.page-about {
  --about-radius: 4px;
  --about-line-soft: rgba(36, 50, 92, 0.75);
  position: relative;
  background:
    radial-gradient(880px 480px at 102% 0%, rgba(138, 107, 255, 0.16), transparent 62%),
    radial-gradient(720px 420px at -6% 10%, rgba(53, 240, 216, 0.09), transparent 64%);
}

.page-about .section {
  padding: 54px 0;
}

.page-about .about-head {
  max-width: 660px;
  margin-bottom: 32px;
}

.page-about .crumbs {
  margin-bottom: 26px;
}

/* ------- 首屏 ------- */
.page-about .about-hero {
  position: relative;
  padding: 26px 0 0;
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -70px;
  right: -90px;
  width: 340px;
  height: 340px;
  background: linear-gradient(150deg, rgba(138, 107, 255, 0.32), transparent 72%);
  clip-path: polygon(22% 0, 100% 0, 100% 78%, 0 100%);
  pointer-events: none;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: 18px;
  width: 44%;
  height: 1px;
  background: linear-gradient(90deg, var(--cyan), rgba(53, 240, 216, 0));
  opacity: 0.55;
  pointer-events: none;
}

.page-about .about-hero__inner {
  position: relative;
  display: grid;
  gap: 28px;
  align-items: start;
}

.page-about .about-hero__copy .h1 {
  margin: 10px 0 16px;
}

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

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 28px 0 0;
  padding: 0;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--about-radius);
  overflow: hidden;
}

.page-about .about-stats__item {
  background: rgba(7, 11, 26, 0.88);
  padding: 14px 16px;
}

.page-about .about-stats__key {
  font-family: var(--mono);
  font-size: 11px;
  letter-spacing: 1px;
  color: var(--ink-2);
  margin: 0;
}

.page-about .about-stats__val {
  margin: 6px 0 0;
  font-family: var(--mono);
  font-size: 24px;
  font-weight: 600;
  letter-spacing: -0.5px;
  line-height: 1.1;
  color: var(--cyan);
}

/* ------- 媒体容器 ------- */
.page-about .media__frame {
  overflow: hidden;
  border: 1px solid var(--line);
  border-radius: var(--about-radius);
  background: rgba(14, 21, 48, 0.6);
}

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

.page-about .media__cap {
  margin-top: 10px;
  font-size: 12px;
  line-height: 1.6;
  color: var(--ink-2);
}

/* ------- 时间轴 ------- */
.page-about .about-tree {
  display: grid;
  gap: 20px;
}

.page-about .about-index__label {
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 1px;
  text-transform: uppercase;
  color: var(--ink-2);
  margin: 0 0 10px;
}

.page-about .about-index__list {
  display: flex;
  gap: 10px;
  list-style: none;
  margin: 0;
  padding: 0;
  overflow-x: auto;
  scrollbar-width: thin;
}

.page-about .about-index__link {
  display: inline-block;
  font-family: var(--mono);
  font-size: 14px;
  letter-spacing: 0.5px;
  color: var(--ink-2);
  text-decoration: none;
  padding: 6px 10px;
  border-left: 2px solid var(--line);
  white-space: nowrap;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}

.page-about .about-index__link:hover,
.page-about .about-index__link:focus-visible {
  color: var(--cyan);
  border-left-color: var(--cyan);
}

.page-about .about-line {
  display: grid;
  gap: 22px;
}

.page-about .about-phase {
  position: relative;
  padding: 22px 20px 20px;
  border: 1px solid var(--line);
  border-left: 2px solid var(--cyan);
  border-radius: var(--about-radius);
  background: linear-gradient(180deg, rgba(22, 32, 61, 0.88), rgba(14, 21, 48, 0.7));
  transition: border-color 0.18s var(--ease);
}

.page-about .about-phase:nth-child(2) {
  border-left-color: var(--violet);
}

.page-about .about-phase:nth-child(3) {
  border-left-color: var(--orange);
}

.page-about .about-phase:hover {
  border-color: rgba(53, 240, 216, 0.45);
}

.page-about .about-phase__year {
  display: inline-block;
  font-family: var(--mono);
  font-size: clamp(26px, 6.4vw, 38px);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.5px;
  color: var(--deep);
  background: linear-gradient(100deg, var(--cyan), #86f5e6);
  padding: 6px 16px 8px;
  border-radius: 2px;
  transform: skewX(-8deg);
}

.page-about .about-phase .tag {
  margin: 14px 0 0;
}

.page-about .about-phase__title {
  margin: 12px 0 10px;
  font-family: var(--narrow);
  font-size: 21px;
  font-weight: 700;
  line-height: 1.35;
  letter-spacing: -0.3px;
  color: var(--ink);
}

.page-about .about-phase__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-2);
}

.page-about .about-phase .accordion {
  margin-top: 16px;
  border-top: 1px solid var(--line);
  padding-top: 4px;
}

/* ------- 版本轨道 ------- */
.page-about .about-track__head {
  display: grid;
  gap: 24px;
  align-items: center;
  margin-bottom: 26px;
}

.page-about .about-track__lede {
  margin: 12px 0 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--ink-2);
}

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

.page-about .about-track__railwrap {
  position: relative;
  margin: 0 -20px;
  padding: 4px 20px 0;
}

.page-about .about-track__railwrap::after {
  content: "";
  position: absolute;
  top: 4px;
  right: 0;
  bottom: 18px;
  width: 46px;
  background: linear-gradient(270deg, var(--deep), rgba(7, 11, 26, 0));
  pointer-events: none;
}

.page-about .about-track {
  display: flex;
  gap: 14px;
  list-style: none;
  margin: 0;
  padding: 0 0 16px;
  overflow-x: auto;
  scroll-snap-type: x proximity;
  scrollbar-width: thin;
  scrollbar-color: var(--line) transparent;
}

.page-about .about-track__item {
  flex: 0 0 208px;
  scroll-snap-align: start;
  display: flex;
  flex-direction: column;
  gap: 10px;
  padding: 16px 14px;
  border: 1px solid var(--line);
  border-radius: var(--about-radius);
  background: rgba(22, 32, 61, 0.55);
  transition: border-color 0.18s var(--ease), transform 0.18s var(--ease);
}

.page-about .about-track__item:hover {
  border-color: var(--cyan);
  transform: translateY(-3px);
}

.page-about .about-track__no {
  font-family: var(--mono);
  font-size: 18px;
  letter-spacing: 0.5px;
  color: var(--violet);
}

.page-about .about-track__label {
  font-size: 14px;
  line-height: 1.6;
  color: var(--ink);
}

.page-about .about-track__hint {
  margin: 4px 0 0;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 0.5px;
  color: var(--ink-2);
}

/* ------- 覆盖 ------- */
.page-about .about-nums {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  gap: 14px;
  grid-template-columns: repeat(auto-fit, minmax(132px, 1fr));
}

.page-about .about-nums li {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding-left: 12px;
  border-left: 2px solid var(--violet);
}

.page-about .about-nums__v {
  font-family: var(--mono);
  font-size: 26px;
  font-weight: 600;
  line-height: 1.1;
  color: var(--cyan);
}

.page-about .about-nums__k {
  font-size: 13px;
  color: var(--ink-2);
}

.page-about .about-region {
  padding: 20px 18px;
  border: 1px solid var(--line);
  border-radius: var(--about-radius);
  background: rgba(14, 21, 48, 0.72);
}

.page-about .about-region__label {
  margin: 0 0 16px;
  font-family: var(--mono);
  font-size: 12px;
  letter-spacing: 1px;
  text-transform: uppercase;
  color: var(--ink-2);
}

.page-about .about-region__row {
  display: grid;
  grid-template-columns: 58px 1fr 44px;
  align-items: center;
  gap: 10px;
  margin-bottom: 12px;
}

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

.page-about .about-region__name {
  font-size: 13px;
  color: var(--ink-2);
}

.page-about .about-region__bar {
  display: block;
  height: 8px;
  border-radius: 2px;
  background: var(--about-line-soft);
  overflow: hidden;
}

.page-about .about-region__fill {
  display: block;
  height: 100%;
  border-radius: 2px;
  background: linear-gradient(90deg, var(--cyan), var(--violet));
}

.page-about .about-region__pct {
  font-family: var(--mono);
  font-size: 13px;
  text-align: right;
  color: var(--ink);
}

/* ------- 团队 ------- */
.page-about .about-team__inner {
  display: grid;
  gap: 28px;
  align-items: center;
}

.page-about .about-team__list {
  list-style: none;
  margin: 20px 0 24px;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .about-team__list li {
  position: relative;
  padding-left: 18px;
  font-size: 15px;
  line-height: 1.75;
  color: var(--ink-2);
}

.page-about .about-team__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.66em;
  width: 8px;
  height: 8px;
  border-radius: 1px;
  background: var(--cyan);
}

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

/* ------- 资质 ------- */
.page-about .about-cert__list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.page-about .about-cert__item {
  display: grid;
  grid-template-columns: 48px 1fr;
  gap: 16px;
  padding: 18px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .about-cert__no {
  font-family: var(--mono);
  font-size: 20px;
  line-height: 1.25;
  color: var(--orange);
}

.page-about .about-cert__title {
  margin: 0 0 6px;
  font-family: var(--narrow);
  font-size: 18px;
  font-weight: 700;
  line-height: 1.4;
  letter-spacing: -0.2px;
  color: var(--ink);
}

.page-about .about-cert__text {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--ink-2);
}

/* ------- 协作 ------- */
.page-about .about-partner__grid {
  gap: 16px;
}

.page-about .about-partner__grid .card {
  border-left: 2px solid var(--violet);
}

/* ------- 结尾入口 ------- */
.page-about .about-next__panel {
  padding: 28px 22px;
  border: 1px solid var(--line);
  border-radius: var(--about-radius);
  background:
    linear-gradient(118deg, rgba(138, 107, 255, 0.2), transparent 58%),
    rgba(14, 21, 48, 0.82);
}

.page-about .about-next__links {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 20px;
}

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

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

  .page-about .about-track__item {
    flex: 0 0 232px;
  }
}

@media (min-width: 900px) {
  .page-about .section {
    padding: 78px 0;
  }

  .page-about .about-hero {
    padding-top: 34px;
  }

  .page-about .about-hero__inner {
    grid-template-columns: 1.05fr 0.85fr;
    gap: 48px;
  }

  .page-about .about-track__head {
    grid-template-columns: 1fr 0.68fr;
    gap: 44px;
  }

  .page-about .about-team__inner {
    grid-template-columns: 1fr 0.78fr;
    gap: 48px;
  }

  .page-about .about-next__panel {
    padding: 36px 34px;
  }
}

@media (min-width: 960px) {
  .page-about .about-tree {
    grid-template-columns: 116px 1fr;
    gap: 42px;
  }

  .page-about .about-index {
    position: sticky;
    top: calc(var(--topbar-h) + 24px);
    align-self: start;
  }

  .page-about .about-index__list {
    flex-direction: column;
    gap: 6px;
    overflow: visible;
  }

  .page-about .about-track__railwrap {
    margin: 0;
    padding: 4px 0 0;
  }

  .page-about .about-track__railwrap::after {
    right: -1px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-track__item,
  .page-about .about-phase,
  .page-about .about-index__link {
    transition: none;
  }
}