/* Reset */
*, *::before, *::after { box-sizing: border-box; }
body {
  background: #f6f6f6;
  font-family: 'Prompt', 'Segoe UI', Arial, sans-serif;
  margin: 0;
  padding: 0;
  min-height: 100vh;
}
a { color: inherit; text-decoration: none; }
button, input, select, textarea { font-family: inherit; }
/* สีหลัก, font-size, utility class, ปุ่มหลัก */
.btn-main {
  background: #ffbc00;
  color: #23272f;
  border-radius: 6px;
  padding: 0.5rem 1.1rem;
  font-weight: bold;
  border: none;
  cursor: pointer;
}