.page-about {
  --about-line: var(--line);
  --about-line-soft: var(--line-soft);
  display: block;
}

.page-about .breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  padding: 22px 0 6px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--mist);
}

.page-about .breadcrumb a {
  color: var(--mist);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color 160ms var(--ease), border-color 160ms var(--ease);
}

.page-about .breadcrumb a:hover,
.page-about .breadcrumb a:focus-visible {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

.page-about .breadcrumb [aria-current="page"] {
  color: var(--sand);
}

.page-about .breadcrumb__sep {
  color: var(--mist);
  opacity: 0.6;
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  padding: 10px 0 0;
}

.page-about .about-hero__inner {
  padding-left: clamp(14px, 3vw, 26px);
  border-left: 1px solid var(--about-line);
}

.page-about .about-hero h1 {
  margin: 10px 0 0;
  max-width: 20ch;
  font-family: var(--font-display);
  font-size: clamp(30px, 7vw, 58px);
  line-height: 1.12;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--heading);
}

.page-about .about-hero__lead {
  margin: 18px 0 0;
  max-width: 40ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--text);
}

.page-about .about-hero__meta {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  border-top: 1px solid var(--about-line);
  border-bottom: 1px solid var(--about-line);
  background: var(--about-line-soft);
}

.page-about .about-hero__meta li {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 12px 2px;
  background: var(--bg);
}

.page-about .about-hero__num {
  font-size: 24px;
  font-weight: 600;
  color: var(--cloud);
  min-width: 3.6em;
}

.page-about .about-hero__cap {
  font-size: 13px;
  line-height: 1.5;
  color: var(--mist);
}

.page-about .about-hero__band {
  margin-top: 26px;
}

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

.page-about .about-hero__figure img {
  width: 100%;
  height: auto;
  display: block;
  object-fit: cover;
  aspect-ratio: 16 / 6;
}

.page-about .about-hero__caption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.04em;
  color: var(--mist);
}

/* ---------- 手册骨架 ---------- */

.page-about .manual {
  display: grid;
  gap: 26px;
  margin-top: 40px;
}

.page-about .manual__index {
  border-top: 1px solid var(--about-line);
  padding-top: 12px;
}

.page-about .manual__index-title {
  margin: 0 0 10px;
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--mist);
}

.page-about .chapter-nav {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 6px 8px;
}

.page-about .chapter-nav__link {
  display: inline-flex;
  align-items: baseline;
  gap: 7px;
  padding: 6px 10px;
  font-size: 13px;
  color: var(--sand);
  text-decoration: none;
  border: 1px solid var(--about-line-soft);
  clip-path: polygon(8px 0, 100% 0, 100% 100%, 0 100%, 0 8px);
  transition: background 160ms var(--ease), border-color 160ms var(--ease), color 160ms var(--ease);
}

.page-about .chapter-nav__link .mono {
  font-size: 11px;
  color: var(--mist);
}

.page-about .chapter-nav__link:hover,
.page-about .chapter-nav__link:focus-visible {
  background: var(--surface-2);
  border-color: var(--cyan-deep);
  color: var(--cloud);
}

.page-about .chapter-nav__link:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: 2px;
}

.page-about .manual__index-note {
  margin: 14px 0 0;
  font-size: 12px;
  line-height: 1.7;
  color: var(--mist);
}

.page-about .manual__index-note a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid var(--cyan-deep);
}

.page-about .manual__body {
  min-width: 0;
}

/* ---------- 章节 ---------- */

.page-about .chapter {
  scroll-margin-top: calc(var(--cmd-h) + var(--scale-h) + 18px);
}

.page-about .chapter + .chapter {
  margin-top: 40px;
  padding-top: 34px;
  border-top: 1px solid var(--about-line);
}

.page-about .chapter__head {
  max-width: 46ch;
}

.page-about .chapter__title {
  margin: 8px 0 0;
  font-family: var(--font-display);
  font-size: clamp(22px, 4.2vw, 32px);
  line-height: 1.25;
  font-weight: 700;
  color: var(--heading);
}

.page-about .chapter__lead {
  margin: 12px 0 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--text);
}

.page-about .chapter__tools {
  margin: 18px 0 12px;
}

/* ---------- 准则卡 ---------- */

.page-about .creed-list {
  display: grid;
  gap: 10px;
}

.page-about .creed {
  background: var(--surface);
  border: 1px solid var(--about-line-soft);
  clip-path: polygon(var(--cut) 0, 100% 0, 100% calc(100% - var(--cut)), calc(100% - var(--cut)) 100%, 0 100%, 0 var(--cut));
  transition: background 160ms var(--ease), border-color 160ms var(--ease);
}

.page-about .creed:hover {
  border-color: var(--about-line);
}

.page-about .creed.is-open {
  background: var(--surface-2);
}

.page-about .creed__trigger {
  width: 100%;
  display: grid;
  grid-template-columns: auto 1fr auto;
  grid-template-areas:
    "num title sign"
    "num hint sign";
  align-items: center;
  gap: 2px 12px;
  padding: 14px 16px;
  background: none;
  border: 0;
  text-align: left;
  color: inherit;
  cursor: pointer;
  font-family: var(--font-body);
}

.page-about .creed__trigger:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: -2px;
}

.page-about .creed__num {
  grid-area: num;
  font-size: 13px;
  font-weight: 600;
  color: var(--cyan);
  padding: 2px 6px;
  border: 1px solid var(--cyan-deep);
  align-self: center;
}

.page-about .creed__title {
  grid-area: title;
  font-size: 16px;
  font-weight: 700;
  color: var(--heading);
}

.page-about .creed__hint {
  grid-area: hint;
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--mist);
}

.page-about .creed__sign {
  grid-area: sign;
  font-family: var(--font-mono);
  font-size: 20px;
  line-height: 1;
  color: var(--orange);
}

.page-about .creed__panel {
  display: none;
}

.page-about .creed.is-open .creed__panel {
  display: block;
}

.page-about .creed__inner {
  padding: 0 16px 18px;
  border-top: 1px dashed var(--about-line-soft);
  margin-top: 2px;
}

.page-about .creed__inner p {
  margin: 14px 0 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--text);
  max-width: 44ch;
}

.page-about .creed__points {
  margin: 12px 0 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 8px;
}

.page-about .creed__points li {
  position: relative;
  padding-left: 16px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--sand);
}

.page-about .creed__points li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.62em;
  width: 6px;
  height: 6px;
  background: var(--cyan);
  transform: rotate(45deg);
}

/* ---------- 团队 ---------- */

.page-about .team {
  display: grid;
  gap: 24px;
  margin-top: 22px;
}

.page-about .team__table {
  min-width: 0;
}

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

.page-about .duty__row {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 4px 14px;
  padding: 12px 0;
  border-bottom: 1px solid var(--about-line-soft);
  font-size: 13px;
  line-height: 1.7;
}

.page-about .duty__row > span:nth-child(3) {
  grid-column: 1 / -1;
}

.page-about .duty__row--head {
  font-size: 11px;
  letter-spacing: 0.12em;
  color: var(--mist);
}

.page-about .duty__row--head > span:nth-child(3) {
  display: none;
}

.page-about .duty__role {
  color: var(--heading);
  font-weight: 600;
  font-size: 14px;
}

.page-about .duty__count {
  color: var(--cyan);
  font-size: 15px;
  font-weight: 600;
}

.page-about .duty__desc {
  color: var(--text);
}

.page-about .rhythm {
  list-style: none;
  margin: 20px 0 0;
  padding: 0;
  display: grid;
  gap: 1px;
  background: var(--about-line-soft);
  border: 1px solid var(--about-line-soft);
}

.page-about .rhythm__item {
  display: grid;
  grid-template-columns: 56px 1fr;
  gap: 10px;
  align-items: start;
  padding: 12px 14px;
  background: var(--bg);
}

.page-about .rhythm__idx {
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--orange);
  padding-top: 3px;
}

.page-about .rhythm__text {
  margin: 0;
  font-size: 13px;
  line-height: 1.7;
  color: var(--sand);
}

.page-about .team__figure {
  margin: 0;
  align-self: start;
}

.page-about .team__figure img {
  width: 100%;
  height: auto;
  display: block;
  object-fit: cover;
  aspect-ratio: 10 / 7;
}

.page-about .team__caption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.04em;
  color: var(--mist);
}

/* ---------- 演进轨道 ---------- */

.page-about .track {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  gap: 0;
}

.page-about .track__item {
  position: relative;
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 2px 10px;
  padding: 0 0 22px 22px;
  border-left: 1px solid var(--about-line);
}

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

.page-about .track__dot {
  position: absolute;
  left: -4.5px;
  top: 7px;
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--mist);
}

.page-about .track__dot::after {
  content: "";
  position: absolute;
  inset: -5px;
  border: 1px solid var(--cyan);
  border-radius: 50%;
  opacity: 0;
  transform: scale(0.6);
  transition: opacity 160ms var(--ease), transform 160ms var(--ease);
}

.page-about .track__item:hover .track__dot::after {
  opacity: 1;
  transform: scale(1);
}

.page-about .track__dot--version {
  background: var(--orange);
}

.page-about .track__dot--content {
  background: var(--cyan);
}

.page-about .track__year {
  grid-column: 1;
  font-size: 16px;
  font-weight: 600;
  color: var(--cloud);
  letter-spacing: 0.02em;
}

.page-about .track__label {
  grid-column: 2;
  font-size: 14px;
  font-weight: 600;
  color: var(--sand);
  padding-top: 2px;
}

.page-about .track__note {
  grid-column: 2;
  font-size: 13px;
  line-height: 1.7;
  color: var(--mist);
}

/* ---------- 专题 ---------- */

.page-about .report {
  display: grid;
  gap: 22px;
  margin-top: 22px;
}

.page-about .report__figure {
  margin: 0;
  max-width: 320px;
}

.page-about .report__figure img {
  width: 100%;
  height: auto;
  display: block;
  object-fit: cover;
  aspect-ratio: 3 / 4;
}

.page-about .report__caption {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.04em;
  color: var(--mist);
}

.page-about .report__body {
  min-width: 0;
}

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

.page-about .report__issues li {
  padding: 10px 0 10px 0;
  border-bottom: 1px solid var(--about-line-soft);
  font-size: 13px;
  line-height: 1.7;
  color: var(--text);
}

.page-about .report__issue-idx {
  display: inline-block;
  margin-right: 8px;
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--cyan);
}

.page-about .report__text {
  margin: 16px 0 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--text);
  max-width: 44ch;
}

.page-about .report__links {
  margin: 18px 0 0;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

/* ---------- 服务范围 ---------- */

.page-about .scope {
  display: grid;
  gap: 14px;
  margin-top: 22px;
}

.page-about .scope__panel {
  padding: 18px 16px 16px;
  min-width: 0;
}

.page-about .scope__title {
  margin: 0 0 12px;
  font-size: 15px;
  font-weight: 700;
  color: var(--heading);
  padding-bottom: 10px;
  border-bottom: 1px solid var(--about-line-soft);
}

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

.page-about .scope__list li {
  position: relative;
  padding-left: 16px;
  font-size: 13px;
  line-height: 1.75;
  color: var(--text);
}

.page-about .scope__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.62em;
  width: 6px;
  height: 6px;
  rotate: 45deg;
}

.page-about .scope__panel--in .scope__list li::before {
  background: var(--cyan);
}

.page-about .scope__panel--out .scope__list li::before {
  background: var(--mist);
}

.page-about .scope__foot {
  margin: 14px 0 0;
  padding-top: 12px;
  border-top: 1px dashed var(--about-line-soft);
  font-size: 12px;
  line-height: 1.7;
  color: var(--mist);
}

.page-about .scope__foot a {
  color: var(--orange);
  text-decoration: none;
  border-bottom: 1px solid var(--orange-deep);
}

/* ---------- 底部通道 ---------- */

.page-about .about-cta {
  margin-top: 56px;
  padding: 34px 0 52px;
  background: var(--surface);
  border-top: 1px solid var(--about-line);
}

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

.page-about .about-cta__title {
  margin: 8px 0 0;
  font-family: var(--font-display);
  font-size: clamp(20px, 4vw, 28px);
  line-height: 1.3;
  font-weight: 700;
  color: var(--heading);
  max-width: 26ch;
}

.page-about .about-cta__grid {
  display: grid;
  gap: 1px;
  background: var(--about-line-soft);
  border: 1px solid var(--about-line-soft);
}

.page-about .about-cta__gate {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 12px;
  padding: 14px 16px;
  background: var(--navy-900);
  color: var(--sand);
  text-decoration: none;
  font-size: 14px;
  transition: background 160ms var(--ease), color 160ms var(--ease);
}

.page-about .about-cta__gate:hover,
.page-about .about-cta__gate:focus-visible {
  background: var(--surface-2);
  color: var(--cloud);
}

.page-about .about-cta__gate:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: -2px;
}

.page-about .about-cta__gate-idx {
  font-size: 11px;
  color: var(--mist);
}

.page-about .about-cta__gate-arrow {
  font-family: var(--font-mono);
  color: var(--orange);
  transition: transform 160ms var(--ease);
}

.page-about .about-cta__gate:hover .about-cta__gate-arrow {
  transform: translateX(4px);
}

/* ---------- 断点 ---------- */

@media (min-width: 600px) {
  .page-about .about-hero__meta {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-hero__meta li {
    flex-direction: column;
    gap: 4px;
    padding: 14px 12px 14px 0;
  }

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

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

@media (min-width: 900px) {
  .page-about .manual {
    grid-template-columns: 200px minmax(0, 1fr);
    gap: 48px;
  }

  .page-about .manual__index {
    position: sticky;
    top: calc(var(--cmd-h) + var(--scale-h) + 22px);
  }

  .page-about .chapter-nav {
    flex-direction: column;
    flex-wrap: nowrap;
  }

  .page-about .chapter-nav__link {
    width: 100%;
    border-color: transparent;
    border-left: 2px solid transparent;
    clip-path: none;
    padding: 7px 8px;
  }

  .page-about .chapter-nav__link:hover,
  .page-about .chapter-nav__link:focus-visible {
    border-left-color: var(--cyan);
  }

  .page-about .about-hero__lead {
    font-size: 16px;
  }

  .page-about .team {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    gap: 32px;
  }

  .page-about .duty__row {
    grid-template-columns: 132px 44px minmax(0, 1fr);
    align-items: baseline;
    font-size: 13px;
  }

  .page-about .duty__row > span:nth-child(3) {
    grid-column: auto;
  }

  .page-about .duty__row--head > span:nth-child(3) {
    display: block;
  }

  .page-about .report {
    grid-template-columns: minmax(0, 0.7fr) minmax(0, 1.3fr);
    gap: 34px;
    align-items: start;
  }

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

  .page-about .track {
    grid-template-columns: repeat(5, minmax(0, 1fr));
    margin-top: 34px;
  }

  .page-about .track__item {
    grid-template-columns: 1fr;
    padding: 24px 16px 0 0;
    border-left: 0;
    border-top: 1px solid var(--about-line);
  }

  .page-about .track__dot {
    left: 0;
    top: -4.5px;
  }

  .page-about .track__year {
    grid-column: 1;
  }

  .page-about .track__label {
    grid-column: 1;
    padding-top: 4px;
  }

  .page-about .track__note {
    grid-column: 1;
  }

  .page-about .about-cta__inner {
    grid-template-columns: minmax(0, 0.8fr) minmax(0, 1.2fr);
    align-items: start;
    gap: 32px;
  }
}

@media (min-width: 1100px) {
  .page-about .manual {
    grid-template-columns: 220px minmax(0, 1fr);
  }

  .page-about .creed__trigger {
    grid-template-columns: auto 1fr 150px auto;
    grid-template-areas: "num title hint sign";
    padding: 16px 18px;
  }

  .page-about .creed__inner {
    padding: 0 18px 20px;
  }
}
<<<END>>>