.page-about {
  --about-pad: clamp(18px, 5vw, 64px);
  --about-max: 1320px;
  background: var(--ink);
  color: var(--paper);
  font-family: var(--font-sans);
}

.page-about a {
  color: inherit;
  text-decoration: none;
}

.page-about .about-cap {
  display: block;
  padding: 10px var(--about-pad);
  background: var(--ink-soft);
  border-bottom: 1px solid var(--hair);
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.06em;
  color: var(--mist);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  border-bottom: 1px solid var(--hair);
  background:
    radial-gradient(130% 100% at 94% -20%, rgba(255, 106, 43, 0.2), rgba(255, 106, 43, 0) 62%),
    radial-gradient(100% 90% at -10% 120%, rgba(15, 46, 35, 0.85), rgba(15, 46, 35, 0) 70%),
    var(--ink);
}

.page-about .about-hero__inner {
  position: relative;
  z-index: 1;
  max-width: var(--about-max);
  margin: 0 auto;
  padding: clamp(26px, 5vw, 52px) var(--about-pad) clamp(30px, 6vw, 60px);
}

.page-about .about-hero__crumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  letter-spacing: 0.08em;
  color: var(--mist);
}

.page-about .about-hero__crumb a {
  color: var(--mist);
  border-bottom: 1px solid transparent;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-hero__crumb a:hover,
.page-about .about-hero__crumb a:focus-visible {
  color: var(--orange);
  border-bottom-color: var(--orange);
}

.page-about .about-hero__eyebrow {
  margin: clamp(20px, 4vw, 34px) 0 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--lemon);
}

.page-about .about-hero__ghost {
  position: absolute;
  right: calc(var(--about-pad) * 0.4);
  top: clamp(6px, 2vw, 20px);
  font-family: var(--font-mono);
  font-size: clamp(5rem, 20vw, 15rem);
  line-height: 0.82;
  letter-spacing: -0.02em;
  color: rgba(216, 255, 62, 0.07);
  pointer-events: none;
  user-select: none;
}

.page-about .about-hero__title {
  position: relative;
  margin: 12px 0 0;
  max-width: 16ch;
  font-size: clamp(2rem, 7.2vw, 4.6rem);
  font-weight: 900;
  line-height: 1.12;
  letter-spacing: 0.03em;
  color: var(--paper);
}

.page-about .about-hero__lead {
  margin: clamp(16px, 3vw, 24px) 0 0;
  max-width: 48ch;
  font-size: clamp(0.98rem, 2.2vw, 1.12rem);
  line-height: 1.85;
  color: var(--mist);
}

.page-about .about-hero__jump {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin-top: clamp(22px, 4vw, 34px);
  padding-top: 18px;
  border-top: 1px solid var(--hair);
}

.page-about .about-hero__jump-link {
  display: inline-flex;
  align-items: center;
  padding: 8px 13px;
  border: 1px solid var(--hair);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--paper);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .about-hero__jump-link:hover,
.page-about .about-hero__jump-link:focus-visible {
  color: var(--orange);
  border-color: var(--orange);
  background: rgba(255, 106, 43, 0.08);
}

.page-about .about-hero__figure {
  margin: 0;
  border-top: 1px solid var(--hair);
  background: var(--ink-soft);
}

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

/* ---------- 主体骨架 ---------- */
.page-about .about-body {
  max-width: var(--about-max);
  margin: 0 auto;
  padding: clamp(34px, 6vw, 72px) var(--about-pad) clamp(48px, 7vw, 96px);
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 5vw, 48px);
}

.page-about .about-flow {
  min-width: 0;
}

@media (min-width: 880px) {
  .page-about .about-body {
    grid-template-columns: 176px minmax(0, 1fr);
    gap: clamp(32px, 5vw, 72px);
    align-items: start;
  }
}

/* ---------- 章节索引 ---------- */
.page-about .about-toc {
  border-top: 2px solid var(--orange);
  padding-top: 12px;
  min-width: 0;
}

.page-about .about-toc__title {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.18em;
  color: var(--lemon);
}

.page-about .about-toc__list {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-toc__link {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 10px;
  border: 1px solid var(--hair);
  font-size: 13px;
  color: var(--mist);
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .about-toc__index {
  font-family: var(--font-mono);
  font-size: 11px;
  color: var(--lemon);
}

.page-about .about-toc__link:hover,
.page-about .about-toc__link:focus-visible {
  color: var(--paper);
  border-color: var(--orange);
  background: rgba(255, 106, 43, 0.07);
}

@media (min-width: 880px) {
  .page-about .about-toc {
    position: sticky;
    top: calc(var(--bar-h) + var(--rail-h) + 20px);
    align-self: start;
  }

  .page-about .about-toc__list {
    flex-direction: column;
    gap: 0;
  }

  .page-about .about-toc__link {
    width: 100%;
    border: 0;
    border-left: 1px solid var(--hair);
    padding: 7px 0 7px 12px;
  }

  .page-about .about-toc__link:hover,
  .page-about .about-toc__link:focus-visible {
    border-left-color: var(--orange);
    background: transparent;
  }
}

/* ---------- 章节通用 ---------- */
.page-about .about-sec {
  min-width: 0;
}

.page-about .about-sec + .about-sec {
  margin-top: clamp(40px, 7vw, 84px);
  padding-top: clamp(26px, 5vw, 46px);
  border-top: 1px solid var(--hair);
}

.page-about .about-sec__head {
  display: grid;
  gap: 8px;
  margin-bottom: clamp(16px, 3vw, 26px);
}

.page-about .about-sec__num {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--orange);
}

.page-about .about-sec__title {
  margin: 0;
  font-size: clamp(1.5rem, 4.4vw, 2.4rem);
  font-weight: 800;
  line-height: 1.24;
  letter-spacing: 0.02em;
  color: var(--paper);
}

.page-about .about-sec__lead {
  margin: 0;
  max-width: 46ch;
  font-size: 0.98rem;
  line-height: 1.8;
  color: var(--mist);
}

.page-about .about-p {
  margin: 0 0 14px;
  font-size: 0.98rem;
  line-height: 1.85;
  color: rgba(245, 241, 232, 0.84);
}

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

.page-about .about-note {
  display: grid;
  gap: 5px;
  margin-top: 20px;
  padding: 14px 16px;
  background: var(--ink-soft);
  border-left: 2px solid var(--lemon);
}

.page-about .about-note__k {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--lemon);
}

.page-about .about-note__v {
  font-size: 14px;
  line-height: 1.75;
  color: var(--paper);
}

/* ---------- 版本时间轴 ---------- */
.page-about .tl {
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .tl__item {
  position: relative;
  padding-left: 30px;
  padding-bottom: 16px;
}

.page-about .tl__item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 20px;
  width: 9px;
  height: 9px;
  background: var(--orange);
  border-radius: 2px;
  box-shadow: 0 0 0 3px rgba(255, 106, 43, 0.16);
}

.page-about .tl__item:not(:last-child)::after {
  content: "";
  position: absolute;
  left: 4px;
  top: 34px;
  bottom: 0;
  width: 1px;
  background: var(--hair);
}

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

.page-about .tl__card {
  border: 1px solid var(--hair);
  background: rgba(19, 25, 23, 0.72);
  transition: border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .tl__card:hover,
.page-about .tl__card:focus-within,
.page-about .tl__card[open] {
  border-color: var(--orange);
  background: var(--ink-soft);
}

.page-about .tl__sum {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 10px 12px;
  padding: 14px 16px;
  cursor: pointer;
  list-style: none;
}

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

.page-about .tl__sum::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 15px;
  color: var(--mist);
}

.page-about .tl__card[open] .tl__sum::after {
  content: "–";
  color: var(--orange);
}

.page-about .tl__ver {
  display: inline-block;
  padding: 3px 8px;
  border: 1px solid currentColor;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
}

.page-about .tl__ver--legacy {
  color: var(--steel);
}

.page-about .tl__ver--new {
  color: var(--orange);
}

.page-about .tl__title {
  font-size: 1rem;
  font-weight: 700;
  line-height: 1.5;
  color: var(--paper);
}

.page-about .tl__body {
  padding: 0 16px 16px;
  font-size: 14.5px;
  line-height: 1.82;
  color: var(--mist);
}

.page-about .tl__body p {
  margin: 0;
}

.page-about .tl__facts {
  display: grid;
  gap: 8px;
  margin: 14px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .tl__facts li {
  position: relative;
  padding-left: 16px;
  font-size: 13.5px;
  line-height: 1.7;
  color: var(--paper);
}

.page-about .tl__facts li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 9px;
  width: 6px;
  height: 1px;
  background: var(--lemon);
}

/* ---------- 团队分工 ---------- */
.page-about .crew {
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--hair);
}

.page-about .crew__row {
  display: grid;
  gap: 4px;
  padding: 14px 0;
  border-bottom: 1px solid var(--hair);
  transition: background var(--dur) var(--ease);
}

.page-about .crew__row:hover {
  background: rgba(255, 106, 43, 0.06);
}

.page-about .crew__k {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 14px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .crew__k::before {
  content: "";
  flex: none;
  width: 5px;
  height: 5px;
  background: var(--lemon);
}

.page-about .crew__v {
  font-size: 14.5px;
  line-height: 1.8;
  color: var(--mist);
}

@media (min-width: 700px) {
  .page-about .crew__row {
    grid-template-columns: 118px minmax(0, 1fr);
    gap: 20px;
    align-items: baseline;
  }
}

/* ---------- 图片 ---------- */
.page-about .about-fig {
  margin: clamp(20px, 4vw, 30px) 0 0;
}

.page-about .about-fig__img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  border: 1px solid var(--hair);
  background: var(--ink-soft);
  object-fit: cover;
}

.page-about .about-fig__cap {
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 11.5px;
  line-height: 1.6;
  letter-spacing: 0.05em;
  color: var(--mist);
}

/* ---------- 服务规模 ---------- */
.page-about .scale-band {
  margin-top: clamp(18px, 3vw, 26px);
  padding: clamp(20px, 4vw, 34px);
  border: 1px solid var(--hair);
  border-top: 2px solid var(--orange);
  background:
    linear-gradient(158deg, rgba(20, 56, 43, 0.95), rgba(11, 15, 14, 0.97));
}

.page-about .scale-band__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(126px, 1fr));
  gap: 16px 14px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .scale-item {
  display: grid;
  gap: 4px;
  padding-top: 10px;
  border-top: 1px solid rgba(245, 241, 232, 0.12);
}

.page-about .scale-item__num {
  font-family: var(--font-mono);
  font-size: clamp(1.6rem, 4.6vw, 2.3rem);
  font-weight: 500;
  line-height: 1;
  color: var(--paper);
  transition: color var(--dur) var(--ease);
}

.page-about .scale-item__unit {
  margin-left: 2px;
  font-size: 0.5em;
  color: var(--lemon);
}

.page-about .scale-item__label {
  font-size: 13px;
  font-weight: 600;
  color: var(--paper);
}

.page-about .scale-item__note {
  font-family: var(--font-mono);
  font-size: 11px;
  line-height: 1.6;
  color: var(--steel);
  transition: color var(--dur) var(--ease);
}

.page-about .scale-item:hover .scale-item__num {
  color: var(--lemon);
}

.page-about .scale-item:hover .scale-item__note {
  color: var(--mist);
}

.page-about .scale-band__foot {
  margin: 20px 0 0;
  padding-top: 14px;
  border-top: 1px solid rgba(245, 241, 232, 0.12);
  font-size: 13px;
  line-height: 1.75;
  color: var(--mist);
}

/* ---------- 看台文化 ---------- */
.page-about .culture-list {
  display: grid;
  gap: 16px;
  margin: clamp(18px, 3vw, 26px) 0;
  padding: 0;
  list-style: none;
}

.page-about .culture-list__item {
  padding-top: 12px;
  border-top: 2px solid var(--orange);
}

.page-about .culture-list__k {
  display: block;
  margin-bottom: 6px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.1em;
  color: var(--lemon);
}

.page-about .culture-list__v {
  display: block;
  font-size: 14px;
  line-height: 1.8;
  color: var(--mist);
}

@media (min-width: 760px) {
  .page-about .culture-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 20px;
  }
}

/* ---------- 下一步 ---------- */
.page-about .next-grid {
  display: grid;
  gap: 14px;
  margin-top: clamp(16px, 3vw, 24px);
}

@media (min-width: 760px) {
  .page-about .next-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
    gap: 18px;
  }
}

.page-about .next-card {
  display: flex;
  flex-direction: column;
  gap: 9px;
  padding: clamp(18px, 3vw, 26px);
  border: 1px solid var(--hair);
  background: rgba(19, 25, 23, 0.6);
  transition: border-color var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .next-card:hover,
.page-about .next-card:focus-visible {
  border-color: var(--orange);
  background: var(--ink-soft);
}

.page-about .next-card__k {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.16em;
  color: var(--lemon);
}

.page-about .next-card__title {
  font-size: 1.1rem;
  font-weight: 700;
  line-height: 1.5;
  color: var(--paper);
}

.page-about .next-card__text {
  font-size: 14px;
  line-height: 1.78;
  color: var(--mist);
}

.page-about .next-card__link {
  margin-top: auto;
  padding-top: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--orange);
}

.page-about .next-card:hover .next-card__link,
.page-about .next-card:focus-visible .next-card__link {
  color: var(--lemon);
}

.page-about .next-note {
  margin: clamp(18px, 3vw, 24px) 0 0;
  font-size: 14px;
  line-height: 1.85;
  color: var(--mist);
}

.page-about .next-note a {
  color: var(--paper);
  border-bottom: 1px solid var(--orange);
  transition: color var(--dur) var(--ease);
}

.page-about .next-note a:hover,
.page-about .next-note a:focus-visible {
  color: var(--orange);
}

@media (prefers-reduced-motion: reduce) {
  .page-about *,
  .page-about *::before,
  .page-about *::after {
    transition-duration: 1ms !important;
  }
}