.main-section {
  background-image: url('../images/background.png');
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
  /* height: 100vh; /* oder auto / 100vh */
  /* position: relative; */
}

.main-title1 {
    font-size: 3vw;
    font-weight: bold;
    color: #666666;
    line-height: 1;
}

.main-title2 {
    font-size: 7vw;
    color: #DF7401;
    margin: 0px 0px 2vh 0px;
    line-height: 1;
    font-family: Impact, Charcoal, Helvetica Inserat, Bitstream Vera Sans Bold, Arial Black, Sans Serif;
}

.main-title3 {
    font-size: 4vw;
    color: #DF7401;
    margin: 0px 0px 2vh 0px;
    line-height: 0.7;
    margin-bottom: 20px;
    font-family: Impact, Charcoal, Helvetica Inserat, Bitstream Vera Sans Bold, Arial Black, Sans Serif;
}
main-image_plan {
    max-height: 50vh;
}

@media (max-width: 550px) {
    .main-title1 {
        font-size: 20px;
    }
    .main-title2 {
        font-size: 55px;
    }
    .main-title3 {
        font-size: 30px;
    }
    .main-image_plan {
        max-height: 45vh;
    }
}