.page-about {
  --about-track-x: 9px;
  --about-track-offset: 34px;
  --about-node: var(--cyan);
}

/* ---------- Hero ---------- */
.page-about .about-hero {
  position: relative;
  padding: clamp(22px, 4vw, 40px) 0 clamp(34px, 6vw, 76px);
  background:
    radial-gradient(115% 85% at 86% -10%, rgba(47, 224, 200, 0.14), transparent 58%),
    radial-gradient(90% 70% at 8% 0%, rgba(154, 107, 255, 0.09), transparent 62%),
    linear-gradient(180deg, var(--ink-900), var(--ink-950));
  overflow: hidden;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image: repeating-linear-gradient(114deg, rgba(36, 52, 95, 0.34) 0 1px, transparent 1px 74px);
  opacity: 0.55;
  pointer-events: none;
}

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

.page-about .breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin-bottom: clamp(18px, 3vw, 30px);
  font-size: 13px;
  color: var(--fog);
  letter-spacing: 0.02em;
}

.page-about .breadcrumb a {
  color: var(--fog);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .breadcrumb a:hover,
.page-about .breadcrumb a:focus-visible {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

.page-about .breadcrumb span[aria-current] {
  color: var(--paper);
}

.page-about .about-hero__title {
  max-width: 22ch;
  margin: 0 0 clamp(16px, 2.4vw, 26px);
  font-size: clamp(30px, 6.4vw, 62px);
  font-weight: 900;
  line-height: 1.14;
  letter-spacing: -0.015em;
  color: var(--paper);
}

.page-about .about-hero__lead {
  max-width: 60ch;
  margin: 0 0 clamp(26px, 4vw, 46px);
  font-size: clamp(15px, 1.6vw, 17px);
  line-height: 1.78;
  color: var(--fog);
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 0;
  padding: 0;
  list-style: none;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
  border-radius: var(--r-md);
  overflow: hidden;
}

.page-about .about-stats__item {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: clamp(14px, 2.2vw, 22px) clamp(12px, 2vw, 20px);
  background: rgba(11, 18, 38, 0.92);
}

.page-about .about-stats__num {
  font-family: var(--font-mono);
  font-size: clamp(24px, 3.6vw, 34px);
  font-weight: 700;
  line-height: 1;
  color: var(--cyan);
  letter-spacing: -0.02em;
}

.page-about .about-stats__unit {
  margin-left: 2px;
  font-size: 0.55em;
  color: var(--fog);
}

.page-about .about-stats__label {
  font-size: 13px;
  line-height: 1.5;
  color: var(--fog);
}

/* ---------- 编年轨道 ---------- */
.page-about .about-lane {
  position: relative;
  background: linear-gradient(180deg, var(--ink-950), var(--ink-950));
}

.page-about .about-lane::before {
  content: "";
  position: absolute;
  left: var(--about-track-x);
  top: 0;
  bottom: 0;
  width: 1px;
  background: linear-gradient(180deg, transparent, var(--line) 4%, var(--line) 96%, transparent);
  pointer-events: none;
}

.page-about .about-block {
  position: relative;
  padding: clamp(34px, 6vw, 68px) 0 clamp(34px, 6vw, 68px) var(--about-track-offset);
}

.page-about .about-block::before {
  content: "";
  position: absolute;
  left: 4px;
  top: clamp(44px, 7vw, 78px);
  width: 11px;
  height: 11px;
  background: var(--ink-950);
  border: 1px solid var(--about-node);
  transform: rotate(45deg);
  transition: background var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}

.page-about .about-block:hover::before {
  background: var(--cyan);
  box-shadow: 0 0 0 4px rgba(47, 224, 200, 0.14);
}

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

.page-about .about-block .h2 {
  max-width: 26ch;
  margin: 0 0 clamp(14px, 2vw, 20px);
  font-size: clamp(24px, 3.6vw, 38px);
  font-weight: 800;
  line-height: 1.22;
  color: var(--paper);
}

.page-about .about-block__lead {
  max-width: 62ch;
  margin: 0 0 clamp(20px, 3vw, 32px);
  font-size: 16px;
  line-height: 1.78;
  color: var(--fog);
}

.page-about .about-block p {
  font-size: 16px;
  line-height: 1.78;
  color: var(--fog);
}

.page-about .about-block p + p {
  margin-top: 14px;
}

.page-about .about-block strong {
  color: var(--paper);
  font-weight: 700;
}

/* ---------- 图文错位 ---------- */
.page-about .about-split {
  display: grid;
  gap: clamp(22px, 4vw, 44px);
  align-items: start;
}

.page-about .about-split__figure {
  margin: 0;
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: var(--ink-800);
  overflow: hidden;
}

.page-about .about-split__figure img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  aspect-ratio: 16 / 10;
  object-fit: cover;
  filter: saturate(1.05) contrast(1.05);
}

.page-about .about-split__figure figcaption {
  padding: 12px 14px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--fog);
  border-top: 1px solid var(--line-soft);
}

.page-about .about-notes {
  display: grid;
  gap: 10px;
}

.page-about .note-card {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding: 14px 16px;
  background: var(--ink-800);
  border: 1px solid var(--line);
  border-left: 2px solid var(--yellow);
  border-radius: var(--r-sm);
}

.page-about .note-card__key {
  flex: 0 0 auto;
  min-width: 66px;
  font-family: var(--font-mono);
  font-size: 17px;
  font-weight: 700;
  color: var(--yellow);
}

.page-about .note-card__text {
  font-size: 14px;
  line-height: 1.65;
  color: var(--fog);
}

/* ---------- 流程面板 ---------- */
.page-about .flow-panel {
  position: relative;
  margin-bottom: clamp(22px, 3.6vw, 38px);
  padding: clamp(16px, 2.6vw, 30px);
  border: 1px solid var(--line);
  border-radius: var(--r-lg);
  background: var(--ink-900);
  overflow: hidden;
}

.page-about .flow-panel__figure {
  position: absolute;
  inset: 0;
  margin: 0;
  opacity: 0.16;
  pointer-events: none;
}

.page-about .flow-panel__figure img {
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
  filter: grayscale(0.4) contrast(1.2);
}

.page-about .flow-svg {
  position: relative;
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
}

/* ---------- 栏目折叠 ---------- */
.page-about .columns-list {
  display: grid;
  gap: 10px;
}

.page-about .column-item {
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: var(--ink-800);
  transition: border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .column-item:hover {
  border-color: var(--line);
  background: var(--ink-900);
}

.page-about .column-item[open] {
  border-color: rgba(47, 224, 200, 0.5);
  background: var(--ink-900);
}

.page-about .column-item__summary {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px 14px;
  padding: 15px 16px;
  cursor: pointer;
  list-style: none;
  outline: none;
}

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

.page-about .column-item__summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 18px;
  line-height: 1;
  color: var(--cyan);
  transition: transform var(--dur) var(--ease);
}

.page-about .column-item[open] .column-item__summary::after {
  content: "–";
}

.page-about .column-item__summary:focus-visible {
  outline: 2px solid var(--violet);
  outline-offset: -2px;
  border-radius: var(--r-md);
}

.page-about .column-item__idx {
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.08em;
  color: var(--yellow);
}

.page-about .column-item__name {
  font-size: 17px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .column-item__hint {
  font-size: 13px;
  color: var(--fog);
}

.page-about .column-item__body {
  padding: 0 16px 16px;
  border-top: 1px dashed var(--line);
  padding-top: 14px;
  margin: 0 16px 16px;
  padding-left: 0;
  padding-right: 0;
}

.page-about .column-item__body p {
  font-size: 15px;
  line-height: 1.78;
  color: var(--fog);
  margin: 0;
}

/* ---------- 团队比例图 ---------- */
.page-about .team-bars {
  display: grid;
  gap: 12px;
  margin: 0 0 clamp(22px, 3.4vw, 36px);
  padding: 0;
  list-style: none;
}

.page-about .team-bar {
  display: grid;
  grid-template-columns: 1fr auto;
  grid-template-areas:
    "label val"
    "track track";
  gap: 8px 12px;
  align-items: center;
}

.page-about .team-bar__label {
  grid-area: label;
  font-size: 14px;
  color: var(--paper);
}

.page-about .team-bar__val {
  grid-area: val;
  font-family: var(--font-mono);
  font-size: 17px;
  font-weight: 700;
  color: var(--cyan);
}

.page-about .team-bar__track {
  grid-area: track;
  display: block;
  height: 8px;
  background: var(--ink-800);
  border: 1px solid var(--line);
  border-radius: 999px;
  overflow: hidden;
}

.page-about .team-bar__fill {
  display: block;
  width: var(--bar, 0%);
  height: 100%;
  background: var(--fog);
  opacity: 0.7;
  transition: width 500ms var(--ease), opacity var(--dur) var(--ease);
}

.page-about .team-bar__fill--main {
  background: var(--cyan);
  opacity: 1;
}

.page-about .team-bar:hover .team-bar__fill {
  opacity: 1;
}

.page-about .about-side-note {
  padding: 20px 22px;
  border: 1px solid var(--line);
  border-radius: var(--r-md);
  background: var(--ink-800);
  box-shadow: 6px 6px 0 rgba(36, 52, 95, 0.55);
}

.page-about .about-side-note__title {
  margin: 0 0 10px;
  font-size: 17px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .about-side-note__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--fog);
}

/* ---------- 里程碑 ---------- */
.page-about .about-block--milestones {
  padding-bottom: clamp(40px, 7vw, 86px);
}

.page-about .milestones {
  display: grid;
  gap: clamp(18px, 3vw, 28px);
  margin: 0;
  padding: 0 6px 6px 0;
  list-style: none;
}

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

.page-about .milestone::after {
  content: "";
  position: absolute;
  left: 8px;
  top: 8px;
  right: 0;
  bottom: -8px;
  border: 1px solid var(--line-soft);
  border-radius: var(--r-md);
  pointer-events: none;
}

.page-about .milestone__card {
  position: relative;
  z-index: 1;
  padding: clamp(16px, 2.4vw, 24px) clamp(16px, 2.6vw, 26px);
  background: var(--ink-800);
  border: 1px solid var(--line);
  border-top: 2px solid var(--line);
  border-radius: var(--r-md);
  transition: border-color var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.page-about .milestone:hover .milestone__card {
  border-top-color: var(--cyan);
  transform: translateY(-2px);
}

.page-about .milestone__phase {
  display: inline-block;
  margin: 0 0 10px;
  padding: 3px 9px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--ink-950);
  background: var(--yellow);
  border-radius: var(--r-sm);
}

.page-about .milestone__card .h3 {
  margin: 0 0 8px;
  font-size: 19px;
  font-weight: 800;
  line-height: 1.35;
  color: var(--paper);
}

.page-about .milestone__card p {
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--fog);
}

/* ---------- 收束 ---------- */
.page-about .about-reasons {
  margin-bottom: clamp(22px, 3.4vw, 34px);
}

.page-about .reason-card {
  padding: clamp(16px, 2.4vw, 24px);
}

.page-about .reason-card__num {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--violet);
}

.page-about .reason-card .h3 {
  margin: 0 0 10px;
  font-size: 18px;
  font-weight: 800;
  line-height: 1.35;
  color: var(--paper);
}

.page-about .reason-card p {
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--fog);
}

.page-about .about-cta {
  padding: clamp(20px, 3.2vw, 32px);
  border: 1px solid var(--line);
  border-left: 3px solid var(--orange);
  border-radius: var(--r-md);
  background: linear-gradient(135deg, var(--ink-800), var(--ink-900));
}

.page-about .about-cta__text {
  max-width: 64ch;
  margin: 0 0 clamp(16px, 2.4vw, 24px);
  font-size: 16px;
  line-height: 1.78;
  color: var(--fog);
}

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

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .about-block {
    --about-track-x: 11px;
    --about-track-offset: 48px;
  }

  .page-about .about-block::before {
    left: 6px;
  }

  .page-about .about-lane::before {
    left: 11px;
  }

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

  .page-about .about-split {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
  }

  .page-about .about-split--reverse {
    grid-template-columns: minmax(0, 0.95fr) minmax(0, 1.05fr);
  }

  .page-about .about-split--reverse > .about-split__text {
    order: 2;
  }

  .page-about .about-notes {
    align-content: start;
  }

  .page-about .team-bar {
    grid-template-columns: minmax(150px, 200px) minmax(0, 1fr) 48px;
    grid-template-areas: "label track val";
    gap: 14px;
  }

  .page-about .team-bar__val {
    text-align: right;
  }

  .page-about .milestones {
    padding-right: clamp(20px, 6vw, 90px);
  }

  .page-about .milestone:nth-child(even) {
    margin-left: clamp(28px, 9%, 120px);
  }

  .page-about .milestone:nth-child(odd) {
    margin-right: clamp(28px, 9%, 120px);
  }
}

@media (min-width: 1024px) {
  .page-about .about-block {
    --about-track-x: 15px;
    --about-track-offset: 72px;
  }

  .page-about .about-block::before {
    left: 10px;
  }

  .page-about .about-lane::before {
    left: 15px;
  }

  .page-about .about-hero__shell {
    padding-right: clamp(0px, 6vw, 120px);
  }

  .page-about .flow-panel {
    padding: clamp(24px, 3vw, 40px);
  }

  .page-about .column-item__summary {
    padding: 18px 22px;
  }

  .page-about .column-item__body {
    margin: 0 22px 20px;
    padding-top: 16px;
  }
}
>>>

.page-about {
  --bar: 1rem;
}