.page-about {
  --about-pad: clamp(3rem, 7vw, 6rem);
  display: block;
  overflow-x: hidden;
}

/* ---------- 首屏 ---------- */

.page-about .about-masthead {
  position: relative;
  padding-bottom: clamp(2rem, 5vw, 3.5rem);
  border-bottom: 1px solid var(--border);
  background:
    radial-gradient(120% 90% at 10% -20%, var(--wash) 0%, transparent 62%),
    var(--bg);
  overflow: hidden;
}

.page-about .about-masthead::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: 0;
  height: 1px;
  background: linear-gradient(90deg, var(--signal), rgba(255, 210, 0, 0) 62%);
  transform: rotate(-1.2deg);
  transform-origin: left center;
}

.page-about .about-masthead__inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1.75rem;
  padding-block: 1.75rem 2.25rem;
}

.page-about .about-kicker {
  margin: 0;
  font-size: 0.75rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-dim);
}

.page-about .about-kicker .mono {
  color: var(--accent-fg);
  letter-spacing: 0.08em;
}

.page-about .about-masthead__title {
  margin: 0.65rem 0 0;
  font-family: var(--font-sans);
  font-weight: 800;
  font-size: clamp(2rem, 7.8vw, 4rem);
  line-height: 1.08;
  letter-spacing: -0.02em;
  color: var(--text);
}

.page-about .about-masthead__dek {
  margin: 1.1rem 0 0;
  max-width: 54ch;
  font-size: clamp(1rem, 2.2vw, 1.125rem);
  line-height: 1.75;
  color: var(--text-dim);
}

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

.page-about .about-masthead__stats li {
  display: flex;
  flex-direction: column;
  gap: 0.15rem;
  min-width: 0;
  padding: 0.9rem 1rem;
  background: var(--bg-2);
}

.page-about .about-stat__num {
  font-family: var(--font-mono);
  font-size: clamp(1.5rem, 4.5vw, 2rem);
  font-weight: 700;
  line-height: 1.05;
  letter-spacing: -0.02em;
  color: var(--signal);
}

.page-about .about-stat__key {
  font-size: 0.8125rem;
  letter-spacing: 0.04em;
  color: var(--text-dim);
}

.page-about .about-masthead__figure {
  margin: clamp(1.5rem, 4vw, 2.5rem) 0 0;
}

.page-about .about-masthead__figure img,
.page-about .about-team__figure img,
.page-about .about-scenes__figure img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

/* ---------- 为什么是一套坐标 ---------- */

.page-about .about-why {
  padding-block: var(--about-pad);
}

.page-about .about-why__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1.25rem;
}

.page-about .about-why__title {
  margin: 0.4rem 0 0;
  font-size: clamp(1.5rem, 4.2vw, 2.25rem);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.015em;
  color: var(--text);
}

.page-about .about-why__body {
  max-width: 68ch;
}

.page-about .about-why__lead {
  margin: 0 0 1rem;
  font-size: clamp(1.125rem, 2.8vw, 1.5rem);
  font-weight: 600;
  line-height: 1.5;
  color: var(--text);
}

.page-about .about-why__body p {
  margin: 0 0 1rem;
  font-size: 1rem;
  line-height: 1.8;
  color: var(--text-dim);
}

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

/* ---------- 时间轴 ---------- */

.page-about .about-timeline {
  padding-block: var(--about-pad);
  background: var(--bg-2);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.page-about .about-timeline .section-head {
  max-width: 62ch;
  margin-bottom: clamp(1.75rem, 5vw, 3rem);
}

.page-about .about-track {
  position: relative;
  list-style: none;
  margin: 0;
  padding: 0 0 0 1.5rem;
}

.page-about .about-track::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.5rem;
  bottom: 0.75rem;
  width: 1px;
  background: var(--border);
}

.page-about .about-track__item {
  position: relative;
  padding-bottom: 2.25rem;
}

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

.page-about .about-track__item::before {
  content: "";
  position: absolute;
  left: -1.5rem;
  top: 0.55rem;
  width: 9px;
  height: 9px;
  transform: translateX(-4px);
  background: var(--bg-2);
  border: 1px solid var(--signal);
  transition: background-color 0.22s var(--ease), border-color 0.22s var(--ease),
    box-shadow 0.22s var(--ease);
}

.page-about .about-track__item:hover::before {
  background: var(--jade);
  border-color: var(--jade);
  box-shadow: 0 0 0 5px var(--wash);
}

.page-about .about-track__tick {
  display: inline-block;
  padding: 0.12rem 0.45rem;
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  background: var(--signal);
  color: var(--signal-ink);
}

.page-about .about-track__title {
  margin: 0.6rem 0 0.45rem;
  font-size: 1.125rem;
  font-weight: 700;
  line-height: 1.35;
  letter-spacing: -0.01em;
  color: var(--text);
  transition: color 0.22s var(--ease);
}

.page-about .about-track__item:hover .about-track__title {
  color: var(--accent-fg);
}

.page-about .about-track__text {
  margin: 0 0 0.5rem;
  max-width: 62ch;
  font-size: 0.9375rem;
  line-height: 1.78;
  color: var(--text-dim);
}

.page-about .about-track__note {
  margin: 0;
  max-width: 62ch;
  padding-left: 0.75rem;
  border-left: 2px solid var(--border);
  font-size: 0.875rem;
  line-height: 1.7;
  color: var(--text-dim);
}

/* ---------- 团队 ---------- */

.page-about .about-team {
  padding-block: var(--about-pad);
}

.page-about .about-team .section-head {
  max-width: 64ch;
  margin-bottom: clamp(1.75rem, 4vw, 2.75rem);
}

.page-about .about-roles {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1.25rem;
}

.page-about .about-role {
  position: relative;
  padding: 1.25rem 1.25rem 1.1rem;
  background: var(--bg-2);
  border: 1px solid var(--border);
  border-top: 2px solid var(--signal);
  box-shadow: 0 9px 0 -6px var(--border), 0 17px 0 -12px var(--border);
  outline-offset: 4px;
  transition: transform 0.25s var(--ease), border-color 0.25s var(--ease);
}

.page-about .about-role:hover {
  transform: translateY(-2px);
}

.page-about .about-role:focus-visible {
  outline: 2px solid var(--jade);
}

.page-about .about-role__count {
  margin: 0 0 0.5rem;
  font-size: 0.75rem;
  letter-spacing: 0.12em;
  color: var(--accent-fg);
}

.page-about .about-role__name {
  margin: 0 0 0.5rem;
  font-size: 1.125rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--text);
}

.page-about .about-role__desc {
  margin: 0;
  font-size: 0.9375rem;
  line-height: 1.75;
  color: var(--text-dim);
}

.page-about .about-role__more {
  margin: 0;
  padding-top: 0.75rem;
  max-height: 0;
  overflow: hidden;
  opacity: 0;
  border-top: 1px solid transparent;
  font-size: 0.875rem;
  line-height: 1.72;
  color: var(--text-dim);
  transition: max-height 0.35s var(--ease), opacity 0.3s var(--ease),
    border-color 0.3s var(--ease);
}

.page-about .about-role:hover .about-role__more,
.page-about .about-role:focus-within .about-role__more,
.page-about .about-role:focus .about-role__more {
  max-height: 14rem;
  opacity: 1;
  border-top-color: var(--border);
}

.page-about .about-team__figure {
  margin: clamp(1.75rem, 4vw, 2.5rem) 0 0;
}

/* ---------- 访问场景 ---------- */

.page-about .about-scenes-sec {
  padding-block: var(--about-pad);
  background: var(--bg-2);
  border-top: 1px solid var(--border);
  border-bottom: 1px solid var(--border);
}

.page-about .about-scenes-sec .section-head {
  max-width: 60ch;
  margin-bottom: clamp(1.5rem, 4vw, 2.5rem);
}

.page-about .about-scenes__wrap {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1.75rem;
}

.page-about .about-scenes {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--border);
}

.page-about .about-scene {
  border-bottom: 1px solid var(--border);
}

.page-about .about-scene__link {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0.35rem;
  padding: 1rem 0.85rem;
  border-left: 2px solid transparent;
  text-decoration: none;
  color: inherit;
  transition: background-color 0.22s var(--ease), border-color 0.22s var(--ease),
    padding-left 0.22s var(--ease);
}

.page-about .about-scene__link:hover,
.page-about .about-scene__link:focus-visible {
  background: var(--wash);
  border-left-color: var(--signal);
  padding-left: 1.15rem;
}

.page-about .about-scene__key {
  font-size: 1rem;
  font-weight: 700;
  letter-spacing: -0.005em;
  color: var(--text);
}

.page-about .about-scene__val {
  font-size: 0.9375rem;
  line-height: 1.72;
  color: var(--text-dim);
}

.page-about .about-scene__go {
  font-family: var(--font-mono);
  font-size: 0.8125rem;
  letter-spacing: 0.04em;
  color: var(--accent-fg);
}

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

/* ---------- 长期维护 ---------- */

.page-about .about-commit {
  padding-block: var(--about-pad);
}

.page-about .about-commit__inner {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 1.5rem;
}

.page-about .about-commit__title {
  margin: 0.4rem 0 0;
  font-size: clamp(1.5rem, 4.2vw, 2.25rem);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.015em;
  color: var(--text);
}

.page-about .about-quote {
  margin: 0 0 1.5rem;
  padding: 0.95rem 1.15rem;
  border-left: 4px solid var(--signal);
  background: var(--wash);
  font-size: clamp(1.0625rem, 2.2vw, 1.25rem);
  font-weight: 600;
  line-height: 1.65;
  color: var(--text);
}

.page-about .about-cadence {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-cadence li {
  display: grid;
  grid-template-columns: minmax(5.5rem, auto) minmax(0, 1fr);
  gap: 0.85rem;
  align-items: baseline;
  padding: 0.85rem 0;
  border-bottom: 1px dashed var(--border);
}

.page-about .about-cadence li:first-child {
  border-top: 1px dashed var(--border);
}

.page-about .about-cadence__k {
  font-size: 0.8125rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  color: var(--accent-fg);
}

.page-about .about-cadence__v {
  font-size: 0.9375rem;
  line-height: 1.72;
  color: var(--text-dim);
}

/* ---------- 收尾 ---------- */

.page-about .about-cta {
  padding-block: var(--about-pad);
  background: linear-gradient(118deg, var(--bg-3) 0%, var(--bg) 58%);
  border-top: 1px solid var(--border);
}

.page-about .about-cta__title {
  margin: 0 0 0.75rem;
  font-size: clamp(1.5rem, 4.2vw, 2.25rem);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: -0.015em;
  color: var(--text);
}

.page-about .about-cta__desc {
  margin: 0 0 1.5rem;
  max-width: 54ch;
  font-size: 1rem;
  line-height: 1.78;
  color: var(--text-dim);
}

.page-about .about-cta__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

/* ---------- 日间模式微调 ---------- */

@media (prefers-color-scheme: light) {
  .page-about .about-stat__num {
    color: var(--text);
  }

  .page-about .about-masthead {
    background:
      radial-gradient(120% 90% at 10% -20%, rgba(11, 15, 20, 0.05) 0%, transparent 62%),
      var(--bg);
  }
}

/* ---------- 窄屏 ---------- */

@media (max-width: 30rem) {
  .page-about .about-cadence li {
    grid-template-columns: minmax(0, 1fr);
    gap: 0.2rem;
  }

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

/* ---------- 桌面 ---------- */

@media (min-width: 900px) {
  .page-about .about-masthead__inner {
    grid-template-columns: minmax(0, 1.55fr) minmax(0, 1fr);
    align-items: end;
    gap: 3rem;
    padding-block: 3rem 3.5rem;
  }

  .page-about .about-why__grid {
    grid-template-columns: minmax(0, 0.72fr) minmax(0, 1.6fr);
    gap: 3.5rem;
  }

  .page-about .about-roles {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 1.5rem;
    align-items: start;
  }

  .page-about .about-role:nth-child(2) {
    margin-top: 2rem;
  }

  .page-about .about-role:nth-child(3) {
    margin-top: 4rem;
  }

  .page-about .about-scenes__wrap {
    grid-template-columns: minmax(0, 1.55fr) minmax(0, 0.85fr);
    gap: 2.5rem;
    align-items: start;
  }

  .page-about .about-scene__link {
    grid-template-columns: minmax(9rem, 0.6fr) minmax(0, 1.7fr) auto;
    align-items: baseline;
    gap: 1.25rem;
  }

  .page-about .about-commit__inner {
    grid-template-columns: minmax(0, 0.75fr) minmax(0, 1.35fr);
    gap: 3.5rem;
  }
}

@media (min-width: 960px) {
  .page-about .about-track {
    padding-left: 0;
  }

  .page-about .about-track::before {
    left: 50%;
    top: 0.6rem;
  }

  .page-about .about-track__item {
    width: 50%;
    padding-right: 2.75rem;
    padding-bottom: 2.75rem;
  }

  .page-about .about-track__item::before {
    left: auto;
    right: -4px;
    top: 0.5rem;
    transform: none;
  }

  .page-about .about-track__item:nth-child(even) {
    margin-left: 50%;
    padding-right: 0;
    padding-left: 2.75rem;
  }

  .page-about .about-track__item:nth-child(even)::before {
    right: auto;
    left: -4px;
  }
}
</style>