/* ===== Color Tokens ===== */
:root {
  --bg: #f0eef6;
  --surface: #ffffff;
  --surface-hover: #f5f3fb;
  --border: #ddd8ee;
  --border-light: #eae6f5;
  --text: #1a1a2e;
  --text-secondary: #6e6b85;
  --text-tertiary: #9896b0;
  --accent: #7c5cfc;
  --accent-light: #ece7ff;
  --accent-lighter: #f5f2ff;
  --accent-dark: #6344e0;
  --danger: #e04d6b;
  --shadow-sm: 0 1px 4px rgba(26, 26, 46, 0.06);
  --shadow-md: 0 4px 16px rgba(26, 26, 46, 0.08);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 20px;
  --radius-full: 24px;
  --transition: all 0.2s ease;

  /* Dark sidebar tokens */
  --sidebar-bg: #1a1a2e;
  --sidebar-surface: #232342;
  --sidebar-border: #2d2b50;
  --sidebar-text: #ffffff;
  --sidebar-text-secondary: #9896b0;
  --sidebar-hover: #2a2a4a;
}

/* ===== App Shell ===== */
.app {
  display: flex;
  flex-direction: column;
  height: 100vh;
  background: var(--bg);
}

.app-header {
  display: flex;
  align-items: baseline;
  gap: 12px;
  padding: 16px 28px;
  border-bottom: 1px solid var(--sidebar-border);
  background: var(--sidebar-bg);
}

.app-header__logo {
  font-size: 20px;
  font-weight: 700;
  color: #ffffff;
  letter-spacing: -0.02em;
}

.app-header__tagline {
  font-size: 13px;
  color: var(--sidebar-text-secondary);
}

.app-main {
  display: flex;
  flex: 1;
  overflow: hidden;
}

/* Loading */
.app-loading {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100vh;
  gap: 16px;
  color: var(--text-secondary);
  background: var(--sidebar-bg);
}

.app-loading__spinner {
  width: 32px;
  height: 32px;
  border: 3px solid var(--border);
  border-top-color: var(--accent);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

/* ===== Upload Panel (Left Sidebar) ===== */
.upload-panel {
  width: 340px;
  min-width: 340px;
  display: flex;
  flex-direction: column;
  gap: 20px;
  padding: 24px;
  border-right: 1px solid var(--sidebar-border);
  background: var(--sidebar-bg);
  overflow-y: auto;
}

.upload-panel__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.upload-panel__title {
  font-size: 16px;
  font-weight: 600;
  color: var(--sidebar-text);
}

.upload-panel__badge {
  font-size: 12px;
  font-weight: 500;
  color: var(--accent);
  background: rgba(124, 92, 252, 0.15);
  padding: 2px 10px;
  border-radius: var(--radius-full);
}

.upload-panel__hint {
  padding: 16px;
  text-align: center;
  color: var(--sidebar-text-secondary);
  font-size: 13px;
  line-height: 1.6;
}

/* ===== Upload Zone ===== */
.upload-zone {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 32px 20px;
  border: 2px dashed var(--sidebar-border);
  border-radius: var(--radius-lg);
  cursor: pointer;
  transition: var(--transition);
  background: var(--sidebar-surface);
}

.upload-zone:hover {
  border-color: var(--accent);
  background: rgba(124, 92, 252, 0.08);
}

.upload-zone--dragging {
  border-color: var(--accent);
  border-style: solid;
  background: rgba(124, 92, 252, 0.12);
  transform: scale(1.01);
}

.upload-zone--disabled {
  opacity: 0.5;
  pointer-events: none;
}

.upload-zone__icon {
  color: var(--accent);
  opacity: 0.7;
}

.upload-zone--dragging .upload-zone__icon {
  opacity: 1;
  transform: translateY(-2px);
  transition: var(--transition);
}

.upload-zone__text {
  font-size: 14px;
  font-weight: 500;
  color: var(--sidebar-text);
}

.upload-zone__subtext {
  font-size: 13px;
  color: var(--sidebar-text-secondary);
}

.upload-zone__browse {
  color: var(--accent);
  font-weight: 500;
  text-decoration: underline;
  text-underline-offset: 2px;
}

.upload-zone__formats {
  font-size: 11px;
  color: var(--sidebar-text-secondary);
  margin-top: 4px;
}

/* ===== File List ===== */
.file-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.file-list__title {
  font-size: 12px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--sidebar-text-secondary);
  margin-bottom: 4px;
}

.file-list__items {
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.file-item {
  display: grid;
  grid-template-columns: auto 1fr auto;
  align-items: center;
  gap: 10px;
  padding: 10px 12px;
  background: var(--sidebar-surface);
  border-radius: var(--radius-md);
  position: relative;
  overflow: hidden;
  transition: var(--transition);
}

.file-item--done {
  background: rgba(124, 92, 252, 0.1);
}

.file-item--error {
  background: rgba(224, 77, 107, 0.1);
}

.file-item__icon {
  color: var(--sidebar-text-secondary);
  display: flex;
}

.file-item--done .file-item__icon {
  color: var(--accent);
}

.file-item__info {
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.file-item__name {
  font-size: 13px;
  font-weight: 500;
  color: var(--sidebar-text);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.file-item__meta {
  font-size: 11px;
  color: var(--sidebar-text-secondary);
}

.file-item__status {
  display: flex;
  align-items: center;
  gap: 4px;
}

.file-item__check {
  color: var(--accent);
}

.file-item__error-icon {
  color: var(--danger);
}

.file-item__progress-ring {
  display: flex;
  align-items: center;
  gap: 4px;
}

.file-item__percent {
  font-size: 11px;
  color: var(--sidebar-text-secondary);
}

.file-item__progress-bar {
  grid-column: 1 / -1;
  height: 3px;
  background: var(--sidebar-border);
  border-radius: 2px;
  overflow: hidden;
}

.file-item__progress-fill {
  height: 100%;
  background: var(--accent);
  border-radius: 2px;
  transition: width 0.3s ease;
}

.file-item__error {
  grid-column: 1 / -1;
  font-size: 12px;
  color: var(--danger);
}

/* ===== Chat Panel (Right) ===== */
.chat-panel {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  background: var(--bg);
}

.chat-panel__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 28px;
  border-bottom: 1px solid var(--border);
  background: var(--surface);
}

.chat-panel__title {
  font-size: 16px;
  font-weight: 600;
  color: var(--text);
}

.chat-panel__clear {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  font-size: 13px;
  font-weight: 500;
  color: var(--text-secondary);
  background: none;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: var(--transition);
}

.chat-panel__clear:hover {
  color: var(--danger);
  border-color: var(--danger);
  background: rgba(224, 77, 107, 0.06);
}

.chat-panel__messages {
  flex: 1;
  overflow-y: auto;
  padding: 24px 28px;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

/* Empty state */
.chat-panel__empty {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 12px;
  color: var(--text-tertiary);
  text-align: center;
  padding: 40px;
}

.chat-panel__empty h3 {
  font-size: 18px;
  font-weight: 600;
  color: var(--text-secondary);
}

.chat-panel__empty p {
  font-size: 14px;
  max-width: 400px;
  line-height: 1.6;
}

/* ===== Chat Messages ===== */
.chat-message {
  display: flex;
  gap: 12px;
  max-width: 780px;
}

.chat-message--user {
  align-self: flex-end;
  flex-direction: row-reverse;
}

.chat-message--assistant {
  align-self: flex-start;
}

.chat-message__avatar {
  width: 32px;
  height: 32px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.chat-message--user .chat-message__avatar {
  background: var(--accent-light);
  color: var(--accent);
}

.chat-message--assistant .chat-message__avatar {
  background: var(--border-light);
  color: var(--text-secondary);
}

.chat-message__body {
  display: flex;
  flex-direction: column;
  gap: 8px;
  min-width: 0;
  max-width: 640px;
}

.chat-message__bubble {
  padding: 12px 16px;
  border-radius: var(--radius-xl);
  font-size: 14px;
  line-height: 1.65;
  word-wrap: break-word;
}

.chat-message--user .chat-message__bubble {
  background: var(--accent-light);
  color: var(--text);
  border-bottom-right-radius: var(--radius-sm);
}

.chat-message--assistant .chat-message__bubble {
  background: var(--surface);
  color: var(--text);
  border-bottom-left-radius: var(--radius-sm);
  border: 1px solid var(--border);
  box-shadow: var(--shadow-sm);
}

/* Markdown inside assistant bubbles */
.chat-message--assistant .chat-message__bubble p {
  margin-bottom: 8px;
}

.chat-message--assistant .chat-message__bubble p:last-child {
  margin-bottom: 0;
}

.chat-message--assistant .chat-message__bubble code {
  font-size: 13px;
  background: var(--bg);
  padding: 2px 6px;
  border-radius: 4px;
  font-family: 'SF Mono', 'Fira Code', monospace;
}

.chat-message--assistant .chat-message__bubble pre {
  background: #1a1a2e;
  color: #d4d0f0;
  padding: 12px 16px;
  border-radius: var(--radius-sm);
  overflow-x: auto;
  margin: 8px 0;
}

.chat-message--assistant .chat-message__bubble pre code {
  background: none;
  padding: 0;
  color: inherit;
}

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

.chat-message--assistant .chat-message__bubble li {
  margin-bottom: 4px;
}

.chat-message--assistant .chat-message__bubble strong {
  font-weight: 600;
}

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

.typing-indicator span {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  background: var(--text-tertiary);
  animation: bounce 1.2s ease-in-out infinite;
}

.typing-indicator span:nth-child(2) {
  animation-delay: 0.1s;
}

.typing-indicator span:nth-child(3) {
  animation-delay: 0.2s;
}

@keyframes bounce {
  0%, 60%, 100% { transform: translateY(0); }
  30% { transform: translateY(-6px); }
}

/* ===== Chat Input ===== */
.chat-input {
  padding: 16px 28px 20px;
  background: var(--surface);
  border-top: 1px solid var(--border);
}

.chat-input__wrapper {
  display: flex;
  align-items: flex-end;
  gap: 8px;
  padding: 10px 14px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-full);
  transition: var(--transition);
}

.chat-input__wrapper:focus-within {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(124, 92, 252, 0.12);
}

.chat-input__textarea {
  flex: 1;
  border: none;
  outline: none;
  background: none;
  font-family: inherit;
  font-size: 14px;
  line-height: 1.5;
  color: var(--text);
  resize: none;
  max-height: 160px;
  padding: 2px 0;
}

.chat-input__textarea::placeholder {
  color: var(--text-tertiary);
}

.chat-input__textarea:disabled {
  opacity: 0.5;
}

.chat-input__send {
  width: 34px;
  height: 34px;
  border: none;
  border-radius: 50%;
  background: var(--accent);
  color: white;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  flex-shrink: 0;
  transition: var(--transition);
}

.chat-input__send:hover:not(:disabled) {
  background: var(--accent-dark);
  transform: scale(1.05);
}

.chat-input__send:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.chat-input__hint {
  text-align: center;
  font-size: 11px;
  color: var(--text-tertiary);
  margin-top: 8px;
}

.chat-input__hint kbd {
  font-family: inherit;
  font-size: 11px;
  background: var(--border-light);
  padding: 1px 5px;
  border-radius: 3px;
  border: 1px solid var(--border);
}

/* ===== Message Actions ===== */
.message-actions {
  display: flex;
  gap: 4px;
  opacity: 0;
  transition: opacity 0.15s ease;
}

.chat-message:hover .message-actions,
.message-actions:focus-within {
  opacity: 1;
}

.message-action {
  display: flex;
  align-items: center;
  gap: 4px;
  padding: 4px 10px;
  font-size: 12px;
  font-weight: 500;
  color: var(--text-secondary);
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: var(--transition);
}

.message-action:hover {
  color: var(--text);
  background: var(--surface-hover);
  border-color: var(--text-tertiary);
}

/* ===== Source Badges ===== */
.source-badges {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.source-badge {
  display: inline-flex;
  align-items: center;
  gap: 5px;
  padding: 4px 10px;
  font-size: 12px;
  font-weight: 500;
  color: var(--text-secondary);
  background: var(--border-light);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: var(--transition);
}

.source-badge:hover {
  background: var(--accent-lighter);
  border-color: var(--accent);
  color: var(--accent);
}

.source-badge__page {
  color: var(--text-tertiary);
  font-size: 11px;
}

/* ===== Why Drawer ===== */
.why-drawer {
  border-radius: var(--radius-md);
  overflow: hidden;
}

.why-drawer__toggle {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 10px;
  font-size: 12px;
  font-weight: 500;
  color: var(--text-secondary);
  background: none;
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: var(--transition);
  width: fit-content;
}

.why-drawer__toggle:hover {
  background: var(--surface-hover);
  color: var(--text);
}

.why-drawer__content {
  margin-top: 8px;
  padding: 16px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  animation: slideDown 0.2s ease;
}

@keyframes slideDown {
  from {
    opacity: 0;
    transform: translateY(-4px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.why-drawer__summary {
  font-size: 13px;
  color: var(--text-secondary);
  margin-bottom: 12px;
}

.why-drawer__chunks {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.chunk-card {
  padding: 12px;
  background: var(--bg);
  border: 1px solid var(--border);
  border-radius: var(--radius-sm);
  transition: var(--transition);
}

.chunk-card--focused {
  border-color: var(--accent);
  background: var(--accent-lighter);
}

.chunk-card__header {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 8px;
  margin-bottom: 8px;
}

.chunk-card__id {
  font-size: 11px;
  font-weight: 600;
  color: var(--text-tertiary);
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.chunk-card__source {
  font-size: 12px;
  font-weight: 500;
  color: var(--text-secondary);
}

.chunk-card__relevance {
  margin-left: auto;
  font-size: 11px;
  font-weight: 600;
  color: var(--accent);
  background: var(--accent-lighter);
  padding: 2px 8px;
  border-radius: var(--radius-full);
}

.chunk-card__preview {
  font-size: 12px;
  color: var(--text-secondary);
  line-height: 1.6;
  white-space: pre-wrap;
  word-break: break-word;
}

.highlight {
  background: #e0d4ff;
  color: var(--text);
  padding: 0 2px;
  border-radius: 2px;
}

/* ===== Chunk Type Badges ===== */
.chunk-card__type-icon {
  vertical-align: -2px;
  margin-right: 3px;
}

.chunk-card__type-icon--table {
  color: #7c5cfc;
}

.chunk-card__type-icon--figure {
  color: #e07c3e;
}

.chunk-card__type-badge {
  font-size: 10px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  padding: 2px 8px;
  border-radius: var(--radius-full);
}

.chunk-card__type-badge--table {
  background: rgba(124, 92, 252, 0.12);
  color: #7c5cfc;
}

.chunk-card__type-badge--figure {
  background: rgba(224, 124, 62, 0.12);
  color: #e07c3e;
}

/* ===== Multimodal Asset Previews ===== */
.chunk-card__asset-preview {
  margin: 8px 0;
  border-radius: var(--radius-sm);
  overflow: hidden;
  border: 1px solid var(--border);
  background: var(--surface);
}

.chunk-card__asset-img {
  display: block;
  width: 100%;
  max-height: 240px;
  object-fit: contain;
  background: #fff;
}

/* ===== Source Badge Variants ===== */
.source-badge--table {
  border-color: rgba(124, 92, 252, 0.3);
}

.source-badge--table:hover {
  background: rgba(124, 92, 252, 0.1);
  border-color: #7c5cfc;
  color: #7c5cfc;
}

.source-badge--figure {
  border-color: rgba(224, 124, 62, 0.3);
}

.source-badge--figure:hover {
  background: rgba(224, 124, 62, 0.1);
  border-color: #e07c3e;
  color: #e07c3e;
}

/* ===== Why Drawer Stats ===== */
.why-drawer__stat {
  display: inline-flex;
  align-items: center;
  gap: 3px;
  margin-left: 8px;
  font-size: 12px;
  color: var(--text-tertiary);
}

/* ===== Upload Panel Limits ===== */
.upload-panel__limit-msg {
  font-size: 12px;
  color: var(--danger);
  text-align: center;
  padding: 6px 0;
}

.upload-panel__limits-info {
  font-size: 11px;
  color: var(--sidebar-text-secondary);
  margin-top: 4px;
  opacity: 0.7;
}

/* ===== Spinner Utility ===== */
@keyframes spin {
  to { transform: rotate(360deg); }
}

.spin {
  animation: spin 1s linear infinite;
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
  .app-main {
    flex-direction: column;
  }

  .upload-panel {
    width: 100%;
    min-width: unset;
    max-height: 280px;
    border-right: none;
    border-bottom: 1px solid var(--sidebar-border);
  }

  .chat-panel__messages {
    padding: 16px;
  }

  .chat-input {
    padding: 12px 16px 16px;
  }

  .chat-message__body {
    max-width: calc(100vw - 80px);
  }
}