header {
  display: flex;
  height: 90px;
  align-items: center;
  background-color: #0f172a;
  border-radius: 9px;
}

.header img {
  height: 200px;
}
.header nav {
  margin-left: 700px;
}

.header nav a {
  margin-left: 40px;
  text-decoration: none;
  color: white;
  position: relative;
}

nav a::after {
  content: "";
  position: absolute;
  left: 0;
  bottom: -3px;
  width: 0;
  height: 2px;
  background: gold;
  transition: width 0.3s ease;
}

nav a:hover::after {
  width: 100%;
}

body {
  background-image: url(../images/buycarbackground.png);
  background-size: cover;
  background-repeat: no-repeat;
}

.backtocars {
  margin-top: 20px;
}

.backtocars a {
  text-decoration: none;
  color: white;
  font-family: "Franklin Gothic Medium", "Arial Narrow", Arial, sans-serif;
}

.textsec {
  color: white;
  margin-left: 900px;
  margin-top: 70px;
}

.textsec h2 {
  font-family:
    "Trebuchet MS", "Lucida Sans Unicode", "Lucida Grande", "Lucida Sans",
    Arial, sans-serif;
  margin-bottom: 10px;
  font-size: xx-large;
}

.textsec p {
  font-family: Verdana, Geneva, Tahoma, sans-serif;
}

.formsec {
  border: 1px solid white;
  width: 450px;
  margin-left: 900px;
  height: 430px;
  border-radius: 9px;
  background-color: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(5px);
  display: flex;
  justify-content: center;
  align-items: center;
}

#name {
  background-color: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(5px);
  width: 400px;
  border: radius 15px;
  height: 50px;
  color: white;
  border: 1px solid white;
}

#phone {
  background-color: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(5px);
  width: 400px;
  border: radius 15px;
  height: 50px;
  color: white;
  border: 1px solid white;
}
#phone:focus,
#phone:valid,
#phone:invalid,
#phone:-webkit-autofill {
  background-color: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(5px);
}

#email {
  background-color: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(5px);
  width: 400px;
  border: radius 15px;
  height: 50px;
  color: white;
  border: 1px solid white;
}
#email:focus,
#email:valid,
#email:invalid,
#email:-webkit-autofill {
  background-color: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(5px);
}

#error {
  font-family: Verdana, Geneva, Tahoma, sans-serif;
  font-size: small;
}

#submit {
  background-color: gold;
  width: 400px;
  border: radius 15px;
  height: 50px;
  color: white;
  border: 1px solid white;
  cursor: pointer;
}