*,
::before,
::after{
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

body{
    background: #333;
    font-family: Arial, Helvetica, sans-serif;
}

.container{
    width: 400px;
    height: 400px;
    margin: 100px auto;
}

.c1 {
    background: salmon;
}
.c2{
    background: lightblue;
}
.c3{
    background: lightgreen;
}
.c4{
    background: khaki;
}
.c5{
    background: sandybrown;
}
.c6{
    background: slateblue;
}

.c1{
    display: flex;
    justify-content: center;
    align-items: center;
}
.c1 h1{
    
}