.page-about {
  --about-rail-w: 208px;
  --about-note-w: 252px;
  --about-shift: 40px;
  background: var(--ink-900);
  color: var(--paper);
}

/* ── 顶部斜向切片 ── */
.page-about .about-slash {
  height: 12px;
  background: linear-gradient(102deg, var(--flame) 0%, var(--flame-deep) 34%, var(--copper) 62%, rgba(192, 138, 78, 0) 100%);
  clip-path: polygon(0 0, 100% 0, 100% 40%, 0 100%);
}

/* ── 首屏 ── */
.page-about .about-hero {
  position: relative;
  padding: clamp(28px, 4vw, 52px) 0 clamp(34px, 4.6vw, 60px);
  border-bottom: 1px solid var(--line-soft);
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  inset: 0;
  background: repeating-linear-gradient(112deg, rgba(232, 235, 230, .035) 0 1px, transparent 1px 15px);
  pointer-events: none;
}

.page-about .about-hero > .container {
  position: relative;
  z-index: 1;
}

.page-about .about-hero-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(24px, 3.4vw, 40px);
  margin-top: clamp(22px, 3vw, 34px);
  align-items: end;
}

@media (min-width: 900px) {
  .page-about .about-hero-grid {
    grid-template-columns: minmax(0, 1fr) 244px;
  }
}

.page-about .about-kicker {
  margin: 0 0 16px;
  font-family: var(--font-num);
  font-size: 12px;
  letter-spacing: .2em;
  color: var(--copper);
}

.page-about .about-title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(31px, 4.4vw, 56px);
  line-height: 1.16;
  letter-spacing: .045em;
}

.page-about .about-lead {
  max-width: 680px;
  margin: 20px 0 0;
  font-size: clamp(15.5px, 1.06vw, 17.5px);
  line-height: 1.88;
  color: rgba(232, 235, 230, .88);
}

.page-about .about-hero-mark {
  border-left: 2px solid var(--copper-soft);
  padding-left: 18px;
}

.page-about .about-hero-num {
  display: block;
  font-family: var(--font-num);
  font-weight: 700;
  font-size: clamp(54px, 8vw, 92px);
  line-height: .9;
  letter-spacing: .01em;
  color: var(--flame);
}

.page-about .about-hero-mark-label {
  display: block;
  margin-top: 10px;
  font-size: 12.5px;
  line-height: 1.6;
  color: var(--mid);
}

.page-about .about-hero-facts {
  list-style: none;
  margin: clamp(28px, 3.4vw, 42px) 0 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px clamp(14px, 2.6vw, 30px);
}

@media (min-width: 760px) {
  .page-about .about-hero-facts {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}

.page-about .about-fact {
  border-top: 1px solid var(--copper-soft);
  padding-top: 12px;
  min-width: 0;
}

.page-about .about-fact-num {
  display: block;
  font-family: var(--font-num);
  font-weight: 700;
  font-size: clamp(23px, 2.5vw, 31px);
  line-height: 1.1;
  color: var(--paper);
}

.page-about .about-fact-label {
  display: block;
  margin-top: 6px;
  font-size: 12.5px;
  line-height: 1.55;
  color: var(--mid);
}

/* ── 主体双栏骨架 ── */
.page-about .about-body {
  padding: clamp(38px, 4.6vw, 68px) 0 clamp(60px, 7vw, 112px);
}

.page-about .about-layout {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(26px, 4vw, 56px);
}

@media (min-width: 1000px) {
  .page-about .about-layout {
    grid-template-columns: var(--about-rail-w) minmax(0, 1fr);
    gap: clamp(32px, 4vw, 64px);
    align-items: start;
  }
}

/* ── 左侧章节目录 ── */
.page-about .about-rail {
  min-width: 0;
}

@media (min-width: 1000px) {
  .page-about .about-rail {
    position: sticky;
    top: 96px;
    max-height: calc(100vh - 132px);
    overflow-y: auto;
  }
}

.page-about .about-rail-title {
  margin: 0 0 14px;
  font-family: var(--font-num);
  font-size: 11px;
  letter-spacing: .2em;
  color: var(--mid);
  text-transform: uppercase;
}

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

.page-about .about-rail-link {
  display: flex;
  align-items: baseline;
  gap: 9px;
  padding: 7px 0 7px 14px;
  border-left: 2px solid var(--line-soft);
  font-size: 14px;
  line-height: 1.5;
  color: var(--mid);
  text-decoration: none;
  transition: color var(--dur) var(--ease), border-color var(--dur) var(--ease);
}

.page-about .about-rail-num {
  font-family: var(--font-num);
  font-size: 11.5px;
  letter-spacing: .08em;
  color: var(--copper);
  transition: color var(--dur) var(--ease);
}

.page-about .about-rail-link:hover {
  color: var(--paper);
}

.page-about .about-rail-link[aria-current="true"] {
  color: var(--flame);
  border-left-color: var(--flame);
}

.page-about .about-rail-link[aria-current="true"] .about-rail-num {
  color: var(--flame);
}

@media (max-width: 999px) {
  .page-about .about-rail-list {
    display: flex;
    gap: 8px;
    overflow-x: auto;
    padding: 2px 2px 10px;
    scrollbar-width: thin;
  }

  .page-about .about-rail-item {
    flex: 0 0 auto;
  }

  .page-about .about-rail-link {
    border: 1px solid var(--line-soft);
    border-radius: var(--radius-pill);
    padding: 8px 16px;
    white-space: nowrap;
    background: var(--ink-800);
  }
}

/* ── 章节 ── */
.page-about .about-sec + .about-sec {
  margin-top: clamp(52px, 6vw, 92px);
  padding-top: clamp(40px, 5vw, 72px);
  border-top: 1px solid var(--line-soft);
}

.page-about .about-sec-head {
  display: flex;
  align-items: baseline;
  flex-wrap: wrap;
  gap: 6px 18px;
  margin-bottom: clamp(20px, 2.6vw, 34px);
}

.page-about .about-sec-index {
  font-family: var(--font-num);
  font-weight: 700;
  font-size: clamp(38px, 5vw, 68px);
  line-height: .95;
  letter-spacing: .01em;
  color: var(--copper);
}

.page-about .about-sec-title {
  margin: 0;
  font-family: var(--font-display);
  font-weight: 900;
  font-size: clamp(22px, 2.6vw, 32px);
  line-height: 1.28;
  letter-spacing: .05em;
}

.page-about .about-grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: clamp(22px, 3vw, 38px);
}

@media (min-width: 860px) {
  .page-about .about-grid {
    grid-template-columns: minmax(0, 1fr) var(--about-note-w);
    align-items: start;
  }

  .page-about .about-grid--visual {
    grid-template-columns: minmax(0, 1fr) minmax(200px, 260px);
  }
}

.page-about .about-main {
  min-width: 0;
}

.page-about .about-main > p {
  max-width: 720px;
  margin: 0 0 18px;
  font-size: clamp(15.5px, 1.04vw, 17px);
  line-height: 1.88;
  color: rgba(232, 235, 230, .86);
}

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

/* ── 右侧注记列 ── */
.page-about .about-notes {
  display: grid;
  gap: 22px;
  min-width: 0;
}

@media (min-width: 860px) {
  .page-about .about-notes {
    padding-top: var(--about-shift);
  }
}

.page-about .about-note {
  border-left: 2px solid var(--copper-soft);
  padding: 2px 0 2px 15px;
}

.page-about .about-note-label {
  display: block;
  margin-bottom: 6px;
  font-family: var(--font-num);
  font-size: 11.5px;
  letter-spacing: .16em;
  text-transform: uppercase;
  color: var(--copper);
}

.page-about .about-note-text {
  margin: 0;
  font-size: 13.5px;
  line-height: 1.75;
  color: var(--mid);
}

.page-about .about-inline-link {
  color: var(--flame);
  text-decoration: none;
  border-bottom: 1px solid var(--flame-soft);
  transition: border-color var(--dur) var(--ease);
}

.page-about .about-inline-link:hover {
  border-bottom-color: var(--flame);
}

/* ── 图片 ── */
.page-about .about-figure {
  margin: 26px 0;
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-lg);
  overflow: hidden;
  background: var(--ink-800);
}

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

.page-about .about-figure .media-caption {
  padding: 11px 15px;
  font-family: var(--font-num);
  font-size: 12px;
  letter-spacing: .02em;
  line-height: 1.6;
  color: var(--mid);
  background: var(--ink-800);
  border-top: 1px solid var(--line-soft);
}

/* ── 三条业务线 ── */
.page-about .about-lines {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .about-line {
  display: grid;
  grid-template-columns: 40px minmax(0, 1fr);
  gap: 4px 18px;
  padding: 26px 0;
  border-bottom: 1px solid var(--line-soft);
}

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

.page-about .about-line-num {
  font-family: var(--font-num);
  font-weight: 700;
  font-size: 18px;
  line-height: 1.6;
  color: var(--flame);
}

.page-about .about-line-body {
  min-width: 0;
}

.page-about .about-line-title {
  margin: 0 0 8px;
  font-size: 19px;
  font-weight: 700;
  letter-spacing: .04em;
  color: var(--paper);
}

.page-about .about-line-text {
  margin: 0 0 10px;
  font-size: 15px;
  line-height: 1.82;
  color: rgba(232, 235, 230, .82);
}

.page-about .about-line-for {
  margin: 0;
  font-family: var(--font-num);
  font-size: 12.5px;
  line-height: 1.6;
  letter-spacing: .03em;
  color: var(--copper);
}

/* ── 团队数字 ── */
.page-about .about-team {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.page-about .about-team-item {
  border: 1px solid var(--line-soft);
  border-radius: var(--radius-md);
  padding: 14px 14px 12px;
  background: var(--ink-800);
  min-width: 0;
}

.page-about .about-team-num {
  display: block;
  font-family: var(--font-num);
  font-weight: 700;
  font-size: 25px;
  line-height: 1.1;
  color: var(--flame);
}

.page-about .about-team-label {
  display: block;
  margin-top: 5px;
  font-size: 12.5px;
  line-height: 1.5;
  color: var(--mid);
}

/* ── 归档流程 ── */
.page-about .about-flow {
  list-style: none;
  margin: 26px 0 0;
  padding: 0;
  display: grid;
  gap: 0;
  max-width: 720px;
}

.page-about .about-flow-step {
  display: grid;
  grid-template-columns: 38px minmax(0, 1fr);
  gap: 14px;
  align-items: start;
  padding: 15px 0;
  border-top: 1px dashed var(--line-soft);
}

.page-about .about-flow-step:last-child {
  border-bottom: 1px dashed var(--line-soft);
}

.page-about .about-flow-num {
  font-family: var(--font-num);
  font-weight: 700;
  font-size: 13px;
  letter-spacing: .08em;
  color: var(--copper);
  line-height: 1.95;
}

.page-about .about-flow-step p {
  margin: 0;
  font-size: 14.5px;
  line-height: 1.8;
  color: rgba(232, 235, 230, .82);
}

/* ── 时间线 ── */
.page-about .about-timeline {
  list-style: none;
  margin: 0;
  padding: 0 0 0 26px;
  position: relative;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 6px;
  top: 8px;
  bottom: 8px;
  width: 2px;
  background: linear-gradient(180deg, var(--copper) 0%, rgba(192, 138, 78, .14) 100%);
}

.page-about .about-tl-item {
  position: relative;
  padding: 0 0 32px;
}

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

.page-about .about-tl-item::before {
  content: "";
  position: absolute;
  left: -28px;
  top: 5px;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--ink-900);
  border: 3px solid var(--flame);
  transition: transform var(--dur) var(--ease), box-shadow var(--dur) var(--ease);
}

.page-about .about-tl-item:hover::before {
  transform: scale(1.14);
  box-shadow: 0 0 0 5px var(--flame-soft);
}

.page-about .about-tl-year {
  display: block;
  font-family: var(--font-num);
  font-weight: 700;
  font-size: 17px;
  letter-spacing: .08em;
  color: var(--copper);
}

.page-about .about-tl-title {
  margin: 6px 0 0;
  font-size: 18px;
  font-weight: 700;
  line-height: 1.5;
  letter-spacing: .03em;
  color: var(--paper);
}

.page-about .about-tl-more {
  margin: 0;
  font-size: 14px;
  line-height: 1.8;
  color: var(--mid);
  max-height: 0;
  overflow: hidden;
  opacity: 0;
  transition: max-height .34s var(--ease), opacity .34s var(--ease), margin-top .34s var(--ease);
}

.page-about .about-tl-item:hover .about-tl-more,
.page-about .about-tl-item:focus-within .about-tl-more {
  max-height: 180px;
  opacity: 1;
  margin-top: 8px;
}

@media (hover: none) {
  .page-about .about-tl-more {
    max-height: none;
    opacity: 1;
    margin-top: 8px;
  }
}

.page-about .about-grid--visual .about-figure {
  margin: 0 0 4px;
}

/* ── 伙伴生态 ── */
.page-about .about-eco {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  max-width: 720px;
}

.page-about .about-eco-item {
  position: relative;
  padding: 14px 0 14px 20px;
  border-bottom: 1px solid var(--line-soft);
  font-size: 15px;
  line-height: 1.78;
  color: rgba(232, 235, 230, .84);
}

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

.page-about .about-eco-item::before {
  content: "";
  position: absolute;
  left: 0;
  top: 23px;
  width: 9px;
  height: 2px;
  background: var(--flame);
}

.page-about .about-eco-tags {
  list-style: none;
  margin: 24px 0 0;
  padding: 0;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.page-about .about-eco-tags li {
  font-family: var(--font-num);
  font-size: 13px;
  letter-spacing: .06em;
  color: var(--paper);
  border: 1px solid var(--copper-soft);
  border-radius: var(--radius-pill);
  padding: 7px 17px;
  background: rgba(192, 138, 78, .07);
}

/* ── 服务标准 ── */
.page-about .about-standards {
  list-style: none;
  margin: 0;
  padding: 0;
  max-width: 760px;
}

.page-about .about-stand {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 5px;
  padding: 16px 0;
  border-bottom: 1px solid var(--line-soft);
}

.page-about .about-stand:first-child {
  border-top: 1px solid var(--line-soft);
}

@media (min-width: 640px) {
  .page-about .about-stand {
    grid-template-columns: 148px minmax(0, 1fr);
    gap: 20px;
    align-items: baseline;
  }
}

.page-about .about-stand-name {
  font-family: var(--font-num);
  font-size: 12.5px;
  letter-spacing: .1em;
  color: var(--copper);
}

.page-about .about-stand-value {
  font-size: 15px;
  line-height: 1.72;
  color: var(--paper);
}

.page-about .about-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 32px;
}

.page-about .about-rail-link:focus-visible,
.page-about .about-inline-link:focus-visible,
.page-about .btn:focus-visible {
  outline: 2px solid var(--flame);
  outline-offset: 2px;
}

@media (max-width: 520px) {
  .page-about .about-line {
    grid-template-columns: minmax(0, 1fr);
    gap: 8px;
  }

  .page-about .about-flow-step {
    grid-template-columns: minmax(0, 1fr);
    gap: 6px;
  }

  .page-about .about-flow-num {
    line-height: 1.4;
  }

  .page-about .about-actions .btn {
    width: 100%;
    justify-content: center;
    text-align: center;
  }
}
</main>