CSSでツリーを作る。

ツリーにマウスカーソルを乗せるとメッセージが出てくる。

HTML

<div class="tree">
  <div class="leaves green"></div>
  <div class="trunk brown"></div>
  <p class="message">Merry Christmas</p>
</div>

CSS

.tree{
  position: relative;
  width: 100px;
  height: 100px;
}

.tree .leaves{
  position: absolute;
  bottom: 15%;
  left: 50%;
  border: 40px solid transparent;
  border-bottom: 30px solid currentColor;
  transform: translate(-50%,-50%);
  box-sizing: border-box;
  z-index: 2;
}

/* 共通部分 */
.tree .leaves:before,
.tree .leaves:after{
  position: absolute;
  content: "";
  border: inherit;
  border-bottom: inherit;
  box-sizing: inherit;
}

.tree .leaves:before{
  transform: translate(-50%,-35%) scale(1.15,1.13);
}

.tree .leaves:after{
  transform: translate(-50%,-18%) scale(1.3,1.25);
}

.tree .trunk{
  position: absolute;
  bottom: 0;
  left: 50%;
  width: 20%;
  height: 20%;
  border-radius: 10% / 20%;
  background-color: currentColor;
  transform: translateX(-50%);
  z-index: 1;
}

.tree .message{
  position: absolute;
  bottom: 0;
  left: 50%;
  display: inline-block;
  margin: 0;
  font-size: 2rem;
  letter-spacing: -2rem;
  color: transparent;
  white-space: nowrap;
  transition: 1s;
}

.tree:hover > .message{
  left: 100%;
  letter-spacing: 0;
  color: red;
}

/* 色 */
.green{
  color: green;
}

.brown{
  color: #9D3718;
}

leaves(葉)の部分はborderで三角形を作って表現しています。