:root {
  --bg-body: #f3f4f6;
  --text-main: #1f2937;
  --text-muted: #4b5563;
  --text-hint: #6b7280;
  --bg-panel: #ffffff;
  --border-color: #d1d5db;
  --bg-element: #e5e7eb;
  --bg-element-hover: #d1d5db;
  --bg-row-active: #e0f2fe;
  --border-row-active: #2f6fed;
  --bg-btn: #f3f4f6;
  --bg-btn-hover: #e5e7eb;
  --bg-remove: #fee2e2;
  --bg-remove-hover: #fca5a5;
  --text-remove: #991b1b;
  --border-input: #d1d5db;
  --bg-overlay: rgba(255, 255, 255, 0.85);
  --bg-preview: #f9fafb;
  --border-preview: #d1d5db;
  --color-ok: #16a34a;
  --color-error: #dc2626;
}
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --bg-body: #111;
    --text-main: #f5f5f5;
    --text-muted: #cfcfcf;
    --text-hint: #a5a5a5;
    --bg-panel: #141414;
    --border-color: #2c2c2c;
    --bg-element: #1f1f1f;
    --bg-element-hover: #2a2a2a;
    --bg-row-active: #1e2a48;
    --border-row-active: #2f6fed;
    --bg-btn: #252525;
    --bg-btn-hover: #2d2d2d;
    --bg-remove: #452222;
    --bg-remove-hover: #612c2c;
    --text-remove: #ff9999;
    --border-input: #2f2f2f;
    --bg-overlay: rgba(8, 8, 8, 0.82);
    --bg-preview: #0d0d0d;
    --border-preview: #333;
    --color-ok: #5be37d;
    --color-error: #ff7676;
  }
}
:root[data-theme="dark"] {
    --bg-body: #111;
    --text-main: #f5f5f5;
    --text-muted: #cfcfcf;
    --text-hint: #a5a5a5;
    --bg-panel: #141414;
    --border-color: #2c2c2c;
    --bg-element: #1f1f1f;
    --bg-element-hover: #2a2a2a;
    --bg-row-active: #1e2a48;
    --border-row-active: #2f6fed;
    --bg-btn: #252525;
    --bg-btn-hover: #2d2d2d;
    --bg-remove: #452222;
    --bg-remove-hover: #612c2c;
    --text-remove: #ff9999;
    --border-input: #2f2f2f;
    --bg-overlay: rgba(8, 8, 8, 0.82);
    --bg-preview: #0d0d0d;
    --border-preview: #333;
    --color-ok: #5be37d;
    --color-error: #ff7676;
}
.theme-toggle-btn {
  background: transparent;
  border: 1px solid var(--border-color);
  color: var(--text-main);
  font-size: 1.4rem;
  cursor: pointer;
  padding: 6px 12px;
  border-radius: 999px;
  transition: background 0.2s;
}
.theme-toggle-btn:hover {
  background: var(--bg-element);
}
:root { color-scheme: light dark;
      font-family: "Segoe UI", system-ui, -apple-system, BlinkMacSystemFont, sans-serif;
      background: var(--bg-body);
      color: var(--text-main);
    }

    body {
      margin: 0;
      min-height: 100vh;
      display: flex;
      justify-content: center;
      padding: 32px 16px 48px;
      position: relative;
      transition: background 200ms ease;
    }

    #dropOverlay {
      position: fixed;
      inset: 0;
      background: var(--bg-overlay);
      border: 2px dashed #2f6fed;
      color: var(--text-main);
      font-size: clamp(1.2rem, 3vw, 2rem);
      letter-spacing: 0.04em;
      display: none;
      justify-content: center;
      align-items: center;
      z-index: 9999;
      pointer-events: none;
      text-transform: uppercase;
    }

    body.drag-active #dropOverlay {
      display: flex;
      pointer-events: all;
    }

    main {
      width: min(1200px, 100%);
      display: flex;
      flex-direction: column;
      gap: 24px;
    }

    h1 {
      font-size: clamp(1.8rem, 3vw, 2.4rem);
      margin: 0;
    }

    .lead-steps {
      margin: 8px 0 0;
      padding-left: 20px;
      color: var(--text-muted);
      font-size: 0.95rem;
      font-weight: 400;
      display: flex;
      flex-direction: column;
      gap: 4px;
    }

    .lead-steps li {
      margin: 0;
    }

    .controls,
    .actions {
      display: flex;
      flex-wrap: wrap;
      gap: 12px;
      align-items: center;
    }

    label.file-picker {
      display: inline-flex;
      align-items: center;
      gap: 10px;
      padding: 12px 18px;
      border-radius: 999px;
      background: var(--bg-element);
      border: 1px solid var(--border-input);
      cursor: pointer;
      transition: background 120ms;
    }

    label.file-picker:hover {
      background: var(--bg-element-hover);
    }

    label.file-picker input {
      display: none;
    }

    button {
      border: none;
      border-radius: 999px;
      padding: 10px 18px;
      font-size: 0.95rem;
      cursor: pointer;
      background: #2f6fed;
      color: white;
      transition: opacity 140ms, transform 140ms;
    }

    button:disabled {
      opacity: 0.4;
      cursor: not-allowed;
    }

    .workspace {
      display: grid;
      grid-template-columns: minmax(260px, var(--list-panel-width, 1fr)) auto minmax(320px, 2fr);
      gap: 24px;
      column-gap: 18px;
      align-items: stretch;
    }

    .splitter {
      width: 12px;
      border-radius: 999px;
      background: var(--bg-element);
      border: 1px solid var(--border-color);
      cursor: col-resize;
      position: relative;
      min-height: 100%;
    }

    .splitter::after {
      content: '';
      position: absolute;
      inset: 20% 3px;
      border-radius: 999px;
      background: #2f6fed;
      opacity: 0;
      transition: opacity 140ms ease;
    }

    .splitter:hover::after,
    .splitter:focus-visible::after,
    .splitter.resizing::after {
      opacity: 0.85;
    }

    .panel {
      background: var(--bg-panel);
      border: 1px solid var(--border-color);
      border-radius: 18px;
      padding: 20px;
      display: flex;
      flex-direction: column;
      gap: 16px;
    }

    #fileList {
      list-style: none;
      margin: 0;
      padding: 0;
      display: flex;
      flex-direction: column;
      gap: 10px;
      min-height: 80px;
    }

    .file-row {
      display: flex;
      flex-direction: column;
      gap: 8px;
      padding: 10px 12px;
      border-radius: 12px;
      background: var(--bg-element);
      border: 1px solid transparent;
      cursor: grab;
    }

    .file-row-main {
      display: grid;
      grid-template-columns: 24px 1fr auto;
      gap: 10px;
      align-items: center;
    }

    .file-row.dragging {
      opacity: 0.6;
    }

    .file-row.active {
      border-color: #2f6fed;
      background: var(--bg-row-active);
    }

    .file-row .index {
      font-variant-numeric: tabular-nums;
      font-weight: 600;
      color: var(--text-hint);
    }

    .file-row .name {
      overflow: hidden;
      text-overflow: ellipsis;
      white-space: nowrap;
    }

    .file-row .buttons {
      display: flex;
      gap: 6px;
    }

    .file-row .buttons button {
      padding: 6px 10px;
      border-radius: 8px;
      font-size: 0.8rem;
      background: var(--bg-btn);
    }

    .file-row .buttons button:hover {
      background: var(--bg-btn-hover);
    }

    .file-row .buttons .remove-btn {
      background: var(--bg-remove);
    }

    .file-row .buttons .remove-btn:hover {
      background: var(--bg-remove-hover);
    }

    .range-control {
      display: flex;
      align-items: center;
      gap: 8px;
      font-size: 0.8rem;
      color: var(--text-muted);
    }

    .range-input {
      flex: 1;
      border: 1px solid var(--border-input);
      background: var(--bg-panel);
      color: var(--text-main);
      border-radius: 999px;
      padding: 6px 12px;
      font-size: 0.9rem;
      font-family: inherit;
    }

    .range-input:focus {
      outline: none;
      border-color: #2f6fed;
      box-shadow: 0 0 0 2px rgba(47, 111, 237, 0.25);
    }

    .range-input.invalid {
      border-color: var(--color-error);
      box-shadow: 0 0 0 2px rgba(255, 118, 118, 0.2);
    }

    .hint {
      font-size: 0.85rem;
      color: var(--text-hint);
    }

    .preview-wrapper {
      position: relative;
      flex: 1;
      border-radius: 12px;
      overflow: hidden;
      background: var(--bg-preview);
      border: 1px dashed var(--border-preview);
      min-height: 420px;
    }

    #pdfPreview {
      width: 100%;
      height: 100%;
      border: none;
    }

    #status {
      min-height: 24px;
      font-size: 0.95rem;
    }

    #status.ok {
      color: var(--color-ok);
    }

    #status.error {
      color: var(--color-error);
    }

    body.drag-active .preview-wrapper,
    body.drag-active .preview-wrapper *,
    body.resizing-active .preview-wrapper,
    body.resizing-active .preview-wrapper * {
      pointer-events: none !important;
    }

    .changelog-section {
      background: var(--bg-panel);
      border: 1px solid var(--border-color);
      border-radius: 18px;
      padding: 18px 22px;
      display: flex;
      flex-direction: column;
      gap: 8px;
    }

    .changelog-section summary {
      cursor: pointer;
      outline: none;
    }

    .changelog-section h2 {
      display: inline-block;
      margin: 0;
      font-size: 1rem;
      letter-spacing: 0.05em;
      text-transform: uppercase;
      color: var(--text-muted);
    }

    .changelog-section ul {
      list-style: none;
      margin: 12px 0 0 0;
      padding: 0;
      display: flex;
      flex-direction: column;
      gap: 4px;
    }

    .changelog-section li {
      font-size: 0.95rem;
      color: var(--text-muted);
    }

    .changelog-section li strong {
      color: var(--text-main);
      margin-right: 8px;
    }

    @media (max-width: 900px) {
      .workspace {
        grid-template-columns: 1fr;
        gap: 20px;
      }
      .splitter {
        display: none;
      }
      .preview-wrapper {
        min-height: 320px;
      }
    }

    #docRenderRoot {
      position: fixed;
      top: -10000px;
      left: -10000px;
      width: 794px;
      min-height: 1123px;
      padding: 40px 30px;
      background: #ffffff;
      color: #000000;
      pointer-events: none;
      opacity: 0;
      z-index: -1;
      font-family: "Calibri", "Segoe UI", system-ui, sans-serif;
      line-height: 1.4;
    }

    #docRenderRoot * {
      box-sizing: border-box;
    }

    #docRenderRoot .docx-wrapper {
      box-shadow: none !important;
      margin: 0 !important;
      padding: 0 !important;
      background: transparent !important;
    }

    #docRenderRoot .docx {
      background: #ffffff !important;
    }

#loadingOverlay {
  position: fixed;
  top: 24px;
  right: 24px;
  background: var(--bg-panel);
  border: 1px solid var(--border-color);
  color: var(--text-main);
  padding: 16px 20px;
  border-radius: 12px;
  display: flex;
  align-items: center;
  gap: 16px;
  z-index: 9999;
  box-shadow: 0 8px 24px rgba(0,0,0,0.5);
  opacity: 0;
  pointer-events: none;
  transform: translateY(-10px);
  transition: opacity 0.2s, transform 0.2s;
  font-size: 1rem;
}

#loadingOverlay.active {
  opacity: 1;
  pointer-events: all;
  transform: translateY(0);
}

.spinner {
  width: 24px;
  height: 24px;
  border: 3px solid rgba(47, 111, 237, 0.3);
  border-top-color: #2f6fed;
  border-radius: 50%;
  animation: rotation 0.8s linear infinite;
}

@keyframes rotation {
  from { transform: rotate(0deg); }
  to { transform: rotate(360deg); }
}