.page-about {
  display: block;
  background: var(--xm-tile);
}

/* ============ 首屏 ============ */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: 32px 0 52px;
  background: var(--xm-tile);
}

.page-about .about-hero__bg {
  position: absolute;
  top: -24%;
  right: -34%;
  width: 96%;
  height: 138%;
  background: var(--xm-bamboo-900);
  clip-path: polygon(42% 0, 100% 0, 100% 100%, 0 62%);
  opacity: .07;
  pointer-events: none;
}

.page-about .about-hero__bg::after {
  content: "";
  position: absolute;
  inset: 0;
  background: repeating-linear-gradient(118deg, rgba(255, 255, 255, .07) 0 2px, transparent 2px 16px);
}

.page-about .about-hero__inner {
  position: relative;
  z-index: 1;
}

.page-about .about-hero__copy {
  max-width: var(--xm-textw);
}

.page-about .about-hero__title {
  margin: 14px 0 0;
  color: var(--xm-ink);
}

.page-about .about-hero__lede {
  margin: 18px 0 0;
  max-width: 50ch;
  color: var(--xm-grey);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

.page-about .about-hero__facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 34px 0 0;
  padding: 1px;
  max-width: 560px;
  background: var(--xm-line);
}

.page-about .about-fact {
  padding: 14px 16px;
  background: var(--xm-paper);
}

.page-about .about-fact__label {
  margin: 0;
  font-size: .72rem;
  font-weight: 600;
  letter-spacing: .14em;
  color: var(--xm-grey);
}

.page-about .about-fact__value {
  margin: 6px 0 0;
  font-family: var(--xm-font-num);
  font-weight: 600;
  font-size: 1.3rem;
  line-height: 1.2;
  color: var(--xm-bamboo-900);
}

/* ============ 品牌起点 ============ */
.page-about .about-origin {
  padding: 60px 0;
  background: var(--xm-paper);
}

.page-about .about-origin__head {
  margin-bottom: 28px;
}

.page-about .about-origin__grid {
  display: grid;
  gap: 28px;
}

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

.page-about .about-origin__media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  border: 1px solid var(--xm-bamboo-700);
  clip-path: polygon(0 0, calc(100% - var(--xm-cut)) 0, 100% var(--xm-cut), 100% 100%, var(--xm-cut) 100%, 0 calc(100% - var(--xm-cut)));
}

.page-about .about-origin__body p {
  margin: 0 0 16px;
  color: var(--xm-ink);
}

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

.page-about .about-steps {
  list-style: none;
  margin: 20px 0 20px;
  padding: 0;
  display: grid;
  gap: 6px;
  counter-reset: none;
}

.page-about .about-steps__item {
  display: flex;
  align-items: baseline;
  gap: 10px;
  padding: 10px 14px;
  background: var(--xm-tile);
  border-left: 3px solid var(--xm-bamboo-700);
  font-size: .93rem;
  color: var(--xm-ink);
  transition: border-color .2s ease, transform .2s ease;
}

.page-about .about-steps__item:hover {
  border-left-color: var(--xm-red);
  transform: translateX(2px);
}

.page-about .about-steps__no {
  flex: none;
  font-family: var(--xm-font-num);
  font-weight: 600;
  font-size: .8rem;
  color: var(--xm-red);
  letter-spacing: .04em;
}

/* ============ 团队分工 ============ */
.page-about .about-team {
  padding: 60px 0;
  background: var(--xm-bamboo-900);
  color: var(--xm-tile);
}

.page-about .about-team .xm-eyebrow {
  color: var(--xm-gold);
}

.page-about .about-team .xm-h2 {
  color: var(--xm-tile);
}

.page-about .about-team__lede {
  margin: 14px 0 0;
  max-width: 52ch;
  color: rgba(245, 242, 233, .72);
}

.page-about .about-team__bars {
  list-style: none;
  margin: 32px 0 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .about-team__bar {
  padding: 18px 18px 20px;
  background: rgba(245, 242, 233, .05);
  border: 1px solid var(--xm-hair);
  border-left: 4px solid var(--xm-teal);
  transition: background-color .22s ease, border-left-color .22s ease;
  outline-offset: 3px;
}

.page-about .about-team__bar--rules {
  border-left-color: var(--xm-teal);
}

.page-about .about-team__bar--tech {
  border-left-color: var(--xm-gold);
}

.page-about .about-team__bar--ops {
  border-left-color: var(--xm-red);
}

.page-about .about-team__bar:hover,
.page-about .about-team__bar:focus-visible {
  background: rgba(245, 242, 233, .1);
}

.page-about .about-team__bar:focus-visible {
  outline: 2px solid var(--xm-teal);
}

.page-about .about-team__meta {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 12px;
}

.page-about .about-team__name {
  font-weight: 700;
  font-size: 1.06rem;
  color: var(--xm-tile);
}

.page-about .about-team__count {
  font-family: var(--xm-font-num);
  font-weight: 600;
  font-size: 1.12rem;
  color: var(--xm-gold);
  white-space: nowrap;
}

.page-about .about-team__track {
  position: relative;
  height: 7px;
  margin: 12px 0;
  background: rgba(207, 216, 210, .16);
  overflow: hidden;
}

.page-about .about-team__fill {
  display: block;
  height: 100%;
}

.page-about .about-team__bar--rules .about-team__fill {
  width: 34.6%;
  background: var(--xm-teal);
}

.page-about .about-team__bar--tech .about-team__fill {
  width: 42.3%;
  background: var(--xm-gold);
}

.page-about .about-team__bar--ops .about-team__fill {
  width: 23.1%;
  background: var(--xm-red);
}

.page-about .about-team__desc {
  margin: 0;
  font-size: .92rem;
  line-height: 1.72;
  color: rgba(245, 242, 233, .74);
}

/* ============ 版本演进 ============ */
.page-about .about-road {
  padding: 60px 0;
  background: var(--xm-tile);
}

.page-about .about-road__head {
  margin-bottom: 30px;
}

.page-about .about-road__lede {
  margin: 14px 0 0;
  max-width: 54ch;
  color: var(--xm-grey);
}

.page-about .about-tl {
  list-style: none;
  margin: 0;
  padding: 0 0 0 24px;
  position: relative;
}

.page-about .about-tl::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: linear-gradient(180deg, var(--xm-bamboo-700), var(--xm-line));
}

.page-about .about-tl__item {
  position: relative;
  display: grid;
  gap: 8px;
  padding-bottom: 18px;
}

.page-about .about-tl__marker {
  display: flex;
  align-items: center;
  gap: 10px;
}

.page-about .about-tl__dot {
  position: absolute;
  left: -24px;
  top: 7px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--xm-gold);
  border: 2px solid var(--xm-tile);
  box-sizing: content-box;
}

.page-about .about-tl__item--now .about-tl__dot {
  background: var(--xm-red);
  box-shadow: 0 0 0 4px rgba(196, 61, 46, .18);
}

.page-about .about-tl__year {
  font-family: var(--xm-font-num);
  font-weight: 600;
  font-size: 1.02rem;
  letter-spacing: .04em;
  color: var(--xm-bamboo-700);
}

.page-about .about-tl__item--now .about-tl__year {
  color: var(--xm-red);
}

.page-about .about-tl__panel {
  background: var(--xm-paper);
  border: 1px solid var(--xm-line);
  clip-path: polygon(0 0, calc(100% - var(--xm-cut)) 0, 100% var(--xm-cut), 100% 100%, var(--xm-cut) 100%, 0 calc(100% - var(--xm-cut)));
  transition: border-color .22s ease;
}

.page-about .about-tl__panel:hover {
  border-color: var(--xm-red);
}

.page-about .about-tl__summary {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px;
  padding: 14px 18px;
  cursor: pointer;
  list-style: none;
  outline-offset: -2px;
}

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

.page-about .about-tl__summary::after {
  content: "＋";
  margin-left: auto;
  font-family: var(--xm-font-num);
  font-size: .95rem;
  color: var(--xm-bamboo-700);
}

.page-about .about-tl__panel[open] .about-tl__summary::after {
  content: "－";
  color: var(--xm-red);
}

.page-about .about-tl__title {
  font-weight: 700;
  font-size: 1rem;
  color: var(--xm-ink);
}

.page-about .about-tl__text {
  margin: 0;
  padding: 0 18px 18px;
  font-size: .93rem;
  line-height: 1.75;
  color: var(--xm-grey);
}

.page-about .about-tl__text a {
  color: var(--xm-red);
  font-weight: 600;
  text-decoration: underline;
  text-underline-offset: 3px;
}

.page-about .about-road__media {
  margin: 32px 0 0;
}

.page-about .about-road__media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 2 / 1;
  object-fit: cover;
  border: 1px solid var(--xm-line);
}

/* ============ 服务范围 ============ */
.page-about .about-region {
  padding: 60px 0;
  background: var(--xm-paper);
}

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

.page-about .about-region__body p {
  margin: 16px 0 0;
  color: var(--xm-ink);
}

.page-about .about-region__dots {
  list-style: none;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 8px;
  margin: 24px 0 0;
  padding: 0;
}

.page-about .about-region__dot {
  position: relative;
  display: block;
  padding: 9px 10px 9px 24px;
  font-size: .85rem;
  color: var(--xm-ink);
  background: var(--xm-tile);
  border: 1px solid var(--xm-line);
  transition: border-color .2s ease, background-color .2s ease, color .2s ease;
}

.page-about .about-region__dot::before {
  content: "";
  position: absolute;
  left: 9px;
  top: 50%;
  width: 7px;
  height: 7px;
  border-radius: 50%;
  transform: translateY(-50%);
  background: var(--xm-gold);
  box-shadow: 0 0 0 3px rgba(201, 162, 39, .16);
  transition: background-color .2s ease, box-shadow .2s ease;
}

.page-about .about-region__dot:hover,
.page-about .about-region__dot:focus-visible {
  border-color: var(--xm-red);
  background: var(--xm-paper);
  color: var(--xm-red);
  outline: none;
}

.page-about .about-region__dot:hover::before,
.page-about .about-region__dot:focus-visible::before {
  background: var(--xm-red);
  box-shadow: 0 0 0 4px rgba(196, 61, 46, .18);
}

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

.page-about .about-region__media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  border: 1px solid var(--xm-bamboo-700);
  clip-path: polygon(0 0, calc(100% - var(--xm-cut)) 0, 100% var(--xm-cut), 100% 100%, var(--xm-cut) 100%, 0 calc(100% - var(--xm-cut)));
}

/* ============ 长期坚持 ============ */
.page-about .about-principles {
  padding: 60px 0;
  background: var(--xm-felt);
  color: var(--xm-tile);
}

.page-about .about-principles .xm-eyebrow {
  color: var(--xm-gold);
}

.page-about .about-principles .xm-h2 {
  color: var(--xm-tile);
}

.page-about .about-principles__grid {
  display: grid;
  gap: 14px;
  margin-top: 30px;
}

.page-about .about-principle {
  padding: 20px 18px 22px;
  background: rgba(245, 242, 233, .05);
  border-top: 2px solid var(--xm-gold);
  transition: background-color .22s ease, border-top-color .22s ease;
}

.page-about .about-principle:hover {
  background: rgba(245, 242, 233, .1);
  border-top-color: var(--xm-red);
}

.page-about .about-principle__no {
  margin: 0;
  font-family: var(--xm-font-num);
  font-weight: 600;
  font-size: .78rem;
  letter-spacing: .12em;
  color: var(--xm-gold);
}

.page-about .about-principle__title {
  margin: 10px 0 8px;
  font-size: 1.04rem;
  font-weight: 700;
  color: var(--xm-tile);
}

.page-about .about-principle__text {
  margin: 0;
  font-size: .9rem;
  line-height: 1.72;
  color: rgba(245, 242, 233, .72);
}

/* ============ 关联入口 ============ */
.page-about .about-next {
  padding: 54px 0 68px;
  background: var(--xm-tile);
}

.page-about .about-next__list {
  list-style: none;
  margin: 26px 0 0;
  padding: 1px;
  display: grid;
  gap: 1px;
  background: var(--xm-line);
}

.page-about .about-next__link {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 18px 20px;
  background: var(--xm-paper);
  color: var(--xm-ink);
  text-decoration: none;
  transition: background-color .22s ease, color .22s ease;
}

.page-about .about-next__link:hover,
.page-about .about-next__link:focus-visible {
  background: var(--xm-bamboo-900);
  color: var(--xm-tile);
  outline: none;
}

.page-about .about-next__label {
  font-weight: 700;
  font-size: 1.04rem;
}

.page-about .about-next__hint {
  font-size: .86rem;
  line-height: 1.6;
  color: var(--xm-grey);
  transition: color .22s ease;
}

.page-about .about-next__link:hover .about-next__hint,
.page-about .about-next__link:focus-visible .about-next__hint {
  color: var(--xm-teal);
}

/* ============ 小屏以上的微调 ============ */
@media (min-width: 560px) {
  .page-about .about-region__dots {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

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

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

  .page-about .about-hero__facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    max-width: 680px;
  }
}

/* ============ 桌面布局 ============ */
@media (min-width: 900px) {
  .page-about .about-hero {
    padding: 56px 0 92px;
  }

  .page-about .about-hero__bg {
    top: 0;
    right: 0;
    width: 42%;
    height: 100%;
    opacity: 1;
    clip-path: polygon(20% 0, 100% 0, 100% 100%, 0 100%);
  }

  .page-about .about-hero__copy {
    max-width: 48ch;
  }

  .page-about .about-origin,
  .page-about .about-team,
  .page-about .about-road,
  .page-about .about-region,
  .page-about .about-principles {
    padding: 84px 0;
  }

  .page-about .about-next {
    padding: 72px 0 92px;
  }

  .page-about .about-origin__grid {
    grid-template-columns: 5fr 7fr;
    gap: 44px;
    align-items: start;
  }

  .page-about .about-origin__media {
    margin-top: 8px;
  }

  .page-about .about-team__bars {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
  }

  .page-about .about-region__grid {
    grid-template-columns: 6fr 5fr;
    gap: 48px;
    align-items: center;
  }

  .page-about .about-region__dots {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  /* 纵向时间线转成左侧年份索引 + 右侧堆叠面板 */
  .page-about .about-tl {
    padding-left: 0;
  }

  .page-about .about-tl::before {
    left: 145px;
    top: 10px;
    bottom: 10px;
  }

  .page-about .about-tl__item {
    grid-template-columns: 128px minmax(0, 1fr);
    gap: 44px;
    align-items: start;
    padding-bottom: 6px;
  }

  .page-about .about-tl__marker {
    justify-content: flex-end;
    padding-top: 8px;
  }

  .page-about .about-tl__dot {
    left: 139px;
    top: 15px;
  }

  .page-about .about-tl__panel {
    position: relative;
    margin-bottom: 14px;
  }

  .page-about .about-tl__item:nth-child(even) .about-tl__panel {
    margin-left: 34px;
    margin-top: -5px;
  }

  .page-about .about-road__media {
    margin-top: 44px;
  }
}

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

  .page-about .about-next__list {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-team__bar,
  .page-about .about-steps__item,
  .page-about .about-tl__panel,
  .page-about .about-principle,
  .page-about .about-next__link,
  .page-about .about-region__dot {
    transition: none;
  }

  .page-about .about-steps__item:hover {
    transform: none;
  }
}
<<<END>>>