*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

body {
  min-height: 100dvh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 1rem;
  background: #111;
  color: #fff;
  font-family: sans-serif;
  padding: 2rem;
}

h1 {
  font-size: 2rem;
  font-weight: bold;
  letter-spacing: 0.04em;
  margin-bottom: 1rem;
}

.btn {
  display: block;
  width: 100%;
  max-width: 320px;
  padding: 1.1rem 1.5rem;
  font-size: 1.1rem;
  font-weight: 600;
  text-align: center;
  text-decoration: none;
  border-radius: 8px;
  touch-action: manipulation;
  transition: filter 0.15s;
}

.btn:active { filter: brightness(0.85); }

.btn-primary {
  background: #2ecc71;
  color: #000;
}

.btn-secondary {
  background: #2980b9;
  color: #fff;
}