.page-about {
  --about-hero-bg: rgba(0, 230, 118, 0.06);
  --about-eco-bg: rgba(30, 144, 255, 0.05);
}

/* ==================== Hero 品牌叙事 ==================== */
.page-about .about-hero {
  position: relative;
  padding: 32px 0 56px;
  overflow: hidden;
}
.page-about .about-hero::before {
  content: "60+";
  position: absolute;
  top: 72px;
  right: -14px;
  font-family: var(--font-mono);
  font-size: 140px;
  font-weight: 800;
  line-height: 1;
  color: transparent;
  -webkit-text-stroke: 2px rgba(0, 230, 118, 0.18);
  transform: rotate(-6deg);
  pointer-events: none;
  z-index: 0;
}
.page-about .about-hero__grid {
  position: relative;
  z-index: 1;
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
}
.page-about .about-hero__copy {
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 16px;
}
.page-about .about-hero__copy .sk-h1 {
  margin: 0;
  font-size: clamp(1.6rem, 4.5vw, 2.6rem);
  line-height: 1.25;
  letter-spacing: 0.01em;
}
.page-about .about-hero__copy .sk-lead {
  margin: 0;
  font-size: 1.02rem;
  line-height: 1.8;
  color: var(--text-high);
}
.page-about .about-hero__copy p:not(.sk-lead) {
  margin: 0;
  color: var(--text-mid);
  line-height: 1.8;
  font-size: 0.94rem;
}
.page-about .about-hero__actions {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-top: 8px;
}
.page-about .about-hero__panel {
  display: flex;
  flex-direction: column;
  gap: 24px;
}
.page-about .about-hero__stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 10px;
}
.page-about .about-hero__stat {
  display: flex;
  flex-direction: column;
  gap: 6px;
  padding: 18px 14px;
  background: var(--secondary-bg);
  border-left: 3px solid var(--accent);
  transition: transform 0.3s var(--ease);
}
.page-about .about-hero__stat:nth-child(2) {
  border-left-color: var(--accent-blue);
}
.page-about .about-hero__stat:nth-child(3) {
  border-left-color: var(--accent-orange);
}
@media (hover: hover) {
  .page-about .about-hero__stat:hover {
    transform: translateY(-3px);
  }
}
.page-about .about-hero__stat .sk-num {
  font-size: 1.6rem;
  line-height: 1;
  word-break: keep-all;
}
.page-about .about-hero__stat-label {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  color: var(--text-mid);
  letter-spacing: 0.06em;
}
.page-about .about-hero__figure {
  margin: 0;
}
.page-about .about-hero__img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  aspect-ratio: 1;
  object-fit: cover;
  background: var(--secondary-bg);
}

/* ==================== 时间轴 ==================== */
.page-about .about-timeline {
  position: relative;
  padding: 48px 0 56px;
  background: linear-gradient(180deg, var(--secondary-bg) 0%, transparent 120%);
}
.page-about .about-timeline__head {
  margin-bottom: 24px;
}
.page-about .about-timeline__head .sk-h2 {
  margin: 8px 0 12px;
}
.page-about .about-timeline__lead {
  color: var(--text-mid);
  line-height: 1.7;
  max-width: 540px;
  margin: 0;
}
.page-about .about-timeline__list {
  position: relative;
}
.page-about .about-timeline__item {
  display: grid;
  grid-template-columns: 1fr;
  gap: 12px;
  padding: 28px 0;
  border-bottom: 1px solid var(--divider);
  position: relative;
}
.page-about .about-timeline__year {
  display: flex;
  align-items: center;
}
.page-about .about-timeline__year-num {
  display: inline-block;
  font-family: var(--font-mono);
  font-size: 2rem;
  font-weight: 800;
  line-height: 1.2;
  color: var(--text-high);
  background: linear-gradient(135deg, rgba(0, 230, 118, 0.14), rgba(0, 230, 118, 0.02));
  padding: 10px 22px 10px 14px;
  border-left: 4px solid var(--accent);
  clip-path: polygon(0 0, 100% 0, calc(100% - 10px) 100%, 0 100%);
}
.page-about .about-timeline__body {
  background: var(--card-bg);
  border-left: 2px solid var(--divider);
  padding: 18px 20px;
  transition: border-color 0.3s var(--ease), transform 0.3s var(--ease);
}
@media (hover: hover) {
  .page-about .about-timeline__item:hover .about-timeline__body {
    border-left-color: var(--accent);
    transform: translateX(4px);
  }
}
.page-about .about-timeline__body h3 {
  margin: 0 0 8px;
  font-size: 1.05rem;
  color: var(--text-high);
  font-weight: 600;
}
.page-about .about-timeline__body p {
  margin: 0;
  color: var(--text-mid);
  line-height: 1.7;
  font-size: 0.92rem;
}
.page-about .about-timeline__img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  margin-top: 32px;
  object-fit: cover;
  background: var(--secondary-bg);
}
.page-about .about-guide {
  margin-top: 24px;
  padding: 20px 22px;
  background: linear-gradient(135deg, rgba(30, 144, 255, 0.1), rgba(30, 144, 255, 0.02));
  border-left: 4px solid var(--accent-blue);
}
.page-about .about-guide__title {
  margin: 0 0 10px;
  font-family: var(--font-mono);
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--accent-blue);
  letter-spacing: 0.08em;
}
.page-about .about-guide__list {
  margin: 0;
  padding: 0;
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 8px;
}
.page-about .about-guide__list li {
  color: var(--text-mid);
  line-height: 1.7;
  font-size: 0.92rem;
}
.page-about .about-guide__list a {
  color: var(--accent);
  text-underline-offset: 4px;
}

/* ==================== 资质与安全 ==================== */
.page-about .about-cert {
  padding: 48px 0 56px;
}
.page-about .about-cert__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 32px;
}
.page-about .about-cert__copy .sk-h2 {
  margin: 8px 0 12px;
}
.page-about .about-cert__copy > p {
  color: var(--text-mid);
  line-height: 1.8;
  margin: 0 0 20px;
}
.page-about .about-cert__item {
  background: var(--secondary-bg);
  border: 1px solid var(--divider);
  margin-bottom: 10px;
  transition: border-color 0.3s var(--ease);
}
.page-about .about-cert__item[open] {
  border-color: var(--accent);
}
.page-about .about-cert__item summary {
  cursor: pointer;
  padding: 16px 48px 16px 20px;
  font-weight: 600;
  font-size: 0.94rem;
  color: var(--text-high);
  list-style: none;
  position: relative;
  transition: color 0.3s var(--ease);
}
.page-about .about-cert__item summary::-webkit-details-marker {
  display: none;
}
.page-about .about-cert__item summary::after {
  content: "+";
  position: absolute;
  right: 18px;
  top: 50%;
  transform: translateY(-50%);
  font-family: var(--font-mono);
  font-size: 1.2rem;
  color: var(--accent);
  transition: transform 0.3s var(--ease);
}
.page-about .about-cert__item[open] summary::after {
  content: "−";
}
.page-about .about-cert__item p {
  margin: 0;
  padding: 0 20px 16px;
  color: var(--text-mid);
  font-size: 0.88rem;
  line-height: 1.7;
}
.page-about .about-cert__visual {
  display: flex;
  flex-direction: column;
  gap: 14px;
}
.page-about .about-cert__img {
  display: block;
  width: 100%;
  max-width: 100%;
  height: auto;
  aspect-ratio: 5 / 3;
  object-fit: cover;
  background: var(--secondary-bg);
}
.page-about .about-cert__note {
  margin: 0;
  color: var(--text-mid);
  font-size: 0.82rem;
  line-height: 1.7;
}
.page-about .about-cert__note a {
  color: var(--accent);
  text-underline-offset: 4px;
}

/* ==================== 内容合作生态 ==================== */
.page-about .about-eco {
  padding: 48px 0 64px;
  background: var(--about-eco-bg);
}
.page-about .about-eco__head {
  margin-bottom: 28px;
}
.page-about .about-eco__head .sk-h2 {
  margin: 8px 0 12px;
}
.page-about .about-eco__head p {
  color: var(--text-mid);
  line-height: 1.7;
  max-width: 560px;
  margin: 0;
}
.page-about .about-eco__grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}
.page-about .about-eco__card {
  padding: 24px 20px;
  display: flex;
  flex-direction: column;
  align-items: flex-start;
  gap: 10px;
  height: 100%;
}
.page-about .about-eco__card h3 {
  margin: 4px 0 0;
  font-size: 1.05rem;
  color: var(--text-high);
}
.page-about .about-eco__card p {
  margin: 0;
  color: var(--text-mid);
  line-height: 1.7;
  font-size: 0.92rem;
  flex: 1;
}
.page-about .about-eco__link {
  color: var(--accent);
  font-size: 0.88rem;
  font-weight: 600;
  text-decoration: none;
  text-underline-offset: 4px;
  transition: text-decoration 0.3s var(--ease);
}
@media (hover: hover) {
  .page-about .about-eco__link:hover {
    text-decoration: underline;
  }
}

/* ==================== 桌面端媒体查询 ==================== */
@media (min-width: 768px) {
  .page-about .about-hero {
    padding: 48px 0 72px;
  }
  .page-about .about-hero::before {
    font-size: 180px;
    top: 40px;
  }
  .page-about .about-hero__grid {
    grid-template-columns: 5fr 7fr;
    gap: 48px;
    align-items: start;
  }
  .page-about .about-hero__copy {
    gap: 18px;
  }
  .page-about .about-hero__stats {
    grid-template-columns: repeat(3, 1fr);
  }
  .page-about .about-hero__stat {
    padding: 22px 16px;
  }
  .page-about .about-hero__stat .sk-num {
    font-size: 2rem;
  }

  .page-about .about-timeline__item {
    grid-template-columns: 180px 1fr;
    gap: 28px;
  }
  .page-about .about-timeline__year {
    justify-content: flex-end;
  }
  .page-about .about-timeline__year-num {
    font-size: 2.6rem;
    padding: 12px 24px 12px 18px;
  }
  .page-about .about-timeline__body {
    margin: 8px 0 0;
    border-left: 2px solid transparent;
    position: relative;
  }
  .page-about .about-timeline__body::before {
    content: "";
    position: absolute;
    left: -35px;
    top: 22px;
    width: 14px;
    height: 14px;
    background: var(--primary-bg);
    border: 3px solid var(--accent);
    border-radius: 50%;
    transition: background 0.3s var(--ease);
  }
  @media (hover: hover) {
    .page-about .about-timeline__item:hover .about-timeline__body::before {
      background: var(--accent);
    }
  }
  .page-about .about-guide {
    padding: 24px 32px;
  }

  .page-about .about-cert__grid {
    grid-template-columns: 7fr 5fr;
    gap: 48px;
    align-items: start;
  }
  .page-about .about-cert__visual {
    align-items: flex-start;
  }
  .page-about .about-cert__img {
    aspect-ratio: auto;
  }

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

@media (min-width: 1024px) {
  .page-about .about-hero::before {
    font-size: 220px;
    right: 0;
  }
  .page-about .about-timeline__lead {
    font-size: 1.02rem;
  }
  .page-about .about-eco__card {
    padding: 28px 24px;
  }
}