:root{
  --bg:#f6f8fb;
  --card:#ffffff;
  --accent:#2563eb;
  --muted:#6b7280;
  --radius:12px;
  --shadow: 0 6px 18px rgba(16,24,40,0.08);
  font-family: Inter, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial;
}

*{box-sizing:border-box}
html,body{height:100%}
body{
  margin:0;
  background:linear-gradient(180deg,var(--bg),#eef2ff);
  color:#0f172a;
  display:flex;
  flex-direction:column;
  min-height:100vh;
  align-items:center;
}

.site-header{
  text-align:center;
  padding:48px 16px 8px;
}
.site-header h1{margin:0;font-size:2.25rem}
.tagline{color:var(--muted);margin-top:8px}

.content{
  width:100%;
  max-width:900px;
  padding:24px;
  display:grid;
  gap:20px;
  align-items:start;
}

.hero{
  background:var(--card);
  border-radius:var(--radius);
  padding:20px;
  box-shadow:var(--shadow);
}

.ad-container{
  background:var(--card);
  border-radius:var(--radius);
  padding:16px;
  box-shadow:var(--shadow);
  display:flex;
  justify-content:center;
  align-items:center;
  min-height:90px;
}

.interactive{
  background:var(--card);
  border-radius:var(--radius);
  padding:16px;
  box-shadow:var(--shadow);
  display:flex;
  gap:12px;
  align-items:center;
}

button{
  background:var(--accent);
  color:white;
  border:0;
  padding:10px 14px;
  border-radius:8px;
  cursor:pointer;
  font-weight:600;
}
button:active{transform:translateY(1px)}
.output{color:var(--muted)}

.site-footer{
  margin-top:auto;
  padding:18px 12px;
  color:var(--muted);
  text-align:center;
  width:100%;
}