.page-about {
  --about-rule: 1px solid rgba(176, 123, 60, 0.28);
  --about-rule-strong: 1px solid rgba(176, 123, 60, 0.45);
  background-color: var(--cream-100);
  background-image: radial-gradient(circle at 88% 4%, rgba(217, 165, 102, 0.16), transparent 42%);
  color: var(--brown-900);
  font-family: var(--font-body);
  padding-bottom: clamp(3rem, 7vw, 6rem);
}

.page-about .about-frame {
  max-width: var(--wrap);
  margin-inline: auto;
  padding-inline: var(--gutter);
}

/* ---------- 左侧刻度 ---------- */
.page-about .about-rail {
  padding-block: 1.1rem 1.2rem;
  border-bottom: var(--about-rule);
}

.page-about .about-rail__label {
  margin: 0 0 0.55rem;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.14em;
  color: var(--sage-500);
}

.page-about .about-rail__list {
  display: flex;
  gap: 0.4rem;
  margin: 0;
  padding: 0 0 0.2rem;
  list-style: none;
  overflow-x: auto;
}

.page-about .about-rail__link {
  display: inline-flex;
  align-items: baseline;
  gap: 0.35rem;
  padding: 0.42rem 0.6rem;
  border: var(--about-rule);
  color: var(--ink-700);
  font-size: 0.86rem;
  text-decoration: none;
  white-space: nowrap;
  transition: border-color var(--dur-fast) var(--ease), background-color var(--dur-fast) var(--ease);
}

.page-about .about-rail__link:hover,
.page-about .about-rail__link:focus-visible {
  border-color: var(--copper-500);
  background-color: var(--paper-50);
}

.page-about .about-rail__link:focus-visible {
  outline: 2px solid var(--copper-300);
  outline-offset: 2px;
}

.page-about .about-rail__num {
  font-family: var(--font-mono);
  font-size: 0.7rem;
  color: var(--copper-500);
}

.page-about .about-rail__version {
  display: none;
  margin-top: 1.1rem;
  padding-top: 0.9rem;
  border-top: var(--about-rule);
}

.page-about .about-rail__version-k {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.1em;
  color: var(--sage-500);
}

.page-about .about-rail__version-v {
  display: block;
  margin: 0.15rem 0 0.55rem;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.3rem;
  color: var(--ink-900);
}

/* ---------- 首屏 ---------- */
.page-about .about-crumb {
  margin: 1.15rem 0 0;
}

.page-about .about-hero {
  padding-block: clamp(1.1rem, 3vw, 2.2rem) clamp(1.8rem, 4vw, 3rem);
  border-bottom: var(--about-rule);
}

.page-about .about-hero .eyebrow {
  display: inline-block;
  margin: 0 0 0.85rem;
  padding-bottom: 0.35rem;
  border-bottom: 3px solid var(--copper-500);
  color: var(--ink-500);
}

.page-about .about-hero h1 {
  margin: 0 0 1rem;
  max-width: 22ch;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(2rem, 5.4vw, 3.4rem);
  line-height: 1.12;
  letter-spacing: -0.02em;
  color: var(--ink-900);
}

.page-about .about-hero__lede {
  max-width: 40rem;
  margin: 0;
  font-size: clamp(1rem, 1.4vw, 1.1rem);
  line-height: 1.85;
  color: var(--ink-700);
}

.page-about .about-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.9rem 1rem;
  margin: 1.75rem 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-facts li {
  padding-top: 0.6rem;
  border-top: 2px solid var(--copper-500);
}

.page-about .about-facts__k {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  letter-spacing: 0.1em;
  color: var(--sage-500);
}

.page-about .about-facts__v {
  display: block;
  margin-top: 0.25rem;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.02rem;
  color: var(--ink-900);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.7rem;
  margin-top: 1.6rem;
}

/* ---------- 章节 ---------- */
.page-about .chapter {
  padding-block: clamp(2.2rem, 4.6vw, 3.5rem);
  border-bottom: var(--about-rule);
}

.page-about .chapter__no {
  margin: 0 0 0.4rem;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.12em;
  color: var(--copper-500);
}

.page-about .chapter h2 {
  margin: 0 0 1rem;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.45rem, 3vw, 2.05rem);
  line-height: 1.28;
  letter-spacing: -0.01em;
  color: var(--ink-900);
}

.page-about .chapter__body {
  max-width: 40rem;
}

.page-about .chapter__body p {
  margin: 0 0 0.95rem;
  font-size: 1rem;
  line-height: 1.85;
  color: var(--ink-700);
}

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

.page-about .chapter--narrow .chapter__body {
  max-width: 36rem;
}

.page-about .about-note {
  margin: 1.35rem 0 0;
  padding-left: 0.9rem;
  border-left: 3px solid var(--copper-300);
  font-size: 0.92rem;
  line-height: 1.7;
  color: var(--sage-500);
}

/* ---------- 双栏错位 ---------- */
.page-about .about-split {
  display: grid;
  gap: 1.6rem;
}

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

/* ---------- 档案卡 ---------- */
.page-about .dossier {
  margin-top: 1.5rem;
  padding: 1.1rem 1.15rem 1.2rem;
  border: var(--about-rule);
  border-top: 3px solid var(--copper-500);
  background-color: var(--paper-50);
  background-image: linear-gradient(180deg, rgba(217, 165, 102, 0.1), transparent 60%);
}

.page-about .dossier__title {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.12em;
  color: var(--copper-500);
}

.page-about .about-list {
  display: grid;
  gap: 0.5rem;
  margin: 0.7rem 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-list li {
  position: relative;
  padding-left: 1.1rem;
  font-size: 0.94rem;
  line-height: 1.72;
  color: var(--ink-700);
}

.page-about .about-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 0.5rem;
  height: 1px;
  background-color: var(--copper-500);
}

/* ---------- 团队手风琴 ---------- */
.page-about .about-acc {
  margin-top: 1.3rem;
  border-top: var(--about-rule);
}

.page-about .about-acc details {
  border-bottom: var(--about-rule);
}

.page-about .about-acc summary {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.85rem 0.15rem;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.02rem;
  color: var(--ink-900);
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-acc summary::after {
  content: "+";
  font-family: var(--font-mono);
  font-size: 1.1rem;
  color: var(--copper-500);
}

.page-about .about-acc details[open] summary::after {
  content: "−";
}

.page-about .about-acc summary:focus-visible {
  outline: 2px solid var(--copper-300);
  outline-offset: 3px;
}

.page-about .about-acc__body {
  padding: 0 0.15rem 1rem;
}

.page-about .about-acc__body .about-list {
  margin-top: 0;
}

/* ---------- 图片 ---------- */
.page-about .about-figure {
  margin: 1.4rem 0 0;
}

.page-about .about-figure--banner {
  margin: 1.3rem 0 1.6rem;
}

.page-about .media-frame {
  margin: 0;
  aspect-ratio: auto;
}

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

.page-about .media-frame__caption {
  margin-top: 0.55rem;
  font-size: 0.82rem;
  line-height: 1.6;
  color: var(--sage-500);
}

/* ---------- 大字号声明 ---------- */
.page-about .about-statement {
  position: relative;
  margin-block: clamp(2rem, 4vw, 3rem);
  padding: clamp(1.5rem, 3.4vw, 2.5rem) clamp(1.3rem, 3vw, 2.4rem);
  background-color: var(--ink-900);
  background-image: linear-gradient(120deg, var(--ink-900) 0%, var(--ink-700) 100%);
  color: var(--cream-100);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.28rem, 2.7vw, 1.95rem);
  line-height: 1.42;
  letter-spacing: -0.01em;
  clip-path: polygon(0 0, calc(100% - 22px) 0, 100% 22px, 100% 100%, 22px 100%, 0 calc(100% - 22px));
}

.page-about .about-statement::before {
  content: "";
  position: absolute;
  inset: 0 auto 0 0;
  width: 3px;
  background-color: var(--copper-500);
}

.page-about .about-statement span {
  display: block;
  margin-top: 0.55rem;
  color: var(--copper-300);
  font-weight: 400;
}

/* ---------- 时间线 ---------- */
.page-about .about-timeline {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-timeline li {
  position: relative;
  display: grid;
  grid-template-columns: 3.4rem minmax(0, 1fr);
  gap: 0.9rem;
  padding: 1rem 0 1rem 1rem;
  border-left: 1px solid rgba(176, 123, 60, 0.4);
}

.page-about .about-timeline li::before {
  content: "";
  position: absolute;
  left: -4px;
  top: 1.55rem;
  width: 7px;
  height: 7px;
  background-color: var(--copper-500);
}

.page-about .about-timeline__year {
  font-family: var(--font-mono);
  font-size: 0.95rem;
  color: var(--copper-500);
}

.page-about .about-timeline h3 {
  margin: 0 0 0.35rem;
  font-family: var(--font-display);
  font-size: 1.02rem;
  font-weight: 700;
  color: var(--ink-900);
}

.page-about .about-timeline p {
  margin: 0;
  font-size: 0.94rem;
  line-height: 1.75;
  color: var(--ink-700);
}

/* ---------- 标签分组 ---------- */
.page-about .about-labels {
  display: grid;
  gap: 0.85rem;
  margin-top: 1.3rem;
}

.page-about .about-label-group {
  padding: 1rem 1.05rem 1.1rem;
  border: var(--about-rule);
  background-color: var(--paper-50);
}

.page-about .about-label-group__bar {
  display: block;
  width: 34px;
  height: 4px;
  margin-bottom: 0.6rem;
  background-color: var(--ink-500);
}

.page-about .about-label-group--rule .about-label-group__bar {
  background-color: var(--copper-500);
}

.page-about .about-label-group--device .about-label-group__bar {
  background-color: var(--sage-500);
}

.page-about .about-label-group--update .about-label-group__bar {
  background-color: var(--cinnabar);
}

.page-about .about-label-group h3 {
  margin: 0 0 0.35rem;
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 700;
  color: var(--ink-900);
}

.page-about .about-label-group p {
  margin: 0;
  font-size: 0.92rem;
  line-height: 1.72;
  color: var(--ink-700);
}

/* ---------- 幕布分隔 ---------- */
.page-about .about-curtain {
  height: 26px;
  border-block: var(--about-rule);
  background-color: var(--ink-900);
  background-image: repeating-linear-gradient(
    90deg,
    rgba(217, 165, 102, 0.28) 0 1px,
    rgba(11, 36, 31, 0) 1px 7px
  );
}

/* ---------- 复制条 ---------- */
.page-about .about-copybar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.7rem;
  margin-top: 1.4rem;
  padding: 0.85rem 1rem;
  border-left: 3px solid var(--copper-500);
  background-color: var(--beige-200);
}

.page-about .about-copybar__text {
  font-family: var(--font-mono);
  font-size: 0.88rem;
  color: var(--ink-900);
}

.page-about .about-copybar__status {
  font-size: 0.82rem;
  color: var(--ink-500);
}

.page-about .about-copybar .btn {
  padding: 0.5rem 0.9rem;
  font-size: 0.85rem;
}

/* ---------- 使用场景 ---------- */
.page-about .about-scope {
  display: grid;
  gap: 0.85rem;
  margin-top: 1.4rem;
}

.page-about .about-scope__card {
  padding: 1rem 1.05rem;
  border: var(--about-rule);
  border-left: 3px solid var(--ink-500);
  background-color: var(--paper-50);
}

.page-about .about-scope__card h3 {
  margin: 0 0 0.35rem;
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 700;
  color: var(--ink-900);
}

.page-about .about-scope__card p {
  margin: 0;
  font-size: 0.92rem;
  line-height: 1.72;
  color: var(--ink-700);
}

.page-about .about-stats {
  display: flex;
  flex-wrap: wrap;
  gap: 1.3rem 2.4rem;
  margin-top: 1.7rem;
  padding-top: 1.2rem;
  border-top: var(--about-rule-strong);
}

.page-about .about-stats__item {
  min-width: 8.5rem;
}

.page-about .about-stats__v {
  display: block;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.55rem;
  line-height: 1.2;
  color: var(--ink-900);
}

.page-about .about-stats__k {
  display: block;
  margin-top: 0.2rem;
  font-size: 0.82rem;
  line-height: 1.5;
  color: var(--sage-500);
}

/* ---------- 下一步 ---------- */
.page-about .about-next {
  display: grid;
  gap: 0.7rem;
  margin-top: 1.4rem;
}

.page-about .about-next__link {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 0.95rem 1.05rem;
  border-left: 3px solid var(--copper-500);
  background-color: var(--ink-900);
  color: var(--cream-100);
  text-decoration: none;
  transition: transform var(--dur-fast) var(--ease), background-color var(--dur-fast) var(--ease);
}

.page-about .about-next__link:hover,
.page-about .about-next__link:focus-visible {
  transform: translateY(-2px);
  background-color: var(--ink-700);
}

.page-about .about-next__link:focus-visible {
  outline: 2px solid var(--copper-300);
  outline-offset: 3px;
}

.page-about .about-next__link strong {
  display: block;
  font-family: var(--font-display);
  font-size: 1rem;
  font-weight: 700;
  color: var(--cream-100);
}

.page-about .about-next__link em {
  display: block;
  margin-top: 0.2rem;
  font-style: normal;
  font-size: 0.82rem;
  line-height: 1.55;
  color: var(--copper-300);
}

.page-about .about-next__arrow {
  font-family: var(--font-mono);
  font-size: 1.05rem;
  color: var(--copper-300);
}

/* ---------- 桌面 ---------- */
@media (min-width: 700px) {
  .page-about .about-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

@media (min-width: 880px) {
  .page-about .about-split {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    align-items: start;
  }

  .page-about .about-split__aside {
    margin-top: 2rem;
  }

  .page-about .about-split--media-left {
    grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.15fr);
  }

  .page-about .about-split--media-left .about-split__aside {
    margin-top: 2.4rem;
  }
}

@media (min-width: 1000px) {
  .page-about {
    padding-bottom: clamp(4rem, 6vw, 6rem);
  }

  .page-about .about-frame {
    display: grid;
    grid-template-columns: 196px minmax(0, 1fr);
    gap: clamp(1.8rem, 3.6vw, 3.6rem);
    align-items: start;
  }

  .page-about .about-rail {
    position: sticky;
    top: 5.5rem;
    align-self: start;
    padding: 1.6rem 1.2rem 1.6rem 0;
    border-bottom: 0;
    border-right: var(--about-rule);
  }

  .page-about .about-rail__list {
    flex-direction: column;
    gap: 0;
    overflow: visible;
  }

  .page-about .about-rail__link {
    border: 0;
    border-left: 2px solid transparent;
    padding: 0.42rem 0.2rem 0.42rem 0.7rem;
    font-size: 0.9rem;
  }

  .page-about .about-rail__link:hover,
  .page-about .about-rail__link:focus-visible {
    border-left-color: var(--copper-500);
    background-color: transparent;
  }

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

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

  .page-about .about-crumb {
    margin-top: 1.6rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-next__link,
  .page-about .about-rail__link {
    transition: none;
  }

  .page-about .about-next__link:hover,
  .page-about .about-next__link:focus-visible {
    transform: none;
  }
}
<<<END>>>