:root{
--bg:#f7f7fb;
--card:#ffffff;
--accent:#2563eb;
--text:#0f172a;
--muted:#64748b;
--radius:12px;
}

/* Reset (velmi jednoduchý) */
*{box-sizing:border-box}
body{margin:0;font-family:system-ui,-apple-system,Segoe UI,Roboto,'Helvetica Neue',Arial;line-height:1.5;color:var(--text);background:var(--bg)}
.container{max-width:1000px;margin:0 auto;padding:1rem}

.site-header{background:linear-gradient(90deg, rgba(37,99,235,0.95), rgba(99,102,241,0.95));color:white}
.site-header .container{display:flex;align-items:center;justify-content:space-between;padding:1rem}
.logo{margin:0;font-size:1.25rem}
.main-nav a{color:rgba(255,255,255,0.95);text-decoration:none;margin-left:1rem}

.hero{padding:3rem 1rem;text-align:center}
.hero h2{margin:0 0 .5rem;font-size:1.75rem}
.hero p{color:var(--muted);margin:0 0 1rem}
.btn{display:inline-block;padding:.6rem 1rem;border-radius:999px;background:var(--accent);color:white;text-decoration:none;border:none;cursor:pointer}

.cards{display:grid;grid-template-columns:repeat(auto-fit,minmax(220px,1fr));gap:1rem;margin:2rem 0}
.card{background:var(--card);padding:1rem;border-radius:var(--radius);box-shadow:0 6px 18px rgba(15,23,42,0.06)}
.card h3{margin-top:0}

.contact{background:transparent;padding:1rem 0}
.contact-form{display:grid;gap:.6rem;max-width:520px}
.contact-form label{display:block;font-size:.9rem;color:var(--muted)}
.contact-form input,.contact-form textarea{width:100%;padding:.6rem;border:1px solid #e6eef8;border-radius:8px}

.site-footer{padding:1rem 0;color:var(--muted);text-align:center}

/* drobná responzivita */
@media (max-width:600px){
.site-header .container{flex-direction:column;gap:.6rem}
.main-nav a{margin-left:.5rem}
.hero{padding:2rem 1rem}
}

/* Přístupnost: focus stavy */
a:focus, button:focus, input:focus, textarea:focus{outline:3px solid rgba(37,99,235,0.25);outline-offset:2px}