* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: "Gill Sans", "Gill Sans MT", Calibri, "Trebuchet MS", sans-serif;
}

body {
  background: url(bg.jpg) center/cover fixed;
  min-height: 100vh;
  text-align: center;
  color: #3e51bd;
  display: grid;
  align-items: center;
  justify-items: center;
}

body .card {
  background: rgba(228, 229, 230, 0.88);
  padding: 30px;
  margin: 20px auto;
  min-width: 300px;
  width: 90%;
  max-width: 450px;
  border-radius: 30px;
  box-shadow: 0 4px 20px rgba(51, 51, 51, 0.25);
}

body .card div {
  margin: 20px 0 40px 0;
  font-size: 1.1rem;
  color: black;
}

body .card h2 {
  text-transform: uppercase;
}

body .card label {
  display: block;
  font-weight: 600;
  margin-top: 16px;
  margin-bottom: 4px;
}

body .card input {
  background: none;
  outline: none;
  border: 1px solid #3e51bd;
  margin: 6px 0;
  padding: 10px;
  border-radius: 10px;
  font-size: 1.15rem;
  width: 210px;
  text-align: center;
  transition: border-color 0.2s, box-shadow 0.2s;
}

body .card input:focus {
  border-color: #2c3e50;
  box-shadow: 0 0 0 3px rgba(62, 81, 189, 0.2);
}

body .card h3 {
  margin: 24px 20px 16px;
  font-size: 1.2rem;
}

body .card .btn {
  background: #3e51bd;
  border-radius: 20px;
  outline: 0;
  border: none;
  padding: 0.9rem 2rem;
  margin: 10px 0;
  color: white;
  font-size: 1.1rem;
  letter-spacing: 1px;
  cursor: pointer;
  transition: background 0.25s, transform 0.2s, opacity 0.2s;
  width: 100%;
  max-width: 210px;
}

body .card .btn:hover:not(:disabled) {
  background: #2c3e50;
  transform: scale(1.05);
}

body .card .btn:disabled {
  background: #4caf50;
  opacity: 0.9;
  cursor: default;
}