.page-about {
  --about-radius: var(--radius);
  background: var(--ink);
  color: var(--sand);
}

/* ---------- 首屏 ---------- */
.page-about .about-intro {
  position: relative;
  padding: clamp(1.25rem, 3vw, 2rem) 0 clamp(2.25rem, 6vw, 4rem);
  overflow: hidden;
}

.page-about .about-intro::before {
  content: "";
  position: absolute;
  top: -180px;
  left: -10%;
  right: -10%;
  height: 460px;
  background:
    radial-gradient(45% 55% at 22% 40%, rgba(139, 75, 255, 0.30), transparent 70%),
    radial-gradient(38% 48% at 82% 18%, rgba(43, 231, 214, 0.16), transparent 72%);
  pointer-events: none;
  z-index: 0;
}

.page-about .about-intro .container {
  position: relative;
  z-index: 1;
}

.page-about .about-intro__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.5rem, 4vw, 3rem);
  margin-top: clamp(1.25rem, 3vw, 2rem);
}

.page-about .about-intro__lead .display-title {
  margin: 0.6rem 0 1rem;
  max-width: 20ch;
  text-shadow: 0 0 26px rgba(139, 75, 255, 0.36);
}

.page-about .about-intro__lead .lede {
  max-width: 46ch;
  margin: 0;
}

.page-about .about-intro__side {
  padding: 1.15rem 1.25rem 0.6rem;
  border: 1px solid var(--line);
  border-radius: var(--about-radius);
  background: var(--glass);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.page-about .about-intro__sidetitle {
  margin: 0 0 0.5rem;
  font-family: var(--font-mono);
  font-size: 0.6875rem;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  color: var(--neon);
}

.page-about .about-facts {
  margin: 0;
  padding: 0;
}

.page-about .about-fact {
  display: flex;
  align-items: baseline;
  gap: 0.85rem;
  padding: 0.7rem 0;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-fact:last-child {
  border-bottom: 0;
}

.page-about .about-fact__k {
  flex: 0 0 auto;
  font-family: var(--font-mono);
  font-size: 1.5rem;
  font-weight: 700;
  line-height: 1;
  color: var(--cyan);
  letter-spacing: -0.01em;
}

.page-about .about-fact__l {
  margin: 0;
  font-size: 0.8125rem;
  line-height: 1.5;
  color: var(--mist);
}

/* ---------- 章节目录 ---------- */
.page-about .about-index {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem 0.5rem;
  padding-top: 0.85rem;
  padding-bottom: 0.85rem;
  margin-bottom: clamp(1.75rem, 5vw, 3.25rem);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.page-about .about-index__link {
  display: inline-flex;
  align-items: center;
  gap: 0.45rem;
  padding: 0.35rem 0.7rem;
  font-size: 0.8125rem;
  color: var(--mist);
  text-decoration: none;
  border: 1px solid transparent;
  border-radius: 999px;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease), background 0.18s var(--ease);
}

.page-about .about-index__link:hover,
.page-about .about-index__link:focus-visible {
  color: var(--sand);
  border-color: var(--line);
  background: var(--glass);
}

.page-about .about-index__link.is-active {
  color: var(--cyan);
  border-color: rgba(43, 231, 214, 0.55);
}

.page-about .about-index__num {
  font-size: 0.6875rem;
  color: var(--violet);
}

/* ---------- 通用章节 ---------- */
.page-about .about-sec {
  padding: clamp(1.75rem, 5vw, 4rem) 0;
}

.page-about .about-sec__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.25rem, 3vw, 2.5rem);
}

.page-about .about-sec__head {
  display: block;
}

.page-about .about-sec__num {
  display: block;
  font-size: clamp(2rem, 5.5vw, 3rem);
  font-weight: 800;
  line-height: 1;
  letter-spacing: 0.01em;
  color: var(--violet);
  margin-bottom: 0.55rem;
  text-shadow: 0 0 20px rgba(139, 75, 255, 0.45);
}

.page-about .about-sec__num--onruby {
  color: rgba(245, 241, 232, 0.55);
  text-shadow: none;
}

.page-about .about-sec__title {
  margin: 0 0 0.7rem;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(1.3rem, 2.6vw, 1.8rem);
  line-height: 1.3;
  color: var(--sand);
}

.page-about .about-sec__title--onruby {
  margin-bottom: 1.5rem;
}

.page-about .about-sec__note {
  margin: 0;
  padding-left: 0.85rem;
  border-left: 1px solid var(--line);
  font-family: var(--font-serif);
  font-size: 0.8125rem;
  line-height: 1.8;
  color: var(--mist);
}

.page-about .about-sec__head--wide {
  margin-bottom: clamp(1.5rem, 4vw, 2.5rem);
}

.page-about .about-sec__body > p {
  margin: 0 0 1.05rem;
  max-width: 62ch;
  font-size: 1rem;
  line-height: 1.85;
  color: var(--sand);
}

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

.page-about .about-sec__body .mono {
  color: var(--cyan);
  font-weight: 700;
}

/* ---------- 时间线 ---------- */
.page-about .about-tl-wrap {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.5rem, 3vw, 2.5rem);
}

.page-about .about-tl-figure {
  margin: 0;
}

.page-about .about-tl {
  position: relative;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-tl::before {
  content: "";
  position: absolute;
  left: 5px;
  top: 0.7rem;
  bottom: 0.7rem;
  width: 1px;
  background: linear-gradient(180deg, var(--cyan) 0%, var(--violet) 55%, rgba(43, 231, 214, 0) 100%);
  opacity: 0.6;
}

.page-about .about-tl__item {
  display: grid;
  grid-template-columns: 1rem 3.6rem minmax(0, 1fr);
  column-gap: 0.6rem;
  padding-bottom: 1.6rem;
  outline: none;
}

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

.page-about .about-tl__dot {
  grid-column: 1;
  grid-row: 1;
  width: 11px;
  height: 11px;
  margin-top: 0.3rem;
  border-radius: 50%;
  background: var(--ink);
  border: 1px solid var(--cyan);
  box-shadow: 0 0 0 3px rgba(43, 231, 214, 0.12);
  transition: background 0.2s var(--ease), box-shadow 0.2s var(--ease);
}

.page-about .about-tl__year {
  grid-column: 2;
  grid-row: 1;
  font-family: var(--font-mono);
  font-size: 0.875rem;
  letter-spacing: 0.04em;
  color: var(--cyan);
}

.page-about .about-tl__title {
  grid-column: 3;
  grid-row: 1;
  margin: 0 0 0.3rem;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.0625rem;
  line-height: 1.4;
  color: var(--sand);
}

.page-about .about-tl__text {
  grid-column: 3;
  grid-row: 2;
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.7;
  color: var(--mist);
  transition: color 0.22s var(--ease);
}

/* ---------- 团队分工 ---------- */
.page-about .about-team-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.5rem, 3vw, 2.5rem);
}

.page-about .about-team-figure {
  margin: 0;
}

.page-about .about-team {
  display: grid;
  gap: 0.75rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-team__item {
  padding: 1rem 1.15rem;
  border-left: 2px solid var(--violet);
  border-radius: 0 var(--about-radius) var(--about-radius) 0;
  background: var(--glass);
  transition: background 0.2s var(--ease), transform 0.2s var(--ease), border-color 0.2s var(--ease);
}

.page-about .about-team__item:hover {
  background: var(--glass-strong);
  border-left-color: var(--cyan);
  transform: translateX(2px);
}

.page-about .about-team__name {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 0.55rem;
  margin: 0 0 0.4rem;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1rem;
  color: var(--sand);
}

.page-about .about-team__count {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  font-weight: 400;
  letter-spacing: 0.06em;
  color: var(--lava);
}

.page-about .about-team__desc {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--mist);
}

.page-about .about-team__desc .mono,
.page-about .about-local__text .mono {
  color: var(--cyan);
  font-weight: 700;
}

/* ---------- 更新节奏 ---------- */
.page-about .about-sec--cadence {
  background: var(--teal);
  border-top: 1px solid var(--line);
  border-bottom: 1px solid var(--line);
}

.page-about .about-cadence__cols {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0 1.75rem;
  margin-top: 1.75rem;
}

.page-about .about-cadence__col {
  padding: 0.9rem 0 1rem;
  border-top: 1px solid rgba(43, 231, 214, 0.22);
}

.page-about .about-cadence__coltitle {
  margin: 0 0 0.4rem;
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  color: var(--neon);
}

.page-about .about-cadence__coltext {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.7;
  color: rgba(245, 241, 232, 0.82);
}

.page-about .about-cadence__more {
  margin: 1.5rem 0 0;
}

.page-about .index-link {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(43, 231, 214, 0.4);
  padding-bottom: 1px;
  transition: color 0.18s var(--ease), border-color 0.18s var(--ease);
}

.page-about .index-link:hover,
.page-about .index-link:focus-visible {
  color: var(--sand);
  border-bottom-color: var(--sand);
}

/* ---------- 线下与本地 ---------- */
.page-about .about-local {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(1.5rem, 3vw, 2.5rem);
}

.page-about .about-local__text .about-sec__num {
  margin-bottom: 0.5rem;
}

.page-about .about-local__text > p {
  margin: 0 0 1rem;
  max-width: 60ch;
  font-size: 1rem;
  line-height: 1.85;
  color: var(--sand);
}

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

/* ---------- 四件事 ---------- */
.page-about .about-principles {
  position: relative;
  overflow: hidden;
  padding: clamp(1.5rem, 4vw, 3rem);
  border-radius: var(--about-radius);
  background: linear-gradient(155deg, var(--ruby) 0%, #6d0d2e 100%);
}

.page-about .about-principles::after {
  content: "";
  position: absolute;
  right: -12%;
  bottom: -35%;
  width: 340px;
  height: 340px;
  border-radius: 50%;
  background: radial-gradient(circle, rgba(245, 241, 232, 0.16), transparent 66%);
  pointer-events: none;
}

.page-about .about-principles__list {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1.35rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-principles__item {
  padding-top: 0.9rem;
  border-top: 1px solid rgba(245, 241, 232, 0.28);
}

.page-about .about-principles__num {
  display: block;
  margin-bottom: 0.35rem;
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  color: var(--neon);
}

.page-about .about-principles__title {
  margin: 0 0 0.4rem;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.0625rem;
  line-height: 1.4;
  color: var(--sand);
}

.page-about .about-principles__text {
  margin: 0;
  max-width: 40ch;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: rgba(245, 241, 232, 0.85);
}

/* ---------- 收束 ---------- */
.page-about .about-cta-wrap {
  padding: clamp(2rem, 5vw, 3.5rem) 0 clamp(2.5rem, 7vw, 5rem);
}

.page-about .about-cta {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 1.25rem 2rem;
  padding: clamp(1.25rem, 3vw, 2rem);
  border: 1px solid var(--line);
  border-radius: var(--about-radius);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
}

.page-about .about-cta__text {
  min-width: min(100%, 22rem);
}

.page-about .about-cta__title {
  margin: 0 0 0.4rem;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: 1.125rem;
  color: var(--sand);
}

.page-about .about-cta__sub {
  margin: 0;
  max-width: 52ch;
  font-size: 0.875rem;
  line-height: 1.75;
  color: var(--mist);
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

/* ---------- 悬停层次变化 ---------- */
@media (hover: hover) and (pointer: fine) {
  .page-about .about-tl__item:hover .about-tl__dot,
  .page-about .about-tl__item:focus-visible .about-tl__dot {
    background: var(--cyan);
    box-shadow: 0 0 0 5px rgba(43, 231, 214, 0.18), 0 0 16px rgba(43, 231, 214, 0.55);
  }

  .page-about .about-tl__item:hover .about-tl__text,
  .page-about .about-tl__item:focus-visible .about-tl__text {
    color: rgba(245, 241, 232, 0.95);
  }

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

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .about-cadence__cols {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

@media (min-width: 900px) {
  .page-about .about-intro__grid {
    grid-template-columns: minmax(0, 7fr) minmax(250px, 3fr);
    align-items: start;
  }

  .page-about .about-sec__grid {
    grid-template-columns: minmax(180px, 2fr) minmax(0, 8fr);
    gap: clamp(1.5rem, 4vw, 3.5rem);
  }

  .page-about .about-sec__head {
    position: sticky;
    top: calc(var(--bar-h) + 1.5rem);
  }

  .page-about .about-tl-wrap {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    align-items: start;
  }

  .page-about .about-tl-figure {
    position: sticky;
    top: calc(var(--bar-h) + 1.5rem);
  }

  .page-about .about-team-layout {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    align-items: start;
  }

  .page-about .about-team-figure {
    position: sticky;
    top: calc(var(--bar-h) + 1.5rem);
  }

  .page-about .about-local {
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    align-items: center;
  }
}

@media (min-width: 1000px) {
  .page-about .about-cadence__cols {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (max-width: 400px) {
  .page-about .about-tl__item {
    grid-template-columns: 0.9rem 3rem minmax(0, 1fr);
    column-gap: 0.5rem;
  }

  .page-about .about-tl::before {
    left: 4px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-tl__dot,
  .page-about .about-tl__text,
  .page-about .about-tl__title,
  .page-about .about-team__item,
  .page-about .about-index__link {
    transition: none;
  }

  .page-about .about-team__item:hover {
    transform: none;
  }
}