.page-about {
  background: var(--ink-900);
  color: var(--text);
  padding-bottom: clamp(56px, 9vw, 104px);
}

.page-about .container {
  padding-top: clamp(16px, 3vw, 28px);
}

/* ---------- 布局：左年份索引 + 右长文 ---------- */
.page-about .about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(24px, 4vw, 48px);
  margin-top: clamp(16px, 2.5vw, 24px);
}

@media (min-width: 1024px) {
  .page-about .about-layout {
    grid-template-columns: 150px minmax(0, 1fr);
    gap: clamp(32px, 4vw, 64px);
  }
}

.page-about .about-index__title {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--stone);
}

.page-about .about-index__list {
  list-style: none;
  margin: 10px 0 0;
  padding: 0;
  display: flex;
  gap: 4px;
  overflow-x: auto;
  scrollbar-width: none;
}

.page-about .about-index__list::-webkit-scrollbar {
  display: none;
}

.page-about .about-index__list a {
  display: block;
  padding: 8px 12px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--stone);
  text-decoration: none;
  white-space: nowrap;
  border-left: 2px solid transparent;
  transition: color 0.2s var(--ease), border-color 0.2s var(--ease), background 0.2s var(--ease);
}

.page-about .about-index__list a:hover,
.page-about .about-index__list a:focus-visible {
  color: var(--orange);
  border-left-color: var(--orange);
  background: var(--ink-800);
  outline: none;
}

@media (min-width: 1024px) {
  .page-about .about-index {
    position: sticky;
    top: calc(var(--top-h) + 20px);
    align-self: start;
    padding-top: 6px;
  }

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

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding-bottom: clamp(28px, 4vw, 48px);
  border-bottom: 1px solid var(--line);
}

.page-about .about-hero h1 {
  margin: 14px 0 0;
  max-width: 18ch;
  font-family: var(--font-display);
  font-weight: 300;
  font-size: clamp(34px, 6vw, 76px);
  line-height: 1.03;
  letter-spacing: -0.02em;
}

.page-about .about-hero__lead {
  margin: clamp(18px, 2.6vw, 26px) 0 0;
  max-width: 60ch;
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.8;
  color: var(--text-dim);
}

.page-about .about-facts {
  list-style: none;
  margin: clamp(24px, 3.5vw, 40px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

@media (min-width: 768px) {
  .page-about .about-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

.page-about .about-facts li {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: clamp(12px, 2vw, 18px) 14px;
  background: var(--ink-900);
}

.page-about .about-facts .num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(22px, 2.8vw, 32px);
  letter-spacing: -0.01em;
  color: var(--cyan);
}

.page-about .about-facts__label {
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--stone);
}

/* ---------- 章节骨架 ---------- */
.page-about .about-chapter {
  padding-top: clamp(36px, 5vw, 64px);
  margin-top: clamp(36px, 5vw, 64px);
  border-top: 1px solid var(--line);
}

.page-about .about-chapter:first-of-type {
  border-top: 0;
  margin-top: 0;
  padding-top: clamp(28px, 4vw, 44px);
}

.page-about .chapter-no {
  display: block;
  font-family: var(--font-display);
  font-weight: 300;
  font-size: clamp(52px, 9vw, 96px);
  line-height: 0.82;
  letter-spacing: -0.03em;
  color: var(--ink-700);
}

.page-about .about-chapter h2 {
  margin: 10px 0 0;
  max-width: 24ch;
  font-family: var(--font-display);
  font-weight: 300;
  font-size: clamp(24px, 3.2vw, 40px);
  line-height: 1.18;
  letter-spacing: -0.01em;
}

.page-about .about-chapter p {
  margin: 16px 0 0;
  max-width: 62ch;
  font-size: 16px;
  line-height: 1.78;
  color: var(--text-dim);
}

.page-about .about-chapter a:not(.btn) {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(79, 227, 193, 0.35);
}

.page-about .about-chapter a:not(.btn):hover,
.page-about .about-chapter a:not(.btn):focus-visible {
  border-bottom-color: var(--cyan);
  outline: none;
}

.page-about .pull {
  margin: clamp(22px, 3vw, 32px) 0;
  max-width: 48ch;
  padding: 2px 0 2px 20px;
  border-left: 3px solid var(--terra);
  font-size: clamp(17px, 1.8vw, 20px);
  line-height: 1.7;
  color: var(--paper);
}

/* ---------- 四道工序 ---------- */
.page-about .split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(20px, 3vw, 36px);
  margin-top: clamp(20px, 3vw, 28px);
}

@media (min-width: 960px) {
  .page-about .split {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
    align-items: start;
  }
}

.page-about .flow {
  display: block;
  width: 100%;
  height: auto;
  margin: 4px 0 0;
}

.page-about .flow path {
  fill: none;
  stroke: var(--ink-700);
  stroke-width: 1.5;
  stroke-linejoin: round;
}

.page-about .flow rect {
  fill: var(--ink-700);
}

.page-about .flow-notes {
  list-style: none;
  margin: clamp(18px, 2.5vw, 24px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 18px;
}

@media (min-width: 640px) {
  .page-about .flow-notes {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 1280px) {
  .page-about .flow-notes {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

.page-about .flow-notes li {
  padding-top: 12px;
  border-top: 1px solid var(--line-strong);
}

.page-about .flow-notes .num {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.14em;
  color: var(--orange);
}

.page-about .flow-notes h3 {
  margin: 8px 0 0;
  font-size: 17px;
  font-weight: 500;
  color: var(--paper);
}

.page-about .about-chapter .flow-notes p {
  margin: 8px 0 0;
  max-width: none;
  font-size: 14px;
  line-height: 1.72;
}

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

.page-about .split__media img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--line);
  filter: saturate(0.75) contrast(1.02);
}

.page-about .split__media figcaption {
  margin-top: 10px;
  font-size: 12px;
  line-height: 1.6;
  letter-spacing: 0.02em;
  color: var(--stone);
}

/* ---------- 时间线 ---------- */
.page-about .about-texture {
  margin: 0 0 clamp(20px, 3vw, 32px);
}

.page-about .about-texture img {
  display: block;
  width: 100%;
  height: clamp(110px, 16vw, 190px);
  object-fit: cover;
  object-position: 50% 45%;
  border: 1px solid var(--line);
  filter: saturate(0.65);
  opacity: 0.82;
}

.page-about .timeline {
  list-style: none;
  margin: clamp(16px, 2.5vw, 26px) 0 0;
  padding: 0;
}

.page-about .tl-item {
  display: grid;
  grid-template-columns: 76px minmax(0, 1fr);
  align-items: start;
  gap: 8px 16px;
  padding: clamp(14px, 2vw, 20px) 0;
  border-bottom: 1px solid var(--line);
  scroll-margin-top: calc(var(--top-h) + 24px);
  transition: background 0.2s var(--ease);
}

.page-about .tl-item:hover {
  background: rgba(22, 48, 42, 0.55);
}

@media (min-width: 900px) {
  .page-about .tl-item {
    grid-template-columns: 128px 44px minmax(0, 1fr);
    align-items: center;
    column-gap: clamp(14px, 2vw, 28px);
  }

  .page-about .tl-item:nth-child(odd) {
    padding-left: clamp(0px, 3vw, 54px);
  }
}

.page-about .tl-year {
  display: inline-block;
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(20px, 2.4vw, 30px);
  letter-spacing: 0.01em;
  color: var(--stone);
  transform-origin: left center;
  transition: color 0.25s var(--ease), transform 0.25s var(--ease);
}

.page-about .tl-item:hover .tl-year,
.page-about .tl-item:focus-within .tl-year {
  color: var(--orange);
  transform: scale(1.08);
}

.page-about .tl-rule {
  display: none;
}

@media (min-width: 900px) {
  .page-about .tl-rule {
    display: block;
    height: 1px;
    background: var(--line-strong);
    transition: background 0.25s var(--ease);
  }

  .page-about .tl-item:hover .tl-rule {
    background: var(--orange);
  }
}

.page-about .tl-body h3 {
  margin: 0;
  font-size: 17px;
  font-weight: 500;
  color: var(--paper);
}

.page-about .about-chapter .tl-body p {
  margin: 8px 0 0;
  max-width: 52ch;
  font-size: 14px;
  line-height: 1.72;
}

/* ---------- 团队分工 ---------- */
.page-about .crew-bar {
  display: flex;
  gap: 3px;
  height: 12px;
  margin: clamp(22px, 3vw, 30px) 0 0;
}

.page-about .crew-bar__seg {
  height: 100%;
}

.page-about .crew-bar__seg--eng { flex: 15 1 0; background: var(--ink-700); }
.page-about .crew-bar__seg--edit { flex: 18 1 0; background: var(--cyan); }
.page-about .crew-bar__seg--prod { flex: 9 1 0; background: var(--orange); }
.page-about .crew-bar__seg--ops { flex: 4 1 0; background: var(--terra); }

.page-about .crew {
  list-style: none;
  margin: clamp(14px, 2vw, 20px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
}

@media (min-width: 820px) {
  .page-about .crew {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    column-gap: clamp(24px, 3vw, 48px);
  }
}

.page-about .crew li {
  display: grid;
  grid-template-columns: 10px minmax(0, 1fr) auto;
  column-gap: 12px;
  row-gap: 6px;
  align-items: baseline;
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .crew__swatch {
  display: block;
  width: 10px;
  height: 10px;
  align-self: center;
}

.page-about .crew__swatch--eng { background: var(--ink-700); }
.page-about .crew__swatch--edit { background: var(--cyan); }
.page-about .crew__swatch--prod { background: var(--orange); }
.page-about .crew__swatch--ops { background: var(--terra); }

.page-about .crew__name {
  font-size: 16px;
  color: var(--paper);
}

.page-about .crew__num {
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 700;
  color: var(--cyan);
}

.page-about .about-chapter .crew li p {
  grid-column: 2 / -1;
  margin: 0;
  max-width: none;
  font-size: 14px;
  line-height: 1.7;
}

.page-about .about-chapter .crew-note {
  margin-top: clamp(18px, 2.5vw, 24px);
  padding-left: 14px;
  max-width: 58ch;
  border-left: 2px solid var(--ink-700);
  font-size: 14px;
  line-height: 1.7;
  color: var(--stone);
}

.page-about .about-photo {
  margin: clamp(24px, 3.5vw, 40px) 0 0;
}

.page-about .about-photo img {
  display: block;
  width: 100%;
  height: auto;
  border: 1px solid var(--line);
  filter: saturate(0.75);
}

/* ---------- 合作生态 ---------- */
.page-about .partner-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin-top: clamp(22px, 3vw, 32px);
  background: var(--line);
  border-block: 1px solid var(--line);
}

@media (min-width: 760px) {
  .page-about .partner-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

.page-about .partner {
  padding: clamp(18px, 2.6vw, 26px);
  background: var(--ink-800);
}

.page-about .partner .num {
  font-family: var(--font-mono);
  font-weight: 700;
  font-size: clamp(30px, 4vw, 44px);
  line-height: 1;
  color: var(--yellow);
}

.page-about .partner h3 {
  margin: 12px 0 0;
  font-size: 17px;
  font-weight: 500;
  color: var(--paper);
}

.page-about .about-chapter .partner p {
  margin: 10px 0 0;
  max-width: 34ch;
  font-size: 14px;
  line-height: 1.72;
}

.page-about .about-chapter > .btn {
  margin-top: clamp(22px, 3vw, 32px);
}

/* ---------- 联系 ---------- */
.page-about .contact-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(18px, 3vw, 28px);
  margin-top: clamp(22px, 3vw, 32px);
}

@media (min-width: 760px) {
  .page-about .contact-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

.page-about .contact-grid__item {
  padding-top: 14px;
  border-top: 1px solid var(--line-strong);
}

.page-about .about-chapter .contact-grid__value {
  margin: 10px 0 0;
  max-width: none;
  font-family: var(--font-mono);
  font-size: clamp(14px, 1.5vw, 16px);
  line-height: 1.6;
  color: var(--paper);
  overflow-wrap: anywhere;
}

.page-about .about-chapter .contact-grid__note {
  margin: 8px 0 0;
  max-width: none;
  font-size: 13px;
  color: var(--stone);
}

.page-about .about-contact .btn {
  margin-top: clamp(24px, 3.5vw, 36px);
}

/* ---------- 降低动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .tl-year,
  .page-about .tl-rule,
  .page-about .tl-item,
  .page-about .about-index__list a {
    transition: none;
  }

  .page-about .tl-item:hover .tl-year,
  .page-about .tl-item:focus-within .tl-year {
    transform: none;
  }
}