.page-about {
  --about-line-soft: rgba(63, 224, 208, 0.14);
  --about-card-bg: rgba(12, 34, 51, 0.86);
}

.page-about .about-hero {
  padding: clamp(20px, 5vw, 44px) 0 clamp(30px, 5vw, 60px);
  border-bottom: 1px solid var(--grid-line);
  background-image:
    linear-gradient(90deg, var(--grid-line) 1px, transparent 1px),
    linear-gradient(180deg, var(--grid-line) 1px, transparent 1px);
  background-size: 88px 88px;
  background-position: -1px -1px;
}

.page-about .about-hero__head {
  display: grid;
  gap: 14px;
  margin-top: 18px;
}

.page-about h1 {
  font-family: var(--font-display);
  font-size: clamp(30px, 7.4vw, var(--fz-5xl));
  font-weight: 400;
  line-height: 1.08;
  letter-spacing: -0.02em;
  color: var(--chalk-white);
  max-width: 20ch;
  margin: 0;
}

.page-about .about-hero__lede {
  max-width: 62ch;
  font-size: var(--fz-base);
  line-height: 1.85;
  color: var(--slate-mute);
  margin: 0;
}

.page-about .about-hero__grid {
  display: grid;
  gap: 16px;
  margin-top: clamp(22px, 4vw, 36px);
}

.page-about .about-hero__figure {
  border-radius: var(--r-card);
  overflow: hidden;
  border: 1px solid var(--about-line-soft);
  margin: 0;
}

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

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

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

.page-about .about-fact__label {
  font-size: var(--fz-xs);
  letter-spacing: 0.16em;
  color: var(--slate-mute);
}

.page-about .about-fact__num {
  margin: 0;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: clamp(24px, 5.2vw, 34px);
  font-weight: 700;
  line-height: 1.05;
  color: var(--neon-cyan);
}

.page-about .about-fact__suffix {
  font-size: var(--fz-xs);
  font-weight: 400;
  color: var(--slate-mute);
  margin-left: 3px;
}

.page-about .about-sec {
  padding: clamp(38px, 6vw, 82px) 0;
  border-bottom: 1px solid var(--grid-line);
}

.page-about .about-sec__head {
  display: grid;
  gap: 10px;
  margin-bottom: clamp(22px, 4vw, 42px);
}

.page-about .about-sec__head h2 {
  margin: 0;
  font-family: var(--font-display);
  font-size: clamp(23px, 4.6vw, var(--fz-3xl));
  font-weight: 400;
  letter-spacing: -0.015em;
  line-height: 1.2;
  color: var(--chalk-white);
  max-width: 24ch;
}

.page-about .about-sec__lede {
  margin: 0;
  max-width: 58ch;
  color: var(--slate-mute);
  font-size: var(--fz-base);
  line-height: 1.8;
}

.page-about .about-split {
  display: grid;
  gap: 22px;
}

.page-about .about-prose p {
  margin: 0 0 16px;
  font-size: var(--fz-base);
  line-height: 1.85;
  color: var(--chalk-white);
}

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

.page-about .about-link {
  color: var(--neon-cyan);
  text-decoration: none;
  border-bottom: 1px solid var(--aqua-dim);
  padding-bottom: 1px;
  transition: color 0.25s var(--ease), border-color 0.25s var(--ease);
}

.page-about .about-link:hover,
.page-about .about-link:focus-visible {
  color: var(--ember-glow);
  border-bottom-color: var(--lava-orange);
}

.page-about .about-note {
  padding: 20px 18px;
  border: 1px solid var(--grid-line);
  border-radius: var(--r-card);
  background: var(--navy-deck);
}

.page-about .about-note__label {
  margin: 0 0 14px;
  font-family: var(--font-mono);
  font-size: var(--fz-xs);
  letter-spacing: 0.2em;
  color: var(--neon-cyan);
}

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

.page-about .about-note__list li {
  display: grid;
  gap: 4px;
  padding-bottom: 11px;
  border-bottom: 1px dashed var(--grid-line);
}

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

.page-about .about-note__key {
  font-size: var(--fz-xs);
  letter-spacing: 0.14em;
  color: var(--slate-mute);
}

.page-about .about-note__val {
  font-size: var(--fz-sm);
  color: var(--chalk-white);
  line-height: 1.6;
}

/* ---------- 时间轴 ---------- */
.page-about .about-tl-section {
  padding: clamp(38px, 6vw, 82px) 0;
  background: var(--navy-deck);
  border-bottom: 1px solid var(--grid-line);
}

.page-about .tl-shell {
  display: grid;
  gap: 20px;
}

.page-about .tl-index {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .tl-index__link {
  display: inline-block;
  padding: 6px 14px;
  border-radius: var(--r-pill);
  border: 1px solid var(--grid-line);
  font-family: var(--font-mono);
  font-size: var(--fz-sm);
  letter-spacing: 0.1em;
  color: var(--slate-mute);
  text-decoration: none;
  transition: color 0.25s var(--ease), background 0.25s var(--ease), border-color 0.25s var(--ease);
}

.page-about .tl-index__link:hover,
.page-about .tl-index__link:focus-visible {
  color: var(--deep-abyss);
  background: var(--neon-cyan);
  border-color: var(--neon-cyan);
}

.page-about .tl {
  position: relative;
  display: grid;
  gap: 18px;
}

.page-about .tl::before {
  content: "";
  position: absolute;
  top: 6px;
  bottom: 6px;
  left: 6px;
  width: 1px;
  background: linear-gradient(180deg, var(--neon-cyan), var(--aqua-dim) 40%, var(--grid-line));
}

.page-about .tl-item {
  position: relative;
  padding-left: 28px;
}

.page-about .tl-node {
  position: absolute;
  left: 0;
  top: 22px;
  width: 13px;
  height: 13px;
  border-radius: 50%;
  background: var(--deep-abyss);
  border: 2px solid var(--neon-cyan);
  box-shadow: 0 0 0 4px var(--about-line-soft);
}

.page-about .tl-card {
  display: grid;
  gap: 10px;
  padding: 20px 18px;
  background: var(--deep-abyss);
  border: 1px solid var(--grid-line);
  border-radius: var(--r-card);
  transition: border-color 0.3s var(--ease);
}

.page-about .tl-card:hover,
.page-about .tl-card:focus-within {
  border-color: var(--aqua-dim);
}

.page-about .tl-card__year {
  margin: 0;
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--fz-lg);
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--lava-orange);
}

.page-about .tl-card__title {
  margin: 0;
  font-size: var(--fz-md);
  font-weight: 500;
  line-height: 1.4;
  color: var(--chalk-white);
}

.page-about .tl-card__text {
  margin: 0;
  font-size: var(--fz-sm);
  line-height: 1.8;
  color: var(--slate-mute);
}

.page-about .tl-stats {
  list-style: none;
  margin: 4px 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.page-about .tl-stat {
  flex: 1 1 88px;
  display: grid;
  gap: 2px;
  padding: 9px 11px;
  border-radius: var(--r-sm);
  border: 1px solid transparent;
  background: rgba(18, 57, 90, 0.5);
  transition: border-color 0.3s var(--ease), background 0.3s var(--ease);
}

.page-about .tl-card:hover .tl-stat,
.page-about .tl-card:focus-within .tl-stat {
  border-color: var(--aqua-dim);
  background: var(--inner-blue);
}

.page-about .tl-stat__num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--fz-base);
  font-weight: 700;
  color: var(--neon-cyan);
}

.page-about .tl-stat__label {
  font-size: var(--fz-xs);
  letter-spacing: 0.06em;
  color: var(--slate-mute);
}

/* ---------- 流程 ---------- */
.page-about .proc-grid {
  display: grid;
  gap: 22px;
}

.page-about .proc-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 16px;
}

.page-about .proc-step {
  padding: 16px 16px 16px 18px;
  border-left: 2px solid var(--aqua-dim);
  border-radius: 0 var(--r-sm) var(--r-sm) 0;
  background: linear-gradient(90deg, rgba(18, 57, 90, 0.55), rgba(12, 34, 51, 0.2));
  transition: border-color 0.3s var(--ease);
}

.page-about .proc-step:hover {
  border-left-color: var(--lava-orange);
}

.page-about .proc-step__no {
  margin: 0 0 6px;
  font-family: var(--font-mono);
  font-size: var(--fz-xs);
  letter-spacing: 0.2em;
  color: var(--lava-orange);
}

.page-about .proc-step__title {
  margin: 0 0 6px;
  font-size: var(--fz-md);
  font-weight: 500;
  color: var(--chalk-white);
}

.page-about .proc-step__text {
  margin: 0;
  font-size: var(--fz-sm);
  line-height: 1.8;
  color: var(--slate-mute);
}

.page-about .proc-foot {
  margin: 18px 0 0;
  font-size: var(--fz-sm);
  line-height: 1.8;
  color: var(--slate-mute);
}

.page-about .about-proc-figure {
  margin: 0;
  border-radius: var(--r-card);
  overflow: hidden;
  border: 1px solid var(--grid-line);
  background: var(--navy-deck);
}

.page-about .about-figcap {
  padding: 10px 14px 12px;
  font-size: var(--fz-xs);
  letter-spacing: 0.04em;
  color: var(--slate-mute);
  background: var(--navy-deck);
}

/* ---------- 团队 ---------- */
.page-about .about-sec--team {
  background:
    radial-gradient(120% 90% at 100% 0%, rgba(30, 140, 134, 0.16), transparent 62%);
}

.page-about .team-grid {
  display: grid;
  gap: 22px;
}

.page-about .team-roles {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 10px;
}

.page-about .role {
  display: grid;
  grid-template-columns: 46px minmax(0, 1fr);
  gap: 14px;
  align-items: start;
  padding: 14px 16px;
  border-radius: var(--r-sm);
  background: var(--about-card-bg);
  border: 1px solid var(--grid-line);
  transition: border-color 0.3s var(--ease);
}

.page-about .role:hover {
  border-color: var(--aqua-dim);
}

.page-about .role__num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--fz-xl);
  font-weight: 700;
  line-height: 1;
  color: var(--neon-cyan);
}

.page-about .role__name {
  margin: 0 0 4px;
  font-size: var(--fz-base);
  font-weight: 500;
  color: var(--chalk-white);
}

.page-about .role__desc {
  margin: 0;
  font-size: var(--fz-sm);
  line-height: 1.7;
  color: var(--slate-mute);
}

.page-about .tree {
  margin-top: 24px;
  padding-top: 4px;
}

.page-about .tree__root {
  display: inline-block;
  margin: 0;
  padding: 9px 22px;
  border-radius: var(--r-pill);
  background: var(--lava-orange);
  color: var(--deep-abyss);
  font-size: var(--fz-sm);
  font-weight: 700;
  letter-spacing: 0.1em;
}

.page-about .tree__stem {
  display: block;
  width: 1px;
  height: 18px;
  margin: 0 auto;
  background: var(--aqua-dim);
}

.page-about .tree__branches {
  display: grid;
  gap: 14px;
  position: relative;
  padding-top: 18px;
}

.page-about .branch {
  position: relative;
  padding: 14px 15px;
  border-radius: var(--r-card);
  border: 1px dashed var(--aqua-dim);
  background: var(--deep-abyss);
  transition: border-color 0.3s var(--ease), border-style 0.3s var(--ease);
}

.page-about .branch:hover,
.page-about .branch:focus-within {
  border-style: solid;
  border-color: var(--neon-cyan);
}

.page-about .branch::before {
  content: "";
  position: absolute;
  top: -18px;
  left: 50%;
  width: 1px;
  height: 18px;
  background: var(--aqua-dim);
}

.page-about .branch__title {
  margin: 0 0 6px;
  font-size: var(--fz-sm);
  font-weight: 500;
  color: var(--neon-cyan);
  letter-spacing: 0.04em;
}

.page-about .branch__text {
  margin: 0;
  font-size: var(--fz-xs);
  line-height: 1.75;
  color: var(--slate-mute);
}

.page-about .about-team-figure {
  margin: 0;
  border-radius: var(--r-card);
  overflow: hidden;
  border: 1px solid var(--grid-line);
  background: var(--navy-deck);
}

/* ---------- 合作 ---------- */
.page-about .partner-grid {
  display: grid;
  gap: 24px;
}

.page-about .partner-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  background: var(--grid-line);
  border: 1px solid var(--grid-line);
  border-radius: var(--r-card);
  overflow: hidden;
}

.page-about .partner-item {
  display: grid;
  gap: 4px;
  padding: 16px 14px;
  background: var(--navy-deck);
}

.page-about .partner-item__num {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--fz-xl);
  font-weight: 700;
  color: var(--neon-cyan);
  line-height: 1.05;
}

.page-about .partner-item__label {
  font-size: var(--fz-xs);
  line-height: 1.6;
  color: var(--slate-mute);
}

/* ---------- 联系 ---------- */
.page-about .about-sec--cta {
  border-bottom: 0;
}

.page-about .about-cta {
  display: grid;
  gap: 22px;
  padding: clamp(22px, 4vw, 40px);
  border-radius: var(--r-lg);
  border: 1px solid var(--aqua-dim);
  background:
    linear-gradient(135deg, rgba(30, 140, 134, 0.22), rgba(6, 20, 32, 0.9) 58%),
    var(--navy-deck);
}

.page-about .about-cta h2 {
  margin: 8px 0 0;
  font-family: var(--font-display);
  font-size: clamp(23px, 4.6vw, var(--fz-3xl));
  font-weight: 400;
  letter-spacing: -0.015em;
  line-height: 1.2;
  color: var(--chalk-white);
  max-width: 22ch;
}

.page-about .about-cta__text {
  margin: 14px 0 0;
  max-width: 58ch;
  font-size: var(--fz-base);
  line-height: 1.85;
  color: var(--slate-mute);
}

.page-about .about-cta__channels {
  display: grid;
  gap: 10px;
  margin-top: 20px;
}

.page-about .about-channel {
  display: grid;
  gap: 3px;
  padding: 12px 16px;
  border-radius: var(--r-sm);
  border: 1px solid var(--grid-line);
  background: rgba(6, 20, 32, 0.68);
  text-decoration: none;
  transition: border-color 0.25s var(--ease);
}

.page-about .about-channel:hover,
.page-about .about-channel:focus-visible {
  border-color: var(--neon-cyan);
}

.page-about .about-channel__key {
  font-size: var(--fz-xs);
  letter-spacing: 0.16em;
  color: var(--slate-mute);
}

.page-about .about-channel__val {
  font-family: var(--font-mono);
  font-size: var(--fz-sm);
  color: var(--chalk-white);
  word-break: break-word;
}

.page-about .about-cta__action {
  display: grid;
  gap: 12px;
  align-content: start;
}

.page-about .about-cta__hint {
  margin: 0;
  font-size: var(--fz-sm);
  line-height: 1.75;
  color: var(--slate-mute);
}

.page-about .about-cta__btn {
  justify-self: start;
  text-decoration: none;
}

.page-about .about-cta__link {
  justify-self: start;
  font-size: var(--fz-sm);
  color: var(--neon-cyan);
  text-decoration: none;
  border-bottom: 1px solid var(--aqua-dim);
  padding-bottom: 2px;
  transition: color 0.25s var(--ease), border-color 0.25s var(--ease);
}

.page-about .about-cta__link:hover,
.page-about .about-cta__link:focus-visible {
  color: var(--ember-glow);
  border-bottom-color: var(--lava-orange);
}

/* ---------- 平板 ---------- */
@media (min-width: 700px) {
  .page-about .about-hero__grid {
    grid-template-columns: minmax(0, 1.45fr) minmax(0, 1fr);
    align-items: stretch;
  }

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

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

  .page-about .about-cta {
    grid-template-columns: minmax(0, 1.6fr) minmax(0, 1fr);
    align-items: start;
  }

  .page-about .tree__branches {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 12px;
  }

  .page-about .tree__branches::before {
    content: "";
    position: absolute;
    top: 0;
    left: 16.6%;
    right: 16.6%;
    height: 1px;
    background: var(--aqua-dim);
  }
}

/* ---------- 桌面 ---------- */
@media (min-width: 960px) {
  .page-about .about-split {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: 36px;
    align-items: start;
  }

  .page-about .proc-grid {
    grid-template-columns: minmax(0, 6fr) minmax(0, 5fr);
    gap: 32px;
    align-items: start;
  }

  .page-about .team-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 4fr);
    gap: 32px;
    align-items: start;
  }

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

  .page-about .role:last-child {
    grid-column: 1 / -1;
  }

  .page-about .partner-grid {
    grid-template-columns: minmax(0, 7fr) minmax(0, 5fr);
    gap: 34px;
    align-items: start;
  }

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

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

  /* 时间轴左右交替 */
  .page-about .tl-shell {
    grid-template-columns: 132px minmax(0, 1fr);
    gap: 40px;
    align-items: start;
  }

  .page-about .tl-index {
    flex-direction: column;
    gap: 4px;
    position: sticky;
    top: 96px;
  }

  .page-about .tl-index__link {
    border-radius: var(--r-sm);
    padding: 8px 12px;
    text-align: center;
  }

  .page-about .tl::before {
    left: 50%;
  }

  .page-about .tl {
    gap: 26px;
  }

  .page-about .tl-item {
    width: 50%;
    padding-left: 0;
    padding-right: 38px;
  }

  .page-about .tl-item:nth-child(even) {
    margin-left: 50%;
    padding-left: 38px;
    padding-right: 0;
  }

  .page-about .tl-node {
    left: auto;
    right: -6px;
    top: 28px;
  }

  .page-about .tl-item:nth-child(even) .tl-node {
    right: auto;
    left: -6px;
  }

  .page-about .tl-card {
    padding: 22px 20px;
  }
}

@media (min-width: 1200px) {
  .page-about .about-facts {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }

  .page-about .about-prose p {
    font-size: var(--fz-md);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-link,
  .page-about .tl-index__link,
  .page-about .tl-card,
  .page-about .tl-stat,
  .page-about .proc-step,
  .page-about .role,
  .page-about .branch,
  .page-about .about-channel,
  .page-about .about-cta__link {
    transition: none;
  }
}