:root {
  --primary-color: #007AFF;
  --primary-hover: #0051D5;
  --secondary-color: #5856D6;
  --success-color: #34C759;
  --danger-color: #FF3B30;
  --warning-color: #FF9500;
  
  --bg-primary: #FFFFFF;
  --bg-secondary: #F5F5F7;
  --bg-tertiary: #E8E8ED;
  
  --text-primary: #000000;
  --text-secondary: #6E6E73;
  --text-tertiary: #A1A1A6;
  
  --border-color: #D1D1D6;
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.12);
  
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 20px;
  
  --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html, body {
  height: 100%;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'Segoe UI', 'Helvetica Neue', Arial, sans-serif;
  background: var(--bg-secondary);
  color: var(--text-primary);
  overflow: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  min-height: 100dvh;
  height: 100dvh;
}

/* ============ 认证页面 ============ */

.auth-page {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  padding: 20px;
  animation: gradientShift 15s ease infinite;
  background-size: 200% 200%;
}

@keyframes gradientShift {
  0% { background-position: 0% 50%; }
  50% { background-position: 100% 50%; }
  100% { background-position: 0% 50%; }
}

.auth-container {
  width: 100%;
  max-width: 420px;
}

.auth-card {
  background: rgba(255, 255, 255, 0.95);
  backdrop-filter: blur(20px) saturate(180%);
  border-radius: var(--radius-xl);
  padding: 48px 40px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
  animation: slideUp 0.6s cubic-bezier(0.4, 0, 0.2, 1);
}

@keyframes slideUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.auth-logo {
  display: flex;
  justify-content: center;
  margin-bottom: 32px;
  animation: scaleIn 0.8s cubic-bezier(0.34, 1.56, 0.64, 1) 0.2s both;
}

@keyframes scaleIn {
  from {
    opacity: 0;
    transform: scale(0.8);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

.auth-title {
  font-size: 32px;
  font-weight: 700;
  text-align: center;
  margin-bottom: 8px;
  color: var(--text-primary);
  letter-spacing: -0.5px;
}

.auth-subtitle {
  font-size: 15px;
  color: var(--text-secondary);
  text-align: center;
  margin-bottom: 32px;
}

.auth-form {
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.form-group label {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.form-group input,
.form-group textarea {
  padding: 14px 16px;
  border: 2px solid var(--border-color);
  border-radius: var(--radius-md);
  font-size: 16px;
  transition: var(--transition);
  background: var(--bg-primary);
  font-family: inherit;
}

.form-group input:focus,
.form-group textarea:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 4px rgba(0, 122, 255, 0.1);
}

.form-group textarea {
  resize: vertical;
  min-height: 80px;
}

.form-footer {
  display: flex;
  justify-content: flex-end;
  margin-top: -12px;
}

.forgot-link {
  font-size: 14px;
  color: var(--primary-color);
  text-decoration: none;
  font-weight: 500;
  transition: var(--transition);
}

.forgot-link:hover {
  color: var(--primary-hover);
}

.btn-primary {
  padding: 14px 24px;
  background: var(--primary-color);
  color: white;
  border: none;
  border-radius: var(--radius-md);
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  box-shadow: 0 4px 12px rgba(0, 122, 255, 0.3);
}

.btn-primary:hover {
  background: var(--primary-hover);
  transform: translateY(-2px);
  box-shadow: 0 6px 16px rgba(0, 122, 255, 0.4);
}

.btn-primary:active {
  transform: translateY(0);
}

.btn-secondary {
  padding: 12px 20px;
  background: var(--bg-secondary);
  color: var(--text-primary);
  border: 2px solid var(--border-color);
  border-radius: var(--radius-md);
  font-size: 15px;
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
}

.btn-secondary:hover {
  background: var(--bg-tertiary);
  border-color: var(--text-tertiary);
}

.auth-switch {
  text-align: center;
  margin-top: 24px;
  font-size: 15px;
  color: var(--text-secondary);
}

.auth-switch a {
  color: var(--primary-color);
  text-decoration: none;
  font-weight: 600;
  transition: var(--transition);
}

.auth-switch a:hover {
  color: var(--primary-hover);
}

/* ============ 主应用页面 ============ */

.app-page {
  display: flex;
  height: 100dvh;
  min-height: 100dvh;
  background: var(--bg-secondary);
}

/* 侧边栏 */
.sidebar {
  width: 320px;
  background: var(--bg-primary);
  border-right: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  animation: slideInLeft 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

@keyframes slideInLeft {
  from {
    opacity: 0;
    transform: translateX(-20px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

.sidebar-header {
  padding: 20px;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: linear-gradient(135deg, rgba(0, 122, 255, 0.05) 0%, rgba(88, 86, 214, 0.05) 100%);
}

.user-info {
  display: flex;
  align-items: center;
  gap: 12px;
  flex: 1;
}

.user-avatar {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  object-fit: cover;
  border: 2px solid var(--primary-color);
}

.user-details {
  flex: 1;
}

.username {
  font-size: 16px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 2px;
}

.user-status {
  font-size: 13px;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  gap: 6px;
}

.user-status.online::before {
  content: '';
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--success-color);
  animation: pulse 2s infinite;
}

@keyframes pulse {
  0%, 100% {
    opacity: 1;
  }
  50% {
    opacity: 0.5;
  }
}

.icon-btn {
  width: 36px;
  height: 36px;
  border: none;
  background: transparent;
  border-radius: var(--radius-sm);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-secondary);
  transition: var(--transition);
}

.icon-btn:hover {
  background: var(--bg-secondary);
  color: var(--text-primary);
}

.sidebar-actions {
  padding: 16px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  border-bottom: 1px solid var(--border-color);
}

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

.groups-list-header {
  padding: 16px 20px 12px;
  font-size: 13px;
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.group-item {
  padding: 12px 20px;
  cursor: pointer;
  transition: var(--transition);
  border-left: 3px solid transparent;
  position: relative;
}

.group-item:hover {
  background: var(--bg-secondary);
}

.group-item.active {
  background: linear-gradient(90deg, rgba(0, 122, 255, 0.1) 0%, rgba(0, 122, 255, 0.05) 100%);
  border-left-color: var(--primary-color);
}

.group-item-name {
  font-size: 15px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 4px;
}

.group-item-info {
  font-size: 13px;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  gap: 8px;
}

.unread-badge {
  background: var(--danger-color);
  color: white;
  font-size: 11px;
  font-weight: 700;
  padding: 2px 8px;
  border-radius: 12px;
  margin-left: auto;
}

/* 主内容区 */
.main-content {
  flex: 1;
  display: flex;
  flex-direction: column;
  position: relative;
  background: var(--bg-secondary);
  min-height: 0;
}

.welcome-screen {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  animation: fadeIn 0.6s ease;
}

@keyframes fadeIn {
  from {
    opacity: 0;
  }
  to {
    opacity: 1;
  }
}

.welcome-content {
  text-align: center;
  padding: 40px;
}

.welcome-content svg {
  margin-bottom: 24px;
  animation: float 3s ease-in-out infinite;
}

@keyframes float {
  0%, 100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-10px);
  }
}

.welcome-content h2 {
  font-size: 28px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 12px;
  letter-spacing: -0.5px;
}

.welcome-content p {
  font-size: 16px;
  color: var(--text-secondary);
}

/* 聊天区域 */
.chat-area {
  flex: 1;
  display: flex;
  flex-direction: column;
  background: var(--bg-primary);
  animation: fadeIn 0.4s ease;
  min-height: 0;
}

.chat-header {
  padding: 16px 24px;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: var(--bg-primary);
  backdrop-filter: blur(20px) saturate(180%);
}

.chat-header-info {
  flex: 1;
}

.group-name {
  font-size: 20px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 2px;
  letter-spacing: -0.3px;
}

.group-members-count {
  font-size: 13px;
  color: var(--text-secondary);
}

.chat-header-actions {
  display: flex;
  gap: 8px;
}

/* 公告栏 */
.announcement-banner {
  padding: 12px 24px;
  background: linear-gradient(135deg, rgba(255, 149, 0, 0.1) 0%, rgba(255, 204, 0, 0.1) 100%);
  border-bottom: 1px solid rgba(255, 149, 0, 0.2);
  display: flex;
  align-items: center;
  gap: 12px;
  animation: slideDown 0.4s ease;
}

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

.announcement-icon {
  font-size: 20px;
}

.announcement-text {
  flex: 1;
  font-size: 14px;
  color: var(--text-primary);
  line-height: 1.5;
}

/* 置顶消息栏 */
.pinned-messages-banner {
  padding: 12px 24px;
  background: linear-gradient(135deg, rgba(0, 122, 255, 0.1) 0%, rgba(88, 86, 214, 0.1) 100%);
  border-bottom: 1px solid rgba(0, 122, 255, 0.2);
  display: flex;
  align-items: center;
  gap: 12px;
  animation: slideDown 0.4s ease;
  cursor: pointer;
  transition: var(--transition);
}

.pinned-messages-banner:hover {
  background: linear-gradient(135deg, rgba(0, 122, 255, 0.15) 0%, rgba(88, 86, 214, 0.15) 100%);
}

.pinned-icon {
  font-size: 20px;
}

.pinned-messages-content {
  flex: 1;
  font-size: 14px;
  color: var(--text-primary);
  line-height: 1.5;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

/* 消息容器 */
.messages-container {
  flex: 1;
  overflow-y: auto;
  padding: 24px;
  scroll-behavior: smooth;
  min-height: 0;
}

.messages-container::-webkit-scrollbar {
  width: 8px;
}

.messages-container::-webkit-scrollbar-track {
  background: transparent;
}

.messages-container::-webkit-scrollbar-thumb {
  background: var(--border-color);
  border-radius: 4px;
}

.messages-container::-webkit-scrollbar-thumb:hover {
  background: var(--text-tertiary);
}

/* 消息 */
.message {
  display: flex;
  gap: 12px;
  margin-bottom: 20px;
  animation: messageSlideIn 0.3s ease;
  position: relative;
}

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

.message-avatar {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  object-fit: cover;
  flex-shrink: 0;
}

.message-content {
  flex: 1;
  max-width: 600px;
}

.message-header {
  display: flex;
  align-items: baseline;
  gap: 8px;
  margin-bottom: 6px;
}

.message-username {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-primary);
}

.message-time {
  font-size: 12px;
  color: var(--text-tertiary);
}

.message-edited {
  font-size: 11px;
  color: var(--text-tertiary);
  font-style: italic;
}

.message-reply-to {
  padding: 8px 12px;
  background: var(--bg-secondary);
  border-left: 3px solid var(--primary-color);
  border-radius: var(--radius-sm);
  margin-bottom: 8px;
  font-size: 13px;
  color: var(--text-secondary);
  cursor: pointer;
  transition: var(--transition);
}

.message-reply-to:hover {
  background: var(--bg-tertiary);
}

.message-reply-to strong {
  color: var(--primary-color);
}

.message-text {
  padding: 12px 16px;
  background: var(--bg-secondary);
  border-radius: var(--radius-md);
  font-size: 15px;
  line-height: 1.6;
  color: var(--text-primary);
  word-wrap: break-word;
  position: relative;
}

.message.pinned .message-text::before {
  content: '📌';
  position: absolute;
  top: -8px;
  right: -8px;
  font-size: 16px;
}

.message-image {
  max-width: 100%;
  max-height: 400px;
  border-radius: var(--radius-md);
  margin-top: 8px;
  cursor: pointer;
  transition: var(--transition);
}

.message-image:hover {
  transform: scale(1.02);
  box-shadow: var(--shadow-lg);
}

.message-video {
  max-width: 100%;
  max-height: 400px;
  border-radius: var(--radius-md);
  margin-top: 8px;
  background: #000;
}

.message-actions {
  display: flex;
  gap: 4px;
  margin-top: 8px;
  opacity: 0;
  transition: var(--transition);
}

.message:hover .message-actions {
  opacity: 1;
}

.message.show-actions .message-actions {
  opacity: 1;
}

.message-action-btn {
  padding: 4px 12px;
  background: transparent;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  font-size: 12px;
  color: var(--text-secondary);
  cursor: pointer;
  transition: var(--transition);
}

.message-action-btn:hover {
  background: var(--bg-secondary);
  color: var(--text-primary);
  border-color: var(--text-tertiary);
}

/* 正在输入指示器 */
.typing-indicator {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 12px 16px;
  color: var(--text-secondary);
  font-size: 14px;
  animation: fadeIn 0.3s ease;
}

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

.typing-dots span {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--text-tertiary);
  animation: typingBounce 1.4s infinite ease-in-out;
}

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

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

@keyframes typingBounce {
  0%, 60%, 100% {
    transform: translateY(0);
  }
  30% {
    transform: translateY(-8px);
  }
}

/* 引用预览 */
.reply-preview {
  padding: 12px 24px;
  background: linear-gradient(135deg, rgba(0, 122, 255, 0.05) 0%, rgba(88, 86, 214, 0.05) 100%);
  border-top: 1px solid var(--border-color);
  animation: slideUp 0.3s ease;
}

.reply-preview-content {
  display: flex;
  align-items: center;
  gap: 12px;
  max-width: 600px;
}

.reply-preview-text {
  flex: 1;
  font-size: 13px;
  color: var(--text-secondary);
}

.reply-preview-text strong {
  color: var(--primary-color);
}

.reply-preview-text p {
  margin-top: 4px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.cancel-reply {
  width: 28px;
  height: 28px;
  border: none;
  background: var(--bg-tertiary);
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  color: var(--text-secondary);
  transition: var(--transition);
  flex-shrink: 0;
}

.cancel-reply:hover {
  background: var(--danger-color);
  color: white;
}

/* 消息输入区 */
.message-input-container {
  border-top: 1px solid var(--border-color);
  background: var(--bg-primary);
  padding: 16px 24px;
}

.message-input-wrapper {
  display: flex;
  align-items: flex-end;
  gap: 8px;
  background: var(--bg-secondary);
  border-radius: var(--radius-lg);
  padding: 8px 12px;
  transition: var(--transition);
  position: relative;
}

.message-input-wrapper:focus-within {
  background: var(--bg-primary);
  box-shadow: 0 0 0 3px rgba(0, 122, 255, 0.1);
}

.message-input {
  flex: 1;
  border: none;
  background: transparent;
  font-size: 15px;
  font-family: inherit;
  resize: none;
  max-height: 120px;
  padding: 8px;
  color: var(--text-primary);
}

.message-input:focus {
  outline: none;
}

.send-btn {
  width: 40px;
  height: 40px;
  border: none;
  background: var(--primary-color);
  color: white;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition);
  flex-shrink: 0;
}

.send-btn:hover {
  background: var(--primary-hover);
  transform: scale(1.05);
}

.send-btn:active {
  transform: scale(0.95);
}

/* Emoji 选择器 */
.emoji-picker {
  background: var(--bg-primary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 12px;
  margin-top: 12px;
  box-shadow: var(--shadow-md);
  animation: slideUp 0.3s ease;
  position: absolute;
  bottom: 56px;
  left: 12px;
  z-index: 300;
}

.emoji-grid {
  display: grid;
  grid-template-columns: repeat(10, 1fr);
  gap: 8px;
  font-size: 24px;
  max-height: 200px;
  overflow-y: auto;
}

.emoji-grid span {
  cursor: pointer;
  transition: var(--transition);
  text-align: center;
  padding: 4px;
  border-radius: var(--radius-sm);
}

.emoji-grid span:hover {
  background: var(--bg-secondary);
  transform: scale(1.2);
}

/* 附件预览 */
.attachment-preview {
  padding: 12px 24px 0;
  background: var(--bg-primary);
}

.attachment-preview-content {
  display: flex;
  align-items: center;
  gap: 12px;
  background: var(--bg-secondary);
  border-radius: var(--radius-lg);
  padding: 10px 12px;
}

.attachment-media img,
.attachment-media video {
  width: 72px;
  height: 72px;
  object-fit: cover;
  border-radius: var(--radius-md);
}

.attachment-meta {
  flex: 1;
}

.attachment-name {
  font-size: 14px;
  color: var(--text-primary);
}

.attachment-hint {
  font-size: 12px;
  color: var(--text-secondary);
  margin-top: 4px;
}

/* 图片预览弹窗 */
.image-modal {
  position: fixed;
  inset: 0;
  z-index: 300;
  display: flex;
  align-items: center;
  justify-content: center;
}

.image-modal-backdrop {
  position: absolute;
  inset: 0;
  background: rgba(0, 0, 0, 0.65);
}

.image-modal-content {
  position: relative;
  max-width: 90vw;
  max-height: 90vh;
  z-index: 1;
}

.image-modal-content img {
  max-width: 90vw;
  max-height: 90vh;
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
}

.mobile-only {
  display: none;
}

/* 侧边栏遮罩 */
.sidebar-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.35);
  z-index: 90;
}

.panel-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.35);
  z-index: 95;
}

/* 右侧面板 */
.right-panel {
  width: 340px;
  background: var(--bg-primary);
  border-left: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  animation: slideInRight 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

@keyframes slideInRight {
  from {
    opacity: 0;
    transform: translateX(20px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

.panel-header {
  padding: 20px;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  background: linear-gradient(135deg, rgba(0, 122, 255, 0.05) 0%, rgba(88, 86, 214, 0.05) 100%);
}

.panel-header h3 {
  font-size: 18px;
  font-weight: 700;
  color: var(--text-primary);
}

.panel-content {
  flex: 1;
  overflow-y: auto;
  padding: 20px;
}

.panel-section {
  margin-bottom: 32px;
}

.panel-section-title {
  font-size: 13px;
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.5px;
  margin-bottom: 16px;
}

.group-detail-item {
  padding: 12px 0;
  border-bottom: 1px solid var(--border-color);
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  gap: 12px;
}

.group-detail-item:last-child {
  border-bottom: none;
}

.detail-label {
  font-size: 14px;
  font-weight: 500;
  color: var(--text-secondary);
}

.detail-value {
  font-size: 14px;
  color: var(--text-primary);
  font-weight: 500;
  text-align: right;
}

.detail-description {
  font-size: 14px;
  color: var(--text-secondary);
  line-height: 1.6;
  margin-top: 8px;
}

.panel-btn {
  width: 100%;
  padding: 12px 16px;
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  font-size: 14px;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition);
  margin-bottom: 8px;
  display: flex;
  align-items: center;
  gap: 8px;
  color: var(--text-primary);
}

.panel-btn:hover {
  background: var(--bg-tertiary);
  border-color: var(--text-tertiary);
}

/* 成员列表 */
.members-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.member-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px;
  border-radius: var(--radius-md);
  transition: var(--transition);
}

.member-item:hover {
  background: var(--bg-secondary);
}

.member-avatar {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  object-fit: cover;
  position: relative;
}

.member-info {
  flex: 1;
}

.member-name {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 2px;
}

.member-role {
  font-size: 12px;
  color: var(--text-secondary);
}

.member-status {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--text-tertiary);
  flex-shrink: 0;
}

.member-status.online {
  background: var(--success-color);
}

.member-action-btn {
  border: 1px solid var(--border-color);
  background: var(--bg-tertiary);
  color: var(--text-primary);
  padding: 6px 10px;
  border-radius: 999px;
  font-size: 12px;
  cursor: pointer;
  transition: var(--transition);
  flex-shrink: 0;
}

.member-action-btn:hover {
  background: var(--bg-secondary);
  border-color: var(--text-tertiary);
}

/* 模态框 */
.modal-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(4px);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  animation: fadeIn 0.2s ease;
}

.modal {
  background: var(--bg-primary);
  border-radius: var(--radius-xl);
  padding: 32px;
  width: 90%;
  max-width: 480px;
  box-shadow: var(--shadow-lg);
  animation: scaleIn 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.modal h3 {
  font-size: 24px;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 24px;
}

.modal-actions {
  display: flex;
  gap: 12px;
  margin-top: 24px;
}

.modal-actions button {
  flex: 1;
}

/* 群组预览 */
.group-preview {
  padding: 16px;
  background: var(--bg-secondary);
  border-radius: var(--radius-md);
  margin: 16px 0;
}

.group-preview-info strong {
  display: block;
  font-size: 16px;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.group-preview-info p {
  font-size: 14px;
  color: var(--text-secondary);
  margin-bottom: 8px;
  line-height: 1.5;
}

.group-preview-info small {
  font-size: 13px;
  color: var(--text-tertiary);
}

/* 响应式设计 */
@media (max-width: 1024px) {
  .right-panel {
    position: fixed;
    top: 0;
    right: 0;
    bottom: 0;
    z-index: 100;
    box-shadow: var(--shadow-lg);
  }
}

@media (max-width: 768px) {
  .mobile-only {
    display: inline-flex;
  }

  .app-page {
    padding-bottom: 72px;
  }

  .chat-header {
    padding: 12px 16px;
  }

  .message-input-container {
    padding: 12px 16px;
  }

  .sidebar {
    position: fixed;
    left: -320px;
    top: 0;
    bottom: 0;
    z-index: 100;
    transition: var(--transition);
  }

  .sidebar.open {
    left: 0;
    box-shadow: var(--shadow-lg);
  }

  .auth-card {
    padding: 32px 24px;
  }

  .modal {
    width: 95%;
    padding: 24px;
  }

  .right-panel {
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    top: auto;
    height: 70vh;
    width: auto;
    z-index: 110;
    border-radius: 16px 16px 0 0;
    box-shadow: var(--shadow-lg);
  }
}

/* 移动端底部操作栏 */
.mobile-tabbar {
  position: fixed;
  left: 0;
  right: 0;
  bottom: 0;
  height: 64px;
  background: var(--bg-primary);
  border-top: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-around;
  z-index: 120;
  box-shadow: 0 -6px 16px rgba(0, 0, 0, 0.08);
}

.tab-btn {
  border: none;
  background: transparent;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  color: var(--text-secondary);
  font-size: 11px;
  cursor: pointer;
  min-width: 60px;
}

.tab-btn:active {
  transform: scale(0.98);
}

.tab-icon {
  font-size: 18px;
}

@media (min-width: 769px) {
  .mobile-tabbar {
    display: none !important;
  }
}

/* 工具类 */
.hidden {
  display: none !important;
}

.text-center {
  text-align: center;
}

.mt-1 {
  margin-top: 8px;
}

.mt-2 {
  margin-top: 16px;
}

.mb-1 {
  margin-bottom: 8px;
}

.mb-2 {
  margin-bottom: 16px;
}