How to design the navigation at the bottom of a page?

recently encountered a need to make a page with bottom navigation, the content on the page requires a screen display (try not to have scrolling), but also compatible with 1366 768,1440 900,1920 em > 1080 these screens, can it be realized by code?
first of all, the navigation bar at the bottom only needs to position the navigation bar at the top at the bottom of the page. (the navigation bar can be found in the Rookie League * all kinds)

then, if you are compatible with screens 1366 768,1440 900,1920 em > 1080, you can generally write a media query with three nodes.
the specific code for media query is

.
        @media screen and (min-width: 1000px) and (max-width:1367px){/*1366*768*/
            .body{
                background: -sharp000;
            }/**/
        }
        @media screen and (min-width: 1367px) and (max-width:1441px){/*1440*900*/
            .body{
                background: -sharp000;
            }/**/
        }
        @media screen and (min-width: 1441px) and (max-width:1920px){/*1920*1080*/
            .body{
                background: -sharp000;
            }/**/
        }
Apr.10,2021

position:fixed


this is a problem where div is fixed at the bottom

this key css knowledge point lies in position:fixed

https://blog.csdn.net/lanmanc.
https://www.cnblogs.com/Rinpe.


    position:fixed;*
    1366768 14409001920*1080
    :
    @media screen and (min-width: 1000px) and (max-width:1367px){/*1366*768*/
        .body{
            background: -sharp000;
        }/**/
    }
    @media screen and (min-width: 1367px) and (max-width:1441px){/*1440*900*/
        .body{
            background: -sharp000;
        }/**/
    }
    @media screen and (min-width: 1441px) and (max-width:1920px){/*1920*1080*/
        .body{
            background: -sharp000;
        }/**/
    }

[CSS] footer fixed at the bottom

        body {
            display: flex;
            flex-direction: column;
            min-height: 100vh;
            margin: 0;
        }
        main {
            flex: 1;
        }
        header { text-align: center; height: 3em; }
        main, footer {
            display: block;
            padding: .5em calc(50% - 400px);
        }
        footer {
            background: linear-gradient(-sharp222, -sharp444);
            color: white;
        }
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