#main-img {
  width: calc(var(--img-block-width) - var(--standart-margin));
}

.article-plain {
  padding: 15px;
}

#article {
  display: flex;
  flex-direction: column;
  align-items: center;
}

#article .article-chapter {
  margin-bottom: var(--standart-margin);
}

#article :last-child {
  margin-bottom: 0;
}

.article-chapter {
  width: var(--chapter-width);
}

@media (max-width: 768px) {
  .article-chapter {
    width: auto;
    max-width: var(--chapter-width);
  }
}

.article-chapter-with-img {
  display: flex;
}

.article-chapter div {
  margin-right: var(--standart-margin);
}

.article-chapter :last-child {
  margin-right: 0;
}

@media (max-width: 768px) {
  .article-chapter-with-img {
    flex-direction: column;
    align-items: center;
  }

  .article-chapter div {
    margin-right: 0;
  }
}

.img-block {
  width: var(--img-block-width);
}

.img-block img {
  margin-right: var(--standart-margin);
}

.img-block :last-child {
  margin-right: 0;
}

.img-block {
  flex-shrink: 0;
  flex-grow: 1;
}

.text-block {
  max-width: calc(
    var(--chapter-width) - var(--img-block-width) - var(--standart-margin)
  );
}

@media (max-width: 768px) {
  .text-block {
    max-width: 100%;
  }
}

#img-11 {
  width: var(--img11-width);
}

#img-12 {
  width: var(--img12-width);
}

#img-21 {
  width: calc(var(--img-block-width) - var(--standart-margin));
}

:root {
  --chapter-width: 992px;
  --standart-margin: 20px;
  --img-block-width: 360px;
}

@media (max-width: 1199px) {
  :root {
    --chapter-width: 768px;
  }
}

@media (max-width: 992px) {
  :root {
    --chapter-width: 640px;
    --img-block-width: 320px;
  }
}

@media (max-width: 768px) {
  :root {
    --chapter-width: 425px;
    --img-block-width: 300px;
  }
}

@media (max-width: 450px) {
  :root {
    --img-block-width: 240px;
  }
}

@media (max-width: 320px) {
  :root {
    --img-block-width: 180px;
  }
}

:root {
  --img11-width: calc(
    (var(--img-block-width) - var(--standart-margin)) * 42 / 100
  );
  --img12-width: calc(
    (var(--img-block-width) - var(--standart-margin)) * 53 / 100
  );
}