/* ============ 品牌历程 / page-about ============ */
.page-about {
  display: block;
  padding-bottom: clamp(2.5rem, 6vw, 4.5rem);
}

.page-about .about-crumbs {
  padding-top: clamp(1rem, 3vw, 1.75rem);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding-top: clamp(1.25rem, 3.5vw, 2.5rem);
}

.page-about .about-hero__grid {
  display: grid;
  gap: clamp(1.5rem, 4vw, 3rem);
}

.page-about .about-eyebrow {
  display: inline-flex;
  align-items: center;
  gap: .55rem;
  margin: 0 0 .9rem;
  font-family: var(--font-mono);
  font-size: .75rem;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--c-mist);
}

.page-about .about-eyebrow::before {
  content: "";
  width: 26px;
  height: 1px;
  background: var(--c-cyan);
}

.page-about h1 {
  margin: 0 0 1rem;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(1.85rem, 5.2vw, 3.4rem);
  line-height: 1.16;
  letter-spacing: -.02em;
}

.page-about .about-hero__text {
  margin: 0;
  max-width: 46ch;
  font-size: clamp(1rem, 1.3vw, 1.125rem);
  line-height: 1.85;
  color: var(--c-ink);
}

.page-about .about-hero__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: .75rem;
}

@media (min-width: 900px) {
  .page-about .about-hero__grid {
    grid-template-columns: 7fr 5fr;
    align-items: end;
  }
}

.page-about .about-banner {
  margin: clamp(1.75rem, 4vw, 3rem) 0 0;
}

/* ---------- 档案区块通用骨架 ---------- */
.page-about .archive-block {
  margin-top: clamp(2rem, 5vw, 3.25rem);
  scroll-margin-top: 6.5rem;
}

.page-about .archive-row {
  display: grid;
  gap: 1rem;
  padding: clamp(1.25rem, 3vw, 2.25rem) 0;
  border-top: 1px solid var(--c-line);
}

.page-about .archive-id {
  display: flex;
  align-items: baseline;
  gap: .7rem;
}

.page-about .archive-id__code {
  font-family: var(--font-mono);
  font-size: 1.35rem;
  font-weight: 700;
  font-variant-numeric: tabular-nums;
  letter-spacing: .06em;
  color: var(--c-mist);
}

.page-about .archive-id__label {
  font-family: var(--font-mono);
  font-size: .75rem;
  letter-spacing: .1em;
  color: var(--c-cyan);
}

@media (min-width: 900px) {
  .page-about .archive-row {
    grid-template-columns: 3fr 9fr;
    gap: clamp(1.5rem, 4vw, 3rem);
  }

  .page-about .archive-id {
    position: sticky;
    top: 6rem;
    align-self: start;
    flex-direction: column;
    gap: .4rem;
  }
}

.page-about .archive-body h2 {
  margin: 0 0 .9rem;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(1.35rem, 2.6vw, 2rem);
  line-height: 1.3;
  letter-spacing: -.01em;
}

.page-about .archive-lead {
  margin: 0 0 1.25rem;
  max-width: 62ch;
  font-size: .9375rem;
  line-height: 1.85;
  color: var(--c-mist);
}

.page-about .archive-note {
  margin: 1.25rem 0 0;
  max-width: 66ch;
  padding-left: 1rem;
  border-left: 2px solid var(--c-line);
  font-size: .875rem;
  line-height: 1.85;
  color: var(--c-mist);
}

.page-about .archive-body .prose a,
.page-about .version-item p a,
.page-about .about-zone__foot a {
  color: var(--c-cyan);
  text-decoration: underline;
  text-underline-offset: 3px;
}

/* ---------- P-01 事实行 ---------- */
.page-about .about-facts {
  display: grid;
  gap: 0;
  margin: 1.5rem 0 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--c-line);
}

.page-about .about-facts li {
  display: grid;
  gap: .3rem;
  padding: .85rem 0;
  border-bottom: 1px solid var(--c-line);
}

.page-about .about-facts__k {
  font-family: var(--font-mono);
  font-size: .75rem;
  letter-spacing: .1em;
  color: var(--c-mist);
}

.page-about .about-facts__v {
  font-size: .9375rem;
  line-height: 1.75;
  color: var(--c-ink);
}

@media (min-width: 640px) {
  .page-about .about-facts li {
    grid-template-columns: 11rem 1fr;
    gap: 1.25rem;
    align-items: baseline;
  }
}

/* ---------- P-02 版本时间轴 ---------- */
.page-about .timeline {
  margin: 0 0 1.75rem;
}

.page-about .timeline__track {
  position: relative;
}

.page-about .timeline__line {
  display: none;
  position: absolute;
  left: 0;
  top: 1.9rem;
  width: 100%;
  min-width: 780px;
  height: 34px;
  pointer-events: none;
  opacity: .55;
}

.page-about .timeline__line polyline {
  fill: none;
  stroke: var(--c-line);
  stroke-width: 1.5;
  stroke-dasharray: 7 9;
  vector-effect: non-scaling-stroke;
}

.page-about .timeline__nodes {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: .75rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .timeline__nodes > li {
  min-width: 0;
}

@media (min-width: 760px) {
  .page-about .timeline__line {
    display: block;
  }

  .page-about .timeline__track {
    overflow-x: auto;
    overflow-y: hidden;
    padding-bottom: .6rem;
    scrollbar-width: thin;
  }

  .page-about .timeline__nodes {
    flex-direction: row;
    gap: 1rem;
    min-width: 780px;
    padding-top: 1.6rem;
  }

  .page-about .timeline__nodes > li {
    flex: 1 1 0;
    min-width: 180px;
  }
}

.page-about .tl-node {
  position: relative;
  display: flex;
  flex-direction: column;
  gap: .3rem;
  height: 100%;
  padding: 1.15rem 1rem 1.25rem;
  background: var(--c-void-raise);
  border: 1px solid var(--c-line);
  color: var(--c-ink);
  text-decoration: none;
  transition: border-color .25s ease, transform .25s ease;
}

.page-about .tl-node__id {
  font-family: var(--font-mono);
  font-size: .8125rem;
  letter-spacing: .12em;
  color: var(--c-cyan);
}

.page-about .tl-node__name {
  font-size: 1.0625rem;
  font-weight: 700;
  letter-spacing: -.01em;
}

.page-about .tl-node__meta {
  font-size: .8125rem;
  line-height: 1.7;
  color: var(--c-mist);
}

.page-about .tl-node--key {
  background: linear-gradient(155deg, rgba(123, 91, 255, .26), var(--c-void-raise) 62%);
  border-color: var(--c-violet);
}

.page-about .tl-node--key .tl-node__id {
  color: var(--c-violet-soft);
}

@media (min-width: 760px) {
  .page-about .tl-node::before {
    content: "";
    position: absolute;
    top: -0.4rem;
    left: .9rem;
    width: 9px;
    height: 9px;
    border-radius: 50%;
    background: var(--c-cyan);
    box-shadow: 0 0 0 3px var(--c-void-raise);
  }

  .page-about .tl-node--key::before {
    top: -0.55rem;
    width: 13px;
    height: 13px;
    background: var(--c-violet);
  }

  .page-about .tl-node:hover,
  .page-about .tl-node:focus-visible {
    border-color: var(--c-cyan);
    transform: translateY(-3px);
  }
}

/* ---------- P-02 版本条目 ---------- */
.page-about .version-list {
  display: grid;
  gap: .9rem;
  margin: 0 0 1.5rem;
  padding: 0;
  list-style: none;
}

.page-about .version-item {
  padding: clamp(1rem, 2.4vw, 1.5rem) clamp(1rem, 2.4vw, 1.6rem);
  background: var(--c-steel);
  border: 1px solid var(--c-line);
  clip-path: polygon(0 0, calc(100% - 16px) 0, 100% 16px, 100% 100%, 0 100%);
  scroll-margin-top: 6.5rem;
  transition: border-color .25s ease;
}

.page-about .version-item:hover {
  border-color: var(--c-cyan);
}

.page-about .version-item__id {
  display: block;
  margin-bottom: .5rem;
  font-family: var(--font-mono);
  font-size: .8125rem;
  letter-spacing: .12em;
  color: var(--c-mist);
}

.page-about .version-item:hover .version-item__id {
  color: var(--c-cyan);
}

.page-about .version-item h3 {
  margin: 0 0 .5rem;
  font-family: var(--font-head);
  font-weight: 800;
  font-size: 1.0625rem;
  line-height: 1.5;
  letter-spacing: -.01em;
}

.page-about .version-item p {
  margin: 0;
  max-width: 68ch;
  font-size: .9375rem;
  line-height: 1.85;
  color: var(--c-ink);
}

.page-about .about-figure {
  margin: 1.75rem 0 0;
}

.page-about .about-figure--tight {
  margin-top: 1.5rem;
}

/* ---------- P-03 深蓝绿分区 ---------- */
.page-about .about-zone {
  padding: clamp(1.5rem, 4vw, 2.75rem);
  scroll-margin-top: 6.5rem;
}

.page-about .about-zone__head {
  max-width: 62ch;
  margin-bottom: 1.5rem;
}

.page-about .about-zone__head .archive-id__code {
  display: block;
  margin-bottom: .6rem;
}

.page-about .about-zone h2 {
  margin: 0 0 .8rem;
  font-family: var(--font-head);
  font-weight: 900;
  font-size: clamp(1.35rem, 2.6vw, 2rem);
  line-height: 1.3;
  letter-spacing: -.01em;
}

.page-about .about-zone__body {
  display: grid;
  gap: clamp(1.5rem, 3.5vw, 2.5rem);
}

@media (min-width: 900px) {
  .page-about .about-zone__body {
    grid-template-columns: 7fr 5fr;
    align-items: start;
  }
}

.page-about .about-zone__foot {
  margin: 1.5rem 0 0;
  padding-top: 1.25rem;
  border-top: 1px solid rgba(255, 162, 58, .35);
  font-size: .9375rem;
  line-height: 1.85;
  color: var(--c-ink);
}

.page-about .about-zone__foot a {
  color: var(--c-amber);
}

.page-about .flow-steps {
  counter-reset: step;
  display: grid;
  gap: 1.1rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .flow-steps > li {
  position: relative;
  padding-left: 3rem;
  font-size: .9375rem;
  line-height: 1.8;
  color: var(--c-ink);
}

.page-about .flow-steps > li::before {
  counter-increment: step;
  content: counter(step, decimal-leading-zero);
  position: absolute;
  left: 0;
  top: .12rem;
  font-family: var(--font-mono);
  font-size: .8125rem;
  letter-spacing: .06em;
  color: var(--c-amber);
}

.page-about .flow-steps strong {
  display: block;
  margin-bottom: .2rem;
  font-weight: 700;
  color: var(--c-ink);
}

/* ---------- P-04 角色列表 ---------- */
.page-about .role-list {
  display: grid;
  gap: 0;
  margin: 0;
  padding: 0;
  list-style: none;
  border-top: 1px solid var(--c-line);
}

.page-about .role-list > li {
  display: grid;
  gap: .4rem;
  padding: 1.1rem 0;
  border-bottom: 1px solid var(--c-line);
}

.page-about .role-list__name {
  font-family: var(--font-mono);
  font-size: .875rem;
  letter-spacing: .08em;
  color: var(--c-cyan);
}

.page-about .role-list__text {
  margin: 0;
  font-size: .9375rem;
  line-height: 1.85;
  color: var(--c-ink);
}

@media (min-width: 720px) {
  .page-about .role-list > li {
    grid-template-columns: 9rem 1fr;
    gap: 1.25rem;
    align-items: start;
  }
}

/* ---------- P-05 规格表 ---------- */
.page-about .about-split {
  gap: clamp(1.5rem, 4vw, 2.5rem);
}

.page-about .about-spec {
  display: grid;
  gap: 0;
  margin: 0;
  border-top: 1px solid var(--c-line);
}

.page-about .about-spec__row {
  display: grid;
  gap: .2rem;
  padding: .85rem 0;
  border-bottom: 1px solid var(--c-line);
}

.page-about .about-spec dt {
  font-family: var(--font-mono);
  font-size: .8125rem;
  letter-spacing: .06em;
  color: var(--c-mist);
}

.page-about .about-spec dd {
  margin: 0;
  font-size: .9375rem;
  line-height: 1.75;
  color: var(--c-ink);
}

@media (min-width: 480px) {
  .page-about .about-spec__row {
    grid-template-columns: 7.5rem 1fr;
    gap: .75rem;
    align-items: baseline;
  }
}

/* ---------- P-06 纠错通道 ---------- */
.page-about .report-list {
  display: grid;
  gap: .7rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .report-list > li {
  position: relative;
  padding-left: 1.5rem;
  font-size: .9375rem;
  line-height: 1.8;
  color: var(--c-ink);
}

.page-about .report-list > li::before {
  content: "";
  position: absolute;
  left: 0;
  top: .72rem;
  width: 10px;
  height: 1px;
  background: var(--c-amber);
}

.page-about .about-callout {
  padding: clamp(1.1rem, 2.5vw, 1.6rem);
  background: var(--c-void-raise);
  border: 1px solid var(--c-line);
  clip-path: polygon(0 0, calc(100% - 16px) 0, 100% 16px, 100% 100%, 0 100%);
}

.page-about .about-callout p {
  margin: 0 0 1rem;
  font-size: .9375rem;
  line-height: 1.85;
  color: var(--c-ink);
}

.page-about .about-callout .btn {
  text-decoration: none;
}

/* ---------- 页尾继续查阅 ---------- */
.page-about .about-next {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: .75rem 1rem;
  margin-top: clamp(2rem, 5vw, 3.25rem);
  padding-top: 1.5rem;
  border-top: 1px solid var(--c-line);
}

.page-about .about-next__label {
  font-family: var(--font-mono);
  font-size: .75rem;
  letter-spacing: .14em;
  text-transform: uppercase;
  color: var(--c-mist);
}

.page-about .about-next__list {
  display: flex;
  flex-wrap: wrap;
  gap: .5rem .75rem;
  margin: 0;
  padding: 0;
  list-style: none;
}

.page-about .about-next__list a {
  display: inline-block;
  padding: .45rem .85rem;
  border: 1px solid var(--c-line);
  font-size: .875rem;
  color: var(--c-ink);
  text-decoration: none;
  transition: border-color .2s ease, color .2s ease;
}

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

/* ---------- 降低动效偏好 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .tl-node,
  .page-about .version-item,
  .page-about .about-next__list a {
    transition: none;
  }

  .page-about .tl-node:hover,
  .page-about .tl-node:focus-visible {
    transform: none;
  }
}