body {
      background: #f7f9fc;
      font-family: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
      color: #111827;
    }

    .navbar {
      background: #ffffff;
      border-bottom: 1px solid #e5e7eb;
    }
    .navbar-brand {
      font-weight: 700;
      color: #111827 !important;
      font-size: 1.15rem;
      letter-spacing: .04em;
    }
    .nav-link {
      color: #4b5563 !important;
      font-size: .9rem;
      padding-left: 1rem !important;
      padding-right: 1rem !important;
    }
    .nav-link:hover, .nav-link.active {
      color: #111827 !important;
    }

    main {
      padding: 40px 0 45px;
    }
    .tool-wrapper {
      max-width: 1120px;
    }

    .tool-card-main {
      background: #ffffff;
      border-radius: 18px;
      border: 1px solid #e5e7eb;
      box-shadow: 0 18px 45px rgba(15, 23, 42, 0.06);
      overflow: hidden;
    }
    .tool-card-header {
      padding: 20px 22px 14px;
      border-bottom: 1px solid #e5e7eb;
    }
    .tool-label {
      font-size: .8rem;
      color: #6b7280;
      margin-bottom: 4px;
    }
    .tool-title {
      font-size: 1.2rem;
      font-weight: 700;
      margin-bottom: 4px;
      color: #111827;
    }
    .tool-desc {
      font-size: .86rem;
      color: #6b7280;
      margin-bottom: 0;
    }

    .badge-soft {
      font-size: .75rem;
      padding: 4px 8px;
      border-radius: 999px;
      background: #eff6ff;
      color: #1d4ed8;
      border: 1px solid #bfdbfe;
      display: inline-block;
    }

    .badge-soft-alt {
      font-size: .75rem;
      padding: 4px 8px;
      border-radius: 999px;
      background: #ecfdf5;
      color: #15803d;
      border: 1px solid #bbf7d0;
      display: inline-block;
      margin-top: 4px;
    }

    .tool-card-body {
      padding: 18px 22px 20px;
    }

    .form-shell {
      background: #f9fafb;
      border-radius: 14px;
      border: 1px solid #e5e7eb;
      padding: 14px 14px 16px;
    }

    .section-title {
      font-size: .9rem;
      font-weight: 600;
      margin-bottom: 8px;
      color: #111827;
    }

    .form-label {
      font-size: .8rem;
      margin-bottom: 4px;
      color: #374151;
    }
    .form-text {
      font-size: .75rem;
      color: #6b7280;
    }

    .form-control, .form-select {
      font-size: .83rem;
    }
    input[type="range"] {
      accent-color: #2563eb;
    }

    .btn-primary-dr {
      --bs-btn-color: #fff;
      --bs-btn-hover-color: #fff;
      --bs-btn-hover-bg: #1d4ed8;
      --bs-btn-active-color: #fff;
      --bs-btn-active-bg: #1d4ed8;
      --bs-btn-disabled-color: #fff;
      --bs-btn-disabled-bg: #2563eb;
      color: #fff;
      width: 100%;
      border-radius: 10px;
      background: #2563eb;
      border: none;
      font-size: .9rem;
      padding: 9px 14px;
      font-weight: 500;
    }
    .btn-primary-dr:disabled {
      opacity: .75;
    }

    .alert-error {
      margin-top: 10px;
      font-size: .8rem;
    }

    .preview-card {
      background: #f9fafb;
      border-radius: 14px;
      border: 1px solid #e5e7eb;
      padding: 12px;
      min-height: 190px;
      display: flex;
      flex-direction: column;
    }

    .preview-header {
      display: flex;
      justify-content: space-between;
      align-items: center;
      font-size: .8rem;
      color: #6b7280;
      margin-bottom: 8px;
    }

    .preview-image-box {
      border-radius: 12px;
      border: 1px solid #e5e7eb;
      background: #ffffff;
      padding: 6px;
      display: flex;
      align-items: center;
      justify-content: center;
      max-height: 220px;
      overflow: hidden;
    }
    .preview-image-box img {
      max-width: 100%;
      max-height: 200px;
      object-fit: contain;
    }

    .preview-meta {
      margin-top: 6px;
      font-size: .8rem;
      color: #4b5563;
    }
    .preview-meta strong {
      color: #111827;
    }

    .btn-download {
      margin-top: 8px;
      font-size: .85rem;
      width: 100%;
      border-radius: 8px;
    }

    .batch-table {
      font-size: .8rem;
    }
    .batch-table th,
    .batch-table td {
      vertical-align: middle;
    }

    .thumb-cell {
      width: 72px;
    }
    .thumb-box {
      width: 60px;
      height: 45px;
      border-radius: 8px;
      overflow: hidden;
      border: 1px solid #e5e7eb;
      background: #ffffff;
      display: flex;
      align-items: center;
      justify-content: center;
    }
    .thumb-box img {
      max-width: 100%;
      max-height: 100%;
      object-fit: contain;
    }

    footer {
      border-top: 1px solid #e5e7eb;
      padding: 18px 0;
      font-size: .8rem;
      color: #6b7280;
    }
    footer a {
      margin-inline: 6px;
      color: #374151;
      text-decoration: none;
    }
    footer a:hover {
      text-decoration: underline;
    }

    /* Drag & Drop Upload */
    .dr-dropzone{
      border: 1px dashed #cbd5e1;
      border-radius: 12px;
      padding: 12px;
      background: #ffffff;
      transition: box-shadow .15s ease, border-color .15s ease, background .15s ease;
      cursor: pointer;
    }
    .dr-dropzone.dragover{
      border-color:#2563eb;
      background:#eff6ff;
      box-shadow: 0 0 0 4px rgba(37,99,235,.12);
    }
    .dr-drop-hint{
      font-size: .75rem;
      color:#6b7280;
      margin-top:6px;
    }
    .dr-dropzone input[type="file"]{
      cursor:pointer;
    }