Dear Stefan
@stefanstraeter
Lay Theme offers a Sub-menu feature:
https://laytheme.com/documentation/menus.html#submenus
You could use the feature and make the most of it's settings and then add CSS to make it fullscreen and slide etc.
A while ago a user mentioned this Plugin helping to create a fullscreen menu effect, but would be up to you π
https://wordpress.org/plugins/dc-full-screen-responsive-menu/
The Mouseover effect could be achieved with the Imagehover Addon for the images, but the "white line" through the text is an SVG that is applied. This would need to be custom coded.
Here you can see the :after selector being used on hover:
.works__section .works__inner .work .work__title a:after {
content: '';
position: absolute;
top: 0;
left: 0;
height: 100%;
width: 100%;
background: url(data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='786.406' height='62.855' viewBox='0 0 786.406 62.855'%3E%3Cpath d='M281.377,77.538c-4.364-.072-8.715.054-13.066.192-7.9.228-15.779.673-23.681.883-4.5.114-9,.216-13.5.276-4.376.048-8.752.03-13.153.006-7.927-.036-15.854-.325-23.768-.595-8.665-.288-17.279-.415-25.931-.319-4.2.048-8.39.084-12.59.1-3.751.006-7.5-.21-11.228-.391-4.013-.2-8-.295-12-.2-4.439.1-8.852.246-13.278.4-6.7.228-13.366.385-20.08.415-3.313.024-6.652-.1-9.977-.18-2.963-.072-5.939-.373-8.9-.583-2.526-.306-5.064-.625-7.577-.931-1.375-.174-2.738-.427-4.089-.649-2.1-.325-4.176-.625-6.289-.9-2.013-.264-4.051.252-4.639,1.472-.55,1.184.675,2.35,2.638,2.746,8.79,1.779,17.892,2.752,27.006,3.708,8.2.853,16.517,1.358,24.794,1.845,8.3.493,16.716.457,25.031.379,4.063-.048,8.127-.336,12.165-.547,3.926-.2,7.864-.252,11.815-.312,8.377-.126,16.817-.1,25.194.1,8.6.192,17.167.625,25.719,1.028q12.3.595,24.618,1.142c8.127.373,16.254.829,24.381,1.058,7.989.228,16,.415,23.993.337,4.089-.036,8.164-.114,12.266.072,1.813.078,3.638.138,5.451.282,2.113.18,4.226.354,6.327.523,7.227.739,14.428,1.6,21.68,2.271,7.8.727,15.654,1.34,23.481,2.037,8.477.913,16.942,1.923,25.394,2.908s16.979,1.713,25.506,2.422c8.34.7,16.779,1.039,25.156,1.412,4.076.18,8.152.355,12.215.547,3.838.192,7.639.5,11.465.835,3.651.379,7.314.745,10.965,1.1,1.938.192,3.838.33,5.777.445,1.775.108,3.563.264,5.339.318q11.365.343,22.706.625c14.278.337,28.544,1,42.7,2.271l-.388-.042,1.013.1.25.024-.163-.018q5.57.523,11.165.967c3.726.288,7.5.457,11.24.667q12.6.73,25.206,1.568c3.351.216,6.7.469,10.052.637,2.063.114,4.138.222,6.2.325,1.325.078,2.688.1,4.038.108l2.038.03c.775.018,1.575-.072,2.326-.108l3.076-.138c2.375-.108,4.726-.433,7.052-.733,1.838-.24,3.688-.553,5.576-.7,1.675-.132,3.363-.258,5.039-.385,2.188-.042,4.363-.078,6.551-.108,2.138-.042,4.3.066,6.439.12,4.014.1,8.027.306,12.041.469,4.3.186,8.614.325,12.928.349,4.276.018,8.527-.144,12.791-.289,8.127-.276,16.3-.288,24.456-.264,8.715.036,17.442.1,26.156.12,7.589.018,15.216-.084,22.781-.373,4.388-.162,8.777-.325,13.166-.559,1.638-.078,3.251-.222,4.9-.27,1.113-.036,2.213-.066,3.313-.1,1.263-.042,2.6.09,3.851.132,3.738.138,7.452.445,11.178.643,4.576.246,9.14.481,13.728.673,3.7.168,7.4.282,11.1.3,1.963-.006,3.888.03,5.826-.084,1.288-.084,2.588-.162,3.863-.234.813-.048,2.151-.09,2.626-.168,1.675-.27,3.376-.535,5.064-.8,3.063-.481,5.251-2.085,5.251-3.972a3.743,3.743,0,0,0-2.1-3.011,11.273,11.273,0,0,0-5.064-1.3,55.793,55.793,0,0,0-6.252-.4c-1.6.06-3.176.108-4.776.162-2.926.1-5.851.463-8.727.727-4.6.427-9.19.787-13.8,1.124l-8.327.294c-1.075.036-2.2-.048-3.263-.078q-2.307-.054-4.613-.1c-1.413-.126-2.838-.234-4.214-.451-2.213-.336-4.363-.637-6.576-.877a94.357,94.357,0,0,0-13.228-.186c-8.327.282-16.654.553-25.018.745-16.742.385-33.533-.018-50.3-.5q-9.6-.288-19.13.318c-6.014.391-12,.835-17.992,1.262-2.163.1-4.326.2-6.5.306-2.126.1-4.276.072-6.4.09-4.226.042-8.44-.216-12.641-.529-2.2-.168-4.4-.3-6.627-.439-.8-.048-1.651,0-2.463,0-1.05,0-2.138-.042-3.176.018-4.576.258-9.152.541-13.7.841-2.563.144-5.126.33-7.714.415-3.188.114-6.414.33-9.627.318q-5.176,0-10.352-.012c-1.488-.006-3.026-.162-4.5-.24-1.738-.09-3.488-.186-5.226-.276-2.088-.2-4.176-.4-6.264-.6-2.651-.258-5.3-.559-7.965-.727-5.526-.349-11.053-.607-16.591-.853q-7.745-.343-15.491-.787c-5.114-.294-10.19-.691-15.279-1.094-3.676-.361-7.339-.721-11.015-1.088-3.651-.367-7.264-.847-10.9-1.25-4.713-.529-9.415-1.022-14.166-1.442-3.913-.336-7.839-.613-11.753-.913-15.266-1.166-30.507-2.338-45.736-3.726-6.664-.637-13.341-1.262-19.992-1.953-7.7-.811-15.4-1.7-23.156-2.386-4.014-.366-8.014-.691-12.053-.943-3.563-.234-7.164-.342-10.74-.493-6.8-.289-13.541-.751-20.292-1.334-3.889-.451-7.764-.9-11.615-1.484-1.763-.27-3.538-.517-5.264-.835-2.175-.4-4.339-.823-6.514-1.2-1.313-.234-2.626-.469-3.939-.691-1.238-.216-2.488-.318-3.763-.433-1.3-.114-2.588-.228-3.9-.349-.513-.042-1.013-.06-1.525-.066s-1.025-.006-1.525-.012Zm73.23,15.708,1.325.12c-.438-.036-.888-.078-1.325-.12Zm206.35,8.96c.35.03.7.066,1.05.1l-1.05-.1Zm-18.842,3.942-.087-.006-.625-.054.712.06Z' transform='translate(-60.073 -45.524) rotate(-2)' fill='%23fff'/%3E%3C/svg%3E%0A) repeat-y center 15px;
opacity: 0;
transition: opacity .3s;
}
https://www.w3schools.com/cssref/sel_after.asp
The SVG is defined in the CSS as a background URL source:
https://www.w3schools.com/cssref/css3_pr_background.asp
You could therefore load the SVG into your Wordpress Media Library and call it from there (with it's URL).
Hope this helps Stefan & best wishes
Richard