.page-about {
  background: var(--ink);
  color: var(--white);
  overflow-x: hidden;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding: clamp(20px, 4vw, 44px) 0 clamp(28px, 4vw, 48px);
  background:
    radial-gradient(115% 85% at 100% 0%, rgba(37, 217, 232, 0.16), transparent 62%),
    radial-gradient(95% 80% at 0% 105%, rgba(23, 201, 100, 0.18), transparent 66%);
  isolation: isolate;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  z-index: -1;
  right: -14%;
  bottom: -34%;
  width: 78%;
  height: 78%;
  border-radius: var(--r-lg);
  background: linear-gradient(140deg, rgba(23, 201, 100, 0.26), rgba(37, 217, 232, 0.06) 52%, transparent 78%);
  transform: rotate(-8deg);
  pointer-events: none;
}

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

.page-about .about-hero__copy .eyebrow {
  margin-bottom: 14px;
  color: var(--signal);
}

.page-about .about-hero h1 {
  margin: 0 0 18px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(30px, 7.4vw, 62px);
  line-height: 1.06;
  letter-spacing: -0.01em;
  max-width: 18ch;
}

.page-about .about-hero__lede {
  margin: 0 0 26px;
  max-width: 54ch;
  color: var(--mute);
  font-size: clamp(15px, 3.4vw, 17px);
  line-height: 1.8;
}

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

.page-about .about-hero__media {
  position: relative;
  margin: 0;
  border-radius: var(--r-lg);
  overflow: hidden;
  border: 1px solid var(--line);
  background: var(--card);
}

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

.page-about .about-hero__media::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(8, 37, 31, 0.1) 0%, rgba(4, 18, 15, 0.82) 100%);
  pointer-events: none;
}

.page-about .about-hero__caption {
  position: absolute;
  left: 18px;
  bottom: 16px;
  right: 18px;
  display: flex;
  align-items: center;
  gap: 12px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--white);
}

.page-about .about-hero__mark {
  display: inline-grid;
  place-items: center;
  width: 38px;
  height: 38px;
  border-radius: 10px;
  background: var(--signal);
  color: var(--deep);
  font-weight: 700;
  font-size: 16px;
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: clamp(26px, 4vw, 42px) auto 0;
  padding: 0;
  list-style: none;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  overflow: hidden;
}

.page-about .about-stats__item {
  background: var(--card);
  padding: 16px 14px;
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.page-about .about-stats__num {
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: clamp(24px, 6vw, 34px);
  line-height: 1;
  color: var(--cyan);
}

.page-about .about-stats__num em {
  font-style: normal;
  font-size: 0.5em;
  color: var(--mute);
  margin-left: 2px;
}

.page-about .about-stats__label {
  font-size: 13px;
  color: var(--mute);
}

/* ---------- 长卷主体 ---------- */
.page-about .about-body {
  display: grid;
  gap: clamp(26px, 4vw, 44px);
  padding-block: clamp(34px, 6vw, 64px);
}

.page-about .about-index {
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: var(--char);
  padding: 16px;
}

.page-about .about-index__title {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--mute);
  text-transform: uppercase;
}

.page-about .about-index .chapter-nav__list {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-index__no {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--cyan);
  margin-right: 8px;
}

.page-about .about-flow {
  display: grid;
  gap: clamp(34px, 6vw, 64px);
  min-width: 0;
}

.page-about .about-chapter {
  padding-top: 8px;
}

.page-about .about-chapter__eyebrow {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--amber);
}

.page-about .about-chapter__title {
  margin: 0 0 14px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(24px, 5.4vw, 40px);
  line-height: 1.14;
  max-width: 22ch;
}

.page-about .about-chapter__lede {
  margin: 0 0 24px;
  max-width: 62ch;
  color: var(--mute);
  line-height: 1.85;
  font-size: 15px;
}

.page-about .about-chapter__note {
  margin: 20px 0 0;
  font-size: 14px;
  color: var(--mute);
}

.page-about .about-chapter__note a {
  color: var(--signal);
  text-decoration: underline;
  text-underline-offset: 4px;
}

/* 三段流程 */
.page-about .flow-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 2px;
}

.page-about .flow-list__item {
  position: relative;
  padding: 20px 18px 20px 22px;
  background: var(--card);
  border-left: 3px solid var(--line);
}

.page-about .flow-list__item:nth-child(1) {
  border-left-color: var(--signal);
  border-radius: var(--r-md) var(--r-md) 0 0;
}

.page-about .flow-list__item:nth-child(2) {
  border-left-color: var(--cyan);
}

.page-about .flow-list__item:nth-child(3) {
  border-left-color: var(--amber);
  border-radius: 0 0 var(--r-md) var(--r-md);
}

.page-about .flow-list__tag {
  margin-bottom: 10px;
}

.page-about .flow-list__title {
  margin: 0 0 8px;
  font-size: 18px;
  font-weight: 700;
  line-height: 1.4;
}

.page-about .flow-list__item p {
  margin: 0;
  color: var(--mute);
  font-size: 14.5px;
  line-height: 1.8;
}

/* ---------- 类别 ---------- */
.page-about .coverage-grid {
  display: grid;
  gap: 22px;
}

.page-about .cat-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  overflow: hidden;
}

.page-about .cat-list__item {
  display: grid;
  grid-template-columns: 34px minmax(0, 1fr);
  gap: 4px 12px;
  align-items: start;
  padding: 16px 16px 18px;
  background: var(--card);
}

.page-about .cat-list__item .tag {
  grid-column: 2;
  justify-self: start;
  margin-top: 8px;
}

.page-about .cat-list__no {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--cyan);
  padding-top: 3px;
}

.page-about .cat-list__body {
  min-width: 0;
}

.page-about .cat-list__name {
  margin: 0 0 6px;
  font-size: 17px;
  font-weight: 700;
}

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

.page-about .coverage-figure,
.page-about .timeline-figure {
  margin: 0;
  border-radius: var(--r-lg);
  overflow: hidden;
  background: var(--card);
  border: 1px solid var(--line);
}

.page-about .coverage-figure img,
.page-about .timeline-figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}

.page-about .coverage-figure figcaption,
.page-about .timeline-figure figcaption {
  padding: 12px 16px 14px;
  font-size: 13px;
  color: var(--mute);
  line-height: 1.7;
}

/* ---------- 编号 ---------- */
.page-about .code-figure {
  border-radius: var(--r-lg);
  border: 1px dashed var(--line);
  background: linear-gradient(135deg, rgba(37, 217, 232, 0.1), rgba(23, 201, 100, 0.05) 60%, transparent);
  padding: 20px 18px;
  margin-bottom: 22px;
}

.page-about .code-figure__label {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--mute);
}

.page-about .code-figure__value {
  margin: 0 0 12px;
  font-family: var(--font-mono);
  font-weight: 600;
  font-size: clamp(22px, 6vw, 34px);
  letter-spacing: 0.06em;
  color: var(--signal);
  word-break: break-word;
}

.page-about .code-figure__parts {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .code-figure__part {
  font-family: var(--font-mono);
  font-size: 11px;
  padding: 4px 10px;
  border-radius: var(--r-pill);
  border: 1px solid var(--line);
  color: var(--cyan);
  background: rgba(21, 43, 37, 0.7);
}

.page-about .number-points {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 16px;
}

.page-about .number-points__item {
  padding: 16px 18px;
  border-radius: var(--r-md);
  background: var(--card);
  border: 1px solid var(--line);
}

.page-about .number-points__item h3 {
  margin: 0 0 6px;
  font-size: 16px;
  font-weight: 700;
  color: var(--white);
}

.page-about .number-points__item p {
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--mute);
}

/* ---------- 团队 ---------- */
.page-about .team-bar {
  display: flex;
  height: 46px;
  border-radius: var(--r-pill);
  overflow: hidden;
  margin-bottom: 8px;
  border: 1px solid var(--line);
}

.page-about .team-bar__seg {
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.04em;
  color: var(--deep);
  overflow: hidden;
  white-space: nowrap;
}

.page-about .team-bar__seg--edit {
  flex: 18;
  background: var(--signal);
}

.page-about .team-bar__seg--check {
  flex: 6;
  background: var(--cyan);
}

.page-about .team-bar__seg--tech {
  flex: 8;
  background: var(--amber);
}

.page-about .team-bar__seg span {
  padding: 0 6px;
  text-overflow: ellipsis;
  overflow: hidden;
}

.page-about .team-notes {
  display: grid;
  gap: 14px;
  margin-top: 20px;
}

.page-about .team-notes__col {
  padding-left: 14px;
  border-left: 2px solid var(--line);
}

.page-about .team-notes__col h3 {
  margin: 0 0 6px;
  font-size: 15px;
  font-weight: 700;
  color: var(--cyan);
}

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

.page-about .rhythm {
  margin-top: 24px;
  padding: 18px;
  border-radius: var(--r-md);
  background: var(--char);
  border: 1px solid var(--line);
}

.page-about .rhythm__label {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--amber);
}

.page-about .rhythm__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .rhythm__list li {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 12px;
  align-items: baseline;
  padding-bottom: 10px;
  border-bottom: 1px dashed var(--line);
}

.page-about .rhythm__list li:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}

.page-about .rhythm__k {
  font-family: var(--font-mono);
  font-size: 13px;
  color: var(--white);
  min-width: 7.5em;
}

.page-about .rhythm__v {
  font-size: 14px;
  color: var(--mute);
}

/* ---------- 时间线 ---------- */
.page-about .about-time {
  list-style: none;
  margin: 0 0 26px;
  padding: 0 0 0 18px;
  border-left: 1px solid var(--line);
  display: grid;
  gap: 22px;
}

.page-about .about-time__item {
  position: relative;
}

.page-about .about-time__item::before {
  content: "";
  position: absolute;
  left: -23px;
  top: 6px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--signal);
  box-shadow: 0 0 0 4px rgba(23, 201, 100, 0.16);
}

.page-about .about-time__item:nth-child(4)::before,
.page-about .about-time__item:nth-child(5)::before {
  background: var(--cyan);
  box-shadow: 0 0 0 4px rgba(37, 217, 232, 0.16);
}

.page-about .about-time__item:nth-child(6)::before {
  background: var(--amber);
  box-shadow: 0 0 0 4px rgba(255, 176, 32, 0.18);
}

.page-about .about-time__year {
  display: block;
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 600;
  color: var(--white);
  letter-spacing: 0.08em;
  margin-bottom: 6px;
}

.page-about .about-time__body h3 {
  margin: 0 0 6px;
  font-size: 16px;
  font-weight: 700;
}

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

/* ---------- 合作 ---------- */
.page-about .partner-grid {
  display: grid;
  gap: 16px;
  margin-bottom: 6px;
}

.page-about .partner-card {
  padding: 20px 18px;
  border-radius: var(--r-md);
  background: var(--card);
  border: 1px solid var(--line);
  border-top: 3px solid var(--signal);
}

.page-about .partner-card:nth-child(2) {
  border-top-color: var(--cyan);
}

.page-about .partner-card:nth-child(3) {
  border-top-color: var(--amber);
}

.page-about .partner-card__num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: clamp(30px, 8vw, 42px);
  font-weight: 600;
  line-height: 1;
  color: var(--white);
}

.page-about .partner-card__title {
  margin: 6px 0 10px;
  font-size: 14px;
  font-weight: 500;
  color: var(--mute);
}

.page-about .partner-card p:last-child {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--mute);
}

/* ---------- 收尾 ---------- */
.page-about .about-cta {
  border-radius: var(--r-lg);
  padding: clamp(24px, 5vw, 40px);
  background:
    radial-gradient(120% 120% at 100% 0%, rgba(37, 217, 232, 0.2), transparent 58%),
    linear-gradient(150deg, var(--card-hi), var(--card) 65%);
  border: 1px solid var(--line);
}

.page-about .about-cta__eyebrow {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--amber);
}

.page-about .about-cta h2 {
  margin: 0 0 12px;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(24px, 5.6vw, 36px);
  line-height: 1.15;
}

.page-about .about-cta p {
  margin: 0 0 22px;
  max-width: 52ch;
  font-size: 15px;
  line-height: 1.85;
  color: var(--mute);
}

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

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .about-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

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

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

  .page-about .cat-list__item {
    grid-template-columns: 40px minmax(0, 1fr) auto;
    align-items: center;
    padding: 18px 20px;
  }

  .page-about .cat-list__item .tag {
    grid-column: 3;
    margin-top: 0;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__inner {
    grid-template-columns: minmax(0, 1.02fr) minmax(0, 0.98fr);
    gap: clamp(32px, 4vw, 60px);
  }

  .page-about .about-hero__media {
    transform: translateY(-8px);
  }

  .page-about .about-body {
    grid-template-columns: 196px minmax(0, 1fr);
    gap: clamp(30px, 4vw, 56px);
  }

  .page-about .about-index {
    position: sticky;
    top: calc(var(--head-h) + 20px);
    align-self: start;
    padding: 18px 16px;
  }

  .page-about .about-index .chapter-nav__list {
    flex-direction: column;
    flex-wrap: nowrap;
    gap: 4px;
  }

  .page-about .about-index .chapter-nav__link {
    display: block;
    padding: 8px 10px;
    border-radius: var(--r-pill);
    font-size: 13px;
    color: var(--mute);
    text-decoration: none;
    transition: background 0.22s var(--ease), color 0.22s var(--ease);
  }

  .page-about .about-index .chapter-nav__link:hover,
  .page-about .about-index .chapter-nav__link:focus-visible {
    background: rgba(37, 217, 232, 0.12);
    color: var(--white);
  }

  .page-about .about-index .chapter-nav__link[aria-current="true"] {
    background: var(--signal);
    color: var(--deep);
    font-weight: 700;
  }

  .page-about .about-index .chapter-nav__link[aria-current="true"] .about-index__no {
    color: var(--deep);
  }

  .page-about .coverage-grid {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    align-items: start;
    gap: 26px;
  }

  .page-about .coverage-figure {
    position: sticky;
    top: calc(var(--head-h) + 24px);
  }

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

  .page-about .about-time {
    gap: 26px;
    padding-left: 24px;
  }

  .page-about .about-time__item::before {
    left: -29px;
  }

  .page-about .about-time__item {
    display: grid;
    grid-template-columns: 88px minmax(0, 1fr);
    gap: 0 18px;
    align-items: start;
  }

  .page-about .about-time__year {
    text-align: right;
    margin-bottom: 0;
    font-size: 17px;
  }
}

@media (min-width: 1120px) {
  .page-about .about-hero h1 {
    letter-spacing: -0.015em;
  }

  .page-about .about-body {
    grid-template-columns: 210px minmax(0, 1fr);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-index .chapter-nav__link {
    transition: none;
  }

  .page-about .about-hero__media {
    transform: none;
  }
}