* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: Arial, sans-serif;
  background: linear-gradient(135deg, #667eea, #764ba2);
  color: #333;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  padding: 15px;
}

.container {
  background: #fff;
  padding: 25px;
  border-radius: 12px;
  max-width: 400px;
  width: 100%;
  box-shadow: 0px 6px 15px rgba(0,0,0,0.2);
}

.container h1 {
  text-align: center;
  margin-bottom: 20px;
  color: #4f46e5;
}

.todo-input {
  display: flex;
  gap: 10px;
  margin-bottom: 15px;
}

.todo-input input {
  flex: 1;
  padding: 10px;
  border-radius: 6px;
  border: 1px solid #ccc;
  font-size: 14px;
}

.todo-input button {
  padding: 10px 15px;
  border: none;
  border-radius: 6px;
  background: #4f46e5;
  color: white;
  font-weight: bold;
  cursor: pointer;
  transition: 0.3s;
}

.todo-input button:hover {
  background: #4338ca;
}

ul {
  list-style: none;
}

ul li {
  background: #f9f9f9;
  margin: 8px 0;
  padding: 10px;
  border-radius: 6px;
  display: flex;
  justify-content: space-between;
  align-items: center;
  transition: 0.3s;
}

ul li.completed {
  text-decoration: line-through;
  background: #d1fae5;
  color: #047857;
}

ul li button {
  margin-left: 8px;
  border: none;
  background: none;
  cursor: pointer;
  font-size: 14px;
}

.scoreboard {
  margin-top: 15px;
  text-align: center;
  font-weight: bold;
  color: #111827;
}