/* ========== 爱思助手 站点样式 ========== */
*,*::before,*::after{box-sizing:border-box}
:root{
  --blue:#1a7cff;
  --blue-dark:#0a5ce0;
  --blue-light:#e8f1ff;
  --ink:#1f2733;
  --gray:#6b7585;
  --line:#e7ebf1;
  --bg:#f5f8fc;
  --radius:14px;
  --shadow:0 8px 28px rgba(26,124,255,.10);
  --wrap:1200px;
}
html{scroll-behavior:smooth}
body{
  margin:0;font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","PingFang SC","Microsoft YaHei","Hiragino Sans GB",sans-serif;
  color:var(--ink);background:var(--bg);line-height:1.7;font-size:15px;-webkit-font-smoothing:antialiased;
}
a{color:inherit;text-decoration:none}
img{max-width:100%;display:block}
.wrapper{max-width:var(--wrap);margin:0 auto;padding:0 20px}
h1,h2,h3,h4{margin:0;font-weight:700;line-height:1.35}

/* ---------- Header ---------- */
header{position:sticky;top:0;z-index:50;background:rgba(255,255,255,.92);backdrop-filter:blur(10px);border-bottom:1px solid var(--line)}
header .wrapper{display:flex;align-items:center;justify-content:space-between;height:66px}
.logo img{height:38px}
.logo a{display:flex;align-items:center;gap:8px;font-weight:800;font-size:20px;color:var(--blue)}
.nav{display:flex;gap:6px}
.nav a{padding:8px 18px;border-radius:999px;font-weight:600;color:var(--ink);transition:.2s}
.nav a:hover,.nav a.active{background:var(--blue);color:#fff}
.burger{display:none;flex-direction:column;gap:5px;background:none;border:0;cursor:pointer;padding:8px}
.burger span{width:24px;height:2px;background:var(--ink);border-radius:2px}

/* ---------- Hero ---------- */
.hero{background:linear-gradient(135deg,#0b63ff 0%,#2a8bff 45%,#5eb0ff 100%);color:#fff;position:relative;overflow:hidden}
.hero::after{content:"";position:absolute;right:-120px;top:-120px;width:420px;height:420px;background:radial-gradient(circle,rgba(255,255,255,.18),transparent 70%);border-radius:50%}
.hero .wrapper{display:grid;grid-template-columns:1.05fr .95fr;gap:30px;align-items:center;padding-top:56px;padding-bottom:56px;position:relative;z-index:2}
.hero h1{font-size:40px;line-height:1.25;letter-spacing:.5px}
.hero .lead{margin:18px 0 26px;font-size:17px;opacity:.94;max-width:520px}
.hero .ver{margin-top:18px;font-size:13px;opacity:.85}
.hero .ver span{opacity:.6;margin:0 6px}
.btns{display:flex;gap:14px;flex-wrap:wrap}
.btn{display:inline-flex;align-items:center;gap:8px;background:#fff;color:var(--blue-dark);font-weight:700;padding:14px 26px;border-radius:999px;box-shadow:0 6px 18px rgba(0,0,0,.15);transition:.2s}
.btn:hover{transform:translateY(-2px);box-shadow:0 10px 24px rgba(0,0,0,.22)}
.btn.ghost{background:rgba(255,255,255,.15);color:#fff;border:1px solid rgba(255,255,255,.55)}
.btn.ghost:hover{background:rgba(255,255,255,.25)}
.hero-art{display:flex;justify-content:center}
.hero-art img{max-width:100%;filter:drop-shadow(0 20px 40px rgba(0,0,0,.25))}

/* ---------- Section heads ---------- */
.sec{padding:64px 0}
.sec-alt{background:#fff}
.sec-head{text-align:center;margin-bottom:42px}
.sec-head h1,.sec-head h2{font-size:30px}
.sec-head p{margin:10px 0 0;color:var(--gray);text-transform:uppercase;letter-spacing:2px;font-size:12px}

/* ---------- Product cards ---------- */
.cards{display:grid;grid-template-columns:repeat(3,1fr);gap:24px}
.card{background:#fff;border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;display:flex;flex-direction:column;transition:.25s}
.card:hover{transform:translateY(-6px);box-shadow:var(--shadow);border-color:#cfe1ff}
.card .cover{background:linear-gradient(135deg,#eef4ff,#f6faff);padding:26px;text-align:center}
.card .cover img{margin:0 auto;max-height:150px;width:auto}
.card-body{padding:22px;display:flex;flex-direction:column;flex:1}
.card-title{display:flex;align-items:center;gap:12px;margin-bottom:14px}
.card-title img{height:42px;width:42px;border-radius:10px}
.card-title h3{font-size:18px}
.card-title small{color:var(--gray);font-weight:500;font-size:12px}
.feat{list-style:none;padding:0;margin:0 0 18px;flex:1}
.feat li{position:relative;padding-left:22px;margin-bottom:9px;color:#48515f;font-size:14px}
.feat li::before{content:"✓";position:absolute;left:0;color:var(--blue);font-weight:800}
.dl-row{display:flex;gap:10px;flex-wrap:wrap}
.dl{flex:1;min-width:90px;text-align:center;padding:10px;border-radius:10px;background:var(--blue-light);color:var(--blue-dark);font-weight:700;font-size:13px;transition:.2s}
.dl:hover{background:var(--blue);color:#fff}

/* ---------- Feature grid ---------- */
.fgrid{display:grid;grid-template-columns:repeat(4,1fr);gap:20px}
.fitem{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:26px 22px;transition:.25s}
.fitem:hover{box-shadow:var(--shadow);transform:translateY(-4px)}
.fitem .ic{width:50px;height:50px;border-radius:12px;background:var(--blue-light);color:var(--blue);display:flex;align-items:center;justify-content:center;font-size:24px;margin-bottom:14px}
.fitem h3{font-size:16px;margin-bottom:8px}
.fitem p{margin:0;color:var(--gray);font-size:13.5px}

/* ---------- News ---------- */
.news{display:grid;grid-template-columns:2fr 1fr;gap:28px}
.news-main{display:grid;grid-template-columns:1fr 1fr;gap:18px}
.n-card{background:#fff;border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;transition:.25s;display:flex;flex-direction:column}
.n-card:hover{box-shadow:var(--shadow);transform:translateY(-4px)}
.n-cover{height:150px;background:linear-gradient(135deg,#dbe9ff,#eef5ff);background-size:cover;background-position:center}
.n-info{padding:16px}
.n-info h3{font-size:15.5px;margin-bottom:8px;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.n-info p{margin:0 0 12px;color:var(--gray);font-size:13px;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.n-meta{display:flex;justify-content:space-between;font-size:12px;color:#9aa3b1}
.n-meta .tag{color:var(--blue);font-weight:600}
.news-side{display:flex;flex-direction:column;gap:14px}
.s-item{background:#fff;border:1px solid var(--line);border-radius:10px;padding:14px 16px;transition:.2s}
.s-item:hover{border-color:#cfe1ff;background:var(--blue-light)}
.s-item h3{font-size:14.5px;font-weight:600}
.s-item span{font-size:12px;color:#9aa3b1}

/* ---------- FAQ ---------- */
.faq{max-width:880px;margin:0 auto}
.faq details{background:#fff;border:1px solid var(--line);border-radius:12px;margin-bottom:14px;padding:4px 20px}
.faq summary{cursor:pointer;font-weight:700;padding:16px 0;list-style:none;display:flex;justify-content:space-between;align-items:center}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:"+";color:var(--blue);font-size:22px;font-weight:400}
.faq details[open] summary::after{content:"−"}
.faq p{margin:0 0 18px;color:#48515f}

/* ---------- Article ---------- */
.article{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:38px 44px;max-width:860px;margin:0 auto}
.article h1{font-size:28px;margin-bottom:12px}
.article .a-meta{color:#9aa3b1;font-size:13px;margin-bottom:24px;border-bottom:1px solid var(--line);padding-bottom:16px}
.article h2{font-size:20px;margin:28px 0 12px;padding-left:12px;border-left:4px solid var(--blue)}
.article p{margin:0 0 16px;color:#39414f}
.article ul,.article ol{color:#39414f;padding-left:22px}
.article li{margin-bottom:8px}
.crumb{font-size:13px;color:var(--gray);margin-bottom:18px}
.crumb a:hover{color:var(--blue)}

/* ---------- List page ---------- */
.post-list{display:grid;grid-template-columns:repeat(2,1fr);gap:20px}
.intro{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:30px 34px;margin-bottom:40px}
.intro h1{font-size:26px;margin-bottom:14px}
.intro p{color:#48515f;margin:0 0 12px}

/* ---------- Footer ---------- */
footer{background:#0f1b2d;color:#aeb8c6;padding:48px 0 28px;margin-top:20px}
.f-top{display:grid;grid-template-columns:1.5fr 1fr 1fr;gap:30px}
.f-top h4{color:#fff;font-size:16px;margin-bottom:16px}
.f-top a{color:#aeb8c6;font-size:13.5px;line-height:2.1;transition:.2s}
.f-top a:hover{color:#fff}
.f-links{display:flex;flex-direction:column}
.f-desc{font-size:13px;line-height:1.9;max-width:340px}
.f-brand{display:flex;align-items:center;gap:10px;margin:18px 0;color:#fff;font-weight:600}
.f-bottom{border-top:1px solid rgba(255,255,255,.12);margin-top:30px;padding-top:20px;font-size:12.5px;color:#7c8799;line-height:2}
.f-bottom a{color:#7c8799}
.f-bottom a:hover{color:#aeb8c6}

/* ---------- Responsive ---------- */
@media(max-width:900px){
  .hero .wrapper{grid-template-columns:1fr;text-align:center}
  .hero .lead{margin-left:auto;margin-right:auto}
  .btns{justify-content:center}
  .hero-art{order:-1}
  .cards,.fgrid{grid-template-columns:1fr 1fr}
  .news{grid-template-columns:1fr}
  .post-list{grid-template-columns:1fr}
  .f-top{grid-template-columns:1fr}
}
@media(max-width:560px){
  .nav{display:none;position:absolute;top:66px;left:0;right:0;background:#fff;flex-direction:column;border-bottom:1px solid var(--line);padding:10px 20px}
  .nav.open{display:flex}
  .burger{display:flex}
  .hero h1{font-size:30px}
  .cards,.fgrid,.news-main{grid-template-columns:1fr}
  .article{padding:26px 20px}
}