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

body {
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  background-color: #f5f5f5;
  min-height: 100vh;
  padding: 2rem 1rem;
}

.container {
  max-width: 500px;
  margin: 0 auto;
}

h1 {
  text-align: center;
  margin-bottom: 1.5rem;
  color: #333;
}

.todo-form {
  display: flex;
  gap: 0.5rem;
  margin-bottom: 0.75rem;
}

.filter-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.75rem;
  margin-bottom: 1.25rem;
}

.filter-buttons {
  display: inline-flex;
  gap: 0.5rem;
  flex-wrap: wrap;
}

.filter-btn {
  border: 1px solid #ddd;
  background: white;
  color: #333;
  border-radius: 999px;
  padding: 0.35rem 0.75rem;
  font-size: 0.9rem;
  cursor: pointer;
}

.filter-btn[aria-pressed="true"] {
  border-color: #333;
  background: #333;
  color: white;
}

.filter-btn:focus-visible {
  outline: 2px solid #4a90d9;
  outline-offset: 2px;
}

.todo-count {
  margin: 0;
  color: #666;
  font-size: 0.9rem;
}

.todo-input {
  flex: 1;
  padding: 0.75rem 1rem;
  font-size: 1rem;
  border: 2px solid #ddd;
  border-radius: 6px;
  outline: none;
}

.todo-input:focus {
  border-color: #4a90d9;
}

.add-btn {
  padding: 0.75rem 1.25rem;
  font-size: 1rem;
  background-color: #4a90d9;
  color: white;
  border: none;
  border-radius: 6px;
  cursor: pointer;
}

.add-btn:hover {
  background-color: #3a7bc8;
}

.add-btn:focus-visible {
  outline: 2px solid #4a90d9;
  outline-offset: 2px;
}

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

.todo-item {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  padding: 0.75rem 1rem;
  background-color: white;
  border-radius: 6px;
  margin-bottom: 0.5rem;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
}

.todo-item.completed .todo-text {
  text-decoration: line-through;
  color: #888;
}

.todo-checkbox {
  width: 1.25rem;
  height: 1.25rem;
  cursor: pointer;
}

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

.delete-btn {
  padding: 0.4rem 0.6rem;
  font-size: 0.875rem;
  background-color: #e74c3c;
  color: white;
  border: none;
  border-radius: 4px;
  cursor: pointer;
}

.delete-btn:hover {
  background-color: #c0392b;
}

.delete-btn:focus-visible {
  outline: 2px solid #e74c3c;
  outline-offset: 2px;
}

.empty-state {
  text-align: center;
  color: #888;
  padding: 2rem 0;
}

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}