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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  background: #f0f2f5;
  color: #333;
}

/* Login Page */
.login-container {
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.login-box {
  background: white;
  padding: 40px;
  border-radius: 12px;
  box-shadow: 0 10px 40px rgba(0, 0, 0, 0.1);
  width: 100%;
  max-width: 400px;
}

.logo {
  text-align: center;
  margin-bottom: 30px;
}

.logo h1 {
  font-size: 32px;
  margin-bottom: 8px;
  color: #667eea;
}

.logo p {
  color: #666;
  font-size: 14px;
}

.form-group {
  margin-bottom: 20px;
}

.form-group label {
  display: block;
  margin-bottom: 8px;
  font-weight: 500;
  color: #333;
}

.form-group input {
  width: 100%;
  padding: 12px;
  border: 1px solid #ddd;
  border-radius: 6px;
  font-size: 14px;
  transition: border-color 0.3s;
}

.form-group input:focus {
  outline: none;
  border-color: #667eea;
}

.btn-primary {
  width: 100%;
  padding: 12px;
  background: #667eea;
  color: white;
  border: none;
  border-radius: 6px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.3s;
}

.btn-primary:hover {
  background: #5568d3;
}

.error-message {
  color: #e74c3c;
  font-size: 14px;
  margin-bottom: 15px;
  text-align: center;
}

.info-text {
  text-align: center;
  margin-top: 20px;
  color: #666;
  font-size: 13px;
}

/* Chat Page */
.chat-container {
  display: flex;
  height: 100vh;
  background: #f0f2f5;
}

.sidebar {
  width: 350px;
  background: white;
  border-right: 1px solid #e0e0e0;
  display: flex;
  flex-direction: column;
}

.sidebar-header {
  padding: 20px;
  border-bottom: 1px solid #e0e0e0;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.sidebar-header h2 {
  font-size: 24px;
  color: #333;
}

.user-info {
  padding: 15px 20px;
  border-bottom: 1px solid #e0e0e0;
  display: flex;
  align-items: center;
  gap: 12px;
}

.user-avatar {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: 600;
  font-size: 16px;
}

.user-details {
  flex: 1;
}

.user-name {
  font-weight: 600;
  color: #333;
  font-size: 14px;
}

.user-role {
  font-size: 12px;
  color: #666;
  text-transform: capitalize;
}

.search-box {
  padding: 15px 20px;
  border-bottom: 1px solid #e0e0e0;
  display: flex;
  gap: 10px;
}

.search-box input {
  flex: 1;
  padding: 10px 15px;
  border: 1px solid #ddd;
  border-radius: 20px;
  font-size: 14px;
}

.search-box input:focus {
  outline: none;
  border-color: #667eea;
}

.btn-icon {
  width: 36px;
  height: 36px;
  border: none;
  background: #f0f2f5;
  border-radius: 50%;
  cursor: pointer;
  font-size: 18px;
  transition: background 0.3s;
}

.btn-icon:hover {
  background: #e0e0e0;
}

.filter-tabs {
  display: flex;
  padding: 10px 20px;
  gap: 8px;
  border-bottom: 1px solid #e0e0e0;
  overflow-x: auto;
}

.filter-tab {
  padding: 6px 12px;
  border: 1px solid #ddd;
  background: white;
  border-radius: 16px;
  font-size: 12px;
  cursor: pointer;
  white-space: nowrap;
  transition: all 0.3s;
}

.filter-tab:hover {
  background: #f0f2f5;
}

.filter-tab.active {
  background: #667eea;
  color: white;
  border-color: #667eea;
}

.conversations-list {
  flex: 1;
  overflow-y: auto;
}

.conversation-item {
  padding: 15px 20px;
  border-bottom: 1px solid #f0f2f5;
  cursor: pointer;
  transition: background 0.2s;
  display: flex;
  align-items: center;
  gap: 12px;
}

.conversation-item:hover {
  background: #f8f9fa;
}

.conversation-item.active {
  background: #e8eaf6;
}

.conversation-info {
  flex: 1;
  min-width: 0;
}

.conversation-name {
  font-weight: 600;
  color: #333;
  font-size: 14px;
  margin-bottom: 4px;
}

.conversation-last-message {
  font-size: 13px;
  color: #666;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.conversation-meta {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 4px;
}

.conversation-time {
  font-size: 11px;
  color: #999;
}

.unread-badge {
  background: #667eea;
  color: white;
  border-radius: 10px;
  padding: 2px 8px;
  font-size: 11px;
  font-weight: 600;
}

.main-chat {
  flex: 1;
  display: flex;
  flex-direction: column;
  background: #f0f2f5;
}

.empty-state {
  flex: 1;
  display: flex;
  flex-direction: column;
  justify-content: center;
  align-items: center;
  color: #999;
}

.empty-icon {
  font-size: 64px;
  margin-bottom: 20px;
}

.empty-state h3 {
  font-size: 24px;
  margin-bottom: 8px;
  color: #666;
}

.empty-state p {
  font-size: 14px;
}

.chat-area {
  flex: 1;
  display: flex;
  flex-direction: column;
}

.chat-header {
  background: white;
  padding: 15px 20px;
  border-bottom: 1px solid #e0e0e0;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.chat-user-info {
  display: flex;
  align-items: center;
  gap: 12px;
}

.chat-user-name {
  font-weight: 600;
  color: #333;
  font-size: 16px;
}

.chat-user-status {
  font-size: 12px;
  color: #999;
}

.chat-user-status.online {
  color: #4caf50;
}

.messages-container {
  flex: 1;
  overflow-y: auto;
  padding: 20px;
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.message {
  display: flex;
  gap: 8px;
  max-width: 70%;
  animation: fadeIn 0.3s;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.message.mine {
  align-self: flex-end;
  flex-direction: row-reverse;
}

.message-avatar {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-weight: 600;
  font-size: 12px;
  flex-shrink: 0;
}

.message-content {
  flex: 1;
}

.message-bubble {
  background: white;
  padding: 10px 14px;
  border-radius: 18px;
  word-wrap: break-word;
  box-shadow: 0 1px 2px rgba(0, 0, 0, 0.1);
}

.message.mine .message-bubble {
  background: #667eea;
  color: white;
}

.message-time {
  font-size: 11px;
  color: #999;
  margin-top: 4px;
  padding: 0 8px;
}

.typing-indicator {
  padding: 10px 20px;
  display: flex;
  align-items: center;
  gap: 8px;
  color: #666;
  font-size: 13px;
}

.typing-dots {
  display: flex;
  gap: 4px;
}

.typing-dots span {
  width: 6px;
  height: 6px;
  background: #999;
  border-radius: 50%;
  animation: typing 1.4s infinite;
}

.typing-dots span:nth-child(2) {
  animation-delay: 0.2s;
}

.typing-dots span:nth-child(3) {
  animation-delay: 0.4s;
}

@keyframes typing {
  0%, 60%, 100% { transform: translateY(0); }
  30% { transform: translateY(-10px); }
}

.message-input-container {
  background: white;
  padding: 15px 20px;
  border-top: 1px solid #e0e0e0;
  display: flex;
  gap: 12px;
  align-items: flex-end;
}

#messageInput {
  flex: 1;
  padding: 10px 15px;
  border: 1px solid #ddd;
  border-radius: 20px;
  font-size: 14px;
  font-family: inherit;
  resize: none;
  max-height: 120px;
}

#messageInput:focus {
  outline: none;
  border-color: #667eea;
}

.btn-send {
  padding: 10px 24px;
  background: #667eea;
  color: white;
  border: none;
  border-radius: 20px;
  font-size: 14px;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.3s;
}

.btn-send:hover {
  background: #5568d3;
}

.btn-send:disabled {
  background: #ccc;
  cursor: not-allowed;
}

/* Modal */
.modal {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: rgba(0, 0, 0, 0.5);
  display: flex;
  justify-content: center;
  align-items: center;
  z-index: 1000;
}

.modal-content {
  background: white;
  border-radius: 12px;
  width: 90%;
  max-width: 500px;
  max-height: 80vh;
  display: flex;
  flex-direction: column;
}

.modal-header {
  padding: 20px;
  border-bottom: 1px solid #e0e0e0;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.modal-header h3 {
  font-size: 20px;
  color: #333;
}

.modal-close {
  width: 32px;
  height: 32px;
  border: none;
  background: #f0f2f5;
  border-radius: 50%;
  font-size: 24px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  color: #666;
}

.modal-close:hover {
  background: #e0e0e0;
}

.modal-body {
  padding: 20px;
  overflow-y: auto;
}

.modal-body input {
  width: 100%;
  padding: 10px 15px;
  border: 1px solid #ddd;
  border-radius: 6px;
  font-size: 14px;
  margin-bottom: 15px;
}

.modal-body input:focus {
  outline: none;
  border-color: #667eea;
}

.users-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.user-item {
  padding: 12px;
  border: 1px solid #e0e0e0;
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.2s;
  display: flex;
  align-items: center;
  gap: 12px;
}

.user-item:hover {
  background: #f8f9fa;
  border-color: #667eea;
}

.user-item-info {
  flex: 1;
}

.user-item-name {
  font-weight: 600;
  color: #333;
  font-size: 14px;
  margin-bottom: 2px;
}

.user-item-role {
  font-size: 12px;
  color: #666;
  text-transform: capitalize;
}

.user-item-org {
  font-size: 11px;
  color: #999;
}

.loading {
  text-align: center;
  padding: 20px;
  color: #999;
}

/* Responsive */
@media (max-width: 768px) {
  .sidebar {
    width: 100%;
    position: absolute;
    z-index: 10;
  }
  
  .sidebar.hidden {
    display: none;
  }
  
  .filter-tabs {
    overflow-x: auto;
  }
}