.page-about {
  --about-idx-w: 176px;
  --about-sticky-top: 88px;
  display: block;
}

.page-about .about-shell {
  padding-top: 20px;
  padding-bottom: 72px;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: 28px 0 4px;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  z-index: 0;
  top: -60px;
  right: -8%;
  width: 58%;
  height: 240px;
  background: linear-gradient(118deg, rgba(0, 230, 195, 0.13), rgba(0, 230, 195, 0) 66%);
  clip-path: polygon(24% 0, 100% 0, 76% 100%, 0 100%);
  pointer-events: none;
}

.page-about .about-hero > * {
  position: relative;
  z-index: 1;
}

.page-about .about-hero__grid {
  display: grid;
  gap: 30px;
}

.page-about .about-hero__title {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(30px, 8vw, 46px);
  line-height: 1.04;
  letter-spacing: -0.012em;
  color: var(--text);
  margin: 12px 0 0;
}

.page-about .about-hero__lede {
  margin: 20px 0 0;
  max-width: 62ch;
  font-size: 17px;
  line-height: 1.9;
  color: var(--text);
}

.page-about .about-hero__sub {
  margin: 14px 0 0;
  max-width: 62ch;
  font-size: 16px;
  line-height: 1.9;
  color: var(--muted);
}

.page-about .about-hero__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  padding: 0;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-stat {
  background: var(--ink-800);
  padding: 16px 14px;
}

.page-about .about-stat dt {
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--muted);
  margin: 0;
}

.page-about .about-stat dd {
  margin: 8px 0 0;
  font-family: var(--font-data);
  font-size: 13px;
  color: var(--silver);
}

.page-about .about-stat__num {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: 34px;
  line-height: 1;
  color: var(--cyan);
  margin-right: 6px;
  vertical-align: -2px;
}

/* ---------- 索引 + 正文 ---------- */
.page-about .about-layout {
  margin-top: 40px;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 28px;
}

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

.page-about .about-index {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

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

.page-about .about-index__link {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 12px;
  background: var(--ink-900);
  color: var(--silver);
  font-size: 14px;
  line-height: 1.4;
  text-decoration: none;
  transition: background 160ms var(--ease), color 160ms var(--ease);
}

.page-about .about-index__num {
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--muted);
  transition: color 160ms var(--ease);
}

.page-about .about-index__link:hover,
.page-about .about-index__link:focus-visible {
  background: var(--ink-700);
  color: var(--text);
}

.page-about .about-index__link:hover .about-index__num,
.page-about .about-index__link:focus-visible .about-index__num {
  color: var(--cyan);
}

.page-about .about-rail__teams {
  display: none;
  margin-top: 26px;
}

.page-about .about-rail__teams-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 8px;
}

.page-about .about-rail__teams-list li {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--silver);
}

.page-about .about-rail__teams-list li::before {
  content: "";
  flex: none;
  width: 5px;
  height: 5px;
  background: var(--cyan);
  transform: rotate(45deg);
}

/* ---------- 章节通用 ---------- */
.page-about .about-section {
  padding: 34px 0;
  border-top: 1px solid var(--line);
  scroll-margin-top: 92px;
}

.page-about .about-section:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .about-section__body--split {
  margin-top: 20px;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 26px;
  align-items: start;
}

.page-about .about-note {
  margin: 24px 0 0;
  padding-left: 14px;
  border-left: 2px solid var(--mid);
  font-size: 15px;
  line-height: 1.85;
  color: var(--silver);
  max-width: 66ch;
}

.page-about .about-body .section-head__title {
  font-family: var(--font-display);
  font-weight: 700;
  letter-spacing: -0.005em;
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: 28px 0 0;
}

.page-about .about-figure .media {
  border: 1px solid var(--line);
  background: var(--ink-800);
  max-width: 100%;
}

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

.page-about .about-figure .media__caption {
  margin-top: 10px;
  font-family: var(--font-data);
  font-size: 13px;
  line-height: 1.7;
  color: var(--muted);
}

.page-about .about-figure--side {
  margin-top: 0;
}

/* ---------- 版本沿革 ---------- */
.page-about .about-versions {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
}

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

.page-about .about-version:last-child {
  padding-bottom: 0;
}

.page-about .about-version::before {
  content: "";
  position: absolute;
  left: -5px;
  top: 6px;
  width: 9px;
  height: 9px;
  background: var(--ink-900);
  border: 1px solid var(--cyan);
  transform: rotate(45deg);
}

.page-about .about-version__tag {
  display: inline-block;
  font-family: var(--font-data);
  font-size: 13px;
  letter-spacing: 0.12em;
  color: var(--cyan);
}

.page-about .about-version__tag--now {
  color: var(--text);
  background: var(--orange);
  padding: 2px 7px;
}

.page-about .about-version__name {
  margin: 8px 0 0;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 20px;
  line-height: 1.35;
  color: var(--text);
}

.page-about .about-version__issue {
  margin: 8px 0 0;
  font-family: var(--font-data);
  font-size: 13px;
  line-height: 1.6;
  color: var(--cyan);
}

.page-about .about-version__issue::before {
  content: "解决的问题 / ";
  color: var(--muted);
}

.page-about .about-version__text {
  margin: 10px 0 0;
  font-size: 16px;
  line-height: 1.9;
  color: var(--silver);
  max-width: 42ch;
}

/* ---------- 团队分工 ---------- */
.page-about .about-roster {
  margin-top: 24px;
  border-top: 1px solid var(--line);
}

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

.page-about .about-roster__head {
  display: grid;
  grid-template-columns: 28px minmax(0, 1fr) 16px;
  grid-template-areas:
    "idx name chev"
    "idx brief chev";
  gap: 4px 12px;
  align-items: center;
  padding: 16px 2px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-roster__head::marker {
  content: "";
}

.page-about .about-roster__idx {
  grid-area: idx;
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--orange);
}

.page-about .about-roster__name {
  grid-area: name;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 19px;
  line-height: 1.3;
  color: var(--text);
}

.page-about .about-roster__brief {
  grid-area: brief;
  font-size: 14px;
  line-height: 1.7;
  color: var(--muted);
}

.page-about .about-roster__chev {
  grid-area: chev;
  justify-self: end;
  width: 8px;
  height: 8px;
  border-right: 1px solid var(--cyan);
  border-bottom: 1px solid var(--cyan);
  transform: rotate(45deg) translate(-2px, -2px);
  transition: transform 160ms var(--ease);
}

.page-about .about-roster__row[open] .about-roster__chev {
  transform: rotate(-135deg) translate(-2px, -2px);
}

.page-about .about-roster__head:hover .about-roster__name,
.page-about .about-roster__head:focus-visible .about-roster__name {
  color: var(--cyan);
}

.page-about .about-roster__body {
  padding: 4px 2px 20px 40px;
}

.page-about .about-roster__body p {
  margin: 0 0 10px;
  font-size: 15px;
  line-height: 1.9;
  color: var(--silver);
  max-width: 68ch;
}

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

.page-about .about-roster__body a {
  color: var(--cyan);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ---------- 内容口径 ---------- */
.page-about .about-sources {
  margin: 24px 0 0;
  display: grid;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-sources > div {
  background: var(--ink-800);
  padding: 15px 16px;
}

.page-about .about-sources dt {
  font-family: var(--font-data);
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--cyan);
  margin: 0;
}

.page-about .about-sources dd {
  margin: 7px 0 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--silver);
  max-width: 66ch;
}

/* ---------- 更新节奏 ---------- */
.page-about .about-paper {
  position: relative;
  margin: 26px 0 0;
  padding: 22px 18px;
  background: var(--ink-800);
  border: 1px solid var(--line);
}

.page-about .about-paper::before,
.page-about .about-paper::after {
  content: "";
  position: absolute;
  inset: 0;
  border: 1px solid var(--line);
  pointer-events: none;
}

.page-about .about-paper::before {
  transform: translate(9px, 9px);
  opacity: 0.55;
}

.page-about .about-paper::after {
  transform: translate(4.5px, 4.5px);
  opacity: 0.8;
}

.page-about .about-paper > * {
  position: relative;
  z-index: 1;
}

.page-about .about-cadence {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 18px;
}

.page-about .about-cadence li + li {
  border-top: 1px solid var(--line);
  padding-top: 18px;
}

.page-about .about-cadence__key {
  display: block;
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--muted);
}

.page-about .about-cadence__val {
  display: block;
  margin-top: 6px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 21px;
  line-height: 1.25;
  color: var(--cyan);
}

.page-about .about-cadence p {
  margin: 8px 0 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--silver);
  max-width: 64ch;
}

.page-about .about-badge-row {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 12px 14px;
  margin-top: 30px;
}

.page-about .about-badge-row p {
  flex: 1 1 300px;
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--muted);
  max-width: 62ch;
}

/* ---------- 联系与反馈 ---------- */
.page-about .about-contact {
  border: 1px solid var(--line);
  background: var(--ink-800);
  padding: 20px 18px;
}

.page-about .about-contact__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .about-contact__list li {
  display: grid;
  gap: 5px;
}

.page-about .about-contact__label {
  font-family: var(--font-data);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--muted);
}

.page-about .about-contact__value {
  font-family: var(--font-data);
  font-size: 15px;
  line-height: 1.6;
  color: var(--text);
  word-break: break-word;
}

.page-about .about-contact__note {
  margin: 18px 0 0;
  padding-top: 14px;
  border-top: 1px solid var(--line);
  font-size: 14px;
  line-height: 1.8;
  color: var(--silver);
}

.page-about .about-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

/* ---------- 断点 ---------- */
@media (min-width: 640px) {
  .page-about .about-shell {
    padding-top: 28px;
    padding-bottom: 88px;
  }

  .page-about .about-stats-desktop {
    display: grid;
  }

  .page-about .about-paper {
    padding: 26px 22px;
  }

  .page-about .about-roster__body {
    padding-left: 44px;
  }
}

@media (min-width: 760px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 46px;
    align-items: end;
  }

  .page-about .about-hero__title {
    font-size: clamp(38px, 4.4vw, 58px);
  }

  .page-about .about-section__body--split {
    grid-template-columns: minmax(0, 1.65fr) minmax(0, 1fr);
    gap: 34px;
  }

  .page-about .about-figure--side {
    margin-top: 4px;
  }

  .page-about .about-versions {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 26px;
    margin-top: 30px;
  }

  .page-about .about-version {
    padding: 26px 0 0;
    border-left: 0;
    border-top: 1px dashed var(--line);
  }

  .page-about .about-version:last-child {
    padding-bottom: 0;
  }

  .page-about .about-version::before {
    top: -5px;
    left: 6px;
  }

  .page-about .about-version__text {
    max-width: none;
  }

  .page-about .about-roster__head {
    grid-template-columns: 34px max-content minmax(0, 1fr) 16px;
    grid-template-areas: "idx name brief chev";
    gap: 10px 16px;
    align-items: baseline;
    padding: 18px 2px;
  }

  .page-about .about-contact {
    padding: 24px 22px;
  }
}

@media (min-width: 1080px) {
  .page-about .about-layout {
    grid-template-columns: var(--about-idx-w) minmax(0, 1fr);
    gap: clamp(36px, 4vw, 64px);
    align-items: start;
    margin-top: 56px;
  }

  .page-about .about-rail {
    position: sticky;
    top: var(--about-sticky-top);
    align-self: start;
  }

  .page-about .about-rail__teams {
    display: block;
  }

  .page-about .about-index {
    grid-template-columns: minmax(0, 1fr);
    gap: 0;
    background: transparent;
    border: 0;
    border-left: 1px solid var(--line);
  }

  .page-about .about-index__link {
    padding: 9px 0 9px 15px;
    background: transparent;
  }

  .page-about .about-index__link::before {
    content: "";
    position: absolute;
    left: -1px;
    top: 50%;
    width: 3px;
    height: 0;
    background: var(--cyan);
    transform: translateY(-50%);
    transition: height 160ms var(--ease);
  }

  .page-about .about-index__link:hover,
  .page-about .about-index__link:focus-visible {
    background: transparent;
  }

  .page-about .about-index__link:hover::before,
  .page-about .about-index__link:focus-visible::before {
    height: 62%;
  }

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

  .page-about .about-hero__title {
    font-size: clamp(42px, 3.6vw, 62px);
  }

  .page-about .about-cadence {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 0 34px;
  }

  .page-about .about-cadence li {
    padding: 16px 0;
  }

  .page-about .about-cadence li + li {
    border-top: 0;
    padding-top: 0;
  }

  .page-about .about-cadence li:nth-child(n + 3) {
    border-top: 1px solid var(--line);
    padding-top: 16px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-index__link,
  .page-about .about-index__num,
  .page-about .about-roster__chev,
  .page-about .about-index__link::before {
    transition: none;
  }
}