.page-about {
  background-color: var(--deep-sea);
  color: var(--ice);
}

/* ---------- 首屏 ---------- */
.page-about .about-hero {
  position: relative;
  padding-top: calc(var(--header-h) + 34px);
  padding-bottom: 52px;
  overflow: hidden;
  background-image:
    linear-gradient(180deg, rgba(43, 227, 210, 0.07) 0%, rgba(6, 24, 43, 0) 58%),
    repeating-linear-gradient(90deg, rgba(28, 58, 86, 0.42) 0 1px, transparent 1px 78px),
    repeating-linear-gradient(0deg, rgba(28, 58, 86, 0.42) 0 1px, transparent 1px 78px);
}

.page-about .about-hero::after {
  content: "";
  position: absolute;
  right: -14%;
  top: 22%;
  width: 58%;
  height: 170px;
  background: linear-gradient(90deg, rgba(43, 227, 210, 0) 0%, rgba(43, 227, 210, 0.10) 62%, rgba(43, 227, 210, 0) 100%);
  transform: rotate(-8deg);
  pointer-events: none;
}

.page-about .about-hero .crumb {
  position: relative;
  z-index: 1;
  margin-bottom: 26px;
}

.page-about .about-hero .eyebrow {
  position: relative;
  z-index: 1;
  margin: 0;
}

.page-about .about-hero h1 {
  position: relative;
  z-index: 1;
  margin: 14px 0 0;
  font-size: clamp(32px, 8.4vw, 74px);
  line-height: 1.06;
  font-weight: 900;
  letter-spacing: -0.02em;
  max-width: 15ch;
  color: var(--ice);
}

.page-about .about-lede {
  position: relative;
  z-index: 1;
  margin: 22px 0 0;
  font-size: 16px;
  line-height: 1.78;
  color: var(--mist);
  max-width: 36em;
}

.page-about .about-figures {
  position: relative;
  z-index: 1;
  list-style: none;
  margin: 38px 0 0;
  padding: 0;
  border-top: 1px solid var(--grid);
}

.page-about .about-figure {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 18px 0;
  border-bottom: 1px solid var(--grid);
}

.page-about .about-figure-num {
  font-family: var(--font-mono);
  font-size: 30px;
  line-height: 1;
  font-weight: 700;
  letter-spacing: 0.01em;
  color: var(--cyan);
}

.page-about .about-figure-label {
  font-size: 13px;
  line-height: 1.6;
  letter-spacing: 0.02em;
  color: var(--mist);
}

/* ---------- 通用章节头 ---------- */
.page-about .about-section-head {
  max-width: 44em;
  margin-bottom: 28px;
}

.page-about .about-section-head .eyebrow {
  margin: 0;
}

.page-about .about-section-head h2 {
  margin: 10px 0 12px;
  font-size: clamp(24px, 5.6vw, 40px);
  line-height: 1.16;
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--ice);
}

.page-about .about-section-head p {
  margin: 0;
  font-size: 16px;
  line-height: 1.78;
  color: var(--mist);
  max-width: 38em;
}

.page-about .about-section-head a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(43, 227, 210, 0.4);
}

.page-about .about-section-head a:hover,
.page-about .about-section-head a:focus-visible {
  border-bottom-color: var(--cyan);
}

/* ---------- 平台定位 ---------- */
.page-about .about-scope-grid {
  display: grid;
  gap: 34px;
}

.page-about .about-scope-lead .eyebrow {
  margin: 0;
}

.page-about .about-scope-lead h2 {
  margin: 10px 0 16px;
  font-size: clamp(26px, 5.8vw, 42px);
  line-height: 1.14;
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--ice);
}

.page-about .about-scope-lead p {
  margin: 0 0 14px;
  font-size: 16px;
  line-height: 1.78;
  color: var(--mist);
  max-width: 36em;
}

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

.page-about .scope-list > li {
  position: relative;
  padding: 20px 0 20px 20px;
  border-top: 1px solid var(--grid);
}

.page-about .scope-list > li:last-child {
  border-bottom: 1px solid var(--grid);
}

.page-about .scope-list > li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 27px;
  width: 7px;
  height: 7px;
  background: var(--cyan);
  transform: rotate(45deg);
  transition: transform 0.24s var(--ease);
}

.page-about .scope-list > li:hover::before {
  transform: rotate(135deg);
}

.page-about .scope-list h3 {
  margin: 0 0 6px;
  font-size: 18px;
  font-weight: 700;
  line-height: 1.4;
  color: var(--ice);
}

.page-about .scope-list p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--mist);
}

/* ---------- 时间轴 ---------- */
.page-about .about-timeline-media {
  margin: 0 0 34px;
}

.page-about .about-timeline-media img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  background: var(--panel-blue);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 20px), calc(100% - 20px) 100%, 0 100%);
}

.page-about .tl {
  --tl-line-x: 56px;
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .tl-item {
  position: relative;
  display: grid;
  grid-template-columns: var(--tl-line-x) minmax(0, 1fr);
  column-gap: 16px;
  padding-bottom: 32px;
}

.page-about .tl-item::after {
  content: "";
  position: absolute;
  left: var(--tl-line-x);
  top: 26px;
  bottom: 0;
  width: 1px;
  background: var(--grid);
  transform: translateX(-0.5px);
}

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

.page-about .tl-item:last-child::after {
  display: none;
}

.page-about .tl-item::before {
  content: "";
  position: absolute;
  left: var(--tl-line-x);
  top: 26px;
  width: 9px;
  height: 9px;
  background: var(--cyan);
  transform: translate(-50%, -50%) rotate(45deg);
  box-shadow: 0 0 0 4px var(--deep-sea), 0 0 14px rgba(43, 227, 210, 0.55);
  z-index: 2;
  transition: background-color 0.24s var(--ease), box-shadow 0.24s var(--ease);
}

.page-about .tl-item:hover::before {
  background: var(--orange);
  box-shadow: 0 0 0 4px var(--deep-sea), 0 0 16px rgba(255, 107, 44, 0.6);
}

.page-about .tl-year {
  padding-right: 14px;
  padding-top: 18px;
  text-align: right;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.02em;
  color: var(--mist);
  transition: color 0.24s var(--ease);
}

.page-about .tl-item:hover .tl-year {
  color: var(--cyan);
}

.page-about .tl-body h3 {
  margin: 0 0 8px;
  font-size: 18px;
  font-weight: 700;
  line-height: 1.42;
  color: var(--ice);
}

.page-about .tl-body p {
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--mist);
  max-width: 38em;
}

.page-about .tl-note {
  max-height: 0;
  opacity: 0;
  overflow: hidden;
  margin-top: 0;
  padding-left: 12px;
  border-left: 2px solid var(--cyan);
  font-size: 13.5px;
  line-height: 1.72;
  color: var(--ice);
  transition: max-height 0.34s var(--ease), opacity 0.26s var(--ease), margin-top 0.34s var(--ease);
}

.page-about .tl-item:hover .tl-note,
.page-about .tl-item:focus-within .tl-note {
  max-height: 14em;
  opacity: 1;
  margin-top: 12px;
}

/* ---------- 内容与数据来源 ---------- */
.page-about .source-grid {
  display: grid;
  gap: 30px;
}

.page-about .source-copy .eyebrow {
  margin: 0;
}

.page-about .source-copy h2 {
  margin: 10px 0 14px;
  font-size: clamp(24px, 5.4vw, 38px);
  line-height: 1.16;
  font-weight: 800;
  letter-spacing: -0.02em;
  color: var(--ice);
}

.page-about .source-copy > p {
  margin: 0;
  font-size: 16px;
  line-height: 1.78;
  color: var(--mist);
  max-width: 36em;
}

.page-about .source-list {
  margin: 26px 0 0;
}

.page-about .source-list > div {
  padding: 16px 0;
  border-top: 1px solid var(--grid);
}

.page-about .source-list > div:last-child {
  border-bottom: 1px solid var(--grid);
}

.page-about .source-list dt {
  margin-bottom: 5px;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--cyan);
}

.page-about .source-list dd {
  margin: 0;
  font-size: 15px;
  line-height: 1.76;
  color: var(--mist);
}

.page-about .source-media {
  margin: 0;
}

.page-about .source-media img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  aspect-ratio: 3 / 2;
  object-fit: cover;
  background: var(--panel-blue);
  clip-path: polygon(22px 0, 100% 0, 100% 100%, 0 100%, 0 22px);
}

/* ---------- 团队分工 ---------- */
.page-about .about-team-media {
  margin: 0 0 30px;
}

.page-about .about-team-media img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  aspect-ratio: 10 / 7;
  object-fit: cover;
  background: var(--panel-blue);
  clip-path: polygon(0 0, 100% 0, 100% 100%, 26px 100%, 0 calc(100% - 26px));
}

.page-about .team-split {
  display: grid;
  gap: 18px;
}

.page-about .team-card {
  padding: 24px 22px 20px;
  background: var(--panel-blue);
  border: 1px solid var(--grid);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 16px), calc(100% - 16px) 100%, 0 100%);
}

.page-about .team-num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(40px, 10vw, 56px);
  line-height: 1;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--cyan);
}

.page-about .team-card h3 {
  margin: 12px 0 8px;
  font-size: 18px;
  font-weight: 700;
  color: var(--ice);
}

.page-about .team-card > p {
  margin: 0;
  font-size: 15px;
  line-height: 1.75;
  color: var(--mist);
}

.page-about .team-more {
  margin-top: 16px;
  padding-top: 4px;
  border-top: 1px solid var(--grid);
}

.page-about .team-more summary {
  display: flex;
  align-items: center;
  gap: 8px;
  min-height: 44px;
  cursor: pointer;
  list-style: none;
  font-family: var(--font-mono);
  font-size: 12px;
  letter-spacing: 0.08em;
  color: var(--cyan);
}

.page-about .team-more summary::-webkit-details-marker {
  display: none;
}

.page-about .team-more summary::before {
  content: "+";
  font-size: 15px;
  line-height: 1;
}

.page-about .team-more[open] summary::before {
  content: "\2013";
}

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

.page-about .team-more ul {
  list-style: none;
  margin: 6px 0 8px;
  padding: 0;
}

.page-about .team-more li {
  position: relative;
  margin-bottom: 7px;
  padding-left: 15px;
  font-size: 14px;
  line-height: 1.72;
  color: var(--mist);
}

.page-about .team-more li::before {
  content: "";
  position: absolute;
  left: 0;
  top: 10px;
  width: 6px;
  height: 1px;
  background: var(--cyan);
}

/* ---------- 内容标准 ---------- */
.page-about .std-list {
  list-style: none;
  margin: 0;
  padding: 0;
}

.page-about .std-list > li {
  display: grid;
  grid-template-columns: 40px minmax(0, 1fr);
  gap: 14px;
  padding: 20px 0;
  border-top: 1px solid var(--grid);
}

.page-about .std-list > li:last-child {
  border-bottom: 1px solid var(--grid);
}

.page-about .std-index {
  padding-top: 4px;
  font-family: var(--font-mono);
  font-size: 13px;
  letter-spacing: 0.08em;
  color: var(--cyan);
}

.page-about .std-list h3 {
  margin: 0 0 6px;
  font-size: 17px;
  font-weight: 700;
  color: var(--ice);
}

.page-about .std-list p {
  margin: 0;
  font-size: 15px;
  line-height: 1.78;
  color: var(--mist);
  max-width: 40em;
}

.page-about .std-footnote {
  margin: 22px 0 0;
  font-size: 14px;
  line-height: 1.75;
  color: var(--mist);
}

.page-about .std-footnote a {
  color: var(--cyan);
  text-decoration: none;
  border-bottom: 1px solid rgba(43, 227, 210, 0.4);
}

.page-about .std-footnote a:hover,
.page-about .std-footnote a:focus-visible {
  border-bottom-color: var(--cyan);
}

/* ---------- 接下来一年 ---------- */
.page-about .next-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  gap: 16px;
}

.page-about .next-item {
  padding: 22px 20px 24px;
  background: linear-gradient(158deg, rgba(12, 39, 64, 0.95) 0%, rgba(12, 39, 64, 0.5) 100%);
  border-top: 2px solid var(--cyan);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 14px), calc(100% - 14px) 100%, 0 100%);
}

.page-about .next-item h3 {
  margin: 0 0 8px;
  font-size: 17px;
  font-weight: 700;
  line-height: 1.4;
  color: var(--ice);
}

.page-about .next-item p {
  margin: 0;
  font-size: 15px;
  line-height: 1.76;
  color: var(--mist);
}

/* ---------- 收束条 ---------- */
.page-about .about-cta {
  padding-bottom: 74px;
}

.page-about .cta-band {
  display: grid;
  gap: 20px;
  padding: 28px 22px;
  background: var(--panel-blue);
  border: 1px solid var(--grid);
  border-left: 3px solid var(--orange);
  clip-path: polygon(0 0, 100% 0, 100% calc(100% - 18px), calc(100% - 18px) 100%, 0 100%);
}

.page-about .cta-band p {
  margin: 0;
  font-size: 16px;
  line-height: 1.72;
  color: var(--ice);
  max-width: 40em;
}

.page-about .cta-actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
}

/* ---------- 平板 ---------- */
@media (min-width: 720px) {
  .page-about .about-hero {
    padding-top: calc(var(--header-h) + 52px);
    padding-bottom: 66px;
  }

  .page-about .about-lede {
    font-size: 17px;
  }

  .page-about .about-figures {
    display: grid;
    grid-template-columns: repeat(3, minmax(0, 1fr));
    margin-top: 46px;
  }

  .page-about .about-figure {
    padding: 22px 26px;
    border-bottom: 0;
    border-left: 1px solid var(--grid);
  }

  .page-about .about-figure:first-child {
    padding-left: 0;
    border-left: 0;
  }

  .page-about .tl {
    --tl-line-x: 84px;
  }

  .page-about .tl-item {
    column-gap: 26px;
    padding-bottom: 38px;
  }

  .page-about .tl-year {
    font-size: 15px;
    padding-right: 20px;
  }

  .page-about .tl-body h3 {
    font-size: 19px;
  }

  .page-about .about-section-head p,
  .page-about .about-scope-lead p,
  .page-about .source-copy > p {
    font-size: 17px;
  }

  .page-about .cta-band {
    padding: 32px 30px;
  }
}

/* ---------- 桌面 ---------- */
@media (min-width: 960px) {
  .page-about .about-scope-grid {
    grid-template-columns: minmax(0, 1fr) minmax(0, 1.06fr);
    gap: 56px;
    align-items: start;
  }

  .page-about .source-grid {
    grid-template-columns: minmax(0, 1.06fr) minmax(0, 0.86fr);
    gap: 52px;
    align-items: center;
  }

  .page-about .about-timeline-media {
    margin-bottom: 46px;
  }

  .page-about .team-split {
    grid-template-columns: 1.18fr 0.95fr 0.88fr;
    gap: 20px;
    align-items: start;
  }

  .page-about .team-card:nth-child(2) {
    margin-top: 18px;
  }

  .page-about .team-card:nth-child(3) {
    margin-top: 36px;
  }

  .page-about .std-list > li {
    grid-template-columns: 54px minmax(0, 1fr);
    gap: 20px;
    padding: 24px 0;
  }

  .page-about .next-list {
    grid-template-columns: repeat(3, minmax(0, 1fr));
    gap: 20px;
  }

  .page-about .next-item:nth-child(2) {
    margin-top: 22px;
  }

  .page-about .next-item:nth-child(3) {
    margin-top: 44px;
  }

  .page-about .cta-band {
    grid-template-columns: minmax(0, 1fr) auto;
    align-items: center;
    gap: 36px;
    padding: 36px 38px;
  }
}

/* ---------- 触摸设备：说明文字常显 ---------- */
@media (hover: none) {
  .page-about .tl-note {
    max-height: none;
    opacity: 1;
    margin-top: 12px;
  }
}

/* ---------- 降低动效 ---------- */
@media (prefers-reduced-motion: reduce) {
  .page-about .tl-note,
  .page-about .tl-year,
  .page-about .tl-item::before,
  .page-about .scope-list > li::before {
    transition: none;
  }
}