body {
  font-family: Arial, sans-serif;
  background: #f2f4f8;
  display: flex;
  justify-content: center;
  align-items: flex-start;
  min-height: 100vh;
  margin: 0;
  padding: 2rem;
}

.app {
  background: #fff;
  padding: 20px;
  border-radius: 12px;
  box-shadow: 0px 4px 12px rgba(0,0,0,0.1);
  width: 350px;
}

h1 {
  text-align: center;
  margin-bottom: 20px;
  color: #333;
}

.input-container {
  display: flex;
  gap: 8px;
}

#taskInput {
  flex: 1;
  padding: 10px;
  border: 1px solid #ccc;
  border-radius: 8px;
  outline: none;
}

#addTaskBtn {
  padding: 10px 15px;
  background: #4CAF50;
  color: white;
  border: none;
  border-radius: 8px;
  cursor: pointer;
}

#addTaskBtn:hover {
  background: #45a049;
}

ul {
  list-style-type: none;
  padding: 0;
  margin-top: 20px;
}

li {
  display: flex;
  justify-content: space-between;
  align-items: center;
  background: #fafafa;
  padding: 10px;
  margin-bottom: 10px;
  border-radius: 8px;
  transition: background 0.3s ease;
}

li.completed {
  text-decoration: line-through;
  color: #777;
  background: #e0e0e0;
}

button.delete-btn {
  background: #ff4d4d;
  border: none;
  color: white;
  padding: 6px 10px;
  border-radius: 6px;
  cursor: pointer;
}

button.delete-btn:hover {
  background: #e60000;
}