body {
  font-family: Arial, Helvetica, sans-serif;
}
.container {
  width: 750px;
  margin: 20px auto;
}
@media (max-width: 767px) {
  .container {
    width: 500px;
  }
}
@media (max-width: 567px) {
  .container {
    width: 290px;
  }
}
.form {
  background-color: #eee;
  border-radius: 6px;
  padding: 20px;
  display: flex;
  align-items: center;
}
@media (max-width: 567px) {
  .form {
    flex-direction: column;
  }
}
.input {
  padding: 10px;
  border: 1px solid #ddd;
  border-radius: 6px;
  flex: 1;
}
@media (max-width: 567px) {
  .input {
    width: 90%;
    margin-bottom: 10px;
  }
}
.input:focus {
  outline: none;
}
.add {
  border: none;
  background-color: #009688;
  color: white;
  padding: 10px;
  border-radius: 6px;
  margin-left: 10px;
  cursor: pointer;
}
@media (max-width: 567px) {
  .add {
    margin-left: 0;
  }
}
.tasks {
  background-color: #eee;
  margin-top: 20px;
  border-radius: 6px;
  padding: 20px;
}
.tasks .task {
  background-color: white;
  padding: 10px;
  border-radius: 6px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: 0.3s;
  cursor: pointer;
  border: 1px solid #ccc;
  position: relative;
  transition: 0.3s;
  -webkit-transition: 0.3s;
  -moz-transition: 0.3s;
  -ms-transition: 0.3s;
  -o-transition: 0.3s;
}
@media (max-width: 567px) {
  .tasks .task {
    font-size: 12px;
  }
}
.tasks .task:not(:last-child) {
  margin-bottom: 15px;
}
.tasks .task:hover {
  background-color: #f7f7f7;
}
.tasks .task.done {
  opacity: 0.5;
}
.tasks .task.done::before {
  content: "";
  position: absolute;
  height: 1px;
  background-color: #5f5f5f;
  width: 80%;
}
@media (max-width: 567px) {
  .tasks .task.done::before {
    width: 70%;
  }
}
.tasks .task span {
  font-weight: bold;
  font-size: 13px;
  background-color: red;
  color: white;
  padding: 2px 6px;
  border-radius: 4px;
  cursor: pointer;
}
@media (max-width: 567px) {
  .tasks .task span {
    font-size: 10px;
  }
}