* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 24px;
  background: #d9dadd;
}

.contact-us {
    display: flex;
    flex-direction: column;
    width: 100%;
    max-width: 900px;
    border-radius: 12px;
    padding: 18px;
    box-shadow: 0 6px 18px rgba(19, 24, 33, 0.06);
    background-color: #0f172a;
    color: #fff;
}

nav {
    display: flex;
    justify-content: space-between;
}

h2 {
    text-align: center;
    color: #fff;
    margin-bottom: 20px;
    font-size: 3rem;
}

.navigation {
  display: flex;
  padding: 20px;
  color: #fff;
  font-size: 20px;
}  

.navigation li {
  display: inline;
  margin: 5px;
  font-weight: bolder;
  text-decoration: none;
}

.navigation li a {
  color: #fff;
  text-decoration: none;
  cursor: pointer;
}

.navigation li a:hover {
  padding: 10px;
  border-radius: 8px;
  border: 2px solid #fff;
}

.intro {
    text-align: center;
    font-size: 18px;
    margin-bottom: 20px;
    line-height: 1.6;
}

h3 {
    font-size: 22px;
    color: #62cbee;
    margin: 15px auto 40px auto;
}

p {
    color: #ccc;
    line-height: 1.6;
    margin-bottom: 15px;
}

.details {
    margin-bottom: 15px;
    display: flex;
    flex-direction: column;
    border: 1px solid #fff;
    border-radius: 8px;
    padding: 30px;
}

#heading {
    color: #62cbee;
    margin-bottom: 10px;
}

input, textarea {
    background-color: #fff;
    outline: none;
    border-radius: 8px;
    padding: 12px;
    font-size: 16px;
    margin-top: 8px;
    border: none;
    width: 100%;
}

#btn{
    background-color: #62cbee;
    color: #fff;
    font-size: 18px;
    font-weight: bold;
    padding: 12px;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    width: 100%;
    margin-top: 12px;
}

.error-message, #message-error {
    color: #ff4d4f;
    margin-top: 8px;
    font-size: 18px;
}

.validation-message, i  {
    display: flex;
    color: #4BB543;
    margin-top: 8px;
    font-size: 18px;
}


/*  Responsiveness*/

@media (max-width: 375px) {
  nav {
    display: flex;
    flex-direction: column-reverse;
    align-items: center;
  }

  .navigation {
    display: flex;
    font-size: 15px;
    text-align: center;
  }

  h3 {
    font-size: 20px;
  }
}