body {
  margin: 0;
  padding: 0;
  font-family: Roboto, sans-serif;
  background-repeat: no-repeat;
  background-size: cover;
  background: linear-gradient(90deg, #f0f2f5, #2b2929);
  height: 100vh;
  overflow: hidden;
  display: flex;
  justify-content: center;
  align-items: center;
}

.container {
  width: 100%;
  height: 100%;
  display: flex;
  justify-content: center;
  align-items: center;
}

.center {
  width: 90vw;
  max-width: 400px;
  background: white;
  border-radius: 10px;
  padding: 20px;
  box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
}

.center h1 {
  text-align: center;
  padding: 0 0 20px 0;
  border-bottom: 1px solid silver;
  font-size: 24px;
}

.center form {
  padding: 20px;
  box-sizing: border-box;
}

form .txt_field {
  position: relative;
  border-bottom: 2px solid #adadad;
  margin: 20px 0;
}

.txt_field input {
  width: 100%;
  padding: 5px;
  height: 40px;
  font-size: 16px;
  border: none;
  background: none;
  outline: none;
}

.txt_field label {
  position: absolute;
  top: 50%;
  left: 5px;
  color: #adadad;
  transform: translateY(-50%);
  font-size: 16px;
  pointer-events: none;
  transition: 0.3s;
}

.txt_field span::before {
  content: '';
  position: absolute;
  top: 40px;
  left: 0;
  width: 0;
  height: 2px;
  background: #2691d9;
  transition: 0.5s;
}

.txt_field input:focus ~ label,
.txt_field input:valid ~ label {
  top: -10px;
  font-size: 12px;
  color: #2691d9;
}

.txt_field input:focus ~ span::before,
.txt_field input:valid ~ span::before {
  width: 100%;
}

.pass {
  margin: -5px 0 20px 5px;
  color: #a6a6a6;
  cursor: pointer;
  font-size: 14px;
  text-align: right;
}

.pass:hover {
  text-decoration: underline;
}

input[type="Submit"] {
  width: 100%;
  height: 50px;
  border: 1px solid;
  border-radius: 25px;
  font-size: 18px;
  font-weight: 700;
  cursor: pointer;
  background: #2691d9;
  color: white;
  transition: 0.5s;
}

input[type="Submit"]:hover {
  background: #1b6cb7;
}

.signup_link {
  margin: 20px 0;
  text-align: center;
  font-size: 14px;
  color: #666666;
}

.signup_link a {
  color: #2691d9;
  text-decoration: none;
}

.signup_link a:hover {
  text-decoration: underline;
}

/* Mobile adjustments */
@media (max-width: 600px) {
  .center {
      width: 85vw;
      padding: 15px;
  }

  .center h1 {
      font-size: 22px;
  }

  .txt_field input {
      font-size: 14px;
      height: 35px;
  }

  input[type="Submit"] {
      font-size: 16px;
      height: 45px;
  }
}
form .txt_field {
  position: relative;
  margin: 20px 0;
  /* Remove the gray border */
  border-bottom: none;
}