.page-about {
  --about-rail: 104px;
}

.page-about .breadcrumbs {
  padding-top: clamp(16px, 3vw, 28px);
}

.page-about .crumbs {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin: 0;
  padding: 0;
  list-style: none;
  font-family: var(--f-mono);
  font-size: 11px;
  letter-spacing: .08em;
  color: var(--c-mist);
}

.page-about .crumbs li {
  display: flex;
  align-items: center;
  gap: 8px;
}

.page-about .crumbs li + li::before {
  content: "/";
  color: var(--c-steel);
}

.page-about .crumbs a {
  color: var(--c-mist);
  text-decoration: none;
  transition: color .2s var(--ease);
}

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

.page-about .crumbs [aria-current="page"] {
  color: var(--c-white);
}

/* 首屏 */
.page-about .about-hero {
  position: relative;
  overflow: hidden;
  padding: clamp(28px, 5vw, 56px) 0 clamp(16px, 3vw, 32px);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: -30% -12% 0;
  background:
    radial-gradient(58% 68% at 14% 12%, rgba(53, 242, 208, .15), transparent 66%),
    radial-gradient(50% 62% at 88% 0%, rgba(124, 92, 255, .16), transparent 68%);
  pointer-events: none;
}

.page-about .about-hero__inner {
  position: relative;
  display: grid;
  gap: clamp(28px, 5vw, 52px);
  align-items: start;
}

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

.page-about .about-hero h1 {
  margin: 16px 0 20px;
  max-width: 18ch;
}

.page-about .about-hero__note {
  margin: 18px 0 0;
  padding-left: 14px;
  border-left: 2px solid rgba(255, 107, 74, .75);
  color: var(--c-mist);
  font-size: 15px;
  line-height: 1.7;
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: clamp(22px, 4vw, 32px);
}

.page-about .about-facts {
  display: grid;
  gap: 10px;
  margin: 0;
  padding: 0;
  list-style: none;
  min-width: 0;
}

.page-about .about-fact {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  gap: 6px 16px;
  align-items: baseline;
  padding: 16px 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: linear-gradient(145deg, rgba(11, 34, 57, .92), rgba(6, 20, 35, .66));
}

.page-about .about-fact__num {
  font-family: var(--f-mono);
  font-size: clamp(26px, 3.4vw, 34px);
  font-weight: 700;
  line-height: 1;
  color: var(--c-cyan);
  font-variant-numeric: tabular-nums;
}

.page-about .about-fact__num em {
  font-style: normal;
  font-size: .5em;
  margin-left: 2px;
  color: var(--c-signal);
}

.page-about .about-fact__label {
  font-size: 14px;
  line-height: 1.65;
  color: var(--c-mist);
}

/* 章节骨架 */
.page-about .chapter {
  position: relative;
  padding-block: clamp(44px, 6vw, 88px);
}

.page-about .chapter__grid {
  display: grid;
  gap: clamp(14px, 3vw, 24px);
}

.page-about .chapter__rail {
  display: flex;
  align-items: center;
  gap: 14px;
}

.page-about .chapter__num {
  font-family: var(--f-mono);
  font-size: clamp(22px, 3vw, 28px);
  font-weight: 700;
  letter-spacing: .04em;
  color: var(--c-cyan);
  font-variant-numeric: tabular-nums;
}

.page-about .chapter__num::after {
  content: "";
  display: inline-block;
  width: clamp(28px, 8vw, 70px);
  height: 2px;
  margin-left: 14px;
  vertical-align: middle;
  background: linear-gradient(90deg, var(--c-cyan), transparent);
}

.page-about .chapter__label {
  font-family: var(--f-mono);
  font-size: 11px;
  letter-spacing: .18em;
  color: var(--c-mist);
}

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

.page-about .chapter__body h2 {
  margin: 0 0 18px;
  max-width: 22ch;
}

.page-about .chapter__body .prose {
  max-width: 66ch;
  margin: 0 0 18px;
  color: var(--c-mist);
}

.page-about .chapter__body .prose a {
  color: var(--c-signal);
  text-decoration: underline;
  text-decoration-color: rgba(25, 200, 230, .45);
  text-underline-offset: 3px;
}

.page-about .chapter__body .prose a:hover {
  color: var(--c-cyan);
}

.page-about .thesis {
  margin: 26px 0 0;
  padding: 18px 22px;
  border-left: 3px solid var(--c-coral);
  border-radius: 0 var(--radius-md) var(--radius-md) 0;
  background: linear-gradient(90deg, rgba(255, 107, 74, .12), rgba(11, 34, 57, .45) 60%, transparent);
  color: var(--c-white);
  font-size: 16px;
  font-weight: 600;
  line-height: 1.7;
  max-width: 62ch;
}

/* 图片 */
.page-about .about-figure {
  margin: 28px 0 0;
}

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

/* 评测维度 */
.page-about .principle-grid {
  display: grid;
  gap: 12px;
  margin-top: 26px;
}

.page-about .principle {
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: linear-gradient(160deg, rgba(11, 34, 57, .88), rgba(6, 20, 35, .62));
  transition: border-color .22s var(--ease), transform .22s var(--ease);
}

.page-about .principle:hover {
  border-color: rgba(53, 242, 208, .5);
  transform: translateY(-2px);
}

.page-about .principle[open] {
  border-color: rgba(53, 242, 208, .62);
}

.page-about .principle > summary {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px;
  padding: 16px 18px;
  list-style: none;
  cursor: pointer;
  font-size: 16px;
  font-weight: 700;
  color: var(--c-white);
}

.page-about .principle > summary::-webkit-details-marker {
  display: none;
}

.page-about .principle > summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--f-mono);
  font-size: 16px;
  color: var(--c-cyan);
}

.page-about .principle[open] > summary::after {
  content: "–";
}

.page-about .principle__no {
  font-family: var(--f-mono);
  font-size: 12px;
  color: var(--c-signal);
}

.page-about .principle > summary em {
  flex: 1 1 100%;
  font-style: normal;
  font-weight: 500;
  font-size: 13px;
  color: var(--c-mist);
}

.page-about .principle__body {
  margin: 0;
  padding: 0 18px 18px;
  font-size: 15px;
  line-height: 1.75;
  color: var(--c-mist);
}

/* 更新节奏 */
.page-about .cadence {
  margin-top: 26px;
  padding: 20px 22px;
  border: 1px solid rgba(15, 118, 110, .55);
  border-radius: var(--radius-md);
  background: linear-gradient(140deg, rgba(15, 118, 110, .18), rgba(6, 20, 35, .7));
}

.page-about .cadence__title {
  margin: 0 0 12px;
  font-family: var(--f-mono);
  font-size: 11px;
  letter-spacing: .2em;
  color: var(--c-cyan);
}

.page-about .cadence__list {
  margin: 0;
  padding-left: 18px;
  display: grid;
  gap: 8px;
  font-size: 15px;
  line-height: 1.7;
  color: var(--c-white);
}

.page-about .cadence__list li::marker {
  color: var(--c-signal);
}

/* 时间轴 */
.page-about .tl-track {
  display: flex;
  gap: 14px;
  margin: 24px 0 0;
  padding: 4px 4px 20px;
  list-style: none;
  overflow-x: auto;
  scroll-snap-type: x proximity;
  -webkit-overflow-scrolling: touch;
}

.page-about .tl-node {
  position: relative;
  flex: 0 0 min(300px, 78vw);
  scroll-snap-align: start;
  padding: 24px 20px 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: linear-gradient(170deg, rgba(11, 34, 57, .94), rgba(6, 20, 35, .76));
  transition: border-color .22s var(--ease);
}

.page-about .tl-node:hover {
  border-color: rgba(53, 242, 208, .5);
}

.page-about .tl-node::before {
  content: "";
  position: absolute;
  top: 0;
  left: 20px;
  right: 20px;
  height: 2px;
  border-radius: 2px;
  background: linear-gradient(90deg, var(--c-cyan), var(--c-signal) 55%, transparent);
}

.page-about .tl-node__phase {
  display: inline-block;
  font-family: var(--f-mono);
  font-size: 11px;
  letter-spacing: .14em;
  color: var(--c-cyan);
}

.page-about .tl-node h3 {
  margin: 10px 0 8px;
  font-size: clamp(18px, 2vw, 22px);
}

.page-about .tl-node p {
  margin: 0;
  font-size: 15px;
  line-height: 1.7;
  color: var(--c-mist);
}

/* 团队 */
.page-about .role-grid {
  display: grid;
  gap: 14px;
  margin-top: 26px;
}

.page-about .role {
  padding: 18px 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: linear-gradient(150deg, rgba(124, 92, 255, .14), rgba(11, 34, 57, .58));
}

.page-about .role__tag {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 5px 14px;
  border-radius: var(--radius-pill);
  border: 1px solid rgba(53, 242, 208, .38);
  font-family: var(--f-mono);
  font-size: 12px;
  letter-spacing: .08em;
  color: var(--c-cyan);
}

.page-about .role p {
  margin: 12px 0 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--c-mist);
}

/* 场景 */
.page-about .scene-list {
  margin: 24px 0 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--line);
}

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

.page-about .scene__name {
  font-family: var(--f-mono);
  font-size: 12px;
  letter-spacing: .12em;
  color: var(--c-cyan);
}

.page-about .scene__text {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--c-white);
  max-width: 62ch;
}

.page-about .scene__text a {
  color: var(--c-signal);
  text-decoration: underline;
  text-decoration-color: rgba(25, 200, 230, .45);
  text-underline-offset: 3px;
}

.page-about .scene__text a:hover {
  color: var(--c-cyan);
}

/* 生态 */
.page-about .eco {
  display: grid;
  gap: 14px;
  margin-top: 8px;
}

.page-about .eco__card {
  padding: 20px;
  border: 1px solid var(--line);
  border-radius: var(--radius-md);
  background: linear-gradient(155deg, rgba(11, 34, 57, .8), rgba(6, 20, 35, .55));
}

.page-about .eco__value {
  display: block;
  font-family: var(--f-mono);
  font-size: clamp(30px, 4.4vw, 42px);
  font-weight: 700;
  line-height: 1;
  color: var(--c-cyan);
  font-variant-numeric: tabular-nums;
}

.page-about .eco__label {
  display: block;
  margin-top: 12px;
  font-size: 14px;
  line-height: 1.65;
  color: var(--c-mist);
}

/* 收束 */
.page-about .about-cta {
  display: grid;
  gap: 20px;
  margin-bottom: clamp(48px, 7vw, 96px);
  padding: clamp(26px, 4vw, 44px);
  border: 1px solid rgba(53, 242, 208, .28);
  border-radius: var(--radius-lg);
  background:
    radial-gradient(110% 130% at 0% 0%, rgba(53, 242, 208, .16), transparent 62%),
    linear-gradient(140deg, rgba(11, 34, 57, .95), rgba(4, 16, 28, .92));
}

.page-about .about-cta h2 {
  margin: 0 0 12px;
  font-size: clamp(24px, 3.2vw, 34px);
}

.page-about .about-cta p {
  margin: 0;
  max-width: 58ch;
  font-size: 15px;
  line-height: 1.75;
  color: var(--c-mist);
}

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

@media (min-width: 720px) {
  .page-about .principle-grid,
  .page-about .role-grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

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

  .page-about .scene {
    grid-template-columns: 150px minmax(0, 1fr);
    gap: 24px;
    align-items: baseline;
  }
}

@media (min-width: 900px) {
  .page-about .chapter__grid {
    grid-template-columns: var(--about-rail) minmax(0, 1fr);
    column-gap: clamp(28px, 5vw, 64px);
  }

  .page-about .chapter__rail {
    position: sticky;
    top: 132px;
    align-self: start;
    flex-direction: column;
    align-items: flex-start;
    gap: 12px;
  }

  .page-about .chapter__num::after {
    display: none;
  }

  .page-about .chapter__label {
    writing-mode: vertical-rl;
    letter-spacing: .3em;
  }

  .page-about .chapter--narrow .chapter__body {
    max-width: 64ch;
  }

  .page-about .about-cta {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    gap: 32px;
  }
}

@media (min-width: 980px) {
  .page-about .about-hero__inner {
    grid-template-columns: minmax(0, 1.32fr) minmax(0, .78fr);
    gap: clamp(32px, 5vw, 64px);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about * {
    transition: none !important;
    animation: none !important;
  }
}