Add hidding style for close button in modal

This style allows to hide close button in the modals

Fix NPM & GitHub pages deployment

• Don't clean up build result #653
• Revert changes on deployment #654

Add css fix for forward preview modifier

Fix picto position in preview-forward modifier.

Add css fix for inline preview modifier

Fix image height in preview-inline modifier.

Add preview modifiers & Downgrade KSS version

• Adding of 3 new modifiers for preview : preview-forward, preview-reduced, preview-inline.

• Downgrade the kss version, to solve the problem with the svg icons that no longer appear in Colette.

Avatar border thinner

• Avatar border is now thinner: 1px

Dark mode implementation

Breaking changes

Dark mode implementation
Declaration of css variables
Split colors helpers

New features

Fill-color helper
Flexbox helpers
Modifier fix height for modals

Fix

Move animations out of blocks
Fix icon fallback color for IE
Replace the old arrows pictos
Clean SVG
Pager alignment
Reduce line height for teaser-headline

Add FLX helpers

We added FLX helpers to flexbox helpers for manage flex: 0; flex: 1; flex: 2; flex: 3;

Add modal helper

New helper for a modal with a fixed height at 70vh and an inner scroll

Reduce line-height of .teaser-headline

• Reduce line-height of .teaser-headline