.page-about {
  --about-node: 13px;
  --about-gutter-line: 6px;
}

/* ---------- 首屏 ---------- */
.page-about .about-intro {
  padding-top: 28px;
}

.page-about .about-intro__title {
  margin: 16px 0 0;
  max-width: 17ch;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(30px, 5.4vw, 58px);
  line-height: 1.14;
  letter-spacing: -0.01em;
  color: var(--cold);
}

.page-about .about-intro__lede {
  margin: 22px 0 0;
  max-width: 62ch;
  font-size: 17px;
  line-height: 1.8;
  color: var(--silver);
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 40px 0 0;
  padding: 0;
  list-style: none;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
  border-radius: var(--r-m);
  overflow: hidden;
}

.page-about .about-stat {
  background: var(--ink-800);
  padding: 18px 18px 20px;
}

.page-about .about-stat__value {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(24px, 4vw, 32px);
  line-height: 1;
  color: var(--cold);
}

.page-about .about-stat__unit {
  margin-left: 4px;
  font-size: 13px;
  color: var(--amber);
}

.page-about .about-stat__label {
  display: block;
  margin-top: 10px;
  font-size: 13px;
  letter-spacing: 0.02em;
  color: var(--silver);
}

/* ---------- 起点 ---------- */
.page-about .about-origin__note {
  align-self: start;
  padding: 24px;
  background: var(--panel);
  border: 1px solid var(--line-soft);
  border-radius: var(--r-m);
  box-shadow: var(--shadow-card);
}

.page-about .about-origin__note-title {
  margin: 0 0 14px;
  font-size: 15px;
  letter-spacing: 0.04em;
  color: var(--cold);
}

.page-about .about-origin__list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-origin__list li {
  position: relative;
  padding: 9px 0 9px 18px;
  font-size: 14px;
  line-height: 1.65;
  color: var(--silver);
  border-top: 1px solid var(--line-soft);
}

.page-about .about-origin__list li:first-child {
  border-top: 0;
}

.page-about .about-origin__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 17px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--night);
  opacity: 0.75;
}

/* ---------- 时间轴 ---------- */
.page-about .about-timeline {
  position: relative;
  overflow: hidden;
}

.page-about .about-timeline__visual {
  position: absolute;
  inset: 0;
  z-index: 0;
  margin: 0;
  opacity: 0.13;
  pointer-events: none;
  -webkit-mask-image: radial-gradient(120% 78% at 82% 4%, #000 0%, transparent 74%);
  mask-image: radial-gradient(120% 78% at 82% 4%, #000 0%, transparent 74%);
}

.page-about .about-timeline__visual img {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.page-about .about-timeline > .shell {
  position: relative;
  z-index: 1;
}

.page-about .about-timeline__lede {
  max-width: 54ch;
  margin-top: 16px;
  color: var(--silver);
}

.page-about .about-track {
  position: relative;
  margin-top: 44px;
  padding-left: 40px;
}

.page-about .about-track::before {
  content: "";
  position: absolute;
  left: var(--about-gutter-line);
  top: 18px;
  bottom: 18px;
  width: 1px;
  background: linear-gradient(180deg,
    rgba(79, 166, 255, 0) 0%,
    var(--line) 10%,
    var(--line) 90%,
    rgba(79, 166, 255, 0) 100%);
}

.page-about .about-track__item {
  position: relative;
  padding: 26px 0;
  border-top: 1px solid var(--line-soft);
}

.page-about .about-track__item:first-child {
  border-top: 0;
  padding-top: 6px;
}

.page-about .about-track__item::before {
  content: "";
  position: absolute;
  left: -40px;
  top: 30px;
  width: var(--about-node);
  height: var(--about-node);
  border-radius: 50%;
  background: var(--ink-900);
  border: 1px solid var(--line);
  transition:
    background-color var(--dur-base) var(--ease),
    border-color var(--dur-base) var(--ease),
    box-shadow var(--dur-base) var(--ease);
}

.page-about .about-track__item.is-visible::before {
  background: var(--amber);
  border-color: var(--amber);
  box-shadow: 0 0 0 4px rgba(227, 167, 58, 0.14);
}

.page-about .about-track__when {
  display: flex;
  align-items: baseline;
  gap: 10px;
  margin-bottom: 10px;
}

.page-about .about-track__year {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 20px;
  line-height: 1;
  letter-spacing: 0.02em;
  color: var(--amber);
}

.page-about .about-track__phase {
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--cyan);
  border: 1px solid rgba(111, 227, 210, 0.32);
  border-radius: var(--r-pill);
  padding: 3px 10px;
}

.page-about .about-track__body h3 {
  margin: 0 0 10px;
  font-size: 19px;
  line-height: 1.45;
  color: var(--cold);
}

.page-about .about-track__body p {
  margin: 0;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.85;
  color: var(--silver);
}

.page-about .about-track__body a {
  color: var(--night);
  text-decoration: none;
  border-bottom: 1px solid rgba(79, 166, 255, 0.35);
}

.page-about .about-track__body a:hover {
  border-bottom-color: var(--night);
}

.page-about .about-track__breathe {
  padding: 26px 0 22px;
}

.page-about .about-track__breathe p {
  margin: 0;
  max-width: 24ch;
  font-family: var(--font-display);
  font-size: clamp(19px, 3.4vw, 28px);
  font-weight: 500;
  line-height: 1.42;
  color: var(--cold);
  padding-left: 18px;
  border-left: 2px solid var(--amber);
}

/* ---------- 交付流程手风琴 ---------- */
.page-about .about-delivery .lede {
  max-width: 56ch;
  color: var(--silver);
}

.page-about .about-delivery .accordion {
  margin-top: 26px;
}

.page-about .about-step__no {
  display: inline-block;
  min-width: 2.2em;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--amber);
}

.page-about .about-step__name {
  font-size: 16px;
  color: var(--cold);
}

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

.page-about .about-delivery .accordion__panel p {
  margin: 0;
  font-size: 14px;
  line-height: 1.85;
  color: var(--silver);
}

/* ---------- 定制流程 ---------- */
.page-about .about-custom__lede {
  max-width: 56ch;
  color: var(--silver);
}

.page-about .about-flow {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  margin: 32px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .about-flow__step {
  position: relative;
  padding: 22px 20px 24px;
  background: var(--panel);
  border: 1px solid var(--line-soft);
  border-radius: var(--r-m);
  box-shadow: var(--shadow-card);
  transition:
    border-color var(--dur-fast) var(--ease),
    transform var(--dur-fast) var(--ease);
}

.page-about .about-flow__step::after {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 2px;
  border-radius: var(--r-m) 0 0 var(--r-m);
  background: linear-gradient(180deg, var(--amber), rgba(227, 167, 58, 0));
  opacity: 0.85;
}

.page-about .about-flow__step:hover {
  border-color: rgba(227, 167, 58, 0.45);
  transform: translateY(-2px);
}

.page-about .about-flow__no {
  display: block;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--amber);
}

.page-about .about-flow__title {
  margin: 10px 0 8px;
  font-size: 17px;
  line-height: 1.4;
  color: var(--cold);
}

.page-about .about-flow__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--silver);
}

.page-about .about-custom__more {
  margin: 26px 0 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--silver);
}

.page-about .about-custom__more a {
  color: var(--night);
  text-decoration: none;
  border-bottom: 1px solid rgba(79, 166, 255, 0.35);
}

.page-about .about-custom__more a:hover {
  border-bottom-color: var(--night);
}

/* ---------- 合作生态 ---------- */
.page-about .about-eco__grid {
  margin-top: 30px;
}

.page-about .about-eco__sub {
  margin: 0 0 16px;
  font-size: 17px;
  line-height: 1.5;
  color: var(--cold);
}

.page-about .about-creds {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

.page-about .about-cred {
  padding: 22px;
  border: 1px solid var(--line);
  border-radius: var(--r-m);
  background:
    linear-gradient(158deg, rgba(79, 166, 255, 0.07) 0%, rgba(79, 166, 255, 0) 58%),
    var(--panel);
  box-shadow: var(--shadow-card);
  transition:
    border-color var(--dur-base) var(--ease),
    box-shadow var(--dur-base) var(--ease);
}

.page-about .about-cred:hover,
.page-about .about-cred:focus-within,
.page-about .about-cred:focus {
  border-color: rgba(227, 167, 58, 0.55);
  box-shadow: var(--shadow-card), 0 0 0 1px rgba(227, 167, 58, 0.18);
}

.page-about .about-cred__title {
  margin: 12px 0 8px;
  font-size: 16px;
  line-height: 1.45;
  color: var(--cold);
}

.page-about .about-cred__brief {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--silver);
}

.page-about .about-cred__extra {
  max-height: 0;
  opacity: 0;
  overflow: hidden;
  transition:
    max-height var(--dur-base) var(--ease),
    opacity var(--dur-base) var(--ease),
    margin-top var(--dur-base) var(--ease);
}

.page-about .about-cred:hover .about-cred__extra,
.page-about .about-cred:focus-within .about-cred__extra,
.page-about .about-cred:focus .about-cred__extra {
  max-height: 300px;
  opacity: 1;
  margin-top: 14px;
}

.page-about .about-cred__extra p {
  margin: 0;
  padding-top: 14px;
  border-top: 1px solid var(--line-soft);
  font-size: 13px;
  line-height: 1.8;
  color: var(--silver);
}

/* ---------- 服务网络 ---------- */
.page-about .about-network__figure {
  margin: 30px 0 0;
}

/* ---------- 合规条 ---------- */
.page-about .about-legal__bar {
  display: grid;
  gap: 22px;
  padding: 28px 24px;
  border: 1px solid var(--line-soft);
  border-radius: var(--r-l);
  background:
    linear-gradient(120deg, rgba(227, 167, 58, 0.08) 0%, rgba(227, 167, 58, 0) 46%),
    var(--panel);
}

.page-about .about-legal__title {
  margin: 12px 0 10px;
  font-size: 22px;
  line-height: 1.35;
  color: var(--cold);
}

.page-about .about-legal__text {
  margin: 0;
  max-width: 58ch;
  font-size: 14px;
  line-height: 1.8;
  color: var(--silver);
}

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

/* ---------- 平板 ---------- */
@media (min-width: 680px) {
  .page-about .about-stats {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-flow {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 16px;
  }
}

/* ---------- 桌面 ---------- */
@media (min-width: 900px) {
  .page-about .about-intro {
    padding-top: 44px;
  }

  .page-about .about-intro__lede {
    font-size: 18px;
  }

  .page-about .about-stats {
    grid-template-columns: repeat(5, minmax(0, 1fr));
    margin-top: 52px;
  }

  .page-about .about-stat {
    padding: 22px 20px 24px;
  }

  .page-about .about-track {
    padding-left: 48px;
    margin-top: 56px;
  }

  .page-about .about-track::before {
    left: var(--about-gutter-line);
  }

  .page-about .about-track__item {
    display: grid;
    grid-template-columns: 190px minmax(0, 1fr);
    gap: 48px;
    align-items: start;
    padding: 34px 0;
  }

  .page-about .about-track__item:first-child {
    padding-top: 8px;
  }

  .page-about .about-track__item::before {
    left: -48px;
    top: 42px;
  }

  .page-about .about-track__item:first-child::before {
    top: 16px;
  }

  .page-about .about-track__when {
    flex-direction: column;
    align-items: flex-start;
    gap: 8px;
    margin-bottom: 0;
  }

  .page-about .about-track__breathe {
    padding: 34px 0 30px;
  }

  .page-about .about-track__breathe p {
    max-width: 30ch;
  }

  .page-about .about-delivery__figure {
    margin: 8px 0 0;
  }

  .page-about .about-flow {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 18px;
    margin-top: 38px;
  }

  .page-about .about-network__figure {
    margin: 6px 0 0;
  }

  .page-about .about-legal__bar {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    gap: 40px;
    padding: 34px 36px;
  }

  .page-about .about-legal__actions {
    justify-content: flex-end;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-flow__step:hover {
    transform: none;
  }

  .page-about .about-track__item::before {
    transition: background-color var(--dur-base) var(--ease),
      border-color var(--dur-base) var(--ease);
  }
}