* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}
body {
  font-family: 'Segoe UI', sans-serif;
  background: linear-gradient(135deg, #a1c4fd, #c2e9fb);
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: flex-start;
  padding-top: 60px;
}
.container {
  background: #ffffff;
  padding: 30px 25px;
  border-radius: 15px;
  width: 400px;
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
  transition: 0.3s ease;
}
.container:hover {
  transform: translateY(-3px);
}
h1 {
  text-align: center;
  color: #4b0082;
  margin-bottom: 20px;
}
.input-section {
  display: flex;
  gap: 10px;
  margin-bottom: 25px;
}
input[type="text"] {
  flex: 1;
  padding: 12px;
  font-size: 16px;
  border-radius: 8px;
  border: 1px solid #bbb;
  outline: none;
  transition: border-color 0.3s ease;
}
input[type="text"]:focus {
  border-color: #6a5acd;
}
button {
  background-color: #6a5acd; 
  border: none;
  color: white;
  padding: 12px 15px;
  border-radius: 8px;
  cursor: pointer;
  transition: background-color 0.3s ease;
}
button:hover {
  background-color: #4b0082;
}
ul {
  list-style: none;
}
li {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 14px;
  margin-bottom: 12px;
  background: #f3e8ff; 
  border-radius: 8px;
  transition: 0.2s ease;
}
li:hover {
  background: #e0d5ff;
}
li.completed span {
  text-decoration: line-through;
  color: #888;
}
li span {
  flex: 1;
  cursor: pointer;
  user-select: none;
}
.remove-btn {
  background-color: #20b2aa;
  color: white;
  border: none;
  padding: 6px 10px;
  border-radius: 6px;
  cursor: pointer;
  transition: background-color 0.3s ease;
}
.remove-btn:hover {
  background-color: #138a84;
}