style.css

/* Basic reset */
* {
  box-sizing: border-box;
}

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background: linear-gradient(135deg, #6b73ff, #000dff);
  height: 100vh;
  margin: 0;
  display: flex;
  justify-content: center;
  align-items: center;
  color: #fff;
}

.container {
  background: rgba(255, 255, 255, 0.1);
  padding: 30px 40px;
  border-radius: 15px;
  width: 100%;
  max-width: 400px;
  box-shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.37);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border: 1px solid rgba(255, 255, 255, 0.18);
  text-align: center;
}

h2 {
  margin-bottom: 25px;
  font-weight: 700;
  letter-spacing: 1px;
}

input {
  width: 100%;
  padding: 12px 15px;
  margin: 10px 0;
  border-radius: 8px;
  border: none;
  outline: none;
  font-size: 16px;
  transition: background-color 0.3s ease;
}

input:focus {
  background-color: rgba(255, 255, 255, 0.2);
}

button {
  width: 100%;
  padding: 12px 15px;
  margin-top: 15px;
  background-color: #3a3cff;
  border: none;
  border-radius: 8px;
  color: white;
  font-weight: 600;
  font-size: 18px;
  cursor: pointer;
  transition: background-color 0.3s ease;
}

button:hover {
  background-color: #2222ff;
}

#signupMessage, #loginMessage {
  margin-top: 15px;
  font-weight: 600;
}

.switch-page {
  margin-top: 20px;
  font-size: 14px;
  color: #ddd;
}

.switch-page a {
  color: #a6c1ff;
  text-decoration: none;
  font-weight: 600;
}

.switch-page a:hover {
  text-decoration: underline;
}