.page-about {
  --pa-rule: rgba(58, 43, 92, 0.7);
  --pa-rail: 24px;
  --pa-node: 13px;
}

/* ---------- 首屏 ---------- */
.page-about .pa-hero {
  position: relative;
  padding: 34px 0 52px;
  background:
    radial-gradient(130% 96% at 94% -18%, rgba(198, 75, 255, 0.20), transparent 62%),
    linear-gradient(180deg, var(--ink-2) 0%, var(--ink) 100%);
  border-bottom: 1px solid var(--edge-soft);
  overflow: hidden;
}

.page-about .pa-hero::after {
  content: "";
  position: absolute;
  right: -90px;
  top: -70px;
  width: 320px;
  height: 320px;
  background: conic-gradient(from 205deg, rgba(76, 255, 176, 0.16), rgba(43, 231, 245, 0.10), transparent 64%);
  clip-path: var(--cut);
  pointer-events: none;
}

.page-about .pa-hero::before {
  content: "";
  position: absolute;
  right: 0;
  bottom: 0;
  width: 44%;
  height: 1px;
  background: linear-gradient(90deg, transparent, var(--edge));
  transform: rotate(-6deg);
  transform-origin: right bottom;
  pointer-events: none;
}

.page-about .pa-hero .arc-shell {
  position: relative;
  z-index: 1;
}

.page-about .pa-hero__title {
  margin: 12px 0 0;
  font-size: clamp(38px, 9vw, 76px);
  line-height: 1.02;
  font-weight: 900;
  letter-spacing: -0.02em;
  color: var(--paper);
}

.page-about .pa-hero__lead {
  margin: 18px 0 0;
  max-width: 60ch;
  font-size: var(--fs-1);
  line-height: 1.8;
  color: var(--mute);
}

.page-about .pa-hero__meta {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 10px;
  margin: 30px 0 0;
  padding: 0;
  list-style: none;
}

.page-about .pa-hero__meta li {
  position: relative;
  padding: 12px 14px 13px 16px;
  background: rgba(30, 18, 53, 0.72);
  clip-path: var(--cut-sm);
}

.page-about .pa-hero__meta li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  bottom: 10px;
  width: 2px;
  background: var(--cyan);
  opacity: 0.85;
}

.page-about .pa-hero__k {
  display: block;
  font-size: 13px;
  line-height: 1.4;
  color: var(--mute-dim);
  letter-spacing: 0.04em;
}

.page-about .pa-hero__v {
  display: block;
  margin-top: 4px;
  font-size: var(--fs-2);
  font-weight: 700;
  line-height: 1.2;
  color: var(--paper);
}

.page-about .pa-hero__jump {
  margin: 26px 0 0;
  font-size: 15px;
}

.page-about .pa-jump {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-family: var(--font-mono);
  color: var(--cyan);
  text-decoration: none;
  padding-bottom: 2px;
  border-bottom: 1px solid rgba(43, 231, 245, 0.4);
  transition: color 160ms ease, border-color 160ms ease;
}

.page-about .pa-jump:hover {
  color: var(--green);
  border-bottom-color: var(--green);
}

/* ---------- 通用章节 ---------- */
.page-about .pa-sec {
  padding: 48px 0;
  border-bottom: 1px solid var(--edge-soft);
}

.page-about .pa-sec--region {
  border-bottom: 0;
  padding-bottom: 64px;
}

.page-about .pa-sec__head {
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px 16px;
  margin-bottom: 16px;
}

.page-about .pa-sec__num {
  font-family: var(--font-mono);
  font-size: 14px;
  letter-spacing: 0.1em;
  color: var(--mango);
}

.page-about .pa-sec__title {
  margin: 0;
  font-size: clamp(25px, 4.6vw, 39px);
  line-height: 1.16;
  font-weight: 900;
  color: var(--paper);
  letter-spacing: -0.01em;
}

.page-about .pa-sec__lead {
  margin: 0 0 26px;
  max-width: 62ch;
  font-size: var(--fs-1);
  line-height: 1.8;
  color: var(--mute);
}

/* ---------- 时间线 ---------- */
.page-about .pa-tl__banner {
  margin: 0 0 32px;
  aspect-ratio: auto;
  height: 190px;
  overflow: hidden;
  clip-path: var(--cut);
  clip-path: var(--cut);
}

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

.page-about .pa-tl {
  position: relative;
  margin: 0;
  padding: 0 0 0 var(--pa-rail);
  list-style: none;
}

.page-about .pa-tl::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 6px;
  bottom: 14px;
  width: 1px;
  background: linear-gradient(180deg, var(--magenta) 0%, rgba(198, 75, 255, 0.45) 55%, rgba(198, 75, 255, 0.1) 100%);
}

.page-about .pa-tl__item {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 6px;
  padding-bottom: 22px;
}

.page-about .pa-tl__item::before {
  content: "";
  position: absolute;
  left: calc(-1 * var(--pa-rail));
  top: 6px;
  width: var(--pa-node);
  height: var(--pa-node);
  background: var(--ink);
  border: 1px solid var(--magenta);
  clip-path: var(--cut-xs);
}

.page-about .pa-tl__item.is-done::before {
  background: var(--green);
  border-color: var(--green);
}

.page-about .pa-tl__item.is-current::before {
  background: var(--cyan);
  border-color: var(--cyan);
  box-shadow: 0 0 0 3px rgba(43, 231, 245, 0.16);
}

.page-about .pa-tl__year {
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.04em;
  color: var(--mango);
}

.page-about .pa-tl__fold summary {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 6px 12px;
  padding: 3px 0;
  cursor: pointer;
  list-style: none;
  color: var(--paper);
}

.page-about .pa-tl__fold summary::-webkit-details-marker {
  display: none;
}

.page-about .pa-tl__fold summary::after {
  content: "+";
  margin-left: auto;
  font-family: var(--font-mono);
  font-size: 18px;
  line-height: 1;
  color: var(--cyan);
}

.page-about .pa-tl__fold[open] summary::after {
  content: "−";
}

.page-about .pa-tl__name {
  font-size: clamp(19px, 2.8vw, 25px);
  font-weight: 800;
  line-height: 1.32;
}

.page-about .pa-tl__tag {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--mute-dim);
  padding: 2px 7px;
  border: 1px solid var(--edge);
  clip-path: var(--cut-xs);
}

.page-about .pa-tl__body {
  margin: 10px 0 0;
  max-width: 62ch;
  font-size: var(--fs-1);
  line-height: 1.8;
  color: var(--mute);
}

/* ---------- 出题工序 ---------- */
.page-about .pa-steps {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 14px;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .pa-steps__item {
  position: relative;
  padding: 20px 18px 24px;
  background: var(--ink-2);
  clip-path: var(--cut);
}

.page-about .pa-steps__item::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--green), var(--cyan));
}

.page-about .pa-steps__idx {
  display: inline-block;
  font-size: 13px;
  font-weight: 700;
  letter-spacing: 0.14em;
  color: var(--cyan);
}

.page-about .pa-steps__t {
  margin: 10px 0 0;
  font-size: var(--fs-2);
  font-weight: 800;
  line-height: 1.4;
  color: var(--paper);
}

.page-about .pa-steps__d {
  margin: 10px 0 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--mute);
}

/* ---------- 团队矩阵 ---------- */
.page-about .pa-crew__banner {
  margin: 0 0 20px;
  aspect-ratio: auto;
  height: 170px;
  overflow: hidden;
  clip-path: var(--cut);
}

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

.page-about .pa-crew__matrix {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 10px;
}

.page-about .pa-crew__cell {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: 8px;
  padding: 18px 16px 22px;
  background: var(--ink-2);
  clip-path: var(--cut-sm);
  transition: transform 180ms ease, background-color 180ms ease;
}

.page-about .pa-crew__cell::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 2px;
  background: var(--edge);
  transition: background 180ms ease;
}

.page-about .pa-crew__cell:hover,
.page-about .pa-crew__cell:focus-within {
  transform: translateY(-2px);
  background: var(--ink-3);
}

.page-about .pa-crew__cell:hover::after,
.page-about .pa-crew__cell:focus-within::after {
  background: linear-gradient(90deg, var(--green), var(--cyan));
}

.page-about .pa-crew__role {
  margin: 0;
  font-size: var(--fs-2);
  font-weight: 800;
  line-height: 1.3;
  color: var(--paper);
}

.page-about .pa-crew__num {
  margin: 0;
  font-size: 14px;
  letter-spacing: 0.06em;
  color: var(--mango);
}

.page-about .pa-crew__out {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--mute-dim);
  transition: color 180ms ease;
}

.page-about .pa-crew__cell:hover .pa-crew__out,
.page-about .pa-crew__cell:focus-within .pa-crew__out {
  color: var(--paper);
}

/* ---------- 补题节拍 ---------- */
.page-about .pa-cadence {
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0;
  border-top: 1px solid var(--edge-soft);
}

.page-about .pa-cadence__row {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 8px;
  padding: 18px 0 20px;
  border-bottom: 1px solid var(--edge-soft);
}

.page-about .pa-cadence__k {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--mute-dim);
}

.page-about .pa-cadence__v {
  margin: 0;
}

.page-about .pa-cadence__big {
  display: block;
  font-size: var(--fs-3);
  font-weight: 700;
  line-height: 1.25;
  color: var(--paper);
}

.page-about .pa-cadence__d {
  display: block;
  margin-top: 8px;
  max-width: 58ch;
  font-size: 15px;
  line-height: 1.78;
  color: var(--mute);
}

.page-about .pa-cadence__more {
  margin: 24px 0 0;
  font-size: 15px;
  line-height: 1.8;
  color: var(--mute);
}

.page-about .pa-cadence__more a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(43, 231, 245, 0.4);
}

.page-about .pa-cadence__more a:hover {
  color: var(--green);
  border-bottom-color: var(--green);
}

/* ---------- 运营与备案 ---------- */
.page-about .pa-region {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 26px;
}

.page-about .pa-region__media {
  margin: 0;
  aspect-ratio: 4 / 3;
  overflow: hidden;
  clip-path: var(--cut);
}

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

.page-about .pa-region__dl {
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--edge-soft);
}

.page-about .pa-region__dl > div {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 4px;
  padding: 13px 0 14px;
  border-bottom: 1px solid var(--edge-soft);
}

.page-about .pa-region__dl dt {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--mute-dim);
}

.page-about .pa-region__dl dd {
  margin: 0;
  font-size: var(--fs-1);
  line-height: 1.7;
  color: var(--paper);
  word-break: break-word;
}

.page-about .pa-region__note {
  margin: 20px 0 0;
  max-width: 62ch;
  font-size: 15px;
  line-height: 1.8;
  color: var(--mute);
}

.page-about .pa-region__note a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(43, 231, 245, 0.4);
}

.page-about .pa-region__note a:hover {
  color: var(--green);
  border-bottom-color: var(--green);
}

/* ---------- 响应式 ---------- */
@media (min-width: 640px) {
  .page-about .pa-hero {
    padding: 46px 0 60px;
  }

  .page-about .pa-hero__meta {
    grid-template-columns: repeat(4, minmax(0, 1fr));
    gap: 14px;
  }

  .page-about .pa-tl__banner {
    height: 240px;
  }

  .page-about .pa-crew__banner {
    height: 210px;
  }

  .page-about .pa-cadence__row {
    grid-template-columns: 130px minmax(0, 1fr);
    gap: 6px 26px;
    align-items: start;
  }

  .page-about .pa-cadence__k {
    padding-top: 5px;
  }

  .page-about .pa-region__dl > div {
    grid-template-columns: 130px minmax(0, 1fr);
    gap: 8px 26px;
    align-items: baseline;
  }
}

@media (min-width: 820px) {
  .page-about .pa-tl__item {
    grid-template-columns: 108px minmax(0, 1fr);
    gap: 0 30px;
    padding-bottom: 18px;
  }

  .page-about .pa-tl__year {
    padding-top: 4px;
    text-align: left;
  }

  .page-about .pa-steps {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 18px;
  }

  .page-about .pa-region {
    grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.15fr);
    gap: 46px;
    align-items: start;
  }
}

@media (min-width: 900px) {
  .page-about .pa-crew__matrix {
    grid-template-columns: repeat(12, minmax(0, 1fr));
  }

  .page-about .pa-crew__cell--a {
    grid-column: span 5;
  }

  .page-about .pa-crew__cell--b {
    grid-column: span 3;
  }

  .page-about .pa-crew__cell--c {
    grid-column: span 2;
  }

  .page-about .pa-crew__cell--d {
    grid-column: span 2;
  }
}

@media (min-width: 1024px) {
  .page-about .pa-sec {
    padding: 62px 0;
  }

  .page-about .pa-tl__banner {
    height: 290px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .pa-crew__cell,
  .page-about .pa-crew__cell::after,
  .page-about .pa-crew__out,
  .page-about .pa-jump {
    transition: none;
  }

  .page-about .pa-crew__cell:hover,
  .page-about .pa-crew__cell:focus-within {
    transform: none;
  }
}