.page-about {
  --tl-gutter: 34px;
  --tl-axis: 7px;
  --tl-dot-size: 14px;
  color: var(--graphite);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  isolation: isolate;
  overflow: hidden;
  padding: clamp(24px, 5vw, 60px) 0 clamp(30px, 5vw, 54px);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: -50px -18% -20px -12%;
  background-image:
    linear-gradient(to right, rgba(124, 140, 150, 0.14) 1px, transparent 1px),
    linear-gradient(to bottom, rgba(124, 140, 150, 0.14) 1px, transparent 1px);
  background-size: var(--unit) var(--unit);
  -webkit-mask-image: radial-gradient(95% 75% at 12% 8%, #000 0%, rgba(0, 0, 0, 0.3) 48%, transparent 80%);
  mask-image: radial-gradient(95% 75% at 12% 8%, #000 0%, rgba(0, 0, 0, 0.3) 48%, transparent 80%);
  pointer-events: none;
  z-index: -1;
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  right: -8%;
  top: 4%;
  width: min(320px, 46%);
  aspect-ratio: 1;
  border: 1px solid var(--line-strong);
  transform: rotate(45deg);
  opacity: 0.28;
  pointer-events: none;
  z-index: -1;
}

.page-about .about-hero-title {
  font-family: var(--font-display);
  font-weight: 800;
  letter-spacing: -0.01em;
  line-height: 1.04;
  font-size: clamp(2.3rem, 7.2vw, 4.9rem);
  color: var(--paper);
  max-width: 17ch;
  margin: 14px 0 0;
  text-shadow: 0 0 70px rgba(56, 224, 206, 0.16);
}

.page-about .about-lede {
  margin-top: clamp(16px, 2.6vw, 24px);
  max-width: 60ch;
  color: var(--graphite);
}

.page-about .readout {
  list-style: none;
  margin: clamp(28px, 4.5vw, 48px) 0 0;
  padding: clamp(20px, 3vw, 26px) 0 0;
  border-top: 1px solid var(--line);
  display: grid;
  grid-template-columns: 1fr;
  gap: 20px;
}

.page-about .readout li {
  display: grid;
  gap: 6px;
  padding-left: 16px;
  border-left: 2px solid rgba(56, 224, 206, 0.28);
}

.page-about .readout-k {
  font-size: 11px;
  letter-spacing: 0.22em;
  color: var(--cyan);
  text-transform: uppercase;
}

.page-about .readout-v {
  font-family: var(--font-display);
  font-weight: 700;
  font-size: clamp(1.5rem, 3.6vw, 2.2rem);
  line-height: 1;
  color: var(--paper);
}

.page-about .readout-n {
  font-size: 13px;
  color: var(--silent);
}

/* ---------- 通用区块 ---------- */
.page-about .about-block {
  position: relative;
  padding: clamp(40px, 6.6vw, 84px) 0;
  border-top: 1px solid var(--line);
}

.page-about .about-head {
  max-width: 780px;
  margin-bottom: clamp(26px, 4vw, 44px);
}

.page-about .about-head h2 {
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: clamp(1.55rem, 3.6vw, 2.5rem);
  line-height: 1.3;
  color: var(--paper);
  margin: 10px 0 12px;
}

.page-about .about-head p {
  margin: 0;
  max-width: 64ch;
  color: var(--silent);
  line-height: 1.8;
}

/* ---------- 时间轴 ---------- */
.page-about .timeline {
  list-style: none;
  margin: 0;
  padding: 4px 0 0 var(--tl-gutter);
  position: relative;
}

.page-about .timeline::before {
  content: "";
  position: absolute;
  left: var(--tl-axis);
  top: 10px;
  bottom: 20px;
  width: 1px;
  background: linear-gradient(180deg, var(--cyan) 0%, rgba(56, 224, 206, 0.24) 46%, rgba(56, 224, 206, 0.04) 100%);
}

.page-about .tl-item {
  position: relative;
  padding-bottom: clamp(26px, 4vw, 42px);
}

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

.page-about .tl-dot {
  position: absolute;
  left: calc(var(--tl-axis) - var(--tl-gutter) - var(--tl-dot-size) / 2);
  top: 6px;
  width: var(--tl-dot-size);
  height: var(--tl-dot-size);
  border: 1px solid var(--cyan);
  background: var(--ink);
  transform: rotate(45deg);
}

.page-about .tl-dot::after {
  content: "";
  position: absolute;
  inset: 3px;
  background: var(--cyan);
  opacity: 0.6;
}

.page-about .tl-stage {
  margin: 0 0 10px;
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--cyan);
}

.page-about .tl-body {
  background: var(--night);
  border: 1px solid var(--line);
  border-left: 2px solid rgba(56, 224, 206, 0.5);
  padding: 18px 20px 20px;
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - var(--cut)), calc(100% - var(--cut)) 100%, 0 100%);
  transition: border-color 220ms var(--ease), background 220ms var(--ease);
}

.page-about .tl-body:hover,
.page-about .tl-item:focus-within .tl-body {
  background: #12222C;
  border-color: rgba(56, 224, 206, 0.42);
}

.page-about .tl-body h3 {
  margin: 0 0 8px;
  font-family: var(--font-serif);
  font-size: 1.14rem;
  font-weight: 700;
  color: var(--paper);
}

.page-about .tl-body p {
  margin: 0;
  color: var(--silent);
  line-height: 1.78;
  font-size: 15px;
}

/* ---------- 分工矩阵 ---------- */
.page-about .crew-matrix {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 1px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .crew-cell {
  position: relative;
  background: var(--night);
  padding: 22px 20px 24px;
  outline: none;
  transition: background 220ms var(--ease);
}

.page-about .crew-cell::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  width: 0;
  height: 2px;
  background: linear-gradient(90deg, var(--cyan), var(--ember));
  transition: width 280ms var(--ease);
}

.page-about .crew-cell:hover,
.page-about .crew-cell:focus-visible {
  background: #12222C;
}

.page-about .crew-cell:hover::before,
.page-about .crew-cell:focus-visible::before {
  width: 100%;
}

.page-about .crew-cell:focus-visible {
  box-shadow: inset 0 0 0 2px var(--cyan);
}

.page-about .crew-num {
  display: block;
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--cyan);
  margin-bottom: 12px;
}

.page-about .crew-name {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.35rem;
  letter-spacing: 0.01em;
  color: var(--paper);
}

.page-about .crew-duty {
  margin: 0 0 14px;
  font-size: 14px;
  line-height: 1.76;
  color: var(--silent);
}

.page-about .crew-partner {
  margin: 0;
  font-size: 12px;
  color: var(--silent);
  padding-top: 12px;
  border-top: 1px dashed var(--line-soft);
  transition: color 220ms var(--ease);
}

.page-about .crew-partner .mono {
  color: var(--ember);
  margin-right: 8px;
  letter-spacing: 0.12em;
}

.page-about .crew-cell:hover .crew-partner,
.page-about .crew-cell:focus-visible .crew-partner {
  color: var(--graphite);
}

.page-about .crew-figure {
  margin-top: clamp(24px, 3.4vw, 38px);
}

/* ---------- 覆盖 ---------- */
.page-about .coverage-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(24px, 3.4vw, 42px);
  align-items: start;
}

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

.page-about .cov-item {
  padding: 18px 0;
  border-top: 1px solid var(--line);
}

.page-about .cov-item:first-child {
  border-top: 0;
  padding-top: 0;
}

.page-about .cov-v {
  display: block;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(1.7rem, 4.4vw, 2.6rem);
  line-height: 1;
  color: var(--paper);
}

.page-about .cov-k {
  display: block;
  margin-top: 8px;
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--cyan);
}

.page-about .cov-d {
  margin: 10px 0 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--silent);
  max-width: 44ch;
}

/* ---------- 更新节奏 ---------- */
.page-about .cadence-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .cadence-item {
  display: grid;
  grid-template-columns: 1fr auto;
  gap: 4px 18px;
  padding: 20px 0;
  border-top: 1px solid var(--line);
}

.page-about .cadence-item:first-child {
  border-top: 1px solid var(--line-strong);
}

.page-about .cadence-num {
  grid-column: 1;
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--cyan);
}

.page-about .cadence-name {
  grid-column: 1;
  margin: 0;
  font-family: var(--font-serif);
  font-size: 1.12rem;
  font-weight: 700;
  color: var(--paper);
}

.page-about .cadence-desc {
  grid-column: 1;
  margin: 2px 0 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--silent);
  max-width: 58ch;
}

.page-about .cadence-freq {
  grid-column: 2;
  grid-row: 1 / span 3;
  align-self: center;
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--ember);
  border: 1px solid rgba(255, 122, 61, 0.4);
  padding: 6px 10px;
  white-space: nowrap;
}

/* ---------- 坐标主张 ---------- */
.page-about .origin-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: clamp(24px, 3.6vw, 46px);
  align-items: center;
}

.page-about .origin-claim {
  margin: 0 0 20px;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: clamp(1.5rem, 4vw, 2.5rem);
  line-height: 1.44;
  color: var(--paper);
}

.page-about .origin-accent {
  color: var(--ember);
  position: relative;
}

.page-about .origin-accent::after {
  content: "";
  position: absolute;
  left: 0;
  right: 0;
  bottom: -6px;
  height: 2px;
  background: linear-gradient(90deg, var(--ember), transparent);
}

.page-about .origin-note {
  margin: 0 0 14px;
  max-width: 52ch;
  color: var(--silent);
  line-height: 1.85;
}

.page-about .origin-note:last-child {
  margin-bottom: 0;
}

/* ---------- 长期方向 ---------- */
.page-about .upkeep-grid {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr;
  gap: 22px;
}

.page-about .upkeep-item {
  position: relative;
  padding: 22px 20px 24px;
  background: var(--night);
  border: 1px solid var(--line);
  clip-path: polygon(var(--cut) 0, 100% 0, 100% 100%, 0 100%, 0 var(--cut));
}

.page-about .upkeep-num {
  display: block;
  font-size: 12px;
  letter-spacing: 0.2em;
  color: var(--ember);
  margin-bottom: 12px;
}

.page-about .upkeep-item h3 {
  margin: 0 0 10px;
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.3rem;
  color: var(--paper);
}

.page-about .upkeep-item p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.78;
  color: var(--silent);
}

/* ---------- 行动区 ---------- */
.page-about .about-cta {
  position: relative;
  border-top: 1px solid var(--line-strong);
  padding: clamp(38px, 6vw, 76px) 0 clamp(44px, 6vw, 80px);
  background:
    radial-gradient(120% 130% at 88% 0%, rgba(255, 122, 61, 0.12) 0%, transparent 58%),
    radial-gradient(90% 120% at 6% 100%, rgba(56, 224, 206, 0.1) 0%, transparent 62%);
}

.page-about .about-cta-inner {
  display: grid;
  grid-template-columns: 1fr;
  gap: 24px;
  position: relative;
}

.page-about .about-cta-copy h2 {
  margin: 0 0 12px;
  font-family: var(--font-serif);
  font-weight: 700;
  font-size: clamp(1.5rem, 3.4vw, 2.2rem);
  color: var(--paper);
}

.page-about .about-cta-copy p {
  margin: 0;
  max-width: 58ch;
  color: var(--silent);
  line-height: 1.8;
}

.page-about .about-cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

.page-about .about-top {
  align-self: end;
  justify-self: start;
  font-size: 12px;
  letter-spacing: 0.16em;
  color: var(--silent);
  text-decoration: none;
  border-bottom: 1px solid var(--line-soft);
  padding-bottom: 3px;
  transition: color 220ms var(--ease), border-color 220ms var(--ease);
}

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

/* ---------- 响应式 ---------- */
@media (min-width: 720px) {
  .page-about .readout {
    grid-template-columns: repeat(3, 1fr);
    gap: 30px;
  }

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

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

@media (min-width: 900px) {
  .page-about {
    --tl-gutter: 226px;
    --tl-axis: 166px;
  }

  .page-about .tl-stage {
    position: absolute;
    left: 0;
    top: 8px;
    width: calc(var(--tl-axis) - 30px);
    text-align: right;
    margin: 0;
  }

  .page-about .tl-dot {
    top: 8px;
  }

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

  .page-about .coverage-grid {
    grid-template-columns: 1.04fr 0.96fr;
  }

  .page-about .origin-grid {
    grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.15fr);
  }

  .page-about .upkeep-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 26px;
  }

  .page-about .about-cta-inner {
    grid-template-columns: minmax(0, 1.2fr) minmax(0, 1fr);
    grid-template-areas:
      "copy actions"
      "copy top";
    align-items: start;
    column-gap: 48px;
  }

  .page-about .about-cta-copy {
    grid-area: copy;
  }

  .page-about .about-cta-actions {
    grid-area: actions;
    justify-content: flex-start;
  }

  .page-about .about-top {
    grid-area: top;
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .tl-body,
  .page-about .crew-cell,
  .page-about .crew-cell::before,
  .page-about .about-top {
    transition-duration: 1ms;
  }
}