:root {
  --bg-primary: #0f0f0f;
  --bg-secondary: #1a1a1a;
  --bg-tertiary: #252525;
  --bg-hover: #2d2d2d;
  --bg-active: #343434;
  --border: #333;
  --text-primary: #ececec;
  --text-secondary: #a0a0a0;
  --text-muted: #666;
  --accent: #10a37f;
  --accent-hover: #0d8c6d;
  --accent-dim: rgba(16, 163, 127, 0.15);
  --user-bg: #2a2a2a;
  --ai-bg: transparent;
  --danger: #e74c3c;
  --warning: #f39c12;
  --sidebar-width: 280px;
  --topbar-height: 56px;
  --input-area-min: 120px;
  --radius: 12px;
  --radius-sm: 8px;
  --shadow: 0 2px 12px rgba(0, 0, 0, 0.4);
  --font: 'Vazirmatn', system-ui, sans-serif;
  --user-msg-bg: #1a1a1a;
  --mono: 'Cascadia Code', 'Fira Code', Consolas, monospace;
  --transition: 0.2s ease;
}

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

html, body {
  height: 100%;
  overflow: hidden;
}

body {
  font-family: var(--font);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
}

.app {
  display: flex;
  height: 100vh;
  overflow: hidden;
}

/* Sidebar */
.sidebar {
  width: var(--sidebar-width);
  min-width: var(--sidebar-width);
  background: var(--bg-secondary);
  border-left: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  transition: margin var(--transition), min-width var(--transition), width var(--transition), opacity var(--transition);
  overflow: hidden;
}

.sidebar.collapsed {
  width: 0;
  min-width: 0;
  margin-right: calc(-1 * var(--sidebar-width));
  opacity: 0;
  pointer-events: none;
}

.sidebar-header {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 12px;
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
}

.sidebar-title {
  font-size: 14px;
  font-weight: 600;
  color: var(--text-secondary);
}

.chat-list {
  flex: 1;
  overflow-y: auto;
  padding: 8px;
}

.chat-item {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: background var(--transition);
  margin-bottom: 2px;
  position: relative;
}

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

.chat-item.active {
  background: var(--bg-active);
}

.chat-item-title {
  flex: 1;
  font-size: 13px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  color: var(--text-primary);
}

.chat-item-delete {
  opacity: 0;
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  padding: 4px;
  border-radius: 4px;
  display: flex;
  align-items: center;
  transition: opacity var(--transition), color var(--transition);
}

.chat-item:hover .chat-item-delete {
  opacity: 1;
}

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

/* Main */
.main {
  flex: 1;
  display: flex;
  flex-direction: column;
  min-width: 0;
  background: var(--bg-primary);
}

.topbar {
  height: var(--topbar-height);
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 0 16px;
  border-bottom: 1px solid var(--border);
  flex-shrink: 0;
  background: var(--bg-secondary);
}

.topbar-title {
  flex: 1;
  font-size: 15px;
  font-weight: 600;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.topbar-actions {
  display: flex;
  gap: 4px;
}

/* Messages */
.messages-container {
  flex: 1;
  overflow-y: auto;
  scroll-behavior: smooth;
}

.welcome {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100%;
  min-height: 300px;
  text-align: center;
  padding: 40px 20px;
  color: var(--text-secondary);
}

.welcome.hidden {
  display: none;
}

.messages-container:has(.message) .welcome {
  display: none;
}

.welcome-icon {
  color: var(--accent);
  margin-bottom: 20px;
  opacity: 0.8;
}

.welcome h2 {
  font-size: 24px;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.welcome p {
  font-size: 14px;
}

.messages {
  max-width: 800px;
  margin: 0 auto;
  padding: 24px 20px 40px;
  width: 100%;
}

.message {
  display: flex;
  gap: 16px;
  margin-bottom: 24px;
  animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to { opacity: 1; transform: translateY(0); }
}

.message-avatar {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
  font-size: 14px;
  font-weight: 700;
}

.message.user .message-avatar {
  background: var(--accent-dim);
  color: var(--accent);
}

.message.assistant .message-avatar {
  background: #5436da22;
  color: #a78bfa;
}

.message-body {
  flex: 1;
  min-width: 0;
  padding-top: 4px;
}

.message-role {
  font-size: 12px;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 6px;
}

.message-content {
  font-size: 15px;
  line-height: 1.7;
  word-wrap: break-word;
  overflow-wrap: break-word;
}

.message-content p {
  margin-bottom: 12px;
}

.message-content p:last-child {
  margin-bottom: 0;
}

.message-content ul,
.message-content ol {
  margin: 8px 0 12px 20px;
}

.message-content li {
  margin-bottom: 4px;
}

.message-content h1,
.message-content h2,
.message-content h3 {
  margin: 16px 0 8px;
  font-weight: 600;
}

.message-content h1 { font-size: 1.4em; }
.message-content h2 { font-size: 1.2em; }
.message-content h3 { font-size: 1.05em; }

.message-content blockquote {
  border-right: 3px solid var(--accent);
  padding: 8px 16px;
  margin: 12px 0;
  color: var(--text-secondary);
  background: var(--bg-tertiary);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
}

.message-content a {
  color: var(--accent);
  text-decoration: none;
}

.message-content a:hover {
  text-decoration: underline;
}

.message-content table {
  border-collapse: collapse;
  margin: 12px 0;
  width: 100%;
  font-size: 14px;
}

.message-content th,
.message-content td {
  border: 1px solid var(--border);
  padding: 8px 12px;
  text-align: right;
}

.message-content th {
  background: var(--bg-tertiary);
}

/* Code blocks */
.message-content code {
  font-family: var(--mono);
  font-size: 0.88em;
  background: var(--bg-tertiary);
  padding: 2px 6px;
  border-radius: 4px;
  direction: ltr;
  unicode-bidi: embed;
}

.code-block-wrapper {
  position: relative;
  margin: 12px 0;
  border-radius: var(--radius-sm);
  overflow: hidden;
  border: 1px solid var(--border);
  direction: ltr;
}

.code-block-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 6px 12px;
  background: #1e1e1e;
  border-bottom: 1px solid var(--border);
  font-size: 12px;
  color: var(--text-secondary);
}

.code-block-lang {
  font-family: var(--mono);
  text-transform: lowercase;
}

.btn-copy-code {
  display: flex;
  align-items: center;
  justify-content: center;
  background: none;
  border: none;
  color: var(--text-secondary);
  width: 28px;
  height: 28px;
  border-radius: 4px;
  cursor: pointer;
  padding: 0;
  transition: all var(--transition);
}

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

.btn-copy-code.copied {
  color: var(--accent);
}

.code-block-wrapper pre {
  margin: 0 !important;
  padding: 16px !important;
  background: #1e1e1e !important;
  overflow-x: auto;
  font-size: 13px;
  line-height: 1.5;
}

.code-block-wrapper pre code {
  background: none;
  padding: 0;
  font-size: inherit;
}

/* Typing indicator */
.typing-indicator {
  display: flex;
  gap: 4px;
  padding: 8px 0;
}

.typing-indicator span {
  width: 8px;
  height: 8px;
  background: var(--text-muted);
  border-radius: 50%;
  animation: bounce 1.4s infinite ease-in-out both;
}

.typing-indicator span:nth-child(1) { animation-delay: -0.32s; }
.typing-indicator span:nth-child(2) { animation-delay: -0.16s; }

@keyframes bounce {
  0%, 80%, 100% { transform: scale(0.6); opacity: 0.4; }
  40% { transform: scale(1); opacity: 1; }
}

/* File attachment in message */
.message-files {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
  margin-bottom: 8px;
}

.file-badge {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 4px 10px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  border-radius: 20px;
  font-size: 12px;
  color: var(--text-secondary);
}

/* Input area */
.input-area {
  padding: 12px 20px 16px;
  border-top: 1px solid var(--border);
  background: var(--bg-secondary);
  flex-shrink: 0;
}

.attached-files {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
  margin-bottom: 8px;
  max-width: 800px;
  margin-left: auto;
  margin-right: auto;
}

.attached-file {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 10px;
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  font-size: 12px;
}

.attached-file-remove {
  background: none;
  border: none;
  color: var(--text-muted);
  cursor: pointer;
  padding: 0 2px;
  font-size: 16px;
  line-height: 1;
}

.attached-file-remove:hover {
  color: var(--danger);
}

.input-wrapper {
  display: flex;
  align-items: flex-end;
  gap: 8px;
  max-width: 800px;
  margin: 0 auto;
  background: var(--bg-tertiary);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 8px 12px;
  transition: border-color var(--transition), box-shadow var(--transition);
}

.input-wrapper:focus-within {
  border-color: var(--accent);
  box-shadow: 0 0 0 2px var(--accent-dim);
}

.input-left,
.input-right {
  display: flex;
  align-items: center;
  gap: 6px;
  flex-shrink: 0;
}

.message.user .message-content {
  direction: rtl;
  text-align: right;
  background: var(--user-msg-bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  padding: 12px 16px;
}

.message-content.rtl {
  direction: rtl;
  text-align: right;
}

.message-content.ltr {
  direction: ltr;
  text-align: left;
}

.message-input {
  flex: 1;
  background: none;
  border: none;
  outline: none;
  color: var(--text-primary);
  font-family: var(--font);
  font-size: 15px;
  line-height: 1.5;
  resize: none;
  max-height: 200px;
  min-height: 24px;
  padding: 4px 0;
  direction: rtl;
  text-align: right;
}

.message-input::placeholder {
  color: var(--text-muted);
}

/* Token ring */
.token-ring {
  position: relative;
  width: 32px;
  height: 32px;
  cursor: default;
  flex-shrink: 0;
}

.token-ring-svg {
  width: 100%;
  height: 100%;
  transform: rotate(-90deg);
}

.token-ring-bg {
  fill: none;
  stroke: var(--bg-hover);
  stroke-width: 3;
}

.token-ring-fill {
  fill: none;
  stroke: var(--accent);
  stroke-width: 3;
  stroke-linecap: round;
  stroke-dasharray: 97.4;
  stroke-dashoffset: 97.4;
  transition: stroke-dashoffset 0.4s ease, stroke 0.3s ease;
}

.token-ring.warning .token-ring-fill {
  stroke: var(--warning);
}

.token-ring.danger .token-ring-fill {
  stroke: var(--danger);
}

.token-ring-text {
  position: absolute;
  inset: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 7px;
  font-weight: 700;
  color: var(--text-secondary);
}

/* Model select */
.model-select {
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  color: var(--text-primary);
  padding: 6px 10px;
  border-radius: var(--radius-sm);
  font-size: 12px;
  font-family: var(--font);
  cursor: pointer;
  max-width: 200px;
  outline: none;
  direction: ltr;
}

.model-select:focus {
  border-color: var(--accent);
}

/* Buttons */
.btn-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  background: none;
  border: none;
  border-radius: var(--radius-sm);
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition);
  flex-shrink: 0;
}

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

.btn-new-chat {
  background: var(--accent-dim);
  color: var(--accent);
}

.btn-new-chat:hover {
  background: var(--accent);
  color: white;
}

.btn-attach {
  cursor: pointer;
}

.btn-send {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  background: var(--accent);
  border: none;
  border-radius: var(--radius-sm);
  color: white;
  cursor: pointer;
  transition: all var(--transition);
  flex-shrink: 0;
}

.btn-send:hover:not(:disabled) {
  background: var(--accent-hover);
}

.btn-send:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.input-hint {
  text-align: center;
  font-size: 11px;
  color: var(--text-muted);
  margin-top: 8px;
  max-width: 800px;
  margin-left: auto;
  margin-right: auto;
}

.input-hint.warning {
  color: var(--warning);
}

.input-hint.danger {
  color: var(--danger);
}

/* Scrollbar */
::-webkit-scrollbar {
  width: 6px;
  height: 6px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: var(--border);
  border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
  background: var(--text-muted);
}

/* Sidebar overlay (mobile) */
.sidebar-overlay {
  display: none;
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.55);
  z-index: 99;
  opacity: 0;
  transition: opacity var(--transition);
}

.sidebar-overlay.visible {
  display: block;
  opacity: 1;
}

.btn-close-sidebar {
  display: none;
}

/* Responsive */
@media (max-width: 768px) {
  .sidebar {
    position: fixed;
    right: 0;
    top: 0;
    bottom: 0;
    z-index: 100;
    box-shadow: var(--shadow);
    transform: translateX(0);
    transition: transform var(--transition), box-shadow var(--transition);
    width: var(--sidebar-width);
    min-width: var(--sidebar-width);
    opacity: 1;
    pointer-events: auto;
    margin-right: 0;
  }

  .sidebar.collapsed {
    transform: translateX(100%);
    width: var(--sidebar-width);
    min-width: var(--sidebar-width);
    margin-right: 0;
    opacity: 1;
    pointer-events: none;
  }

  .btn-close-sidebar {
    display: flex;
    margin-right: auto;
  }

  .model-select {
    max-width: 120px;
    font-size: 11px;
  }

  .messages {
    padding: 16px 12px 32px;
  }

  .input-area {
    padding: 8px 12px 12px;
  }
}