.page-about {
  background: var(--ink);
  color: var(--fog);
  padding-top: var(--header-space);
  overflow-x: clip;
  font-family: var(--font-body);
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  padding: clamp(36px, 6vw, 78px) 0 clamp(34px, 5vw, 62px);
  border-bottom: 1px solid var(--line);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -18%;
  right: -8%;
  width: min(54%, 640px);
  height: 136%;
  background: linear-gradient(155deg, rgba(255, 107, 26, 0.22), rgba(43, 227, 198, 0.07) 56%, transparent 80%);
  transform: rotate(-10deg);
  z-index: -1;
  pointer-events: none;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  inset: 0;
  background-image:
    linear-gradient(rgba(232, 237, 242, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(232, 237, 242, 0.035) 1px, transparent 1px);
  background-size: 64px 64px;
  -webkit-mask-image: radial-gradient(circle at 76% 24%, #000 0%, transparent 70%);
  mask-image: radial-gradient(circle at 76% 24%, #000 0%, transparent 70%);
  z-index: -2;
  pointer-events: none;
}

.page-about .about-kicker {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  margin: 20px 0 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--orange);
}

.page-about .about-kicker::before {
  content: "";
  width: 26px;
  height: 2px;
  background: var(--orange);
}

.page-about .about-title {
  margin: 0 0 20px;
  max-width: 16ch;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(32px, 6.2vw, 72px);
  line-height: 1.04;
  letter-spacing: -0.02em;
  color: var(--fog);
}

.page-about .about-lede {
  max-width: 64ch;
  margin: 0 0 34px;
  font-size: clamp(15px, 1.6vw, 18px);
  line-height: 1.8;
  color: var(--stone);
}

.page-about .about-hero-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  max-width: 760px;
  margin: 0;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .about-hero-stat {
  background: var(--ink-2);
  padding: 16px 18px;
}

.page-about .about-hero-stat dt {
  margin: 0 0 6px;
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--stone);
}

.page-about .about-hero-stat dd {
  margin: 0;
  font-size: 22px;
  font-weight: 700;
  line-height: 1.2;
  color: var(--cyan);
}

/* ---------- 主体骨架 ---------- */

.page-about .about-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 30px;
  padding: clamp(40px, 6vw, 88px) 0 clamp(24px, 3vw, 40px);
}

.page-about .about-rail {
  border-top: 1px solid var(--line);
  padding-top: 18px;
}

.page-about .about-rail-title {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--stone);
}

.page-about .about-rail-list {
  display: flex;
  gap: 8px;
  margin: 0;
  padding: 0 2px 6px;
  list-style: none;
  overflow-x: auto;
  scrollbar-width: none;
}

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

.page-about .about-rail-link {
  display: flex;
  align-items: center;
  gap: 9px;
  padding: 9px 14px;
  border: 1px solid var(--line);
  border-radius: 999px;
  background: var(--ink-2);
  color: var(--stone);
  font-size: 13px;
  line-height: 1.4;
  text-decoration: none;
  white-space: nowrap;
  transition: color 0.25s ease, border-color 0.25s ease, background-color 0.25s ease;
}

.page-about .about-rail-link:hover,
.page-about .about-rail-link:focus-visible {
  color: var(--fog);
  border-color: var(--orange);
  background: rgba(255, 107, 26, 0.08);
}

.page-about .about-rail-index {
  font-size: 11px;
  letter-spacing: 0.06em;
  color: var(--orange);
}

.page-about .about-flow {
  display: flex;
  flex-direction: column;
  gap: clamp(52px, 8vw, 108px);
  min-width: 0;
}

/* ---------- 章节 ---------- */

.page-about .about-block {
  position: relative;
  min-width: 0;
  scroll-margin-top: calc(var(--header-space) + 24px);
}

.page-about .about-block-head {
  display: flex;
  align-items: baseline;
  gap: 14px;
  margin-bottom: 22px;
  padding-bottom: 15px;
  border-bottom: 1px solid var(--line);
}

.page-about .about-block-index {
  flex: none;
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--orange);
}

.page-about .about-block-title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(23px, 3.3vw, 36px);
  line-height: 1.22;
  letter-spacing: -0.01em;
  color: var(--fog);
}

.page-about .about-block-lede {
  max-width: 68ch;
  margin: 0 0 30px;
  font-size: clamp(15px, 1.5vw, 17px);
  line-height: 1.85;
  color: var(--stone);
}

.page-about .about-split {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(24px, 4vw, 48px);
  align-items: start;
}

.page-about .about-prose p {
  margin: 0 0 18px;
  font-size: 16px;
  line-height: 1.85;
  color: var(--stone);
}

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

.page-about .about-prose--after {
  margin-top: 30px;
  max-width: 70ch;
}

.page-about .about-quote {
  margin: 26px 0 0;
  padding: 4px 0 4px 20px;
  border-left: 2px solid var(--cyan);
  font-family: var(--font-display);
  font-size: clamp(17px, 1.9vw, 21px);
  font-weight: 700;
  line-height: 1.65;
  color: var(--fog);
}

.page-about .about-note {
  margin: 28px 0 0;
  font-size: 13px;
  line-height: 1.8;
  color: var(--stone);
}

.page-about .about-note .text-link {
  color: var(--fog);
  text-decoration: none;
  border-bottom: 1px solid var(--orange);
  transition: border-color 0.25s ease, color 0.25s ease;
}

.page-about .about-note .text-link:hover,
.page-about .about-note .text-link:focus-visible {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

/* ---------- 图片 ---------- */

.page-about .about-figure {
  margin: 0;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: var(--ink-2);
  overflow: hidden;
}

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

.page-about .about-figure--wide img {
  aspect-ratio: 3 / 2;
}

.page-about .about-figure--photo {
  margin-bottom: 28px;
}

.page-about .about-figure--photo img {
  aspect-ratio: 5 / 3;
}

.page-about .about-split .about-figure--photo {
  margin-bottom: 0;
}

.page-about .about-figure .media-caption {
  padding: 12px 16px;
  border-top: 1px solid var(--line);
  font-size: 12px;
  line-height: 1.65;
  color: var(--stone);
}

/* ---------- 校验流程图 ---------- */

.page-about .about-flow-figure {
  margin: 0;
  padding: clamp(18px, 3vw, 30px);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background:
    linear-gradient(140deg, rgba(18, 26, 43, 0.96), rgba(11, 14, 17, 0.92));
}

.page-about .about-flow-svg {
  display: block;
  width: 100%;
  height: auto;
}

.page-about .about-flow-svg .flow-box {
  fill: rgba(11, 14, 17, 0.85);
  stroke: var(--line);
  stroke-width: 1.5;
  transition: stroke 0.3s ease, fill 0.3s ease;
}

.page-about .about-flow-svg .flow-label {
  fill: var(--fog);
  font-family: var(--font-mono);
  font-size: 15px;
  font-weight: 600;
  text-anchor: middle;
  transition: fill 0.3s ease;
}

.page-about .about-flow-svg .flow-sub {
  fill: var(--stone);
  font-family: var(--font-body);
  font-size: 12px;
  text-anchor: middle;
  transition: fill 0.3s ease;
}

.page-about .about-flow-svg .flow-link {
  fill: none;
  stroke: var(--line);
  stroke-width: 1.5;
  stroke-dasharray: 5 5;
  transition: stroke 0.3s ease;
}

.page-about .about-flow-svg .flow-node {
  outline: none;
  cursor: default;
}

.page-about .about-flow-svg .flow-node:hover .flow-box,
.page-about .about-flow-svg .flow-node:focus-visible .flow-box {
  fill: rgba(43, 227, 198, 0.1);
  stroke: var(--cyan);
}

.page-about .about-flow-svg .flow-node:hover .flow-label,
.page-about .about-flow-svg .flow-node:focus-visible .flow-label {
  fill: var(--cyan);
}

.page-about .about-flow-svg .flow-node:hover .flow-sub,
.page-about .about-flow-svg .flow-node:focus-visible .flow-sub {
  fill: var(--fog);
}

.page-about .about-flow-figure .media-caption {
  margin-top: 16px;
  padding-top: 14px;
  border-top: 1px solid var(--line);
  font-size: 12px;
  line-height: 1.65;
  color: var(--stone);
}

/* ---------- 版本档位 ---------- */

.page-about .about-tier-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 16px;
}

.page-about .about-tier {
  display: flex;
  flex-direction: column;
  gap: 12px;
  padding: 22px 20px 24px;
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background: linear-gradient(180deg, rgba(18, 26, 43, 0.94), rgba(11, 14, 17, 0.92));
  transition: border-color 0.3s ease;
}

.page-about .about-tier--1 { border-top: 2px solid rgba(255, 107, 26, 0.32); }
.page-about .about-tier--2 { border-top: 2px solid rgba(255, 107, 26, 0.55); }
.page-about .about-tier--3 { border-top: 2px solid rgba(255, 107, 26, 0.8); }
.page-about .about-tier--4 { border-top: 2px solid var(--orange); }

.page-about .about-tier:hover {
  border-color: rgba(43, 227, 198, 0.5);
}

.page-about .about-tier--4:hover {
  border-color: var(--orange);
}

.page-about .about-tier-tag {
  align-self: flex-start;
  padding: 4px 10px;
  border-radius: 999px;
  background: rgba(255, 107, 26, 0.12);
  color: var(--orange);
  font-size: 11px;
  letter-spacing: 0.14em;
}

.page-about .about-tier-title {
  margin: 0;
  font-size: 18px;
  font-weight: 700;
  line-height: 1.35;
  color: var(--fog);
}

.page-about .about-tier-desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--stone);
}

.page-about .about-tier-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin: auto 0 0;
  padding: 14px 0 0;
  border-top: 1px solid var(--line);
  list-style: none;
}

.page-about .about-tier-list li {
  position: relative;
  padding-left: 16px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--stone);
}

.page-about .about-tier-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 8px;
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--cyan);
}

/* ---------- 团队 ---------- */

.page-about .about-facts {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin-top: 30px;
  background: var(--line);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  overflow: hidden;
}

.page-about .about-fact {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 16px 18px;
  background: var(--ink-2);
}

.page-about .about-fact-value {
  font-size: 20px;
  font-weight: 700;
  line-height: 1.2;
  color: var(--cyan);
}

.page-about .about-fact-label {
  font-size: 12px;
  line-height: 1.55;
  color: var(--stone);
}

/* ---------- 年份时间线 ---------- */

.page-about .about-years {
  margin: 0;
  padding: 0 0 0 4px;
  list-style: none;
}

.page-about .about-year {
  position: relative;
  padding: 0 0 34px 28px;
  border-left: 1px solid var(--line);
}

.page-about .about-year:last-child {
  padding-bottom: 0;
  border-left-color: transparent;
}

.page-about .about-year-dot {
  position: absolute;
  left: -5px;
  top: 6px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--orange);
  box-shadow: 0 0 0 4px rgba(255, 107, 26, 0.14);
}

.page-about .about-year-dot--cyan {
  background: var(--cyan);
  box-shadow: 0 0 0 4px rgba(43, 227, 198, 0.14);
}

.page-about .about-year-label {
  margin: 0 0 8px;
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--orange);
}

.page-about .about-year-label--cyan {
  color: var(--cyan);
}

.page-about .about-year-title {
  margin: 0 0 6px;
  font-size: 17px;
  font-weight: 700;
  line-height: 1.4;
  color: var(--fog);
}

.page-about .about-year-body p {
  max-width: 68ch;
  margin: 0;
  font-size: 14px;
  line-height: 1.78;
  color: var(--stone);
}

.page-about .about-year--gold .about-year-dot {
  background: var(--gold);
  box-shadow: 0 0 0 4px rgba(242, 193, 78, 0.16);
}

.page-about .about-year--gold .about-year-label {
  color: var(--gold);
}

/* ---------- 收尾 ---------- */

.page-about .about-cta {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 22px;
  align-items: center;
  margin-bottom: clamp(48px, 7vw, 92px);
  padding: clamp(26px, 4vw, 46px);
  border: 1px solid var(--line);
  border-radius: var(--radius);
  background:
    linear-gradient(120deg, rgba(255, 107, 26, 0.16), rgba(43, 227, 198, 0.08) 62%, transparent 88%),
    var(--ink-2);
}

.page-about .about-cta-title {
  margin: 0 0 12px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(21px, 2.8vw, 30px);
  line-height: 1.3;
  color: var(--fog);
}

.page-about .about-cta-text p {
  max-width: 62ch;
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--stone);
}

.page-about .about-cta-text .text-link {
  color: var(--fog);
  text-decoration: none;
  border-bottom: 1px solid var(--orange);
  transition: border-color 0.25s ease, color 0.25s ease;
}

.page-about .about-cta-text .text-link:hover,
.page-about .about-cta-text .text-link:focus-visible {
  color: var(--cyan);
  border-bottom-color: var(--cyan);
}

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

/* ---------- 响应式 ---------- */

@media (min-width: 640px) {
  .page-about .about-hero-stats {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

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

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

@media (min-width: 780px) {
  .page-about .about-split {
    grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
  }

  .page-about .about-split--flip {
    grid-template-columns: minmax(0, 0.95fr) minmax(0, 1.05fr);
  }

  .page-about .about-split--flip > .about-prose {
    order: 2;
  }

  .page-about .about-split--flip > .about-figure {
    order: 1;
  }

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

  .page-about .about-cta-actions {
    flex-wrap: nowrap;
  }
}

@media (min-width: 960px) {
  .page-about .about-shell {
    grid-template-columns: 176px minmax(0, 1fr);
    gap: clamp(36px, 5vw, 76px);
    align-items: start;
  }

  .page-about .about-rail {
    position: sticky;
    top: calc(var(--header-space) + 24px);
  }

  .page-about .about-rail-list {
    flex-direction: column;
    gap: 2px;
    padding: 0;
    overflow: visible;
  }

  .page-about .about-rail-link {
    padding: 10px 0 10px 14px;
    border: 0;
    border-left: 2px solid var(--line);
    border-radius: 0;
    background: transparent;
    white-space: normal;
  }

  .page-about .about-rail-link:hover,
  .page-about .about-rail-link:focus-visible {
    border-left-color: var(--cyan);
    background: rgba(43, 227, 198, 0.05);
  }
}

@media (min-width: 1120px) {
  .page-about .about-tier-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-rail-link,
  .page-about .about-tier,
  .page-about .about-flow-svg .flow-box,
  .page-about .about-flow-svg .flow-label,
  .page-about .about-flow-svg .flow-sub,
  .page-about .about-flow-svg .flow-link {
    transition: none;
  }
}