.page-about {
  --about-railw: 220px;
  --about-cut: 16px;
  display: block;
  background: var(--c-abyss);
  color: var(--c-white);
  overflow-x: hidden;
}

/* ---------- 首屏框景 ---------- */
.page-about .about-masthead {
  position: relative;
  border-bottom: 1px solid var(--line-soft);
  background:
    radial-gradient(120% 80% at 12% 0%, rgba(18, 58, 87, .9) 0%, rgba(4, 18, 31, 0) 62%),
    var(--c-abyss);
}

.page-about .about-masthead__text {
  padding-block: 28px 30px;
}

.page-about .about-masthead .crumbs ol {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0 0 20px;
  padding: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .1em;
  color: var(--c-silver);
}

.page-about .about-masthead .crumbs li + li::before {
  content: "/";
  margin-right: 8px;
  color: rgba(143, 163, 176, .6);
}

.page-about .about-masthead .crumbs a {
  color: var(--c-silver);
  text-decoration: none;
  border-bottom: 1px solid transparent;
  transition: color .2s var(--ease), border-color .2s var(--ease);
}

.page-about .about-masthead .crumbs a:hover {
  color: var(--c-glow);
  border-bottom-color: var(--c-glow);
}

.page-about .about-masthead .eyebrow {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--c-cyan);
  padding-left: 12px;
  border-left: 2px solid var(--c-glow);
}

.page-about h1 {
  margin: 0;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(28px, 6.6vw, 58px);
  line-height: 1.14;
  letter-spacing: -.015em;
  max-width: 20ch;
  background: linear-gradient(100deg, var(--c-white) 58%, var(--c-glow) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.page-about .about-masthead__lead {
  margin: 20px 0 0;
  max-width: 62ch;
  font-size: clamp(15px, 3.4vw, 17px);
  line-height: 1.85;
  color: rgba(247, 251, 255, .76);
}

.page-about .about-masthead__figure {
  position: relative;
  margin: 0;
  border-top: 1px solid var(--line-glow);
  border-bottom: 1px solid var(--line-glow);
  overflow: hidden;
}

.page-about .about-masthead__figure::after {
  content: "";
  position: absolute;
  inset: 0;
  background:
    linear-gradient(180deg, rgba(4, 18, 31, .55) 0%, rgba(4, 18, 31, .05) 40%, rgba(4, 18, 31, .8) 100%),
    repeating-linear-gradient(115deg, rgba(111, 243, 224, .05) 0 1px, transparent 1px 34px);
  pointer-events: none;
}

.page-about .about-masthead__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 16 / 9;
  object-fit: cover;
}

.page-about .about-masthead__cap {
  position: absolute;
  left: 15px;
  bottom: 12px;
  z-index: 2;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  color: var(--c-glow);
}

.page-about .about-masthead__ticker {
  background: var(--c-deep);
}

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

.page-about .about-tick {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 13px 14px;
  border-bottom: 1px solid var(--line-soft);
  border-right: 1px solid var(--line-soft);
}

.page-about .about-tick b {
  font-family: var(--font-mono);
  font-size: 19px;
  line-height: 1;
  color: var(--c-amber);
  letter-spacing: .02em;
}

.page-about .about-tick i {
  font-style: normal;
  font-size: 12px;
  letter-spacing: .06em;
  color: var(--c-silver);
}

/* ---------- 正文骨架：窄注释栏 + 宽正文 ---------- */
.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
}

.page-about .about-rail {
  display: none;
}

.page-about .about-main {
  min-width: 0;
}

.page-about .about-sec {
  padding-block: 44px;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-sec:last-child {
  border-bottom: 0;
}

.page-about .about-sec__index {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin: 0 0 16px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--c-silver);
}

.page-about .about-sec__index::before {
  content: "";
  width: 2px;
  height: 14px;
  background: var(--c-glow);
}

.page-about .about-sec__index span {
  color: var(--c-glow);
}

.page-about h2 {
  margin: 0 0 20px;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(22px, 5vw, 36px);
  line-height: 1.24;
  letter-spacing: -.01em;
  color: var(--c-white);
  max-width: 24ch;
}

.page-about h3 {
  margin: 0 0 8px;
  font-size: 16px;
  font-weight: 600;
  color: var(--c-white);
}

.page-about p {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.85;
  color: rgba(247, 251, 255, .78);
  max-width: 68ch;
}

.page-about p + p {
  margin-top: 16px;
}

.page-about a {
  color: var(--c-cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(35, 199, 180, .4);
  transition: color .2s var(--ease), border-color .2s var(--ease);
}

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

.page-about .about-sec__foot {
  margin-top: 24px;
  font-size: 14px;
  color: var(--c-silver);
}

/* ---------- 适合谁 ---------- */
.page-about .about-who {
  list-style: none;
  margin: 30px 0 0;
  padding: 0;
  border-top: 1px solid var(--line-soft);
}

.page-about .about-who li {
  padding: 16px 14px 16px 18px;
  border-bottom: 1px solid var(--line-soft);
  border-left: 2px solid transparent;
  font-size: 15px;
  line-height: 1.78;
  color: rgba(247, 251, 255, .78);
  transition: border-color .22s var(--ease), background .22s var(--ease);
}

.page-about .about-who li:hover {
  border-left-color: var(--c-glow);
  background: rgba(18, 58, 87, .45);
}

.page-about .about-who b {
  color: var(--c-glow);
  font-weight: 600;
  margin-right: 8px;
}

/* ---------- 团队分栏 ---------- */
.page-about .about-split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 26px;
  align-items: start;
}

.page-about .about-split__fig {
  margin: 0;
  border: 1px solid var(--line-soft);
  border-left: 2px solid var(--c-cyan);
  background: var(--c-deep);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--about-cut)), calc(100% - var(--about-cut)) 100%, 0 100%);
}

.page-about .about-split__fig img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 1 / 1;
  object-fit: cover;
  opacity: .9;
}

.page-about .about-split__fig figcaption {
  padding: 10px 14px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--c-silver);
  border-top: 1px solid var(--line-soft);
}

.page-about .about-team-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin-top: 28px;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
}

.page-about .about-team-card {
  background: var(--c-deep);
  padding: 20px 18px 22px;
  transition: background .24s var(--ease);
}

.page-about .about-team-card:hover {
  background: var(--c-mid);
}

.page-about .about-team-card__no {
  display: block;
  font-family: var(--font-mono);
  font-size: 30px;
  line-height: 1;
  color: var(--c-glow);
  margin-bottom: 12px;
  letter-spacing: -.02em;
}

.page-about .about-team-card p {
  font-size: 14px;
  line-height: 1.75;
  color: rgba(247, 251, 255, .68);
}

/* ---------- 流程 ---------- */
.page-about .about-flow-scroll {
  margin: 26px 0 8px;
  overflow-x: auto;
  border: 1px solid var(--line-soft);
  background:
    repeating-linear-gradient(90deg, rgba(143, 163, 176, .07) 0 1px, transparent 1px 24px),
    var(--c-abyss);
  padding: 12px 8px;
  -webkit-overflow-scrolling: touch;
}

.page-about .about-flow {
  display: block;
  width: 100%;
  min-width: 520px;
  height: auto;
}

.page-about .about-flow-fig {
  margin: 24px 0 0;
  border: 1px solid var(--line-soft);
}

.page-about .about-flow-fig img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  opacity: .88;
}

.page-about .about-steps {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line-soft);
}

.page-about .about-step {
  position: relative;
  background: var(--c-deep);
  padding: 20px 18px 22px 68px;
  transition: background .24s var(--ease);
}

.page-about .about-step:hover {
  background: var(--c-mid);
}

.page-about .about-step__num {
  position: absolute;
  left: 18px;
  top: 22px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .1em;
  color: var(--c-hot);
}

.page-about .about-step__num::after {
  content: "";
  position: absolute;
  left: 0;
  top: 22px;
  width: 26px;
  height: 2px;
  background: var(--c-amber);
}

.page-about .about-step p {
  font-size: 14.5px;
  line-height: 1.8;
  color: rgba(247, 251, 255, .72);
}

.page-about .about-callout {
  margin-top: 28px;
  padding: 22px 20px;
  background: rgba(255, 90, 43, .08);
  border-left: 2px solid var(--c-hot);
  display: grid;
  gap: 4px;
}

.page-about .about-callout__k {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--c-amber);
}

.page-about .about-callout__v {
  font-size: 16px;
  line-height: 1.7;
  color: var(--c-white);
  font-weight: 500;
}

.page-about .about-callout__k:not(:first-child) {
  margin-top: 12px;
}

.page-about .about-callout__note {
  margin-top: 14px;
  padding-top: 14px;
  border-top: 1px dashed rgba(255, 180, 58, .3);
  font-size: 13.5px;
  line-height: 1.75;
  color: rgba(247, 251, 255, .7);
}

/* ---------- 资料类型 ---------- */
.page-about .about-kinds {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
}

.page-about .about-kind {
  background: var(--c-deep);
  padding: 18px 18px 20px;
  transition: background .24s var(--ease);
}

.page-about .about-kind:hover {
  background: var(--c-mid);
}

.page-about .about-kind__no {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .16em;
  color: var(--c-cyan);
  margin-bottom: 10px;
  padding-bottom: 10px;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-kind p {
  font-size: 14px;
  line-height: 1.75;
  color: rgba(247, 251, 255, .68);
}

.page-about .about-formats {
  margin-top: 26px;
  padding: 20px 0 0;
  border-top: 1px solid var(--line-soft);
}

.page-about .about-formats__lead {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: .14em;
  color: var(--c-silver);
  margin-bottom: 14px;
}

.page-about .about-formats ul {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 8px;
}

.page-about .about-formats li {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 12px 14px;
  background: var(--c-deep);
  border-left: 2px solid var(--c-mid);
  font-size: 14px;
  color: rgba(247, 251, 255, .74);
}

.page-about .about-formats b {
  font-family: var(--font-mono);
  font-size: 14px;
  letter-spacing: .08em;
  color: var(--c-amber);
  min-width: 52px;
}

/* ---------- 版本时间轴 ---------- */
.page-about .about-timeline {
  list-style: none;
  margin: 30px 0 0;
  padding: 0 0 0 26px;
  position: relative;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 10px;
  bottom: 10px;
  width: 2px;
  background: linear-gradient(180deg, var(--c-glow) 0%, rgba(35, 199, 180, .5) 55%, rgba(35, 199, 180, .1) 100%);
}

.page-about .about-tl {
  position: relative;
  margin-bottom: 12px;
}

.page-about .about-tl:last-child {
  margin-bottom: 0;
}

.page-about .about-tl::before {
  content: "";
  position: absolute;
  left: -24px;
  top: 20px;
  width: 8px;
  height: 8px;
  background: var(--c-abyss);
  border: 2px solid var(--c-glow);
  transform: rotate(45deg);
}

.page-about .about-tl__item {
  background: var(--c-deep);
  border-left: 2px solid var(--c-mid);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--about-cut)), calc(100% - var(--about-cut)) 100%, 0 100%);
  transition: background .26s var(--ease), border-color .26s var(--ease);
}

.page-about .about-tl__item:hover {
  border-left-color: var(--c-cyan);
  background: var(--c-mid);
}

.page-about .about-tl__item[open] {
  border-left-color: var(--c-glow);
  background: var(--c-mid);
}

.page-about .about-tl__item summary {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 17px 18px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .about-tl__item summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 17px;
  line-height: 1;
  color: var(--c-cyan);
}

.page-about .about-tl__item[open] summary::after {
  content: "–";
  color: var(--c-glow);
}

.page-about .about-tl__ver {
  font-family: var(--font-mono);
  font-size: 15px;
  letter-spacing: .1em;
  color: var(--c-amber);
  flex: 0 0 auto;
}

.page-about .about-tl__name {
  font-size: 15px;
  font-weight: 600;
  color: var(--c-white);
}

.page-about .about-tl__body {
  padding: 0 18px 18px;
}

.page-about .about-tl__body p {
  padding-top: 14px;
  border-top: 1px dashed var(--line-soft);
  font-size: 14.5px;
  line-height: 1.8;
  color: rgba(247, 251, 255, .74);
}

/* ---------- 合作数字带 ---------- */
.page-about .about-stat-band {
  margin-top: 30px;
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  background: var(--line-soft);
  border-block: 1px solid var(--line-glow);
}

.page-about .about-stat {
  background: var(--c-abyss);
  padding: 22px 14px 20px;
  text-align: center;
}

.page-about .about-stat__num {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: clamp(28px, 8vw, 42px);
  line-height: 1;
  color: var(--c-amber);
  letter-spacing: -.02em;
}

.page-about .about-stat__unit {
  display: inline-block;
  margin-left: 5px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: .1em;
  color: var(--c-silver);
}

.page-about .about-stat p {
  margin: 12px auto 0;
  font-size: 12px;
  line-height: 1.6;
  letter-spacing: .04em;
  color: var(--c-silver);
  max-width: 14ch;
}

/* ---------- 服务承诺 ---------- */
.page-about .about-assure {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line-soft);
  border: 1px solid var(--line-soft);
}

.page-about .about-assure li {
  background: var(--c-deep);
  padding: 16px 18px;
  font-size: 14px;
  line-height: 1.75;
  color: rgba(247, 251, 255, .74);
  border-left: 2px solid transparent;
  transition: border-color .22s var(--ease), background .22s var(--ease);
}

.page-about .about-assure li:hover {
  border-left-color: var(--c-glow);
  background: var(--c-mid);
}

.page-about .about-assure b {
  display: inline-block;
  min-width: 5.2em;
  color: var(--c-cyan);
  font-weight: 600;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .06em;
}

/* ---------- 底部行动 ---------- */
.page-about .about-cta {
  background:
    linear-gradient(115deg, var(--c-mid) 0%, var(--c-deep) 46%, var(--c-abyss) 100%);
  border-top: 1px solid var(--line-glow);
  position: relative;
  overflow: hidden;
}

.page-about .about-cta::before {
  content: "";
  position: absolute;
  inset: 0;
  background: repeating-linear-gradient(72deg, rgba(111, 243, 224, .06) 0 1px, transparent 1px 46px);
  pointer-events: none;
}

.page-about .about-cta__inner {
  position: relative;
  padding-block: 40px;
  display: grid;
  gap: 22px;
  align-items: center;
}

.page-about .about-cta h2 {
  font-size: clamp(20px, 5vw, 30px);
  margin: 0 0 10px;
  max-width: 20ch;
}

.page-about .about-cta p {
  font-size: 14.5px;
  color: rgba(247, 251, 255, .72);
}

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

/* ---------- 平板 ---------- */
@media (min-width: 640px) {
  .page-about .about-masthead__ticker-inner {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-tick {
    border-bottom: 0;
  }

  .page-about .about-tick:last-child {
    border-right: 0;
  }

  .page-about .about-who li {
    display: flex;
    gap: 4px;
  }

  .page-about .about-team-grid {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

  .page-about .about-formats ul {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

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

/* ---------- 桌面：窄注释栏 + 宽正文 ---------- */
@media (min-width: 960px) {
  .page-about .about-masthead__text {
    padding-block: 44px 38px;
  }

  .page-about .about-body {
    grid-template-columns: var(--about-railw) minmax(0, 1fr);
    gap: 52px;
    align-items: start;
  }

  .page-about .about-rail {
    display: block;
    position: sticky;
    top: 96px;
    padding-block: 48px;
    border-right: 1px solid var(--line-soft);
    padding-right: 20px;
  }

  .page-about .about-rail__title {
    margin: 0 0 14px;
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: .2em;
    text-transform: uppercase;
    color: var(--c-silver);
  }

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

  .page-about .about-rail__list a {
    display: flex;
    align-items: baseline;
    gap: 10px;
    padding: 9px 0 9px 12px;
    border-left: 2px solid transparent;
    border-bottom: 0;
    font-size: 13.5px;
    line-height: 1.5;
    color: var(--c-silver);
    transition: color .22s var(--ease), border-color .22s var(--ease), padding-left .22s var(--ease);
  }

  .page-about .about-rail__list a em {
    font-style: normal;
    font-family: var(--font-mono);
    font-size: 11px;
    letter-spacing: .08em;
    color: rgba(143, 163, 176, .7);
  }

  .page-about .about-rail__list a:hover,
  .page-about .about-rail__list a.is-active {
    color: var(--c-glow);
    border-left-color: var(--c-glow);
    padding-left: 18px;
  }

  .page-about .about-rail__list a:hover em,
  .page-about .about-rail__list a.is-active em {
    color: var(--c-cyan);
  }

  .page-about .about-rail__facts {
    margin-top: 28px;
    padding-top: 20px;
    border-top: 1px solid var(--line-soft);
  }

  .page-about .about-rail__facts p {
    display: flex;
    flex-direction: column;
    gap: 3px;
    margin: 0 0 14px;
    padding-left: 10px;
    border-left: 2px solid var(--c-mid);
  }

  .page-about .about-rail__facts span {
    font-family: var(--font-mono);
    font-size: 10px;
    letter-spacing: .16em;
    text-transform: uppercase;
    color: var(--c-silver);
  }

  .page-about .about-rail__facts b {
    font-family: var(--font-mono);
    font-size: 17px;
    color: var(--c-amber);
    letter-spacing: .02em;
  }

  .page-about .about-sec {
    padding-block: 60px;
  }

  .page-about .about-split {
    grid-template-columns: minmax(0, 1.45fr) minmax(0, 1fr);
    gap: 44px;
  }

  .page-about .about-kinds {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-steps {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

  .page-about .about-callout {
    grid-template-columns: 120px minmax(0, 1fr);
    align-items: baseline;
    column-gap: 18px;
    padding: 26px 26px 24px;
  }

  .page-about .about-callout__k:not(:first-child) {
    margin-top: 0;
  }

  .page-about .about-callout__note {
    grid-column: 1 / -1;
  }

  .page-about .about-cta__inner {
    grid-template-columns: minmax(0, 1fr) auto;
    padding-block: 52px;
    gap: 32px;
  }
}

@media (min-width: 1200px) {
  .page-about {
    --about-railw: 240px;
  }
}

/* ---------- 减少动态 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    transition-duration: .01ms !important;
    animation-duration: .01ms !important;
  }
}