.page-about {
  display: block;
  background: var(--deep-blue);
  color: var(--text);
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.7;
}

/* ===== 首屏 ===== */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  background:
    radial-gradient(900px 520px at 84% -6%, rgba(53, 229, 208, 0.16), transparent 62%),
    radial-gradient(700px 420px at 8% 110%, rgba(255, 106, 31, 0.14), transparent 66%),
    linear-gradient(155deg, var(--deep-blue) 0%, var(--night-blue) 100%);
  border-bottom: 1px solid var(--line);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -160px;
  left: -80px;
  width: 300px;
  height: 440px;
  background: linear-gradient(180deg, rgba(255, 106, 31, 0.26), rgba(226, 64, 43, 0));
  transform: skewY(-6deg);
  pointer-events: none;
}

.page-about .about-hero .breadcrumbs {
  position: relative;
  z-index: 2;
  padding-top: 22px;
}

.page-about .about-hero .breadcrumb-list {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--haze);
}

.page-about .about-hero .breadcrumb-list a {
  color: var(--cyan);
  text-decoration: none;
}

.page-about .about-hero .breadcrumb-list a:hover {
  text-decoration: underline;
}

.page-about .about-hero .breadcrumb-list li + li::before {
  content: "/";
  margin-right: 8px;
  color: var(--haze);
}

.page-about .about-hero__grid {
  position: relative;
  z-index: 2;
  display: grid;
  grid-template-columns: 1fr;
  gap: 30px;
  padding: 26px 0 32px;
}

.page-about .about-hero__eyebrow {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--cyan);
}

.page-about .about-hero__title {
  margin: 0 0 18px;
  font-family: var(--font-display);
  font-size: 34px;
  line-height: 1.16;
  letter-spacing: -0.02em;
  color: var(--text-strong);
}

.page-about .about-hero__lead {
  margin: 0 0 26px;
  font-size: 16px;
  line-height: 1.8;
  color: var(--text);
  max-width: 46em;
}

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

.page-about .about-hero__media {
  position: relative;
  margin: 0;
  border: 1px solid var(--line-cyan);
  box-shadow: var(--shadow);
  overflow: hidden;
  clip-path: polygon(0 6%, 100% 0, 100% 94%, 0 100%);
}

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

.page-about .about-hero__media::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, rgba(6, 14, 28, 0.12) 0%, rgba(6, 14, 28, 0.74) 100%);
  pointer-events: none;
}

.page-about .about-hero__stats {
  position: relative;
  z-index: 2;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin: 0 0 38px;
  padding: 0;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-stat {
  background: rgba(11, 27, 51, 0.9);
  padding: 16px 18px;
}

.page-about .about-stat dt {
  margin: 0 0 8px;
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--haze);
}

.page-about .about-stat dd {
  margin: 0;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 16px;
  color: var(--text);
  white-space: nowrap;
}

.page-about .about-stat dd .num {
  display: inline-block;
  margin-right: 4px;
  font-size: 26px;
  font-weight: 700;
  color: var(--orange);
  line-height: 1;
}

/* ===== 章节导航轨道 ===== */
.page-about .about-rail {
  position: sticky;
  top: 0;
  z-index: 6;
  background: rgba(6, 14, 28, 0.9);
  border-bottom: 1px solid var(--line);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
}

.page-about .about-rail__list {
  display: flex;
  align-items: stretch;
  gap: 2px;
  margin: 0;
  padding: 0;
  list-style: none;
  overflow-x: auto;
  -webkit-overflow-scrolling: touch;
  scrollbar-width: none;
}

.page-about .about-rail__list::-webkit-scrollbar {
  display: none;
}

.page-about .about-rail__link {
  display: inline-flex;
  align-items: baseline;
  gap: 7px;
  padding: 17px 13px;
  white-space: nowrap;
  color: var(--haze);
  text-decoration: none;
  border-bottom: 2px solid transparent;
  transition: color 180ms var(--ease), border-color 180ms var(--ease), background 180ms var(--ease);
}

.page-about .about-rail__link:hover {
  color: var(--text-strong);
  background: rgba(255, 255, 255, 0.05);
}

.page-about .about-rail__link:focus-visible {
  outline: 2px solid var(--orange);
  outline-offset: -2px;
}

.page-about .about-rail__num {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--orange);
}

.page-about .about-rail__name {
  font-size: 13px;
  letter-spacing: 0.08em;
}

/* ===== 章节通用 ===== */
.page-about .about-chapter {
  position: relative;
  border-bottom: 1px solid var(--line);
  scroll-margin-top: 62px;
}

.page-about .about-chapter[data-chapter="01"] { --band: 16%; }
.page-about .about-chapter[data-chapter="02"] { --band: 27%; }
.page-about .about-chapter[data-chapter="03"] { --band: 38%; }
.page-about .about-chapter[data-chapter="04"] { --band: 51%; }
.page-about .about-chapter[data-chapter="05"] { --band: 63%; }
.page-about .about-chapter[data-chapter="06"] { --band: 76%; }
.page-about .about-chapter[data-chapter="07"] { --band: 88%; }

.page-about .about-chapter__inner {
  padding: 46px 0 52px;
}

.page-about .about-chapter__band {
  display: block;
  width: var(--band, 24%);
  max-width: 100%;
  height: 4px;
  margin-bottom: 22px;
  background: linear-gradient(90deg, var(--red-orange), var(--orange) 70%, rgba(255, 106, 31, 0.15));
  transition: width 320ms var(--ease);
}

.page-about .about-chapter__head {
  display: grid;
  grid-template-columns: 1fr;
  gap: 6px;
  margin-bottom: 26px;
}

.page-about .about-chapter__number {
  display: block;
  font-family: var(--font-mono);
  font-size: 68px;
  font-weight: 800;
  line-height: 0.86;
  letter-spacing: -0.05em;
  color: rgba(143, 163, 191, 0.26);
  transition: color 300ms var(--ease);
}

@supports (-webkit-text-stroke: 1px #000) {
  .page-about .about-chapter__number {
    color: transparent;
    -webkit-text-stroke: 2px rgba(143, 163, 191, 0.48);
  }
  .page-about .about-chapter.is-current .about-chapter__number {
    -webkit-text-stroke-color: var(--orange);
  }
}

.page-about .about-chapter.is-current .about-chapter__band {
  box-shadow: 0 0 0 1px rgba(255, 106, 31, 0.35);
}

.page-about .about-chapter__eyebrow {
  margin: 0 0 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.22em;
  color: var(--cyan);
}

.page-about .about-chapter__title {
  margin: 0;
  font-family: var(--font-display);
  font-size: 24px;
  line-height: 1.28;
  letter-spacing: -0.015em;
  color: var(--text-strong);
}

.page-about .about-prose {
  font-size: 16px;
  line-height: 1.88;
  color: var(--text);
  max-width: 54em;
}

.page-about .about-prose p {
  margin: 0 0 16px;
}

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

.page-about .about-prose--lead {
  margin: 0 0 26px;
  font-size: 17px;
  color: var(--text-strong);
}

.page-about .about-linkline {
  margin: 26px 0 0;
  font-size: 15px;
  color: var(--haze);
}

.page-about .about-linkline a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(53, 229, 208, 0.4);
}

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

.page-about .about-quote {
  margin: 28px 0 0;
  padding: 24px 26px;
  background: var(--cream);
  color: var(--ink);
  border-left: 6px solid var(--orange);
  font-size: 17px;
  line-height: 1.82;
  max-width: 42em;
}

/* ===== 01 要点列表 ===== */
.page-about .about-points {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  margin: 28px 0 0;
  padding: 0;
  list-style: none;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-point {
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 16px 18px;
  background: rgba(11, 27, 51, 0.72);
}

.page-about .about-point__key {
  flex: 0 0 auto;
  min-width: 92px;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 22px;
  font-weight: 700;
  color: var(--gold);
}

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

/* ===== 02 指标卡 ===== */
.page-about .about-metrics {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
  margin: 28px 0 0;
}

.page-about .about-metric {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 20px;
  background: var(--glass);
  border: 1px solid var(--line);
  border-top: 3px solid var(--cyan);
}

.page-about .about-metric__num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 34px;
  font-weight: 700;
  line-height: 1;
  color: var(--text-strong);
}

.page-about .about-metric__unit {
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--cyan);
}

.page-about .about-metric__label {
  margin-top: 8px;
  font-size: 14px;
  color: var(--haze);
}

/* ===== 图片通用 ===== */
.page-about .about-figure {
  position: relative;
  margin: 32px 0 0;
  border: 1px solid var(--line);
  background: rgba(6, 14, 28, 0.6);
  overflow: hidden;
}

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

.page-about .about-figure__cap {
  padding: 12px 16px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--haze);
  border-top: 1px solid var(--line);
}

/* ===== 03 双栏 + 侧栏 ===== */
.page-about .about-chapter__body--split {
  display: grid;
  grid-template-columns: 1fr;
  gap: 26px;
}

.page-about .about-aside {
  padding: 22px;
  background: rgba(6, 14, 28, 0.72);
  border: 1px solid var(--line-cyan);
  border-left: 3px solid var(--orange);
}

.page-about .about-aside__title {
  margin: 0 0 14px;
  font-size: 13px;
  letter-spacing: 0.14em;
  color: var(--gold);
}

.page-about .about-aside__list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: grid;
  gap: 12px;
}

.page-about .about-aside__list li {
  position: relative;
  padding-left: 18px;
  font-size: 15px;
  line-height: 1.7;
  color: var(--text);
}

.page-about .about-aside__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  width: 8px;
  height: 2px;
  background: var(--cyan);
}

/* ===== 04 里程碑 ===== */
.page-about .about-milestones {
  position: relative;
  margin: 0;
  padding: 0 0 0 26px;
  list-style: none;
  display: grid;
  gap: 26px;
  border-left: 1px solid var(--line-cyan);
}

.page-about .about-milestone {
  position: relative;
  padding: 20px 22px;
  background: rgba(11, 27, 51, 0.7);
  border: 1px solid var(--line);
}

.page-about .about-milestone__dot {
  position: absolute;
  left: -33px;
  top: 26px;
  width: 12px;
  height: 12px;
  border-radius: 50%;
  background: var(--night-blue);
  border: 2px solid var(--cyan);
}

.page-about .about-milestone:hover .about-milestone__dot {
  background: var(--orange);
  border-color: var(--orange);
}

.page-about .about-milestone__tag {
  display: inline-block;
  margin: 0 0 10px;
  padding: 2px 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--night-blue);
  background: var(--gold);
}

.page-about .about-milestone__title {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: 19px;
  line-height: 1.4;
  color: var(--text-strong);
}

.page-about .about-milestone__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.85;
  color: var(--text);
  max-width: 44em;
}

.page-about .about-milestone__hint {
  display: inline-block;
  margin-top: 14px;
  padding: 3px 10px;
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--cyan);
  border: 1px solid var(--line-cyan);
  opacity: 0;
  transform: translateY(4px);
  transition: opacity 200ms var(--ease), transform 200ms var(--ease);
}

.page-about .about-milestone:hover .about-milestone__hint,
.page-about .about-milestone:focus-within .about-milestone__hint {
  opacity: 1;
  transform: translateY(0);
}

/* ===== 05 团队 ===== */
.page-about .about-team {
  display: grid;
  gap: 22px;
}

.page-about .about-roles {
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-role {
  display: grid;
  grid-template-columns: auto 1fr;
  grid-template-areas:
    "num name"
    "num desc";
  align-items: center;
  column-gap: 16px;
  padding: 14px 18px;
  background: rgba(11, 27, 51, 0.82);
}

.page-about .about-role__num {
  grid-area: num;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 28px;
  font-weight: 700;
  color: var(--orange);
  line-height: 1;
}

.page-about .about-role__name {
  grid-area: name;
  font-size: 15px;
  color: var(--text-strong);
}

.page-about .about-role__desc {
  grid-area: desc;
  font-size: 13px;
  color: var(--haze);
}

/* ===== 06 数据格 ===== */
.page-about .about-map {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin-top: 30px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-map__cell {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 20px 18px;
  background: rgba(6, 14, 28, 0.78);
}

.page-about .about-map__num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: 30px;
  font-weight: 700;
  line-height: 1;
  color: var(--text-strong);
}

.page-about .about-map__unit {
  margin-left: 2px;
  font-size: 15px;
  color: var(--orange);
}

.page-about .about-map__label {
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--haze);
}

/* ===== 07 收束 ===== */
.page-about .about-chapter--final .about-chapter__inner {
  max-width: 880px;
  margin: 0 auto;
  padding-bottom: 64px;
}

.page-about .about-next {
  display: grid;
  grid-template-columns: 1fr;
  gap: 18px;
  margin-top: 30px;
}

.page-about .about-next__item {
  padding: 22px;
  background: var(--glass);
  border: 1px solid var(--line);
  border-top: 3px solid var(--gold);
}

.page-about .about-next__idx {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--gold);
}

.page-about .about-next__title {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-size: 19px;
  line-height: 1.42;
  color: var(--text-strong);
}

.page-about .about-next__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.82;
  color: var(--text);
}

.page-about .about-closing {
  margin: 34px 0 0;
  padding: 24px 26px;
  background: var(--cream);
  color: var(--ink);
  border-left: 6px solid var(--red-orange);
  font-size: 17px;
  line-height: 1.85;
}

/* ===== 收尾 CTA ===== */
.page-about .about-cta {
  position: relative;
  overflow: hidden;
  background:
    radial-gradient(760px 380px at 12% 0%, rgba(53, 229, 208, 0.14), transparent 60%),
    linear-gradient(160deg, var(--night-blue) 0%, var(--deep-blue) 100%);
  border-top: 1px solid var(--line-cyan);
}

.page-about .about-cta::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: min(60%, 520px);
  height: 6px;
  background: linear-gradient(90deg, var(--orange), var(--red-orange));
  transform: skewX(-6deg);
  transform-origin: left top;
}

.page-about .about-cta__inner {
  padding: 48px 0 56px;
}

.page-about .about-cta__title {
  margin: 0 0 16px;
  font-family: var(--font-display);
  font-size: 26px;
  line-height: 1.28;
  letter-spacing: -0.015em;
  color: var(--text-strong);
}

.page-about .about-cta__text {
  margin: 0 0 26px;
  max-width: 46em;
  font-size: 16px;
  line-height: 1.85;
  color: var(--text);
}

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

.page-about .about-cta__note {
  margin: 22px 0 0;
  font-size: 14px;
  color: var(--haze);
}

.page-about .about-cta__note a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(53, 229, 208, 0.4);
}

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

/* ===== 响应式 ===== */
@media (min-width: 640px) {
  .page-about .about-hero__title {
    font-size: 42px;
  }

  .page-about .about-hero__stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    margin-bottom: 48px;
  }

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

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

  .page-about .about-point {
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
  }

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

  .page-about .about-role {
    grid-template-columns: 1fr;
    grid-template-areas:
      "num"
      "name"
      "desc";
    row-gap: 6px;
  }

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

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

  .page-about .about-cta__title {
    font-size: 32px;
  }
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.08fr) minmax(0, 0.92fr);
    gap: 48px;
    align-items: center;
    padding: 34px 0 40px;
  }

  .page-about .about-hero__title {
    font-size: 56px;
    line-height: 1.12;
  }

  .page-about .about-hero__lead {
    font-size: 17px;
  }

  .page-about .about-chapter__inner {
    padding: 62px 0 70px;
  }

  .page-about .about-chapter__head {
    grid-template-columns: 232px minmax(0, 1fr);
    gap: 36px;
    align-items: start;
    margin-bottom: 34px;
  }

  .page-about .about-chapter__number {
    font-size: 124px;
  }

  .page-about .about-chapter__title {
    font-size: 30px;
  }

  .page-about .about-chapter__body {
    padding-left: 268px;
  }

  .page-about .about-chapter--final .about-chapter__body {
    padding-left: 0;
  }

  .page-about .about-chapter__body--split {
    grid-template-columns: minmax(0, 1.35fr) minmax(0, 0.85fr);
    gap: 36px;
    align-items: start;
  }

  .page-about .about-chapter__body--flip {
    grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.35fr);
  }

  .page-about .about-chapter__body--split .about-figure {
    margin-top: 4px;
  }

  .page-about .about-figure--wide {
    margin-left: -268px;
  }

  .page-about .about-team {
    gap: 26px;
  }

  .page-about .about-cta__inner {
    padding: 68px 0 76px;
  }

  .page-about .about-cta__title {
    font-size: 40px;
  }
}

@media (min-width: 1120px) {
  .page-about .about-chapter__number {
    font-size: 138px;
  }

  .page-about .about-milestones {
    padding-left: 34px;
  }

  .page-about .about-milestone__dot {
    left: -41px;
  }
}