:root,
[data-theme="light"] {
  --color-app-bg: #F7F4EF;
  --color-sidebar-bg: #F0EBE3;
  --color-message-user: #E8E2D9;
  --color-active-item: #E0DAD0;
  --color-secondary-text: #6B6560;
  --color-border-color: #D4CCC0;
  --color-primary-text: #1C1C1C;
  --color-overlay: rgba(28, 28, 28, 0.35);
  --color-overlay-heavy: rgba(28, 28, 28, 0.82);
  --color-overlay-medium: rgba(28, 28, 28, 0.5);
  --color-dropdown-bg: #F7F4EF;
  --color-code-inline-bg: #E8E2D9;
  --color-code-text: #7A5C2E;
  --color-pre-bg: #F0EBE3;
  --color-link: #3D5A80;
  --color-accent: #2C2C2C;
  --color-accent-text: #F7F4EF;
  --color-accent-disabled-bg: #E0DAD0;
  --color-accent-disabled-text: #9A948C;
  --color-btn-bg: #1C1C1C;
  --color-btn-text: #F7F4EF;
  --color-btn-hover: #333333;
  --color-em-text: #5C574F;
  --color-sheet-bg: #F0EBE3;
  --color-sheet-handle: #C4BCB0;
  --color-sheet-close-bg: #E8E2D9;
  --color-toggle-bg: rgba(240, 235, 227, 0.92);
  --color-toggle-border: #D4CCC0;
  --color-toggle-hover: #E8E2D9;
  --color-shadow: rgba(28, 28, 28, 0.12);
  --color-delete-hover: #E8E2D9;
}

[data-theme="dark"] {
  --color-app-bg: #1A1A1A;
  --color-sidebar-bg: #212121;
  --color-message-user: #2A2A2A;
  --color-active-item: #303030;
  --color-secondary-text: #888888;
  --color-border-color: #2E2E2E;
  --color-primary-text: #F2F2F2;
  --color-overlay: rgba(0, 0, 0, 0.5);
  --color-overlay-heavy: rgba(0, 0, 0, 0.9);
  --color-overlay-medium: rgba(0, 0, 0, 0.6);
  --color-dropdown-bg: #2A2A2A;
  --color-code-inline-bg: #2A2A2A;
  --color-code-text: #E8B86D;
  --color-pre-bg: #212121;
  --color-link: #6B9FD4;
  --color-accent: #0A84FF;
  --color-accent-text: #FFFFFF;
  --color-accent-disabled-bg: #2A2A2A;
  --color-accent-disabled-text: #888888;
  --color-btn-bg: #FFFFFF;
  --color-btn-text: #000000;
  --color-btn-hover: #E5E5E5;
  --color-em-text: #AAAAAA;
  --color-sheet-bg: #1C1C1C;
  --color-sheet-handle: #3A3A3C;
  --color-sheet-close-bg: #2A2A2A;
  --color-toggle-bg: rgba(33, 33, 33, 0.92);
  --color-toggle-border: #2E2E2E;
  --color-toggle-hover: #303030;
  --color-shadow: rgba(0, 0, 0, 0.4);
  --color-delete-hover: #303030;
}

.theme-toggle {
  position: fixed;
  top: 0.75rem;
  right: 0.75rem;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
  width: 2.25rem;
  height: 2.25rem;
  border-radius: 9999px;
  border: 1px solid var(--color-toggle-border);
  background: var(--color-toggle-bg);
  color: var(--color-primary-text);
  cursor: pointer;
  backdrop-filter: blur(8px);
  box-shadow: 0 1px 4px var(--color-shadow);
  transition: background 0.15s, border-color 0.15s, color 0.15s;
}

.theme-toggle:hover {
  background: var(--color-toggle-hover);
}

.theme-toggle-icon.hidden {
  display: none;
}

.btn-primary {
  background: var(--color-btn-bg);
  color: var(--color-btn-text);
  transition: background 0.15s;
}

.btn-primary:hover:not(:disabled) {
  background: var(--color-btn-hover);
}

.bg-overlay-medium {
  background: var(--color-overlay-medium);
}

.bg-overlay-heavy {
  background: var(--color-overlay-heavy);
}

.typing-dots span {
  animation: blink 1.4s infinite;
  animation-fill-mode: both;
}

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

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

@keyframes blink {
  0%, 80%, 100% { opacity: 0; }
  40% { opacity: 1; }
}

#messages-container {
  overflow-y: auto;
  scroll-behavior: smooth;
  line-height: 1.65;
}

#message-input {
  resize: none;
}

#lightbox {
  position: fixed;
  inset: 0;
  background: var(--color-overlay-heavy);
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: center;
}

#lightbox.hidden {
  display: none;
}

.chat-item {
  cursor: pointer;
  padding: 0.625rem 0.75rem;
  border-radius: 0.75rem;
  font-size: 0.875rem;
  color: var(--color-primary-text);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.chat-item-title {
  flex: 1;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.chat-menu {
  position: relative;
  flex-shrink: 0;
}

.chat-menu-btn {
  opacity: 0;
  background: none;
  border: none;
  cursor: pointer;
  font-size: 1.125rem;
  line-height: 1;
  padding: 0.125rem 0.375rem;
  color: var(--color-secondary-text);
  transition: opacity 0.15s, color 0.15s;
}

.chat-item:hover .chat-menu-btn,
.chat-item.active .chat-menu-btn {
  opacity: 1;
}

.chat-menu-btn:hover {
  color: var(--color-primary-text);
}

.chat-menu-dropdown {
  position: absolute;
  right: 0;
  top: 100%;
  margin-top: 0.25rem;
  min-width: 8rem;
  background: var(--color-dropdown-bg);
  border: 1px solid var(--color-border-color);
  border-radius: 0.5rem;
  box-shadow: 0 4px 12px var(--color-shadow);
  z-index: 50;
  overflow: hidden;
}

.chat-menu-delete {
  display: block;
  width: 100%;
  text-align: left;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem 0.75rem;
  font-size: 0.875rem;
  color: #f87171;
  transition: background 0.15s;
}

.chat-menu-delete:hover {
  background: var(--color-delete-hover);
}

.chat-item:hover {
  background: var(--color-delete-hover);
}

.chat-item.active {
  background: var(--color-delete-hover);
}

.chat-item-pending .chat-item-title {
  color: var(--color-secondary-text);
}

.chat-item-pending-marker {
  flex-shrink: 0;
  color: var(--color-secondary-text);
  font-size: 0.875rem;
  line-height: 1;
}

.image-message-bubble img {
  max-width: 100%;
  border-radius: 0.75rem;
  margin-top: 0.5rem;
}

@media (min-width: 768px) {
  .sidebar-panel {
    position: relative;
    left: 0;
  }

  .sidebar-overlay {
    display: none !important;
  }
}

@media (max-width: 767px) {
  html {
    scroll-behavior: auto;
  }

  #messages-container {
    scroll-behavior: auto;
  }

  .sidebar-panel {
    position: fixed;
    z-index: 50;
    top: 0;
    left: -260px;
    width: 260px;
    height: 100vh;
    transition: left 0.3s ease;
  }

  .sidebar-panel.open {
    left: 0;
  }

  .sidebar-overlay {
    position: fixed;
    inset: 0;
    background: var(--color-overlay);
    z-index: 40;
  }

  .sidebar-overlay.hidden {
    display: none;
  }

  .mobile-input-container {
    background: var(--color-sidebar-bg);
    border-radius: 20px;
    padding: 12px 16px;
  }

  #message-input-mobile {
    width: 100%;
    background: transparent;
    border: none;
    min-height: 24px;
    max-height: 144px;
    resize: none;
    outline: none;
    font-size: 1rem;
    line-height: 1.5;
  }

  .mobile-input-toolbar {
    display: flex;
    align-items: center;
    gap: 8px;
    margin-top: 8px;
  }

  .mobile-icon-btn {
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: var(--color-message-user);
    color: var(--color-primary-text);
    border: none;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.125rem;
    flex-shrink: 0;
  }

  .mobile-model-pill {
    background: var(--color-message-user);
    color: var(--color-primary-text);
    font-size: 13px;
    border-radius: 999px;
    padding: 6px 12px;
    border: none;
    white-space: nowrap;
    max-width: 160px;
    overflow: hidden;
    text-overflow: ellipsis;
  }

  .mobile-toolbar-spacer {
    flex: 1;
  }

  .mobile-send-btn {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--color-accent);
    color: var(--color-accent-text);
    border: none;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    font-weight: 600;
    flex-shrink: 0;
  }

  .mobile-send-btn:disabled {
    background: var(--color-message-user);
    color: var(--color-secondary-text);
  }

  .model-sheet-item {
    display: flex;
    align-items: center;
    padding: 1rem 0;
    border-bottom: 1px solid var(--color-border-color);
    cursor: pointer;
  }

  .model-sheet-item:last-child {
    border-bottom: none;
  }

  .model-sheet-check {
    margin-left: auto;
    color: var(--color-accent);
  }
}

.ai-message h1,
.ai-message h2,
.ai-message h3 {
  font-weight: 600;
  margin: 16px 0 8px 0;
  color: var(--color-primary-text);
}

.ai-message h1 {
  font-size: 1.2em;
}

.ai-message h2 {
  font-size: 1.1em;
}

.ai-message h3 {
  font-size: 1em;
}

.ai-message p {
  margin: 0 0 10px 0;
}

.ai-message ul,
.ai-message ol {
  padding-left: 20px;
  margin: 8px 0;
}

.ai-message ul {
  list-style-type: disc;
}

.ai-message ol {
  list-style-type: decimal;
}

.ai-message li {
  margin: 4px 0;
}

.ai-message strong {
  color: var(--color-primary-text);
  font-weight: 600;
}

.ai-message em {
  color: var(--color-em-text);
}

.ai-message code {
  background: var(--color-code-inline-bg);
  padding: 2px 6px;
  border-radius: 4px;
  font-family: 'JetBrains Mono', 'Fira Code', monospace;
  font-size: 0.85em;
  color: var(--color-code-text);
}

.ai-message pre {
  background: var(--color-pre-bg);
  border: 1px solid var(--color-border-color);
  padding: 16px;
  border-radius: 8px;
  overflow-x: auto;
  margin: 12px 0;
}

.ai-message pre code {
  background: none;
  padding: 0;
  color: var(--color-code-text);
}

.ai-message blockquote {
  border-left: 3px solid var(--color-secondary-text);
  padding-left: 12px;
  margin: 8px 0;
  color: var(--color-secondary-text);
}

.ai-message hr {
  border: none;
  border-top: 1px solid var(--color-border-color);
  margin: 16px 0;
}

.ai-message a {
  color: var(--color-link);
  text-decoration: underline;
}

.desktop-attach-btn,
.mobile-icon-btn.is-loading {
  width: 2.5rem;
  height: 2.5rem;
}

.desktop-attach-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 9999px;
  border: 1px solid var(--color-border-color);
  background: var(--color-sidebar-bg);
  color: var(--color-primary-text);
  font-size: 1.25rem;
  line-height: 1;
  cursor: pointer;
  transition: background 0.15s, opacity 0.15s;
}

.desktop-attach-btn:hover:not(:disabled) {
  background: var(--color-delete-hover);
}

.desktop-attach-btn:disabled {
  opacity: 0.6;
  cursor: not-allowed;
}

.attachment-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.message-attachments {
  display: flex;
  flex-wrap: wrap;
  gap: 0.5rem;
}

.attachment-chip {
  display: flex;
  align-items: center;
  gap: 0.625rem;
  background: var(--color-code-inline-bg);
  border-radius: 8px;
  padding: 0.5rem 0.625rem;
  max-width: 240px;
}

.attachment-chip-thumb {
  width: 40px;
  height: 40px;
  border-radius: 4px;
  object-fit: cover;
  flex-shrink: 0;
}

.attachment-chip-icon {
  width: 40px;
  height: 40px;
  border-radius: 4px;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-sidebar-bg);
  flex-shrink: 0;
  font-size: 1.25rem;
}

.attachment-chip-info {
  min-width: 0;
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 0.125rem;
}

.attachment-chip-name {
  font-size: 0.8125rem;
  color: var(--color-primary-text);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.attachment-chip-size {
  font-size: 0.75rem;
  color: var(--color-secondary-text);
}

.attachment-chip-remove {
  background: none;
  border: none;
  color: var(--color-secondary-text);
  cursor: pointer;
  font-size: 1.125rem;
  line-height: 1;
  padding: 0 0.125rem;
  flex-shrink: 0;
}

.attachment-chip-uploading {
  opacity: 0.75;
}

.attachment-chip-spinner {
  animation: attachment-chip-pulse 1s ease-in-out infinite;
}

@keyframes attachment-chip-pulse {
  0%, 100% { opacity: 0.4; }
  50% { opacity: 1; }
}

.attachment-chip-remove:hover {
  color: var(--color-primary-text);
}

.video-frame-upload {
  aspect-ratio: 16 / 9;
  max-width: 100%;
  border: 2px dashed var(--color-border-color);
  border-radius: 0.75rem;
  background: var(--color-sidebar-bg);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  overflow: hidden;
  transition: border-color 0.15s, background 0.15s;
}

.video-frame-upload:hover {
  border-color: var(--color-secondary-text);
  background: var(--color-active-item);
}

.video-frame-placeholder {
  color: var(--color-secondary-text);
  font-size: 0.875rem;
}

.video-frame-preview {
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.video-progress-track {
  width: 100%;
  height: 0.5rem;
  background: var(--color-active-item);
  border-radius: 9999px;
  overflow: hidden;
}

.video-progress-bar {
  height: 100%;
  width: 0%;
  background: var(--color-accent);
  border-radius: 9999px;
  transition: width 0.4s ease;
}

.duration-btn {
  border: 1px solid var(--color-border-color);
  border-radius: 9999px;
  padding: 0.375rem 0.875rem;
  font-size: 0.875rem;
  color: var(--color-secondary-text);
  background: var(--color-sidebar-bg);
  cursor: pointer;
  transition: background 0.15s, color 0.15s, border-color 0.15s;
}

.duration-btn:hover {
  background: var(--color-active-item);
  color: var(--color-primary-text);
}

.duration-btn.active {
  background: var(--color-btn-bg);
  color: var(--color-btn-text);
  border-color: var(--color-btn-bg);
}

.video-history-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(160px, 1fr));
  gap: 1rem;
}

.video-history-card {
  border: 1px solid var(--color-border-color);
  border-radius: 0.75rem;
  overflow: hidden;
  background: var(--color-sidebar-bg);
}

.video-history-card-preview {
  aspect-ratio: 16 / 9;
  width: 100%;
  object-fit: cover;
  background: var(--color-active-item);
}

.video-history-card-body {
  padding: 0.625rem 0.75rem;
  display: flex;
  flex-direction: column;
  gap: 0.375rem;
}

.video-history-card-status {
  font-size: 0.75rem;
  color: var(--color-secondary-text);
}

.video-history-card-status.failed {
  color: #f87171;
}

.video-history-card-download {
  font-size: 0.75rem;
  color: var(--color-primary-text);
  text-decoration: underline;
}

.video-history-card-download:hover {
  color: var(--color-link);
}

.sidebar-hidden {
  display: none !important;
}

.mode-tabs-nav {
  justify-content: flex-start;
  gap: 0.75rem;
  overflow-x: auto;
  overflow-y: hidden;
  flex-wrap: nowrap;
  scrollbar-width: none;
  -ms-overflow-style: none;
  -webkit-overflow-scrolling: touch;
}

.mode-tabs-nav::-webkit-scrollbar {
  display: none;
}

.mode-tab {
  flex-shrink: 0;
  white-space: nowrap;
}

@media (min-width: 768px) {
  .mode-tabs-nav {
    justify-content: center;
    gap: 1.25rem;
    overflow-x: visible;
  }
}

.tag-pill {
  border: 1px solid var(--color-border-color);
  border-radius: 9999px;
  padding: 0.375rem 0.875rem;
  font-size: 0.875rem;
  color: var(--color-secondary-text);
  background: var(--color-sidebar-bg);
  cursor: pointer;
  pointer-events: auto;
  user-select: none;
  -webkit-tap-highlight-color: transparent;
  transition: background 0.15s, color 0.15s, border-color 0.15s;
}

.tag-pill:hover {
  background: var(--color-active-item);
  color: var(--color-primary-text);
}

.tag-pill.active {
  background: var(--color-btn-bg);
  color: var(--color-btn-text);
  border-color: var(--color-btn-bg);
}

.voice-speed-slider {
  accent-color: var(--color-accent);
}

.mode-panel {
  position: relative;
  z-index: 2;
  flex: 1 1 0;
  min-height: 0;
}

#messages-container.hidden {
  display: none !important;
  flex: 0 0 0 !important;
  min-height: 0 !important;
  overflow: hidden !important;
}

.music-history-card-preview {
  aspect-ratio: 16 / 9;
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--color-active-item);
}

.music-history-icon {
  font-size: 2rem;
  color: var(--color-secondary-text);
}

.voice-card {
  border: 1px solid var(--color-border-color);
  border-radius: 0.75rem;
  padding: 0.875rem 1rem;
  text-align: left;
  background: var(--color-sidebar-bg);
  cursor: pointer;
  transition: background 0.15s, border-color 0.15s, color 0.15s;
}

.voice-card:hover {
  background: var(--color-active-item);
}

.voice-card.active {
  background: var(--color-btn-bg);
  border-color: var(--color-btn-bg);
  color: var(--color-btn-text);
}

.voice-card-title {
  display: block;
  font-size: 0.9375rem;
  font-weight: 600;
}

.voice-card-subtitle {
  display: block;
  font-size: 0.75rem;
  opacity: 0.85;
  margin-top: 0.125rem;
}

.voice-history-item {
  border: 1px solid var(--color-border-color);
  border-radius: 0.75rem;
  padding: 0.875rem 1rem;
  background: var(--color-sidebar-bg);
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.voice-history-player {
  width: 100%;
  height: 2.25rem;
}

.voice-history-download {
  font-size: 0.75rem;
  color: var(--color-primary-text);
  text-decoration: underline;
}

.voice-history-download:hover {
  color: var(--color-link);
}

@media (max-width: 768px) { .download-btn { opacity: 1 !important; } }