.timeliner {
  --col-gap: 2rem;
  --row-gap: 2rem;
  --line-w: 0.25rem;
  display: grid;
  grid-template-columns: var(--line-w) 1fr;
  grid-auto-columns: max-content;
  column-gap: var(--col-gap);
  list-style: none;
  width: min(60rem, 90%);
  margin-inline: auto;
}

/* line */
.timeliner::before {
  content: "";
  grid-column: 1;
  grid-row: 1 / span 20;
  background: rgb(225, 225, 225);
  border-radius: calc(var(--line-w) / 2);
}

/* columns*/

/* row gaps */
.timeliner li:not(:last-child) {
  margin-bottom: var(--row-gap);
}

/* card */
.timeliner li {
    margin-top: 10px;
    grid-column: 2;
    grid-row: span 2;
    display: grid;
    grid-template-rows: min-content min-content min-content;
}

ul li .date::after {
  content: "";
  position: absolute;
  width: 2rem;
  aspect-ratio: 1;
  background: var(--bgColor);
  border: 0.3rem solid var(--accent-color);
  border-radius: 50%;
  top: 50%;

  transform: translate(50%, -50%);
  right: calc(100% + var(--col-gap) + var(--line-w) / 2);
}

/* date */
.timeliner li .date {
  height: 3rem;
  text-align: center;
  background-color: var(--accent-color);
  color: white;
  font-size: 1.25rem;
  font-weight: 700;
  display: grid;
  place-content: center;
  position: relative;
  border-radius: 24px;
}
  .timeliner li:nth-child(odd) .date::after {
    transform: translate(-50%, -50%);
    left: calc(100% + var(--col-gap) + var(--line-w) / 2);
  }


/* date flap */
.timeliner li .date::before {
  content: "";
  margin-bottom: 10px;
  background: var(--accent-color);
  
  position: absolute;
  top: 100%;
}

/* title descr */
.timeliner li .title,
.timeliner li .descr {
  background-color: whitesmoke;
  position: relative;
  padding-inline: 1.5rem;
}
.timeliner li .title {
  overflow: hidden;
  padding-block-start: 1.5rem;
  padding-block-end: 1rem;
  font-weight: 500;
}
.timeliner li .descr {
  padding-block-end: 1.5rem;
  font-weight: 300;
}

.timeliner li .title::before {
  bottom: calc(100% + 0.125rem);
}

.timeliner li .descr::before {
  z-index: -1;
  bottom: 0.25rem;
}

@media (min-width: 40rem) {
    .timeliner {
    grid-template-columns: 1fr var(--line-w) 1fr;
  }
  .timeliner::before {
    grid-column: 2;
  }
  .timeliner li:nth-child(odd) {
    grid-column: 1;
  }
  .timeliner li:nth-child(even) {
    grid-column: 3;
  }

  /* start second card */
  .timeliner li:nth-child(2) {
    grid-row: 2/4;
  }
}