.page-about {
  --about-rail-w: 168px;
  --about-dark-line: rgba(247, 243, 236, .16);
}

.page-about .crumbs {
  padding: 20px 0 8px;
}

.page-about .crumbs ol {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  list-style: none;
  margin: 0;
  padding: 0;
  font-size: 13px;
  color: var(--warm);
}

.page-about .crumbs li + li::before {
  content: "/";
  margin-right: 8px;
  color: var(--line);
}

.page-about .crumbs a {
  color: var(--warm);
  text-decoration: none;
}

.page-about .crumbs a:hover {
  color: var(--coral-press);
}

/* 首屏 */

.page-about .about-hero {
  padding-top: 14px;
}

.page-about .about-hero__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 30px;
}

.page-about .about-hero__title {
  font-size: clamp(34px, 7vw, 58px);
  line-height: 1.1;
  letter-spacing: .01em;
  color: var(--ink);
  margin: 14px 0 20px;
}

.page-about .about-hero__lede {
  max-width: 46ch;
  color: var(--ink);
}

.page-about .about-hero__sig {
  margin: 22px 0 0;
  padding-left: 14px;
  border-left: 2px solid var(--coral);
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--warm);
}

.page-about .about-hero__aside {
  position: relative;
  background-color: var(--ink);
  background-image:
    linear-gradient(rgba(247, 243, 236, .07) 1px, transparent 1px),
    linear-gradient(90deg, rgba(247, 243, 236, .07) 1px, transparent 1px);
  background-size: 32px 32px;
  color: var(--paper);
  padding: 30px 46px 24px 22px;
}

.page-about .about-hero__flag {
  position: absolute;
  top: 14px;
  right: 10px;
  writing-mode: vertical-rl;
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--amber);
}

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

.page-about .about-hero__data .data-list__row {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  gap: 6px 16px;
  padding: 11px 0;
  border-bottom: 1px solid var(--about-dark-line);
}

.page-about .about-hero__data .data-list__row:last-child {
  border-bottom: 0;
}

.page-about .about-hero__data .data-list__key {
  font-size: 13px;
  letter-spacing: .06em;
  color: rgba(247, 243, 236, .58);
}

.page-about .about-hero__data .data-list__val {
  margin: 0;
  font-size: 15px;
  font-weight: 700;
  color: var(--paper);
}

/* 时间线 */

.page-about .about-line__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 20px;
}

.page-about .about-line__rail {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding-bottom: 6px;
  scrollbar-width: none;
}

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

.page-about .about-line__tick {
  display: inline-flex;
  align-items: center;
  gap: 9px;
  flex: 0 0 auto;
  padding: 10px 13px;
  border: 1px solid var(--line);
  background: var(--card);
  color: var(--ink);
  text-decoration: none;
  white-space: nowrap;
  transition: border-color var(--t-fast) var(--ease), background var(--t-fast) var(--ease);
}

.page-about .about-line__tick-n {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: .14em;
  color: var(--coral);
}

.page-about .about-line__tick-t {
  font-size: 14px;
}

.page-about .about-line__tick:hover {
  border-color: var(--coral);
}

.page-about .about-line__tick:hover .about-line__tick-t {
  color: var(--coral-press);
}

.page-about .about-line__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 34px;
}

.page-about .about-line__item {
  scroll-margin-top: 120px;
  min-width: 0;
}

.page-about .about-line__card {
  position: relative;
  background: var(--card);
  border: 1px solid var(--line);
  padding: 24px 20px 20px;
}

.page-about .about-line__card--key {
  border-color: rgba(255, 90, 54, .5);
}

.page-about .about-line__card--key::before {
  content: "";
  position: absolute;
  top: -1px;
  right: -1px;
  width: 0;
  height: 0;
  border-style: solid;
  border-width: 0 26px 26px 0;
  border-color: transparent var(--coral) transparent transparent;
}

.page-about .about-line__card-head {
  display: grid;
  gap: 6px;
  margin-bottom: 14px;
}

.page-about .about-line__no {
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .22em;
  color: var(--coral);
}

.page-about .about-line__title {
  margin: 0;
  font-size: clamp(20px, 3.2vw, 26px);
  line-height: 1.35;
  color: var(--deep);
  letter-spacing: .01em;
}

.page-about .about-line__when {
  margin: 0;
  font-size: 13px;
  color: var(--warm);
  letter-spacing: .04em;
}

.page-about .about-line__text {
  margin: 0 0 16px;
  font-size: 16.5px;
  line-height: 1.85;
  color: var(--ink);
}

.page-about .about-line__media {
  margin: 0 0 16px;
}

.page-about .about-line__more {
  border-top: 1px solid var(--line);
  padding-top: 10px;
}

.page-about .about-line__more .expand__head {
  font-size: 14px;
  color: var(--deep);
  cursor: pointer;
}

.page-about .about-line__more .expand__body p {
  margin: 10px 0 2px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--warm);
}

/* 团队 */

.page-about .about-crew__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 28px;
}

.page-about .about-crew__bands {
  display: flex;
  flex-direction: column;
  border: 1px solid var(--line);
  background: var(--card);
}

.page-about .about-crew__band {
  padding: 20px 18px;
  display: flex;
  flex-direction: column;
  gap: 5px;
  min-width: 0;
  outline-offset: -3px;
  transition: flex-grow var(--t-mid) var(--ease);
}

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

.page-about .about-crew__band--edit {
  background: var(--amber);
  color: var(--ink);
}

.page-about .about-crew__band--tech {
  background: var(--deep);
  color: var(--paper);
}

.page-about .about-crew__band--ux {
  background: var(--mint);
  color: var(--ink);
}

.page-about .about-crew__name {
  font-size: 18px;
  font-weight: 700;
  letter-spacing: .02em;
}

.page-about .about-crew__hint {
  font-size: 13px;
  opacity: .8;
}

.page-about .about-crew__tasks {
  list-style: none;
  margin: 10px 0 0;
  padding: 0;
  font-size: 13.5px;
  line-height: 1.75;
}

.page-about .about-crew__tasks li {
  position: relative;
  padding-left: 14px;
  margin-bottom: 4px;
}

.page-about .about-crew__tasks li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .78em;
  width: 7px;
  height: 1px;
  background: currentColor;
  opacity: .65;
}

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

/* 本地选题 */

.page-about .about-local__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 28px;
  align-items: center;
}

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

.page-about .about-local__lede {
  margin: 0 0 6px;
  font-size: 17px;
  line-height: 1.85;
  color: var(--ink);
}

.page-about .about-local__points {
  list-style: none;
  margin: 22px 0 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .about-local__points li {
  display: grid;
  grid-template-columns: 30px minmax(0, 1fr);
  gap: 12px;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--ink);
}

.page-about .about-local__idx {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 30px;
  height: 22px;
  background: var(--soft);
  color: var(--deep);
  font-size: 11px;
  font-weight: 700;
  letter-spacing: .08em;
}

/* 渠道 */

.page-about .about-reach__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-reach__channel {
  background: var(--card);
  padding: 24px 20px;
  display: flex;
  flex-direction: column;
  gap: 10px;
  min-width: 0;
}

.page-about .about-reach__channel h3 {
  margin: 0;
  font-size: 17px;
  color: var(--deep);
  letter-spacing: .02em;
}

.page-about .about-reach__value {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.6;
  color: var(--ink);
  word-break: break-all;
}

.page-about .about-reach__copy {
  align-self: flex-start;
  border: 1px solid var(--line);
  background: var(--paper);
  color: var(--deep);
  font-size: 13px;
  padding: 7px 12px;
  cursor: pointer;
  transition: border-color var(--t-fast) var(--ease), color var(--t-fast) var(--ease), background var(--t-fast) var(--ease);
}

.page-about .about-reach__copy:hover {
  border-color: var(--coral);
  color: var(--coral-press);
}

.page-about .about-reach__legal {
  margin: 18px 0 0;
  font-size: 13.5px;
  color: var(--warm);
  letter-spacing: .03em;
}

/* 前后对照 */

.page-about .about-shift__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  border: 1px solid var(--line);
}

.page-about .about-shift__col {
  padding: 26px 22px;
}

.page-about .about-shift__col--old {
  background: var(--ink);
  color: var(--paper);
}

.page-about .about-shift__col--now {
  background: var(--soft);
  color: var(--ink);
}

.page-about .about-shift__col h3 {
  margin: 0 0 16px;
  font-size: 20px;
  letter-spacing: .04em;
}

.page-about .about-shift__col ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 13px;
  font-size: 15.5px;
  line-height: 1.8;
}

.page-about .about-shift__col li {
  position: relative;
  padding-left: 17px;
}

.page-about .about-shift__col li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .82em;
  width: 9px;
  height: 1px;
  background: var(--coral);
}

/* 结尾 */

.page-about .about-next {
  background: var(--ink);
  color: var(--paper);
  padding-bottom: 60px;
}

.page-about .about-next__title {
  margin: 0 0 14px;
  color: var(--paper);
}

.page-about .about-next__lede {
  max-width: 60ch;
  color: rgba(247, 243, 236, .78);
}

.page-about .about-next__links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin: 26px 0 0;
}

.page-about .about-next__links .btn--ghost {
  background: transparent;
  color: var(--paper);
  border-color: rgba(247, 243, 236, .45);
}

.page-about .about-next__links .btn--ghost:hover {
  color: var(--amber);
  border-color: var(--amber);
}

.page-about .about-next__note {
  margin: 22px 0 0;
  max-width: 62ch;
  color: rgba(247, 243, 236, .7);
}

.page-about .about-next__note .text-link {
  color: var(--amber);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* 中屏与桌面 */

@media (min-width: 720px) {
  .page-about .about-crew__bands {
    flex-direction: row;
    align-items: stretch;
  }

  .page-about .about-crew__band + .about-crew__band {
    border-top: 0;
    border-left: 1px solid var(--line);
  }

  .page-about .about-crew__band--edit {
    flex: 40 1 0;
  }

  .page-about .about-crew__band--tech {
    flex: 33 1 0;
  }

  .page-about .about-crew__band--ux {
    flex: 27 1 0;
  }

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

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

  .page-about .about-shift__col--old {
    border-right: 1px solid var(--line);
  }
}

@media (hover: hover) and (min-width: 720px) {
  .page-about .about-crew__tasks {
    max-height: 0;
    opacity: 0;
    overflow: hidden;
    transition: max-height var(--t-mid) var(--ease), opacity var(--t-mid) var(--ease);
  }

  .page-about .about-crew__band:hover .about-crew__tasks,
  .page-about .about-crew__band:focus-within .about-crew__tasks {
    max-height: 180px;
    opacity: 1;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, .85fr);
    gap: 56px;
    align-items: start;
  }

  .page-about .about-line__grid {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: 48px;
  }

  .page-about .about-line__rail {
    position: sticky;
    top: 108px;
    align-self: start;
    flex-direction: column;
    gap: 0;
    overflow: visible;
    padding-bottom: 0;
  }

  .page-about .about-line__tick {
    position: relative;
  }

  .page-about .about-line__tick + .about-line__tick {
    margin-top: 10px;
  }

  .page-about .about-line__tick::before {
    content: "";
    position: absolute;
    left: 20px;
    top: -11px;
    width: 1px;
    height: 10px;
    background: var(--line);
  }

  .page-about .about-line__tick:first-child::before {
    display: none;
  }

  .page-about .about-line__list {
    gap: 56px;
  }

  .page-about .about-line__card {
    padding: 30px 28px 26px;
  }

  .page-about .about-crew__grid {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, .92fr);
    gap: 44px;
    align-items: start;
  }

  .page-about .about-local__grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: 52px;
  }
}

@media (min-width: 1080px) {
  .page-about .about-reach__grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}
</PAGE_CSS>>>

等等，最后那个 `/PAGE_CSS` 写错了，我已经在标记里用 `` 结束了。上面输出已经完成，不需要再补。