Fixed flex design is too widht

Question

I've made a design with flex box. I've split my site in two parts. The left part has a width of 75% of the width of the window, the right side fill the rest.

The problem is now, when I place text into the right section, the text goes out of my screen. I've place a padding to the right side of that section but it must be 26.843.170 pixels (you read good) for to be good! To much of course... Note that the right side has a fixed position.

Now my question is, What I'm doing wrong? Here is my code:

$(".draw-area, .artist-info, .draw-en-info").css("height", parseInt($(window).height()) - parseInt($("fieldset").height()) + "px");

.option-list {
    width: 100%;
    height: 200px;
    overflow-y: auto;
    border: solid 1px #A9A9A9;
    margin: 10px 0;
}

.artist-info {
	background-color: lightgray;
    margin: 0;
    position: fixed;
    top: 50px;
    padding: 0 10px;
    width: 25%;
    /* padding-right: 26843170px; */
}

.option-item {
	display: flex;
    padding: 5px 10px;
    transition: background-color 0.5s;
    cursor: pointer;
}

.option-item:hover {
	background-color: #1DD75F;
}


.form-control {
	padding: 5px 5px;
}

#resultaatArtisten {
	display: none;
}

fieldset {
	background-color: white;
    position: fixed;
    width: 100%;
    margin: 0;
    border: 0;
    padding: 0;
    border-bottom: gray 2px solid;
}

fieldset > div {
	padding: 10px;
}

.draw-en-info {
	display: flex;
    flex-direction: row;
    flex-wrap: nowrap;
    position: absolute;
    top: 47.9px;
    width: 100%;
    z-index: -1;
}

#draw-area {
	width: 75%;
    margin: 0;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<main class="container">
	<fieldset>
		<div>
			<input type="text" class="form-control" placeholder="Zoek op artisten naam" id="zoekArtist" />
			<div class="option-list" id="resultaatArtisten"></div>
		<div>
	</fieldset>

	<div class="draw-en-info">
		<section id="draw-area"></section>
		<section class="artist-info">
			<p>Top nummers</p>
			<ul class="top-nummers">
              <li>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed non risus. Suspendisse lectus tortor, dignissim sit amet, adipiscing nec, ultricies sed, dolor. Cras elementum ultrices diam. Maecenas ligula massa, varius a, semper congue, euismod non, mi. Proin porttitor, orci nec nonummy molestie, enim est eleifend mi, non fermentum diam nisl sit amet erat. Duis semper. Duis arcu massa, scelerisque vitae, consequat in, pretium a, enim. Pellentesque congue. Ut in risus volutpat libero pharetra tempor. Cras vestibulum bibendum augue. Praesent egestas leo in pede. Praesent blandit odio eu enim. Pellentesque sed dui ut augue blandit sodales. Vestibulum ante ipsum primis in faucibus orci luctus et ultrices posuere cubilia Curae; Aliquam nibh. Mauris ac mauris sed pede pellentesque fermentum. Maecenas adipiscing ante non diam sodales hendrerit.Ut velit mauris, egestas sed, gravida nec, ornare ut, mi. Aenean ut orci vel massa suscipit pulvinar. Nulla sollicitudin. Fusce varius, ligula non tempus aliquam, </li>
          </ul>
		</section>
	</div>
</main>

Answer 1

I'm not entirely clear on what you are trying to do but flexbox can manage most of this.

If there are some requirements that you haven't mentioned you may need to ask a new question.

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  list-style-type: none;
}
.option-list {
  width: 100%;
  height: 200px;
  overflow-y: auto;
  border: solid 1px #A9A9A9;
  margin: 10px 0;
}
.draw-en-info {
  display: flex;
}
.draw-area {
  background: plum;
  flex: 1;
}
.artist-info {
  background-color: lightgray;
  padding: 0 10px;
  flex: 0 0 25%;
}
.option-item {
  display: flex;
  padding: 5px 10px;
  transition: background-color 0.5s;
  cursor: pointer;
}
.option-item:hover {
  background-color: #1DD75F;
}
.form-control {
  padding: 5px 5px;
}
#resultaatArtisten {
  display: none;
}
fieldset {
  background-color: white;
  //position: fixed;
  width: 100%;
  margin: 0;
  border: 0;
  padding: 0;
  border-bottom: gray 2px solid;
}
fieldset > div {
  padding: 10px;
}

<main class="container">
  <fieldset>
    <div>
      <input type="text" class="form-control" placeholder="Zoek op artisten naam" id="zoekArtist" />
      <div class="option-list" id="resultaatArtisten"></div>
      <div>
  </fieldset>

  <div class="draw-en-info">
    <section class="draw-area"></section>
    <section class="artist-info">
      <p>Top nummers</p>
      <ul class="top-nummers">
        <li>Lorem ipsum dolor sit amet, consectetur adipiscing elit. Sed non risus. Suspendisse lectus tortor, dignissim sit amet, adipiscing nec, ultricies sed, dolor. Cras elementum ultrices diam. Maecenas ligula massa, varius a, semper congue, euismod
          non, mi. Proin porttitor, orci nec nonummy molestie, enim est eleifend mi, non fermentum diam nisl sit amet erat. Duis semper. Duis arcu massa, scelerisque vitae, consequat in, pretium a, enim. Pellentesque congue. Ut in risus volutpat libero
          pharetra tempor. Cras vestibulum bibendum augue. Praesent egestas leo in pede. Praesent blandit odio eu enim. Pellentesque sed dui ut augue blandit sodales. Vestibulum ante ipsum primis in faucibus orci luctus et ultrices posuere cubilia Curae;
          Aliquam nibh. Mauris ac mauris sed pede pellentesque fermentum. Maecenas adipiscing ante non diam sodales hendrerit.Ut velit mauris, egestas sed, gravida nec, ornare ut, mi. Aenean ut orci vel massa suscipit pulvinar. Nulla sollicitudin. Fusce
          varius, ligula non tempus aliquam,</li>
      </ul>
    </section>
  </div>
</main>