.page-about {
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-body);
}

.page-about > .shell > .breadcrumb {
  padding: 26px 0 0;
}

/* ---------- Hero ---------- */

.page-about .about-hero {
  padding: clamp(16px, 3vw, 28px) 0 clamp(52px, 8vw, 104px);
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(32px, 5vw, 60px);
  align-items: end;
}

.page-about .about-hero .eyebrow {
  margin: 0 0 14px;
  color: var(--mint-ink);
  letter-spacing: 0.16em;
}

.page-about .about-hero .page-title {
  font-family: var(--font-display);
  font-weight: 900;
  letter-spacing: -0.025em;
  line-height: 1.1;
  font-size: clamp(32px, 6.4vw, 58px);
  color: var(--ink);
  margin: 0 0 20px;
  max-width: 20ch;
}

.page-about .about-hero .lede {
  font-size: clamp(16px, 1.6vw, 17.5px);
  line-height: 1.95;
  color: var(--graphite);
  max-width: 50ch;
  margin: 0 0 28px;
}

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

.page-about .about-hero__metrics {
  list-style: none;
  margin: 0;
  padding: 18px 0;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.page-about .about-hero__metrics li {
  padding: 0 12px;
  border-left: 1px solid var(--line);
  min-width: 0;
}

.page-about .about-hero__metrics li:first-child {
  border-left: 0;
  padding-left: 0;
}

.page-about .about-hero__metrics .num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(26px, 4vw, 36px);
  font-weight: 600;
  letter-spacing: -0.02em;
  line-height: 1;
  color: var(--ink);
}

.page-about .about-hero__metrics .m-label {
  display: block;
  margin-top: 8px;
  font-size: 13px;
  line-height: 1.5;
  color: var(--graphite);
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr);
  }
}

/* ---------- Section skeleton ---------- */

.page-about .section {
  padding: clamp(52px, 8vw, 104px) 0;
}

.page-about .section__head {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  align-items: baseline;
  gap: 12px clamp(14px, 3vw, 30px);
  padding-bottom: 20px;
  border-bottom: 1px solid var(--line);
  margin: 0 0 clamp(28px, 4vw, 46px);
}

.page-about .section__num {
  font-family: var(--font-mono);
  font-size: clamp(30px, 4.6vw, 50px);
  font-weight: 500;
  line-height: 0.9;
  letter-spacing: -0.04em;
  color: var(--mint);
}

.page-about .section__title {
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(21px, 3vw, 31px);
  letter-spacing: -0.015em;
  line-height: 1.3;
  color: var(--ink);
  margin: 0;
}

/* ---------- 01 为什么做轻 ---------- */

.page-about .about-why__grid {
  display: grid;
  gap: clamp(28px, 4vw, 48px);
  align-items: start;
}

@media (min-width: 940px) {
  .page-about .about-why__grid {
    grid-template-columns: minmax(0, 1.45fr) minmax(0, 1fr);
  }
}

.page-about .about-why .prose p {
  font-size: 16.5px;
  line-height: 1.95;
  color: var(--ink);
  margin: 0 0 1.1em;
  max-width: 66ch;
}

.page-about .about-why .prose h3 {
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--ink);
  margin: 2em 0 0.6em;
}

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

.page-about .about-why__figure .figure__caption {
  margin-top: 12px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--graphite);
}

/* ---------- 02 三支团队 ---------- */

.page-about .about-team__lede {
  font-size: 16.5px;
  line-height: 1.95;
  color: var(--graphite);
  max-width: 58ch;
  margin: 0 0 clamp(24px, 4vw, 40px);
}

.page-about .about-team__cards {
  display: grid;
  gap: 20px;
}

@media (min-width: 760px) {
  .page-about .about-team__cards {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    align-items: start;
  }
}

.page-about .about-team__card {
  padding: clamp(20px, 3vw, 28px);
  background: var(--white);
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  transition: border-color 320ms var(--ease), transform 320ms var(--ease);
}

.page-about .about-team__card:hover {
  border-color: var(--mint);
  transform: translateY(-3px);
}

@media (min-width: 760px) {
  .page-about .about-team__card--tall {
    margin-top: -20px;
    padding-bottom: clamp(38px, 5vw, 54px);
  }
}

.page-about .about-team__icon {
  width: 32px;
  height: 32px;
  display: block;
  margin: 0 0 16px;
  color: var(--mint-ink);
}

.page-about .about-team__count {
  font-size: 13px;
  color: var(--graphite);
  margin: 0 0 8px;
  letter-spacing: 0.01em;
}

.page-about .about-team__count .num {
  font-family: var(--font-mono);
  font-size: 22px;
  font-weight: 600;
  color: var(--mint-ink);
  margin-right: 4px;
  letter-spacing: -0.02em;
}

.page-about .about-team__card h3 {
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 700;
  line-height: 1.42;
  letter-spacing: -0.005em;
  color: var(--ink);
  margin: 0 0 10px;
}

.page-about .about-team__text {
  font-size: 15px;
  line-height: 1.9;
  color: var(--graphite);
  margin: 0;
}

.page-about .about-team__batches {
  list-style: none;
  margin: clamp(28px, 4vw, 44px) 0 0;
  padding: 1px 0 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

@media (min-width: 800px) {
  .page-about .about-team__batches {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

.page-about .about-team__batches li {
  padding: 22px 20px;
  background: var(--white);
  display: flex;
  flex-direction: column;
  gap: 5px;
}

.page-about .about-team__batches .num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--electric);
}

.page-about .about-team__batches strong {
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 700;
  color: var(--ink);
}

.page-about .about-team__batches span:last-child {
  font-size: 14px;
  line-height: 1.75;
  color: var(--graphite);
}

/* ---------- 03 阶段条 ---------- */

.page-about .about-stages {
  padding-bottom: clamp(52px, 8vw, 104px);
}

.page-about .about-stages__banner {
  margin: 0 0 clamp(36px, 5vw, 64px);
  overflow: hidden;
}

@media (min-width: 1240px) {
  .page-about .about-stages__banner {
    max-width: 1240px;
    margin-left: auto;
    margin-right: auto;
    border-radius: var(--radius-card);
  }
}

.page-about .about-stages__track {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: clamp(22px, 3.6vw, 30px);
  position: relative;
}

.page-about .about-stages__track::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 10px;
  bottom: 10px;
  width: 2px;
  border-radius: 2px;
  background: linear-gradient(180deg, var(--mint), var(--electric));
}

@media (min-width: 900px) {
  .page-about .about-stages__track {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: clamp(20px, 3vw, 34px);
  }
  .page-about .about-stages__track::before {
    left: 0;
    right: 0;
    top: 10px;
    bottom: auto;
    width: auto;
    height: 2px;
    background: linear-gradient(90deg, var(--mint), var(--electric));
  }
}

.page-about .about-stages__step {
  position: relative;
  padding-left: 38px;
}

@media (min-width: 900px) {
  .page-about .about-stages__step {
    padding-left: 0;
    padding-top: 38px;
  }
}

.page-about .about-stages__dot {
  position: absolute;
  left: 0;
  top: 4px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--white);
  border: 3px solid var(--electric);
  box-shadow: 0 0 0 4px rgba(45, 125, 255, 0.08);
}

@media (min-width: 900px) {
  .page-about .about-stages__dot {
    top: 4px;
  }
}

.page-about .about-stages__idx {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--mint-ink);
  margin: 0 0 8px;
}

.page-about .about-stages__step h3 {
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 700;
  letter-spacing: -0.005em;
  color: var(--ink);
  margin: 0 0 10px;
}

.page-about .about-stages__copy {
  font-size: 14.5px;
  line-height: 1.9;
  color: var(--graphite);
  margin: 0;
}

/* ---------- 04 内容原则 ---------- */

.page-about .about-principles__grid {
  display: grid;
  gap: clamp(28px, 4vw, 48px);
  align-items: start;
}

@media (min-width: 940px) {
  .page-about .about-principles__grid {
    grid-template-columns: minmax(0, 0.8fr) minmax(0, 1.2fr);
  }
  .page-about .about-principles__figure {
    position: sticky;
    top: 28px;
  }
}

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

.page-about .about-principles__figure .figure__caption {
  margin-top: 12px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--graphite);
}

.page-about .about-principles__list {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.page-about .about-rule {
  background: var(--white);
  border-left: 3px solid var(--mint);
  border-radius: 0 var(--radius-card) var(--radius-card) 0;
  overflow: hidden;
}

.page-about .about-rule summary {
  list-style: none;
  cursor: pointer;
  padding: 18px 22px;
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  grid-template-areas:
    "no name"
    "no hint";
  column-gap: 14px;
  align-items: center;
}

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

.page-about .about-rule summary:focus-visible {
  outline: 2px solid var(--electric);
  outline-offset: -3px;
}

.page-about .about-rule__no {
  grid-area: no;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--mint-ink);
  align-self: center;
}

.page-about .about-rule__name {
  grid-area: name;
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 700;
  color: var(--ink);
}

.page-about .about-rule__hint {
  grid-area: hint;
  font-size: 13.5px;
  line-height: 1.6;
  color: var(--graphite);
  margin-top: 4px;
}

.page-about .about-rule[open] .about-rule__hint {
  color: var(--mint-ink);
}

.page-about .about-rule__body {
  padding: 16px 22px 20px;
  border-top: 1px solid var(--line);
}

.page-about .about-rule__body p {
  margin: 0;
  font-size: 15px;
  line-height: 1.95;
  color: var(--graphite);
}

/* ---------- 05 同行的人 ---------- */

.page-about .about-together__grid {
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius-card);
  overflow: hidden;
}

@media (min-width: 760px) {
  .page-about .about-together__grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

.page-about .about-together__stat {
  padding: clamp(22px, 3vw, 34px);
  background: var(--white);
}

.page-about .about-together__value {
  margin: 0 0 8px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(28px, 4.4vw, 38px);
  letter-spacing: -0.02em;
  line-height: 1.05;
  color: var(--ink);
}

.page-about .about-together__value .num {
  font-family: var(--font-mono);
  font-weight: 700;
  color: var(--mint-ink);
  margin-right: 2px;
}

.page-about .about-together__label {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--graphite);
}

.page-about .about-together__note {
  margin-top: clamp(28px, 4vw, 44px);
  display: grid;
  gap: 20px;
}

@media (min-width: 820px) {
  .page-about .about-together__note {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    gap: 32px;
  }
}

.page-about .about-together__note p {
  margin: 0;
  font-size: 16.5px;
  line-height: 1.95;
  color: var(--ink);
  max-width: 54ch;
}

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

/* ---------- 窄屏兜底 ---------- */

@media (max-width: 600px) {
  .page-about .about-hero__metrics li {
    padding: 0 8px;
  }
  .page-about .about-hero__metrics .m-label {
    font-size: 12px;
  }
  .page-about .about-rule summary {
    padding: 16px 16px;
  }
  .page-about .about-rule__body {
    padding: 14px 16px 18px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-team__card {
    transition: none;
  }
  .page-about .about-team__card:hover {
    transform: none;
  }
}