todos.css

h1{
  background-color: #2980b9;
  color: white;
  margin: 0;
  padding: 10px 20px;
  text-transform: uppercase;
  font-weight: 400;
}
div{
  position:absolute;
  left:38%;
  top:10%;

}
canvas{
  position:fixed;
   left: 0;
   top: 0;
   z-index:-1;
  width:100%;
  background-color: black;
  height: 100%;
}
body ,html{
  margin: 0;
  height: 100%;
  font-family: Roboto;
}

ul{
  list-style: none;
  margin:0;
  padding: 0;
}
/* i{
  text-align: right;
} */
.fa-plus{
    float:right;
}

li{
  background-color: #fff;
  height:40px;
  line-height:40px;
  color:#666;
}

input{
  color:#2980b9;
  font-size: 18px;
  background-color: #f7f7f7;
  width:100%;
  padding: 13px 13px 13px 20px;
  box-sizing: border-box;
  border:3px solid rgba(0,0,0,0);
}
input:focus{
  background-color: white;
  outline: none;
  border: 2px solid #2980b9;
}
li:nth-child(2n){
  background-color: #f7f7f7;
}

.container {
  width: 360px;
  margin: 100px auto;
  background-color : #f7f7f7;
  box-shadow: 0 0 3px rgba(0,0,0,0.1);
}
.completed{
  color : gray ;
  text-decoration : line-through;
}
span{
  background-color: #e74c3c;
  height: 40px;
  text-align: center;
  color:white;
  width: 0;
  opacity: 0;
  display: inline-block;
  margin-right :20px;
  transition: 0.2s linear;
}
li:hover span{
  opacity: 1.0;
  width: 40px;
}