.page-about {
  --about-rail: 208px;
  --about-gap: clamp(28px, 4vw, 60px);
  --about-line: rgba(199, 206, 218, .16);
  background: var(--ink-night);
  color: var(--text-hi);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.75;
}

.page-about * {
  box-sizing: border-box;
}

/* ---------- 面包屑 ---------- */
.page-about .crumbs {
  max-width: var(--shell-w);
  margin: 0 auto;
  padding: clamp(20px, 3vw, 34px) var(--shell-pad) 0;
  font-size: 13px;
  color: var(--mist);
}

.page-about .crumbs ol {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0;
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .crumbs li + li::before {
  content: "/";
  margin: 0 10px;
  color: rgba(199, 206, 218, .38);
}

.page-about .crumbs a {
  color: var(--mist);
  text-decoration: none;
  transition: color .22s var(--ease);
}

.page-about .crumbs a:hover,
.page-about .crumbs a:focus-visible {
  color: var(--cyan);
}

.page-about .crumbs li[aria-current="page"] {
  color: var(--text-hi);
}

/* ---------- 首屏 ---------- */
.about-hero {
  position: relative;
  isolation: isolate;
  padding: clamp(30px, 5vw, 66px) 0 clamp(40px, 6vw, 84px);
}

.about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  z-index: -1;
  pointer-events: none;
  background:
    radial-gradient(120% 90% at 88% 4%, rgba(34, 224, 214, .15), transparent 58%),
    linear-gradient(180deg, rgba(14, 22, 48, .92), rgba(7, 11, 26, 0) 78%);
  transform: skewY(-6deg) scale(1.06);
  transform-origin: top left;
}

.about-hero__inner {
  display: grid;
  gap: clamp(30px, 4vw, 56px);
  align-items: center;
}

.about-hero h1 {
  font-family: var(--font-h);
  font-weight: 700;
  font-size: clamp(30px, 4.6vw, 54px);
  line-height: 1.13;
  letter-spacing: -.02em;
  margin: 14px 0 0;
  color: #fff;
  max-width: 20ch;
}

.about-hero .eyebrow {
  margin: 0;
}

.about-hero__lead {
  margin: 20px 0 0;
  max-width: 56ch;
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.8;
  color: var(--mist);
}

.about-hero__metrics {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: clamp(12px, 2vw, 28px);
  margin: 32px 0 0;
  padding-top: 20px;
  border-top: 1px solid rgba(199, 206, 218, .28);
}

.about-metric__num {
  display: block;
  font-family: var(--font-num);
  font-weight: 800;
  font-size: clamp(30px, 5vw, 48px);
  line-height: 1;
  letter-spacing: -.02em;
}

.about-metric:nth-child(1) .about-metric__num { color: var(--cyan); }
.about-metric:nth-child(2) .about-metric__num { color: var(--hot); }
.about-metric:nth-child(3) .about-metric__num { color: var(--paper); }

.about-metric__label {
  display: block;
  margin-top: 9px;
  font-size: 12.5px;
  line-height: 1.5;
  color: var(--mist);
}

.about-hero__acts {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 32px;
}

.about-hero__media {
  margin: 0;
  position: relative;
  padding: 10px;
  border: 1px solid rgba(199, 206, 218, .26);
  background: linear-gradient(140deg, rgba(34, 224, 214, .09), rgba(255, 90, 31, .05) 70%);
}

.about-hero__media::after {
  content: "";
  position: absolute;
  right: 10px;
  bottom: 10px;
  width: 46px;
  height: 3px;
  background: var(--hot);
}

.about-hero__media img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  filter: saturate(.9) contrast(1.05);
}

/* ---------- 骨架：索引栏 + 正文 ---------- */
.about-layout {
  padding-bottom: clamp(52px, 8vw, 104px);
}

.about-rail {
  margin-bottom: 30px;
}

.about-rail .index-rail__head {
  margin: 0 0 12px;
  font-family: var(--font-serif);
  font-size: 12px;
  letter-spacing: .18em;
  color: var(--mist);
}

.about-rail__nav {
  display: flex;
  gap: 8px;
  overflow-x: auto;
  padding-bottom: 8px;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: thin;
}

.about-rail .index-rail__link {
  flex: 0 0 auto;
  padding: 10px 15px;
  border: 1px solid var(--about-line);
  color: var(--mist);
  font-size: 13.5px;
  line-height: 1.2;
  white-space: nowrap;
  text-decoration: none;
  transition: color .22s var(--ease), border-color .22s var(--ease),
              background-color .22s var(--ease);
}

.about-rail .index-rail__link:hover,
.about-rail .index-rail__link:focus-visible {
  color: var(--text-hi);
  border-color: rgba(199, 206, 218, .34);
}

.about-rail .index-rail__link[aria-current="true"] {
  color: var(--ink-night);
  background: var(--cyan);
  border-color: var(--cyan);
  font-weight: 600;
}

/* ---------- 通用章节 ---------- */
.about-sec {
  position: relative;
  padding: clamp(34px, 5.5vw, 62px) 0;
  border-top: 1px solid var(--about-line);
}

.about-sec:first-child {
  border-top: 0;
  padding-top: 0;
}

.about-sec__head {
  margin-bottom: clamp(18px, 2.4vw, 26px);
}

.about-sec .eyebrow {
  margin: 0;
  color: var(--cyan);
}

.about-sec h2 {
  font-family: var(--font-h);
  font-weight: 700;
  font-size: clamp(21px, 2.7vw, 32px);
  line-height: 1.28;
  letter-spacing: -.012em;
  margin: 10px 0 0;
  color: var(--text-hi);
}

.about-sec p {
  margin: 0 0 16px;
  max-width: 68ch;
  color: var(--mist);
}

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

.about-sec a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(34, 224, 214, .38);
  transition: border-color .22s var(--ease), color .22s var(--ease);
}

.about-sec a:hover,
.about-sec a:focus-visible {
  color: #fff;
  border-bottom-color: #fff;
}

.about-sec__foot {
  margin-top: clamp(18px, 2.4vw, 26px) !important;
  padding-top: 18px;
  border-top: 1px solid var(--about-line);
  font-size: 14.5px;
}

/* ---------- 定位要点 ---------- */
.about-points {
  list-style: none;
  display: grid;
  gap: 1px;
  margin: clamp(22px, 3vw, 30px) 0 0;
  padding: 0;
  background: var(--about-line);
}

.about-points li {
  background: var(--track-blue);
  border-top: 2px solid var(--cyan);
  padding: 18px 18px 20px;
  font-size: 14.5px;
  line-height: 1.7;
  color: var(--text-hi);
}

/* ---------- 内容覆盖（暖纸断面） ---------- */
.about-sec--paper {
  background: var(--paper);
  color: var(--ink-black);
  border-top: 0;
  padding: clamp(28px, 4vw, 48px) clamp(20px, 3vw, 42px);
  box-shadow: 0 30px 70px -34px rgba(0, 0, 0, .8);
}

.about-sec--paper::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 4px;
  background: linear-gradient(90deg, var(--hot) 0%, rgba(255, 90, 31, .12) 62%, transparent 100%);
}

.about-sec--paper .eyebrow {
  color: var(--deep-teal);
}

.about-sec--paper h2 {
  color: var(--ink-black);
}

.about-sec--paper p {
  color: var(--paper-gray);
}

.about-sec--paper a {
  color: var(--deep-teal);
  border-bottom-color: rgba(11, 122, 114, .4);
}

.about-sec--paper a:hover,
.about-sec--paper a:focus-visible {
  color: var(--ink-black);
  border-bottom-color: var(--ink-black);
}

.about-sec--paper .about-sec__foot {
  border-top-color: rgba(18, 20, 28, .16);
}

.about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: clamp(16px, 2.4vw, 26px);
  margin: clamp(20px, 3vw, 30px) 0 0;
}

.about-stat {
  border-top: 2px solid var(--ink-black);
  padding-top: 12px;
}

.about-stat__num {
  margin: 0;
  font-family: var(--font-num);
  font-weight: 800;
  font-size: clamp(32px, 4.6vw, 50px);
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--ink-black);
}

.about-stat__num em {
  font-style: normal;
  font-family: var(--font-h);
  font-size: 14px;
  font-weight: 600;
  margin-left: 5px;
  letter-spacing: 0;
  color: var(--deep-teal);
}

.about-stat__label {
  margin: 9px 0 0;
  font-size: 13px;
  line-height: 1.6;
  color: var(--paper-gray);
}

/* ---------- 团队 ---------- */
.about-team {
  display: grid;
  gap: 1px;
  margin: clamp(20px, 3vw, 30px) 0 0;
  background: var(--about-line);
}

.about-team__item {
  position: relative;
  background: var(--stand-blue);
  padding: clamp(18px, 2.4vw, 28px);
}

.about-team__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 2px;
  background: linear-gradient(180deg, var(--cyan), rgba(34, 224, 214, 0));
}

.about-team__no {
  display: block;
  font-family: var(--font-num);
  font-size: 12px;
  font-weight: 700;
  letter-spacing: .2em;
  color: var(--cyan);
}

.about-team__name {
  font-family: var(--font-h);
  font-size: 18px;
  font-weight: 700;
  margin: 9px 0 0;
  color: var(--text-hi);
}

.about-team__desc {
  margin: 9px 0 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--mist);
  max-width: 42ch;
}

/* ---------- 生产流程 ---------- */
.about-flow__media {
  margin: clamp(20px, 3vw, 30px) 0 0;
  border: 1px solid var(--about-line);
  padding: 8px;
}

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

.about-flow__media .frame__caption {
  display: block;
  margin: 10px 2px 2px;
  font-size: 12px;
  letter-spacing: .02em;
  color: var(--mist);
}

.about-flow__list {
  list-style: none;
  display: grid;
  gap: clamp(16px, 2.2vw, 24px);
  margin: clamp(24px, 3.4vw, 36px) 0 0;
  padding: 0;
}

.about-flow__step {
  border-top: 2px solid rgba(34, 224, 214, .38);
  padding-top: 14px;
}

.about-flow__idx {
  display: block;
  font-family: var(--font-num);
  font-size: 26px;
  font-weight: 800;
  line-height: 1;
  letter-spacing: -.01em;
  color: var(--cyan);
}

.about-flow__title {
  font-family: var(--font-h);
  font-size: 16.5px;
  font-weight: 700;
  margin: 10px 0 0;
  color: var(--text-hi);
}

.about-flow__desc {
  margin: 8px 0 0;
  font-size: 13.5px;
  line-height: 1.68;
  color: var(--mist);
}

.about-flow__toggle {
  margin-top: 10px;
  padding: 8px 0;
  min-height: 36px;
  background: none;
  border: 0;
  border-bottom: 1px dashed rgba(34, 224, 214, .5);
  color: var(--cyan);
  font-family: var(--font-body);
  font-size: 12.5px;
  line-height: 1.2;
  cursor: pointer;
  transition: color .22s var(--ease), border-color .22s var(--ease);
}

.about-flow__toggle:hover,
.about-flow__toggle:focus-visible {
  color: #fff;
  border-bottom-color: #fff;
}

.about-flow__panel {
  margin-top: 12px;
  padding-left: 12px;
  border-left: 2px solid rgba(199, 206, 218, .3);
}

.about-flow__panel p {
  margin: 0;
  font-size: 13px;
  line-height: 1.68;
  color: var(--mist);
}

/* ---------- 版本时间轴 ---------- */
.about-tl-wrap {
  display: grid;
  gap: clamp(24px, 4vw, 44px);
  margin-top: clamp(20px, 3vw, 30px);
}

.about-tl__list {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0 0 0 26px;
  display: grid;
  gap: clamp(22px, 3vw, 32px);
}

.about-tl__list::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 8px;
  bottom: 8px;
  width: 1px;
  background: linear-gradient(180deg, var(--cyan), rgba(34, 224, 214, .08));
}

.about-tl__node {
  position: relative;
}

.about-tl__node::before {
  content: "";
  position: absolute;
  left: -26px;
  top: 7px;
  width: 11px;
  height: 11px;
  border-radius: 50%;
  background: var(--ink-night);
  border: 2px solid var(--cyan);
}

.about-tl__node:last-child::before {
  background: var(--hot);
  border-color: var(--hot);
  box-shadow: 0 0 0 4px rgba(255, 90, 31, .18);
}

.about-tl__ver {
  margin: 0;
  font-family: var(--font-num);
  font-weight: 800;
  font-size: clamp(28px, 3.6vw, 42px);
  line-height: 1;
  letter-spacing: -.02em;
  color: var(--text-hi);
}

.about-tl__node:last-child .about-tl__ver {
  color: var(--hot);
}

.about-tl__era {
  margin: 8px 0 0;
  font-size: 13px;
  letter-spacing: .06em;
  color: var(--cyan);
}

.about-tl__node:last-child .about-tl__era {
  color: rgba(255, 90, 31, .92);
}

.about-tl__note {
  margin: 8px 0 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--mist);
  max-width: 46ch;
}

.about-tl__btn {
  margin-top: 10px;
  padding: 8px 0;
  min-height: 36px;
  background: none;
  border: 0;
  border-bottom: 1px dashed rgba(199, 206, 218, .42);
  color: var(--mist);
  font-family: var(--font-body);
  font-size: 12.5px;
  cursor: pointer;
  transition: color .22s var(--ease), border-color .22s var(--ease);
}

.about-tl__btn:hover,
.about-tl__btn:focus-visible {
  color: var(--text-hi);
  border-bottom-color: var(--text-hi);
}

.about-tl__panel {
  margin-top: 12px;
  padding-left: 12px;
  border-left: 2px solid rgba(199, 206, 218, .28);
}

.about-tl__panel p {
  margin: 0;
  font-size: 13px;
  line-height: 1.68;
  color: var(--mist);
}

.about-tl__figure {
  margin: 0;
  border: 1px solid var(--about-line);
  padding: 8px;
}

.about-tl__figure img {
  display: block;
  width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
}

.about-tl__figure .frame__caption {
  display: block;
  margin: 10px 2px 2px;
  font-size: 12px;
  letter-spacing: .02em;
  color: var(--mist);
}

/* ---------- 地域与视觉 ---------- */
.about-region {
  position: relative;
  margin-top: clamp(20px, 3vw, 30px);
  padding: clamp(24px, 3.4vw, 42px);
  border: 1px solid var(--about-line);
  background:
    repeating-linear-gradient(115deg, rgba(34, 224, 214, .085) 0 1px, transparent 1px 28px),
    repeating-linear-gradient(65deg, rgba(199, 206, 218, .05) 0 1px, transparent 1px 36px),
    linear-gradient(160deg, rgba(22, 35, 74, .92), rgba(7, 11, 26, .96));
}

.about-region p {
  max-width: 66ch;
}

.about-region__list {
  list-style: none;
  margin: clamp(18px, 2.4vw, 26px) 0 0;
  padding: 0;
  display: grid;
  gap: 12px;
}

.about-region__list li {
  position: relative;
  padding-left: 20px;
  font-size: 14px;
  line-height: 1.7;
  color: var(--mist);
}

.about-region__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 11px;
  width: 9px;
  height: 1px;
  background: var(--cyan);
}

/* ---------- 维护节奏 ---------- */
.about-cadence {
  list-style: none;
  margin: clamp(20px, 3vw, 28px) 0 0;
  padding: 0;
  border-top: 1px solid var(--about-line);
}

.about-cadence__row {
  display: grid;
  gap: 6px;
  padding: 18px 0;
  border-bottom: 1px solid var(--about-line);
}

.about-cadence__key {
  font-family: var(--font-serif);
  font-size: 13px;
  letter-spacing: .1em;
  color: var(--cyan);
}

.about-cadence__val {
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--text-hi);
  max-width: 62ch;
}

.about-outro {
  margin-top: clamp(26px, 3.6vw, 40px);
  padding: clamp(22px, 3vw, 34px);
  background: var(--track-blue);
  border-left: 3px solid var(--hot);
}

.about-outro p {
  margin: 0;
  max-width: 60ch;
  color: var(--text-hi);
  font-size: 15px;
}

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

/* ---------- 响应式 ---------- */
@media (min-width: 700px) {
  .about-points {
    grid-template-columns: repeat(3, minmax(0, 1fr));
  }

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

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

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

  .about-cadence__row {
    grid-template-columns: 132px minmax(0, 1fr);
    align-items: baseline;
    gap: 18px;
  }
}

@media (min-width: 900px) {
  .about-hero__inner {
    grid-template-columns: minmax(0, 1.06fr) minmax(0, .94fr);
  }

  .about-tl-wrap {
    grid-template-columns: minmax(0, 1fr) minmax(0, 320px);
    align-items: start;
  }
}

@media (min-width: 1000px) {
  .about-layout {
    display: grid;
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    gap: var(--about-gap);
    align-items: start;
  }

  .about-rail {
    position: sticky;
    top: calc(var(--bar-h) + 26px);
    margin-bottom: 0;
  }

  .about-rail__nav {
    flex-direction: column;
    gap: 2px;
    overflow: visible;
    padding-bottom: 0;
  }

  .about-rail .index-rail__link {
    padding: 9px 10px 9px 16px;
    border-color: transparent;
    border-left: 2px solid var(--about-line);
    white-space: normal;
  }

  .about-rail .index-rail__link[aria-current="true"] {
    color: var(--cyan);
    background: transparent;
    border-color: transparent;
    border-left-color: var(--cyan);
    font-weight: 600;
  }
}

@media (min-width: 1100px) {
  .about-flow__list {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }
}

/* ---------- 减少动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about * {
    animation-duration: .01ms !important;
    transition-duration: 120ms !important;
  }

  .about-hero::before {
    transform: none;
  }
}