react18-tools/react-mouse-trail

.header {
  position: sticky;
  top: 0;
  width: 100%;
  height: 76px;
  box-shadow: 0 3px 8px -6px var(--text-color);
  backdrop-filter: blur(3px);
  z-index: 100;
  & > div {
    display: flex;
    align-items: center;
    flex-wrap: nowrap !important;
    font-size: 0.85rem;
    max-width: var(--max-width);
    width: 100%;
    height: 100%;
    z-index: 2;
    padding: 0 10px;
    margin: auto;
  }
  nav {
    position: fixed;
    top: 76px;
    height: calc(100vh - 76px);
    left: -300px;
    width: 300px;
    box-shadow: 0 0 8px -5px var(--text-color);
    overflow: auto;
    display: flex;
    flex-direction: column-reverse;
    gap: 20px;
    justify-content: space-between;
    background: var(--bg-color);
  }
  .open {
    left: 0;
  }
}

.author,
.themeswitch {
  all: unset;
  box-shadow: 0 1px 8px -5px var(--text-color);
  padding: 15px 20px;
  gap: 20px;
  display: flex;
  text-transform: capitalize;
  cursor: pointer;
  margin: 0;
}
.author {
  font-weight: 700;
  font-size: 1rem;
  justify-content: center;
  text-shadow: 0 1px 5px orange;
}

@media screen and (min-width: 800px) {
  .header {
    & > div {
      justify-content: space-between;
    }
    nav {
      position: relative;
      flex-direction: row;
      align-items: center;
      height: 100%;
      width: auto;
      top: 0;
      left: auto;
      background: transparent;
    }
    nav,
    .author,
    .themeswitch {
      box-shadow: none;
      text-shadow: none;
      font-weight: 500;
      gap: 0;
    }
  }
  .themeswitch {
    margin-right: 130px;
  }
}

@media screen and (min-width: 1200px) {
  .themeswitch {
    margin-right: 80px;
  }
}