.page-about {
  --about-measure: 60ch;
  --about-soft-line: rgba(30, 66, 87, 0.42);
  background: var(--deep);
  color: var(--silver);
  font-family: var(--font-body);
  overflow-x: hidden;
}

.page-about img {
  display: block;
  max-width: 100%;
  height: auto;
}

/* ---------- 首屏 ---------- */

.page-about .about-hero {
  position: relative;
  padding: 36px 0 56px;
  border-bottom: 1px solid var(--line);
  background:
    radial-gradient(900px 360px at 94% -12%, rgba(23, 224, 200, 0.16), transparent 72%),
    linear-gradient(180deg, var(--hull) 0%, var(--deep) 78%);
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  pointer-events: none;
  background-image:
    linear-gradient(to right, var(--about-soft-line) 1px, transparent 1px),
    linear-gradient(to bottom, var(--about-soft-line) 1px, transparent 1px);
  background-size: 96px 96px;
  -webkit-mask-image: linear-gradient(180deg, #000 0%, transparent 88%);
  mask-image: linear-gradient(180deg, #000 0%, transparent 88%);
}

.page-about .about-hero > .shell {
  position: relative;
}

.page-about .about-kicker {
  margin: 22px 0 0;
  font-size: 12px;
  letter-spacing: 0.18em;
  color: var(--amber);
}

.page-about .about-title {
  margin: 14px 0 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(32px, 7.4vw, 72px);
  line-height: 1.02;
  letter-spacing: -0.03em;
  color: var(--white);
}

.page-about .about-lede {
  margin: 22px 0 0;
  max-width: 56ch;
  font-size: 16px;
  line-height: 1.85;
  color: var(--silver);
}

.page-about .about-figures {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1px;
  margin-top: 34px;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .figure-cell {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 16px 14px;
  background: var(--deep);
}

.page-about .figure-num {
  font-size: clamp(28px, 6vw, 42px);
  line-height: 1;
  color: var(--white);
  letter-spacing: 0.02em;
}

.page-about .figure-unit {
  font-size: 0.46em;
  margin-left: 2px;
  color: var(--cyan);
}

.page-about .figure-label {
  font-size: 13px;
  line-height: 1.5;
  color: var(--mist);
}

/* ---------- 通用章节 ---------- */

.page-about .section {
  padding: 52px 0;
  border-bottom: 1px solid var(--line);
}

.page-about .section:last-of-type {
  border-bottom: 0;
}

.page-about .section-head {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 24px;
}

.page-about .section-mark {
  flex: none;
  width: 10px;
  height: 10px;
  background: var(--cyan);
}

.page-about .section-title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(22px, 4.4vw, 34px);
  line-height: 1.22;
  letter-spacing: -0.015em;
  color: var(--white);
}

.page-about .about-body p {
  max-width: var(--about-measure);
  margin: 0 0 1.15em;
  font-size: 16px;
  line-height: 1.85;
  color: var(--silver);
}

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

.page-about .about-body a,
.page-about .verify-note a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid var(--steel);
  transition: border-color 180ms var(--ease), color 180ms var(--ease);
}

.page-about .about-body a:hover,
.page-about .verify-note a:hover,
.page-about .about-body a:focus-visible,
.page-about .verify-note a:focus-visible {
  color: var(--cyan-soft);
  border-bottom-color: var(--cyan);
  outline: none;
}

.page-about .about-lead {
  max-width: 54ch;
  margin: 0 0 26px;
  font-size: 16px;
  line-height: 1.85;
  color: var(--silver);
}

/* ---------- 通栏色块 ---------- */

.page-about .break-band {
  position: relative;
  overflow: hidden;
  padding: 40px 0;
  background: linear-gradient(102deg, var(--cyan) 0%, var(--cyan-soft) 62%, var(--cyan) 100%);
  color: var(--deep);
}

.page-about .break-band::after {
  content: "";
  position: absolute;
  top: -80px;
  right: -50px;
  width: 240px;
  height: 240px;
  border: 1px solid rgba(6, 23, 37, 0.28);
  transform: rotate(18deg);
  pointer-events: none;
}

.page-about .break-line {
  position: relative;
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(24px, 6vw, 54px);
  line-height: 1.06;
  letter-spacing: -0.025em;
  color: var(--deep);
}

.page-about .break-sub {
  position: relative;
  margin: 12px 0 0;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.2em;
  color: rgba(6, 23, 37, 0.66);
}

/* ---------- 三条价值主线 ---------- */

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

.page-about .value-item {
  padding: 26px 0 28px;
  border-top: 1px solid var(--line);
}

.page-about .value-item:last-child {
  border-bottom: 1px solid var(--line);
}

.page-about .value-index {
  display: block;
  font-size: 44px;
  line-height: 1;
  letter-spacing: 0.04em;
  color: var(--grid);
  animation: about-index-in 620ms var(--ease) both;
}

.page-about .value-item:nth-child(2) .value-index {
  animation-delay: 90ms;
}

.page-about .value-item:nth-child(3) .value-index {
  animation-delay: 180ms;
}

@keyframes about-index-in {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

.page-about .value-title {
  margin: 12px 0 12px;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(20px, 3.8vw, 28px);
  line-height: 1.3;
  letter-spacing: -0.01em;
  color: var(--white);
}

.page-about .value-text {
  max-width: 56ch;
  margin: 0 0 14px;
  font-size: 16px;
  line-height: 1.8;
  color: var(--silver);
}

.page-about .value-text a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid var(--steel);
  transition: border-color 180ms var(--ease), color 180ms var(--ease);
}

.page-about .value-text a:hover,
.page-about .value-text a:focus-visible {
  color: var(--cyan-soft);
  border-bottom-color: var(--cyan);
  outline: none;
}

.page-about .value-meta {
  margin: 0;
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--cyan);
}

/* ---------- 五步流程 ---------- */

.page-about .steps {
  list-style: none;
  display: grid;
  gap: 1px;
  margin: 0;
  padding: 0;
  background: var(--line);
  border: 1px solid var(--line);
}

.page-about .step {
  position: relative;
  padding: 18px 16px;
  background: var(--hull);
  transition: background-color 180ms var(--ease);
}

.page-about .step:focus-visible {
  outline: 2px solid var(--cyan);
  outline-offset: -2px;
}

.page-about .step-mark {
  display: block;
  width: 12px;
  height: 12px;
  margin-bottom: 12px;
  background: transparent;
  border: 1px solid var(--cyan);
  transition: background-color 180ms var(--ease);
}

.page-about .step-name {
  display: block;
  font-size: 15px;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: var(--white);
}

.page-about .step-note {
  display: block;
  margin-top: 8px;
  font-size: 13px;
  line-height: 1.7;
  color: var(--mist);
}

.page-about .verify-aside {
  margin-top: 28px;
  max-width: 560px;
}

.page-about .verify-note {
  margin: 16px 0 0;
  font-size: 13px;
  line-height: 1.7;
  color: var(--mist);
}

/* ---------- 两端差异 ---------- */

.page-about .dual {
  margin-top: 26px;
  border: 1px solid var(--line);
  background: var(--hull);
}

.page-about .dual-radio {
  position: absolute;
  width: 1px;
  height: 1px;
  opacity: 0;
  pointer-events: none;
}

.page-about .dual-tabs {
  display: flex;
  border-bottom: 1px solid var(--line);
}

.page-about .dual-tab {
  flex: 1 1 0;
  padding: 14px 8px;
  text-align: center;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--mist);
  cursor: pointer;
  user-select: none;
  border-right: 1px solid var(--line);
  transition: color 180ms var(--ease), background-color 180ms var(--ease);
}

.page-about .dual-tab:last-child {
  border-right: 0;
}

.page-about .dual-radio:focus-visible ~ .dual-tabs .dual-tab {
  outline: 1px solid var(--cyan);
  outline-offset: -3px;
}

.page-about .dual-radio#dual-android:checked ~ .dual-tabs .dual-tab[for="dual-android"],
.page-about .dual-radio#dual-pc:checked ~ .dual-tabs .dual-tab[for="dual-pc"] {
  color: var(--deep);
  background: var(--cyan);
}

.page-about .dual-panel {
  display: none;
  padding: 22px 16px 24px;
}

.page-about .dual-radio#dual-android:checked ~ .dual-panels .dual-panel--android,
.page-about .dual-radio#dual-pc:checked ~ .dual-panels .dual-panel--pc {
  display: block;
}

.page-about .dual-caption {
  margin: 0 0 14px;
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--mist);
}

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

.page-about .level-row {
  display: flex;
  align-items: center;
  gap: 10px;
}

.page-about .level-bar {
  flex: none;
  width: 14px;
  height: 14px;
  border: 1px solid var(--cyan);
}

.page-about .level-bar--filled {
  background: var(--cyan);
}

.page-about .level-name {
  font-size: 14px;
  line-height: 1.5;
  color: var(--silver);
}

.page-about .dual-foot {
  margin: 18px 0 0;
  padding-top: 14px;
  border-top: 1px solid var(--line);
  font-size: 13px;
  line-height: 1.7;
  color: var(--mist);
}

/* ---------- 页尾 ---------- */

.page-about .about-tail {
  padding-top: 52px;
}

.page-about .tail-grid {
  margin-top: 28px;
}

.page-about .tail-title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 800;
  font-size: clamp(22px, 4.4vw, 34px);
  line-height: 1.22;
  letter-spacing: -0.015em;
  color: var(--white);
}

.page-about .tail-text {
  max-width: 46ch;
  margin: 14px 0 0;
  font-size: 16px;
  line-height: 1.8;
  color: var(--silver);
}

.page-about .tail-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 22px;
}

/* ---------- 平板及以上 ---------- */

@media (min-width: 720px) {
  .page-about .about-hero {
    padding: 48px 0 72px;
  }

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

  .page-about .figure-cell {
    padding: 20px 18px;
  }

  .page-about .section {
    padding: 68px 0;
  }
}

@media (min-width: 860px) {
  .page-about .steps {
    grid-template-columns: repeat(5, minmax(0, 1fr));
  }

  .page-about .value-item {
    display: grid;
    grid-template-columns: 132px minmax(0, 1fr);
    gap: 32px;
    align-items: start;
    padding: 36px 0 38px;
  }

  .page-about .value-index {
    font-size: 64px;
  }

  .page-about .value-title {
    margin-top: 0;
  }

  .page-about .value-body {
    padding-left: 6px;
  }

  .page-about .verify-aside {
    margin-left: auto;
    margin-top: -8px;
  }

  .page-about .tail-grid {
    display: grid;
    grid-template-columns: minmax(0, 5fr) minmax(0, 7fr);
    gap: 40px;
    align-items: start;
  }

  .page-about .tail-text {
    margin-top: 0;
  }

  .page-about .tail-actions {
    grid-column: 2;
    margin-top: 8px;
  }
}

@media (hover: hover) and (min-width: 860px) {
  .page-about .step-note {
    max-height: 0;
    margin-top: 0;
    overflow: hidden;
    opacity: 0;
    transition: max-height 280ms var(--ease), opacity 240ms var(--ease), margin-top 280ms var(--ease);
  }

  .page-about .step:hover .step-note,
  .page-about .step:focus-within .step-note {
    max-height: 140px;
    margin-top: 8px;
    opacity: 1;
  }

  .page-about .step:hover {
    background: var(--steel);
  }

  .page-about .step:hover .step-mark,
  .page-about .step:focus-within .step-mark {
    background: var(--cyan);
  }
}

@media (prefers-reduced-motion: reduce) {
  .page-about .value-index {
    animation: none;
  }

  .page-about .step-note,
  .page-about .step-mark,
  .page-about .step,
  .page-about .dual-tab {
    transition: none;
  }
}
<<<END>>>