*{
margin: 0;
padding: 0;
box-sizing: border-box;
}
body{
width: 100vw;
height: 100vh;
font-family: 'Open Sans', sans-serif;
}
.pierwszy {
width: 12%;
height: 35%;
background-repeat: no-repeat;
float: left;
padding: 5px;
background-image: url(img/only2.png);
}
.drugi{
width: 88%;
height: 35%;
background-color: #145A32;
float: right;
display: block;
}
.clear{
content: "";
clear: both;
}
.bar {
width: 100%;
height: 72px;
background-color: #50bb00;
}
.tresc{
width: 100%;
height: 100%;
background-color: rgba(60, 60, 62, 0.85);
}
.tresc p{
padding: 30px;
font-size: 20px;
color: white;
}
.tresc img{
width: 200px;
height: 135px;
}
.button{
border-top-right-radius: 10px;
border-top-left-radius: 10px;
border-bottom-right-radius: 10px;
border-bottom-left-radius: 10px;
width: 125px;
height: 50px;
background-color: #bb00b0;
margin: 10px;
padding: 13px;
float: left;
position: relative;
left: 25%;
color: white;
}
.button:hover{
width: 125px;
height: 50px;
background-color: #a10097;
margin: 10px;
padding: 13px;
float: left;
position: relative;
left: 25%;
color: white;
}

.stopka{
width: 100%;
height: 45px;
padding: 13px;
background-color: rgba(0, 175, 0, 0.8);

}
.stopka p{
float: right;
color: white;
}
.textarea{
background-color: gray;
}<br>