body {
    margin: 0;
}

#container_container {
    width: 1100px;
    height: 600px;
    margin: auto;
}

.container {
    border: 5px black solid;
    margin: 20px;
    width: 500px;
    height: 500px;
    background-color: white;
    float: left;
}

.block {
    border: 5px black solid;
    box-sizing: border-box;
    float: left;
}

#block_1 {
    background-color: red;
    height: 30%;
    width: 30%;
}

#block_2 {
    background-color: white;
    width: 55%;
    height: 15%;
}

#block_3 {
    background-color: yellow;
    width: 40%;
    height: 15%;
}

#block_4 {
    background-color: blue;
    height: 55%;
    width: 15%;
}

#block_5 {
    background-color: yellow;
    height: 15%;
    width: 15%;
    margin-top: -15%;
}

#block_6 {
    background-color: white;
    height: 70%;
    width: 15%;
}

#block_7 {
    background-color: blue;
    height: 15%;
    width: 30%;
    margin-top: -55%;
}

#block_8 {
    background-color: yellow;
    height: 55%;
    width: 15%;
    margin-top: -40%;
}

#block_9 {
    background-color: red;
    height: 40%;
    width: 40%;
    margin-top: -55%;
    margin-left: 15%;
}

#block_10 {
    background-color: white;
    height: 40%;
    width: 15%;
    margin-top: -40%;
}

#block_11 {
    background-color: blue;
    height: 15%;
    width: 85%;
}

#block_12 {
    background-color: yellow;
    height: 15%;
    width: 40%;
    margin-top: -30%;
    margin-left: 30%;
}

#block_13 {
    background-color: red;
    height: 15%;
    width: 15%;
    margin-top: -30%;
    margin-left: 70%;
}
.backgroundsize{
    background-repeat: no-repeat;
    background-position: center;
    background-size: 100% 100%;
}
#block_1_img {
    background-image: url("../photos/huiswerk_week4/kat1.jpg");
    height: 30%;
    width: 30%;
}

#block_2_img {
    background-image: url("../photos/huiswerk_week4/kat2.jpg");
    width: 55%;
    height: 15%;
}

#block_3_img {
    background-image: url("../photos/huiswerk_week4/kat3.jpg");
    width: 40%;
    height: 15%;
}

#block_4_img {
    background-image: url("../photos/huiswerk_week4/kat4.jpg");
    height: 55%;
    width: 15%;
}

#block_5_img {
    background-image: url("../photos/huiswerk_week4/kat3.jpg");
    height: 15%;
    width: 15%;
    margin-top: -15%;
}

#block_6_img {
    background-image: url("../photos/huiswerk_week4/kat2.jpg");
    height: 70%;
    width: 15%;
}

#block_7_img {
    background-image: url("../photos/huiswerk_week4/kat4.jpg");
    height: 15%;
    width: 30%;
    margin-top: -55%;
}

#block_8_img {
    background-image: url("../photos/huiswerk_week4/kat3.jpg");
    height: 55%;
    width: 15%;
    margin-top: -40%;
}

#block_9_img {
    background-image: url("../photos/huiswerk_week4/kat1.jpg");
    height: 40%;
    width: 40%;
    margin-top: -55%;
    margin-left: 15%;
}

#block_10_img {
    background-image: url("../photos/huiswerk_week4/kat2.jpg");
    height: 40%;
    width: 15%;
    margin-top: -40%;
}

#block_11_img {
    background-image: url("../photos/huiswerk_week4/kat4.jpg");
    height: 15%;
    width: 85%;
}

#block_12_img {
    background-image: url("../photos/huiswerk_week4/kat3.jpg");
    height: 15%;
    width: 40%;
    margin-top: -30%;
    margin-left: 30%;
}

#block_13_img {
    background-image: url("../photos/huiswerk_week4/kat1.jpg");
    height: 15%;
    width: 15%;
    margin-top: -30%;
    margin-left: 70%;
}