/* ====== Default (Desktop) ====== */
body {
  font-family: Arial, sans-serif;
  font-size: 16px;
  margin: 0;
  padding: 0;
  background-color: #f2f2f2;
}

.login-box {
  width: 300px;
  margin: 100px auto;
  padding: 25px;
  background: white;
  border-radius: 8px;
  box-shadow: 0 0 10px gray;
}

input[type="text"],
input[type="password"],
input[type="submit"] {
  width: 100%;
  padding: 10px;
  margin-top: 10px;
  box-sizing: border-box;
}

input[type="submit"] {
  background: #007bff;
  color: white;
  border: none;
  cursor: pointer;
}

input[type="submit"]:hover {
  background: #0056b3;
}

.error {
  color: red;
  margin-top: 10px;
  text-align: center;
}

/* ====== Tablet (600px to 1024px) ====== */
@media only screen and (min-width: 600px) and (max-width: 1024px) {
  body {
    font-size: 17px;
    background-color: #e0f7fa;
  }

  .login-box {
    width: 80%;
    max-width: 400px;
    margin: 80px auto;
  }
}

/* ====== Phone (max-width: 599px) ====== */
@media only screen and (max-width: 599px) {
  body {
    font-size: 14px;
    background-color: #fff3e0;
  }

  .login-box {
    width: 90%;
    margin: 60px auto;
    padding: 20px;
  }

  input[type="text"],
  input[type="password"],
  input[type="submit"] {
    font-size: 14px;
  }
}