.page-about {
  background: var(--night);
  color: var(--text);
  overflow-x: hidden;
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  background:
    radial-gradient(1100px 520px at 78% -10%, rgba(56, 242, 224, 0.13), transparent 62%),
    radial-gradient(760px 420px at 4% 108%, rgba(255, 122, 47, 0.12), transparent 66%),
    var(--night);
  border-bottom: 1px solid var(--steel);
}

.page-about .about-hero__grid {
  display: grid;
  gap: 34px;
  margin-top: 30px;
}

@media (min-width: 980px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 52px;
    align-items: end;
  }
}

.page-about .about-hero__lead .m6-title {
  margin: 14px 0 0;
  max-width: 15em;
}

.page-about .about-hero__lead .m6-lede {
  margin-top: 20px;
  max-width: 34em;
}

.page-about .about-hero__facts {
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 10px 28px;
  margin: 30px 0 0;
  padding: 18px 0 0;
  border-top: 1px solid var(--steel);
}

.page-about .about-hero__facts li {
  font: 500 13px/1.5 var(--mono);
  letter-spacing: 0.03em;
  color: var(--slate);
}

.page-about .about-hero__facts b {
  color: var(--lime);
  font-weight: 700;
  margin-right: 4px;
}

.page-about .about-hero__figure {
  margin: 0;
  position: relative;
}

.page-about .about-hero__figure::after {
  content: "";
  position: absolute;
  left: -14px;
  bottom: 24px;
  width: 3px;
  height: 64px;
  background: var(--orange);
}

.page-about .about-hero__cap {
  margin-top: 12px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--slate);
  border-left: 1px solid var(--steel);
  padding-left: 12px;
}

/* ---------- 布局骨架：左侧索引 + 正文 ---------- */
.page-about .about-layout {
  display: grid;
  grid-template-columns: 1fr;
  padding-inline: 5%;
}

@media (min-width: 900px) {
  .page-about .about-layout {
    grid-template-columns: 172px minmax(0, 1fr);
    column-gap: 38px;
  }
}

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

@media (min-width: 900px) {
  .page-about .about-rail {
    display: block;
    position: sticky;
    top: calc(var(--bar-h) + 36px);
    align-self: start;
    padding-top: 56px;
  }
}

.page-about .about-rail__title {
  margin: 0 0 16px;
  font: 700 11px/1 var(--sans);
  letter-spacing: 0.16em;
  color: var(--slate);
}

.page-about .about-rail__list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-left: 1px solid var(--steel);
}

.page-about .about-rail__link {
  display: flex;
  gap: 8px;
  align-items: baseline;
  padding: 9px 0 9px 14px;
  margin-left: -1px;
  border-left: 2px solid transparent;
  font-size: 13px;
  line-height: 1.45;
  color: var(--slate);
  text-decoration: none;
  transition: color 240ms var(--ease), border-color 240ms var(--ease);
}

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

.page-about .about-rail__no {
  font: 500 11px/1 var(--mono);
  color: var(--steel);
  filter: brightness(2.4);
}

/* ---------- 通用区块 ---------- */
.page-about .about-main > .m6-section {
  padding-left: 0;
  padding-right: 0;
  border-top: 1px solid var(--steel);
}

.page-about .about-main > .m6-section:first-child {
  border-top: 0;
}

.page-about .about-main .m6-section--paper {
  color: var(--ink);
  border-top-color: rgba(36, 28, 23, 0.16);
}

.page-about .about-main .m6-section--paper .m6-h2,
.page-about .about-main .m6-section--paper .m6-h3 {
  color: var(--ink);
}

.page-about .about-main .m6-section--paper .m6-eyebrow {
  color: rgba(36, 28, 23, 0.52);
}

.page-about .about-sec .m6-h2 {
  margin: 12px 0 0;
  max-width: 20em;
}

.page-about .about-lede {
  margin: 16px 0 0;
  max-width: 40em;
  font-size: 16px;
  line-height: 1.78;
}

.page-about .about-main .m6-section--paper .about-lede {
  color: rgba(36, 28, 23, 0.78);
}

/* ---------- 三件事 ---------- */
.page-about .about-trio {
  display: grid;
  gap: 20px;
  margin-top: 34px;
}

@media (min-width: 820px) {
  .page-about .about-trio {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 24px;
  }
}

.page-about .about-trio__item {
  position: relative;
  padding: 26px 20px 22px;
  background: rgba(36, 28, 23, 0.05);
  clip-path: var(--cut);
}

.page-about .about-trio__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 3px;
  height: 100%;
  background: var(--orange);
  opacity: 0.85;
}

.page-about .about-trio__no {
  display: block;
  font: 700 12px/1 var(--mono);
  letter-spacing: 0.12em;
  color: rgba(36, 28, 23, 0.45);
}

.page-about .about-trio__item .m6-h3 {
  margin: 12px 0 10px;
  font-size: 18px;
  line-height: 1.4;
}

.page-about .about-trio__item p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: rgba(36, 28, 23, 0.74);
}

/* ---------- 数据来处 ---------- */
.page-about .about-split {
  display: grid;
  gap: 30px;
}

@media (min-width: 940px) {
  .page-about .about-split {
    grid-template-columns: minmax(0, 6fr) minmax(0, 6fr);
    gap: 48px;
    align-items: start;
  }
}

.page-about .about-split__text p {
  margin: 16px 0 0;
  max-width: 38em;
  font-size: 15.5px;
  line-height: 1.8;
  color: var(--text);
}

.page-about .about-check {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  border-top: 1px solid var(--steel);
}

.page-about .about-check li {
  display: grid;
  grid-template-columns: 1fr;
  gap: 4px;
  padding: 14px 0;
  border-bottom: 1px solid var(--steel);
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--slate);
}

@media (min-width: 560px) {
  .page-about .about-check li {
    grid-template-columns: 148px minmax(0, 1fr);
    gap: 18px;
    align-items: baseline;
  }
}

.page-about .about-check b {
  font: 700 13px/1.5 var(--sans);
  letter-spacing: 0.04em;
  color: var(--cyan);
}

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

.page-about .about-split__media::before {
  content: "";
  display: block;
  height: 1px;
  margin-bottom: 20px;
  background: linear-gradient(90deg, var(--cyan), rgba(56, 242, 224, 0));
}

.page-about .about-split__cap {
  margin-top: 12px;
  font-size: 13px;
  line-height: 1.72;
  color: var(--slate);
}

/* ---------- 团队 ---------- */
.page-about .about-roles {
  display: grid;
  gap: 18px;
  margin-top: 26px;
}

@media (min-width: 760px) {
  .page-about .about-roles {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 22px;
  }
}

.page-about .about-role {
  position: relative;
  padding: 24px 20px 22px;
  background: rgba(36, 28, 23, 0.045);
  clip-path: var(--cut);
}

.page-about .about-role::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 3px;
  height: 100%;
  background: var(--ink);
}

.page-about .about-role--data::before {
  background: var(--orange);
}

.page-about .about-role--content::before {
  background: var(--ink);
}

.page-about .about-role--product::before {
  background: var(--magenta);
}

.page-about .about-role__name {
  margin: 0;
  font: 700 14px/1.4 var(--sans);
  letter-spacing: 0.05em;
  color: var(--ink);
}

.page-about .about-role__num {
  margin: 12px 0 0;
  display: flex;
  align-items: baseline;
  gap: 4px;
  color: var(--ink);
}

.page-about .about-role__num .m6-num {
  font-size: 38px;
  font-weight: 700;
}

.page-about .about-role__unit {
  font: 500 13px/1 var(--sans);
  color: rgba(36, 28, 23, 0.6);
}

.page-about .about-role__track {
  height: 8px;
  margin: 16px 0 14px;
  background: rgba(36, 28, 23, 0.12);
}

.page-about .about-role__track span {
  display: block;
  height: 100%;
  width: var(--w, 0%);
  background: var(--ink);
}

.page-about .about-role--data .about-role__track span {
  --w: 50%;
  background: var(--orange);
}

.page-about .about-role--content .about-role__track span {
  --w: 29%;
  background: var(--ink);
}

.page-about .about-role--product .about-role__track span {
  --w: 21%;
  background: var(--magenta);
}

.page-about .about-role__desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: rgba(36, 28, 23, 0.74);
}

/* ---------- 版本时间轴 ---------- */
.page-about .about-timeline {
  position: relative;
  margin-top: 34px;
  padding-left: 30px;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: linear-gradient(180deg, var(--cyan) 0%, rgba(56, 242, 224, 0.12) 100%);
}

.page-about .about-node {
  position: relative;
  padding-bottom: 32px;
}

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

.page-about .about-node::before {
  content: "";
  position: absolute;
  left: -30px;
  top: 5px;
  width: 12px;
  height: 12px;
  background: var(--lime);
  clip-path: var(--cut-xs);
}

.page-about .about-node__stage {
  margin: 0;
  font: 700 12px/1 var(--mono);
  letter-spacing: 0.14em;
  color: var(--cyan);
}

.page-about .about-node .m6-h3 {
  margin: 10px 0 8px;
  font-size: 18px;
  line-height: 1.42;
  color: var(--text);
}

.page-about .about-node__text {
  margin: 0 0 12px;
  max-width: 44em;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--slate);
}

/* ---------- 合作与覆盖 ---------- */
.page-about .about-partners {
  display: grid;
  gap: 22px;
  margin-top: 32px;
}

@media (min-width: 700px) {
  .page-about .about-partners {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 26px 32px;
  }
}

@media (min-width: 1080px) {
  .page-about .about-partners {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

.page-about .about-figure {
  padding-top: 16px;
  border-top: 2px solid var(--ink);
}

.page-about .about-figure__n {
  margin: 0;
  font-size: clamp(34px, 4.4vw, 48px);
  font-weight: 700;
  line-height: 1;
  color: var(--ink);
  letter-spacing: -0.02em;
}

.page-about .about-figure__unit {
  font-size: 0.46em;
  margin-left: 3px;
  color: rgba(36, 28, 23, 0.62);
}

.page-about .about-figure__k {
  margin: 12px 0 0;
  font: 700 14px/1.4 var(--sans);
  letter-spacing: 0.04em;
  color: rgba(36, 28, 23, 0.88);
}

.page-about .about-figure__d {
  margin: 8px 0 0;
  font-size: 13.5px;
  line-height: 1.75;
  color: rgba(36, 28, 23, 0.68);
}

/* ---------- 下一步 ---------- */
.page-about .about-next {
  list-style: none;
  margin: 30px 0 0;
  padding: 0;
  border-top: 1px solid var(--steel);
}

.page-about .about-next li {
  border-bottom: 1px solid var(--steel);
}

.page-about .about-next__link {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: center;
  gap: 4px 18px;
  padding: 18px 4px;
  text-decoration: none;
  color: var(--text);
  transition: background-color 240ms var(--ease), padding-left 240ms var(--ease);
}

.page-about .about-next__link:hover,
.page-about .about-next__link:focus-visible {
  background: rgba(56, 242, 224, 0.07);
  padding-left: 14px;
}

.page-about .about-next__t {
  font: 700 16px/1.4 var(--sans);
  letter-spacing: 0.02em;
  color: var(--cyan);
}

.page-about .about-next__d {
  grid-column: 1 / 2;
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--slate);
}

.page-about .about-next__arrow {
  grid-row: 1 / 3;
  grid-column: 2 / 3;
  font: 700 18px/1 var(--mono);
  color: var(--orange);
  transition: transform 240ms var(--ease);
}

.page-about .about-next__link:hover .about-next__arrow,
.page-about .about-next__link:focus-visible .about-next__arrow {
  transform: translateX(5px);
}

/* ---------- 窄屏修正 ---------- */
@media (max-width: 899px) {
  .page-about .about-hero__figure::after {
    display: none;
  }

  .page-about .about-timeline {
    padding-left: 24px;
  }

  .page-about .about-node::before {
    left: -24px;
  }
}

@media (max-width: 560px) {
  .page-about .about-hero__facts {
    gap: 8px 18px;
  }

  .page-about .about-hero__facts li {
    font-size: 12px;
  }

  .page-about .about-next__link {
    grid-template-columns: 1fr;
  }

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