* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
  }
  
  body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: #1a1a1a;
    min-height: 100dvh;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: 20px;
    color: #e0e0e0;
    overflow: hidden;
  }
  
  @media (max-width: 768px) {
    body {
      padding: 0;
      align-items: stretch;
    }
  }
  
  /* Selection Screen Styles */
  #selectionScreen {
    background: #252525;
    border-radius: 16px;
    padding: 32px;
    max-width: 500px;
    width: 100%;
    height: 100dvh;
    max-height: 90vh;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
    animation: fadeIn 0.3s ease-in;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    border: 1px solid #333;
    min-height: 0;
    position: relative;
  }

  .selection-header{
    display: inline-block;
  }
  
  #selectionScreenContent {
    flex: 1;
    overflow-y: auto;
  }
  
  #selectionScreenContent::-webkit-scrollbar {
    width: 6px;
  }
  
  #selectionScreenContent::-webkit-scrollbar-track {
    background: #1f1f1f;
    border-radius: 3px;
  }
  
  #selectionScreenContent::-webkit-scrollbar-thumb {
    background: #444;
    border-radius: 3px;
  }
  
  #selectionScreenContent::-webkit-scrollbar-thumb:hover {
    background: #555;
  }
  
  @keyframes fadeIn {
    from {
      opacity: 0;
      transform: translateY(-10px);
    }
    to {
      opacity: 1;
      transform: translateY(0);
    }
  }
  
  #selectionScreen h1 {
    color: #e0e0e0;
    margin-bottom: 24px;
    text-align: center;
    font-size: 1.75rem;
    font-weight: 600;
    flex-shrink: 0;
    letter-spacing: -0.5px;
    padding-top: 0;
    margin-top: 0;
  }
  
  .selection-group {
    margin-bottom: 24px;
  }
  
  .selection-group label {
    display: block;
    margin-bottom: 12px;
    color: #b0b0b0;
    font-weight: 500;
    font-size: 0.875rem;
    letter-spacing: 0.3px;
  }
  
  #usernameInput {
    width: 100%;
    padding: 12px 16px;
    border: 1px solid #3a3a3a;
    border-radius: 8px;
    font-size: 0.95rem;
    transition: all 0.2s ease;
    background: #1f1f1f;
    color: #e0e0e0;
  }
  
  #usernameInput:focus {
    outline: none;
    border-color: #a8c8ec;
    background: #252525;
  }
  
  .color-options {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
  }
  
  .color-option {
    width: 44px;
    height: 44px;
    border-radius: 50%;
    border: 2px solid transparent;
    cursor: pointer;
    transition: all 0.2s ease;
    position: relative;
  }
  
  .color-option:hover {
    transform: scale(1.08);
    border-color: #555;
  }
  
  .color-option.selected {
    border-color: #a8c8ec;
    box-shadow: 0 0 0 2px #1a1a1a, 0 0 0 4px #a8c8ec;
  }
  
  .color-option.selected::after {
    content: '✓';
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    color: white;
    font-weight: 600;
    font-size: 1rem;
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.5);
  }
  
  .icon-options {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    gap: 10px;
  }
  
  .icon-option {
    width: 56px;
    height: 56px;
    border: 1.5px solid #3a3a3a;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.2s ease;
    font-size: 1.6rem;
    background: #1f1f1f;
  }
  
  .icon-option:hover {
    border-color: #a8c8ec;
    background: #2a2a2a;
  }
  
  .icon-option.selected {
    border-color: #a8c8ec;
    background: #2d3542;
    box-shadow: 0 0 0 2px #1a1a1a, 0 0 0 4px #a8c8ec;
  }
  
  .continue-btn {
    width: 100%;
    padding: 14px;
    background: #a8c8ec;
    color: #1a1a1a;
    border: none;
    border-radius: 8px;
    font-size: 0.95rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
    margin-top: 20px;
    flex-shrink: 0;
    position: sticky;
    bottom: 0;
  }
  
  .continue-btn:hover {
    background: #9bb8e0;
  }
  
  .continue-btn:active {
    transform: scale(0.98);
  }
  
  /* Chat Room Styles */
  #chatRoom {
    display: none;
    width: 100%;
    max-width: 1200px;
    height: 90vh;
    background: #252525;
    border-radius: 16px;
    box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
    overflow: hidden;
    flex-direction: column;
    border: 1px solid #333;
  }
  
  #chatRoom.active {
    display: flex;
  }
  
  @media (max-width: 768px) {
    #chatRoom {
      height: 100dvh;
      max-height: 100dvh;
      border-radius: 0;
      border: none;
      box-shadow: none;
    }
  }
  
  .chat-header {
    background: #1f1f1f;
    color: #e0e0e0;
    padding: 18px 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid #333;
    flex-shrink: 0;
  }
  
  @media (max-width: 768px) {
    .chat-header {
      padding: 12px 16px;
      padding-top: calc(12px + env(safe-area-inset-top));
    }
  }
  
  .header-right {
    display: flex;
    align-items: center;
    gap: 12px;
  }
  
  .connection-status {
    font-size: 0.75rem;
    padding: 4px 8px;
    border-radius: 4px;
    background: #444;
    color: #b0b0b0;
  }
  
  .connection-status.connected {
    background: #2d4a2d;
    color: #8bc88b;
  }
  
  .connection-status.error {
    background: #4a2d2d;
    color: #c88b8b;
  }
  
  .chat-header h1 {
    font-size: 1.25rem;
    font-weight: 600;
    letter-spacing: -0.3px;
  }
  
  .user-info {
    display: flex;
    align-items: center;
    gap: 10px;
  }
  
  .user-avatar {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.65rem;
    border: 1.5px solid #3a3a3a;
  }
  
  .chat-container {
    display: flex;
    flex: 1;
    overflow: hidden;
  }
  
  .users-sidebar {
    width: 240px;
    background: #1f1f1f;
    border-right: 1px solid #333;
    padding: 16px;
    overflow-y: auto;
    flex-shrink: 0;
  }
  
  @media (max-width: 768px) {
    .users-sidebar {
      width: 100%;
      border-right: none;
      border-bottom: 1px solid #333;
      padding: 12px 16px;
      position: relative;
      transition: max-height 0.3s ease;
    }
    
    .users-sidebar.mobile-collapsed {
      max-height: 50px;
      overflow: hidden;
    }
    
    .users-sidebar.mobile-expanded {
      max-height: 300px;
      overflow-y: auto;
      position: fixed;
      top: 0;
      left: 0;
      right: 0;
      z-index: 200;
      background: #1f1f1f;
      box-shadow: 0 4px 12px rgba(0, 0, 0, 0.5);
    }
    
    .users-sidebar.mobile-expanded #users {
      display: block !important;
      max-height: 250px;
      overflow-y: auto;
    }
    
    .users-header {
      cursor: pointer;
      padding: 4px 0;
      display: flex;
      align-items: center;
      justify-content: space-between;
    }
    
    .users-header::after {
      content: '▼';
      font-size: 0.7rem;
      transition: transform 0.3s ease;
      color: #888;
    }
    
    .users-sidebar.mobile-expanded .users-header::after {
      transform: rotate(180deg);
    }
    
    .users-sidebar.mobile-collapsed .users-header::after {
      transform: rotate(0deg);
    }
  }
  
  .users-sidebar::-webkit-scrollbar {
    width: 6px;
  }
  
  .users-sidebar::-webkit-scrollbar-track {
    background: #1a1a1a;
  }
  
  .users-sidebar::-webkit-scrollbar-thumb {
    background: #444;
    border-radius: 3px;
  }
  
  .users-sidebar::-webkit-scrollbar-thumb:hover {
    background: #555;
  }
  
  .users-sidebar h3 {
    color: #b0b0b0;
    margin-bottom: 12px;
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.5px;
    text-transform: uppercase;
  }
  
  .users-header {
    user-select: none;
  }
  
  .user-item {
    padding: 10px 12px;
    margin-bottom: 6px;
    background: #2a2a2a;
    border-radius: 8px;
    display: flex;
    align-items: center;
    gap: 10px;
    transition: all 0.15s ease;
    border: 1px solid transparent;
  }
  
  .user-item:hover {
    background: #303030;
  }
  
  .user-item.current-user {
    background: #2d3542;
    border-color: #a8c8ec;
  }
  
  .user-item.current-user:hover {
    background: #333a48;
  }
  
  .user-item-avatar {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    flex-shrink: 0;
    border: 1px solid rgba(255, 255, 255, 0.1);
  }
  
  .user-item-name {
    font-size: 0.875rem;
    color: #e0e0e0;
    font-weight: 400;
  }
  
  .user-item.current-user .user-item-name {
    font-weight: 500;
    color: #e8e8e8;
  }

  .avatar-emoji {
    line-height: 1;
    display: inline-block;
    transform: translateX(3px);
  }
  
  .chat-main {
    flex: 1;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    position: relative;
  }
  
  @media (max-width: 768px) {
    .chat-main {
      padding-bottom: 0;
    }
  }
  
  #chat {
    flex: 1;
    overflow-y: auto;
    padding: 20px;
    background: #1a1a1a;
    scroll-behavior: smooth;
  }
  
  @media (max-width: 768px) {
    #chat {
      padding: 16px;
      -webkit-overflow-scrolling: touch;
    }
  }
  
  #chat::-webkit-scrollbar {
    width: 8px;
  }
  
  #chat::-webkit-scrollbar-track {
    background: #1f1f1f;
  }
  
  #chat::-webkit-scrollbar-thumb {
    background: #444;
    border-radius: 4px;
  }
  
  #chat::-webkit-scrollbar-thumb:hover {
    background: #555;
  }
  
  .system {
    color: #888;
    font-size: 0.7rem;
    font-style: italic;
    background-color: transparent;
    width: fit-content;
    margin: 8px auto;
    padding: 4px 12px;
    border-radius: 6px;
    display: block;
    opacity: 0.6;
    text-align: center;
  }
  
  .message {
    margin-bottom: 2px;
    padding: 10px 14px;
    border-radius: 12px;
    max-width: 70%;
    display: flex;
    flex-direction: column;
    gap: 4px;
    word-wrap: break-word;
    animation: messageSlideIn 0.2s ease-out;
  }
  
  .message.consecutive {
    margin-top: 2px;
  }
  
  .message.consecutive.other {
    border-top-left-radius: 4px;
  }
  
  .message.consecutive.self {
    border-top-right-radius: 4px;
  }
  
  @keyframes messageSlideIn {
    from {
      opacity: 0;
      transform: translateY(4px);
    }
    to {
      opacity: 1;
      transform: translateY(0);
    }
  }
  
  .message .author {
    font-weight: 500;
    font-size: 0.75rem;
    opacity: 0.85;
    display: flex;
    align-items: center;
    gap: 6px;
    margin-bottom: 2px;
  }
  
  .message .author-icon {
    font-size: 0.85rem;
  }
  
  .message .content {
    font-size: 0.9rem;
    line-height: 1.5;
  }
  
  .self {
    background: #a8c8ec;
    color: #1a1a1a;
    margin-left: auto;
    border-bottom-right-radius: 4px;
  }
  
  .self .author {
    color: rgba(26, 26, 26, 0.8);
  }
  
  .other {
    background: #2a2a2a;
    color: #e0e0e0;
    margin-right: auto;
    border-bottom-left-radius: 4px;
    border: 1px solid #333;
  }
  
  .other .author {
    color: #b0b0b0;
  }
  
  .chat-input-container {
    padding: 16px 20px;
    background: #1f1f1f;
    border-top: 1px solid #333;
    flex-shrink: 0;
  }
  
  @media (max-width: 768px) {
    #chatRoom {
      padding-bottom: 0;
    }
    
    .chat-input-container {
      padding: 12px 16px;
      padding-bottom: calc(12px + env(safe-area-inset-bottom));
    }
  }
  
  #chatForm {
    display: flex;
    gap: 10px;
  }
  
  #messageInput {
    flex: 1;
    padding: 12px 16px;
    border: 1px solid #3a3a3a;
    border-radius: 8px;
    font-size: 0.9rem;
    transition: all 0.2s ease;
    background: #252525;
    color: #e0e0e0;
  }
  
  #messageInput:focus {
    outline: none;
    border-color: #a8c8ec;
    background: #2a2a2a;
  }
  
  .send-btn {
    padding: 12px 20px;
    background: #a8c8ec;
    color: #1a1a1a;
    border: none;
    border-radius: 8px;
    font-size: 0.9rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s ease;
  }
  
  .send-btn:hover {
    background: #9bb8e0;
  }
  
  .send-btn:active {
    transform: scale(0.98);
  }
  
  /* Responsive Design */
  @media (max-width: 768px) {
    #selectionScreen {
      padding: 16px;
      padding-bottom: 0;
      height: 100dvh;
      max-height: 100vh;
      border-radius: 0;
      border: none;
      box-shadow: none;
      padding-top: calc(16px + env(safe-area-inset-top));
      min-height: 0;
      display: flex;
      flex-direction: column;
      position: relative;
    }
    
    #selectionScreen h1 {
      font-size: 1.5rem;
      margin-bottom: 16px;
      padding-top: 0;
      margin-top: 0;
      flex-shrink: 0;
    }
    
    #selectionScreenContent {
      min-height: 0;
      flex: 1;
      overflow-y: auto;
      -webkit-overflow-scrolling: touch;
      margin-bottom: 0;
      padding-right: 8px;
    }
    
    .selection-group {
      margin-bottom: 20px;
    }
    
    .selection-group:last-child {
      margin-bottom: 0;
      padding-bottom: 40px;
    }
    
    .icon-options {
      margin-bottom: 15px;
      padding-bottom: 15px;
    }
    
    .continue-btn {
      margin-top: 0;
      padding: 16px;
      padding-bottom: .4rem;
      font-size: 0.9rem;
      flex-shrink: 0;
      z-index: 100;
      width: 100%;
      border-radius: 0;
      -webkit-tap-highlight-color: transparent;
      background: #1b2127;
      color: #e0e0e0;
      border-top: 1px solid rgba(0, 0, 0, 0.1);
      box-shadow: 0 -2px 10px rgba(0, 0, 0, 0.3);
      height: auto;
      min-height: 52px;
    }
    
    #selectionScreen {
      display: flex;
      flex-direction: column;
    }
  
    .icon-options {
      grid-template-columns: repeat(4, 1fr);
    }
  
    .chat-container {
      flex-direction: column;
      flex: 1;
      overflow: hidden;
    }
  
    .message {
      max-width: 85%;
    }
  
    .chat-header h1 {
      font-size: 1.1rem;
    }
  
    .header-right {
      gap: 8px;
    }
  
    .connection-status {
      font-size: 0.7rem;
      padding: 3px 6px;
    }
  
    .user-avatar {
      width: 32px;
      height: 32px;
      font-size: 1rem;
    }
  
    .user-info {
      gap: 8px;
    }
  
    .user-info .user-name {
      font-size: 0.85rem;
    }
  
    #messageInput {
      font-size: 16px;
      padding: 10px 14px;
    }
  
    .send-btn {
      padding: 10px 16px;
      font-size: 0.85rem;
    }
  }