body {
  font-family: "Poppins", sans-serif;
  background: #f4f4f4;
  color: #333;
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
  margin: 0;
}

.hidden { display: none; }

.login-screen, .chat-screen {
  width: 400px;
  background: #fff;
  border-radius: 10px;
  box-shadow: 0 0 15px rgba(0,0,0,0.1);
  padding: 20px;
}

h1, h2 {
  text-align: center;
  color: #c0392b;
}

input, button {
  width: 100%;
  padding: 10px;
  margin-top: 10px;
  border-radius: 8px;
  border: 1px solid #ccc;
  font-size: 16px;
}

button {
  background-color: #c0392b;
  color: white;
  cursor: pointer;
}

button:hover {
  background-color: #a93226;
}

.messages {
  height: 300px;
  overflow-y: auto;
  border: 1px solid #ddd;
  padding: 10px;
  margin-bottom: 10px;
  background: #fafafa;
}

.message {
  padding: 6px;
  margin-bottom: 5px;
  border-bottom: 1px solid #eee;
}

.message span {
  font-weight: bold;
  color: #c0392b;
  cursor: pointer;
}

.footer {
  text-align: center;
  font-size: 12px;
  margin-top: 10px;
  color: #999;
}