* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: "Poppins", sans-serif;
}

body {
  height: 100vh;
  background: linear-gradient(135deg, #6a11cb, #2575fc);
  display: flex;
  justify-content: center;
  align-items: center;
}

.container {
  width: 100%;
  display: flex;
  justify-content: center;
}

.todo-box {
  background: #fff;
  padding: 30px;
  border-radius: 20px;
  box-shadow: 0 5px 15px rgba(0,0,0,0.3);
  width: 350px;
  text-align: center;
}

.todo-box h2 {
  margin-bottom: 20px;
  color: #333;
}

.input-area {
  display: flex;
  justify-content: center;
  margin-bottom: 20px;
}

#taskInput {
  flex: 1;
  padding: 10px;
  border: 2px solid #ddd;
  border-radius: 8px;
  font-size: 14px;
}

#addBtn {
  padding: 10px 15px;
  border: none;
  background: #22c55e;
  color: white;
  border-radius: 8px;
  margin-left: 8px;
  cursor: pointer;
  font-weight: bold;
  transition: 0.3s;
}

#addBtn:hover {
  background: #16a34a;
}

ul {
  list-style: none;
  max-height: 300px;
  overflow-y: auto;
}

li {
  background: #f1f5f9;
  padding: 10px;
  margin: 5px 0;
  border-radius: 8px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

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

button.delete {
  background: #ef4444;
  border: none;
  color: white;
  padding: 5px 8px;
  border-radius: 6px;
  cursor: pointer;
}

button.delete:hover {
  background: #dc2626;
}