/* Scoped variables (only inside #pdf-merger-tool) */
#pdf-merger-tool {
    --pm-primary: #018AE7;
    --pm-primary-2: #0081D9;
    --pm-muted: #58565c;
    --pm-text: #1e1c1c;
    --pm-bg: #88c8e8;
    --pm-card: #ffffff;
  }

    /* Light blue behind the white card */
    body {
    background-color: #c8e7fc; 
    }
  
  /* Card wrapper (keeps the same card look you had before) */
  #pdf-merger-tool {
    max-width: 1500px;
    margin: 18px auto;
    padding: 36px;
    background: var(--pm-card);
    border-radius: 8px;
    box-shadow: 0 14px 36px rgba(0, 0, 0, 0.1);
    border: 1px solid rgba(47,51,53,0.04);
    color: var(--pm-text);
    font-family: "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    box-sizing: border-box;
  }
  
  /* Title */
  #pdf-merger-tool h1 {
    margin: 0 0 18px 0;
    font-size: 60px;
    color: var(--pm-primary);
    font-weight: 800;
    text-align: center;
    letter-spacing: 0.4px;
    text-transform: uppercase;
  }
  
  /* Form container: use normal block flow (vertical stacking) */
  #pdf-merger-tool #pdfForm {
    width: 80%;
    max-width: 1200px;
    margin: 6px auto 0 auto;
    box-sizing: border-box;
    display: block; /* explicitly block so children flow vertically */
  }
  
  /* Labels (tighter spacing) */
  #pdf-merger-tool #pdfForm label {
    display: block;
    font-weight: 700;
    color: var(--pm-muted);
    margin: 8px 0 6px 0; /* reduced spacing */
    font-size: 20px;
    letter-spacing: 0.2px;
    text-align: center; /* keep label centered above inputs */
  }

  /* Required field indicator */
  #pdf-merger-tool #pdfForm label .required {
    color: #e74c3c;
    margin-left: 2px;
  }

  /* Help icon */
  #pdf-merger-tool #pdfForm label .help-icon {
    display: inline-block;
    margin-left: 6px;
    color: var(--pm-primary);
    cursor: help;
    font-size: 16px;
    opacity: 0.7;
    transition: opacity 150ms ease;
  }

  #pdf-merger-tool #pdfForm label .help-icon:hover {
    opacity: 1;
  }
  
  /* Inputs and file inputs (compact vertical spacing) */
  #pdf-merger-tool #pdfForm input[type="text"],
  #pdf-merger-tool #pdfForm input[type="file"] {
    width: 100%;
    padding: 10px 12px;
    font-size: 20px;
    border: 2px solid rgba(154,152,158,0.22);
    border-radius: 8px;
    box-sizing: border-box;
    background: linear-gradient(180deg, #ffffff, #def7ff);
    color: var(--pm-text);
    margin-bottom: 6px; /* smaller gap between fields */
    text-align: center; /* preserves your existing visual */
    transition: border-color 200ms ease, box-shadow 200ms ease;
  }

  /* Valid state */
  #pdf-merger-tool #pdfForm input[type="text"].valid,
  #pdf-merger-tool #pdfForm input[type="file"].valid {
    border-color: #27ae60;
  }

  /* Invalid state */
  #pdf-merger-tool #pdfForm input[type="file"].invalid {
    border-color: #e74c3c;
  }

  /* Focus state (unchanged) */
  #pdf-merger-tool #pdfForm input[type="text"]:focus,
  #pdf-merger-tool #pdfForm input[type="file"]:focus {
    outline: none;
    border-color: var(--pm-primary);
    box-shadow: 0 6px 16px rgba(1,138,231,0.08);
  }

  /* File info display */
  #pdf-merger-tool .file-info {
    text-align: center;
    font-size: 14px;
    color: var(--pm-muted);
    min-height: 20px;
    margin-top: 4px;
  }

  #pdf-merger-tool .file-info .file-name {
    font-weight: 600;
    color: var(--pm-text);
  }

  #pdf-merger-tool .file-info .file-details {
    font-size: 13px;
    opacity: 0.8;
  }

  #pdf-merger-tool .file-info .checkmark {
    color: #27ae60;
    margin-right: 4px;
  }

  #pdf-merger-tool .file-info .error-icon {
    color: #e74c3c;
    margin-right: 4px;
  }

  /* Filename preview */
  #pdf-merger-tool .filename-preview {
    text-align: center;
    font-size: 14px;
    color: var(--pm-primary-2);
    font-weight: 600;
    min-height: 20px;
    margin-top: 4px;
    font-style: italic;
  }
  
  /* Button group (horizontal, centered) - you added this wrapper in HTML */
  #pdf-merger-tool #pdfForm .button-group {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-top: 6px;
  }
  
  /* Download button */
  #pdf-merger-tool #pdfForm button#downloadBtn {
    padding: 10px 18px;
    border-radius: 8px;
    border: none;
    font-weight: 700;
    cursor: pointer;
    background: linear-gradient(180deg, var(--pm-primary), var(--pm-primary-2));
    color: #fff;
    box-shadow: 0 2px 4px rgba(0,0,0,0.15);
    transition: transform 120ms ease, box-shadow 120ms ease;
  }

  #pdf-merger-tool #pdfForm button#downloadBtn .btn-icon {
    display: inline-block;
    margin-right: 4px;
  }

  /* Ready state pulse animation */
  #pdf-merger-tool #pdfForm button#downloadBtn.ready {
    animation: pulse 2s ease-in-out infinite;
  }

  @keyframes pulse {
    0%, 100% { box-shadow: 0 2px 4px rgba(0,0,0,0.15); }
    50% { box-shadow: 0 2px 12px rgba(1,138,231,0.5); }
  }

  /* hover / active micro-interaction left intact */
  #pdf-merger-tool #pdfForm button#downloadBtn:hover:not(:disabled) {
    transform: translateY(-2px);
  }
  #pdf-merger-tool #pdfForm button#downloadBtn:active:not(:disabled) {
    transform: translateY(0);
  }
  #pdf-merger-tool #pdfForm button#downloadBtn:disabled {
    opacity: 0.55;
    cursor: not-allowed;
    box-shadow: none;
  }
  
  /* Reset button: remove left margin (gap handles spacing) */
  #pdf-merger-tool #pdfForm input#resetBtn {
    padding: 10px 14px;
    border-radius: 8px;
    border: 1px solid rgba(154,152,158,0.14);
    background: #fbfdfe;
    color: var(--pm-muted);
    font-weight: 700;
    cursor: pointer;
  }
  
  /* Loading indicator */
  #pdf-merger-tool .loading-indicator {
    margin: 20px auto;
    text-align: center;
  }

  #pdf-merger-tool .spinner {
    border: 4px solid rgba(1,138,231,0.2);
    border-top: 4px solid var(--pm-primary);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    animation: spin 1s linear infinite;
    margin: 0 auto 12px auto;
  }

  @keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
  }

  #pdf-merger-tool #loadingStatus {
    font-size: 16px;
    color: var(--pm-muted);
    font-weight: 600;
  }

  /* Status text centered */
  #pdf-merger-tool #status {
    margin-top: 20px;
    font-size: 25px;
    text-align: center;
    font-weight: 800;
    color: var(--pm-primary-2);
  }
  
  /* Preview container */
  #pdf-merger-tool #previewContainer {
    margin-top: 20px;
    transition: opacity 300ms ease;
  }

  #pdf-merger-tool #previewContainer.collapsed #preview {
    display: none;
  }

  #pdf-merger-tool #previewHeader {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 12px 20px;
    background: var(--pm-primary);
    color: white;
    border-radius: 8px 8px 0 0;
    font-weight: 700;
    font-size: 18px;
  }

  #pdf-merger-tool .preview-toggle {
    background: none;
    border: none;
    color: white;
    font-size: 16px;
    cursor: pointer;
    padding: 4px 8px;
    transition: transform 200ms ease;
  }

  #pdf-merger-tool .preview-toggle:hover {
    transform: scale(1.2);
  }

  #pdf-merger-tool #previewContainer.collapsed .preview-toggle {
    transform: rotate(180deg);
  }

  /* Preview pane centered and responsive */
  #pdf-merger-tool #preview {
    margin-left: auto;
    margin-right: auto;
    width: 80%;
    height: 800px;
    border: 2px solid rgba(47,51,53,0.08);
    border-radius: 0 0 8px 8px;
    background: linear-gradient(180deg, #ffffff, #fbfdff);
    box-shadow: 0 5px 10px rgba(145,145,145,0.7);
    box-sizing: border-box;
    overflow: hidden;
  }

  /* Ensure embedded PDF fills preview */
  #pdf-merger-tool #preview embed,
  #pdf-merger-tool #preview iframe,
  #pdf-merger-tool #preview object {
    width: 100%;
    height: 100%;
    display: block;
    border: 0;
  }
  
  /* File input button appearance (modern and fallback) */
  #pdf-merger-tool input[type="file"]::file-selector-button {
    padding: 8px 10px;
    border-radius: 8px;
    border: 1px solid var(--pm-primary-2);
    background: #fff;
    cursor: pointer;
    font-weight: 700;
    color: var(--pm-primary-2);
    box-shadow: 0 2px 4px rgba(0,0,0,0.15);
  }
  #pdf-merger-tool input[type="file"]::-webkit-file-upload-button {
    padding: 8px 10px;
    border-radius: 8px;
    border: 1px solid var(--pm-primary-2);
    background: #fff;
    cursor: pointer;
    font-weight: 700;
    color: var(--pm-primary-2);
    box-shadow: 0 2px 4px rgba(0,0,0,0.15);
  }
  
  /* Toast notification */
  #pdf-merger-tool .toast {
    position: fixed;
    bottom: 30px;
    right: 30px;
    background: #27ae60;
    color: white;
    padding: 16px 24px;
    border-radius: 8px;
    box-shadow: 0 4px 12px rgba(0,0,0,0.3);
    font-weight: 600;
    font-size: 16px;
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 300ms ease, transform 300ms ease;
    pointer-events: none;
    z-index: 1000;
  }

  #pdf-merger-tool .toast.show {
    opacity: 1;
    transform: translateY(0);
  }

  #pdf-merger-tool .toast.error {
    background: #e74c3c;
  }

  /* Responsive adjustments */
  @media (max-width: 760px) {
    #pdf-merger-tool {
      padding: 20px;
    }
    #pdf-merger-tool h1 {
      font-size: 28px;
    }
    #pdf-merger-tool #pdfForm label {
      font-size: 16px;
    }
    #pdf-merger-tool #pdfForm input[type="text"],
    #pdf-merger-tool #pdfForm input[type="file"] {
      font-size: 16px;
      width: 100%;
      max-width: 100%;
    }
    /* Buttons stack on small screens */
    #pdf-merger-tool #pdfForm .button-group {
      flex-direction: column;
      width: 100%;
      gap: 8px;
    }
    #pdf-merger-tool #pdfForm .button-group > * {
      width: 100%;
    }
    /* Preview becomes full width and shorter */
    #pdf-merger-tool #preview {
      width: 100%;
      height: 420px;
    }
    /* Toast positioning on mobile */
    #pdf-merger-tool .toast {
      right: 15px;
      left: 15px;
      bottom: 15px;
    }
  }