body {
  font-family: Arial, sans-serif;
  margin: 20px;
}
h1, h2 {
  margin-bottom: 10px;
}
#login-screen, #panel {
  max-width: 600px;
  margin: auto;
}
input {
  padding: 8px;
  margin: 5px 0;
  width: 100%;
  box-sizing: border-box;
}
button {
  padding: 8px 16px;
  margin: 5px 0;
}
#messages {
  margin: 10px 0;
  background: #f9f9f9;
  padding: 10px;
  height: 300px;
  overflow-y: scroll;
}
#admin-panel {
  margin-top: 20px;
  border-top: 1px solid #ccc;
  padding-top: 10px;
}