html, body {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: Helvetica, Arial, sans-serif;
}

.header__wrapper {
  display: flex;
  justify-content: center;
  align-items: center;
  height: 70px;
  margin: auto;
}

.menu__item {
  margin-right: 10px;
  color: black;
  text-decoration: none;
}

.menu__item:last-of-type {
  margin-right: 0;
}

.keyframes {
  background-color: #02B341;
  color: #fff;
}

.keyframes__wrapper {
  width: 490px;
  margin: auto;
  padding: 50px 0;
}

.title {
  margin: 0;
  line-height: 56px;
  font-size: 54px;
}

.subtitle {
  line-height: 19px;
  font-size: 14px;
  margin-top: 35px;
  margin-bottom: 55px;
  max-width: 350px;
}

.demo {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
}

.demo__item {
  box-sizing: border-box;
  border: 2px solid white;
  border-radius: 50%;
  width: 240px;
  height: 240px;
  margin-right: 10px;
  margin-top: 10px;
}

.demo__item:nth-of-type(2n) {
  margin-right: 0;
}

.demo__item:first-of-type, .demo__item:nth-of-type(2) {
  margin-top: 0;
}

.demo__row {
  height: 64px;
}

.dotted {
  background-color: #EB483F;
  color: white;
}

.dotted__wrapper {
  width: 490px;
  margin: auto;
  padding: 50px 0;
  min-height: 350px;
  position: relative;
}

.animated {
  width: 490px;
  height: 350px;
  position: absolute;
  left: 0;
  bottom: 0;
  transform: translate(0, 50%);
}

.star {
  position: absolute;
  top: 50%;
  left: 50%;
}

.star_s {
  width: 310px;
  height: 310px;
  margin-left: -155px;
  margin-top: -155px;
}

.star_l {
  width: 420px;
  height: 420px;
  margin-left: -210px;
  margin-top: -210px;
}

.star_m {
  width: 420px;
  height: 420px;
  margin-left: -210px;
  margin-top: -210px;
}

.dots {
  position: absolute;
  top: 50%;
  left: 50%;
  width: 490px;
  height: 460px;
  margin-top: -245px;
  margin-left: -230px;
}

.demo__row_xs {
  background-image: url(https://pictures.s3.yandex.net/animation_topic/line_xs.svg);
}

.demo__row_s {
  background-image: url(https://pictures.s3.yandex.net/animation_topic/line_s.svg);
}

.demo__row_m {
  background-image: url(https://pictures.s3.yandex.net/animation_topic/line_m.svg);
}

.demo__row_l {
  background-image: url(https://pictures.s3.yandex.net/animation_topic/line_l.svg);
}