body {
  font-family: Arial, sans-serif;
  background: #121212;
  color: #e0e0e0;
  margin:0;
  padding:0;
  display:flex;
  height:100vh;
  box-sizing:border-box;
}

#sidebar {
  width:200px;
  background:#1e1e1e;
  padding:10px;
  display:flex;
  flex-direction:column;
  border-right:1px solid #333;
  overflow-y:auto;
}

#sidebar h3 { margin-top:0; }
#sidebar input { padding:5px; border-radius:6px; border:none; margin-bottom:10px; }

.userItem {
  padding:6px 10px;
  margin-bottom:2px;
  border-radius:6px;
  cursor:pointer;
}
.userItem:hover { background-color:#333; }

#chatContainer {
  flex:1;
  display:flex;
  flex-direction:column;
  padding:10px;
}

#login, #chat {
  background: #1e1e1e;
  border-radius:12px;
  padding:20px;
  margin-bottom:10px;
}

#messages {
  border:1px solid #333;
  border-radius:8px;
  padding:10px;
  height:400px;
  overflow-y:auto;
  display:flex;
  flex-direction:column;
  margin-bottom:10px;
  background:#1a1a1a;
  scroll-behavior:smooth;
}

.message {
  margin:6px 0;
  padding:10px 14px;
  border-radius:16px;
  max-width:75%;
  word-wrap:break-word;
  font-size:16px;
}

.me { background:#3a76f0; color:white; align-self:flex-end; }
.other { background:#2a2a2a; color:#e0e0e0; align-self:flex-start; }

.input-container { display:flex; gap:5px; }
#messageInput { flex:1; padding:10px; border-radius:8px; border:1px solid #333; background:#121212; color:#e0e0e0; }
#sendBtn, #downloadNewKeyBtn { padding:10px 14px; border:none; background:#3a76f0; color:white; border-radius:8px; cursor:pointer; }

@media (max-width:700px) {
  #sidebar { display:none; }
  #chatContainer { flex:1; }
}