/* ============ AS AI TOOLS — clean, light blog ============ */
:root{
  --blue:#2563eb; --blue-d:#1d4ed8; --purple:#7c3aed;
  --ink:#1a2332; --muted:#5b6472; --bg:#eef2f6; --card:#fff;
  --line:#e2e8f0; --radius:14px; --shadow:0 8px 28px rgba(26,35,50,.07);
}
*{margin:0;padding:0;box-sizing:border-box}
html{scroll-behavior:smooth}
body{font-family:'Segoe UI',system-ui,-apple-system,Roboto,Arial,sans-serif;background:var(--bg);color:var(--ink);line-height:1.7}
img{max-width:100%;height:auto}
a{color:var(--blue);text-decoration:none}
a:hover{color:var(--blue-d)}
h1,h2,h3{line-height:1.3;color:var(--ink)}
.container{max-width:1180px;margin:0 auto;padding:0 20px}
.section{padding:56px 0}
.sec-head{text-align:center;margin-bottom:34px}
.sec-head h2{font-size:2rem;margin-bottom:6px}
.sec-head h2 span{color:var(--blue)}
.sec-head p{color:var(--muted)}
.btn{display:inline-block;padding:13px 30px;border-radius:50px;font-weight:700;border:0;cursor:pointer;transition:.25s}
.btn-blue{background:var(--blue);color:#fff;box-shadow:0 8px 22px rgba(37,99,235,.35)}
.btn-blue:hover{background:var(--blue-d);transform:translateY(-2px)}

/* ---- Header ---- */
.site-header{background:#fff;position:sticky;top:0;z-index:50;border-bottom:1px solid var(--line);box-shadow:0 2px 12px rgba(0,0,0,.04)}
.navbar{display:flex;align-items:center;justify-content:space-between;padding:14px 0;gap:14px}
.logo{font-size:1.6rem;font-weight:800;color:var(--ink);letter-spacing:-.5px}
.logo span{color:var(--blue)}
.custom-logo-link{display:inline-block;flex-shrink:0;line-height:0}
.custom-logo{max-height:52px;width:auto;max-width:210px}
.nav{display:flex;list-style:none;gap:4px;align-items:center}
.nav a{display:block;padding:10px 14px;color:#37415a;font-weight:600;border-radius:8px;white-space:nowrap;transition:.2s}
.nav a:hover{color:var(--blue);background:#eef4ff}
.nav li{position:relative}
.nav .sub-menu{display:none;position:absolute;top:100%;left:0;background:#fff;min-width:220px;border-radius:12px;box-shadow:var(--shadow);list-style:none;padding:8px;z-index:60;border:1px solid var(--line)}
.nav li:hover>.sub-menu{display:block}
.nav .sub-menu a{color:var(--ink);font-weight:500;font-size:.93rem;padding:10px 14px}
.nav .sub-menu a:hover{background:#eef4ff;color:var(--blue)}
.menu-toggle{display:none;background:none;border:0;color:var(--blue);font-size:1.8rem;cursor:pointer}

/* ---- Search ---- */
.searchbar{display:flex;max-width:560px;margin:0 auto;background:#fff;border-radius:50px;padding:6px;box-shadow:0 12px 30px rgba(37,99,235,.15);border:1px solid var(--line)}
.searchbar input{flex:1;border:0;background:none;padding:12px 20px;font-size:1rem;color:var(--ink);min-width:0}
.searchbar input:focus{outline:none}
.searchbar-mini{max-width:250px;padding:3px;margin:0;box-shadow:none}
.searchbar-mini input{padding:8px 14px;font-size:.88rem}

/* ---- Hero ---- */
.hero{background:linear-gradient(180deg,#ffffff 0%,#e8eef8 100%);padding:72px 0 60px;text-align:center}
.hero h1{font-size:clamp(2.1rem,5vw,3.2rem);margin-bottom:14px}
.hero h1 span{color:var(--blue)}
.hero p{color:var(--muted);max-width:640px;margin:0 auto 28px}
.hero-tags{margin-top:22px;display:flex;gap:10px;justify-content:center;flex-wrap:wrap}
.hero-tags a{border:1px solid #c7d7fd;color:var(--blue);padding:7px 18px;border-radius:30px;font-size:.88rem;transition:.25s;background:#fff}
.hero-tags a:hover{background:var(--blue);color:#fff}

/* ---- Article cards ---- */
.card-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:22px}
.acard{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;transition:.3s;box-shadow:var(--shadow);display:block}
.acard:hover{transform:translateY(-5px);box-shadow:0 18px 44px rgba(26,35,50,.13)}
.acard-img{height:200px;overflow:hidden;background:#dfe7f2}
.acard-img img{width:100%;height:100%;object-fit:cover;display:block;transition:transform .4s}
.acard:hover .acard-img img{transform:scale(1.04)}
.acard-body{padding:22px 24px}
.cat-label{display:inline-block;color:#fff;font-size:.74rem;font-weight:700;padding:4px 14px;border-radius:20px;margin-bottom:10px;letter-spacing:.3px}
.acard-body h3{font-size:1.15rem;margin-bottom:8px}
.acard-body p{color:var(--muted);font-size:.9rem;margin-bottom:14px}
.acard-meta{display:flex;justify-content:space-between;font-size:.8rem;color:var(--muted);border-top:1px dashed var(--line);padding-top:12px}
.read-more{margin-top:12px;font-size:.82rem;font-weight:700;color:var(--blue);letter-spacing:.4px}

/* ---- Pages / single ---- */
.page-hero{background:linear-gradient(180deg,#ffffff,#e8eef8);padding:48px 0}
.page-hero h1{font-size:2.2rem}
.page-hero p{color:var(--muted)}
.page-body{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:44px;margin:36px auto;max-width:840px;box-shadow:var(--shadow)}
.page-body h2{font-size:1.4rem;margin:26px 0 10px}
.page-body ul,.page-body ol{margin:8px 0 8px 22px}
.page-body li{margin-bottom:6px}
.article{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:44px;margin:36px auto;max-width:820px;box-shadow:var(--shadow)}
.article h1{font-size:2.1rem;margin:10px 0}
.article h2{font-size:1.5rem;margin:30px 0 12px;padding-bottom:8px;border-bottom:2px solid var(--blue)}
.article h3{font-size:1.25rem;margin:24px 0 10px}
.article p{margin-bottom:16px}
.article ul,.article ol{margin:10px 0 18px 22px}
.article li{margin-bottom:7px}
.article table{width:100%;border-collapse:collapse;margin:18px 0;font-size:.9rem;display:block;overflow-x:auto}
.article th,.article td{border:1px solid var(--line);padding:10px 12px;text-align:left}
.article th{background:#eef4ff}
.article blockquote{border-left:4px solid var(--blue);background:#eef4ff;padding:16px 20px;margin:18px 0;border-radius:0 10px 10px 0}
.article-img{margin:18px 0 24px;border-radius:12px;overflow:hidden}
.article-img img{width:100%;display:block}
.article-meta{color:var(--muted);font-size:.9rem;margin-bottom:8px}
.breadcrumb{font-size:.86rem;color:var(--muted);margin-bottom:16px}
.breadcrumb a{color:var(--blue)}

/* ---- Footer ---- */
.site-footer{background:#fff;color:var(--muted);padding:56px 0 0;margin-top:40px;border-top:1px solid var(--line)}
.foot-grid{display:grid;grid-template-columns:1.4fr 1fr 1fr;gap:30px;padding-bottom:38px}
.site-footer h4{color:var(--ink);margin-bottom:14px;font-size:1rem}
.site-footer ul{list-style:none}
.site-footer li{margin-bottom:9px}
.site-footer a{color:var(--muted)}
.site-footer a:hover{color:var(--blue)}
.foot-bottom{border-top:1px solid var(--line);padding:18px 0;text-align:center;font-size:.86rem}

/* ---- Misc ---- */
.pagination{margin-top:30px;text-align:center}
.pagination .page-numbers{display:inline-block;padding:9px 16px;border:1px solid var(--line);border-radius:8px;margin:0 3px;background:#fff;color:var(--ink)}
.pagination .current{background:var(--blue);color:#fff;border-color:var(--blue)}
.to-top{position:fixed;right:22px;bottom:22px;z-index:60;width:48px;height:48px;border-radius:50%;background:var(--blue);color:#fff;border:0;font-size:1.3rem;cursor:pointer;display:none}
.to-top.show{display:block}
.no-results{background:#fff;border:1px dashed var(--line);border-radius:var(--radius);padding:44px;text-align:center;color:var(--muted)}
.reveal{opacity:0;transform:translateY(30px);transition:opacity .7s ease,transform .7s ease}
.reveal.visible{opacity:1;transform:none}
.d1{transition-delay:.1s}.d2{transition-delay:.2s}

@media(max-width:960px){
  .card-grid{grid-template-columns:1fr 1fr}
  .foot-grid{grid-template-columns:1fr 1fr}
  .nav{display:none;position:absolute;top:100%;left:0;right:0;background:#fff;flex-direction:column;align-items:stretch;padding:12px;box-shadow:0 20px 40px rgba(0,0,0,.12);border-bottom:1px solid var(--line)}
  .nav.open{display:flex}
  .nav .sub-menu{position:static;box-shadow:none;background:transparent;border:0}
  .nav .sub-menu a{color:var(--ink)}
  .menu-toggle{display:block}
  .article{padding:28px 20px}
}
@media(max-width:640px){.card-grid{grid-template-columns:1fr}}