.page-about {
  --about-ink-soft: #cfd8e0;
  --about-line-soft: rgba(243, 246, 244, 0.08);
  background: var(--ink);
  color: var(--paper);
  font-family: var(--font-sans);
  overflow-x: hidden;
  display: block;
}

.page-about .about-crumb {
  padding-top: 28px;
}

.page-about .about-crumb .crumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  list-style: none;
  margin: 0;
  padding: 0;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.02em;
  color: var(--muted);
}

.page-about .about-crumb .crumb > li + li::before {
  content: "/";
  margin-right: 6px;
  color: var(--line);
}

.page-about .about-crumb .crumb a {
  color: var(--muted);
  text-decoration: none;
}

.page-about .about-crumb .crumb a:hover,
.page-about .about-crumb .crumb a:focus-visible {
  color: var(--spring);
}

.page-about .about-crumb .crumb li[aria-current="page"] {
  color: var(--paper);
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 36px;
  padding-top: 28px;
  padding-bottom: 56px;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: -20px;
  right: -18vw;
  width: 300px;
  height: 280px;
  background: linear-gradient(140deg, rgba(46, 212, 122, 0.24), rgba(91, 155, 255, 0.08) 58%, transparent 80%);
  clip-path: polygon(0 0, 100% 0, 100% 64%, 0 100%);
  pointer-events: none;
  z-index: 0;
}

.page-about .about-hero > * {
  position: relative;
  z-index: 1;
}

.page-about .about-kicker {
  display: flex;
  align-items: center;
  gap: 10px;
  margin: 0 0 18px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.02em;
  color: var(--muted);
}

.page-about .about-kicker-code {
  display: inline-block;
  padding: 3px 8px;
  border: 1px solid var(--line);
  color: var(--spring);
}

.page-about .about-title {
  margin: 0 0 22px;
  font-size: 32px;
  line-height: 1.24;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--paper);
}

.page-about .about-lede {
  margin: 0 0 16px;
  max-width: 40em;
  font-size: 16.5px;
  line-height: 1.78;
  color: var(--about-ink-soft);
}

.page-about .about-hero-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 26px;
}

.page-about .about-stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .about-stat {
  background: var(--ink);
  padding: 16px 14px 18px;
}

.page-about .about-stat-num {
  display: block;
  font-family: var(--font-mono);
  font-size: 30px;
  line-height: 1;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: var(--spring);
}

.page-about .about-stat-unit {
  font-size: 15px;
  margin-left: 2px;
}

.page-about .about-stat-label {
  display: block;
  margin-top: 10px;
  font-size: 13px;
  line-height: 1.6;
  color: var(--muted);
}

/* ---------- 主体骨架 ---------- */

.page-about .about-body {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 28px;
  padding-bottom: 76px;
}

.page-about .about-index-title {
  margin: 0 0 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--line);
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--muted);
}

.page-about .about-index-list {
  display: flex;
  flex-wrap: wrap;
  gap: 4px 10px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-index-list a {
  display: flex;
  align-items: baseline;
  gap: 8px;
  padding: 7px 10px;
  font-size: 14px;
  line-height: 1.4;
  color: var(--muted);
  text-decoration: none;
  border-left: 2px solid transparent;
  transition: color 0.2s ease, border-color 0.2s ease;
}

.page-about .about-index-list a:hover,
.page-about .about-index-list a:focus-visible {
  color: var(--paper);
  border-left-color: var(--spring);
}

.page-about .about-index-num {
  font-family: var(--font-mono);
  font-size: 12px;
  color: var(--spring);
}

/* ---------- 章节通用 ---------- */

.page-about .about-sec {
  margin-bottom: 64px;
  scroll-margin-top: calc(var(--header-h) + 24px);
}

.page-about .about-sec:last-of-type {
  margin-bottom: 0;
}

.page-about .about-sec-head {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding-top: 16px;
  border-top: 1px solid var(--line);
  margin-bottom: 24px;
}

.page-about .about-h2 {
  margin: 0;
  font-size: 23px;
  line-height: 1.32;
  font-weight: 800;
  letter-spacing: -0.01em;
  color: var(--paper);
}

.page-about .about-p {
  margin: 0 0 18px;
  max-width: 40em;
  font-size: 16.5px;
  line-height: 1.78;
  color: var(--about-ink-soft);
}

.page-about .about-p--tight {
  margin-bottom: 0;
}

.page-about .about-inline-link {
  color: var(--spring);
  text-decoration: none;
  border-bottom: 1px solid rgba(46, 212, 122, 0.45);
  padding-bottom: 1px;
}

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

.page-about .about-figure {
  margin: 0 0 26px;
}

.page-about .img-frame {
  border: 1px solid var(--line);
  background: var(--slate);
  overflow: hidden;
}

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

.page-about .img-caption {
  display: block;
  margin-top: 10px;
  font-family: var(--font-mono);
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--muted);
}

.page-about .about-plate {
  margin-top: 26px;
  padding: 22px 20px;
  background: var(--panel);
  border: 1px solid var(--line);
  box-shadow: var(--shadow-panel);
}

.page-about .about-plate-title {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.04em;
  color: var(--autumn);
}

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

.page-about .about-check li {
  position: relative;
  padding-left: 20px;
  font-size: 15.5px;
  line-height: 1.72;
  color: var(--about-ink-soft);
}

.page-about .about-check li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  width: 8px;
  height: 2px;
  background: var(--spring);
}

/* ---------- 四季赛制 ---------- */

.page-about .about-season-intro {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 26px;
}

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

.page-about .season-grid {
  list-style: none;
  margin: 30px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
}

.page-about .season-card {
  background: var(--panel);
  border: 1px solid var(--line);
  border-top-width: 3px;
  border-top-style: solid;
  padding: 18px 16px 20px;
}

.page-about .season-card--spring { border-top-color: var(--spring); }
.page-about .season-card--summer { border-top-color: var(--summer); }
.page-about .season-card--autumn { border-top-color: var(--autumn); }
.page-about .season-card--winter { border-top-color: var(--winter); }

.page-about .season-card-phase {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.page-about .season-card-num {
  display: flex;
  align-items: baseline;
  gap: 4px;
  margin: 12px 0 10px;
  font-family: var(--font-mono);
  font-size: 36px;
  font-weight: 700;
  line-height: 1;
  color: var(--paper);
}

.page-about .season-card-num span {
  font-size: 13px;
  font-weight: 500;
  color: var(--muted);
}

.page-about .season-card-name {
  margin: 0 0 8px;
  font-size: 16px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .season-card-desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--muted);
}

/* ---------- 团队分工 ---------- */

.page-about .crew-grid {
  list-style: none;
  margin: 28px 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .crew-card {
  background: var(--panel);
  padding: 20px 18px 22px;
}

.page-about .crew-code {
  display: block;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.04em;
  color: var(--muted);
}

.page-about .crew-num {
  display: flex;
  align-items: baseline;
  gap: 4px;
  margin: 10px 0 12px;
  font-family: var(--font-mono);
  font-size: 40px;
  font-weight: 700;
  line-height: 1;
  color: var(--spring);
}

.page-about .crew-num small {
  font-size: 13px;
  font-weight: 500;
  color: var(--muted);
}

.page-about .crew-name {
  margin: 0 0 8px;
  font-size: 16px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .crew-desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--muted);
}

/* ---------- 多端阅读 ---------- */

.page-about .device-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 12px;
  margin-top: 26px;
}

.page-about .device-card {
  padding: 20px 18px 22px;
  background: var(--panel);
  border: 1px solid var(--line);
  border-left: 3px solid var(--winter);
}

.page-about .device-card:nth-child(1) { border-left-color: var(--spring); }
.page-about .device-card:nth-child(2) { border-left-color: var(--winter); }
.page-about .device-card:nth-child(3) { border-left-color: var(--summer); }

.page-about .device-label {
  display: block;
  margin-bottom: 10px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.page-about .device-name {
  margin: 0 0 10px;
  font-size: 17px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .device-desc {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--about-ink-soft);
}

/* ---------- 更新节拍 ---------- */

.page-about .beat-list {
  list-style: none;
  margin: 28px 0 0;
  padding: 0 0 0 20px;
  border-left: 1px solid var(--line);
}

.page-about .beat-item {
  position: relative;
  padding: 0 0 24px 18px;
}

.page-about .beat-item:last-child {
  padding-bottom: 4px;
}

.page-about .beat-item::before {
  content: "";
  position: absolute;
  left: -4px;
  top: 9px;
  width: 7px;
  height: 7px;
  background: var(--spring);
}

.page-about .beat-item:nth-child(2)::before { background: var(--summer); }
.page-about .beat-item:nth-child(3)::before { background: var(--autumn); }
.page-about .beat-item:nth-child(4)::before { background: var(--winter); }

.page-about .beat-time {
  display: block;
  margin-bottom: 6px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.02em;
  color: var(--autumn);
}

.page-about .beat-name {
  margin: 0 0 8px;
  font-size: 16.5px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .beat-desc {
  margin: 0;
  max-width: 38em;
  font-size: 14.5px;
  line-height: 1.72;
  color: var(--muted);
}

/* ---------- 合作生态 ---------- */

.page-about .eco-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1px;
  margin: 26px 0 26px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .eco-cell {
  background: var(--panel);
  padding: 20px 18px 22px;
}

.page-about .eco-num {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 44px;
  font-weight: 700;
  line-height: 1;
  color: var(--paper);
}

.page-about .eco-cell:nth-child(1) .eco-num { color: var(--spring); }
.page-about .eco-cell:nth-child(2) .eco-num { color: var(--winter); }
.page-about .eco-cell:nth-child(3) .eco-num { color: var(--autumn); }

.page-about .eco-name {
  margin: 0 0 8px;
  font-size: 16px;
  font-weight: 700;
  color: var(--paper);
}

.page-about .eco-desc {
  margin: 0;
  font-size: 14px;
  line-height: 1.7;
  color: var(--muted);
}

/* ---------- 主体信息 ---------- */

.page-about .about-contact {
  padding: 24px 20px;
  background: var(--panel);
  border: 1px solid var(--line);
  box-shadow: var(--shadow-panel);
}

.page-about .about-contact .contact-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 14px;
}

.page-about .about-contact .contact-item {
  display: grid;
  gap: 4px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--about-line-soft);
}

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

.page-about .about-contact .contact-key {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.06em;
  color: var(--muted);
}

.page-about .contact-val {
  font-size: 16px;
  line-height: 1.6;
  color: var(--paper);
  overflow-wrap: anywhere;
}

.page-about .about-contact-note {
  margin: 20px 0 0;
  max-width: 40em;
  font-size: 14px;
  line-height: 1.75;
  color: var(--muted);
}

/* ---------- 响应式 ---------- */

@media (min-width: 640px) {
  .page-about .about-title {
    font-size: 40px;
  }

  .page-about .about-h2 {
    font-size: 26px;
  }

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

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

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

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

@media (min-width: 1024px) {
  .page-about .about-hero {
    grid-template-columns: minmax(0, 1.4fr) minmax(0, 0.6fr);
    align-items: end;
    gap: 48px;
    padding-top: 40px;
    padding-bottom: 72px;
  }

  .page-about .about-hero::before {
    right: -40px;
    width: 420px;
    height: 380px;
  }

  .page-about .about-title {
    font-size: 52px;
    line-height: 1.16;
  }

  .page-about .about-body {
    grid-template-columns: 168px minmax(0, 1fr);
    gap: 52px;
  }

  .page-about .about-index {
    position: sticky;
    top: calc(var(--header-h) + 32px);
    align-self: start;
  }

  .page-about .about-index-list {
    flex-direction: column;
    flex-wrap: nowrap;
    gap: 2px;
  }

  .page-about .about-index-list a {
    padding: 8px 10px;
  }

  .page-about .about-h2 {
    font-size: 32px;
  }

  .page-about .about-season-intro {
    grid-template-columns: minmax(0, 0.42fr) minmax(0, 1fr);
    gap: 36px;
    align-items: start;
  }

  .page-about .season-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .crew-grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }

  .page-about .about-figure {
    margin-bottom: 30px;
  }

  .page-about .about-contact {
    padding: 30px 28px;
  }

  .page-about .about-contact .contact-item {
    grid-template-columns: 132px minmax(0, 1fr);
    align-items: baseline;
    gap: 16px;
  }
}

@media (min-width: 1280px) {
  .page-about .about-title {
    font-size: 56px;
  }

  .page-about .about-stat {
    padding: 20px 18px 22px;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-index-list a {
    transition: none;
  }
}