.page-about {
  --tl-pad: 40px;
  --about-pad: 64px;
  --about-gap: 48px;
  display: block;
}

@media (min-width: 768px) {
  .page-about {
    --tl-pad: 88px;
    --about-pad: 96px;
    --about-gap: 72px;
  }
}

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

.page-about .about-h2 {
  font-family: var(--font-display);
  font-size: clamp(28px, 4.4vw, 52px);
  font-weight: 800;
  line-height: 1.08;
  letter-spacing: -0.01em;
  color: var(--c-white);
  margin-block: 12px 0;
}

.page-about .about-mono {
  font-family: var(--font-mono);
  font-size: 0.92em;
  letter-spacing: 0.02em;
  color: var(--c-white);
  white-space: nowrap;
}

.page-about .about-cap {
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.1em;
  color: var(--c-dim);
  margin-top: 10px;
}

.page-about .about-head {
  max-width: 760px;
  margin-bottom: var(--about-gap);
}

.page-about .about-head--tight {
  margin-bottom: 40px;
}

.page-about .about-head__lede {
  margin-top: 16px;
  color: var(--c-silver);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding-top: 32px;
  padding-bottom: var(--about-pad);
}

.page-about .about-hero__main {
  padding-block: 8px 32px;
}

.page-about .about-hero__title {
  margin-block: 16px 20px;
  color: var(--c-white);
}

.page-about .about-hero__lede {
  max-width: 34em;
  color: var(--c-silver);
}

.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.page-about .about-hero__actions .btn {
  min-height: 44px;
  display: inline-flex;
  align-items: center;
}

.page-about .about-hero__panel {
  align-self: start;
  padding: 24px;
  background: linear-gradient(158deg, rgba(19, 90, 140, 0.28) 0%, rgba(22, 29, 37, 0.9) 46%, var(--c-steel) 100%);
  border: 1px solid var(--c-line);
  border-radius: 4px;
  box-shadow: var(--shadow-soft);
}

.page-about .about-panel__head {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--c-blue);
  padding-bottom: 14px;
  border-bottom: 1px solid var(--c-line);
}

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

.page-about .about-stats__item {
  display: flex;
  align-items: baseline;
  gap: 14px;
  padding-block: 14px;
  border-bottom: 1px dashed rgba(42, 52, 62, 0.9);
}

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

.page-about .about-stats__n {
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(30px, 5vw, 40px);
  line-height: 1;
  color: var(--c-white);
  letter-spacing: -0.01em;
  min-width: 3.2em;
}

.page-about .about-stats__n em {
  font-style: normal;
  font-size: 0.5em;
  margin-left: 2px;
  color: var(--c-silver);
}

.page-about .about-stats__l {
  font-size: 13px;
  letter-spacing: 0.06em;
  color: var(--c-silver);
}

.page-about .about-panel__note {
  margin-top: 16px;
  padding-top: 16px;
  border-top: 1px solid var(--c-line);
  font-size: 13px;
  line-height: 1.7;
  color: var(--c-dim);
}

/* ---------- 三个问题 ---------- */
.page-about .about-q {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--c-line);
}

.page-about .about-q__item {
  display: grid;
  grid-template-columns: 52px 1fr;
  gap: 16px;
  padding-block: 26px;
  border-bottom: 1px solid var(--c-line);
}

@media (min-width: 768px) {
  .page-about .about-q__item {
    grid-template-columns: 120px 1fr;
    gap: 32px;
    padding-block: 32px;
  }
}

.page-about .about-q__idx {
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.12em;
  color: var(--c-blue);
  padding-top: 4px;
}

.page-about .about-q__title {
  font-size: 18px;
  font-weight: 700;
  color: var(--c-white);
  margin-bottom: 8px;
}

.page-about .about-q__body p {
  font-size: 15px;
  line-height: 1.8;
  color: var(--c-silver);
  max-width: 36em;
}

.page-about .about-why__tail {
  margin-top: 32px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--c-silver);
}

.page-about .about-why__tail a {
  color: var(--c-blue);
  text-decoration: none;
  border-bottom: 1px solid rgba(79, 184, 255, 0.35);
}

.page-about .about-why__tail a:hover {
  border-bottom-color: var(--c-blue);
}

/* ---------- 斜切色带 ---------- */
.page-about .about-slant {
  height: 84px;
  background: linear-gradient(90deg, rgba(19, 90, 140, 0.55) 0%, rgba(79, 184, 255, 0.14) 48%, rgba(5, 7, 10, 0) 100%);
  clip-path: polygon(0 34%, 100% 0, 100% 66%, 0 100%);
}

.page-about .about-slant--flip {
  background: linear-gradient(270deg, rgba(19, 90, 140, 0.45) 0%, rgba(79, 184, 255, 0.1) 52%, rgba(5, 7, 10, 0) 100%);
  clip-path: polygon(0 0, 100% 34%, 100% 100%, 0 66%);
}

@media (min-width: 768px) {
  .page-about .about-slant {
    height: 120px;
  }
}

/* ---------- 时间线 ---------- */
.page-about .about-tl-intro {
  display: grid;
  gap: 20px;
  margin-bottom: var(--about-gap);
}

@media (min-width: 768px) {
  .page-about .about-tl-intro {
    grid-template-columns: 1fr 1fr;
    align-items: end;
    gap: 40px;
  }
}

.page-about .about-tl-figure {
  margin: 0;
}

.page-about .about-tl-intro__text {
  font-size: 15px;
  line-height: 1.85;
  color: var(--c-silver);
  max-width: 30em;
  border-left: 2px solid var(--c-blue);
  padding-left: 18px;
}

.page-about .about-tl {
  list-style: none;
  margin: 0;
  padding: 0 0 0 var(--tl-pad);
  position: relative;
}

.page-about .about-tl::before {
  content: "";
  position: absolute;
  left: 4px;
  top: 6px;
  bottom: 6px;
  width: 1px;
  background: var(--c-line);
}

.page-about .about-tl::after {
  content: "";
  position: absolute;
  left: 0;
  top: 0;
  bottom: 0;
  width: 12px;
  background: repeating-linear-gradient(to bottom, rgba(42, 52, 62, 0.85) 0 1px, transparent 1px 14px);
  pointer-events: none;
}

.page-about .about-tl-node {
  position: relative;
  padding-bottom: 48px;
}

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

.page-about .about-tl-node::before {
  content: "";
  position: absolute;
  left: calc(var(--tl-pad) * -1);
  top: 8px;
  width: 9px;
  height: 9px;
  border-radius: 50%;
  background: var(--c-steel);
  border: 1px solid var(--c-line);
  transition: background 320ms var(--ease), box-shadow 320ms var(--ease);
}

.page-about .about-tl-node.is-visible::before {
  background: var(--c-blue);
  border-color: var(--c-blue);
  box-shadow: 0 0 0 4px rgba(79, 184, 255, 0.16);
}

.page-about .about-tl-node__idx {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.14em;
  color: var(--c-dim);
  margin-bottom: 6px;
}

.page-about .about-tl-node__title {
  font-family: var(--font-display);
  font-size: clamp(22px, 3vw, 30px);
  font-weight: 800;
  line-height: 1.2;
  color: var(--c-white);
  margin-bottom: 10px;
}

.page-about .about-tl-node__text {
  font-size: 15px;
  line-height: 1.85;
  color: var(--c-silver);
  max-width: 36em;
}

.page-about .about-tl-node__more {
  margin-top: 14px;
  border-left: 1px solid var(--c-line);
  padding-left: 14px;
}

.page-about .about-tl-node__more summary {
  cursor: pointer;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--c-blue);
  min-height: 32px;
  display: flex;
  align-items: center;
  gap: 8px;
}

.page-about .about-tl-node__more summary::-webkit-details-marker {
  display: none;
}

.page-about .about-tl-node__more summary::before {
  content: "+";
  font-size: 14px;
  line-height: 1;
  color: var(--c-blue);
}

.page-about .about-tl-node__more[open] summary::before {
  content: "−";
}

.page-about .about-tl-node__more p {
  font-size: 14px;
  line-height: 1.8;
  color: var(--c-dim);
  padding-block: 6px 2px;
  max-width: 34em;
}

/* ---------- 团队 ---------- */
.page-about .about-team-figure {
  margin: 0 0 var(--about-gap);
}

.page-about .about-groups {
  border-top: 1px solid var(--c-line);
}

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

.page-about .about-group__sum {
  cursor: pointer;
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  align-items: baseline;
  gap: 10px 16px;
  padding-block: 20px;
  min-height: 44px;
}

.page-about .about-group__sum::-webkit-details-marker {
  display: none;
}

.page-about .about-group__idx {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.12em;
  color: var(--c-orange);
}

.page-about .about-group__name {
  font-size: 18px;
  font-weight: 700;
  color: var(--c-white);
}

.page-about .about-group__hint {
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--c-dim);
  margin-left: auto;
}

.page-about .about-group[open] .about-group__idx {
  color: var(--c-blue);
}

.page-about .about-group__body {
  padding: 0 0 26px;
  max-width: 52em;
}

.page-about .about-group__body p {
  font-size: 15px;
  line-height: 1.85;
  color: var(--c-silver);
  margin-bottom: 14px;
}

.page-about .about-group__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 8px;
}

.page-about .about-group__list li {
  position: relative;
  padding-left: 18px;
  font-size: 14px;
  line-height: 1.75;
  color: var(--c-dim);
}

.page-about .about-group__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.7em;
  width: 8px;
  height: 1px;
  background: var(--c-blue);
}

/* ---------- 节奏 ---------- */
.page-about .about-band {
  background: var(--c-carbon);
  border-top: 1px solid var(--c-line);
  border-bottom: 1px solid var(--c-line);
  padding-block: var(--about-pad);
}

.page-about .about-band__inner {
  display: block;
}

.page-about .about-rhythm {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 28px;
}

@media (min-width: 900px) {
  .page-about .about-rhythm {
    grid-template-columns: repeat(3, 1fr);
    gap: 40px;
  }
}

.page-about .about-rhythm__item {
  padding-top: 20px;
  border-top: 2px solid var(--c-line);
}

.page-about .about-rhythm__item:first-child {
  border-top-color: var(--c-blue);
}

.page-about .about-rhythm__n {
  display: block;
  font-family: var(--font-display);
  font-size: clamp(48px, 8vw, 76px);
  font-weight: 900;
  line-height: 0.9;
  letter-spacing: -0.02em;
  color: var(--c-white);
}

.page-about .about-rhythm__u {
  display: block;
  margin-top: 8px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.1em;
  color: var(--c-blue);
}

.page-about .about-rhythm__d {
  margin-top: 14px;
  font-size: 14px;
  line-height: 1.8;
  color: var(--c-silver);
}

.page-about .about-band__tail {
  margin-top: 36px;
  font-size: 15px;
  line-height: 1.8;
  color: var(--c-dim);
}

.page-about .about-band__tail a {
  color: var(--c-blue);
  text-decoration: none;
  border-bottom: 1px solid rgba(79, 184, 255, 0.35);
}

.page-about .about-band__tail a:hover {
  border-bottom-color: var(--c-blue);
}

/* ---------- 兼容 ---------- */
.page-about .about-compat__grid {
  align-items: start;
}

.page-about .about-compat__p {
  font-size: 15px;
  line-height: 1.85;
  color: var(--c-silver);
  margin-top: 18px;
  max-width: 36em;
}

.page-about .about-compat__p a {
  color: var(--c-blue);
  text-decoration: none;
  border-bottom: 1px solid rgba(79, 184, 255, 0.35);
}

.page-about .about-compat__list {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: grid;
  gap: 10px;
  max-width: 40em;
}

.page-about .about-compat__list li {
  position: relative;
  padding-left: 20px;
  font-size: 14px;
  line-height: 1.75;
  color: var(--c-silver);
}

.page-about .about-compat__list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.72em;
  width: 12px;
  height: 1px;
  background: var(--c-orange);
}

.page-about .about-compat__figure {
  margin: 32px 0 0;
}

@media (min-width: 768px) {
  .page-about .about-compat__figure {
    margin-top: 56px;
  }
}

/* ---------- 说话方式 ---------- */
.page-about .about-voice__cols {
  display: grid;
  gap: 32px;
}

@media (min-width: 900px) {
  .page-about .about-voice__cols {
    grid-template-columns: repeat(3, 1fr);
    gap: 48px;
  }
}

.page-about .about-voice__col {
  padding-left: 18px;
  border-left: 1px solid var(--c-line);
}

.page-about .about-voice__title {
  font-size: 17px;
  font-weight: 700;
  color: var(--c-white);
  margin-bottom: 10px;
}

.page-about .about-voice__col p {
  font-size: 14px;
  line-height: 1.85;
  color: var(--c-silver);
}

/* ---------- 收尾 ---------- */
.page-about .about-next {
  padding-bottom: calc(var(--about-pad) + 24px);
}

.page-about .about-next__box {
  position: relative;
  padding: 32px 24px;
  border: 1px solid var(--c-line);
  border-radius: 4px;
  background: linear-gradient(148deg, rgba(19, 90, 140, 0.22) 0%, rgba(12, 17, 22, 0.96) 62%);
  overflow: hidden;
}

.page-about .about-next__box::after {
  content: "";
  position: absolute;
  right: -60px;
  top: -60px;
  width: 180px;
  height: 180px;
  border: 1px solid rgba(79, 184, 255, 0.22);
  border-radius: 50%;
  pointer-events: none;
}

@media (min-width: 768px) {
  .page-about .about-next__box {
    padding: 48px;
  }
}

.page-about .about-next__p {
  margin-top: 18px;
  font-size: 15px;
  line-height: 1.85;
  color: var(--c-silver);
  max-width: 44em;
}

.page-about .about-next__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 28px;
}

.page-about .about-next__actions .btn {
  min-height: 44px;
  display: inline-flex;
  align-items: center;
}

.page-about a:focus-visible,
.page-about summary:focus-visible {
  outline: 2px solid var(--c-blue);
  outline-offset: 3px;
}

@media (prefers-reduced-motion: reduce) {
  .page-about .about-tl-node::before {
    background: var(--c-blue);
    border-color: var(--c-blue);
    transition: none;
  }
}
<<<END>>>