.page-about {
  --rail-w: 132px;
  --about-line: rgba(217, 178, 106, 0.24);
  background-color: var(--deep-navy);
  background-image:
    radial-gradient(90% 42% at 82% 0%, rgba(110, 91, 216, 0.2), transparent 62%),
    radial-gradient(70% 38% at 6% 42%, rgba(53, 208, 192, 0.07), transparent 60%);
  background-repeat: no-repeat;
  color: var(--mist);
  font-family: var(--font-body);
  padding-bottom: var(--sp-8);
}

.page-about .about-crumbs {
  padding-top: clamp(14px, 2.4vw, 26px);
  font-size: var(--fs-12);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding: clamp(24px, 4vw, 40px) 0 clamp(44px, 7vw, 92px);
  border-bottom: 1px solid var(--rule);
}

.page-about .about-hero__inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(28px, 5vw, 60px);
}

.page-about .about-hero__title {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(32px, 5.2vw, 58px);
  line-height: 1.24;
  letter-spacing: 0.02em;
  color: var(--mist);
  margin: var(--sp-4) 0 var(--sp-5);
  max-width: 20ch;
}

.page-about .about-hero__lede {
  font-size: var(--fs-17);
  line-height: 1.95;
  color: var(--silver);
  max-width: 62ch;
  margin: 0 0 var(--sp-6);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--sp-3);
}

.page-about .about-hero__panel {
  position: relative;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  padding: clamp(22px, 3vw, 36px);
  border: 1px solid var(--hairline);
  border-radius: 3px;
  background: linear-gradient(160deg, var(--glass-strong), var(--glass));
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.page-about .about-hero__panel::after {
  content: "";
  position: absolute;
  right: -38%;
  bottom: -42%;
  width: 260px;
  height: 260px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(217, 178, 106, 0.2), transparent 68%);
  pointer-events: none;
}

.page-about .about-hero__panel-tag {
  margin: 0;
  font-size: var(--fs-12);
  letter-spacing: 0.3em;
  color: var(--silver);
}

.page-about .about-hero__panel-big {
  margin: var(--sp-4) 0 var(--sp-2);
  font-size: clamp(64px, 10vw, 96px);
  line-height: 1;
  letter-spacing: -0.02em;
  color: var(--gold);
}

.page-about .about-hero__panel-sub {
  margin: 0;
  font-size: var(--fs-14);
  line-height: 1.8;
  color: var(--silver);
}

.page-about .about-hero__strip {
  display: flex;
  gap: 6px;
  margin: var(--sp-5) 0 var(--sp-4);
}

.page-about .about-hero__strip span {
  height: 3px;
  border-radius: 2px;
  background: var(--copper);
  opacity: 0.5;
}

.page-about .about-hero__strip span:nth-child(1) {
  flex: 48;
  background: var(--gold);
  opacity: 0.85;
}

.page-about .about-hero__strip span:nth-child(2) {
  flex: 36;
}

.page-about .about-hero__strip span:nth-child(3) {
  flex: 36;
}

.page-about .about-stats {
  list-style: none;
  margin: 0;
  padding: var(--sp-4) 0 0;
  border-top: 1px solid var(--rule);
  display: grid;
  gap: var(--sp-3);
}

.page-about .about-stats li {
  display: flex;
  align-items: baseline;
  gap: var(--sp-3);
}

.page-about .about-stats__num {
  min-width: 4.6em;
  font-size: var(--fs-22);
  color: var(--mist);
}

.page-about .about-stats__label {
  font-size: var(--fs-14);
  color: var(--silver);
}

/* ---------- 时间轴 ---------- */
.page-about .about-stages {
  padding-top: clamp(24px, 4vw, 48px);
}

.page-about .about-stage {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--sp-4);
  padding: clamp(32px, 5vw, 60px) 0;
  border-top: 1px solid var(--rule);
  scroll-margin-top: calc(var(--header-h) + 28px);
}

.page-about .about-stage:first-of-type {
  border-top: none;
}

.page-about .about-stage:target {
  border-top-color: var(--gold);
}

.page-about .about-stage__rail {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
}

.page-about .about-stage__num {
  font-size: var(--fs-32);
  line-height: 1;
  letter-spacing: 0.06em;
  color: var(--gold);
}

.page-about .about-stage__note {
  font-size: var(--fs-12);
  letter-spacing: 0.22em;
  color: var(--silver);
  text-transform: uppercase;
}

.page-about .about-stage__title {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: clamp(24px, 3.2vw, 40px);
  line-height: 1.34;
  letter-spacing: 0.02em;
  color: var(--mist);
  margin: 0 0 var(--sp-4);
}

.page-about .about-stage__content p {
  font-size: var(--fs-17);
  line-height: 1.95;
  color: var(--silver);
  max-width: 68ch;
  margin: 0 0 var(--sp-4);
}

.page-about .about-stage__content .about-stage__lede {
  font-family: var(--font-display);
  font-size: clamp(18px, 2.1vw, 22px);
  line-height: 1.7;
  color: var(--mist);
  margin: 0 0 var(--sp-5);
}

.page-about .about-stage__figure {
  margin: var(--sp-5) 0 var(--sp-4);
}

.page-about .about-stage__figure--wide {
  aspect-ratio: 14 / 9;
}

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

/* 可展开的补充说明 */
.page-about .about-more {
  margin-top: var(--sp-5);
  padding-top: var(--sp-3);
  border-top: 1px dashed var(--copper-line);
}

.page-about .about-more__summary {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-2);
  padding: var(--sp-2) 0;
  cursor: pointer;
  list-style: none;
  font-size: var(--fs-14);
  letter-spacing: 0.06em;
  color: var(--gold);
  transition: color 0.2s var(--ease);
}

.page-about .about-more__summary::-webkit-details-marker {
  display: none;
}

.page-about .about-more__summary::before {
  content: "＋";
  font-family: var(--font-mono);
  font-size: var(--fs-14);
  color: var(--copper);
  transition: transform 0.2s var(--ease), color 0.2s var(--ease);
}

.page-about .about-more[open] .about-more__summary::before {
  transform: rotate(45deg);
  color: var(--spark-teal);
}

.page-about .about-more__summary:hover {
  color: var(--spark-teal);
}

.page-about .about-more__summary:focus-visible {
  outline: 2px solid var(--spark-teal);
  outline-offset: 4px;
}

.page-about .about-more p {
  margin: var(--sp-3) 0 0;
  font-size: var(--fs-14);
  line-height: 1.9;
  color: var(--silver);
  max-width: 66ch;
}

/* ---------- 编号区间表 ---------- */
.page-about .about-axis {
  list-style: none;
  margin: var(--sp-5) 0 0;
  padding: 0;
  display: flex;
  flex-direction: column;
  gap: 2px;
  border: 1px solid var(--copper-line);
  border-radius: 2px;
  overflow: hidden;
}

.page-about .about-axis__seg {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: var(--sp-2) var(--sp-4);
  padding: var(--sp-4);
  background: var(--navy-mid);
  border-left: 3px solid transparent;
  transition: background-color 0.24s var(--ease);
}

.page-about .about-axis__seg:nth-child(1) {
  border-left-color: var(--gold);
}

.page-about .about-axis__seg:nth-child(2) {
  border-left-color: var(--copper);
}

.page-about .about-axis__seg:nth-child(3) {
  border-left-color: var(--night-violet);
}

.page-about .about-axis__seg:hover {
  background: var(--deep-steel);
}

.page-about .about-axis__range {
  font-size: var(--fs-17);
  letter-spacing: 0.04em;
  color: var(--mist);
}

.page-about .about-axis__name {
  font-family: var(--font-display);
  font-size: var(--fs-17);
  color: var(--gold);
}

.page-about .about-axis__count {
  margin-left: auto;
  font-size: var(--fs-14);
  color: var(--silver);
}

/* ---------- 班次表 ---------- */
.page-about .about-shifts {
  list-style: none;
  margin: var(--sp-5) 0 var(--sp-4);
  padding: 0;
  border-top: 1px solid var(--copper-line);
}

.page-about .about-shifts__row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--sp-4);
  padding: var(--sp-3) 0;
  border-bottom: 1px solid var(--rule);
}

.page-about .about-shifts__name {
  font-family: var(--font-display);
  font-size: var(--fs-17);
  color: var(--mist);
}

.page-about .about-shifts__time {
  font-size: var(--fs-14);
  letter-spacing: 0.04em;
  color: var(--gold);
}

/* ---------- 团队卡 ---------- */
.page-about .about-teams {
  list-style: none;
  margin: var(--sp-5) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--sp-3);
}

.page-about .about-teams__item {
  padding: var(--sp-5);
  border-radius: 3px;
  transition: transform 0.24s var(--ease), background-color 0.24s var(--ease), border-color 0.24s var(--ease);
}

.page-about .about-teams__item:hover,
.page-about .about-teams__item:focus-within {
  transform: translateY(-4px);
  background: var(--glass-strong);
  border-color: var(--hairline);
}

.page-about .about-teams__num {
  display: block;
  margin-bottom: var(--sp-2);
  font-size: var(--fs-32);
  line-height: 1;
  color: var(--gold);
}

.page-about .about-teams__name {
  margin: 0 0 var(--sp-2);
  font-family: var(--font-display);
  font-size: var(--fs-17);
  font-weight: 600;
  color: var(--mist);
}

.page-about .about-teams__desc {
  margin: 0;
  font-size: var(--fs-14);
  line-height: 1.85;
  color: var(--silver);
}

/* ---------- 批次号 ---------- */
.page-about .about-batch {
  display: flex;
  flex-direction: column;
  gap: var(--sp-2);
  margin: var(--sp-5) 0 0;
  padding: var(--sp-5) clamp(18px, 3vw, 34px);
  border: 1px solid var(--copper-line);
  border-radius: 2px;
  background:
    linear-gradient(120deg, rgba(200, 69, 47, 0.12), transparent 58%),
    var(--navy-mid);
}

.page-about .about-batch__label {
  font-size: var(--fs-12);
  letter-spacing: 0.3em;
  color: var(--silver);
}

.page-about .about-batch__num {
  font-size: clamp(56px, 11vw, 110px);
  line-height: 0.95;
  letter-spacing: -0.02em;
  color: var(--cinnabar);
}

/* ---------- 合作方向 ---------- */
.page-about .about-tracks {
  list-style: none;
  margin: var(--sp-5) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--sp-3);
}

.page-about .about-tracks__item {
  padding: var(--sp-4) var(--sp-4) var(--sp-4);
  border: 1px solid var(--rule);
  border-left: 2px solid var(--copper-line);
  border-radius: 2px;
  background: var(--glass);
  transition: border-color 0.24s var(--ease), background-color 0.24s var(--ease);
}

.page-about .about-tracks__item:hover {
  border-left-color: var(--gold);
  background: var(--glass-strong);
}

.page-about .about-tracks__name {
  margin: 0 0 var(--sp-2);
  font-family: var(--font-display);
  font-size: var(--fs-17);
  font-weight: 600;
  color: var(--mist);
}

.page-about .about-tracks__desc {
  margin: 0;
  font-size: var(--fs-14);
  line-height: 1.8;
  color: var(--silver);
}

/* ---------- 收束区 ---------- */
.page-about .about-stage--next {
  border-top-color: var(--copper-line);
}

.page-about .about-next {
  list-style: none;
  margin: var(--sp-5) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: var(--sp-3);
}

.page-about .about-next__link {
  display: flex;
  flex-direction: column;
  gap: var(--sp-2);
  height: 100%;
  padding: var(--sp-5);
  border: 1px solid var(--rule);
  border-radius: 3px;
  background: var(--glass);
  text-decoration: none;
  transition: transform 0.24s var(--ease), background-color 0.24s var(--ease), border-color 0.24s var(--ease);
}

.page-about .about-next__link:hover,
.page-about .about-next__link:focus-visible {
  transform: translateY(-4px);
  background: var(--glass-strong);
  border-color: var(--hairline);
}

.page-about .about-next__link:focus-visible {
  outline: 2px solid var(--spark-teal);
  outline-offset: 3px;
}

.page-about .about-next__kicker {
  font-size: var(--fs-12);
  letter-spacing: 0.24em;
  color: var(--copper);
}

.page-about .about-next__title {
  font-family: var(--font-display);
  font-size: var(--fs-22);
  font-weight: 600;
  color: var(--gold);
}

.page-about .about-next__desc {
  font-size: var(--fs-14);
  line-height: 1.85;
  color: var(--silver);
}

.page-about .about-next__foot {
  margin: var(--sp-5) 0 0;
  font-size: var(--fs-14);
  line-height: 1.9;
  color: var(--silver);
  max-width: 64ch;
}

/* ---------- 桌面端 ---------- */
@media (min-width: 720px) {
  .page-about .about-axis {
    flex-direction: row;
  }

  .page-about .about-axis__seg {
    flex-direction: column;
    align-items: flex-start;
    border-left: none;
    border-top: 3px solid transparent;
  }

  .page-about .about-axis__seg:nth-child(1) {
    flex: 48;
    border-top-color: var(--gold);
  }

  .page-about .about-axis__seg:nth-child(2) {
    flex: 36;
    border-top-color: var(--copper);
  }

  .page-about .about-axis__seg:nth-child(3) {
    flex: 36;
    border-top-color: var(--night-violet);
  }

  .page-about .about-axis__count {
    margin-left: 0;
    margin-top: auto;
  }

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

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

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

  .page-about .about-stage {
    grid-template-columns: var(--rail-w) minmax(0, 1fr);
    gap: clamp(28px, 4vw, 64px);
    align-items: start;
  }

  .page-about .about-stage__rail {
    position: sticky;
    top: calc(var(--header-h) + 32px);
    flex-direction: column;
    align-items: flex-start;
    gap: var(--sp-4);
    padding-top: var(--sp-2);
  }

  .page-about .about-stage__num {
    font-size: clamp(44px, 4.4vw, 66px);
  }

  .page-about .about-stage__note {
    writing-mode: vertical-rl;
    letter-spacing: 0.34em;
  }

  .page-about .about-tracks {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@supports (-webkit-text-stroke: 1px gold) {
  @media (min-width: 900px) {
    .page-about .about-stage__num {
      color: transparent;
      -webkit-text-stroke: 1px var(--gold);
    }

    .page-about .about-stage:target .about-stage__num {
      color: var(--gold);
      -webkit-text-stroke: 0;
    }
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about * {
    transition-duration: 0.01ms !important;
    animation-duration: 0.01ms !important;
  }
}