body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  padding: 100px;
  text-align: center;
  background: linear-gradient(to right, cornflowerblue, crimson);
  margin: 0;
}

.container {
  padding: 30px;
  background-color: white;
  border: none;
  border-radius: 50px;
  width: 90%;
  margin: auto;
  max-width: 500px;
}

.input-section {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  flex-wrap: wrap;
}

input {
  padding: 12px;
  border: 3px solid grey;
  border-radius: 10px;
  font-size: 15px;
  width: 60%;
}

button {
  background-color: chartreuse;
  border: 3px solid chartreuse;
  border-radius: 10px;
  padding: 10px 20px;
  font-size: 15px;
  font-weight: 800;
  cursor: pointer;
}

ul {
  padding: 0;
  margin-top: 20px;
}

li {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background-color: #e2dddd;
  padding: 10px 15px;
  border-radius: 10px;
  margin-bottom: 10px;
  width: 100%;
  box-sizing: border-box;
}

li:hover {
  background-color: darkgrey;
}

li button {
  padding: 8px;
  background-color: cornflowerblue;
  border: none;
  color: white;
  font-weight: bold;
  border-radius: 6px;
  cursor: pointer;
}

li.completed {
  text-decoration: line-through;
  background-color: rgb(255, 255, 255);
}

@media (max-width: 768px) {
  .container {
    width: 60%;
  }

  input {
    width: 90%;
  }

  .input-section {
    flex-direction: column;
    gap: 12px;
  }

  li {
    width: 100%;
    flex-direction: row;
    justify-content: space-between;
  }
}

@media (max-width: 480px) {
  .container {
    width: 85%;
    padding: 20px;
  }

  #click {
    width: 80%;
  }

  button {
    width: 40%;
  }

  input {
    width: 70%;
  }
}

@media (max-width: 390px) {
  .container {
    width: 95%;
    padding: 15px;
    border-radius: 30px;
  }

  input, button {
    width: 70%;
    font-size: 14px;
  }

  li {
    flex-direction: column;
    align-items: flex-start;
    font-size: 1.2rem;
  }

  li button {
    font-size: 1rem;
    margin-top: 6px;
  }
}