.page-about {
  --about-cut: 18px;
  --about-card-bg: linear-gradient(158deg, var(--mbx-panel-2), var(--mbx-panel));
  position: relative;
  background: var(--mbx-ink);
  color: var(--mbx-fog);
  font-family: var(--mbx-font-body);
  padding-bottom: clamp(48px, 7vw, 96px);
}

.page-about *,
.page-about *::before,
.page-about *::after {
  box-sizing: border-box;
}

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

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

.page-about .about-crumb {
  padding-top: clamp(88px, 11vw, 112px);
  padding-bottom: 10px;
}

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

.page-about .about-crumb .mbx-breadcrumb a:hover {
  color: var(--mbx-cyan);
}

/* ---------- 封面 ---------- */

.page-about .about-cover {
  position: relative;
  padding: clamp(18px, 3vw, 36px) 0 clamp(36px, 6vw, 72px);
  isolation: isolate;
}

.page-about .about-cover::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  background:
    radial-gradient(120% 90% at 82% 4%, rgba(122, 14, 30, 0.62), transparent 62%),
    radial-gradient(90% 80% at 4% 100%, rgba(53, 224, 224, 0.1), transparent 66%);
  pointer-events: none;
}

.page-about .about-cover__lines {
  position: absolute;
  right: -12%;
  bottom: -18%;
  width: min(620px, 78%);
  height: auto;
  opacity: 0.22;
  z-index: -1;
  pointer-events: none;
}

.page-about .about-cover__grid {
  display: grid;
  gap: clamp(24px, 4vw, 44px);
  align-items: end;
}

.page-about .about-cover__title {
  margin: 14px 0 0;
  font-family: var(--mbx-font-body);
  font-weight: 300;
  font-size: clamp(34px, 7.6vw, 78px);
  line-height: 1.02;
  letter-spacing: -0.035em;
  color: var(--mbx-fog);
}

.page-about .about-cover__title em {
  font-style: normal;
  font-weight: 800;
  color: var(--mbx-amber);
}

.page-about .about-cover__lead {
  margin: clamp(16px, 2vw, 24px) 0 0;
  color: var(--mbx-mute);
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.85;
  max-width: 58ch;
}

.page-about .about-cover__facts {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 28px;
  margin: clamp(22px, 3vw, 34px) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-cover__fact {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding-left: 14px;
  border-left: 2px solid var(--mbx-crimson);
}

.page-about .about-cover__num {
  font-family: var(--mbx-font-display);
  font-size: clamp(20px, 2.4vw, 26px);
  line-height: 1.1;
  color: var(--mbx-fog);
  letter-spacing: -0.01em;
}

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

.page-about .about-cover__figure {
  margin: 0;
  position: relative;
}

.page-about .about-cover__figure img {
  width: 100%;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 34px), calc(100% - 34px) 100%, 0 100%);
}

.page-about .about-cover__cap {
  margin-top: 10px;
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--mbx-mute);
}

/* ---------- 主体布局与时间索引 ---------- */

.page-about .about-body {
  display: grid;
  gap: clamp(22px, 4vw, 40px);
  padding-top: clamp(16px, 3vw, 32px);
}

.page-about .about-rail__label {
  margin: 0 0 12px;
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--mbx-mute);
}

.page-about .about-rail__list {
  display: flex;
  gap: 10px;
  margin: 0;
  padding: 0 0 10px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .about-rail__item {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 9px 16px;
  border: 1px solid var(--mbx-line);
  border-radius: 999px;
  color: var(--mbx-mute);
  text-decoration: none;
  white-space: nowrap;
  transition: color 200ms var(--mbx-ease), border-color 200ms var(--mbx-ease), background 200ms var(--mbx-ease);
}

.page-about .about-rail__item:hover,
.page-about .about-rail__item:focus-visible {
  color: var(--mbx-fog);
  border-color: var(--mbx-cyan);
  background: rgba(53, 224, 224, 0.08);
}

.page-about .about-rail__num {
  font-size: 11px;
  letter-spacing: 0.08em;
  color: var(--mbx-amber);
}

.page-about .about-rail__name {
  font-size: 14px;
  font-weight: 600;
  color: inherit;
}

.page-about .about-rail__hint {
  display: none;
}

/* ---------- 章节通用 ---------- */

.page-about .about-sec + .about-sec {
  margin-top: clamp(52px, 8vw, 96px);
}

.page-about .about-sec__title {
  margin: 10px 0 0;
  font-family: var(--mbx-font-body);
  font-size: clamp(25px, 4.2vw, 42px);
  font-weight: 300;
  line-height: 1.14;
  letter-spacing: -0.025em;
  color: var(--mbx-fog);
}

.page-about .about-sec__title em {
  font-style: normal;
  font-weight: 800;
  color: var(--mbx-cyan);
}

.page-about .about-sec__lead {
  margin: 16px 0 0;
  max-width: 62ch;
  color: var(--mbx-mute);
  font-size: clamp(15px, 1.5vw, 16px);
  line-height: 1.85;
}

.page-about .about-sec__note {
  margin: clamp(18px, 3vw, 26px) 0 0;
  padding-left: 14px;
  border-left: 2px solid var(--mbx-amber);
  font-size: 14px;
  line-height: 1.8;
  color: var(--mbx-mute);
}

.page-about .about-link {
  color: var(--mbx-cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(53, 224, 224, 0.45);
}

.page-about .about-link:hover {
  color: var(--mbx-amber);
  border-bottom-color: rgba(245, 184, 75, 0.6);
}

/* ---------- 档案卡 ---------- */

.page-about .about-archive {
  display: grid;
  gap: clamp(14px, 2.4vw, 20px);
  margin-top: clamp(22px, 3.5vw, 34px);
}

.page-about .about-card {
  position: relative;
  padding: clamp(20px, 3vw, 30px);
  background: var(--about-card-bg);
  clip-path: polygon(0 0, calc(100% - var(--about-cut)) 0, 100% var(--about-cut), 100% 100%, 0 100%);
  transition: transform 220ms var(--mbx-ease);
}

.page-about .about-card::after {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 46px;
  height: 3px;
  background: var(--mbx-red);
}

.page-about .about-card:hover {
  transform: translateY(-4px);
}

.page-about .about-card__tag {
  margin: 0 0 12px;
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--mbx-amber);
}

.page-about .about-card__title {
  margin: 0 0 10px;
  font-size: 18px;
  font-weight: 700;
  line-height: 1.4;
  color: var(--mbx-fog);
}

.page-about .about-card__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--mbx-mute);
}

/* ---------- 改版演进 ---------- */

.page-about .about-split {
  display: grid;
  gap: clamp(20px, 3vw, 36px);
  margin-top: clamp(22px, 3.5vw, 34px);
}

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

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

.page-about .about-split__cap {
  margin-top: 10px;
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--mbx-mute);
}

.page-about .about-fold {
  border-bottom: 1px solid var(--mbx-line);
}

.page-about .about-fold:first-child {
  border-top: 1px solid var(--mbx-line);
}

.page-about .about-fold__sum {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 16px 0;
  cursor: pointer;
  list-style: none;
  font-size: 16px;
  font-weight: 600;
  color: var(--mbx-fog);
  transition: color 200ms var(--mbx-ease);
}

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

.page-about .about-fold__sum::after {
  content: "+";
  margin-left: auto;
  font-family: var(--mbx-font-mono);
  color: var(--mbx-cyan);
}

.page-about .about-fold[open] .about-fold__sum::after {
  content: "–";
  color: var(--mbx-amber);
}

.page-about .about-fold__sum:hover {
  color: var(--mbx-cyan);
}

.page-about .about-fold__num {
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--mbx-amber);
}

.page-about .about-fold p {
  margin: 0 0 18px;
  padding-left: 32px;
  font-size: 15px;
  line-height: 1.85;
  color: var(--mbx-mute);
}

.page-about .about-split__link {
  margin-top: 24px;
}

/* ---------- 内容运营 ---------- */

.page-about .about-band {
  margin: clamp(22px, 3.5vw, 34px) 0 0;
}

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

.page-about .about-band__cap {
  margin-top: 10px;
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--mbx-mute);
}

.page-about .about-flow {
  display: grid;
  gap: 14px;
  margin-top: clamp(22px, 3.5vw, 32px);
  counter-reset: aboutflow;
}

.page-about .about-flow__step {
  position: relative;
  padding: clamp(18px, 2.6vw, 24px);
  background: var(--mbx-panel);
  border-left: 2px solid var(--mbx-blue);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 14px), calc(100% - 14px) 100%, 0 100%);
}

.page-about .about-flow__step:nth-child(2) {
  border-left-color: var(--mbx-amber);
}

.page-about .about-flow__step:nth-child(3) {
  border-left-color: var(--mbx-cyan);
}

.page-about .about-flow__num {
  margin: 0 0 8px;
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--mbx-mute);
}

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

.page-about .about-flow__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--mbx-mute);
}

.page-about .about-stats {
  display: grid;
  gap: 14px;
  margin: clamp(22px, 3.5vw, 32px) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-stats__item {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 16px 0 0;
  border-top: 1px solid var(--mbx-line);
}

.page-about .about-stats__num {
  font-family: var(--mbx-font-display);
  font-size: clamp(24px, 3.2vw, 32px);
  line-height: 1.1;
  color: var(--mbx-cyan);
  letter-spacing: -0.01em;
}

.page-about .about-stats__key {
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--mbx-mute);
}

/* ---------- 赛季规划 ---------- */

.page-about .about-season {
  display: grid;
  gap: 14px;
  margin-top: clamp(22px, 3.5vw, 32px);
}

.page-about .about-season__col {
  padding: clamp(18px, 2.6vw, 26px);
  background: var(--about-card-bg);
  clip-path: polygon(0 0, calc(100% - var(--about-cut)) 0, 100% var(--about-cut), 100% 100%, 0 100%);
}

.page-about .about-season__label {
  margin: 0 0 14px;
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--mbx-amber);
}

.page-about .about-season__list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 10px;
  counter-reset: season;
}

.page-about .about-season__list li {
  position: relative;
  padding-left: 24px;
  font-size: 15px;
  line-height: 1.7;
  color: var(--mbx-fog);
  counter-increment: season;
}

.page-about .about-season__list li::before {
  content: counter(season, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: 1px;
  font-family: var(--mbx-font-mono);
  font-size: 11px;
  color: var(--mbx-mute);
}

/* ---------- 协作 ---------- */

.page-about .about-coop {
  margin: clamp(22px, 3.5vw, 32px) 0 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--mbx-line);
}

.page-about .about-coop__item {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  gap: 12px;
  padding: 18px 0;
  border-bottom: 1px solid var(--mbx-line);
  transition: background 200ms var(--mbx-ease);
}

.page-about .about-coop__item:hover {
  background: rgba(53, 224, 224, 0.05);
}

.page-about .about-coop__num {
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--mbx-amber);
  padding-top: 3px;
}

.page-about .about-coop__title {
  margin: 0 0 6px;
  font-size: 17px;
  font-weight: 700;
  color: var(--mbx-fog);
}

.page-about .about-coop__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--mbx-mute);
}

.page-about .about-bar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 18px;
  margin-top: clamp(22px, 3.5vw, 30px);
  padding: clamp(20px, 3vw, 28px);
  background: rgba(122, 14, 30, 0.32);
  border: 1px solid rgba(179, 32, 52, 0.5);
  clip-path: polygon(0 0, calc(100% - 20px) 0, 100% 20px, 100% 100%, 0 100%);
}

.page-about .about-bar__text p {
  margin: 0;
}

.page-about .about-bar__text p:first-child {
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--mbx-amber);
  margin-bottom: 8px;
}

.page-about .about-bar__text p:last-child {
  font-size: 15px;
  line-height: 1.75;
  color: var(--mbx-fog);
  max-width: 46ch;
}

.page-about .about-bar__btn {
  flex: 0 0 auto;
}

/* ---------- 下一阶段 ---------- */

.page-about .about-next {
  display: grid;
  gap: 14px;
  margin-top: clamp(22px, 3.5vw, 32px);
}

.page-about .about-next__item {
  padding: clamp(18px, 2.6vw, 24px);
  border: 1px solid var(--mbx-line);
  border-bottom-color: transparent;
  background: linear-gradient(180deg, rgba(21, 26, 33, 0.9), rgba(11, 13, 16, 0.4));
  transition: border-color 200ms var(--mbx-ease), transform 200ms var(--mbx-ease);
}

.page-about .about-next__item:hover {
  border-color: rgba(53, 224, 224, 0.5);
  transform: translateY(-3px);
}

.page-about .about-next__mark {
  margin: 0 0 10px;
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--mbx-amber);
}

.page-about .about-next__title {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 700;
  color: var(--mbx-fog);
}

.page-about .about-next__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--mbx-mute);
}

.page-about .about-cta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(24px, 3.5vw, 34px);
}

/* ---------- 响应式 ---------- */

@media (min-width: 720px) {
  .page-about .about-archive {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-archive .about-card:nth-child(even) {
    margin-top: 34px;
  }

  .page-about .about-flow {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 16px;
  }

  .page-about .about-stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 22px;
  }

  .page-about .about-season {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 20px;
  }

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

  .page-about .about-split {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    align-items: start;
  }
}

@media (min-width: 980px) {
  .page-about .about-cover__grid {
    grid-template-columns: 1.1fr 0.9fr;
    gap: clamp(36px, 5vw, 64px);
  }

  .page-about .about-body {
    grid-template-columns: 210px minmax(0, 1fr);
    gap: clamp(36px, 5vw, 72px);
    align-items: start;
  }

  .page-about .about-rail {
    position: sticky;
    top: clamp(104px, 14vh, 136px);
  }

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

  .page-about .about-rail__item {
    display: grid;
    grid-template-columns: 2.4ch minmax(0, 1fr);
    gap: 4px 10px;
    padding: 12px 0 12px 16px;
    border: 0;
    border-left: 1px solid var(--mbx-line);
    border-radius: 0;
    white-space: normal;
    background: none;
  }

  .page-about .about-rail__item:hover,
  .page-about .about-rail__item:focus-visible {
    border-left-color: var(--mbx-cyan);
    background: none;
  }

  .page-about .about-rail__num {
    grid-column: 1;
    grid-row: 1;
  }

  .page-about .about-rail__name {
    grid-column: 2;
    grid-row: 1;
  }

  .page-about .about-rail__hint {
    display: block;
    grid-column: 2;
    grid-row: 2;
    font-size: 12px;
    line-height: 1.5;
    color: var(--mbx-mute);
    opacity: 0;
    max-height: 0;
    overflow: hidden;
    transition: opacity 200ms var(--mbx-ease), max-height 220ms var(--mbx-ease);
  }

  .page-about .about-rail__item:hover .about-rail__hint,
  .page-about .about-rail__item:focus-visible .about-rail__hint {
    opacity: 1;
    max-height: 60px;
  }

  .page-about .about-sec__lead {
    margin-top: 20px;
  }
}

@media (min-width: 1240px) {
  .page-about .about-cover__figure {
    margin-left: auto;
  }

  .page-about .about-sec__title {
    max-width: 20ch;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-card,
  .page-about .about-next__item,
  .page-about .about-rail__hint,
  .page-about .about-rail__item {
    transition: none;
  }

  .page-about .about-card:hover,
  .page-about .about-next__item:hover {
    transform: none;
  }
}