/* CSS chung */

body {
  background-color: #f2f2f2;
  font-family: Arial, sans-serif;
}

.container {
  max-width: 400px;
  margin: 100px auto;
  padding: 50px;
  background-color: #fff;
  border: 1px solid #ccc;
  border-radius: 4px;
}

h2 {
  text-align: center;
}

.form-group {
  margin-bottom: 10px;
}

label {
  display: block;
  font-weight: bold;
}

input[type="text"],
input[type="password"] {
  width: 100%;
  padding: 8px;
  border: 1px solid #ccc;
  border-radius: 4px;
}

input[type="submit"] {
  background-color: #4CAF50;
  color: #fff;
  border: none;
  padding: 10px 20px;
  border-radius: 4px;
  cursor: pointer;
  float: right;
}

input[type="submit"]:hover {
  background-color: #45a049;
}

/* CSS responsive */

@media only screen and (max-width: 480px) {
  .container {
    display: block;
    max-width: 600px;
    margin: 50px auto;
    padding: 30px;
  }

  input[type="submit"] {
    float: none;
    margin-top: 10px;
  }
}