/* ============ 品牌历程 / page-about ============ */
.page-about {
  --pa-mark-w: 172px;
  --pa-gutter: 46px;
  --pa-bar: var(--bar-h, 72px);
  background: var(--paper);
  color: var(--ink);
}

/* ---------- 面包屑 ---------- */
.page-about .breadcrumb {
  padding-block: 22px 0;
  font-family: var(--mono);
  font-size: 12.5px;
  letter-spacing: 0.08em;
  color: var(--teal);
}
.page-about .breadcrumb a {
  color: var(--sky);
  text-decoration: none;
  border-bottom: 2px solid transparent;
}
.page-about .breadcrumb a:hover,
.page-about .breadcrumb a:focus-visible {
  border-bottom-color: var(--orange);
}
.page-about .breadcrumb span[aria-hidden] {
  padding-inline: 8px;
  color: var(--orange);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  padding-block: 26px 0;
  border-bottom: 3px solid var(--ink);
  background:
    linear-gradient(180deg, rgba(22, 104, 179, 0.06) 0%, rgba(246, 241, 231, 0) 58%),
    var(--paper);
}

.page-about .about-hero__inner {
  display: grid;
  gap: 18px;
  padding-bottom: 34px;
}

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

.page-about .about-hero__title {
  margin: 0;
  font-family: var(--display);
  font-weight: 900;
  font-size: clamp(36px, 8.4vw, 78px);
  line-height: 1.03;
  letter-spacing: 0.005em;
}

.page-about .about-hero__lede {
  border-left: 5px solid var(--orange);
  padding-left: 16px;
}
.page-about .about-hero__lede p {
  margin: 0 0 12px;
  font-size: 16.5px;
  line-height: 1.88;
  max-width: 40em;
}
.page-about .about-hero__lede p:last-child {
  margin-bottom: 0;
  color: var(--teal);
  font-weight: 500;
}

@media (min-width: 880px) {
  .page-about .about-hero__inner {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    grid-template-areas:
      "eyebrow eyebrow"
      "title   lede";
    column-gap: 56px;
    row-gap: 26px;
    align-items: end;
    padding-bottom: 48px;
  }
  .page-about .about-hero__eyebrow { grid-area: eyebrow; }
  .page-about .about-hero__title { grid-area: title; }
  .page-about .about-hero__lede {
    grid-area: lede;
    align-self: end;
    padding-bottom: 6px;
  }
  .page-about .about-hero__lede p { font-size: 17px; }
}

/* ---------- 起止刻度带 ---------- */
.page-about .about-span {
  display: flex;
  align-items: center;
  gap: 14px;
  padding-block: 16px 20px;
  font-size: 11.5px;
  letter-spacing: 0.14em;
  color: var(--teal);
  text-transform: uppercase;
}
.page-about .about-span__line {
  flex: 1 1 auto;
  height: 3px;
  background: linear-gradient(90deg, var(--sky) 0%, var(--orange) 100%);
}
.page-about .about-span__b { color: var(--orange); }

/* ---------- 时间轴 ---------- */
.page-about .about-track {
  padding-block: 48px 0;
}

.page-about .about-track__title {
  margin: 0 0 8px;
  font-family: var(--display);
  font-weight: 800;
  font-size: clamp(22px, 4.6vw, 34px);
  line-height: 1.25;
  letter-spacing: 0.01em;
}

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

.page-about .tl-item {
  display: grid;
  gap: 18px;
  padding-block: 42px;
  border-top: 3px solid var(--ink);
  scroll-margin-top: calc(var(--pa-bar) + 22px);
}
.page-about .tl-item:first-child { margin-top: 28px; }

.page-about .tl-mark {
  display: flex;
  align-items: baseline;
  gap: 12px;
  flex-wrap: wrap;
}

.page-about .tl-year {
  font-family: var(--mono);
  font-weight: 700;
  font-size: 30px;
  line-height: 1;
  letter-spacing: -0.035em;
  color: var(--sky);
}
.page-about .tl-year--deep { color: var(--orange-lt); }

.page-about .tl-phase {
  font-family: var(--mono);
  font-size: 11.5px;
  letter-spacing: 0.16em;
  text-transform: uppercase;
  padding: 4px 9px;
  border: 2px solid var(--ink);
  background: var(--paper-2);
  color: var(--ink);
  white-space: nowrap;
}
.page-about .tl-phase--deep {
  border-color: var(--snow);
  background: var(--orange);
  color: var(--ink);
}

.page-about .tl-title {
  margin: 0 0 14px;
  font-family: var(--display);
  font-weight: 800;
  font-size: clamp(23px, 4.6vw, 34px);
  line-height: 1.22;
  letter-spacing: 0.008em;
}

.page-about .tl-body p {
  margin: 0 0 14px;
  font-size: 16.5px;
  line-height: 1.88;
}
.page-about .tl-body p:last-child { margin-bottom: 0; }

.page-about .tl-list {
  list-style: none;
  margin: 0 0 18px;
  padding: 0;
  display: grid;
  gap: 11px;
  max-width: 56ch;
}
.page-about .tl-list li {
  position: relative;
  padding-left: 24px;
  font-size: 16px;
  line-height: 1.78;
}
.page-about .tl-list li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 0.6em;
  width: 10px;
  height: 10px;
  background: var(--orange);
  border: 2px solid var(--ink);
}

/* 深色架构面板 */
.page-about .tl-item--deep .tl-body {
  background: var(--teal);
  color: var(--snow);
  border: var(--edge);
  box-shadow: var(--shadow-hard);
  padding: 26px 20px;
}
.page-about .tl-item--deep .tl-title { color: var(--snow); }
.page-about .tl-item--deep .tl-body p { color: rgba(253, 252, 249, 0.9); }
.page-about .tl-item--deep .tl-list li { color: rgba(253, 252, 249, 0.9); }
.page-about .tl-item--deep .tl-list li::before {
  border-color: var(--snow);
  background: var(--orange-lt);
}
.page-about .tl-item--deep .media { border-color: var(--snow); }
.page-about .tl-item--deep .media__caption { color: rgba(253, 252, 249, 0.72); }

@media (min-width: 900px) {
  .page-about .tl-item {
    grid-template-columns: var(--pa-mark-w) minmax(0, 1fr);
    column-gap: var(--pa-gutter);
  }
  .page-about .tl-item:nth-child(1) { padding-block: 52px 68px; }
  .page-about .tl-item:nth-child(2) { padding-block: 68px 84px; }
  .page-about .tl-item:nth-child(3) { padding-block: 84px 96px; }
  .page-about .tl-item:nth-child(4) { padding-block: 92px 104px; }
  .page-about .tl-item:nth-child(5) { padding-block: 100px 110px; }
  .page-about .tl-item:nth-child(6) { padding-block: 108px 40px; }

  .page-about .tl-mark {
    flex-direction: column;
    align-items: flex-start;
    gap: 10px;
    align-self: start;
    position: sticky;
    top: calc(var(--pa-bar) + 20px);
  }
  .page-about .tl-year { font-size: 42px; }

  .page-about .tl-item:nth-child(1) .tl-body { max-width: 60ch; }
  .page-about .tl-item:nth-child(2) .tl-body { max-width: 62ch; }
  .page-about .tl-item:nth-child(3) .tl-body { max-width: 56ch; }
  .page-about .tl-item:nth-child(4) .tl-body { max-width: 50ch; }
  .page-about .tl-item:nth-child(5) .tl-body { max-width: 46ch; }
  .page-about .tl-item:nth-child(6) .tl-body { max-width: 44ch; }

  .page-about .tl-item--deep .tl-body { padding: 36px 34px; }
}

/* ---------- 图片 ---------- */
.page-about .about-fig {
  margin: 22px 0 6px;
}
.page-about .about-fig .media { margin: 0; }
.page-about .about-fig .media img {
  display: block;
  width: 100%;
  height: auto;
  object-fit: cover;
}
.page-about .about-fig .media--wide img { aspect-ratio: 14 / 9; }
.page-about .about-fig .media--tall img { aspect-ratio: 4 / 3; }
.page-about .media__caption {
  display: block;
  margin-top: 10px;
  font-size: 13.5px;
  line-height: 1.7;
  letter-spacing: 0.01em;
  color: var(--teal);
}

/* ---------- SVG 折线图 ---------- */
.page-about .about-chart {
  margin: 26px 0 8px;
}
.page-about .about-chart svg {
  display: block;
  width: 100%;
  height: auto;
}
.page-about .about-chart__axis line {
  stroke: rgba(253, 252, 249, 0.34);
  stroke-width: 2;
}
.page-about .about-chart__nodes {
  fill: none;
  stroke: var(--orange-lt);
  stroke-width: 4;
  stroke-linecap: round;
  stroke-linejoin: round;
}
.page-about .about-chart__load {
  fill: none;
  stroke: var(--snow);
  stroke-width: 3;
  stroke-dasharray: 9 7;
  stroke-linecap: round;
  stroke-linejoin: round;
}
.page-about .about-chart__dots circle {
  fill: var(--orange);
  stroke: var(--snow);
  stroke-width: 2.5;
}
.page-about .about-chart__label text,
.page-about .about-chart__note text {
  fill: rgba(253, 252, 249, 0.82);
  font-family: var(--mono);
  font-size: 13px;
  letter-spacing: 0.04em;
}
.page-about .about-chart__note text { fill: var(--orange-lt); }
.page-about .about-chart__cap {
  display: block;
  margin-top: 12px;
  font-size: 14px;
  line-height: 1.72;
  color: rgba(253, 252, 249, 0.76);
}

/* ---------- 版本索引与版本清单 ---------- */
.page-about .ver-rail {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  margin: 8px 0 26px;
}
.page-about .ver-chip {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 12px;
  border: 2px solid var(--ink);
  background: var(--snow);
  color: var(--ink);
  text-decoration: none;
  font-size: 13px;
  line-height: 1;
  box-shadow: 3px 3px 0 var(--ink);
  transition: transform 0.14s ease, box-shadow 0.14s ease, background-color 0.14s ease;
}
.page-about .ver-chip:hover,
.page-about .ver-chip:focus-visible {
  transform: translate(-2px, -2px);
  box-shadow: 5px 5px 0 var(--ink);
  background: var(--paper-2);
}
.page-about .ver-chip:focus-visible {
  outline: 3px solid var(--sky);
  outline-offset: 2px;
}
.page-about .ver-chip__label {
  font-size: 12px;
  color: var(--teal);
}
.page-about .ver-chip--now {
  background: var(--orange);
  border-color: var(--ink);
  font-weight: 700;
}
.page-about .ver-chip--now .ver-chip__label { color: var(--ink); }

.page-about .ver-list {
  list-style: none;
  margin: 0;
  padding: 0;
  border-top: 2px solid var(--ink);
}
.page-about .ver-row {
  display: grid;
  gap: 6px;
  padding: 18px 0;
  border-bottom: 2px solid var(--ink);
  scroll-margin-top: calc(var(--pa-bar) + 24px);
}
.page-about .ver-row:target {
  background: var(--paper-2);
  box-shadow: inset 5px 0 0 var(--orange);
  outline: 3px solid var(--orange);
  outline-offset: 3px;
  padding-inline: 12px;
}
.page-about .ver-num {
  font-size: 18px;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--sky);
}
.page-about .ver-row--now .ver-num { color: var(--orange); }
.page-about .ver-name {
  margin: 0 0 4px;
  font-family: var(--display);
  font-size: 17px;
  font-weight: 800;
  line-height: 1.4;
}
.page-about .ver-text p {
  margin: 0;
  font-size: 15.5px;
  line-height: 1.8;
}

@media (min-width: 760px) {
  .page-about .ver-row {
    grid-template-columns: 132px minmax(0, 1fr);
    gap: 24px;
    align-items: baseline;
    padding: 22px 0;
  }
  .page-about .ver-num { font-size: 20px; }
}

/* ---------- 折叠面板 ---------- */
.page-about .about-fold {
  margin-top: 24px;
  border: 2px solid var(--ink);
  background: var(--paper-2);
  box-shadow: 4px 4px 0 var(--ink);
}
.page-about .about-fold > summary {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 14px 18px;
  cursor: pointer;
  font-weight: 700;
  font-size: 15px;
  list-style: none;
}
.page-about .about-fold > summary::-webkit-details-marker { display: none; }
.page-about .about-fold > summary::before {
  content: "+";
  flex: none;
  display: grid;
  place-items: center;
  width: 22px;
  height: 22px;
  background: var(--ink);
  color: var(--paper);
  font-family: var(--mono);
  font-size: 16px;
  line-height: 1;
}
.page-about .about-fold[open] > summary::before { content: "−"; }
.page-about .about-fold > summary:focus-visible {
  outline: 3px solid var(--orange);
  outline-offset: -3px;
}
.page-about .about-fold__body {
  padding: 2px 18px 18px;
}
.page-about .about-fold__body p {
  margin: 0 0 14px;
  font-size: 15.5px;
  line-height: 1.82;
}
.page-about .about-fold__body .tl-list { margin-bottom: 0; }
.page-about .about-fold__body .tl-list li { font-size: 15px; }

/* ---------- 下一步 ---------- */
.page-about .about-next {
  margin-top: 56px;
  padding-block: 46px 58px;
  background: var(--paper-2);
  border-top: 3px solid var(--ink);
}
.page-about .about-next__title {
  margin: 10px 0 26px;
  font-family: var(--display);
  font-weight: 800;
  font-size: clamp(21px, 4.2vw, 30px);
  line-height: 1.28;
}
.page-about .about-next__list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 14px;
}
.page-about .about-next__list a {
  display: grid;
  grid-template-columns: auto minmax(0, 1fr);
  grid-template-areas:
    "idx name"
    "idx desc";
  column-gap: 14px;
  row-gap: 6px;
  align-items: start;
  padding: 18px 18px 20px;
  background: var(--snow);
  border: 2px solid var(--ink);
  box-shadow: 4px 4px 0 var(--ink);
  text-decoration: none;
  color: var(--ink);
  transition: transform 0.15s ease, box-shadow 0.15s ease;
}
.page-about .about-next__list a:hover,
.page-about .about-next__list a:focus-visible {
  transform: translate(-2px, -2px);
  box-shadow: 7px 7px 0 var(--ink);
}
.page-about .about-next__list a:focus-visible {
  outline: 3px solid var(--orange);
  outline-offset: 2px;
}
.page-about .about-next__idx {
  grid-area: idx;
  font-size: 13px;
  font-weight: 700;
  color: var(--orange);
  padding-top: 3px;
}
.page-about .about-next__name {
  grid-area: name;
  font-family: var(--display);
  font-size: 17px;
  font-weight: 800;
  line-height: 1.35;
}
.page-about .about-next__desc {
  grid-area: desc;
  font-size: 14.5px;
  line-height: 1.75;
  color: var(--teal);
}

@media (min-width: 780px) {
  .page-about .about-next__list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 20px;
  }
}

@media (max-width: 400px) {
  .page-about .ver-chip { padding: 7px 9px; font-size: 12px; }
  .page-about .tl-year { font-size: 26px; }
  .page-about .about-hero__lede { padding-left: 13px; }
}
<<<END>>>