:root{
  color-scheme: light dark;

  --bg:#ffffff;
  --fg:#0a0a0a;
  --muted:#4b5563;
  --border:#e5e7eb;
  --card:#ffffff;

  --btn:#0a0a0a;
  --btnText:#ffffff;

  --focus:#111827;
  --danger:#b91c1c;

  --radius:14px;
  --font: system-ui,-apple-system,Segoe UI,Roboto,Ubuntu,Helvetica,Arial,sans-serif;
}

:root[data-theme="dark"]{
  --bg:#0b0b0b;
  --fg:#f5f5f5;
  --muted:#a1a1aa;
  --border:#262626;
  --card:#101010;

  --btn:#f5f5f5;
  --btnText:#0b0b0b;

  --focus:#f5f5f5;
  --danger:#ef4444;
}

html,body{height:100%}
body{
  margin:0;
  font-family:var(--font);
  background:var(--bg);
  color:var(--fg);
  line-height:1.5;
  font-size:18px;
}

a{color:inherit}

.container{max-width:760px;margin:0 auto;padding:22px 18px}

.topbar{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-bottom:18px}
.brand{font-weight:800;letter-spacing:0.5px}

.card{background:var(--card);border:1px solid var(--border);border-radius:var(--radius);padding:16px}
.muted{color:var(--muted)}

button, .btn{
  appearance:none;
  border:1px solid var(--border);
  background:var(--btn);
  color:var(--btnText);
  border-radius:12px;
  padding:14px 16px;
  font-weight:750;
  font-size:18px;
  min-height:48px;
  cursor:pointer;
  text-decoration:none;
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:10px;
}

.btnSecondary{
  background:transparent;
  color:var(--fg);
}

input,select,textarea{
  width:100%;
  max-width:520px;
  padding:14px 14px;
  border-radius:12px;
  border:1px solid var(--border);
  background:transparent;
  color:var(--fg);
  font-size:18px;
}

label{display:block;margin:12px 0 6px}

:focus-visible{
  outline:3px solid var(--focus);
  outline-offset:2px;
}

.small{font-size:14px}
.h1{font-size:44px;letter-spacing:0.5px;margin:0 0 10px;line-height:1.1}
.sub{color:var(--muted);font-size:18px;margin:0 0 18px}