frontend/src/styles/Sidebar.css

/* Sidebar.css */
.sidebar {
  width: 300px;
  height: 100vh;
  background: var(--sidebar-bg, var(--bg-secondary, #E8E0D4));
  border-right: 1px solid var(--border-primary, var(--border-light, #DDD5C8));
  display: flex;
  flex-direction: column;
  position: fixed;
  left: 0;
  top: 0;
  z-index: 100;
  overflow: hidden;
  transition: width 0.3s ease;
}

/* Collapsed state */
.sidebar.collapsed {
  width: 70px;
}

/* Dark theme support */
.dark .sidebar {
  background: var(--bg-primary-dark, #1f2937);
  border-right-color: var(--border-dark, #374151);
}

/* Toggle Button - Matches User Menu Style */
.sidebar-toggle {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  padding: 0;
  border: none;
  background: none;
  border-radius: 6px;
  cursor: pointer;
  color: var(--text-secondary, #6b7280);
  transition: all 0.2s ease;
}

.sidebar-toggle:hover {
  background: var(--bg-secondary, #f3f4f6);
  color: var(--text-primary, #111827);
}

.dark .sidebar-toggle:hover {
  background: var(--bg-secondary-dark, #374151);
  color: var(--text-primary-dark, #f9fafb);
}

/* Toggle button as collapsed user avatar replacement */
.collapsed-toggle-avatar {
  width: 40px;
  height: 40px;
  background: var(--primary-color, #0B7A8A);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  flex-shrink: 0;
  cursor: pointer;
  transition: all 0.2s ease;
}

.collapsed-toggle-avatar:hover {
  background: var(--primary-color-hover, #096875);
  transform: scale(1.05);
}

/* Header Section */
.sidebar-header {
  padding: 20px;
  border-bottom: 1px solid var(--border-muted, var(--border-light, #e5e7eb));
  flex-shrink: 0;
  transition: all 0.3s ease;
}

.sidebar-brand {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 0;
  min-width: 0;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--border-muted, var(--border-light, #e5e7eb));
}

.sidebar-brand-mark {
  width: 36px;
  height: 36px;
  border-radius: 10px;
  background: transparent;
  color: #fff;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  box-shadow: 0 0 0 1px var(--brand-mark-ring, rgba(18, 20, 23, 0.12)), var(--shadow-sm);
  overflow: hidden;
  padding: 0;
}

.sidebar-brand-mark img {
  width: 100%;
  height: 100%;
  object-fit: contain;
  display: block;
}

.sidebar-brand-text {
  display: flex;
  flex-direction: column;
  gap: 2px;
  min-width: 0;
}

.sidebar-brand-title {
  font-size: 15px;
  font-weight: 700;
  color: var(--text-primary, #1A1714);
  line-height: 1.3;
  letter-spacing: -0.01em;
}

.sidebar-brand-subtitle {
  font-size: 12px;
  color: var(--text-muted, var(--text-tertiary, #6A645C));
  line-height: 1.4;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

[data-theme="dark"] .sidebar-brand,
.dark .sidebar-brand {
  border-bottom-color: var(--border-primary, #374151);
}

.sidebar.collapsed .sidebar-brand {
  justify-content: center;
  margin-bottom: 8px;
  padding-bottom: 0;
  border-bottom: none;
}

.sidebar.collapsed .sidebar-brand-text {
  display: none;
}

.sidebar.collapsed .sidebar-header {
  padding: 20px 10px;
}

.dark .sidebar-header,
[data-theme="dark"] .sidebar-header {
  border-bottom-color: var(--border-primary, #374151);
}

/* Collapsed Header */
.collapsed-header {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
}

.collapsed-user-avatar {
  width: 40px;
  height: 40px;
  background: var(--primary-color, #0B7A8A);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  flex-shrink: 0;
}

.collapsed-new-chat {
  width: 40px;
  height: 40px;
  background: var(--primary-color, #0B7A8A);
  color: white;
  border: none;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all 0.2s ease;
}

.collapsed-new-chat:hover {
  background: var(--primary-color-hover, #096875);
  transform: scale(1.1);
}

.user-section {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: 14px;
  margin-bottom: 16px;
}

.user-info {
  display: flex;
  align-items: center;
  gap: 12px;
  flex: 1;
  min-width: 0;
}

.user-avatar {
  width: 36px;
  height: 36px;
  background: var(--primary-color, #0B7A8A);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  color: white;
  flex-shrink: 0;
}

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

.user-name {
  font-weight: 600;
  color: var(--text-primary, #111827);
  font-size: 14px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.dark .user-name {
  color: var(--text-primary-dark, #f9fafb);
}

.user-email {
  font-size: 12px;
  color: var(--text-secondary, #6b7280);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.dark .user-email {
  color: var(--text-secondary-dark, #9ca3af);
}

.user-stated-goal {
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
  margin-top: 4px;
  font-size: 11.5px;
  line-height: 1.35;
  color: var(--text-secondary, #6b7280);
}

.dark .user-stated-goal {
  color: var(--text-secondary-dark, #9ca3af);
}

.chat-history-label {
  font-size: 11px;
  font-weight: 650;
  letter-spacing: 0.04em;
  text-transform: uppercase;
  color: var(--text-tertiary, var(--text-secondary, #6b7280));
  padding: 4px 2px 8px;
}

/* User Menu */
.user-menu-container {
  position: relative;
}

.user-menu-button {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  padding: 0;
  border: none;
  background: none;
  border-radius: 6px;
  cursor: pointer;
  color: var(--text-secondary, #6b7280);
  transition: all 0.2s ease;
}

.user-menu-button:hover {
  background: var(--bg-secondary, #f3f4f6);
  color: var(--text-primary, #111827);
}

.dark .user-menu-button:hover {
  background: var(--bg-secondary-dark, #374151);
  color: var(--text-primary-dark, #f9fafb);
}

.user-menu {
  position: absolute;
  top: 100%;
  right: 0;
  background: var(--bg-primary, #ffffff);
  border: 1px solid var(--border-light, #e5e7eb);
  border-radius: 8px;
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
  padding: 8px;
  min-width: 180px;
  z-index: 200;
}

.dark .user-menu {
  background: var(--bg-primary-dark, #1f2937);
  border-color: var(--border-dark, #374151);
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.3);
}

.user-menu-item {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 12px;
  width: 100%;
  border: none;
  background: none;
  border-radius: 6px;
  cursor: pointer;
  font-size: 14px;
  color: var(--text-primary, #111827);
  transition: background-color 0.2s ease;
  text-align: left;
}

.user-menu-item > span {
  flex: 1;
}

.dark .user-menu-item {
  color: var(--text-primary-dark, #f9fafb);
}

.user-menu-item:hover {
  background: var(--bg-secondary, #f3f4f6);
}

.dark .user-menu-item:hover {
  background: var(--bg-secondary-dark, #374151);
}

.user-menu-item.sign-out {
  color: #ef4444;
}

.user-menu-item.sign-out:hover {
  background: #fef2f2;
}

.dark .user-menu-item.sign-out:hover {
  background: #7f1d1d;
}

.user-menu-appearance {
  border-top: 1px solid var(--border-light, #e5e7eb);
  margin-top: 4px;
  padding-top: 4px;
}

.dark .user-menu-appearance {
  border-top-color: var(--border-dark, #374151);
}

.appearance-chevron {
  flex-shrink: 0;
  color: var(--text-secondary, #6b7280);
  transition: transform 0.15s ease;
}

.appearance-chevron.open {
  transform: rotate(90deg);
}

.appearance-options {
  padding: 2px 0 4px 8px;
}

.appearance-option.active {
  background: var(--bg-secondary, #f3f4f6);
}

.dark .appearance-option.active {
  background: var(--bg-secondary-dark, #374151);
}

.appearance-check {
  flex-shrink: 0;
  color: var(--accent-primary, #0B7A8A);
}

/* New Chat Button */
.new-chat-button {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  width: 100%;
  padding: 12px 16px;
  background: var(--primary-color, #0B7A8A);
  color: white;
  border: none;
  border-radius: 8px;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s ease;
}

.new-chat-button:hover {
  background: var(--primary-color-hover, #096875);
  transform: translateY(-1px);
}

/* Search Section */
.sidebar-search {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 16px 20px;
  border-bottom: 1px solid var(--border-light, #e5e7eb);
  flex-shrink: 0;
  transition: all 0.3s ease;
}

.sidebar-search .search-container {
  flex: 1;
}

.new-chat-icon-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  flex-shrink: 0;
  border: 1px solid var(--border-primary, #DDD5C8);
  border-radius: 8px;
  background: var(--card-bg, #FFFFFF);
  color: var(--text-secondary, #4A453E);
  cursor: pointer;
  box-shadow: var(--shadow-sm);
  transition: background 0.15s ease, transform 0.15s ease, border-color 0.15s ease;
}

.new-chat-icon-btn:hover {
  background: var(--card-hover, #F7F3EC);
  border-color: var(--border-secondary, #D1C9BB);
  color: var(--text-primary, #1A1714);
  transform: translateY(-1px);
}

.new-chat-icon-btn:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none;
}

.dark .sidebar-search {
  border-bottom-color: var(--border-dark, #374151);
}

.search-container {
  position: relative;
}

.search-icon {
  position: absolute;
  left: 12px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-secondary, #6b7280);
}

.search-input {
  width: 100%;
  padding: 10px 12px 10px 36px;
  border: 1px solid var(--border-light, #e5e7eb);
  border-radius: 8px;
  background: var(--bg-secondary, #f9fafb);
  color: var(--text-primary, #111827);
  font-size: 14px;
  transition: all 0.2s ease;
}

.dark .search-input {
  border-color: var(--border-dark, #374151);
  background: var(--bg-secondary-dark, #374151);
  color: var(--text-primary-dark, #f9fafb);
}

.search-input:focus {
  outline: none;
  border-color: var(--accent-primary, #0B7A8A);
  box-shadow: var(--input-focus-shadow, 0 0 0 3px rgba(11, 122, 138, 0.18));
}

.search-input::placeholder {
  color: var(--text-secondary, #6b7280);
}

.dark .search-input::placeholder {
  color: var(--text-secondary-dark, #9ca3af);
}

/* Chat Sessions */
.chat-sessions {
  flex: 1;
  overflow-y: auto;
  padding: 0 20px 20px;
  transition: padding 0.3s ease;
}

.sidebar.collapsed .chat-sessions {
  padding: 0 10px 20px;
}

.loading-sessions {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 40px 20px;
  color: var(--text-secondary, #6b7280);
  gap: 12px;
}

.sidebar.collapsed .loading-sessions {
  padding: 40px 5px;
}

.dark .loading-sessions {
  color: var(--text-secondary-dark, #9ca3af);
}

.loading-spinner {
  width: 24px;
  height: 24px;
  border: 2px solid var(--border-light, #e5e7eb);
  border-top: 2px solid var(--accent-primary, #0B7A8A);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

.dark .loading-spinner {
  border-color: var(--border-dark, #374151);
  border-top-color: var(--accent-primary, #0B7A8A);
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

.no-sessions {
  text-align: center;
  padding: 40px 20px;
  color: var(--text-secondary, #6b7280);
  font-size: 14px;
}

.sidebar.collapsed .no-sessions {
  padding: 40px 5px;
}

.dark .no-sessions {
  color: var(--text-secondary-dark, #9ca3af);
}

.sessions-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-top: 4px;
}

/* Session Item */
.session-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px;
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.2s ease;
  border: 1px solid transparent;
  group: true;
}

.session-item.collapsed {
  justify-content: center;
  padding: 12px 8px;
}

.session-item:hover {
  background: var(--bg-secondary, #f3f4f6);
  border-color: var(--border-light, #e5e7eb);
}

.dark .session-item:hover {
  background: var(--bg-secondary-dark, #374151);
  border-color: var(--border-dark, #4b5563);
}

.session-item.active {
  background: var(--sidebar-active-bg, #E4EEF0);
  border-color: var(--accent-primary, #0B7A8A);
  color: var(--text-primary, #1A1714);
}

.session-item.active:hover {
  background: var(--sidebar-active-hover, #D7E8EB);
}

.session-item:focus-visible {
  outline: 2px solid var(--accent-primary, #0B7A8A);
  outline-offset: 2px;
}

.dark .session-item.active,
[data-theme="dark"] .session-item.active {
  background: var(--sidebar-active-bg, #1E2C31);
  border-color: var(--accent-primary, #4ECAD6);
  color: var(--text-primary, #F5F2EC);
}

.dark .session-item.active:hover,
[data-theme="dark"] .session-item.active:hover {
  background: var(--sidebar-active-hover, #25383E);
}

.session-content {
  display: flex;
  align-items: center;
  gap: 12px;
  flex: 1;
  min-width: 0;
}

.session-item.collapsed .session-content {
  justify-content: center;
  flex: none;
}

.session-icon {
  color: var(--text-secondary, #6b7280);
  flex-shrink: 0;
}

.dark .session-icon {
  color: var(--text-secondary-dark, #9ca3af);
}

.session-item.active .session-icon {
  color: var(--accent-primary, #0B7A8A);
}

.session-details {
  flex: 1;
  min-width: 0;
}

.session-title {
  font-weight: 500;
  color: var(--text-primary, #111827);
  font-size: 14px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  margin-bottom: 2px;
}

.dark .session-title {
  color: var(--text-primary-dark, #f9fafb);
}

.session-meta {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  color: var(--text-secondary, #6b7280);
}

.dark .session-meta {
  color: var(--text-secondary-dark, #9ca3af);
}

.session-date::after {
  content: "•";
  margin-left: 8px;
}

.new-chat-button:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.collapsed-new-chat:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.loading-sessions {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 16px;
  color: var(--text-secondary);
  font-size: 14px;
}

.loading-spinner {
  width: 16px;
  height: 16px;
  border: 2px solid var(--border-color);
  border-top: 2px solid var(--primary-color);
  border-radius: 50%;
  animation: spin 1s linear infinite;
}

@keyframes spin {
  0% { transform: rotate(0deg); }
  100% { transform: rotate(360deg); }
}

/* Style for creating new chat state */
.new-chat-button span {
  transition: all 0.2s ease;
}

.new-chat-button:disabled span {
  opacity: 0.7;
}

.session-menu-button {
  opacity: 0;
  padding: 6px;
  border: none;
  background: none;
  border-radius: 4px;
  cursor: pointer;
  color: var(--text-secondary, #6b7280);
  transition: all 0.2s ease;
  flex-shrink: 0;
}

.session-item:hover .session-menu-button {
  opacity: 1;
}

.session-menu-button:hover {
  background: var(--bg-tertiary, #f3f4f6);
  color: #ef4444;
}

.dark .session-menu-button:hover {
  background: var(--bg-tertiary-dark, #4b5563);
}

/* Sidebar Footer */
.sidebar-footer {
  flex-shrink: 0;
  padding: 20px;
  border-top: 1px solid var(--border-light, #e5e7eb);
  background: var(--bg-primary, #ffffff);
}

.dark .sidebar-footer {
  border-top-color: var(--border-dark, #374151);
  background: var(--bg-primary-dark, #1f2937);
}

.sidebar-neon-link {
  display: flex;
  align-items: center;
  justify-content: flex-start;
  gap: 8px;
  color: var(--text-primary, #111827);
  text-decoration: none;
  font-size: 28px;
  font-weight: bold;
  transition: opacity 0.2s ease;
}

.sidebar-neon-link:hover {
  opacity: 0.8;
}

.dark .sidebar-neon-link {
  color: var(--text-primary-dark, #f9fafb);
}

.sidebar-neon-logo {
  height: 1em;
  width: auto;
  flex-shrink: 0;
}

.sidebar-copyright-text {
  margin: 8px 0 0 0;
  font-size: 10px;
  line-height: 1.4;
  color: var(--text-secondary, #6b7280);
}

.dark .sidebar-copyright-text {
  color: var(--text-secondary-dark, #9ca3af);
}

.sidebar-patents-link {
  color: var(--text-secondary, #6b7280);
  text-decoration: underline;
}

.dark .sidebar-patents-link {
  color: var(--text-secondary-dark, #9ca3af);
}

.sidebar-footer.collapsed .sidebar-neon-link {
  justify-content: center;
}

.sidebar-footer.collapsed .sidebar-neon-logo {
  height: 28px;
}

/* Tooltip for collapsed state */
.session-item.collapsed {
  position: relative;
}

.mobile-sidebar-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.5);
  z-index: 150;
  display: none;
}

.mobile-sidebar-overlay.visible {
  display: block;
}

.session-item.collapsed:hover::after {
  content: attr(title);
  position: absolute;
  left: 100%;
  top: 50%;
  transform: translateY(-50%);
  background: var(--bg-primary, #ffffff);
  border: 1px solid var(--border-light, #e5e7eb);
  border-radius: 6px;
  padding: 8px 12px;
  margin-left: 8px;
  white-space: nowrap;
  font-size: 12px;
  color: var(--text-primary, #111827);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
  z-index: 1000;
  max-width: 200px;
  overflow: hidden;
  text-overflow: ellipsis;
}

.dark .session-item.collapsed:hover::after {
  background: var(--bg-primary-dark, #1f2937);
  border-color: var(--border-dark, #374151);
  color: var(--text-primary-dark, #f9fafb);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
}

.sidebar-canvas-btn {
  position: relative;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  width: 100%;
  padding: 13px 20px;
  background: var(--accent-gradient);
  border: 1px solid rgba(255, 255, 255, 0.14);
  border-radius: 999px;
  color: var(--accent-on-accent, #ffffff);
  cursor: pointer;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: -0.005em;
  margin-top: 14px;
  margin-bottom: 8px;
  box-shadow: var(--shadow-md), inset 0 1px 0 rgba(255, 255, 255, 0.18);
  transition:
    transform 0.25s cubic-bezier(0.4, 0, 0.2, 1),
    box-shadow 0.3s cubic-bezier(0.4, 0, 0.2, 1),
    background 0.25s ease;
}

/* Sliding shimmer that sweeps across on hover */
.sidebar-canvas-btn::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(
    90deg,
    transparent 0%,
    rgba(255, 255, 255, 0.25) 50%,
    transparent 100%
  );
  transition: left 0.6s ease;
  pointer-events: none;
}

.sidebar-canvas-btn > * {
  position: relative;
  z-index: 1;
}

.sidebar-canvas-btn svg {
  color: #ffffff;
  flex-shrink: 0;
  transition: transform 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

.sidebar-canvas-btn:hover {
  transform: translateY(-2px) scale(1.015);
  filter: brightness(1.06);
  box-shadow: var(--shadow-lg), inset 0 1px 0 rgba(255, 255, 255, 0.28);
}

.sidebar-canvas-btn:hover::before {
  left: 100%;
}

.sidebar-canvas-btn:hover svg {
  transform: rotate(-8deg) scale(1.1);
}

.sidebar-canvas-btn:active {
  transform: translateY(0) scale(1);
  transition-duration: 0.1s;
}

.sidebar.collapsed .sidebar-canvas-btn span {
  display: none;
}

.sidebar.collapsed .sidebar-canvas-btn {
  justify-content: center;
  padding: 12px;
}

/* Responsive Design */
@media (max-width: 768px) {
  .sidebar {
    width: 280px;
    transform: translateX(-100%);
    transition: transform 0.3s ease, width 0.3s ease;
    z-index: 200; /* Higher z-index for mobile */
  }
  
  .sidebar.collapsed {
    width: 70px;
    transform: translateX(-100%); /* Keep hidden when collapsed on mobile */
  }
  
  .sidebar.mobile-open {
    transform: translateX(0);
  }

  .mobile-sidebar-overlay.visible {
    display: block;
  }
}