solid var(--wine);
  background: linear-gradient(90deg, rgba(124, 31, 53, 0.28), rgba(10, 21, 36, 0.2) 70%);
}

.page-about .upgrade--indigo {
  border-left-color: var(--indigo);
  background: linear-gradient(90deg, rgba(58, 44, 110, 0.4), rgba(10, 21, 36, 0.2) 70%);
}

.page-about .upgrade__round {
  margin: 0 0 8px;
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--gold);
}

.page-about .upgrade__title {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 20px;
}

.page-about .upgrade p:last-child {
  margin: 0;
  max-width: 44ch;
  line-height: 1.8;
  font-size: 15px;
  color: var(--paper);
  opacity: 0.84;
}

/* ---------- 观察原则 ---------- */
.page-about .principles {
  display: grid;
  gap: clamp(24px, 4vw, 40px);
  grid-template-columns: 1fr;
}

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

.page-about .principles__item {
  padding: 18px 0;
  border-top: 1px solid var(--about-line-soft);
}

.page-about .principles__item:last-child {
  border-bottom: 1px solid var(--about-line-soft);
}

.page-about .principles__no {
  display: block;
  margin-bottom: 10px;
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--cyan);
}

.page-about .principles__item p {
  margin: 0;
  max-width: 42ch;
  line-height: 1.8;
  color: var(--paper);
  opacity: 0.86;
}

.page-about .principles__figure {
  margin: 0;
}

/* ---------- 结尾动作 ---------- */
.page-about .about-cta {
  margin-top: clamp(40px, 6vw, 72px);
  padding: clamp(28px, 4vw, 48px) 0 clamp(8px, 2vw, 16px);
  border-top: 1px solid var(--cyan);
}

.page-about .about-cta__title {
  margin: 0 0 14px;
  font-family: var(--font-display);
  font-weight: 900;
  letter-spacing: -0.01em;
  font-size: clamp(24px, 4vw, 36px);
}

.page-about .about-cta__text {
  margin: 0 0 22px;
  max-width: 46ch;
  line-height: 1.8;
  color: var(--paper);
  opacity: 0.84;
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.page-about .btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 12px 22px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 15px;
  text-decoration: none;
  border: 1px solid var(--mist);
  color: var(--paper);
  background: transparent;
  transition: background 120ms ease, color 120ms ease, border-color 120ms ease;
}

.page-about .btn--primary {
  background: var(--orange);
  border-color: var(--orange);
  color: var(--night-deep);
}

.page-about .btn--primary:hover {
  background: var(--gold);
  border-color: var(--gold);
}

.page-about .btn--ghost:hover {
  border-color: var(--cyan);
  color: var(--cyan);
}

.page-about .btn:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 3px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .about-hero__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

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

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.35fr) minmax(280px, 0.65fr);
    align-items: end;
  }

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

  .page-about .chapter-block {
    grid-template-columns: 132px minmax(0, 1fr);
    gap: clamp(24px, 4vw, 56px);
  }

  .page-about .chapter-block__rail {
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
    position: relative;
    padding-right: 12px;
  }

  .page-about .chapter-block__rail::after {
    content: "";
    position: absolute;
    right: 0;
    top: 4px;
    bottom: 4px;
    width: 1px;
    background: linear-gradient(180deg, var(--about-line), transparent);
  }

  .page-about .principles {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 0.6fr);
    align-items: start;
  }

  .page-about .chapter-block__body > p,
  .page-about .about-hero__lede {
    font-size: 16px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .season-axis__dot,
  .page-about .btn,
  .page-about .tabs__btn {
    transition: none;
  }
}