index.html

1. Glassmorphism with backdrop-filter blur
2. Modern gradient background
3. Responsive grid/flex layout
4. Styled for RTL (Persian) text
5. Professional styling for all components
6. Animations for smooth UX
7. Custom scrollbars
8. Mobile responsive breakpoints
9. Hover effects and transitions
10. Proper z-indexing and shadows

The colors are purple/blue gradient based which works well with glassmorphism. All the classes from the HTML are styled. </think> ```css
/* CSS Variables for Glassmorphism Theme */
:root {
  --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --secondary-gradient: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
  --glass-bg: rgba(255, 255, 255, 0.75);
  --glass-bg-dark: rgba(255, 255, 255, 0.4);
  --glass-border: rgba(255, 255, 255, 0.6);
  --glass-shadow: 0 8px 32px 0 rgba(31, 38, 135, 0.2);
  --blur-amount: blur(16px);
  
  --text-primary: #1a202c;
  --text-secondary: #4a5568;
  --accent-color: #667eea;
  --accent-hover: #5568d3;
  --success-color: #48bb78;
  --error-color: #f56565;
  --warning-color: #ed8936;
  
  --border-radius-lg: 24px;
  --border-radius-md: 16px;
  --border-radius-sm: 12px;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Reset & Base */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body.chat-page {
  font-family: 'Segoe UI', system-ui, -apple-system, sans-serif;
  background: var(--primary-gradient);
  background-attachment: fixed;
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 20px;
  color: var(--text-primary);
  line-height: 1.6;
}

/* Glass Container */
.chat-container {
  display: grid;
  grid-template-columns: 320px 1fr;
  width: 100%;
  max-width: 1440px;
  height: 92vh;
  background: var(--glass-bg);
  backdrop-filter: var(--blur-amount);
  -webkit-backdrop-filter: var(--blur-amount);
  border: 1px solid var(--glass-border);
  border-radius: var(--border-radius-lg);
  box-shadow: var(--glass-shadow);
  overflow: hidden;
  position: relative;
}

/* Sidebar - Glass Panel */
.chat-sidebar {
  background: rgba(255, 255, 255, 0.4);
  border-left: 1px solid var(--glass-border);
  display: flex;
  flex-direction: column;
  backdrop-filter: blur(10px);
  position: relative;
}

.sidebar-header {
  padding: 28px 24px;
  background: rgba(255, 255, 255, 0.6);
  border-bottom: 1px solid var(--glass-border);
  backdrop-filter: blur(8px);
}

.sidebar-header h3 {
  font-size: 1.25rem;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 8px;
  font-weight: 700;
}

.sidebar-header h3 i {
  color: var(--accent-color);
  font-size: 1.1rem;
}

.room-name {
  font-size: 0.875rem;
  color: var(--text-secondary);
  font-weight: 500;
  display: block;
  padding-right: 32px;
}

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

.user-item {
  display: flex;
  align-items: center;
  gap: 14px;
  padding: 14px;
  background: rgba(255, 255, 255, 0.6);
  border-radius: var(--border-radius-sm);
  border: 1px solid rgba(255, 255, 255, 0.4);
  transition: var(--transition);
  cursor: pointer;
  position: relative;
  overflow: hidden;
}

.user-item::before {
  content: '';
  position: absolute;
  right: 0;
  top: 0;
  height: 100%;
  width: 4px;
  background: var(--accent-color);
  opacity: 0;
  transition: var(--transition);
}

.user-item:hover {
  background: rgba(255, 255, 255, 0.9);
  transform: translateX(-4px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.08);
}

.user-item:hover::before {
  opacity: 1;
}

.user-avatar {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: var(--primary-gradient);
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  font-size: 1.25rem;
  box-shadow: 0 4px 10px rgba(102, 126, 234, 0.3);
  flex-shrink: 0;
}

.user-info {
  display: flex;
  flex-direction: column;
  flex: 1;
  min-width: 0;
}

.user-name {
  font-weight: 600;
  font-size: 0.95rem;
  color: var(--text-primary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.user-status {
  font-size: 0.8rem;
  display: flex;
  align-items: center;
  gap: 6px;
  margin-top: 2px;
  font-weight: 500;
}

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

.user-status.offline {
  color: var(--text-secondary);
  opacity: 0.7;
}

.user-status i {
  font-size: 0.5rem;
  animation: pulse 2s infinite;
}

.user-status.offline i {
  animation: none;
}

.sidebar-footer {
  padding: 24px;
  border-top: 1px solid var(--glass-border);
  background: rgba(255, 255, 255, 0.5);
  backdrop-filter: blur(8px);
}

/* Main Chat Area */
.chat-main {
  display: flex;
  flex-direction: column;
  background: rgba(255, 255, 255, 0.2);
  position: relative;
}

.chat-header {
  padding: 28px 32px;
  background: rgba(255, 255, 255, 0.65);
  border-bottom: 1px solid var(--glass-border);
  display: flex;
  justify-content: space-between;
  align-items: center;
  backdrop-filter: blur(12px);
  z-index: 10;
}

.header-info h1 {
  font-size: 1.5rem;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 6px;
  font-weight: 700;
}

.header-info h1 i {
  color: var(--accent-color);
  background: rgba(102, 126, 234, 0.1);
  width: 40px;
  height: 40px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 12px;
}

.header-info p {
  color: var(--text-secondary);
  font-size: 0.9rem;
  padding-right: 52px;
}

.header-actions {
  display: flex;
  gap: 12px;
  align-items: center;
}

/* Messages Container */
.chat-messages {
  flex: 1;
  overflow-y: auto;
  padding: 32px;
  display: flex;
  flex-direction: column;
  gap: 20px;
  scroll-behavior: smooth;
  background: rgba(255, 255, 255, 0.3);
}

/* Custom Scrollbar */
.chat-messages::-webkit-scrollbar,
.users-list::-webkit-scrollbar {
  width: 8px;
}

.chat-messages::-webkit-scrollbar-track,
.users-list::-webkit-scrollbar-track {
  background: rgba(255, 255, 255, 0.2);
  border-radius: 10px;
  margin: 4px;
}

.chat-messages::-webkit-scrollbar-thumb,
.users-list::-webkit-scrollbar-thumb {
  background: rgba(102, 126, 234, 0.4);
  border-radius: 10px;
  border: 2px solid transparent;
  background-clip: padding-box;
}

.chat-messages::-webkit-scrollbar-thumb:hover,
.users-list::-webkit-scrollbar-thumb:hover {
  background: rgba(102, 126, 234, 0.7);
  border: 2px solid transparent;
  background-clip: padding-box;
}

/* Message Bubbles - Glass Effect */
.message {
  max-width: 75%;
  padding: 18px 22px;
  border-radius: 20px;
  background: rgba(255, 255, 255, 0.85);
  border: 1px solid rgba(255, 255, 255, 0.8);
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.05);
  position: relative;
  animation: slideIn 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  backdrop-filter: blur(8px);
  transition: var(--transition);
}

.message:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 25px rgba(0, 0, 0, 0.1);
}

.message.own {
  align-self: flex-start;
  background: linear-gradient(135deg, rgba(102, 126, 234, 0.95) 0%, rgba(118, 75, 162, 0.95) 100%);
  color: white;
  border: 1px solid rgba(255, 255, 255, 0.4);
  box-shadow: 0 4px 20px rgba(102, 126, 234, 0.3);
}

.message:not(.own) {
  align-self: flex-end;
  background: rgba(255, 255, 255, 0.95);
}

.message-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 10px;
  font-size: 0.85rem;
  gap: 12px;
}

.message.own .message-header {
  color: rgba(255, 255, 255, 0.95);
}

.message:not(.own) .message-header {
  color: var(--text-secondary);
}

.message-sender {
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 6px;
}

.message-time {
  font-size: 0.75rem;
  opacity: 0.9;
  font-weight: 500;
}

.message-content {
  line-height: 1.6;
  word-wrap: break-word;
  font-size: 0.95rem;
}

.message-actions-admin {
  display: flex;
  gap: 8px;
  opacity: 0;
  transition: var(--transition);
  position: absolute;
  left: -30px;
  top: 50%;
  transform: translateY(-50%);
}

.message:hover .message-actions-admin {
  opacity: 1;
  left: 10px;
}

.message-actions-admin button {
  background: rgba(245, 101, 101, 0.9);
  color: white;
  border: none;
  width: 28px;
  height: 28px;
  border-radius: 8px;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
  transition: var(--transition);
  backdrop-filter: blur(4px);
  box-shadow: 0 2px 8px rgba(245, 101, 101, 0.3);
}

.message-actions-admin button:hover {
  background: var(--error-color);
  transform: scale(1.15) rotate(8deg);
}

/* Chat Footer & Input */
.chat-footer {
  padding: 28px 32px;
  background: rgba(255, 255, 255, 0.7);
  border-top: 1px solid var(--glass-border);
  backdrop-filter: blur(12px);
}

#message-form {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.message-input {
  display: flex;
  gap: 16px;
  align-items: center;
  position: relative;
}

#message-input {
  flex: 1;
  padding: 16px 24px;
  border: 2px solid rgba(102, 126, 234, 0.2);
  border-radius: 28px;
  background: rgba(255, 255, 255, 0.9);
  font-size: 1rem;
  color: var(--text-primary);
  transition: var(--transition);
  outline: none;
  font-family: inherit;
}

#message-input:focus {
  border-color: var(--accent-color);
  background: rgba(255, 255, 255, 1);
  box-shadow: 0 0 0 5px rgba(102, 126, 234, 0.15);
}

#message-input::placeholder {
  color: var(--text-secondary);
  opacity: 0.6;
}

.message-actions {
  display: flex;
  gap: 10px;
  padding: 0 8px;
  align-items: center;
}

/* Buttons */
.btn {
  padding: 12px 24px;
  border: none;
  border-radius: 14px;
  font-weight: 600;
  cursor: pointer;
  display: inline-flex;
  align-items: center;
  gap: 10px;
  transition: var(--transition);
  font-size: 0.95rem;
  backdrop-filter: blur(4px);
  white-space: nowrap;
  position: relative;
  overflow: hidden;
}

.btn::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,0.3), transparent);
  transition: 0.5s;
}

.btn:hover::before {
  left: 100%;
}

.btn-primary {
  background: var(--primary-gradient);
  color: white;
  box-shadow: 0 4px 20px rgba(102, 126, 234, 0.4);
}

.btn-primary:hover {
  transform: translateY(-3px);
  box-shadow: 0 8px 25px rgba(102, 126, 234, 0.5);
}

.btn-secondary {
  background: rgba(255, 255, 255, 0.8);
  color: var(--text-primary);
  border: 1px solid rgba(0, 0, 0, 0.08);
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.05);
}

.btn-secondary:hover {
  background: rgba(255, 255, 255, 1);
  transform: translateY(-2px);
  box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
}

.btn-icon {
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: 1px solid rgba(0, 0, 0, 0.08);
  background: rgba(255, 255, 255, 0.7);
  cursor: pointer;
  font-size: 1.25rem;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: var(--transition);
  backdrop-filter: blur(4px);
}

.btn-icon:hover {
  background: rgba(255, 255, 255, 1);
  transform: scale(1.15) rotate(10deg);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

/* States */
.loading, .empty-state, .error-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 60px 40px;
  text-align: center;
  color: var(--text-secondary);
  gap: 16px;
  background: rgba(255, 255, 255, 0.5);
  border-radius: var(--border-radius-md);
  border: 2px dashed rgba(102, 126, 234, 0.2);
  margin: 20px;
}

.loading {
  border-style: solid;
  background: rgba(255, 255, 255, 0.3);
}

.loading::before {
  content: '';
  width: 48px;
  height: 48px;
  border: 4px solid rgba(102, 126, 234, 0.2);
  border-top-color: var(--accent-color);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

.empty-state i, .error-state i {
  font-size: 3.5rem;
  margin-bottom: 8px;
  opacity: 0.6;
}

.empty-state i {
  color: var(--accent-color);
}

.error-state i {
  color: var(--error-color);
}

.small-text {
  font-size: 0.9rem;
  opacity: 0.8;
  margin-top: 8px;
}

/* Alerts */
.alert {
  padding: 18px 24px;
  border-radius: var(--border-radius-sm);
  display: flex;
  align-items: center;
  gap: 12px;
  font-weight: 600;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
  animation: slideDown 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  backdrop-filter: blur(12px);
  border: 1px solid rgba(255, 255, 255, 0.4);
  z-index: 10000;
}

.alert.success {
  background: rgba(72, 187, 120, 0.95);
  color: white;
}

.alert.error {
  background: rgba(245, 101, 101, 0.95);
  color: white;
}

.alert i {
  font-size: 1.25rem;
}

/* Temp Message */
.temp-message {
  opacity: 0.8;
  border-style: dashed;
}

.sending-status {
  font-size: 0.75rem;
  margin-right: 8px;
  font-style: italic;
  opacity: 0.9;
  display: flex;
  align-items: center;
  gap: 6px;
}

/* Animations */
@keyframes slideIn {
  from {
    opacity: 0;
    transform: translateY(20px) scale(0.95);
  }
  to {
    opacity: 1;
    transform: translateY(0) scale(1);
  }
}

@keyframes spin {
  to {
    transform: rotate(360deg);
  }
}

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

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

/* Responsive Design */
@media (max-width: 1024px) {
  .chat-container {
    grid-template-columns: 280px 1fr;
  }
  
  .chat-header {
    padding: 20px 24px;
  }
  
  .header-info h1 {
    font-size: 1.25rem;
  }
  
  .chat-messages {
    padding: 24px;
  }
}

@media (max-width: 768px) {
  body.chat-page {
    padding: 0;
  }
  
  .chat-container {
    grid-template-columns: 1fr;
    height: 100vh;
    border-radius: 0;
    max-width: 100%;
  }
  
  .chat-sidebar {
    position: fixed;
    right: -100%;
    top: 0;
    width: 300px;
    height: 100vh;
    z-index: 1000;
    transition: right 0.4s cubic-bezier(0.4, 0, 0.2, 1);
    background: rgba(255, 255, 255, 0.98);
    box-shadow: -5px 0 30px rgba(0, 0, 0, 0.1);
  }
  
  .chat-sidebar.active {
    right: 0;
  }
  
  .chat-header {
    padding: 16px 20px;
    flex-direction: column;
    gap: 16px;
    align-items: flex-start;
  }
  
  .header-actions {
    width: 100%;
    justify-content: flex-end;
  }
  
  .message {
    max-width: 90%;
    padding: 14px 18px;
  }
  
  .chat-footer {
    padding: 20px;
  }
  
  .message-input {
    flex-wrap: wrap;
  }
  
  #message-input {
    order: 1;
    flex: 1 0 100%;
    margin-bottom: 12px;
  }
  
  .btn-primary[type="submit"] {
    order: 3;
    flex: 1;
    justify-content: center;
  }
  
  .message-actions {
    order: 2;
    flex: 1;
    justify-content: flex-end;
  }
}

@media (max-width: 480px) {
  .chat-messages {
    padding: 16px;
    gap: 12px;
  }
  
  .message {
    max-width: 95%;
    border-radius: 16px;
    padding: 12px 16px;
  }
  
  .btn {
    padding: 10px 16px;
    font-size: 0.85rem;
  }
  
  .sidebar-header h3 {
    font-size: 1.1rem;
  }
  
  .user-item {
    padding: 10px;
  }
  
  .user-avatar {
    width: 36px;
    height: 36px;
    font-size: 1rem;
  }
}

/* Utility Classes */
.hidden {
  display: none !important;
}

.fade-in {
  animation: slideIn 0.4s ease-out;
}

.glass-panel {
  background: var(--glass-bg);
  backdrop-filter: var(--blur-amount);
  border: 1px solid var(--glass-border);
  border-radius: var(--border-radius-md);
}

.text-gradient {
  background: var(--primary-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}