* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  font-size: 16px;
  background: #f5f5f5;
  height: 100vh;
}

.chat-container {
  max-width: 800px;
  margin: 30px auto;
  background: #fff;
  border-radius: 8px;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  height: 80vh;
  position: relative;
}

header {
  background: #4462ff;
  color: #fff;
  padding: 15px;
  text-align: center;
}

.user-info {
  background-color: #e7eaff;
  padding: 8px 15px;
  font-size: 14px;
  color: #555;
  font-weight: 500;
  text-align: right;
}

.channel-control {
  padding: 15px;
  background-color: #f0f2ff;
  border-bottom: 1px solid #e2e6ff;
}

#channel-form {
  display: flex;
  margin-bottom: 10px;
}

#channel-input {
  flex: 1;
  padding: 8px;
  border: 1px solid #ddd;
  border-radius: 4px;
  font-size: 14px;
  outline: none;
}

#channel-indicator {
  font-size: 14px;
  color: #555;
  background-color: #e4e8ff;
  padding: 8px;
  border-radius: 4px;
  text-align: center;
}

#channel-indicator.direct-message {
  background-color: #ffe4f5;
  color: #d4006e;
}

.user-list {
  position: absolute;
  top: 160px;
  right: -200px;
  width: 180px;
  background-color: #fff;
  border-radius: 8px;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
  z-index: 10;
  transition: right 0.3s ease;
}

.chat-container:hover .user-list {
  right: -190px;
}

.user-list:hover {
  right: 10px !important;
}

.user-list-header {
  background-color: #4462ff;
  color: #fff;
  padding: 10px;
  text-align: center;
  font-weight: 500;
  border-radius: 8px 8px 0 0;
}

.user-item {
  padding: 10px;
  border-bottom: 1px solid #eee;
  cursor: pointer;
  transition: background-color 0.2s;
}

.user-item:hover {
  background-color: #f5f5ff;
}

.user-item.selected {
  background-color: #e0e4ff;
  font-weight: 500;
}

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

#chat-messages {
  height: 100%;
}

.message {
  padding: 10px;
  margin-bottom: 10px;
  border-radius: 5px;
  background-color: #f1f1f1;
  max-width: 80%;
  position: relative;
  left: 0;
}

.message.own-message {
  background-color: #e3f2fd;
  left: 20%;
}

.message .meta {
  font-size: 0.8rem;
  color: #777;
  margin-bottom: 5px;
}

.system-message {
  text-align: center;
  background-color: #e6f7ff;
  color: #0070cc;
  padding: 5px;
  margin: 10px auto;
  border-radius: 5px;
  font-size: 0.9rem;
  max-width: 90%;
}

.notification {
  position: fixed;
  top: 20px;
  right: 20px;
  background-color: #4462ff;
  color: white;
  padding: 10px 15px;
  border-radius: 5px;
  box-shadow: 0 3px 10px rgba(0, 0, 0, 0.2);
  cursor: pointer;
  z-index: 100;
  animation: fade-in 0.3s;
}

@keyframes fade-in {
  from { opacity: 0; transform: translateY(-20px); }
  to { opacity: 1; transform: translateY(0); }
}

.chat-form-container {
  padding: 15px;
  background-color: #f9f9f9;
  border-top: 1px solid #eee;
}

#chat-form {
  display: flex;
}

#chat-form input {
  flex: 1;
  padding: 10px;
  border: 1px solid #ddd;
  border-radius: 4px;
  font-size: 16px;
  outline: none;
}

.btn {
  padding: 10px 15px;
  background: #4462ff;
  color: #fff;
  border: none;
  border-radius: 4px;
  margin-left: 10px;
  cursor: pointer;
}

.btn:hover {
  background: #3651d8;
}