.page-about {
  --about-axis: rgba(127, 227, 232, .2);
  --about-card: rgba(11, 35, 56, .62);
  display: block;
}

.page-about .crumbs {
  margin: clamp(16px, 3vw, 26px) 0 0;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding-top: clamp(18px, 3vw, 34px);
  padding-bottom: clamp(24px, 4vw, 46px);
}

.page-about .about-hero__inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(18px, 3vw, 34px);
  align-items: stretch;
}

.page-about .about-hero__frame {
  position: relative;
  border: 1px solid var(--about-axis);
  padding: clamp(24px, 4vw, 52px) clamp(20px, 3.4vw, 46px);
  background:
    linear-gradient(158deg, rgba(18, 58, 87, .62), rgba(6, 24, 38, .12) 68%),
    var(--deep);
}

.page-about .about-hero__frame::before {
  content: "";
  position: absolute;
  left: -1px;
  top: -1px;
  width: 54px;
  height: 54px;
  border-top: 2px solid var(--signal);
  border-left: 2px solid var(--signal);
  opacity: .85;
  pointer-events: none;
}

.page-about .about-hero__frame::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  top: 12px;
  height: 8px;
  background-image: repeating-linear-gradient(90deg, rgba(127, 227, 232, .45) 0 1px, transparent 1px 16px);
  opacity: .55;
  pointer-events: none;
}

.page-about .about-hero__coord {
  margin: 0 0 clamp(14px, 2vw, 22px);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--signal);
  text-transform: uppercase;
}

.page-about .about-hero__title {
  margin: 0 0 clamp(16px, 2.4vw, 26px);
  font-size: var(--fs-1);
  font-weight: 900;
  line-height: 1.02;
  letter-spacing: -.02em;
  color: var(--text);
}

.page-about .about-hero__lead {
  margin: 0;
  max-width: 46ch;
  font-size: var(--fs-5);
  line-height: 1.8;
  color: var(--muted);
}

.page-about .about-hero__facts {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: clamp(14px, 3vw, 34px);
  margin: clamp(22px, 3vw, 34px) 0 0;
  padding: 16px 0 0;
  border-top: 1px solid var(--about-axis);
  font-size: var(--fs-7);
  color: var(--muted);
}

.page-about .about-hero__facts li {
  display: inline-flex;
  align-items: baseline;
  gap: 8px;
}

.page-about .about-hero__facts .mono {
  font-family: var(--font-mono);
  font-size: var(--fs-4);
  font-weight: 500;
  letter-spacing: .02em;
  color: var(--signal);
}

.page-about .about-hero__figure {
  margin: 0;
  overflow: hidden;
  border: 1px solid var(--line-steel);
  background: var(--deep);
  aspect-ratio: 4 / 3;
}

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

@media (min-width: 900px) {
  .page-about .about-hero__inner {
    grid-template-columns: minmax(0, 1.12fr) minmax(0, .88fr);
    align-items: stretch;
  }
  .page-about .about-hero__figure {
    aspect-ratio: auto;
    min-height: 100%;
  }
}

/* ---------- 章节时间轴 ---------- */
.page-about .chapters {
  position: relative;
  margin-top: clamp(20px, 4vw, 40px);
  padding-left: clamp(20px, 4vw, 36px);
}

.page-about .chapters::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 1px;
  background: linear-gradient(180deg,
    rgba(127, 227, 232, 0) 0,
    rgba(127, 227, 232, .34) 5%,
    rgba(127, 227, 232, .34) 95%,
    rgba(127, 227, 232, 0) 100%);
}

.page-about .chapter {
  position: relative;
  padding: clamp(26px, 4vw, 52px) 0;
}

.page-about .chapter::before {
  content: "";
  position: absolute;
  left: 0;
  top: clamp(34px, 5vw, 62px);
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--signal);
  box-shadow: 0 0 0 4px rgba(127, 227, 232, .12);
  transform: translateX(-50%);
}

.page-about .chapter__num {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .2em;
  color: var(--signal);
}

.page-about .chapter__title {
  margin: 0 0 clamp(14px, 2vw, 20px);
  font-size: var(--fs-2);
  font-weight: 800;
  line-height: 1.18;
  letter-spacing: -.01em;
  color: var(--text);
  max-width: 22ch;
}

.page-about .chapter__lead {
  margin: 0 0 clamp(20px, 3vw, 32px);
  max-width: 62ch;
  font-size: var(--fs-6);
  line-height: 1.85;
  color: var(--muted);
}

/* ---------- 三步对比 ---------- */
.page-about .steps {
  max-width: 76ch;
}

.page-about .step {
  border-top: 1px solid var(--about-axis);
  transition: background-color .18s ease-out;
}

.page-about .step:last-of-type {
  border-bottom: 1px solid var(--about-axis);
}

.page-about .step[open] {
  background: linear-gradient(90deg, rgba(18, 58, 87, .45), rgba(18, 58, 87, 0));
}

.page-about .step__head {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 16px 8px 16px 4px;
  cursor: pointer;
  list-style: none;
  color: var(--text);
}

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

.page-about .step__head::after {
  content: "+";
  margin-left: 14px;
  font-family: var(--font-mono);
  font-size: var(--fs-5);
  color: var(--signal);
  line-height: 1;
}

.page-about .step[open] .step__head::after {
  content: "−";
  color: var(--flare);
}

.page-about .step__idx {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .12em;
  color: var(--signal);
}

.page-about .step__title {
  font-size: var(--fs-4);
  font-weight: 700;
}

.page-about .step__hint {
  margin-left: auto;
  font-size: var(--fs-7);
  color: var(--muted);
  letter-spacing: .04em;
  white-space: nowrap;
}

.page-about .step__body {
  padding: 0 8px 20px 42px;
}

.page-about .step__body p {
  margin: 0;
  max-width: 60ch;
  font-size: var(--fs-6);
  line-height: 1.85;
  color: var(--muted);
}

/* ---------- 里程碑 ---------- */
.page-about .milestones {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 14px;
  max-width: 76ch;
}

.page-about .milestone {
  padding: 16px 18px;
  background: var(--about-card);
  border-left: 1px solid rgba(31, 127, 140, .9);
  transition: border-left-color .18s ease-out, background-color .18s ease-out;
}

.page-about .milestone:hover {
  border-left-color: var(--flare);
  background: rgba(18, 58, 87, .5);
}

.page-about .milestone__when {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--signal);
}

.page-about .milestone__name {
  margin: 0 0 6px;
  font-size: var(--fs-4);
  font-weight: 700;
  line-height: 1.35;
  color: var(--text);
}

.page-about .milestone__text {
  margin: 0;
  font-size: var(--fs-6);
  line-height: 1.8;
  color: var(--muted);
}

/* ---------- 团队 ---------- */
.page-about .team {
  display: grid;
  gap: clamp(18px, 3vw, 30px);
  max-width: 92ch;
}

.page-about .team__grid {
  display: grid;
  gap: 12px;
  grid-template-columns: minmax(0, 1fr);
}

.page-about .team__card {
  padding: 18px;
  border: 1px solid rgba(44, 79, 107, .75);
  background: var(--about-card);
}

.page-about .team__role {
  margin: 0 0 8px;
  font-size: var(--fs-7);
  letter-spacing: .1em;
  color: var(--signal);
}

.page-about .team__text {
  margin: 0;
  font-size: var(--fs-6);
  line-height: 1.8;
  color: var(--muted);
}

.page-about .team__figure {
  margin: 0;
  overflow: hidden;
  border: 1px solid var(--line-steel);
  background: var(--deep);
  aspect-ratio: 3 / 2;
}

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

@media (min-width: 700px) {
  .page-about .team__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

/* ---------- 服务网络 ---------- */
.page-about .net__banner {
  margin: 0 0 clamp(18px, 3vw, 28px);
  overflow: hidden;
  border: 1px solid var(--line-steel);
  background: var(--deep);
  aspect-ratio: 16 / 9;
}

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

.page-about .net__matrix {
  list-style: none;
  margin: 0 0 14px;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(32px, 1fr));
  gap: 5px;
}

.page-about .net__cell {
  aspect-ratio: 1;
  display: grid;
  place-items: center;
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--muted);
  border: 1px solid rgba(127, 227, 232, .16);
  background: rgba(31, 127, 140, .12);
}

.page-about .net__cell--mid {
  background: rgba(31, 127, 140, .34);
  color: var(--text);
  border-color: rgba(127, 227, 232, .26);
}

.page-about .net__cell--high {
  background: rgba(127, 227, 232, .38);
  color: var(--abyss);
  border-color: transparent;
  font-weight: 700;
}

.page-about .net__legend {
  display: flex;
  flex-wrap: wrap;
  gap: 16px;
  margin: 0 0 clamp(20px, 3vw, 30px);
  font-size: var(--fs-7);
  color: var(--muted);
}

.page-about .net__key {
  display: inline-flex;
  align-items: center;
  gap: 7px;
}

.page-about .net__swatch {
  width: 10px;
  height: 10px;
  display: inline-block;
  background: rgba(31, 127, 140, .12);
  border: 1px solid rgba(127, 227, 232, .16);
}

.page-about .net__swatch--mid {
  background: rgba(31, 127, 140, .34);
}

.page-about .net__swatch--high {
  background: rgba(127, 227, 232, .38);
  border-color: transparent;
}

.page-about .net__modes {
  display: grid;
  gap: 12px;
  grid-template-columns: minmax(0, 1fr);
  max-width: 88ch;
}

.page-about .net__mode {
  padding: 18px;
  border-top: 1px solid var(--about-axis);
  background: linear-gradient(180deg, rgba(18, 58, 87, .34), rgba(6, 24, 38, 0));
}

.page-about .net__mode-name {
  margin: 0 0 8px;
  font-size: var(--fs-4);
  font-weight: 700;
  color: var(--text);
}

.page-about .net__mode-text {
  margin: 0;
  font-size: var(--fs-6);
  line-height: 1.8;
  color: var(--muted);
}

@media (min-width: 760px) {
  .page-about .net__banner {
    aspect-ratio: 20 / 7;
  }
  .page-about .net__modes {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

/* ---------- 改进节奏 ---------- */
.page-about .cadence {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 0;
  max-width: 78ch;
}

.page-about .cadence__item {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 6px;
  padding: 16px 0;
  border-top: 1px solid var(--about-axis);
}

.page-about .cadence__item:last-child {
  border-bottom: 1px solid var(--about-axis);
}

.page-about .cadence__cycle {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--flare);
}

.page-about .cadence__name {
  margin: 0 0 6px;
  font-size: var(--fs-4);
  font-weight: 700;
  color: var(--text);
}

.page-about .cadence__body p {
  margin: 0;
  font-size: var(--fs-6);
  line-height: 1.8;
  color: var(--muted);
  max-width: 58ch;
}

@media (min-width: 760px) {
  .page-about .cadence__item {
    grid-template-columns: 120px minmax(0, 1fr);
    gap: 24px;
    align-items: start;
    padding: 20px 0;
  }
}

/* ---------- 资质与伙伴 ---------- */
.page-about .standing {
  display: grid;
  gap: 12px;
  grid-template-columns: minmax(0, 1fr);
  max-width: 92ch;
}

.page-about .standing__item {
  padding: 20px 18px;
  border: 1px solid rgba(44, 79, 107, .75);
  background: var(--about-card);
}

.page-about .standing__label {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--signal);
}

.page-about .standing__name {
  margin: 0 0 8px;
  font-size: var(--fs-4);
  font-weight: 700;
  line-height: 1.35;
  color: var(--text);
}

.page-about .standing__text {
  margin: 0;
  font-size: var(--fs-6);
  line-height: 1.8;
  color: var(--muted);
}

@media (min-width: 820px) {
  .page-about .standing {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }
}

/* ---------- 收束区 ---------- */
.page-about .about-next {
  margin-top: clamp(28px, 4vw, 56px);
  padding: clamp(28px, 4vw, 52px) 0;
  border-top: 1px solid var(--about-axis);
  background:
    linear-gradient(120deg, rgba(18, 58, 87, .55), rgba(6, 24, 38, 0) 72%),
    var(--abyss);
}

.page-about .about-next__inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(18px, 3vw, 30px);
  align-items: end;
}

.page-about .about-next__title {
  margin: 0 0 10px;
  font-size: var(--fs-3);
  font-weight: 800;
  line-height: 1.24;
  color: var(--text);
}

.page-about .about-next__text {
  margin: 0;
  max-width: 56ch;
  font-size: var(--fs-6);
  line-height: 1.8;
  color: var(--muted);
}

.page-about .about-next__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.page-about .about-next__links {
  list-style: none;
  margin: clamp(22px, 3vw, 34px) 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
  grid-template-columns: minmax(0, 1fr);
  font-size: var(--fs-6);
}

.page-about .about-next__links a {
  display: block;
  padding: 12px 0;
  border-top: 1px solid var(--about-axis);
  color: var(--text);
  text-decoration: none;
  transition: color .18s ease-out, padding-left .18s ease-out;
}

.page-about .about-next__links a:hover,
.page-about .about-next__links a:focus-visible {
  color: var(--signal);
  padding-left: 8px;
}

@media (min-width: 820px) {
  .page-about .about-next__inner {
    grid-template-columns: minmax(0, 1fr) auto;
  }
  .page-about .about-next__links {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 24px;
  }
}

/* ---------- 移动端保护 ---------- */
@media (max-width: 520px) {
  .page-about .step__hint {
    display: none;
  }
  .page-about .step__body {
    padding-left: 12px;
  }
  .page-about .net__matrix {
    grid-template-columns: repeat(auto-fill, minmax(28px, 1fr));
  }
  .page-about .net__cell {
    font-size: 10px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .milestone,
  .page-about .about-next__links a {
    transition: none;
  }
}
<<<END>>>