Help required - User input for text search and delete remaining rows

Hello,

First post and very much a noob, so please go easy on me.

Initially my idea was to have the user enter a text search term via an input box and for this term to be highlighted blue and all other rows (not containing the search term) to be deleted/removed.

I have searched and searched for the answer but come up with no joy

So I have botched this crazy work around (See code below) using the interior cell colours to indicate which rows require deleting. This strange method does work, except for when the user enters a search term that is NOT contained within the data, all rows (because they are white!) are deleted. Can I somehow add msgbox to intervene if the search term isn't found? I've tried to do this but unfortunately with no success. Or failing that can someone come up with a bit of smart code to do exactly what I originally required - Search worksheet based on user input, highlight matches, delete all other rows that do not contain a match.

Hopefully you wonderful people can help.

Sub DeleteRows()

    Dim SrchStr, Prompt, Title As String
    Dim rCell As Range
    Dim x As Long
    Dim y As Long
    Dim rngTempb As Range
    Dim LastRow As Long
    Dim i As Long
     
    Application.ScreenUpdating = False
     
    
startSearch1:
    Title = "Please enter Search Term?"
    SrchStr = Application.InputBox(Prompt, Title, "")
    
    If SrchStr = False Then Exit Sub
'Force valid entry
     If SrchStr = "" Then
       If MsgBox("The Search Field Can Not Be Left Blank" _
       & vbLf & vbLf & "Do You Want To Try Again?", vbYesNo + vbQuestion, "...") = _
                        vbNo Then Exit Sub
          GoTo startSearch1
     End If
    
    Set rngTempb = Cells.Find("*", SearchOrder:=xlByRows, SearchDirection:=xlPrevious)
If Not rngTempb Is Nothing Then
    Range(Cells(1, 1), rngTempb).Select
End If
    
    y = Len(SrchStr)
 For Each rCell In Selection
     x = 1
     Do
       x = InStr(x, UCase(rCell.Value), UCase(SrchStr))
       If x > 0 Then
           rCell.Characters(x, y).Font.Color = vbBlue
           rCell.Characters(x, y).Font.Bold = True
           rCell.EntireRow.Interior.Color = RGB(255, 255, 254)
           x = x + 1
            End If
     Loop Until x = 0
 Next rCell
    
    LastRow = ActiveSheet.UsedRange.Rows.Count + ActiveSheet.UsedRange.Rows(1).Row - 1
    
    For i = LastRow To 2 Step -1
        If Cells(i, "A").Interior.Color = RGB(255, 255, 255) Or Cells(i, "A").Interior.Color = RGB(218, 150, 148) Then
            Rows(i).Delete
        End If
    Next i
    
    
  Application.ScreenUpdating = True
       
End Sub