.page-about {
  --about-ro: 46rem;
  --about-node: 16px;
}

/* ---------- 面包屑与首屏 ---------- */
.page-about .crumb {
  padding-top: clamp(18px, 3vw, 34px);
}

.page-about .about-hero {
  padding-top: clamp(20px, 4vw, 44px);
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(30px, 5vw, 60px);
  align-items: center;
}

.page-about .about-hero h1 {
  margin: 14px 0 18px;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(30px, 5.4vw, 56px);
  line-height: 1.12;
  letter-spacing: -0.02em;
  color: var(--white);
}

.page-about .about-hero .lede {
  max-width: 56ch;
  color: var(--muted);
}

.page-about .hero-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: clamp(24px, 4vw, 34px) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .hero-chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 9px 14px;
  border: 1px solid var(--line);
  background-color: var(--panel);
  clip-path: var(--cut-sm);
  font-size: 0.86rem;
  color: var(--white);
}

.page-about .hero-chip .mono {
  color: var(--gold);
  font-size: 0.82rem;
}

.page-about .about-hero__viz {
  position: relative;
  padding: clamp(14px, 3vw, 26px);
  border: 1px solid var(--line);
  background-color: var(--panel);
  background-image:
    radial-gradient(120% 90% at 100% 0%, rgba(38, 226, 210, 0.16), transparent 62%),
    radial-gradient(110% 80% at 0% 100%, rgba(12, 110, 108, 0.4), transparent 60%);
  clip-path: var(--cut);
  overflow: hidden;
}

.page-about .about-hero__viz svg {
  display: block;
  width: 100%;
  height: auto;
}

.page-about .hv-grid {
  stroke: var(--line);
  stroke-width: 1;
  opacity: 0.55;
}

.page-about .hv-thin {
  stroke: var(--line);
  stroke-width: 1;
  stroke-dasharray: 4 8;
  fill: none;
}

.page-about .hv-node {
  fill: var(--ink);
  stroke: var(--cyan);
  stroke-width: 3;
}

.page-about .hv-label {
  fill: var(--gold);
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.06em;
}

/* ---------- 起点 ---------- */
.page-about .about-start__grid {
  align-items: start;
  gap: clamp(24px, 4vw, 48px);
}

.page-about .about-start__text p {
  margin: 0 0 14px;
  max-width: 54ch;
}

.page-about .about-start__text strong {
  color: var(--cyan);
  font-weight: 800;
}

.page-about .about-start__note {
  padding: clamp(20px, 3vw, 28px);
}

.page-about .about-start__note-title {
  margin: 0 0 16px;
  font-weight: 800;
  font-size: 1rem;
  color: var(--white);
}

.page-about .about-start__list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 12px;
}

.page-about .about-start__list li {
  display: grid;
  grid-template-columns: 46px 1fr;
  gap: 12px;
  align-items: baseline;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line);
  color: var(--muted);
  font-size: 0.95rem;
}

.page-about .about-start__list li:last-child {
  border-bottom: 0;
  padding-bottom: 0;
}

.page-about .about-start__list .mono {
  color: var(--gold);
  font-size: 0.95rem;
}

/* ---------- 三阶段时间轴 ---------- */
.page-about .about-stages__figure,
.page-about .about-stages__matrix {
  margin: clamp(30px, 5vw, 52px) 0 0;
}

.page-about .about-stages__matrix {
  margin-top: clamp(34px, 5vw, 60px);
}

.page-about .tl {
  position: relative;
  display: grid;
  gap: clamp(20px, 3vw, 34px);
  margin: clamp(32px, 5vw, 56px) 0 0;
  padding: 0;
  list-style: none;
}

.page-about .tl::before {
  content: "";
  position: absolute;
  left: 15px;
  top: 6px;
  bottom: 6px;
  width: 2px;
  background: linear-gradient(180deg, var(--cyan), var(--line) 55%, transparent);
}

.page-about .tl__item {
  position: relative;
  padding-left: 52px;
}

.page-about .tl__node {
  position: absolute;
  left: 8px;
  top: 24px;
  width: var(--about-node);
  height: var(--about-node);
  background-color: var(--ink);
  border: 2px solid var(--cyan);
  transform: rotate(45deg);
  z-index: 2;
  transition: background-color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .tl__item:has(.tl__card[open]) .tl__node {
  background-color: var(--cyan);
  border-color: var(--gold);
}

.page-about .tl__card {
  background-color: var(--panel);
  background-image: linear-gradient(90deg, transparent, rgba(38, 226, 210, 0.1), transparent);
  background-size: 220% 100%;
  background-repeat: no-repeat;
  background-position: 150% 0;
  border: 1px solid var(--line);
  clip-path: var(--cut);
  transition: border-color var(--dur) var(--ease), background-position .5s var(--ease);
}

.page-about .tl__card:hover,
.page-about .tl__card[open] {
  border-color: rgba(38, 226, 210, 0.55);
}

.page-about .tl__card:hover {
  background-position: -50% 0;
}

.page-about .tl__summary {
  display: grid;
  gap: 6px;
  padding: 20px 24px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .tl__stage {
  font-weight: 800;
  font-size: clamp(1.05rem, 1.6vw, 1.2rem);
  color: var(--white);
  letter-spacing: -0.01em;
}

.page-about .tl__meta {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  align-items: center;
}

.page-about .tl__code {
  padding: 3px 8px;
  border: 1px solid var(--line);
  color: var(--gold);
  font-size: 0.76rem;
  letter-spacing: 0.08em;
}

.page-about .tl__time {
  color: var(--muted);
  font-size: 0.76rem;
  letter-spacing: 0.08em;
}

.page-about .tl__more {
  margin-top: 4px;
  color: var(--cyan);
  font-size: 0.82rem;
}

.page-about .tl__more::before {
  content: "展开这一阶段的维护重点";
}

.page-about .tl__card[open] .tl__more::before {
  content: "收起";
}

.page-about .tl__body {
  padding: 4px 24px 22px;
  border-top: 1px solid var(--line);
  animation: about-fade var(--dur) var(--ease) both;
}

.page-about .tl__body p {
  margin: 16px 0 14px;
  color: var(--muted);
}

.page-about .tl__list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 10px;
}

.page-about .tl__list li {
  position: relative;
  padding-left: 18px;
  font-size: 0.95rem;
  color: var(--white);
}

.page-about .tl__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.62em;
  width: 8px;
  height: 2px;
  background-color: var(--cyan);
}

@keyframes about-fade {
  from { opacity: 0; transform: translateY(-4px); }
  to { opacity: 1; transform: none; }
}

/* ---------- 维护运转 ---------- */
.page-about .about-maint__grid {
  align-items: start;
  gap: clamp(26px, 4vw, 50px);
}

.page-about .facts {
  margin: 0 0 22px;
  display: grid;
  gap: 0;
}

.page-about .facts__row {
  display: grid;
  gap: 6px;
  padding: 14px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .facts__row:first-child {
  border-top: 1px solid var(--line);
}

.page-about .facts dt {
  font-size: 0.78rem;
  letter-spacing: 0.1em;
  color: var(--cyan);
  font-family: var(--font-mono);
  text-transform: uppercase;
}

.page-about .facts dd {
  margin: 0;
  color: var(--white);
  font-size: 0.98rem;
  line-height: 1.7;
}

.page-about .facts dd.mono {
  color: var(--gold);
  font-size: 1.05rem;
}

.page-about .about-maint__tail {
  margin: 0;
  padding-left: 16px;
  border-left: 2px solid var(--gold);
  color: var(--muted);
  font-size: 0.95rem;
}

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

/* ---------- 数据条带 + 增长图 ---------- */
.page-about .about-cover__band {
  margin-top: clamp(24px, 4vw, 40px);
}

.page-about .about-cover__band .band__track {
  display: flex;
  gap: 14px;
  margin: 0;
  padding: 6px var(--gutter) 22px;
  list-style: none;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-cover__band .band__item {
  flex: 0 0 auto;
  width: min(268px, 74vw);
  padding: 20px 22px;
  border: 1px solid var(--line);
  background-color: var(--panel);
  clip-path: var(--cut-sm);
  transition: border-color var(--dur) var(--ease), transform var(--dur) var(--ease);
}

.page-about .about-cover__band .band__item:hover {
  border-color: var(--cyan);
  transform: translateY(-4px);
}

.page-about .band__num {
  display: block;
  font-size: clamp(30px, 4.4vw, 42px);
  font-weight: 900;
  line-height: 1;
  color: var(--gold);
  letter-spacing: -0.02em;
}

.page-about .band__label {
  display: block;
  margin-top: 10px;
  font-weight: 700;
  color: var(--white);
}

.page-about .band__note {
  display: block;
  margin-top: 10px;
  font-size: 0.84rem;
  line-height: 1.65;
  color: var(--muted);
  transition: color var(--dur) var(--ease);
}

.page-about .about-cover__band .band__item:hover .band__note {
  color: var(--white);
}

.page-about .growth {
  display: grid;
  gap: clamp(24px, 4vw, 44px);
  margin-top: clamp(36px, 6vw, 64px);
  align-items: center;
}

.page-about .growth__text h3 {
  margin: 0 0 14px;
  font-size: clamp(1.25rem, 2.2vw, 1.6rem);
  font-weight: 800;
  color: var(--white);
}

.page-about .growth__text p {
  margin: 0 0 12px;
  max-width: 48ch;
  color: var(--muted);
}

.page-about .growth__fig {
  margin: 0;
  padding: clamp(14px, 2.4vw, 24px);
  border: 1px solid var(--line);
  background-color: var(--panel);
  background-image: radial-gradient(90% 70% at 80% 10%, rgba(38, 226, 210, 0.1), transparent 65%);
  clip-path: var(--cut);
}

.page-about .growth__fig svg {
  display: block;
  width: 100%;
  height: auto;
}

.page-about .growth__cap {
  margin-top: 10px;
  font-size: 0.78rem;
  letter-spacing: 0.06em;
  color: var(--muted);
  font-family: var(--font-mono);
}

.page-about .gx-axis {
  stroke: var(--line);
  stroke-width: 1.5;
}

.page-about .gx-grid {
  stroke: var(--line);
  stroke-width: 1;
  stroke-dasharray: 3 7;
  opacity: 0.7;
}

.page-about .gx-area {
  fill: rgba(38, 226, 210, 0.12);
  stroke: none;
}

.page-about .gx-line {
  fill: none;
  stroke: var(--cyan);
  stroke-width: 3;
  stroke-linecap: round;
  stroke-linejoin: round;
}

.page-about .gx-node {
  fill: var(--ink);
  stroke: var(--cyan);
  stroke-width: 3;
}

.page-about .gx-val {
  fill: var(--gold);
  font-family: var(--font-mono);
  font-size: 14px;
  font-weight: 700;
}

.page-about .gx-label {
  fill: var(--muted);
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.06em;
}

/* ---------- 结尾 ---------- */
.page-about .about-end {
  padding-bottom: clamp(56px, 8vw, 104px);
}

.page-about .about-end__inner {
  max-width: var(--about-ro);
  padding-left: clamp(18px, 3vw, 28px);
  border-left: 2px solid var(--line);
}

.page-about .about-end h2 {
  margin: 14px 0 20px;
  font-size: clamp(1.5rem, 3vw, 2.1rem);
  font-weight: 900;
  line-height: 1.25;
  letter-spacing: -0.015em;
  color: var(--white);
}

.page-about .about-end p {
  margin: 0 0 14px;
  color: var(--muted);
}

.page-about .about-end__legal {
  margin-top: 20px;
  padding-top: 16px;
  border-top: 1px dashed var(--line);
  font-size: 0.86rem;
}

.page-about .about-end__legal .mono {
  color: var(--gold);
  letter-spacing: 0.05em;
}

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

/* ---------- 响应式 ---------- */
@media (min-width: 760px) {
  .page-about .growth {
    grid-template-columns: 1fr 1.05fr;
  }

  .page-about .facts__row {
    grid-template-columns: 128px 1fr;
    gap: 18px;
    align-items: baseline;
  }
}

@media (min-width: 960px) {
  .page-about .about-hero__grid {
    grid-template-columns: 1.06fr 0.94fr;
  }
}

@media (min-width: 900px) {
  .page-about .tl::before {
    left: 50%;
    transform: translateX(-1px);
  }

  .page-about .tl__item {
    width: calc(50% - 44px);
    padding-left: 0;
  }

  .page-about .tl__item:nth-child(even) {
    margin-left: auto;
  }

  .page-about .tl__node {
    left: auto;
    right: -52px;
    top: 28px;
  }

  .page-about .tl__item:nth-child(even) .tl__node {
    left: -52px;
    right: auto;
  }
}
<<<END>>>