.page-about {
  --about-rail: 128px;
  --about-gap: clamp(20px, 3vw, 56px);
  display: block;
}

/* ---------- 面包屑 ---------- */
.page-about .about-crumbs {
  padding-top: clamp(18px, 3vw, 32px);
}

/* ---------- 首屏 ---------- */
.page-about .about-masthead {
  border-bottom: 1px solid var(--line);
  background:
    radial-gradient(circle at 84% 8%, rgba(63, 201, 224, 0.10), transparent 55%),
    radial-gradient(circle at 4% 92%, rgba(255, 92, 43, 0.10), transparent 52%);
}

.page-about .about-masthead__inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(28px, 4vw, 48px);
  padding: clamp(30px, 5vw, 60px) 0 clamp(38px, 6vw, 80px);
}

.page-about .about-masthead__lede .eyebrow {
  margin: 0;
}

.page-about .about-masthead h1 {
  margin: 14px 0 0;
  font-size: clamp(2.2rem, 5.6vw, 4.4rem);
  font-weight: 200;
  line-height: 1.08;
  letter-spacing: -0.02em;
  color: var(--paper);
  max-width: 18ch;
}

.page-about .about-masthead__intro {
  margin: 24px 0 0;
  max-width: 62ch;
  font-size: var(--step-3);
  line-height: 1.8;
  color: var(--muted);
}

.page-about .about-masthead__side {
  display: flex;
  flex-direction: column;
  border-top: 1px solid var(--line);
}

.page-about .about-fact {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-fact__num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(1.4rem, 3vw, 1.9rem);
  line-height: 1;
  color: var(--score);
  letter-spacing: -0.02em;
}

.page-about .about-fact__label {
  font-size: var(--step-1);
  letter-spacing: 0.14em;
  color: var(--muted);
  text-align: right;
}

@media (min-width: 900px) {
  .page-about .about-masthead__inner {
    grid-template-columns: minmax(0, 8fr) minmax(250px, 3fr);
    align-items: end;
    gap: clamp(32px, 5vw, 84px);
  }
}

/* ---------- 章节骨架 ---------- */
.page-about .about-chapter + .about-chapter {
  border-top: 1px solid var(--line);
}

.page-about .about-chapter__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(14px, 2vw, 22px);
  padding: clamp(40px, 6vw, 88px) 0;
}

.page-about .about-chapter__rail {
  display: flex;
  align-items: baseline;
  gap: 12px;
}

.page-about .about-chapter__num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(1.5rem, 3.2vw, 2.4rem);
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--line);
  transform: rotate(var(--tilt));
}

.page-about .about-chapter__tag {
  font-size: var(--step-1);
  letter-spacing: 0.18em;
  color: var(--score);
  text-transform: uppercase;
}

.page-about .about-chapter__main h2 {
  margin: 0 0 20px;
  font-size: clamp(1.5rem, 3vw, 2.25rem);
  font-weight: 300;
  line-height: 1.3;
  letter-spacing: -0.01em;
  color: var(--paper);
}

.page-about .about-chapter__main p {
  margin: 0 0 18px;
  max-width: 68ch;
  font-size: var(--step-3);
  line-height: 1.8;
  color: var(--muted);
}

@media (min-width: 860px) {
  .page-about .about-chapter__grid {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: clamp(24px, 4vw, 72px);
  }

  .page-about .about-chapter__rail {
    position: sticky;
    top: 84px;
    align-self: start;
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
  }
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: clamp(24px, 4vw, 40px) 0 0;
  aspect-ratio: 3 / 2;
}

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

.page-about .about-figure--book {
  aspect-ratio: 4 / 3;
}

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

/* ---------- 联赛色带 ---------- */
.page-about .about-leagues {
  list-style: none;
  margin: 0 0 36px;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  border-top: 1px solid var(--line);
  border-left: 1px solid var(--line);
}

.page-about .about-leagues__item {
  position: relative;
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 16px 12px 14px;
  border-right: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
  font-size: var(--step-3);
  color: var(--paper);
  letter-spacing: 0.04em;
}

.page-about .about-leagues__item::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 3px;
  background: linear-gradient(90deg, var(--pitch), var(--pitch-deep));
}

.page-about .about-leagues__idx {
  font-family: var(--font-mono);
  font-size: var(--step-1);
  letter-spacing: 0.06em;
  color: var(--muted);
}

@media (min-width: 620px) {
  .page-about .about-leagues {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

@media (min-width: 1060px) {
  .page-about .about-leagues {
    grid-template-columns: repeat(6, minmax(0, 1fr));
  }
}

/* ---------- 内容清单 ---------- */
.page-about .about-list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.page-about .about-list__item {
  display: grid;
  grid-template-columns: 40px minmax(0, 1fr);
  gap: 0 18px;
  padding: 22px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-list__num {
  font-family: var(--font-mono);
  font-size: var(--step-2);
  font-weight: 700;
  color: var(--pitch);
  padding-top: 4px;
}

.page-about .about-list__text h3 {
  margin: 0 0 8px;
  font-size: var(--step-3);
  font-weight: 500;
  color: var(--paper);
}

.page-about .about-list__text p {
  margin: 0;
  max-width: 64ch;
  font-size: var(--step-2);
  line-height: 1.75;
  color: var(--muted);
}

/* ---------- 团队分工 ---------- */
.page-about .about-team {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-team__row {
  display: grid;
  grid-template-columns: 60px minmax(0, 1fr);
  grid-template-rows: auto auto auto;
  column-gap: 18px;
  padding: 22px 0;
  border-bottom: 1px solid var(--line);
}

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

.page-about .about-team__num {
  grid-column: 1;
  grid-row: 1 / span 3;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(1.4rem, 3vw, 1.9rem);
  line-height: 1;
  color: var(--score);
  padding-top: 2px;
}

.page-about .about-team__name {
  grid-column: 2;
  font-size: var(--step-3);
  font-weight: 500;
  color: var(--paper);
}

.page-about .about-team__bar {
  grid-column: 2;
  display: block;
  position: relative;
  height: 3px;
  margin: 12px 0 10px;
  background: var(--ink-2);
}

.page-about .about-team__bar::after {
  content: "";
  display: block;
  height: 100%;
  width: var(--w, 0);
  background: linear-gradient(90deg, var(--pitch), var(--lake));
}

.page-about .about-team__row:nth-child(1) { --w: 27.3%; }
.page-about .about-team__row:nth-child(2) { --w: 36.4%; }
.page-about .about-team__row:nth-child(3) { --w: 22.7%; }
.page-about .about-team__row:nth-child(4) { --w: 13.6%; }

.page-about .about-team__desc {
  grid-column: 2;
  max-width: 62ch;
  font-size: var(--step-2);
  line-height: 1.7;
  color: var(--muted);
}

/* ---------- 流程 ---------- */
.page-about .about-flow {
  list-style: none;
  margin: 0 0 8px;
  padding: 0;
}

.page-about .about-flow__step {
  position: relative;
  padding: 0 0 30px 26px;
  border-left: 1px solid var(--line);
}

.page-about .about-flow__step:last-child {
  padding-bottom: 4px;
}

.page-about .about-flow__step::before {
  content: "";
  position: absolute;
  left: -4px;
  top: 7px;
  width: 7px;
  height: 7px;
  background: var(--score);
}

.page-about .about-flow__time {
  display: block;
  margin-bottom: 6px;
  font-family: var(--font-mono);
  font-size: var(--step-1);
  letter-spacing: 0.1em;
  color: var(--alert);
}

.page-about .about-flow__step h3 {
  margin: 0 0 8px;
  font-size: var(--step-3);
  font-weight: 500;
  color: var(--paper);
}

.page-about .about-flow__step p {
  margin: 0;
  max-width: 64ch;
  font-size: var(--step-2);
  line-height: 1.75;
  color: var(--muted);
}

/* ---------- 时间线 ---------- */
.page-about .about-timeline {
  list-style: none;
  margin: 0 0 8px;
  padding: 0;
  border-top: 1px solid var(--line);
}

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

.page-about .about-timeline summary {
  position: relative;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 6px 18px;
  padding: 20px 44px 20px 0;
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-timeline summary::marker {
  content: "";
}

.page-about .about-timeline summary::after {
  content: "+";
  position: absolute;
  right: 4px;
  top: 17px;
  font-family: var(--font-mono);
  font-size: var(--step-3);
  line-height: 1;
  color: var(--score);
}

.page-about .about-timeline details[open] summary::after {
  content: "−";
  color: var(--lake);
}

.page-about .about-timeline summary:hover .about-timeline__title {
  color: var(--lake);
}

.page-about .about-timeline__year {
  flex: 0 0 auto;
  min-width: 92px;
  font-family: var(--font-mono);
  font-size: var(--step-1);
  letter-spacing: 0.12em;
  color: var(--pitch);
}

.page-about .about-timeline__title {
  flex: 1 1 auto;
  min-width: 0;
  font-size: var(--step-3);
  font-weight: 400;
  color: var(--paper);
  transition: color 200ms var(--ease);
}

.page-about .about-timeline__body {
  padding: 0 44px 24px 0;
}

.page-about .about-timeline__body p {
  margin: 0;
  max-width: 66ch;
  font-size: var(--step-2);
  line-height: 1.75;
  color: var(--muted);
}

/* ---------- 社群合作 ---------- */
.page-about .about-community {
  display: grid;
  gap: clamp(20px, 3vw, 32px);
  margin-top: 10px;
  padding-top: clamp(22px, 3vw, 32px);
  border-top: 1px solid var(--line);
}

.page-about .about-community__stat {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.page-about .about-community__num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(3rem, 8vw, 5rem);
  line-height: 0.9;
  letter-spacing: -0.04em;
  color: var(--pitch);
  transform: rotate(var(--tilt));
  transform-origin: left center;
}

.page-about .about-community__label {
  max-width: 18ch;
  font-size: var(--step-1);
  letter-spacing: 0.14em;
  line-height: 1.6;
  color: var(--muted);
}

.page-about .about-community__text p {
  margin: 0 0 16px;
  max-width: 64ch;
  font-size: var(--step-2);
  line-height: 1.78;
  color: var(--muted);
}

.page-about .about-community__text p:last-child {
  margin-bottom: 0;
}

@media (min-width: 760px) {
  .page-about .about-community {
    grid-template-columns: minmax(0, 4fr) minmax(0, 7fr);
    gap: clamp(28px, 4vw, 56px);
  }
}

/* ---------- 三件事 ---------- */
.page-about .about-pledges {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-pledges > li {
  background: var(--ink);
  padding: clamp(22px, 3vw, 34px);
}

.page-about .about-pledges__idx {
  display: block;
  margin-bottom: 12px;
  font-family: var(--font-mono);
  font-size: var(--step-2);
  letter-spacing: 0.1em;
  color: var(--lake);
}

.page-about .about-pledges h3 {
  margin: 0 0 10px;
  font-size: var(--step-3);
  font-weight: 500;
  color: var(--paper);
}

.page-about .about-pledges p {
  margin: 0;
  max-width: 56ch;
  font-size: var(--step-2);
  line-height: 1.78;
  color: var(--muted);
}

@media (min-width: 820px) {
  .page-about .about-pledges {
    grid-template-columns: 1fr 1fr;
  }

  .page-about .about-pledges > li:first-child {
    grid-column: 1 / -1;
  }

  .page-about .about-pledges > li:first-child p {
    max-width: 78ch;
  }
}

/* ---------- 结尾指引 ---------- */
.page-about .about-outro {
  border-top: 1px solid var(--line);
  padding: clamp(42px, 6vw, 88px) 0 clamp(48px, 7vw, 96px);
  background: linear-gradient(180deg, transparent, rgba(18, 32, 58, 0.65));
}

.page-about .about-outro__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(24px, 4vw, 48px);
}

.page-about .about-outro__lede .eyebrow {
  margin: 0 0 12px;
}

.page-about .about-outro h2 {
  margin: 0 0 16px;
  font-size: clamp(1.5rem, 3vw, 2.25rem);
  font-weight: 300;
  line-height: 1.3;
  color: var(--paper);
}

.page-about .about-outro__lede p {
  margin: 0;
  max-width: 62ch;
  font-size: var(--step-3);
  line-height: 1.8;
  color: var(--muted);
}

.page-about .about-outro__links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-content: start;
}

@media (min-width: 860px) {
  .page-about .about-outro__grid {
    grid-template-columns: minmax(0, 6fr) minmax(0, 5fr);
    align-items: start;
    gap: clamp(32px, 5vw, 72px);
  }

  .page-about .about-outro__links {
    justify-content: flex-end;
  }
}