.page-about {
  --about-paper: #FFFFFF;
  --about-paper-line: #D0DCE4;
  --about-paper-shadow: 6px 6px 0 rgba(10, 30, 60, 0.05);
  --about-paper-shadow-neon: 10px 10px 0 rgba(0, 230, 138, 0.12);
  overflow-x: hidden;
  background: var(--c-white);
  color: var(--c-ink);
  font-family: var(--font-body);
  line-height: 1.6;
}

.page-about .breadcrumb {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  font-size: 0.78rem;
  color: rgba(255, 255, 255, 0.55);
}

.page-about .breadcrumb a {
  color: rgba(255, 255, 255, 0.7);
  text-decoration: none;
}

.page-about .breadcrumb a:hover,
.page-about .breadcrumb a:focus {
  color: var(--c-neon);
}

.page-about .breadcrumb .current {
  color: var(--c-neon);
}

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

/* ---------- 首屏主视觉 ---------- */
.page-about .about-hero {
  position: relative;
  background:
    radial-gradient(circle at 74% 20%, rgba(0, 230, 138, 0.16), transparent 28%),
    linear-gradient(135deg, var(--c-space) 0%, var(--c-space-deep) 100%);
  color: var(--c-white);
  overflow: hidden;
}

.page-about .about-hero::before {
  content: "";
  position: absolute;
  top: 0;
  right: -90px;
  width: 240px;
  height: 400px;
  background: linear-gradient(180deg, rgba(255, 90, 54, 0.3), transparent 72%);
  clip-path: polygon(100% 0, 100% 100%, 0 100%);
  pointer-events: none;
}

.page-about .about-hero__inner {
  position: relative;
  z-index: 1;
  display: grid;
  gap: 2rem;
  padding: 2.5rem 0 4.75rem;
}

.page-about .about-hero__kicker {
  display: inline-flex;
  align-items: center;
  gap: 0.6rem;
  font-family: var(--font-mono);
  font-size: 0.84rem;
  letter-spacing: 0.08em;
  color: var(--c-neon);
  margin-bottom: 1rem;
}

.page-about .about-hero__kicker::before {
  content: "";
  width: 28px;
  height: 4px;
  background: var(--c-neon);
  transform: skewX(-24deg);
  flex: 0 0 auto;
}

.page-about .about-hero h1 {
  font-family: var(--font-display);
  font-size: clamp(2rem, 5vw, 3.15rem);
  font-weight: 900;
  line-height: 1.18;
  letter-spacing: -0.02em;
  margin-bottom: 1.1rem;
  max-width: 16em;
}

.page-about .about-hero__lead {
  font-size: 1rem;
  line-height: 1.8;
  color: rgba(255, 255, 255, 0.82);
  max-width: 44em;
  margin-bottom: 1.6rem;
}

.page-about .about-hero__note {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.65rem;
  margin-top: 1.25rem;
}

.page-about .about-hero__note .data-note {
  color: rgba(255, 255, 255, 0.78);
}

/* 首屏媒体：纸张包边 + 轻微旋转 */
.page-about .about-media-frame {
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.14);
  padding: 0.7rem;
  transform: rotate(1deg);
}

.page-about .about-media-frame img {
  display: block;
  width: 100%;
  height: auto;
  clip-path: polygon(0 4%, 100% 0, 100% 96%, 0 100%);
}

.page-about .about-media-caption {
  margin-top: 0.7rem;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  letter-spacing: 0.09em;
  color: rgba(255, 255, 255, 0.45);
  text-align: right;
}

@media (min-width: 920px) {
  .page-about .about-hero__inner {
    grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
    align-items: center;
    gap: 3rem;
    padding-bottom: 6.5rem;
  }

  .page-about .about-hero .breadcrumb {
    grid-column: 1 / -1;
  }
}

/* ---------- 通用分区 ---------- */
.page-about .about-section {
  padding: 4rem 0;
}

@media (min-width: 768px) {
  .page-about .about-section {
    padding: 5.5rem 0;
  }
}

.page-about .about-section-head {
  margin-bottom: 2.75rem;
  max-width: 46rem;
}

.page-about .about-section-head .section-index {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: var(--c-orange);
  border: 1px solid var(--about-paper-line);
  padding: 0.3em 0.7em;
  margin-bottom: 1rem;
}

.page-about .about-section-head .section-title {
  font-family: var(--font-display);
  font-size: clamp(1.7rem, 4vw, 2.4rem);
  font-weight: 900;
  line-height: 1.2;
  margin-bottom: 0.75rem;
  position: relative;
  padding-bottom: 0.35em;
  border-bottom: 2px solid var(--about-paper-line);
}

.page-about .about-section-head .section-title::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -2px;
  width: 3.2em;
  height: 4px;
  background: var(--c-neon);
  transform: skewX(-22deg);
  transform-origin: left center;
}

.page-about .about-section-head .section-sub {
  color: var(--c-muted);
  font-size: 0.95rem;
  line-height: 1.7;
  margin-top: 0.85rem;
}

/* ---------- 数据与能力 ---------- */
.page-about .about-capability {
  background: var(--c-light);
}

.page-about .about-capability__grid {
  display: grid;
  gap: 2.25rem;
  margin-bottom: 2rem;
}

.page-about .about-capability__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.8rem;
}

.page-about .about-stat-item {
  position: relative;
  background: var(--about-paper);
  border: 1px solid var(--about-paper-line);
  padding: 1.4rem 1.15rem 1.4rem 1.35rem;
  box-shadow: var(--about-paper-shadow);
}

.page-about .about-stat-item::before {
  content: "";
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  width: 4px;
  background: var(--c-neon);
  transform: skewX(-10deg);
}

.page-about .about-stat-item:nth-child(even)::before {
  background: var(--c-orange);
}

.page-about .about-stat-num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(1.8rem, 4.4vw, 2.5rem);
  font-weight: 700;
  line-height: 1;
  letter-spacing: -0.03em;
  color: var(--c-ink);
}

.page-about .about-stat-unit {
  font-size: 0.5em;
  font-weight: 600;
  color: var(--c-muted);
  margin-left: 0.2em;
}

.page-about .about-stat-label {
  display: block;
  margin-top: 0.5rem;
  font-size: 0.78rem;
  line-height: 1.45;
  color: var(--c-muted);
}

.page-about .about-capability__media {
  clip-path: polygon(0 5%, 100% 0, 100% 95%, 0 100%);
  overflow: hidden;
  background: var(--c-space);
}

.page-about .about-capability__media img {
  display: block;
  width: 100%;
  height: auto;
}

.page-about .about-capability__note {
  display: flex;
  gap: 1rem;
  margin-top: 2.5rem;
  padding: 1.4rem 1.5rem;
  background: var(--about-paper);
  border-left: 4px solid var(--c-space);
  box-shadow: 4px 4px 0 rgba(10, 30, 60, 0.04);
}

.page-about .about-capability__note p {
  font-size: 0.88rem;
  line-height: 1.75;
  color: var(--c-muted);
}

@media (min-width: 900px) {
  .page-about .about-capability__grid {
    grid-template-columns: minmax(0, 1.15fr) minmax(0, 0.85fr);
    align-items: center;
    gap: 3rem;
  }

  .page-about .about-capability__stats {
    gap: 1rem;
  }
}

/* ---------- 覆盖范围 ---------- */
.page-about .about-coverage {
  position: relative;
  background: var(--c-white);
  overflow: hidden;
}

.page-about .about-coverage::before {
  content: "";
  position: absolute;
  right: -4rem;
  top: 3rem;
  width: 10rem;
  height: 10rem;
  background: var(--c-neon-soft);
  clip-path: polygon(50% 0, 100% 50%, 50% 100%, 0 50%);
  opacity: 0.6;
  pointer-events: none;
}

.page-about .about-coverage__layout {
  position: relative;
  display: grid;
  gap: 2.25rem;
}

.page-about .about-coverage__stats {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 0.85rem;
}

.page-about .about-cov-stat {
  position: relative;
  overflow: hidden;
  background: var(--c-space);
  color: var(--c-white);
  padding: 1.6rem 1.3rem;
}

.page-about .about-cov-stat::after {
  content: "";
  position: absolute;
  right: -1.25rem;
  bottom: -1.25rem;
  width: 6rem;
  height: 6rem;
  background: var(--c-neon);
  clip-path: polygon(100% 0, 100% 100%, 0 100%);
  opacity: 0.3;
}

.page-about .about-cov-num {
  display: block;
  font-family: var(--font-mono);
  font-size: clamp(2.1rem, 6vw, 3rem);
  font-weight: 700;
  line-height: 1;
  color: var(--c-neon);
}

.page-about .about-cov-suffix {
  display: block;
  margin-top: 0.55rem;
  font-size: 0.82rem;
  color: rgba(255, 255, 255, 0.82);
}

.page-about .about-coverage__cats {
  background: var(--c-light);
  padding: 2rem 1.5rem 1.75rem;
  border: 1px dashed var(--c-line);
}

.page-about .about-cats-title {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  letter-spacing: 0.05em;
  color: var(--c-space);
  font-weight: 700;
  margin-bottom: 1.1rem;
}

.page-about .about-cats-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.55rem;
  margin-bottom: 1.5rem;
}

.page-about .about-coverage__desc {
  font-size: 0.85rem;
  line-height: 1.7;
  color: var(--c-muted);
  border-top: 1px solid var(--c-line);
  padding-top: 1.2rem;
}

@media (min-width: 900px) {
  .page-about .about-coverage__layout {
    grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
    align-items: stretch;
    gap: 3rem;
  }

  .page-about .about-coverage__stats {
    gap: 1rem;
  }
}

/* ---------- 版本里程碑 ---------- */
.page-about .about-milestone {
  background:
    radial-gradient(circle at 18% 0%, rgba(0, 230, 138, 0.1), transparent 34%),
    var(--c-space);
  color: var(--c-white);
}

.page-about .about-milestone .about-section-head .section-index {
  border-color: rgba(255, 255, 255, 0.22);
  color: var(--c-neon);
}

.page-about .about-milestone .about-section-head .section-title {
  border-bottom-color: rgba(255, 255, 255, 0.22);
  color: var(--c-white);
}

.page-about .about-milestone .about-section-head .section-title::after {
  background: var(--c-neon);
}

.page-about .about-milestone .about-section-head .section-sub {
  color: rgba(255, 255, 255, 0.62);
}

.page-about .about-timeline {
  position: relative;
  display: grid;
  gap: 1.5rem;
  margin: 0;
  padding-left: 1.6rem;
}

.page-about .about-timeline::before {
  content: "";
  position: absolute;
  left: 7px;
  top: 6px;
  bottom: 12px;
  width: 2px;
  background: repeating-linear-gradient(to bottom, rgba(0, 230, 138, 0.5) 0 4px, transparent 4px 10px);
}

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

.page-about .about-timeline__item::before {
  content: "";
  position: absolute;
  left: -1.62rem;
  top: 1.15rem;
  width: 10px;
  height: 10px;
  background: var(--c-space);
  border: 2px solid var(--c-neon);
  border-radius: 50%;
  box-shadow: 0 0 0 5px rgba(0, 230, 138, 0.1);
  z-index: 1;
}

.page-about .about-timeline__item--current::before {
  background: var(--c-neon);
}

.page-about .about-timeline__round {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  letter-spacing: 0.08em;
  color: var(--c-neon);
  background: rgba(0, 230, 138, 0.1);
  border: 1px solid rgba(0, 230, 138, 0.28);
  padding: 0.2em 0.7em;
  margin-bottom: 0.85rem;
}

.page-about .about-timeline__body {
  background: var(--c-white);
  color: var(--c-ink);
  border-radius: var(--radius-sm);
  padding: 1.35rem 1.4rem 1.5rem;
  box-shadow: var(--about-paper-shadow-neon);
}

.page-about .about-timeline__body h3 {
  font-family: var(--font-display);
  font-size: 1.05rem;
  font-weight: 800;
  color: var(--c-space);
  margin-bottom: 0.45rem;
}

.page-about .about-timeline__body p {
  font-size: 0.85rem;
  line-height: 1.7;
  color: var(--c-muted);
  margin-bottom: 0.5rem;
}

.page-about .about-timeline__body .tag {
  margin-top: 0.6rem;
}

.page-about .about-milestone__media {
  margin-top: 3.5rem;
  border: 1px solid rgba(255, 255, 255, 0.12);
  padding: 0.6rem;
}

.page-about .about-milestone__media img {
  display: block;
  width: 100%;
  height: auto;
}

@media (min-width: 920px) {
  .page-about .about-timeline {
    padding-left: 2.4rem;
    gap: 2rem;
  }

  .page-about .about-timeline::before {
    left: 11px;
  }

  .page-about .about-timeline__item::before {
    left: -2.4rem;
    width: 12px;
    height: 12px;
  }
}

/* ---------- 资质与合作 ---------- */
.page-about .about-trust {
  background: var(--c-light);
}

.page-about .about-trust__grid {
  display: grid;
  gap: 1.25rem;
}

.page-about .about-trust__card {
  position: relative;
  overflow: hidden;
  background: var(--c-white);
  border: 1px solid var(--c-line);
  padding: 1.75rem 1.6rem 1.5rem;
  box-shadow: 5px 5px 0 rgba(10, 30, 60, 0.045);
}

.page-about .about-trust__card::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 3px;
  height: 100%;
  background: linear-gradient(180deg, var(--c-neon) 0%, transparent 100%);
}

.page-about .about-trust__label {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.7rem;
  font-weight: 600;
  letter-spacing: 0.12em;
  color: var(--c-orange);
  margin-bottom: 0.7rem;
}

.page-about .about-trust__card h3 {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 800;
  color: var(--c-ink);
  margin-bottom: 0.6rem;
}

.page-about .about-trust__card p {
  font-size: 0.86rem;
  line-height: 1.7;
  color: var(--c-muted);
}

.page-about .about-trust .callout {
  margin-top: 2.5rem;
  background: var(--c-white);
}

.page-about .callout a {
  color: var(--c-orange);
  font-weight: 700;
  text-decoration: underline;
  text-underline-offset: 2px;
}

@media (min-width: 820px) {
  .page-about .about-trust__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

/* ---------- 章节索引 / 目录 ---------- */
.page-about .about-directory {
  background: linear-gradient(135deg, var(--c-space) 0%, #0B2745 100%);
  color: var(--c-white);
  padding: 4.5rem 0 5rem;
}

.page-about .about-directory .section-index {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  color: var(--c-neon);
  border: 1px solid rgba(255, 255, 255, 0.2);
  padding: 0.3em 0.7em;
  margin-bottom: 1rem;
}

.page-about .about-directory .section-title {
  font-family: var(--font-display);
  font-size: clamp(1.7rem, 4vw, 2.4rem);
  font-weight: 900;
  line-height: 1.2;
  position: relative;
  padding-bottom: 0.35em;
  border-bottom: 2px solid rgba(255, 255, 255, 0.2);
}

.page-about .about-directory .section-title::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -2px;
  width: 3.2em;
  height: 4px;
  background: var(--c-neon);
  transform: skewX(-22deg);
}

.page-about .about-directory__grid {
  display: grid;
  grid-template-columns: minmax(0, 1fr);
  gap: 0.9rem;
  margin-top: 2.5rem;
}

.page-about .about-directory__item {
  display: block;
  color: var(--c-white);
  text-decoration: none;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid rgba(255, 255, 255, 0.14);
  padding: 1.5rem 1.4rem;
  transition: border-color 0.3s var(--ease), background 0.3s var(--ease), transform 0.3s var(--ease);
}

.page-about .about-directory__item:hover,
.page-about .about-directory__item:focus {
  border-color: var(--c-neon);
  background: rgba(0, 230, 138, 0.1);
  transform: translateY(-3px);
}

.page-about .about-directory__item:hover .about-directory__name,
.page-about .about-directory__item:focus .about-directory__name {
  color: var(--c-neon);
}

.page-about .about-directory__num {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--c-neon);
  margin-bottom: 0.6rem;
}

.page-about .about-directory__name {
  display: block;
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 800;
  color: var(--c-white);
  margin-bottom: 0.3rem;
  transition: color 0.3s var(--ease);
}

.page-about .about-directory__desc {
  display: block;
  font-size: 0.8rem;
  color: rgba(255, 255, 255, 0.5);
}

@media (min-width: 680px) {
  .page-about .about-directory__grid {
    grid-template-columns: repeat(2, minmax(0, 1fr));
  }
}

@media (min-width: 1080px) {
  .page-about .about-directory__grid {
    grid-template-columns: repeat(4, minmax(0, 1fr));
  }
}