.page-about {
  --about-gap: clamp(56px, 8vw, 112px);
  --about-stroke: 1px solid var(--steel);
  background: var(--void);
  color: var(--paper);
  padding-bottom: clamp(64px, 9vw, 120px);
  overflow-x: hidden;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  margin-top: 26px;
  border: 1px solid var(--steel);
  background:
    radial-gradient(120% 140% at 82% 12%, rgba(34, 224, 255, 0.14) 0%, rgba(34, 224, 255, 0) 58%),
    linear-gradient(135deg, var(--void) 0%, var(--purple-b) 54%, var(--navy) 100%);
  padding: 38px 20px 34px;
  overflow: hidden;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  right: 0;
  bottom: 0;
  width: 4px;
  height: 46%;
  background: linear-gradient(180deg, var(--cyan) 0%, var(--orange) 100%);
}

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

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

.page-about .about-hero__kicker {
  font-size: 12px;
  letter-spacing: 0.32em;
  color: var(--cyan);
  text-transform: uppercase;
  margin: 0 0 14px;
}

.page-about .about-hero__title {
  font-size: clamp(32px, 7.4vw, 68px);
  line-height: 1.1;
  font-weight: 900;
  letter-spacing: -0.02em;
  margin: 0 0 20px;
  color: var(--paper);
}

.page-about .about-hero__lead {
  max-width: 58ch;
  font-size: 16px;
  line-height: 1.9;
  color: var(--ash);
  margin: 0;
}

.page-about .about-hero__actions {
  margin-top: 28px;
}

.page-about .about-hero__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 20px 18px;
  margin: 34px 0 0;
  padding-top: 26px;
  border-top: var(--about-stroke);
}

.page-about .about-hero__stat dt {
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--ash);
  margin-bottom: 8px;
}

.page-about .about-hero__stat dd {
  margin: 0;
  color: var(--cyan);
  line-height: 1;
}

.page-about .about-hero__unit {
  font-size: 13px;
  font-weight: 500;
  color: var(--ash);
  margin-left: 4px;
  letter-spacing: 0.04em;
}

/* ---------- 章节公共头 ---------- */
.page-about .about-block {
  padding-top: var(--about-gap);
}

.page-about .about-head {
  display: grid;
  grid-template-columns: auto 1fr;
  column-gap: 16px;
  align-items: baseline;
  padding-bottom: 18px;
  border-bottom: var(--about-stroke);
  margin-bottom: 34px;
}

.page-about .about-head__no {
  color: var(--cyan);
  font-size: 15px;
}

.page-about .about-head__title {
  font-size: clamp(23px, 4vw, 36px);
  font-weight: 900;
  line-height: 1.25;
  letter-spacing: -0.01em;
  margin: 0;
  color: var(--paper);
}

.page-about .about-head__note {
  grid-column: 2 / -1;
  margin: 10px 0 0;
  font-size: 14px;
  color: var(--ash);
  line-height: 1.8;
}

/* ---------- 01 定位 ---------- */
.page-about .about-split {
  display: grid;
  grid-template-columns: 1fr;
  gap: 28px;
}

.page-about .about-split__text p {
  margin: 0 0 18px;
  font-size: 16px;
  line-height: 1.9;
  color: var(--paper);
}

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

.page-about .about-split__figure {
  margin: 0;
  border: var(--about-stroke);
  background: linear-gradient(150deg, var(--navy) 0%, var(--purple-a) 100%);
  padding: 10px;
}

.page-about .about-split__figure img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
  filter: saturate(0.9) contrast(1.05);
}

.page-about .about-split__caption {
  margin-top: 12px;
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--ash);
}

/* ---------- 02 四条主线 ---------- */
.page-about .about-lines {
  list-style: none;
  margin: 0;
  padding: 0;
  counter-reset: none;
}

.page-about .about-line {
  display: grid;
  grid-template-columns: 1fr;
  gap: 14px;
  padding: 30px 0;
  border-top: var(--about-stroke);
}

.page-about .about-line:first-child {
  border-top: none;
  padding-top: 0;
}

.page-about .about-line__no {
  color: var(--cyan-deep);
  letter-spacing: 0.04em;
  transition: color var(--t-mid) ease;
}

.page-about .about-line[data-reveal].is-visible .about-line__no,
.page-about .about-line:hover .about-line__no {
  color: var(--cyan);
}

.page-about .about-line__title {
  font-size: clamp(20px, 3.2vw, 26px);
  font-weight: 800;
  letter-spacing: -0.01em;
  margin: 0 0 10px;
  color: var(--paper);
}

.page-about .about-line__body p {
  margin: 0;
  font-size: 16px;
  line-height: 1.9;
  color: var(--ash);
}

.page-about .about-line__facts {
  list-style: none;
  margin: 4px 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 10px 14px;
}

.page-about .about-line__facts li {
  font-size: 13px;
  color: var(--paper);
  background: rgba(34, 224, 255, 0.08);
  border: 1px solid var(--cyan-deep);
  padding: 6px 12px;
  letter-spacing: 0.02em;
}

.page-about .about-line__facts .ng-num {
  color: var(--amber);
  margin-right: 4px;
}

/* ---------- 03 流程 ---------- */
.page-about .about-process {
  display: grid;
  grid-template-columns: 1fr;
  gap: 30px;
}

.page-about .about-process__figure {
  margin: 0;
  border: var(--about-stroke);
  background: linear-gradient(200deg, var(--purple-b) 0%, var(--void) 100%);
  padding: 12px;
}

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

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

.page-about .about-step {
  position: relative;
  padding: 0 0 24px 26px;
  border-left: 1px solid var(--steel);
}

.page-about .about-step:last-child {
  padding-bottom: 0;
}

.page-about .about-step::before {
  content: "";
  position: absolute;
  left: -4px;
  top: 6px;
  width: 7px;
  height: 7px;
  background: var(--mint);
  border-radius: 50%;
}

.page-about .about-step__idx {
  display: block;
  color: var(--amber);
  margin-bottom: 6px;
}

.page-about .about-step__title {
  font-size: 18px;
  font-weight: 800;
  margin: 0 0 8px;
  color: var(--paper);
}

.page-about .about-step p {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--ash);
}

.page-about .about-process__meta {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin-top: 38px;
  background: var(--steel);
  border: var(--about-stroke);
}

.page-about .about-metric {
  background: var(--navy);
  padding: 20px 16px;
}

.page-about .about-metric__num {
  display: block;
  color: var(--orange);
  line-height: 1;
  margin-bottom: 10px;
}

.page-about .about-metric__label {
  display: block;
  font-size: 13px;
  color: var(--ash);
  line-height: 1.6;
}

.page-about .about-process__foot {
  margin: 26px 0 0;
  font-size: 15px;
  line-height: 1.9;
  color: var(--ash);
  max-width: 68ch;
}

/* ---------- 04 版本演进 ---------- */
.page-about .about-version__figure {
  margin: 0 0 40px;
  border: var(--about-stroke);
  background: linear-gradient(120deg, var(--purple-a) 0%, var(--void) 72%);
  padding: 12px;
}

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

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

.page-about .about-timeline__node {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  padding: 0 0 46px 22px;
  border-left: 1px solid var(--steel);
  position: relative;
}

.page-about .about-timeline__node:last-child {
  padding-bottom: 0;
  border-left-color: transparent;
}

.page-about .about-timeline__node::before {
  content: "";
  position: absolute;
  left: -5px;
  top: 8px;
  width: 9px;
  height: 9px;
  background: var(--cyan);
  box-shadow: 0 0 0 4px rgba(34, 224, 255, 0.14);
}

.page-about .about-timeline__marker {
  display: flex;
  align-items: baseline;
  gap: 12px;
}

.page-about .about-timeline__year {
  font-size: clamp(34px, 6vw, 46px);
  color: var(--paper);
  letter-spacing: -0.02em;
  line-height: 1;
}

.page-about .about-timeline__ver {
  font-size: 12px;
  letter-spacing: 0.22em;
  color: var(--amber);
}

.page-about .about-card__title {
  font-size: clamp(18px, 2.6vw, 22px);
  font-weight: 800;
  line-height: 1.4;
  margin: 0 0 12px;
  color: var(--paper);
}

.page-about .about-timeline__card p {
  margin: 0;
  font-size: 15px;
  line-height: 1.9;
  color: var(--ash);
}

.page-about .about-timeline__more {
  margin-top: 16px;
  padding-top: 12px;
  border-top: 1px solid var(--steel);
}

.page-about .about-timeline__more summary {
  cursor: pointer;
  list-style: none;
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--cyan);
}

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

.page-about .about-timeline__more summary::after {
  content: " +";
  font-family: var(--font-mono);
  color: var(--orange);
}

.page-about .about-timeline__more[open] summary::after {
  content: " −";
}

.page-about .about-timeline__more p {
  margin-top: 12px;
  font-size: 14px;
  line-height: 1.85;
  color: var(--ash);
}

/* ---------- 05 合作与认可 ---------- */
.page-about .about-partner {
  display: grid;
  grid-template-columns: 1fr;
  gap: 22px;
}

.page-about .about-partner__lead {
  margin: 0;
  font-size: 16px;
  line-height: 1.9;
  color: var(--navy);
}

.page-about .about-partner__tags {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 20px 0 0;
}

.page-about .about-partner__cta {
  margin: 22px 0 0;
  padding-top: 16px;
  border-top: 1px solid rgba(11, 27, 51, 0.18);
}

.page-about .about-partner__cta .ng-meta__link {
  color: var(--cyan-deep);
  font-weight: 700;
  text-decoration: none;
  border-bottom: 1px solid currentColor;
}

.page-about .about-partner__side {
  display: grid;
  gap: 18px;
}

.page-about .about-honor {
  border: 1px solid var(--amber);
  background: linear-gradient(160deg, rgba(255, 176, 32, 0.12) 0%, rgba(255, 176, 32, 0) 70%);
  padding: 22px 20px;
}

.page-about .about-honor__tag {
  display: block;
  color: var(--amber);
  font-size: 18px;
  letter-spacing: 0.06em;
  margin-bottom: 12px;
}

.page-about .about-honor__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--paper);
}

.page-about .about-scale {
  margin: 0;
  border-top: var(--about-stroke);
}

.page-about .about-scale__row {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 14px;
  padding: 14px 0;
  border-bottom: var(--about-stroke);
}

.page-about .about-scale__row dt {
  font-size: 13px;
  color: var(--ash);
}

.page-about .about-scale__row dd {
  margin: 0;
  font-size: 14px;
  color: var(--paper);
}

.page-about .about-scale__row .ng-num {
  color: var(--cyan);
  font-size: 18px;
  margin-right: 2px;
}

/* ---------- 06 备案与时段 ---------- */
.page-about .about-record {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--steel);
  border: var(--about-stroke);
}

.page-about .about-record__cell {
  background: var(--navy);
  padding: 20px 18px;
}

.page-about .about-record__k {
  display: block;
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--ash);
  margin-bottom: 10px;
}

.page-about .about-record__v {
  display: block;
  font-size: 17px;
  color: var(--paper);
  line-height: 1.4;
}

.page-about .about-record__cell:nth-child(1) .about-record__v {
  color: var(--cyan);
}

.page-about .about-outro {
  margin-top: 40px;
  padding: 30px 20px;
  border: 1px solid var(--cyan-deep);
  background: linear-gradient(120deg, rgba(42, 20, 80, 0.9) 0%, rgba(5, 7, 14, 0.6) 100%);
}

.page-about .about-outro__text {
  margin: 0 0 22px;
  max-width: 60ch;
  font-size: 15px;
  line-height: 1.9;
  color: var(--ash);
}

.page-about .about-outro__links {
  gap: 12px;
}

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .about-hero {
    padding: 54px 40px 46px;
  }

  .page-about .about-hero__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 24px;
  }

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

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

  .page-about .about-outro {
    padding: 38px 34px;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__mark {
    display: block;
    position: absolute;
    right: 18px;
    top: 54px;
    writing-mode: vertical-rl;
    font-size: 12px;
    letter-spacing: 0.34em;
    color: var(--ash);
  }

  .page-about .about-hero__title {
    max-width: 20ch;
  }

  .page-about .about-split {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    gap: 48px;
    align-items: start;
  }

  .page-about .about-line {
    grid-template-columns: 88px minmax(0, 1fr) 250px;
    gap: 32px;
    align-items: start;
    padding: 38px 0;
  }

  .page-about .about-line:nth-child(even) {
    padding-left: 44px;
  }

  .page-about .about-line__facts {
    flex-direction: column;
    align-items: flex-start;
    margin-top: 2px;
  }

  .page-about .about-process {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1fr);
    gap: 52px;
    align-items: center;
  }

  .page-about .about-timeline__node {
    grid-template-columns: 200px minmax(0, 1fr);
    gap: 44px;
    padding-left: 0;
    padding-bottom: 56px;
  }

  .page-about .about-timeline__marker {
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
    padding-left: 24px;
    position: relative;
  }

  .page-about .about-timeline__node::before {
    left: -5px;
    top: 10px;
  }

  .page-about .about-partner {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, 0.85fr);
    gap: 34px;
    align-items: start;
  }

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

@media (min-width: 1100px) {
  .page-about .about-hero__inner::before {
    content: "";
    position: absolute;
    left: -46px;
    top: 6px;
    width: 1px;
    height: 120px;
    background: linear-gradient(180deg, var(--cyan) 0%, rgba(34, 224, 255, 0) 100%);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-line__no {
    transition: none;
  }
}