html_css
1.playground {2position: relative;3border: 4px solid black;4height: 300px;5padding: 20px;6}
7
8.pos-box {9/*position: static;*/10/*position: absolute;*/11/*left top right bottom*/12/*!*top: 0;*!*/13/*!*left: 0;*!*/14/*bottom: 0;*/15/*right: 0;*/16position: fixed;17top: 0;18width: 50px;19height: 50px;20background: coral;21}
22
23.navbar {24position: fixed;25top: 0;26left: 0;27right: 0;28z-index: 2;29}
30#header {31margin-top: 60px;32}