body {
    margin: 0;
}
* {
    font-family: Tahoma;
}
header {
    display: flex;
}
#baner_1,
#baner_2,
#baner_3 {
    background-color: #7DA453;
    color: white;
    height: 120px;
} 
#baner_1,
#baner_2 {
    width: 40%;
}
#baner_3 {
    width: 20%;
}
main {
    display: flex;
    flex-wrap: wrap;
}
.dzien {
    background-color: #AED581;
    width: 200px;
    height: 100px;
    margin: 7px;
    border: 1px solid #7DA453;
}
.dzien:hover {
    background-color: #7DA453;
    color: white;
}
footer {
    background-color: #7DA453;
    color: white;
    padding: 5px;
}
h5 {
    text-align: center;
}
form {
    padding-top: 50px;
}