Mily Jozef,

ako sa mas? Ja sa mam dobre, a ty?  'thin' ='medium' = 'thick'. 

Furthermore, these widths must be constant throughout a document. 

'border-top-width', 'border-right-width', 'border-bottom-width',
'border-left-width' Value:   border-width | inherit  Initial:   medium  Applies
to:   all elements  Inherited:   no  Percentages:   N/A  Media:   visual
Computed value:   absolute length; '0' if the border style is 'none' or
'hidden'  

These properties set the width of the top, right, bottom, and left border of a
box. 

'border-width' Value:   border-width{1,4} | inherit  Initial:   see individual
properties  Applies to:   all elements  Inherited:   no  Percentages:   N/A
Media:   visual  Computed value:   see individual properties  

This property is a shorthand property for setting 'border-top-width',
'border-right-width', 'border-bottom-width', and 'border-left-width' at the
same place in the style sheet. 

If there is only one value, it applies to all sides. If there are two values,
the top and bottom borders are set to the first value and the right and left
are set to the second. If there are three values, the top is set to the first
value, the left and right are set to the second, and the bottom is set to the
third. If there are four values, they apply to the top, right, bottom, and
left, respectively.