:root{
  --bg: #ffffff;
  --text: #111827;
  --muted: #6b7280;
  --primary: #2563eb;
  --card: #f8fafc;
  --radius: 10px;
}

[data-theme="dark"]{
  --bg: #0b1220;
  --text: #e6eef8;
  --muted: #9ca3af;
  --primary: #60a5fa;
  --card: #071127;
}

*{box-sizing:border-box}
html,body{height:100%}
body{
  margin:0;
  font-family: Inter, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial;
  background:var(--bg);
  color:var(--text);
  -webkit-font-smoothing:antialiased;
  line-height:1.5;
  scroll-behavior:smooth;
}

.container{max-width:1000px;margin:0 auto;padding:1rem}

.site-header{background:transparent;padding:0.5rem 0;border-bottom:1px solid rgba(0,0,0,0.04)}
.site-header .container{display:flex;align-items:center;gap:1rem}
.logo{margin:0;font-size:1.1rem}
.nav{margin-left:auto;display:flex;gap:0.75rem}
.nav a{color:var(--muted);text-decoration:none;padding:0.35rem 0.5rem;border-radius:6px}
.nav a:hover{color:var(--text);background:rgba(0,0,0,0.03)}
#theme-toggle{background:transparent;border:1px solid rgba(0,0,0,0.06);padding:0.35rem 0.6rem;border-radius:8px;cursor:pointer}

.hero{padding:3.5rem 0;text-align:center}
.hero h2{margin:0 0 0.5rem;font-size:1.8rem}
.hero p{color:var(--muted);max-width:60ch;margin:0.5rem auto}
.btn{display:inline-block;background:var(--primary);color:white;padding:0.6rem 1rem;border-radius:8px;text-decoration:none;border:none;cursor:pointer}
.btn.ghost{background:transparent;border:1px solid rgba(0,0,0,0.08);color:var(--text)}

.features{padding:2rem 0}
.features .grid{display:grid;grid-template-columns:repeat(3,1fr);gap:1rem}
.card{background:var(--card);padding:1rem;border-radius:var(--radius);box-shadow:0 1px 4px rgba(2,6,23,0.04)}

.contact{padding:2rem 0}
form{max-width:700px;margin:0 auto;display:flex;flex-direction:column;gap:0.5rem}
label{font-size:0.9rem;color:var(--muted)}
input,textarea{padding:0.65rem;border-radius:8px;border:1px solid rgba(0,0,0,0.08);background:transparent;color:var(--text)}
.form-actions{display:flex;gap:0.5rem;margin-top:0.5rem}
.status{color:var(--muted);margin-top:0.5rem}

.site-footer{padding:1.25rem 0;border-top:1px solid rgba(0,0,0,0.04);margin-top:2rem}

/* Responsive */
@media (max-width:800px){
  .features .grid{grid-template-columns:repeat(2,1fr)}
  .nav{display:none}
}
@media (max-width:520px){
  .features .grid{grid-template-columns:1fr}
  .hero h2{font-size:1.4rem}
}

/* small accessibility focus styles */
a:focus,button:focus,input:focus,textarea:focus{outline:3px solid color-mix(in srgb, var(--primary) 18%, transparent);outline-offset:2px}