:root {
  --bg: #fafaf9;
  --surface: #fff;
  --border: #e8e6e1;
  --text: #1a1916;
  --text-dim: #6b6760;
}

* { box-sizing: border-box; margin: 0; padding: 0; }
body {
  background: var(--bg);
  color: var(--text);
  font-family: 'Geist', system-ui, sans-serif;
  font-size: 14px;
  min-height: 100dvh;
  max-width: 430px;
  margin: 0 auto;
  display: flex;
  flex-direction: column;
}
main { flex: 1; display: flex; flex-direction: column; padding: 24px; }
h1 { font-family: 'Instrument Serif', serif; font-size: 34px; font-weight: 400; }
hr { border: 0; border-top: 1px solid var(--border); margin: 8px 0; }
button {
  background: var(--text);
  color: #fff;
  border: none;
  border-radius: 10px;
  padding: 12px 20px;
  font-family: inherit;
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
}
button:disabled { opacity: 0.5; cursor: not-allowed; }
input {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 12px 14px;
  font-family: inherit;
  font-size: 14px;
  width: 100%;
}
.stack > * + * { margin-top: 12px; }
.muted { color: var(--text-dim); }