.page-about {
  --about-rule: 1px solid var(--mist);
  --about-num-size: clamp(3rem, 8vw, 7rem);
  background: var(--paper);
  color: var(--ink);
  font-family: var(--font-sans);
  overflow-x: hidden;
}

/* ===== 章节索引（宽屏侧边） ===== */
.page-about .about-toc {
  display: none;
}

@media (min-width: 1420px) {
  .page-about .about-toc {
    display: block;
    position: fixed;
    right: 1.4rem;
    top: 50%;
    transform: translateY(-50%);
    z-index: 4;
    padding: 1rem 0.9rem;
    border-left: 1px solid var(--mist);
    background: color-mix(in srgb, var(--paper) 82%, transparent);
  }
}

.page-about .about-toc__link {
  display: block;
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  color: var(--mist);
  text-decoration: none;
  padding: 0.34rem 0;
  transition: color 0.25s ease, transform 0.25s ease;
}

.page-about .about-toc__link:hover,
.page-about .about-toc__link:focus-visible {
  color: var(--ice-700);
  transform: translateX(-3px);
  outline: 2px solid var(--ice-500);
  outline-offset: 2px;
}

/* ===== 首屏 ===== */
.page-about .about-open {
  position: relative;
  overflow: hidden;
  padding: clamp(1.25rem, 3.5vw, 2.25rem) 0 clamp(2.5rem, 6vw, 4.5rem);
  border-bottom: var(--about-rule);
  background: linear-gradient(180deg, var(--paper) 0%, var(--paper) 52%, var(--ice-100) 100%);
}

.page-about .about-open::before {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(var(--ice-100) 1px, transparent 1px),
    linear-gradient(90deg, var(--ice-100) 1px, transparent 1px);
  background-size: 46px 46px;
  opacity: 0.55;
  -webkit-mask-image: linear-gradient(to bottom, rgba(0, 0, 0, 0.6), transparent 72%);
  mask-image: linear-gradient(to bottom, rgba(0, 0, 0, 0.6), transparent 72%);
  pointer-events: none;
}

.page-about .about-open .breadcrumbs {
  position: relative;
  margin-bottom: clamp(1.25rem, 3vw, 2rem);
}

.page-about .about-open__grid {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.75rem, 4vw, 3rem);
}

@media (min-width: 900px) {
  .page-about .about-open__grid {
    grid-template-columns: minmax(0, 1.65fr) minmax(0, 1fr);
    align-items: end;
  }
}

.page-about .about-open__lead h1 {
  margin: 0.6rem 0 0;
  font-size: clamp(2rem, 5.4vw, 3.7rem);
  font-weight: 900;
  line-height: 1.1;
  letter-spacing: -0.02em;
  color: var(--ice-900);
}

.page-about .about-open__dek {
  margin: 1.15rem 0 0;
  max-width: 34rem;
  font-size: 1.02rem;
  line-height: 1.85;
  color: var(--ink);
}

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

.page-about .about-open__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--mist);
  border: 1px solid var(--mist);
  box-shadow: 7px 7px 0 -2px var(--paper), 7px 7px 0 0 var(--ice-500);
}

.page-about .fact {
  background: var(--white);
  padding: 0.9rem 1rem 1rem;
}

.page-about .fact__num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(1.8rem, 3.4vw, 2.5rem);
  font-weight: 700;
  line-height: 1;
  color: var(--ice-700);
}

.page-about .fact:nth-child(2) .fact__num {
  color: var(--ember);
}

.page-about .fact__label {
  display: block;
  margin-top: 0.5rem;
  font-size: 0.78rem;
  line-height: 1.5;
  letter-spacing: 0.02em;
  color: var(--ice-700);
}

/* ===== 章节骨架 ===== */
.page-about .about-chapter {
  padding: clamp(2.25rem, 5.5vw, 4.25rem) 0;
  border-bottom: var(--about-rule);
  scroll-margin-top: 96px;
}

.page-about .about-chapter:nth-of-type(even) {
  background: linear-gradient(180deg, var(--paper), var(--white) 65%, var(--paper));
}

.page-about .about-chapter__inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1rem;
}

@media (min-width: 880px) {
  .page-about .about-chapter__inner {
    grid-template-columns: 8.5rem minmax(0, 34rem) minmax(0, 1fr);
    gap: clamp(1.5rem, 3vw, 2.5rem);
    align-items: start;
  }

  .page-about .about-chapter--wide .about-chapter__inner {
    grid-template-columns: 8.5rem minmax(0, 1fr);
  }
}

.page-about .about-chapter__mark {
  display: flex;
  align-items: flex-start;
  gap: 0.65rem;
  padding-top: 0.2rem;
}

.page-about .about-chapter__num {
  font-family: var(--font-mono);
  font-size: var(--about-num-size);
  font-weight: 700;
  line-height: 0.78;
  letter-spacing: -0.05em;
  color: var(--ice-100);
}

.page-about .about-chapter__eyebrow {
  writing-mode: vertical-rl;
  text-orientation: mixed;
  font-size: 0.7rem;
  letter-spacing: 0.3em;
  color: var(--mist);
  padding-top: 0.3rem;
}

.page-about .about-chapter__title {
  position: relative;
  margin: 0 0 1.15rem;
  padding-bottom: 0.85rem;
  font-size: clamp(1.4rem, 3vw, 2rem);
  font-weight: 800;
  line-height: 1.28;
  letter-spacing: -0.01em;
  color: var(--ice-900);
}

.page-about .about-chapter__title::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 0;
  width: 2.6rem;
  height: 3px;
  background: var(--volt-deep);
  transform: skewX(-8deg);
}

.page-about .about-chapter__body > p {
  max-width: 35rem;
  margin: 0 0 1.05em;
  font-size: 1.015rem;
  line-height: 1.9;
  color: var(--ink);
}

.page-about .about-chapter__body a {
  color: var(--ice-700);
  text-decoration: underline;
  text-underline-offset: 3px;
  text-decoration-color: var(--volt-deep);
}

/* ===== 图片 ===== */
.page-about .about-figure {
  margin: clamp(1.6rem, 4vw, 2.6rem) 0 0;
}

.page-about .about-figure .figure__media {
  overflow: hidden;
  background: var(--ice-100);
  border: 1px solid var(--mist);
  box-shadow: 9px 9px 0 -3px var(--paper), 9px 9px 0 0 var(--ice-100);
}

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

.page-about .about-figure figcaption {
  margin-top: 0.75rem;
  font-size: 0.8rem;
  line-height: 1.6;
  letter-spacing: 0.02em;
  color: var(--ice-700);
}

.page-about .about-figure--side {
  margin-top: 0.5rem;
}

/* ===== 时间线 ===== */
.page-about .about-timeline {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1rem;
  margin-top: 1.5rem;
}

@media (min-width: 800px) {
  .page-about .about-timeline {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1.1rem;
  }
}

.page-about .timeline-stop {
  position: relative;
  background: var(--white);
  border: 1px solid var(--mist);
  box-shadow: 5px 5px 0 -1px var(--paper), 5px 5px 0 0 var(--mist);
  padding: 1.15rem 1.1rem 1.2rem;
  transition: transform 0.3s ease, box-shadow 0.3s ease, border-color 0.3s ease;
}

.page-about .timeline-stop:hover,
.page-about .timeline-stop:focus {
  transform: translateY(-5px);
  border-color: var(--ice-500);
  box-shadow: 5px 5px 0 -1px var(--paper), 5px 5px 0 0 var(--ice-500);
  outline: none;
}

.page-about .timeline-stop:focus-visible {
  outline: 2px solid var(--ice-500);
  outline-offset: 3px;
}

.page-about .timeline-stop__bar {
  display: block;
  height: 4px;
  margin-bottom: 0.95rem;
  background: linear-gradient(90deg, var(--volt), var(--ice-500));
  transform: skewX(-8deg);
}

.page-about .timeline-stop:nth-child(2) .timeline-stop__bar {
  background: linear-gradient(90deg, var(--ember), var(--volt));
}

.page-about .timeline-stop:nth-child(3) .timeline-stop__bar {
  background: linear-gradient(90deg, var(--indigo), var(--ice-500));
}

.page-about .timeline-stop__stage {
  margin: 0 0 0.55rem;
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.12em;
  color: var(--volt-deep);
}

.page-about .timeline-stop__phase {
  margin: 0 0 0.6rem;
  font-size: 1.02rem;
  font-weight: 800;
  line-height: 1.45;
  color: var(--ice-900);
}

.page-about .timeline-stop__text {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.75;
  color: var(--ink);
}

.page-about .timeline-stop__more {
  max-height: 0;
  overflow: hidden;
  opacity: 0;
  margin: 0;
  font-size: 0.86rem;
  line-height: 1.7;
  color: var(--ice-700);
  transition: max-height 0.38s ease, opacity 0.32s ease, margin-top 0.32s ease;
}

.page-about .timeline-stop:hover .timeline-stop__more,
.page-about .timeline-stop:focus .timeline-stop__more,
.page-about .timeline-stop:focus-within .timeline-stop__more {
  max-height: 16rem;
  opacity: 1;
  margin-top: 0.7rem;
}

/* ===== 数据工序（深色带） ===== */
.page-about .about-flow {
  position: relative;
  overflow: hidden;
  margin-top: 1.6rem;
  padding: clamp(1.4rem, 3.5vw, 2.4rem);
  background: var(--ice-900);
  color: var(--paper);
}

.page-about .about-flow::after {
  content: "";
  position: absolute;
  top: -46px;
  right: -70px;
  width: 240px;
  height: 150px;
  background: var(--volt);
  opacity: 0.14;
  transform: rotate(-8deg);
  pointer-events: none;
}

.page-about .flow-list {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1.15rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

@media (min-width: 820px) {
  .page-about .flow-list {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 1.25rem;
  }
}

.page-about .flow-step {
  border-top: 2px solid rgba(198, 255, 61, 0.45);
  padding-top: 0.8rem;
}

.page-about .flow-step__idx {
  display: block;
  font-family: var(--font-mono);
  font-size: 1.5rem;
  font-weight: 700;
  line-height: 1;
  color: var(--volt);
}

.page-about .flow-step__name {
  margin: 0.55rem 0 0.45rem;
  font-size: 1rem;
  font-weight: 800;
  letter-spacing: 0.04em;
  color: var(--paper);
}

.page-about .flow-step__desc {
  margin: 0;
  font-size: 0.86rem;
  line-height: 1.75;
  color: var(--ice-100);
}

.page-about .about-flow__foot {
  position: relative;
  margin: 1.6rem 0 0;
  padding-top: 1rem;
  border-top: 1px solid rgba(221, 237, 247, 0.25);
  font-size: 0.82rem;
  line-height: 1.7;
  letter-spacing: 0.02em;
  color: var(--ice-100);
}

/* ===== 团队档案卡 ===== */
.page-about .team-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1rem;
  margin-top: 1.6rem;
}

@media (min-width: 680px) {
  .page-about .team-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 1080px) {
  .page-about .team-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    align-items: start;
  }

  .page-about .team-card:nth-child(2),
  .page-about .team-card:nth-child(4) {
    margin-top: 2rem;
  }
}

.page-about .team-card {
  padding: 1.15rem 1.1rem 1.25rem;
}

.page-about .team-card__name {
  margin: 0.55rem 0 0.7rem;
  font-size: 1rem;
  font-weight: 800;
  line-height: 1.45;
  color: var(--ice-900);
}

.page-about .team-card__list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .team-card__list li {
  position: relative;
  padding-left: 0.85rem;
  margin-bottom: 0.45rem;
  font-size: 0.85rem;
  line-height: 1.7;
  color: var(--ice-700);
}

.page-about .team-card__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.65em;
  width: 0.42rem;
  height: 2px;
  background: var(--volt-deep);
}

/* ===== 覆盖范围 ===== */
.page-about .about-cover__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1.6rem;
}

@media (min-width: 900px) {
  .page-about .about-cover__grid {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
    gap: 2.5rem;
    align-items: start;
  }
}

.page-about .about-cover__list > p {
  max-width: 34rem;
  margin: 0 0 1.2rem;
  font-size: 1.015rem;
  line-height: 1.9;
  color: var(--ink);
}

.page-about .cover-item {
  display: grid;
  grid-template-columns: 3.8rem minmax(0, 1fr);
  gap: 0.9rem;
  align-items: baseline;
  padding: 0.85rem 0;
  border-top: var(--about-rule);
}

.page-about .cover-item:last-child {
  border-bottom: var(--about-rule);
}

.page-about .cover-item__num {
  font-family: var(--font-mono);
  font-size: 1.45rem;
  font-weight: 700;
  line-height: 1;
  color: var(--ice-500);
}

.page-about .cover-item:nth-child(3) .cover-item__num {
  color: var(--ember);
}

.page-about .cover-item__text {
  margin: 0;
  font-size: 0.9rem;
  line-height: 1.75;
  color: var(--ink);
}

/* ===== 复盘引文 ===== */
.page-about .about-quote {
  position: relative;
  margin: 1.7rem 0 0;
  padding: 1.4rem 1.35rem 1.4rem 1.7rem;
  background: var(--white);
  border: 1px solid var(--mist);
  box-shadow: 7px 7px 0 -1px var(--paper), 7px 7px 0 0 var(--wine);
}

.page-about .about-quote::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 6px;
  background: var(--wine);
}

.page-about .about-quote p {
  margin: 0;
  font-size: 1.08rem;
  font-weight: 700;
  line-height: 1.7;
  color: var(--wine);
}

.page-about .about-quote cite {
  display: block;
  margin-top: 0.7rem;
  font-style: normal;
  font-family: var(--font-mono);
  font-size: 0.74rem;
  letter-spacing: 0.12em;
  color: var(--ice-700);
}

/* ===== 下一步 ===== */
.page-about .next-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1rem;
  margin-top: 1.6rem;
}

@media (min-width: 720px) {
  .page-about .next-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 1.25rem;
  }
}

.page-about .next-card {
  position: relative;
  display: block;
  padding: 1.35rem 3rem 1.45rem 1.25rem;
  background: var(--white);
  border: 1px solid var(--mist);
  text-decoration: none;
  transition: transform 0.26s ease, border-color 0.26s ease, box-shadow 0.26s ease;
}

.page-about .next-card:hover,
.page-about .next-card:focus-visible {
  transform: translateY(-4px);
  border-color: var(--ice-500);
  box-shadow: 0 12px 0 -8px var(--ice-100);
  outline: 2px solid var(--ice-500);
  outline-offset: 2px;
}

.page-about .next-card__tag {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  color: var(--volt-deep);
}

.page-about .next-card__title {
  display: block;
  margin-top: 0.6rem;
  font-size: 1.05rem;
  font-weight: 800;
  line-height: 1.5;
  color: var(--ice-900);
}

.page-about .next-card__arrow {
  position: absolute;
  right: 1.1rem;
  top: 50%;
  transform: translateY(-50%);
  font-family: var(--font-mono);
  font-size: 1.15rem;
  color: var(--ice-500);
  transition: transform 0.26s ease;
}

.page-about .next-card:hover .next-card__arrow,
.page-about .next-card:focus-visible .next-card__arrow {
  transform: translate(4px, -50%);
  color: var(--volt-deep);
}

/* ===== 返回顶部 ===== */
.page-about .to-top {
  position: fixed;
  right: 1rem;
  bottom: 1rem;
  z-index: 6;
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  padding: 0.6rem 0.85rem;
  background: var(--ice-900);
  color: var(--paper);
  text-decoration: none;
  border: 1px solid var(--ice-900);
  box-shadow: 4px 4px 0 0 var(--volt);
  font-size: 0.78rem;
  letter-spacing: 0.08em;
  transition: transform 0.25s ease, box-shadow 0.25s ease;
}

.page-about .to-top:hover,
.page-about .to-top:focus-visible {
  transform: translate(-2px, -2px);
  box-shadow: 6px 6px 0 0 var(--volt);
  outline: 2px solid var(--volt);
  outline-offset: 2px;
}

.page-about .to-top__arrow {
  font-family: var(--font-mono);
  color: var(--volt);
}

@media (min-width: 900px) {
  .page-about .to-top {
    right: 1.6rem;
    bottom: 1.6rem;
  }
}
<<<END>>>