Magento 2 – How to Override vendor/magento/magento2-base/lib/web/css/source/lib/_navigation.less

We have to just create mage folder inside our theme.

Magneto2/app/design/frontend/{Vendorname}/{themename}/web/mage

Keep gallery folder inside mage and remove var folder and apply command

php bin/magento setup:static-content:deploy

Its working fine.

You can override default less variables in your custom theme. In <magento-root>/lib/web/css/source/lib/variables/ you will find a number of LESS files.

In each of these you can find values assigned to variables for many of the common elements in Magento 2.

To override any of these variables, simply create a less file in your custom theme and update the variable like below.

app/design/frontend/{Namespace}/{theme}/web/css/source/_theme.less

//  Font families
@font-family__sans-serif: 'Helvetica Neue', Helvetica, Arial, sans-serif;
@font-family__serif: Georgia, 'Times New Roman', Times, serif;
@font-family__monospace: Menlo, Monaco, Consolas, 'Courier New', monospace;

Kindly refer to below links for more detail.

https://magento.stackexchange.com/a/110165/23943 https://magento.stackexchange.com/a/109808/23943