grunt lint

Running "csslint:all" (csslint) task
Linting public/modules/challenges/css/challenges.css ...ERROR
[L33:C2]
Background image '../../../img/icons/doc.png' was used multiple times, first declared at line 29, col 2. Every background-image should be unique. Use a common class for e.g. sprites. (duplicate-background-images)
Linting public/modules/core/css/core.css ...ERROR
[L1:C1]
Rule is empty. Rules without any properties specified should be removed. (empty-rules)
Linting public/modules/core/css/custom.css ...ERROR
[L65:C3]
The property -moz-transition is compatible with -webkit-transition and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L65:C3]
The property -o-transition is compatible with -webkit-transition and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L69:C1]
Outlines shouldn't be hidden unless other visual changes are made. Use of outline: none or outline: 0 should be limited to :focus rules. (outline-none)
[L225:C1]
Don't use IDs in selectors. Selectors should not contain IDs. (ids)
[L230:C3]
The property -moz-box-shadow is compatible with -webkit-box-shadow and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L233:C1]
Don't use IDs in selectors. Selectors should not contain IDs. (ids)
[L263:C3]
The property -moz-box-shadow is compatible with -webkit-box-shadow and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L358:C3]
The property -moz-box-shadow is compatible with -webkit-box-shadow and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L366:C3]
The property -moz-box-shadow is compatible with -webkit-box-shadow and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L373:C3]
The property -moz-box-shadow is compatible with -webkit-box-shadow and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L380:C3]
The property -moz-box-shadow is compatible with -webkit-box-shadow and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L387:C3]
The property -moz-box-shadow is compatible with -webkit-box-shadow and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L439:C3]
float can't be used with display: inline-block. Certain properties shouldn't be used with certain display property values. (display-property-grouping)
[L622:C3]
The property -o-transition is compatible with -webkit-transition and -moz-transition and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L650:C3]
The property -o-transition is compatible with -webkit-transition and -moz-transition and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L658:C3]
The property -o-transition is compatible with -webkit-transition and -moz-transition and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L712:C10]
Values of 0 shouldn't have units specified. You don't need to specify units when a value is 0. (zero-units)
[L717:C3]
The property -o-transform is compatible with -webkit-transform and -moz-transform and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L717:C3]
The property -ms-transform is compatible with -webkit-transform and -moz-transform and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L720:C3]
The property -o-transition is compatible with -webkit-transition and -moz-transition and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L752:C3]
The property -o-transition is compatible with -webkit-transition and -moz-transition and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L761:C1]
Outlines should only be modified using :focus. Use of outline: none or outline: 0 should be limited to :focus rules. (outline-none)
[L838:C15]
>> Expected a hex color but found '#white' at line 838, col 15. This rule looks for recoverable syntax errors. (errors)
[L853:C3]
The property -ms-transform is compatible with -webkit-transform and -moz-transform and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L853:C3]
The property -o-transform is compatible with -webkit-transform and -moz-transform and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L889:C3]
The property -o-transition is compatible with -moz-transition and -webkit-transition and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L902:C3]
The property -o-transition is compatible with -moz-transition and -webkit-transition and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L947:C3]
The property -moz-box-shadow is compatible with -webkit-box-shadow and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L1059:C1]
Don't use IDs in selectors. Selectors should not contain IDs. (ids)
[L1062:C1]
Don't use IDs in selectors. Selectors should not contain IDs. (ids)
[L1067:C1]
Don't use IDs in selectors. Selectors should not contain IDs. (ids)
[L1068:C1]
Don't use IDs in selectors. Selectors should not contain IDs. (ids)
[L1072:C1]
Don't use IDs in selectors. Selectors should not contain IDs. (ids)
[L1077:C1]
Don't use IDs in selectors. Selectors should not contain IDs. (ids)
[L1081:C1]
Don't use IDs in selectors. Selectors should not contain IDs. (ids)
[L1084:C1]
Don't use IDs in selectors. Selectors should not contain IDs. (ids)
[L1088:C1]
Don't use IDs in selectors. Selectors should not contain IDs. (ids)
[L1091:C1]
Don't use IDs in selectors. Selectors should not contain IDs. (ids)
[L1094:C1]
Don't use IDs in selectors. Selectors should not contain IDs. (ids)
[L1100:C1]
Don't use IDs in selectors. Selectors should not contain IDs. (ids)
[L1103:C1]
Don't use IDs in selectors. Selectors should not contain IDs. (ids)
[L1141:C3]
The property -moz-box-orient is compatible with -webkit-box-orient and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L1141:C3]
The property -ms-box-orient is compatible with -webkit-box-orient and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L1159:C3]
margin can't be used with display: table-cell. Certain properties shouldn't be used with certain display property values. (display-property-grouping)
[L1179:C3]
The property -moz-box-shadow is compatible with -webkit-box-shadow and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L1240:C1]
Don't use IDs in selectors. Selectors should not contain IDs. (ids)
[L1241:C1]
Don't use IDs in selectors. Selectors should not contain IDs. (ids)
[L1274:C3]
The property -moz-transition is compatible with -webkit-transition and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L1274:C3]
The property -o-transition is compatible with -webkit-transition and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L1279:C31]
Values of 0 shouldn't have units specified. You don't need to specify units when a value is 0. (zero-units)
[L1281:C3]
Duplicate property '-webkit-transition' found. Duplicate properties must appear one after the other. (duplicate-properties)
[L1282:C3]
Duplicate property 'transition' found. Duplicate properties must appear one after the other. (duplicate-properties)
[L1304:C3]
Fallback background-color (hex or RGB) should precede RGBA background-color. For older browsers that don't support RGBA, HSL, or HSLA, provide a fallback color. (fallback-colors)
[L1309:C3]
The property -o-transition is compatible with -webkit-transition and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L1309:C3]
The property -moz-transition is compatible with -webkit-transition and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L1324:C3]
The property -moz-transition is compatible with -webkit-transition and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L1324:C3]
The property -o-transition is compatible with -webkit-transition and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L1341:C3]
Fallback background-color (hex or RGB) should precede RGBA background-color. For older browsers that don't support RGBA, HSL, or HSLA, provide a fallback color. (fallback-colors)
[L1347:C3]
The property -moz-transition is compatible with -webkit-transition and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L1347:C3]
The property -o-transition is compatible with -webkit-transition and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L1363:C3]
The property -moz-transition is compatible with -webkit-transition and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L1363:C3]
The property -o-transition is compatible with -webkit-transition and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L1488:C3]
The property -o-transition is compatible with -webkit-transition and -moz-transition and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L1516:C3]
The property -moz-box-shadow is compatible with -webkit-box-shadow and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L1583:C3]
The property -moz-transform is compatible with -webkit-transform and -ms-transform and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L1583:C3]
The property -o-transform is compatible with -webkit-transform and -ms-transform and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L1590:C3]
The property -moz-animation is compatible with -webkit-animation and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L1597:C3]
The property -moz-transition is compatible with -webkit-transition and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L1597:C3]
The property -o-transition is compatible with -webkit-transition and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L1599:C3]
The property -moz-animation is compatible with -webkit-animation and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L1605:C3]
The property -o-transition is compatible with -webkit-transition and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L1605:C3]
The property -moz-transition is compatible with -webkit-transition and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L1608:C1]
Don't use IDs in selectors. Selectors should not contain IDs. (ids)
[L1624:C1]
Don't use IDs in selectors. Selectors should not contain IDs. (ids)
[L1626:C3]
The property -o-transition is compatible with -webkit-transition and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L1626:C3]
The property -moz-transition is compatible with -webkit-transition and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L1632:C5]
Missing standard property 'transform' to go along with '-webkit-transform'. When using a vendor-prefixed property, make sure to include the standard one. (vendor-prefix)
[L1635:C5]
Missing standard property 'transform' to go along with '-webkit-transform'. When using a vendor-prefixed property, make sure to include the standard one. (vendor-prefix)
[L1638:C5]
Missing standard property 'transform' to go along with '-webkit-transform'. When using a vendor-prefixed property, make sure to include the standard one. (vendor-prefix)
[L1641:C5]
Missing standard property 'transform' to go along with '-webkit-transform'. When using a vendor-prefixed property, make sure to include the standard one. (vendor-prefix)
[L1644:C5]
Missing standard property 'transform' to go along with '-webkit-transform'. When using a vendor-prefixed property, make sure to include the standard one. (vendor-prefix)
[L1692:C3]
The property -moz-transition is compatible with -webkit-transition and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L1692:C3]
The property -o-transition is compatible with -webkit-transition and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L1706:C3]
The property -moz-box-shadow is compatible with -webkit-box-shadow and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L1708:C3]
The property -o-transition is compatible with -webkit-transition and -moz-transition and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L1717:C3]
The property -o-transition is compatible with -webkit-transition and -moz-transition and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L1723:C3]
The property -moz-box-shadow is compatible with -webkit-box-shadow and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L1725:C3]
Fallback color (hex or RGB) should precede RGBA color. For older browsers that don't support RGBA, HSL, or HSLA, provide a fallback color. (fallback-colors)
[L1735:C3]
Fallback border (hex or RGB) should precede RGBA border. For older browsers that don't support RGBA, HSL, or HSLA, provide a fallback color. (fallback-colors)
[L1743:C3]
Fallback background (hex or RGB) should precede RGBA background. For older browsers that don't support RGBA, HSL, or HSLA, provide a fallback color. (fallback-colors)
[L1745:C1]
Outlines should only be modified using :focus. Use of outline: none or outline: 0 should be limited to :focus rules. (outline-none)
[L1756:C3]
The property -o-transition is compatible with -webkit-transition and -moz-transition and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L1824:C3]
The property -o-transition is compatible with -webkit-transition and -moz-transition and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L2094:C3]
Fallback color (hex or RGB) should precede RGBA color. For older browsers that don't support RGBA, HSL, or HSLA, provide a fallback color. (fallback-colors)
[L2109:C3]
The property -o-transition is compatible with -webkit-transition and -moz-transition and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L2154:C3]
The property -moz-box-shadow is compatible with -webkit-box-shadow and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L2389:C2]
Fallback background (hex or RGB) should precede RGBA background. For older browsers that don't support RGBA, HSL, or HSLA, provide a fallback color. (fallback-colors)
[L2639:C1]
Missing vendor-prefixed CSS gradients for Old Webkit (Safari 4+, Chrome). When using a vendor-prefixed gradient, make sure to use them all. (gradients)
[L2644:C2]
Duplicate property 'background' found. Duplicate properties must appear one after the other. (duplicate-properties)
[L2649:C2]
Standard property 'box-shadow' should come after vendor-prefixed property '-webkit-box-shadow'. When using a vendor-prefixed property, make sure to include the standard one. (vendor-prefix)
[L2650:C2]
Standard property 'box-shadow' should come after vendor-prefixed property '-moz-box-shadow'. When using a vendor-prefixed property, make sure to include the standard one. (vendor-prefix)
[L2701:C1]
Rule is empty. Rules without any properties specified should be removed. (empty-rules)
[L2720:C1]
Rule is empty. Rules without any properties specified should be removed. (empty-rules)
[L3021:C38]
Values of 0 shouldn't have units specified. You don't need to specify units when a value is 0. (zero-units)
[L3022:C37]
Values of 0 shouldn't have units specified. You don't need to specify units when a value is 0. (zero-units)
[L3024:C34]
Values of 0 shouldn't have units specified. You don't need to specify units when a value is 0. (zero-units)
[L3025:C33]
Values of 0 shouldn't have units specified. You don't need to specify units when a value is 0. (zero-units)
[L3027:C30]
Values of 0 shouldn't have units specified. You don't need to specify units when a value is 0. (zero-units)
[L3028:C29]
Values of 0 shouldn't have units specified. You don't need to specify units when a value is 0. (zero-units)
[L3031:C2]
Duplicate property 'padding' found. Duplicate properties must appear one after the other. (duplicate-properties)
[L3467:C3]
float can't be used with display: table-row. Certain properties shouldn't be used with certain display property values. (display-property-grouping)
[L3702:C1]
Rule is empty. Rules without any properties specified should be removed. (empty-rules)
[L3831:C1]
Missing vendor-prefixed CSS gradients for Webkit (Safari 5+, Chrome), Opera 11.1+. When using a vendor-prefixed gradient, make sure to use them all. (gradients)
[L3873:C3]
Duplicate property 'font-weight' found. Duplicate properties must appear one after the other. (duplicate-properties)
[L4391:C3]
Don't use IDs in selectors. Selectors should not contain IDs. (ids)
[L4455:C3]
Don't use IDs in selectors. Selectors should not contain IDs. (ids)
[L4561:C3]
Rule is empty. Rules without any properties specified should be removed. (empty-rules)
[L4587:C3]
Rule is empty. Rules without any properties specified should be removed. (empty-rules)
[L4604:C5]
The property -moz-transform is compatible with -ms-transform and -webkit-transform and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L4604:C5]
The property -o-transform is compatible with -ms-transform and -webkit-transform and should be included as well. Include all compatible vendor prefixes to reach a wider range of users. (compatible-vendor-prefixes)
[L4604:C5]
Standard property 'transform' should come after vendor-prefixed property '-ms-transform'. When using a vendor-prefixed property, make sure to include the standard one. (vendor-prefix)
[L4605:C5]
Standard property 'transform' should come after vendor-prefixed property '-webkit-transform'. When using a vendor-prefixed property, make sure to include the standard one. (vendor-prefix)
[L4691:C4]
Don't use IDs in selectors. Selectors should not contain IDs. (ids)
[L4795:C10]
Values of 0 shouldn't have units specified. You don't need to specify units when a value is 0. (zero-units)
Warning: Task "csslint:all" failed. Used --force, continuing.