:root{
  --bg:#f7f9fc;
  --bg2:#eef3ff;
  --text:#0b1220;
  --muted:#44506b;
  --border:rgba(15,23,42,.10);
  --accent:#0b3d91;
  --accent2:#6d28d9;
  --link:#0b3d91;
  --card:#ffffff;
  --shadow:0 14px 44px rgba(2,8,23,.10);
  --shadow2:0 6px 18px rgba(2,8,23,.08);
  --radius:14px;
}

/* Optional explicit dark theme (used by demo) */
.theme-dark{
  --bg:#070b14;
  --bg2:#0b1220;
  --text:#e7eefc;
  --muted:#9fb1d1;
  --border:rgba(231,238,252,.14);
  --accent:#7dd3fc;
  --accent2:#a78bfa;
  --link:#7dd3fc;
  --card:rgba(255,255,255,.06);
  --shadow:0 18px 56px rgba(0,0,0,.45);
  --shadow2:0 10px 28px rgba(0,0,0,.35);
}

*{box-sizing:border-box;}
html{scroll-behavior:smooth;}
body{
  margin:0;
  font-family:ui-sans-serif,system-ui,-apple-system,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  color:var(--text);
  line-height:1.65;
  -webkit-font-smoothing:antialiased;
  -moz-osx-font-smoothing:grayscale;
  overflow-x:hidden;
  background:
    radial-gradient(1100px 760px at 18% 5%, rgba(109,40,217,.14) 0%, transparent 60%),
    radial-gradient(900px 700px at 82% 15%, rgba(11,61,145,.14) 0%, transparent 60%),
    linear-gradient(180deg,var(--bg2) 0%,var(--bg) 48%);
  min-height:100vh;
}

/* Links */
a{color:var(--link);text-decoration:underline;text-underline-offset:2px;}
a:hover{text-decoration-thickness:2px;}
a:focus{outline:2px solid var(--accent);outline-offset:2px;}

/* Skip link */
.skip-link{
  position:absolute;
  left:-999px;
  top:12px;
  background:var(--card);
  color:var(--text);
  border:1px solid var(--border);
  padding:8px 12px;
  z-index:9999;
  text-decoration:none;
  border-radius:12px;
  box-shadow:var(--shadow2);
}
.skip-link:focus{left:12px;}

/* Containers */
.container{max-width:980px;margin:0 auto;padding:0 24px;}
@media (max-width:600px){.container{padding:0 16px;}}

/* Surfaces / cards */
.card{
  background:var(--card);
  border:1px solid var(--border);
  border-radius:var(--radius);
  box-shadow:var(--shadow2);
}

/* Buttons */
.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:10px;
  padding:11px 16px;
  border-radius:12px;
  font-size:15px;
  font-weight:650;
  text-decoration:none;
  border:1px solid rgba(0,0,0,.06);
  touch-action:manipulation;
  transition:transform .05s ease, box-shadow .15s ease, background .15s ease, border-color .15s ease;
  box-shadow:var(--shadow2);
  min-height:44px;
}
.btn.primary{
  background:linear-gradient(135deg,var(--accent) 0%,var(--accent2) 100%);
  color:#fff;
}
.btn.secondary{
  background:var(--card);
  color:var(--text);
  border-color:var(--border);
}
.btn:hover{transform:translateY(-1px);box-shadow:var(--shadow);}
.btn:focus,.btn:focus-visible{outline:2px solid var(--accent);outline-offset:2px;}

/* Form controls (base) */
input,select,textarea,button{font-family:inherit;}
button{
  border:none;
  background:linear-gradient(135deg,var(--accent) 0%,var(--accent2) 100%);
  color:#fff;
  border:1px solid rgba(0,0,0,.06);
  padding:10px 12px;
  border-radius:12px;
  cursor:pointer;
  font-weight:650;
  font-size:13px;
  touch-action:manipulation;
  box-shadow:var(--shadow2);
  transition:transform .05s ease, box-shadow .15s ease;
}
button:hover{transform:translateY(-1px);box-shadow:var(--shadow);}
button:focus{outline:2px solid var(--accent);outline-offset:2px;}
button.secondary{
  background:var(--card);
  color:var(--text);
  border-color:var(--border);
}