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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  min-height: 100vh;
  display: flex;
  justify-content: center;
  align-items: center;
  padding: 20px;
}

.container {
  background: white;
  border-radius: 12px;
  box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
  padding: 40px;
  max-width: 500px;
  width: 100%;
}

h1 {
  color: #333;
  margin-bottom: 30px;
  text-align: center;
  font-size: 28px;
}

.input-section {
  display: flex;
  gap: 10px;
  margin-bottom: 20px;
}

input[type="text"] {
  flex: 1;
  padding: 12px 16px;
  border: 2px solid #e0e0e0;
  border-radius: 8px;
  font-size: 16px;
  transition: border-color 0.3s;
}

input[type="text"]:focus {
  outline: none;
  border-color: #667eea;
}

button {
  padding: 12px 24px;
  background: #667eea;
  color: white;
  border: none;
  border-radius: 8px;
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  transition: background 0.3s;
}

button:hover {
  background: #5568d3;
}

button:active {
  transform: scale(0.98);
}

.stats {
  text-align: center;
  color: #666;
  font-size: 14px;
  margin-bottom: 20px;
  padding: 10px;
  background: #f5f5f5;
  border-radius: 6px;
}

.todo-list {
  list-style: none;
}

.todo-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 16px;
  background: #f9f9f9;
  border-radius: 8px;
  margin-bottom: 10px;
  transition: all 0.3s;
}

.todo-item:hover {
  background: #f0f0f0;
  transform: translateX(4px);
}

.todo-item.completed {
  opacity: 0.6;
}

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

input[type="checkbox"] {
  width: 20px;
  height: 20px;
  cursor: pointer;
  accent-color: #667eea;
}

.todo-text {
  flex: 1;
  color: #333;
  font-size: 16px;
}

.delete-btn {
  background: #ff6b6b;
  color: white;
  border: none;
  padding: 8px 12px;
  border-radius: 6px;
  cursor: pointer;
  font-size: 14px;
  transition: background 0.3s;
}

.delete-btn:hover {
  background: #ff5252;
}

.empty-state {
  text-align: center;
  color: #999;
  padding: 40px 20px;
  font-size: 16px;
}