* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Segoe UI", sans-serif;
  background: #f3f4f6;
  height: 100vh;
  overflow: hidden;
}

/* ---------- LOGIN ---------- */
#login {
  max-width: 420px;
  margin: 120px auto;
  background: #fff;
  padding: 20px;
  border-radius: 10px;
  border: 1px solid #ddd;
}

#login input {
  width: 100%;
  padding: 10px 14px;
  margin-bottom: 10px;
  font-size: 16px;
}

#login button {
  width: 100%;
  padding: 10px;
  background: #333;
  color: #fff;
  border: none;
  border-radius: 6px;
  cursor: pointer;
}

/* ---------- LAYOUT ---------- */
#layout {
  display: flex;
  height: 100vh;
}

/* ---------- SIDEBAR ---------- */
#sidebar {
  width: 320px;
  background: #ffffff;
  border-right: 1px solid #ddd;
  display: flex;
  flex-direction: column;
}

.sidebar-header {
  padding: 14px 16px;
  font-weight: bold;
  border-bottom: 1px solid #eee;
}

#list {
  flex: 1;
  overflow-y: auto;
}

.chat-item {
  padding: 12px 16px;
  cursor: pointer;
  border-bottom: 1px solid #f0f0f0;
}

.chat-item:hover {
  background: #f5f5f5;
}

.chat-item.active {
  background: #e9eefb;
}

/* ---------- CHAT PANEL ---------- */
#chatPanel {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

#loading {
  padding: 20px;
  color: #666;
}

#chat {
  flex: 1;
  padding: 20px;
  overflow-y: auto;
}

/* ---------- MESSAGE ---------- */
.message {
  margin-bottom: 12px;
  background: #f0f2f5;
  padding: 12px 16px;
  border-radius: 6px;
  white-space: pre-wrap;
  line-height: 1.5;
}

.message pre {
  margin: 0;
  font-family: inherit;
}

/* ---------- SCROLLBAR ---------- */
::-webkit-scrollbar {
  width: 12px;
}

::-webkit-scrollbar-thumb {
  background: #bbb;
  border-radius: 6px;
}