index.css

* {
    padding: 0;
    margin: 0;
}
html {
    width: 100%;
    height: 100%;

}
body {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 100%;
    height: 100%;
}
.container {
    width: 100%;
    height: 100%;
    display: flex;
    flex-direction: column;
}
header {
    height: 60px;
    background-color: #f5f5f5;
    border: 1px solid #ddd;
    border-radius: 4px;
    line-height: 50px;
    font-size: 30px;
    color: rgb(211, 208, 169);
}
.border, #myCanvas{
    border: 1px solid #ddd;
    border-radius: 3px;
}
.info{
    display: block;
    height: 10%;
}

.tool{
    height:10%;
    display: flex;
    flex-direction: row;
}
section {
    height: 500px;
}

.icon {
  width: 2em;
  height: 2em;
  vertical-align: -0.15em;
  fill: currentColor;
  overflow: hidden;
}

#lineColor{
    display: none;
}