/* ============================================================
   page-about.css · 关于平台 · 品牌故事长卷粘性目录
   母题：荷叶舒展 + 左侧粘性目录 + 右侧长卷
   ============================================================ */

/* ---------- 首屏 ---------- */
.ab-hero{
  position:relative;overflow:hidden;
  padding:140px 0 70px;
  background:linear-gradient(180deg,#f6fafe 0%,#ffffff 80%);
}
.ab-hero-glow{
  position:absolute;border-radius:50%;filter:blur(60px);opacity:.55;pointer-events:none;
}
.ab-glow-1{width:420px;height:420px;background:radial-gradient(circle,#bcdcf5,transparent 70%);top:-120px;right:-80px;}
.ab-glow-2{width:360px;height:360px;background:radial-gradient(circle,#dcd4f5,transparent 70%);bottom:-100px;left:-60px;}
.ab-hero-inner{position:relative}
.ab-hero-text{max-width:780px;margin-bottom:40px}
.ab-hero-title{
  font-size:clamp(1.9rem,3.6vw,2.8rem);font-weight:800;line-height:1.35;letter-spacing:.5px;margin:18px 0 18px;
}
.ab-hero-title em{font-style:normal;background:linear-gradient(120deg,var(--blue),var(--purple));-webkit-background-clip:text;background-clip:text;-webkit-text-fill-color:transparent;}
.ab-hero-sub{color:var(--ink-2);font-size:1.05rem;max-width:620px}
.ab-hero-cta{display:flex;flex-wrap:wrap;gap:14px;margin-top:28px}
.ab-hero-figure{
  border-radius:var(--r-lg) var(--r-sm) var(--r-lg) var(--r-sm);
  overflow:hidden;box-shadow:var(--shadow-2);
}
.ab-hero-figure img{aspect-ratio:16/9;object-fit:cover;width:100%}

/* ---------- 故事长卷：粘性目录 + 正文 ---------- */
.ab-story{padding-top:60px}
.ab-story-layout{
  display:grid;grid-template-columns:240px 1fr;gap:48px;align-items:flex-start;
}
.ab-toc{
  position:sticky;top:100px;
  background:#fff;border:1px solid var(--line);padding:24px 22px;
  border-radius:var(--r-lg) var(--r-sm) var(--r-lg) var(--r-sm);
  box-shadow:var(--shadow);
}
.ab-toc h3{font-size:1rem;margin-bottom:14px;color:var(--ink)}
.ab-toc ul li{margin-bottom:4px}
.ab-toc a{
  display:block;padding:9px 12px;border-radius:10px;
  color:var(--ink-2);font-size:.92rem;border-left:3px solid transparent;
  transition:all .25s;
}
.ab-toc a:hover{color:var(--blue);background:var(--blue-bg);border-left-color:var(--blue)}

.ab-scroll{max-width:780px}
.ab-chapter{
  padding:36px 0;border-bottom:1px dashed var(--line);
  scroll-margin-top:100px;
}
.ab-chapter:last-child{border-bottom:none}
.ab-chapter-no{
  display:inline-block;font-size:.85rem;font-weight:800;letter-spacing:2px;
  color:var(--purple);background:var(--purple-bg);
  padding:4px 12px;border-radius:999px;margin-bottom:14px;
}
.ab-chapter h2{font-size:1.6rem;margin-bottom:16px;line-height:1.4}
.ab-chapter p{color:var(--ink-2);margin-bottom:14px;line-height:1.9;font-size:1rem}
.ab-chapter p b{color:var(--ink)}
.ab-chapter a{color:var(--blue);text-decoration:underline;text-underline-offset:3px}
.ab-chapter-figure{
  margin:18px 0 22px;border-radius:var(--r-lg) var(--r-sm) var(--r-lg) var(--r-sm);
  overflow:hidden;box-shadow:var(--shadow);
}
.ab-chapter-figure img{aspect-ratio:3/2;object-fit:cover;width:100%}
.ab-no-list{padding-left:0;display:grid;gap:10px}
.ab-no-list li{
  position:relative;padding:12px 14px 12px 38px;
  background:var(--blue-bg);border-radius:var(--r-sm);
  color:var(--ink-2);font-size:.95rem;
}
.ab-no-list li::before{
  content:"×";position:absolute;left:14px;top:10px;
  color:#d8646b;font-weight:800;
}

/* ---------- 平台能帮你 ---------- */
.ab-help-section{background:var(--mix-bg)}
.ab-help-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:22px}
.ab-help-card{
  background:#fff;border:1px solid var(--line);padding:28px 22px;
  border-radius:var(--r-lg) var(--r-sm) var(--r-lg) var(--r-sm);
  box-shadow:var(--shadow);transition:transform .3s,box-shadow .3s;
  display:block;
}
.ab-help-card:hover{transform:translateY(-6px);box-shadow:var(--shadow-2)}
.ab-help-ico{
  width:46px;height:46px;border-radius:14px;display:flex;align-items:center;justify-content:center;
  background:var(--purple-bg);color:var(--purple);margin-bottom:16px;
}
.ab-help-ico svg{width:24px;height:24px}
.ab-help-card h3{font-size:1.05rem;margin-bottom:10px}
.ab-help-card p{color:var(--ink-2);font-size:.92rem;line-height:1.8}

/* ---------- FAQ ---------- */
.ab-faq-list{max-width:820px;margin:0 auto;display:grid;gap:14px}
.ab-faq{
  background:#fff;border:1px solid var(--line);border-radius:var(--r-md);
  padding:18px 22px;transition:box-shadow .3s;
}
.ab-faq[open]{box-shadow:var(--shadow)}
.ab-faq summary{
  cursor:pointer;font-weight:600;list-style:none;display:flex;justify-content:space-between;align-items:center;
}
.ab-faq summary::-webkit-details-marker{display:none}
.ab-faq summary::after{content:"+";color:var(--blue);font-size:1.3rem;font-weight:400}
.ab-faq[open] summary::after{content:"–"}
.ab-faq p{color:var(--ink-2);margin-top:12px;line-height:1.85}
.ab-faq p a{color:var(--blue);text-decoration:underline}
.ab-faq-more{text-align:center;margin-top:26px;color:var(--ink-2)}
.ab-faq-more a{color:var(--blue);font-weight:600}

/* ---------- 资讯 ---------- */
.ab-news-section{background:#fff}
.ab-news-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:20px}
.ab-news-card{
  background:#fff;border:1px solid var(--line);border-radius:var(--r-md);
  overflow:hidden;box-shadow:var(--shadow);transition:transform .3s,box-shadow .3s;
  display:flex;flex-direction:column;
}
.ab-news-card:hover{transform:translateY(-6px);box-shadow:var(--shadow-2)}
.ab-news-card img{aspect-ratio:3/2;object-fit:cover;width:100%}
.ab-news-body{padding:16px 16px 20px}
.ab-news-body h3{font-size:.98rem;margin:10px 0 8px;line-height:1.5}
.ab-news-body p{color:var(--ink-3);font-size:.85rem;line-height:1.7}
.ab-news-more{text-align:center;margin-top:28px}
.ab-news-more a{color:var(--blue);font-weight:600}

/* ---------- 关于我们其他页 ---------- */
.ab-other-section{background:var(--blue-bg)}
.ab-other-grid{
  display:grid;grid-template-columns:repeat(3,1fr);gap:16px;max-width:880px;margin:0 auto;
}
.ab-other-card{
  background:#fff;border:1px solid var(--line);padding:22px 18px;text-align:center;
  border-radius:var(--r-md);font-weight:600;color:var(--ink-2);
  transition:all .25s;box-shadow:var(--shadow);
}
.ab-other-card:hover{color:var(--blue);border-color:var(--blue);transform:translateY(-4px);box-shadow:var(--shadow-2)}

/* ---------- 底部 CTA ---------- */
.ab-cta{
  position:relative;overflow:hidden;padding:90px 0;
  background:linear-gradient(135deg,var(--blue) 0%,var(--purple) 100%);color:#fff;
}
.ab-cta-glow{
  position:absolute;width:400px;height:400px;border-radius:50%;
  background:radial-gradient(circle,rgba(255,255,255,.35),transparent 70%);
  top:-160px;right:-100px;
}
.ab-cta-inner{position:relative;text-align:center;max-width:720px}
.ab-cta-inner h2{font-size:clamp(1.6rem,3vw,2.3rem);margin-bottom:14px}
.ab-cta-inner p{opacity:.92;margin-bottom:24px}
.ab-cta-contact{display:flex;flex-wrap:wrap;justify-content:center;gap:22px;margin-bottom:26px}
.ab-cta-line{
  display:inline-flex;align-items:center;gap:8px;font-weight:600;
  background:rgba(255,255,255,.15);padding:10px 20px;border-radius:999px;
}
.ab-cta-line:hover{background:rgba(255,255,255,.28)}
.ab-cta-line .ico{width:18px;height:18px}
.ab-cta .btn-primary{background:#fff;color:var(--blue)}

/* ---------- 响应式 ---------- */
@media (max-width:1023px){
  .ab-story-layout{grid-template-columns:1fr;gap:28px}
  .ab-toc{position:static;order:-1}
  .ab-toc ul{display:flex;flex-wrap:wrap;gap:8px}
  .ab-toc a{border-left:none;padding:7px 12px;background:var(--blue-bg);border-radius:999px}
  .ab-help-grid{grid-template-columns:repeat(2,1fr)}
  .ab-news-grid{grid-template-columns:repeat(2,1fr)}
  .ab-other-grid{grid-template-columns:repeat(2,1fr)}
}
@media (max-width:767px){
  .ab-hero{padding:110px 0 50px}
  .ab-help-grid,.ab-news-grid,.ab-other-grid{grid-template-columns:1fr}
  .ab-how-grid{grid-template-columns:1fr}
}

/* ---------- 我们是怎么做科普的 ---------- */
.ab-how-section{background:var(--purple-bg)}
.ab-how-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:20px}
.ab-how-card{
  background:#fff;border:1px solid var(--line);padding:26px 22px;
  border-radius:var(--r-lg) var(--r-sm) var(--r-lg) var(--r-sm);
  box-shadow:var(--shadow);transition:transform .3s;
}
.ab-how-card:hover{transform:translateY(-4px)}
.ab-how-ico{
  width:44px;height:44px;border-radius:12px;display:flex;align-items:center;justify-content:center;
  background:var(--blue-bg);color:var(--blue);margin-bottom:14px;
}
.ab-how-ico svg{width:22px;height:22px}
.ab-how-card h3{font-size:1rem;margin-bottom:8px}
.ab-how-card p{color:var(--ink-2);font-size:.88rem;line-height:1.8}

.ab-how-body{
  max-width:880px;margin:30px auto 0;
  background:#fff;border:1px solid var(--line);padding:28px 30px;
  border-radius:var(--r-md);box-shadow:var(--shadow);
}
.ab-how-body p{color:var(--ink-2);line-height:2;font-size:.93rem;margin-bottom:12px}
.ab-how-body p:last-child{margin-bottom:0}

/* ---------- 写在最后 ---------- */
.ab-end-body{max-width:880px;margin:0 auto;text-align:center}
.ab-end-body p{color:var(--ink-2);line-height:2;font-size:.95rem;margin-bottom:14px}
.ab-end-body p:last-child{margin-bottom:0}

@media (max-width:1023px){
  .ab-how-grid{grid-template-columns:repeat(2,1fr)}
}