.page-about {
  --about-cut: 16px;
  --about-gap: clamp(64px, 9vw, 128px);
  background:
    radial-gradient(900px 520px at 88% -6%, rgba(53, 227, 201, .12), transparent 62%),
    radial-gradient(820px 520px at -12% 24%, rgba(255, 122, 44, .10), transparent 62%),
    var(--ink);
  color: var(--mist);
}

.page-about .about-crumbs {
  padding-top: clamp(20px, 4vw, 34px);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding: clamp(18px, 4vw, 40px) 0 clamp(56px, 8vw, 100px);
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(28px, 5vw, 52px);
}

.page-about .about-hero__eyebrow {
  margin: 0 0 clamp(16px, 3vw, 24px);
  color: var(--neon);
  letter-spacing: .2em;
}

.page-about h1 {
  margin: 0 0 clamp(18px, 3vw, 26px);
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(30px, 6.6vw, 54px);
  line-height: 1.18;
  letter-spacing: .03em;
  color: var(--mist);
}

.page-about .about-hero__intro {
  margin: 0;
  max-width: 40em;
  font-size: clamp(17px, 2.4vw, 20px);
  line-height: 1.85;
  color: rgba(243, 245, 251, .86);
}

.page-about .about-hero__fact {
  padding: clamp(24px, 4vw, 34px);
  background: linear-gradient(160deg, var(--ink-2) 0%, var(--ink-3) 160%);
  box-shadow: inset 0 0 0 1px var(--line);
  clip-path: polygon(
    var(--about-cut) 0,
    100% 0,
    100% calc(100% - var(--about-cut)),
    calc(100% - var(--about-cut)) 100%,
    0 100%,
    0 var(--about-cut)
  );
}

.page-about .fact-list {
  margin: 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .fact {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--line);
}

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

.page-about .fact dt {
  font-size: 14px;
  letter-spacing: .04em;
  color: var(--slate);
}

.page-about .fact dd {
  margin: 0;
  font-family: var(--font-mono);
  font-size: 22px;
  font-weight: 500;
  color: var(--orange);
}

.page-about .fact dd span {
  margin-left: 6px;
  font-size: 13px;
  font-weight: 500;
  color: var(--slate);
}

/* ---------- 章节通用 ---------- */
.page-about .about-section {
  padding: clamp(46px, 7vw, 96px) 0;
}

.page-about .mono-index {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: .22em;
  text-transform: uppercase;
  color: var(--neon);
}

.page-about .chapter-head {
  margin-bottom: clamp(20px, 3vw, 32px);
}

.page-about .chapter-head h2,
.page-about .about-close__body h2 {
  margin: 0 0 clamp(16px, 3vw, 22px);
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(23px, 3.8vw, 36px);
  line-height: 1.28;
  letter-spacing: .035em;
  color: var(--mist);
}

.page-about .about-text {
  margin: 0;
  max-width: 42em;
  font-size: 17px;
  line-height: 1.9;
  color: rgba(243, 245, 251, .8);
}

.page-about .about-text + .about-text {
  margin-top: 16px;
}

/* ---------- 沿革时间柱 ---------- */
.page-about .timeline {
  display: grid;
  gap: clamp(24px, 4vw, 44px);
}

.page-about .timeline__rail {
  display: none;
}

.page-about .stage-list {
  list-style: none;
  margin: clamp(26px, 4vw, 44px) 0 0;
  padding: 0;
  display: grid;
  gap: clamp(20px, 3.2vw, 34px);
}

.page-about .stage {
  padding: clamp(22px, 3.4vw, 32px) clamp(20px, 3vw, 32px);
  background: linear-gradient(150deg, rgba(22, 36, 74, .94), rgba(15, 26, 54, .62));
  box-shadow: inset 0 0 0 1px var(--line);
  clip-path: polygon(
    var(--about-cut) 0,
    100% 0,
    100% calc(100% - var(--about-cut)),
    calc(100% - var(--about-cut)) 100%,
    0 100%,
    0 var(--about-cut)
  );
  transition: box-shadow var(--dur) var(--ease), background var(--dur) var(--ease);
}

.page-about .stage:hover {
  box-shadow: inset 0 0 0 1px var(--neon);
  background: linear-gradient(150deg, rgba(43, 74, 150, .55), rgba(15, 26, 54, .7));
}

.page-about .stage__no {
  margin-bottom: 10px;
  color: var(--orange);
  letter-spacing: .16em;
}

.page-about .stage h3 {
  margin: 0 0 12px;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(19px, 2.6vw, 23px);
  line-height: 1.4;
  letter-spacing: .03em;
  color: var(--mist);
}

/* ---------- 配图 ---------- */
.page-about .about-figure {
  margin: clamp(28px, 4vw, 46px) 0 0;
}

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

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

/* ---------- 团队分工 ---------- */
.page-about .about-split {
  display: grid;
  gap: clamp(26px, 4.5vw, 52px);
  align-items: center;
}

/* ---------- 更新节奏 ---------- */
.page-about .rhythm-grid {
  display: grid;
  gap: clamp(22px, 3.4vw, 40px);
}

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

.page-about .flow li {
  position: relative;
  padding: 15px 18px 15px 58px;
  background: var(--ink-2);
  box-shadow: inset 0 0 0 1px var(--line);
  font-size: 15px;
  line-height: 1.7;
  color: rgba(243, 245, 251, .84);
  clip-path: polygon(
    12px 0,
    100% 0,
    100% calc(100% - 12px),
    calc(100% - 12px) 100%,
    0 100%,
    0 12px
  );
}

.page-about .flow li::before {
  counter-increment: flow;
  content: counter(flow, decimal-leading-zero);
  position: absolute;
  left: 18px;
  top: 15px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: .12em;
  color: var(--orange);
}

/* ---------- 回访带 ---------- */
.page-about .visit-band {
  padding: clamp(26px, 4vw, 46px);
  background: linear-gradient(115deg, rgba(255, 122, 44, .16) 0%, rgba(53, 227, 201, .07) 58%, transparent 100%);
  border-left: 3px solid var(--orange);
}

.page-about .visit-band .chapter-head {
  margin-bottom: clamp(16px, 2.4vw, 22px);
}

/* ---------- 做事方式 ---------- */
.page-about .creed-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: clamp(18px, 2.6vw, 26px);
}

.page-about .creed {
  position: relative;
  padding: clamp(22px, 3vw, 30px) clamp(20px, 3vw, 28px);
  background: linear-gradient(180deg, rgba(22, 36, 74, .9), rgba(15, 26, 54, .7));
  box-shadow: inset 0 0 0 1px var(--line);
  border-top: 2px solid var(--ink-3);
  transition: border-color var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}

.page-about .creed:hover {
  border-top-color: var(--neon);
  box-shadow: inset 0 0 0 1px var(--neon);
}

.page-about .creed__no {
  margin-bottom: 12px;
  font-size: 15px;
  color: var(--orange);
  letter-spacing: .18em;
}

.page-about .creed h3 {
  margin: 0 0 12px;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: clamp(18px, 2.4vw, 21px);
  letter-spacing: .03em;
  color: var(--mist);
}

/* ---------- 常来这里的人 ---------- */
.page-about .visitor-grid {
  display: grid;
  gap: clamp(20px, 3vw, 30px);
}

.page-about .visitor-card {
  padding: clamp(24px, 3.6vw, 38px);
  background: var(--ink-2);
  box-shadow: inset 0 0 0 1px var(--line);
  clip-path: polygon(
    var(--about-cut) 0,
    100% 0,
    100% calc(100% - var(--about-cut)),
    calc(100% - var(--about-cut)) 100%,
    0 100%,
    0 var(--about-cut)
  );
}

.page-about .visitor-card--lead {
  background: linear-gradient(150deg, var(--ink-3) 0%, var(--ink-2) 90%);
}

.page-about .visitor-card__big {
  margin: 0 0 16px;
  font-family: var(--font-mono);
  font-size: clamp(38px, 7vw, 58px);
  font-weight: 500;
  line-height: 1;
  color: var(--orange);
}

.page-about .visitor-card__big span {
  margin-left: 10px;
  font-family: var(--font-body);
  font-size: 15px;
  font-weight: 400;
  letter-spacing: .04em;
  color: var(--slate);
}

/* ---------- 收束 ---------- */
.page-about .about-close {
  position: relative;
  background: var(--deep);
}

.page-about .about-close__figure {
  margin: 0;
  position: relative;
}

.page-about .about-close__figure img {
  height: clamp(220px, 34vw, 420px);
}

.page-about .about-close__figure::after {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(180deg, var(--ink) 0%, rgba(7, 12, 28, .5) 48%, var(--deep) 100%);
}

.page-about .about-close__body {
  position: relative;
  padding-bottom: clamp(56px, 8vw, 104px);
}

.page-about .about-close__body .mono-index {
  color: var(--neon);
}

.page-about .about-links {
  list-style: none;
  margin: clamp(24px, 4vw, 36px) 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

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

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.45fr) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .about-split {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, .9fr);
  }

  .page-about .rhythm-grid {
    grid-template-columns: minmax(0, .85fr) minmax(0, 1.15fr);
    align-items: start;
  }

  .page-about .about-figure--right {
    width: min(74%, 660px);
    margin-left: auto;
  }

  .page-about .visitor-grid {
    grid-template-columns: minmax(0, 1.2fr) minmax(0, .8fr);
    align-items: start;
  }

  .page-about .visitor-card:not(.visitor-card--lead) {
    margin-top: 52px;
  }

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

@media (min-width: 1000px) {
  .page-about .timeline {
    grid-template-columns: 92px minmax(0, 1fr);
    gap: clamp(32px, 4vw, 56px);
  }

  .page-about .timeline__rail {
    display: block;
    position: sticky;
    top: 132px;
    align-self: start;
    height: min(58vh, 460px);
  }

  .page-about .timeline__line {
    position: absolute;
    left: 11px;
    top: 10px;
    bottom: 10px;
    width: 1px;
    background: linear-gradient(180deg, var(--neon) 0%, var(--line) 72%, transparent 100%);
  }

  .page-about .timeline__marks {
    list-style: none;
    margin: 0;
    padding: 0;
    height: 100%;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
  }

  .page-about .timeline__marks li {
    position: relative;
    padding-left: 34px;
    font-family: var(--font-mono);
    font-size: 13px;
    letter-spacing: .16em;
    color: var(--slate);
  }

  .page-about .timeline__marks li::before {
    content: "";
    position: absolute;
    left: 6px;
    top: 50%;
    width: 11px;
    height: 11px;
    background: var(--ink);
    border: 1px solid var(--line);
    transform: translateY(-50%) rotate(45deg);
  }

  .page-about .timeline__marks li:first-child::before {
    background: var(--neon);
    border-color: var(--neon);
  }

  .page-about .timeline__marks li:first-child {
    color: var(--neon);
  }
}