.page-about {
  --about-rail-w: 92px;
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumb {
  padding: 18px 0 0;
}
.page-about .breadcrumb__list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: .04em;
  color: var(--slate);
}
.page-about .breadcrumb__item a {
  color: var(--lake);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: border-color .2s var(--ease), color .2s var(--ease);
}
.page-about .breadcrumb__item a:hover,
.page-about .breadcrumb__item a:focus-visible {
  border-bottom-color: var(--sun);
  color: var(--sun);
}
.page-about .breadcrumb__item + .breadcrumb__item::before {
  content: "/";
  margin-right: 8px;
  color: var(--line);
}
.page-about .breadcrumb__item[aria-current="page"] {
  color: var(--ink);
}

/* ---------- 左侧章节指示条 ---------- */
.page-about .about-rail {
  display: none;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  margin-top: 18px;
  padding: clamp(44px, 7vw, 96px) 0 clamp(44px, 6vw, 80px);
  background: linear-gradient(128deg, var(--deep) 0%, var(--lake) 72%, #0e6f9d 100%);
  color: var(--snow);
}
.page-about .about-hero__slash {
  position: absolute;
  top: -20%;
  right: -12%;
  width: 58%;
  height: 140%;
  background: linear-gradient(180deg, rgba(255, 106, 43, .22), rgba(39, 211, 192, .06));
  transform: skewX(-16deg);
  pointer-events: none;
}
.page-about .about-hero__inner {
  position: relative;
  z-index: 2;
  display: grid;
  gap: clamp(28px, 5vw, 48px);
  grid-template-columns: 1fr;
}
.page-about .about-hero__title {
  margin: 14px 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(34px, 7.4vw, 76px);
  line-height: 1.06;
  letter-spacing: -.01em;
}
.page-about .about-hero__lede {
  margin: 20px 0 0;
  max-width: 40em;
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.85;
  color: rgba(247, 250, 252, .88);
}
.page-about .about-hero__side {
  padding: 22px 20px 24px;
  background: rgba(6, 47, 74, .48);
  border: 1px solid var(--line-dark);
  clip-path: polygon(0 0, calc(100% - var(--cut)) 0, 100% var(--cut), 100% 100%, var(--cut) 100%, 0 calc(100% - var(--cut)));
  backdrop-filter: blur(2px);
}
.page-about .about-hero__side-title {
  margin: 0 0 14px;
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--amber);
  text-transform: uppercase;
}
.page-about .about-hero__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 16px 18px;
  margin: 0;
}
.page-about .about-hero__stat dt {
  font-size: 12px;
  color: rgba(247, 250, 252, .62);
  letter-spacing: .04em;
}
.page-about .about-hero__stat dd {
  margin: 4px 0 0;
  display: flex;
  align-items: baseline;
  gap: 3px;
}
.page-about .about-hero__stat .data-num {
  font-family: var(--font-data);
  font-weight: 600;
  font-size: clamp(28px, 4vw, 38px);
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--snow);
}
.page-about .about-hero__stat:nth-child(3) .data-num {
  color: var(--amber);
}
.page-about .about-hero__unit {
  font-size: 12px;
  color: rgba(247, 250, 252, .6);
}

/* ---------- 通用排版 ---------- */
.page-about .about-h2 {
  margin: 12px 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(26px, 4.4vw, 48px);
  line-height: 1.16;
  letter-spacing: -.01em;
  color: var(--ink);
  scroll-margin-top: 130px;
}
.page-about .about-h2--dark {
  color: var(--snow);
}
.page-about .about-p {
  margin: 16px 0 0;
  max-width: 34em;
  font-size: 15px;
  line-height: 1.9;
  color: var(--ink);
}
.page-about .about-p--dark {
  color: rgba(247, 250, 252, .82);
}
.page-about section[id] {
  scroll-margin-top: 120px;
}

/* ---------- 区块一：起点 ---------- */
.page-about .about-origin {
  padding-top: clamp(48px, 6vw, 84px);
  padding-bottom: clamp(44px, 6vw, 80px);
}
.page-about .about-origin__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(26px, 5vw, 44px);
}
.page-about .about-origin__aside {
  padding: 24px 22px 26px;
  background: var(--snow);
  border: 1px solid var(--line);
  box-shadow: 0 12px 30px -22px rgba(28, 35, 41, .5);
}
.page-about .about-origin__aside .cut-card__label {
  margin: 0;
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--sun);
}
.page-about .about-origin__status {
  margin: 10px 0 0;
  font-size: 14px;
  color: var(--lake);
  letter-spacing: .02em;
}
.page-about .about-origin__list {
  margin: 16px 0 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line);
}
.page-about .about-origin__list li {
  padding: 11px 0 11px 18px;
  position: relative;
  font-size: 14px;
  line-height: 1.7;
  color: var(--ink);
  border-bottom: 1px solid var(--line);
}
.page-about .about-origin__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 18px;
  width: 8px;
  height: 8px;
  background: var(--amber);
  clip-path: polygon(0 0, 100% 0, 100% 100%);
}
.page-about .about-origin__btn {
  margin-top: 20px;
  display: inline-block;
}

/* ---------- 区块二：六个赛季时间轴 ---------- */
.page-about .about-seasons {
  position: relative;
  overflow: hidden;
  padding-top: clamp(46px, 6vw, 82px);
  padding-bottom: clamp(40px, 5vw, 64px);
}
.page-about .about-band {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px 16px;
}
.page-about .about-band__zh {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 13px;
  letter-spacing: .22em;
  color: var(--amber);
}
.page-about .about-band__en {
  font-size: 11px;
  letter-spacing: .18em;
  color: rgba(247, 250, 252, .5);
}
.page-about .about-seasons__figure {
  margin: clamp(22px, 4vw, 36px) 0 0;
  position: relative;
}
.page-about .about-seasons__figure img {
  display: block;
  width: 100%;
  height: auto;
  max-height: 380px;
  object-fit: cover;
  object-position: center 40%;
  opacity: .82;
}
.page-about .about-seasons__figure .frame__caption {
  display: block;
  padding: 8px 0 0;
  font-family: var(--font-data);
  font-size: 11px;
  letter-spacing: .08em;
  color: rgba(247, 250, 252, .55);
}

.page-about .about-axis {
  margin-top: clamp(24px, 4vw, 40px);
  border-top: 1px solid var(--line-dark);
  padding-top: 26px;
  position: relative;
}
.page-about .about-axis__track {
  display: flex;
  gap: 16px;
  overflow-x: auto;
  scroll-snap-type: x mandatory;
  padding-bottom: 14px;
  -webkit-overflow-scrolling: touch;
}
.page-about .about-axis__track > * {
  scroll-snap-align: start;
}
.page-about .season {
  flex: 0 0 258px;
  position: relative;
  padding: 22px 18px 20px;
  background: rgba(247, 250, 252, .06);
  border: 1px solid var(--line-dark);
  border-top: 2px solid rgba(255, 179, 71, .35);
  clip-path: polygon(0 0, calc(100% - var(--cut)) 0, 100% var(--cut), 100% 100%, var(--cut) 100%, 0 calc(100% - var(--cut)));
  transition: transform .24s var(--ease), background .24s var(--ease), border-color .24s var(--ease);
}
.page-about .season:hover,
.page-about .season:focus-visible {
  transform: translateY(-4px);
  background: rgba(247, 250, 252, .1);
  border-top-color: var(--sun);
  outline: none;
}
.page-about .season:focus-visible {
  box-shadow: 0 0 0 2px var(--neon);
}
.page-about .season__dot {
  display: block;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--amber);
  box-shadow: 0 0 0 4px rgba(255, 179, 71, .16);
  margin-bottom: 14px;
}
.page-about .season__no {
  margin: 0;
  font-size: 12px;
  letter-spacing: .2em;
  color: var(--neon);
}
.page-about .season__title {
  margin: 8px 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 18px;
  line-height: 1.35;
  color: var(--snow);
}
.page-about .season__text {
  margin: 10px 0 0;
  font-size: 13px;
  line-height: 1.8;
  color: rgba(247, 250, 252, .72);
}
.page-about .about-axis__hint {
  margin: 8px 0 0;
  font-size: 11px;
  letter-spacing: .16em;
  color: rgba(247, 250, 252, .45);
}

.page-about .about-seasons__texture {
  margin-top: clamp(30px, 5vw, 54px);
  line-height: 0;
  opacity: .28;
}
.page-about .about-seasons__texture img {
  display: block;
  width: 100%;
  height: auto;
  max-height: 220px;
  object-fit: cover;
}

/* ---------- 区块三：三条主线 ---------- */
.page-about .about-lines {
  padding-top: clamp(48px, 6vw, 84px);
  padding-bottom: clamp(48px, 6vw, 84px);
}
.page-about .about-lines__intro {
  max-width: 40em;
}
.page-about .about-lines__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
  margin-top: clamp(26px, 4vw, 40px);
}
.page-about .line-strip {
  position: relative;
  padding: 26px 22px 24px;
  background: var(--snow);
  border: 1px solid var(--line);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--cut)), calc(100% - var(--cut)) 100%, 0 100%);
  transition: transform .24s var(--ease), box-shadow .24s var(--ease);
}
.page-about .line-strip::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 6px;
}
.page-about .line-strip--a::before {
  background: linear-gradient(180deg, var(--lake), var(--neon));
}
.page-about .line-strip--b::before {
  background: linear-gradient(180deg, var(--sun), var(--amber));
}
.page-about .line-strip--c::before {
  background: linear-gradient(180deg, var(--away), var(--home));
}
.page-about .line-strip:hover,
.page-about .line-strip:focus-within {
  transform: translateY(-4px);
  box-shadow: 0 22px 40px -30px rgba(28, 35, 41, .65);
}
.page-about .line-strip__tag {
  margin: 0;
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--slate);
}
.page-about .line-strip--b .line-strip__tag {
  color: #b8431a;
}
.page-about .line-strip__title {
  margin: 10px 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(20px, 2.6vw, 26px);
  line-height: 1.3;
  color: var(--ink);
}
.page-about .line-strip__text {
  margin: 12px 0 0;
  font-size: 14.5px;
  line-height: 1.88;
  color: var(--ink);
}
.page-about .line-strip__list {
  margin: 14px 0 0;
  padding: 14px 0 0;
  list-style: none;
  border-top: 1px dashed var(--line);
}
.page-about .line-strip__list li {
  position: relative;
  padding-left: 16px;
  font-size: 13px;
  line-height: 1.9;
  color: var(--slate);
}
.page-about .line-strip__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 11px;
  width: 6px;
  height: 6px;
  background: var(--slate);
}
.page-about .line-strip__link {
  display: inline-block;
  margin-top: 18px;
  font-family: var(--font-data);
  font-size: 12.5px;
  letter-spacing: .06em;
  color: var(--lake);
  text-decoration: none;
  border-bottom: 1px solid var(--lake);
  padding-bottom: 2px;
  transition: color .2s var(--ease), border-color .2s var(--ease);
}
.page-about .line-strip__link:hover,
.page-about .line-strip__link:focus-visible {
  color: var(--sun);
  border-bottom-color: var(--sun);
}

/* ---------- 区块四：团队 ---------- */
.page-about .about-team {
  padding-top: clamp(48px, 6vw, 84px);
  padding-bottom: clamp(48px, 6vw, 84px);
}
.page-about .about-team__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(26px, 5vw, 44px);
}
.page-about .donut-wrap {
  display: flex;
  flex-wrap: wrap;
  align-items: flex-start;
  gap: clamp(22px, 4vw, 40px);
  margin-top: clamp(24px, 4vw, 36px);
}
.page-about .donut {
  position: relative;
  flex: 0 0 auto;
  width: 168px;
  height: 168px;
  border-radius: 50%;
  background: conic-gradient(
    var(--lake) 0deg 164.3deg,
    var(--amber) 164.3deg 273.9deg,
    var(--away) 273.9deg 360deg
  );
  display: grid;
  place-items: center;
  transform: rotate(-6deg);
}
.page-about .donut::after {
  content: "";
  position: absolute;
  inset: 0;
  border-radius: 50%;
  border: 1px solid rgba(247, 250, 252, .22);
}
.page-about .donut__hole {
  width: 96px;
  height: 96px;
  border-radius: 50%;
  background: var(--deep);
  color: var(--snow);
  display: grid;
  place-items: center;
  font-size: 26px;
  font-weight: 600;
  letter-spacing: -.02em;
  transform: rotate(6deg);
}
.page-about .donut-legend {
  flex: 1 1 260px;
  margin: 0;
  padding: 0;
  list-style: none;
  min-width: 0;
}
.page-about .donut-legend__item {
  position: relative;
  display: grid;
  grid-template-columns: 12px 1fr auto;
  align-items: center;
  gap: 10px;
  padding: 12px 0;
  border-bottom: 1px solid var(--line-dark);
  cursor: default;
}
.page-about .donut-legend__swatch {
  width: 12px;
  height: 12px;
  clip-path: polygon(0 0, 100% 0, 100% 100%);
}
.page-about .donut-legend__item--data .donut-legend__swatch { background: var(--lake); }
.page-about .donut-legend__item--edit .donut-legend__swatch { background: var(--amber); }
.page-about .donut-legend__item--tech .donut-legend__swatch { background: var(--away); }
.page-about .donut-legend__name {
  font-size: 14.5px;
  color: var(--snow);
  letter-spacing: .02em;
}
.page-about .donut-legend__num {
  font-size: 20px;
  color: var(--snow);
}
.page-about .donut-legend__note {
  grid-column: 2 / -1;
  max-height: 0;
  overflow: hidden;
  font-size: 13px;
  line-height: 1.8;
  color: rgba(247, 250, 252, .72);
  transition: max-height .3s var(--ease), margin-top .3s var(--ease);
}
.page-about .donut-legend__item:hover .donut-legend__note,
.page-about .donut-legend__item:focus-visible .donut-legend__note,
.page-about .donut-legend__item:focus-within .donut-legend__note {
  max-height: 140px;
  margin-top: 6px;
}
.page-about .donut-legend__item:focus-visible {
  outline: 2px solid var(--neon);
  outline-offset: 4px;
}
.page-about .about-team__aside {
  align-self: start;
  padding: 22px 20px;
  border-left: 3px solid var(--sun);
  background: rgba(247, 250, 252, .05);
}
.page-about .about-team__quote {
  margin: 0;
  font-size: 15px;
  line-height: 1.9;
  color: rgba(247, 250, 252, .88);
}
.page-about .about-team__meta {
  margin: 14px 0 0;
  font-size: 11.5px;
  letter-spacing: .14em;
  color: var(--amber);
}

/* ---------- 区块五：质控 ---------- */
.page-about .about-quality {
  padding-top: clamp(48px, 6vw, 84px);
  padding-bottom: clamp(48px, 6vw, 84px);
}
.page-about .about-quality__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(26px, 5vw, 44px);
}
.page-about .about-quality__steps {
  margin: 24px 0 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line);
}
.page-about .about-quality__steps li {
  display: grid;
  grid-template-columns: 40px 1fr;
  gap: 12px;
  align-items: baseline;
  padding: 14px 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--ink);
  border-bottom: 1px solid var(--line);
}
.page-about .about-quality__step-no {
  font-size: 12.5px;
  letter-spacing: .08em;
  color: var(--sun);
}
.page-about .about-quality__figure {
  margin: 0;
  position: relative;
}
.page-about .about-quality__figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  clip-path: polygon(0 0, calc(100% - var(--cut)) 0, 100% var(--cut), 100% 100%, 0 100%);
}
.page-about .about-quality__figure .frame__caption {
  display: block;
  margin-top: 10px;
  font-family: var(--font-data);
  font-size: 11.5px;
  letter-spacing: .06em;
  color: var(--slate);
}

/* ---------- 区块六：协作生态 ---------- */
.page-about .about-eco {
  padding-top: clamp(48px, 6vw, 84px);
  padding-bottom: clamp(48px, 6vw, 84px);
}
.page-about .about-eco__intro {
  max-width: 40em;
}
.page-about .eco-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
  margin-top: clamp(26px, 4vw, 40px);
}
.page-about .eco-card {
  padding: 24px 22px 26px;
  background: var(--snow);
  border: 1px solid var(--line);
  border-top: 3px solid var(--lake);
  transition: transform .24s var(--ease), box-shadow .24s var(--ease);
}
.page-about .eco-card:hover,
.page-about .eco-card:focus-within {
  transform: translateY(-4px);
  box-shadow: 0 22px 40px -30px rgba(28, 35, 41, .6);
}
.page-about .eco-card__no {
  margin: 0;
  font-family: var(--font-data);
  font-weight: 600;
  font-size: clamp(40px, 7vw, 64px);
  line-height: 1;
  letter-spacing: -.03em;
  color: var(--lake);
}
.page-about .eco-card__title {
  margin: 12px 0 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 20px;
  line-height: 1.35;
  color: var(--ink);
}
.page-about .eco-card__text {
  margin: 10px 0 0;
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--slate);
}
.page-about .eco-card--wide {
  border-top-color: var(--sun);
  background: linear-gradient(160deg, rgba(255, 106, 43, .06), rgba(11, 93, 140, .06));
}
.page-about .eco-card__list {
  margin: 14px 0 0;
  padding: 0;
  list-style: none;
}
.page-about .eco-card__list li {
  position: relative;
  padding: 10px 0 10px 20px;
  font-size: 14.5px;
  line-height: 1.85;
  color: var(--ink);
  border-bottom: 1px solid var(--line);
}
.page-about .eco-card__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 17px;
  width: 8px;
  height: 8px;
  background: var(--sun);
  clip-path: polygon(0 0, 100% 0, 100% 100%);
}
.page-about .eco-card__btn {
  margin-top: 20px;
  display: inline-block;
}

/* ---------- 收束 ---------- */
.page-about .about-next {
  padding-top: clamp(44px, 5.5vw, 76px);
  padding-bottom: clamp(44px, 5.5vw, 76px);
}
.page-about .about-next__title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(24px, 3.6vw, 38px);
  line-height: 1.2;
  color: var(--snow);
}
.page-about .about-next__links {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
  margin-top: 26px;
}
.page-about .next-link {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 16px 18px;
  text-decoration: none;
  color: var(--snow);
  background: rgba(6, 47, 74, .34);
  border: 1px solid var(--line-dark);
  clip-path: polygon(0 0, calc(100% - 12px) 0, 100% 12px, 100% 100%, 0 100%);
  transition: background .24s var(--ease), transform .24s var(--ease);
}
.page-about .next-link:hover,
.page-about .next-link:focus-visible {
  background: rgba(6, 47, 74, .6);
  transform: translateY(-4px);
}
.page-about .next-link:focus-visible {
  outline: 2px solid var(--neon);
  outline-offset: 2px;
}
.page-about .next-link__k {
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--amber);
}
.page-about .next-link__t {
  font-size: 15.5px;
  letter-spacing: .02em;
}
.page-about .about-next__note {
  margin: 22px 0 0;
  font-size: 13px;
  line-height: 1.85;
  color: rgba(247, 250, 252, .78);
  max-width: 40em;
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .about-lines__grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .eco-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
  .page-about .eco-card--wide {
    grid-column: 1 / -1;
  }
  .page-about .about-next__links {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
  .page-about .season {
    flex: 0 0 288px;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__inner {
    grid-template-columns: 62fr 34fr;
    align-items: end;
  }
  .page-about .about-origin__grid {
    grid-template-columns: 7fr 5fr;
    align-items: start;
  }
  .page-about .about-team__grid {
    grid-template-columns: 7fr 5fr;
    align-items: start;
  }
  .page-about .about-quality__grid {
    grid-template-columns: 5fr 7fr;
    align-items: start;
  }
  .page-about .about-origin__aside {
    position: sticky;
    top: 132px;
  }
}

@media (min-width: 1024px) {
  .page-about .about-hero__title {
    font-size: clamp(48px, 6.4vw, 76px);
  }
  .page-about .about-seasons__figure img {
    max-height: 460px;
  }
}

@media (min-width: 1440px) {
  .page-about .about-rail {
    display: flex;
    flex-direction: column;
    gap: 16px;
    position: fixed;
    left: 22px;
    top: 50%;
    transform: translateY(-50%);
    z-index: 20;
  }
  .page-about .about-rail__link {
    display: flex;
    align-items: center;
    gap: 8px;
    font-family: var(--font-data);
    font-size: 11px;
    letter-spacing: .06em;
    color: var(--slate);
    text-decoration: none;
    transition: color .2s var(--ease);
  }
  .page-about .about-rail__link::before {
    content: "";
    width: 16px;
    height: 2px;
    background: var(--line);
    transition: width .24s var(--ease), background .24s var(--ease);
  }
  .page-about .about-rail__link:hover,
  .page-about .about-rail__link:focus-visible {
    color: var(--sun);
  }
  .page-about .about-rail__link:hover::before,
  .page-about .about-rail__link:focus-visible::before {
    width: 30px;
    background: var(--sun);
  }
  .page-about .about-rail__link:focus-visible {
    outline: 2px solid var(--neon);
    outline-offset: 3px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .season,
  .page-about .line-strip,
  .page-about .eco-card,
  .page-about .next-link,
  .page-about .donut-legend__note {
    transition: none;
  }
}
</main>