:root{
  --brand:#0b79d0;
  --muted:#6b7280;
  --bg:#f7fafc;
  --card:#ffffff;
}
*{box-sizing:border-box}
body{
  margin:0;
  font-family: Inter, system-ui, -apple-system, 'Segoe UI', Roboto, 'Helvetica Neue', Arial;
  background:var(--bg);
  color:#0f172a;
  -webkit-font-smoothing:antialiased;
}
.site-header{
  display:flex;
  justify-content:space-between;
  align-items:center;
  padding:18px 20px;
  background:linear-gradient(90deg,var(--brand),#0b6fbf);
  color:#fff;
}
.site-header .left h1{margin:0;font-size:1.25rem}
.site-header .left p{margin:6px 0 0;font-size:0.9rem;opacity:0.95}
.site-header .right{}
#lang-selector{
  font-size:1rem;
  padding:8px 10px;
  border-radius:8px;
  border:none;
  background:rgba(255,255,255,0.12);
  color:#fff;
  min-width:160px;
}
.info-bar{
  display:flex;
  gap:20px;
  justify-content:center;
  padding:12px 10px;
  background:transparent;
  color:var(--muted);
  font-size:0.95rem;
}
.info-item{background:var(--card);padding:8px 12px;border-radius:8px;box-shadow:0 1px 2px rgba(15,23,42,0.04);}
main{max-width:980px;margin:28px auto;padding:0 16px}
.welcome h2{margin:0 0 8px;font-size:1.15rem}
.instruction{margin:0 0 18px;color:var(--muted)}
.buttons{display:flex;gap:14px;flex-wrap:wrap;justify-content:center}
.primary{background:var(--brand);color:#fff;border:none;padding:14px 22px;border-radius:10px;font-size:1rem;cursor:pointer;box-shadow:0 6px 18px rgba(11,121,208,0.14)}
.primary:active{transform:translateY(1px)}
.site-footer{padding:18px;text-align:center;color:var(--muted);font-size:0.95rem}
/* overlay / fullscreen */
.overlay{
  position:fixed;top:0;left:0;width:100vw;height:100vh;z-index:9999;display:flex;align-items:center;justify-content:center;
}
.overlay .exit-hint{position:fixed;top:12px;left:12px;background:rgba(0,0,0,0.6);color:#fff;padding:8px 10px;border-radius:8px;font-size:14px;z-index:10001}
.overlay .top-tip{position:fixed;top:52px;left:12px;background:rgba(0,0,0,0.45);color:#fff;padding:6px 8px;border-radius:6px;font-size:13px;z-index:10001}
.visually-hidden{position:absolute!important;height:1px;width:1px;overflow:hidden;clip:rect(1px,1px,1px,1px);white-space:nowrap}
canvas{touch-action:none}