main {
  overflow: hidden;
  padding-top: 100px;
  padding-bottom: 50px;
}

.courses-header {
  font-size: 1.6em;
  position: relative;
  margin-left: 30px;
}

.courses-header::before {
  content: "";
  position: absolute;
  z-index: -1;
  top: -100%;
  left: -85px;
  width: 80px;
  height: 80px;
  background-position: center;
  background-size: cover;
  border-radius: 50%;
}

#course-header1::before {
  background-image: url("../../static/icons/run.png");
}

#course-header2::before {
  background-image: url("../../static/icons/hot-stones.png");
}

#course-header3::before {
  background-image: url("../../static/icons/dumbbells.png");
}

.hero-section {
  min-height: 60vh;
}

.sub-header {
  font-size: 1.4em;
  position: relative;
}

.sub-header::after {
  content: "";
  background-color: transparent;
  width: 15vw;
  height: 15vw;
  border-radius: 50%;
  border: 5px solid var(--green);
  position: absolute;
  top: 0;
  left: 5vw;
  z-index: -1;
}

.sub-header::before {
  content: "";
  background-color: transparent;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: 5px solid var(--green);
  position: absolute;
  bottom: 20px;
  right: 30px;
  z-index: -1;
}

.main-content {
  padding: 0 calc(5vw + 40px);
  display: flex;
  flex-direction: column;
  gap: 2em;
}

.main-content div {
  position: relative;
}

.main-content div::before {
  content: "";
  width: 30px;
  height: 30px;
  background-color: var(--green);
  position: absolute;
  border-radius: 50%;
  top: 50%;
  transform: translateY(-50%);
  left: -40px;
}

.main-content div:nth-child(even):before {
  content: "";
  width: 30px;
  height: 30px;
  background-color: var(--blue);
  position: absolute;
  border-radius: 50%;
  top: 50%;
  transform: translateY(-50%);
  left: -40px;
}

#back-to-top-btn {
  margin: 50px 50px 0 auto;
  width: 100px;
  height: 100px;
  border-radius: 50%;
  background-color: var(--green);
  display: flex;
  justify-content: center;
  align-items: center;
  transition: all 0.3s ease;
}

#back-to-top-btn:hover {
  background-color: rgb(204, 234, 14);
}

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/* RWDRWDRWDRWDRWDRWDRWDRWDRWDRWDRWDRWDRWDRWDRWDRWDRWDRWDRWDRWD */
/* RWDRWDRWDRWDRWDRWDRWDRWDRWDRWDRWDRWDRWDRWDRWDRWDRWDRWDRWDRWD */

@media screen and (min-width: 450px) {
  .sub-header::after {
    width: 15vw;
    height: 15vw;
    left: 12vw;
  }

  .sub-header::before {
    width: 10vw;
    height: 10vw;
    right: 14vw;
  }

  .sub-header {
    font-size: 2.2em;
  }
}

@media screen and (min-width: 768px) {
  .sub-header::after {
    display: none;
  }

  .sub-header::before {
    width: 25vw;
    height: 25vw;
    right: 2vw;

    background-color: var(--green);
  }

  .sub-header {
    font-size: 2em;
    margin-bottom: 0;
  }

  .sub-header h1 {
    text-align: left;
  }
}

@media screen and (min-width: 992px) {
  .nav-container {
    padding-top: 10px;
  }

  .hero-header h1 {
    padding-left: 50px;
    line-height: 1;
  }

  .sub-header::before {
    right: 3vw;
    top: 20px;
  }

  .sub-header {
    font-size: 2.4em;
  }

  .scrolldown {
    display: none;
  }
}

@media screen and (min-width: 1200px) {
  .sub-header::before {
    right: 15vw;
    top: 0px;
  }

  .hero-header {
    margin-top: 22vh;
  }

  .sub-header {
    font-size: 2.6em;
  }
}