I am a full-stack web developer with 4 years of professional experience. I am well-versed in HTML, CSS, Javascript, Bootstrap, Responsive web design, AngularJS etc. on the front-end and PHP, MySQL, NodeJS, MongoDB and have experience across a wide range of complex front-end web applications developed for major sports companies around the world.
I have browsed through the Styleseat website which you have mentioned and I believe I will be able to deliver a similar neat-looking, fluid application to you. I will make use of Bootstrap to make an elegant responsive solution and of HTML5, CSS3, Javascript/jQuery wherever needed. If you want some back-end as well like APIs, database etc, I will be able to develop that as well, but in that case, my price will increase and the number of days to complete the project will increase depending on the scope of work.
I will ensure the application is thoroughly tested for its functionality and also for its responsiveness across different screen sizes.