/* ============================================================
   x402.ai — minimalist dark theme (Musk-style)
   ============================================================ */
:root{
  --bg:#0a0a0a;
  --bg-elev:#111111;
  --bg-elev2:#161616;
  --line:#222222;
  --text:#f5f5f5;
  --muted:#8a8a8a;
  --accent:#e8e8e8;
  --blue:#3b82f6;
  --radius:14px;
  --max:1080px;
  --font:-apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  --mono:"SF Mono",ui-monospace,Menlo,Consolas,monospace;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{
  background:var(--bg);color:var(--text);
  font-family:var(--font);line-height:1.6;
  font-size:17px;-webkit-font-smoothing:antialiased;
}
a{color:inherit;text-decoration:none}
.wrap{max-width:var(--max);margin:0 auto;padding:0 24px}
.muted{color:var(--muted)}
.mono{font-family:var(--mono)}

/* ---- Header ---- */
header.site{
  position:sticky;top:0;z-index:50;
  background:rgba(10,10,10,.72);backdrop-filter:blur(12px);
  border-bottom:1px solid var(--line);
}
.nav{display:flex;align-items:center;justify-content:space-between;height:64px}
.logo{font-weight:700;letter-spacing:-.02em;font-size:20px}
.logo b{color:var(--blue)}
.nav a.link{color:var(--muted);font-size:15px;margin-left:28px;transition:color .2s}
.nav a.link:hover{color:var(--text)}

/* ---- Hero ---- */
.hero{padding:120px 0 90px;text-align:center}
.hero .tag{
  display:inline-block;font-family:var(--mono);font-size:13px;
  color:var(--muted);border:1px solid var(--line);
  padding:6px 14px;border-radius:999px;margin-bottom:28px;
}
.hero h1{
  font-size:clamp(40px,7vw,76px);line-height:1.04;
  letter-spacing:-.03em;font-weight:700;margin-bottom:24px;
}
.hero h1 .dim{color:var(--muted)}
.hero p{max-width:620px;margin:0 auto 36px;font-size:19px;color:var(--muted)}
.cta{
  display:inline-flex;align-items:center;gap:8px;
  background:var(--text);color:#000;font-weight:600;
  padding:14px 26px;border-radius:999px;font-size:16px;
  transition:transform .15s,opacity .2s;
}
.cta:hover{transform:translateY(-2px);opacity:.9}
.cta.ghost{background:transparent;color:var(--text);border:1px solid var(--line)}

/* ---- Section ---- */
section.block{padding:84px 0;border-top:1px solid var(--line)}
.section-head{margin-bottom:48px;max-width:680px}
.section-head .kicker{font-family:var(--mono);color:var(--blue);font-size:13px;letter-spacing:.04em;text-transform:uppercase}
.section-head h2{font-size:clamp(28px,4vw,42px);letter-spacing:-.02em;margin:14px 0 12px;font-weight:700}
.section-head p{color:var(--muted);font-size:18px}

/* ---- Cards grid ---- */
.grid{display:grid;gap:20px;grid-template-columns:repeat(auto-fit,minmax(280px,1fr))}
.card{
  background:var(--bg-elev);border:1px solid var(--line);
  border-radius:var(--radius);padding:28px;transition:border-color .2s,transform .2s;
}
.card:hover{border-color:#333;transform:translateY(-3px)}
.card .num{font-family:var(--mono);color:var(--blue);font-size:14px;margin-bottom:14px}
.card h3{font-size:20px;margin-bottom:10px;letter-spacing:-.01em}
.card p{color:var(--muted);font-size:15px}

/* ---- Steps ---- */
.steps{counter-reset:step}
.step{
  display:flex;gap:22px;padding:26px 0;border-bottom:1px solid var(--line);
}
.step:last-child{border-bottom:0}
.step .idx{
  flex:0 0 44px;height:44px;border-radius:50%;
  border:1px solid var(--line);display:grid;place-items:center;
  font-family:var(--mono);color:var(--blue);font-weight:600;
}
.step .body h3{font-size:19px;margin-bottom:6px}
.step .body p{color:var(--muted);font-size:15px}
pre.code{
  background:var(--bg-elev2);border:1px solid var(--line);
  border-radius:10px;padding:16px 18px;overflow-x:auto;
  font-family:var(--mono);font-size:13.5px;color:#cfcfcf;margin-top:12px;
}

/* ---- Code inline ---- */
code.inl{font-family:var(--mono);background:var(--bg-elev2);padding:2px 7px;border-radius:6px;font-size:.9em;color:#dcdcdc}

/* ---- Soft pitch (bot) ---- */
.pitch{
  background:linear-gradient(180deg,var(--bg-elev),var(--bg));
  border:1px solid var(--line);border-radius:18px;
  padding:48px;text-align:center;
}
.pitch h2{font-size:clamp(26px,4vw,38px);letter-spacing:-.02em;margin-bottom:14px}
.pitch p{max-width:560px;margin:0 auto 28px;color:var(--muted);font-size:17px}

/* ---- Blog ---- */
.post{
  display:block;background:var(--bg-elev);border:1px solid var(--line);
  border-radius:var(--radius);padding:26px 28px;transition:border-color .2s,transform .2s;
}
.post:hover{border-color:#333;transform:translateY(-3px)}
.post .date{font-family:var(--mono);font-size:12px;color:var(--muted)}
.post h3{font-size:21px;margin:10px 0 8px;letter-spacing:-.01em}
.post p{color:var(--muted);font-size:15px}

/* ---- Article ---- */
.article{max-width:760px;margin:0 auto;padding:80px 24px}
.article h1{font-size:clamp(30px,5vw,48px);letter-spacing:-.02em;margin-bottom:14px}
.article .meta{color:var(--muted);font-family:var(--mono);font-size:13px;margin-bottom:36px}
.article h2{font-size:26px;margin:42px 0 14px;letter-spacing:-.01em}
.article p{margin-bottom:18px;color:#dcdcdc}
.article ul{margin:0 0 18px 22px;color:#dcdcdc}
.article li{margin-bottom:8px}
.article code{font-family:var(--mono);background:var(--bg-elev2);padding:2px 7px;border-radius:6px;font-size:.9em}

/* ---- AI widget ---- */
#ai-fab{
  position:fixed;right:22px;bottom:22px;z-index:100;
  background:var(--text);color:#000;font-weight:600;
  border:none;border-radius:999px;padding:14px 20px;font-size:15px;
  cursor:pointer;box-shadow:0 8px 30px rgba(0,0,0,.5);transition:transform .15s;
}
#ai-fab:hover{transform:translateY(-2px)}
#ai-panel{
  position:fixed;right:22px;bottom:80px;z-index:100;width:360px;max-width:92vw;
  background:var(--bg-elev);border:1px solid var(--line);border-radius:16px;
  overflow:hidden;display:none;flex-direction:column;height:520px;
  box-shadow:0 20px 60px rgba(0,0,0,.6);
}
#ai-panel.open{display:flex}
#ai-panel .ai-head{
  padding:16px 18px;border-bottom:1px solid var(--line);
  font-weight:600;display:flex;justify-content:space-between;align-items:center;
}
#ai-panel .ai-head button{background:none;border:none;color:var(--muted);font-size:20px;cursor:pointer}
#ai-msgs{flex:1;overflow-y:auto;padding:16px 18px;display:flex;flex-direction:column;gap:12px}
.msg{padding:10px 14px;border-radius:12px;font-size:14.5px;max-width:90%}
.msg.bot{background:var(--bg-elev2);align-self:flex-start}
.msg.me{background:var(--blue);color:#fff;align-self:flex-end}
#ai-input{display:flex;border-top:1px solid var(--line)}
#ai-input input{
  flex:1;background:var(--bg);border:none;color:var(--text);
  padding:14px 16px;font-size:14px;outline:none;font-family:var(--font);
}
#ai-input button{background:var(--text);color:#000;border:none;padding:0 18px;font-weight:600;cursor:pointer}

/* ---- Footer ---- */
footer.site{border-top:1px solid var(--line);padding:48px 0;color:var(--muted);font-size:14px}
footer.site .wrap{display:flex;justify-content:space-between;flex-wrap:wrap;gap:16px}
footer.site a{color:var(--muted)}
footer.site a:hover{color:var(--text)}

/* ---- Misc ---- */
.center{text-align:center}
.mt24{margin-top:24px}.mt40{margin-top:40px}
small.note{color:var(--muted);font-size:13px}

/* Logo image in header */
.logo{display:flex;align-items:center;gap:10px}
.logo-img{height:30px;width:30px;border-radius:7px;object-fit:cover;border:1px solid var(--line)}
.logo span{font-weight:700;letter-spacing:-.02em;font-size:20px}

/* Hero with logo art */
.hero-grid{display:grid;grid-template-columns:1.1fr .9fr;gap:48px;align-items:center;text-align:left}
.hero-text .tag{margin-bottom:24px}
.hero-text h1{font-size:54px;line-height:1.05;margin-bottom:24px}
.hero-text p{font-size:19px;color:var(--muted);max-width:none;margin-bottom:36px}
.hero-art{display:flex;justify-content:center;align-items:center}
.hero-logo{width:100%;max-width:360px;height:auto;border-radius:18px;border:1px solid var(--line);box-shadow:0 0 60px rgba(59,130,246,.15)}

/* Blog post images */
.article figure{margin:36px 0;padding:0}
.article figure img{width:100%;height:auto;border-radius:14px;border:1px solid var(--line);display:block;background:#0f0f0f}
.article figure figcaption{margin-top:12px;font-size:14px;color:var(--muted);text-align:center;line-height:1.4}
.article img.inline{width:100%;height:auto;border-radius:14px;border:1px solid var(--line);margin:32px 0;display:block}

@media(max-width:860px){
  .hero-grid{grid-template-columns:1fr;text-align:center;gap:32px}
  .hero-text h1{font-size:40px}
  .hero-art{order:-1}
  .hero-logo{max-width:220px}
  .logo{font-size:18px}
}