/* RESET STYLES & HELPER CLASSES
–––––––––––––––––––––––––––––––––––––––––––––––––– */
:root {
  /*--level-1: #8dccad;
  --level-2: #f5cc7f;
  --level-3: #7b9fe0;
  --level-4: #f27c8d;*/
  --black: black;
}

a:link, a:visited, a:active, a:hover {
    text-decoration:none;
}
* {
  padding: 0;
  margin: 0;
  box-sizing: border-box;
}

ol {
  list-style: none;
}

body {
  margin: 50px 0 100px;
  text-align: center;
  font: 20px/1.5 "Inter", sans-serif;
}
/*
h1,
h2,
h3,
h4 {
  font-size: inherit;
}
*/
.container {
  max-width: 800px;
  padding: 0 10px;
  margin: 0 auto;
  display: grid;
  align-items: center;
  justify-content: center;
  grid-column-gap: 20px;
  grid-template-columns: auto auto;
}

.rectangle {
  position: relative;
  width: 200px;
  height: 200px;
  background-color: #fff;
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.15);
}


/* LEVEL-1 STYLES
–––––––––––––––––––––––––––––––––––––––––––––––––– */
.level-1 {
  background: var(--level-1);
}

.level-1::before {
  content: "";
  position: absolute;
  top: 50%;
  left: 100%;
  transform: translateY(-50%);
  width: 20px;
  height: 2px;
  background: var(--black);
}


/* LEVEL-2 STYLES
–––––––––––––––––––––––––––––––––––––––––––––––––– */
.level-2-wrapper {
  position: relative;
  padding-left: 20px;
 /* border-left: 2px solid var(--black);*/
}

.level-2-wrapper::before {
  display: none;
  content: "";
  position: absolute;
  top: -20px;
  left: 10px;
  width: 2px;
  height: calc(100% + 40px);
  background: var(--black);
}

.level-2-wrapper::after {
  display: none;
  content: "";
  position: absolute;
  left: 10px;
  bottom: -20px;
  width: calc(100% - 10px);
  height: 2px;
  background: var(--black);
}

.level-2-wrapper > li {
  position: relative;
  display: grid;
  align-items: flex-start;
  grid-column-gap: 20px;
  grid-template-columns: auto auto;
}

.level-2-wrapper > li:last-child {
  margin-top: 100px;
  align-items: flex-end;
}

.level-2 {
  /*background: var(--level-2);*/
}

.level-2::before {
  content: "";
  position: absolute;
  top: 50%;
  right: 100%;
  transform: translateY(-50%);
  width: 20px;
  /*/height: 2px;*/
  background: var(--black);
}

.level-2::after {
  content: "";
  position: absolute;
  top: 50%;
  left: 100%;
  transform: translateY(-50%);
  width: 20px;
  height: 2px;
  background: var(--black);
}


/* LEVEL-3 STYLES
–––––––––––––––––––––––––––––––––––––––––––––––––– */
.level-3-wrapper {
  position: relative;
  top: 34px;
  padding-left: 20px;
  border-left: 2px solid var(--black);
}

.level-3-wrapper::before {
  display: none;
  content: "";
  position: absolute;
  top: 0;
  left: 10px;
  width: 2px;
  height: 100%;
  background: var(--black);
}

.level-3-wrapper::after {
  display: none;
  content: "";
  position: absolute;
  left: 10px;
  bottom: 0px;
  width: calc(100% - 10px);
  height: 2px;
  background: var(--black);
}

.level-3-wrapper > li {
  display: grid;
  grid-column-gap: 20px;
  grid-template-columns: auto auto;
}

.level-3-wrapper > li:last-child {
  margin-top: 80px;
}

.level-2-wrapper > li:last-child .level-3-wrapper {
  top: -34px;
}

.level-3 {
  /*background: var(--level-3);*/
}

.level-3::before {
  content: "";
  position: absolute;
  top: 50%;
  right: 100%;
  transform: translateY(-50%);
  width: 20px;
  height: 2px;
  background: var(--black);
}

.level-3::after {
  content: "";
  position: absolute;
  top: 50%;
  left: 100%;
  transform: translateY(-50%);
  width: 20px;
  height: 2px;
  background: var(--black);
}


/* LEVEL-4 STYLES
–––––––––––––––––––––––––––––––––––––––––––––––––– */
.level-4-wrapper {
  position: relative;
  top: 34px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  grid-column-gap: 20px;
  padding-left: 20px;
}

.level-4-wrapper::before {
  content: "";
  position: absolute;
  top: 0;
  left: 0;
  width: 2px;
  height: 50%;
  background: var(--black);
}

.level-3-wrapper > li:last-child .level-4-wrapper {
  top: -34px;
}

.level-3-wrapper > li:last-child .level-4-wrapper::before {
  top: auto;
  bottom: 0;
}

.level-4 {
  /*background: var(--level-4);*/
}

.level-4::before {
  content: "";
  position: absolute;
  top: 50%;
  right: 100%;
  transform: translateY(-50%);
  width: 20px;
  height: 2px;
  background: var(--black);
}


/* MQ STYLES
–––––––––––––––––––––––––––––––––––––––––––––––––– */
@media screen and (max-width: 1650px) {
  .rectangle {
    width: 150px;
  }
}

@media screen and (max-width: 1300px) {
  body {
    font-size: 16px;
  }
  
  h1,
  h2,
  h3,
  h4 {
    font-size: revert;
  }

  .rectangle {
    padding: 20px 10px;
    width: auto;
  }

  .container {
    display: block;
  }

  .level-1 {
    margin-bottom: 20px;
  }

  .level-1::before,
  .level-2::after,
  .level-3::after {
    display: none;
  }

  .level-2-wrapper::before,
  .level-2-wrapper::after,
  .level-3-wrapper::before,
  .level-3-wrapper::after,
  .level-2-wrapper > li,
  .level-3-wrapper > li {
    display: block;
  }

  .level-2-wrapper {
    padding-left: 30px;
    border-left: none;
  }

  .level-2-wrapper > li:last-child {
    margin-top: 50px;
  }

  .level-2-wrapper > li:last-child .level-3-wrapper,
  .level-3-wrapper > li:last-child .level-4-wrapper,
  .level-3-wrapper,
  .level-4-wrapper {
    top: 0;
  }

  .level-3-wrapper {
    padding: 20px 0 20px 30px;
    border-left: none;
  }

  .level-3-wrapper > li:last-child {
    margin-top: 50px;
  }

  .level-4-wrapper {
    padding: 20px 0 0 30px;
    grid-template-columns: repeat(2, 1fr);
  }

  .level-4-wrapper > li:first-child {
    margin-bottom: 20px;
  }

  .level-4-wrapper::before {
    left: 10px;
    height: 100%;
  }
}