* { box-sizing: border-box; margin: 0; padding: 0; }
body { font-family: Arial, sans-serif; background-color: #f4f4f9; display: flex; justify-content: center; align-items: center; height: 100vh; }
.contenedor { background: white; padding: 40px; border-radius: 10px; box-shadow: 0 4px 15px rgba(0,0,0,0.1); width: 100%; max-width: 400px; text-align: center; }
h2 { margin-bottom: 20px; color: #333; }
.input-group { margin-bottom: 15px; text-align: left; }
.input-group label { display: block; margin-bottom: 5px; color: #666; font-weight: bold; font-size: 14px; }
.input-group input { width: 100%; padding: 10px; border: 1px solid #ccc; border-radius: 5px; font-size: 16px; }
button { width: 100%; padding: 12px; background-color: #007bff; color: white; border: none; border-radius: 5px; font-size: 16px; cursor: pointer; transition: background 0.3s; margin-top: 10px; font-weight: bold; }
button:hover { background-color: #0056b3; }
.error-msg { color: red; margin-top: 15px; font-size: 14px; min-height: 20px; }