body {
  background: #f7f7f7;
  font-family: Arial, sans-serif;
  margin: 0;
  padding: 0;
}

.container {
  background: #fff;
  max-width: 400px;
  margin: 60px auto;
  padding: 30px 20px 20px 20px;
  border-radius: 8px;
  box-shadow: 0 4px 24px rgba(0,0,0,0.08);
}

h1 {
  text-align: center;
  margin-bottom: 24px;
  color: #333;
}

form {
  display: flex;
  gap: 10px;
  margin-bottom: 18px;
}

input[type="text"] {
  flex: 1;
  padding: 8px;
  border-radius: 4px;
  border: 1px solid #ddd;
  font-size: 16px;
}

button {
  padding: 8px 16px;
  background: #0099ff;
  color: #fff;
  border: none;
  border-radius: 4px;
  font-size: 16px;
  cursor: pointer;
}

button:hover {
  background: #007acc;
}

ul {
  list-style-type: none;
  padding: 0;
  margin: 0;
}

li {
  background: #fafafa;
  border: 1px solid #ececec;
  padding: 10px 8px;
  margin-bottom: 10px;
  border-radius: 4px;
  display: flex;
  align-items: center;
  transition: background 0.2s;
}

li.completed {
  text-decoration: line-through;
  color: #999;
  background: #e5f7e5;
}

li .delete-btn {
  margin-left: auto;
  background: none;
  border: none;
  color: #ff2d55;
  font-size: 18px;
  cursor: pointer;
}

li .delete-btn:hover {
  color: #b22222;
}

li .check-btn {
  margin-right: 10px;
  background: none;
  border: none;
  color: #0099ff;
  font-size: 18px;
  cursor: pointer;
}

li .check-btn:hover {
  color: #007acc;
}