body {
  margin: 0;
  font-family: Arial, sans-serif;
  background: #f9f9f9;
}
header {
  background: #2c3e50;
}
nav ul {
  display: flex;
  justify-content: center;
  list-style: none;
  padding: 1rem;
  margin: 0;
}
nav li {
  margin: 0 1rem;
}
nav a {
  color: white;
  text-decoration: none;
  font-weight: bold;
}
main {
  padding: 2rem;
  max-width: 800px;
  margin: auto;
}
footer {
  background: #ecf0f1;
  padding: 1rem;
  text-align: center;
  margin-top: 2rem;
}
input, button, textarea {
  display: block;
  margin: 1rem 0;
  padding: 0.5rem;
  width: 100%;
  max-width: 400px;
}
img.profile-pic {
  width: 200px;
  border-radius: 10px;
  margin-bottom: 1rem;
}
@media (max-width: 768px) {
  nav ul {
    flex-direction: column;
    align-items: center;
  }
  img.profile-pic {
    width: 150px;
  }
}

.login-form {
  max-width: 400px;
  margin: 0 auto;
}
.error-msg {
  color: red;
  font-weight: bold;
  margin-top: 10px;
}