* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: Arial, sans-serif;
  background: #f4f4f5;
  color: #222;
}

.app {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
}

.todo-card {
  width: 100%;
  max-width: 480px;
  background: white;
  border-radius: 16px;
  padding: 24px;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.08);
}

.title {
  margin: 0;
  font-size: 28px;
}

.subtitle {
  margin-top: 8px;
  margin-bottom: 20px;
  color: #666;
  font-size: 14px;
}

.todo-form {
  display: flex;
  gap: 8px;
}

.todo-form input {
  flex: 1;
  padding: 12px;
  border: 1px solid #ddd;
  border-radius: 10px;
  font-size: 14px;
}

.todo-form input:focus {
  outline: none;
  border-color: #999;
}

.todo-form button {
  border: none;
  background: #222;
  color: white;
  padding: 12px 16px;
  border-radius: 10px;
  cursor: pointer;
  font-size: 14px;
}

.todo-form button:hover {
  opacity: 0.9;
}

.error-message {
  min-height: 18px;
  margin: 8px 0 0;
  color: #d92d20;
  font-size: 13px;
}

.filter-buttons {
  display: flex;
  gap: 8px;
  margin-top: 16px;
}

.filter-btn {
  border: 1px solid #ddd;
  background: white;
  border-radius: 8px;
  padding: 8px 12px;
  cursor: pointer;
  font-size: 13px;
}

.filter-btn:hover {
  background: #f2f2f2;
}

.filter-btn.active {
  background: #222;
  color: white;
  border-color: #222;
}

.todo-list {
  list-style: none;
  padding: 0;
  margin: 16px 0 0;
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.todo-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 8px;
  padding: 12px;
  background: #fafafa;
  border: 1px solid #eee;
  border-radius: 10px;
}

.todo-text {
  flex: 1;
  word-break: break-word;
}

.todo-actions {
  display: flex;
  gap: 6px;
}

.action-btn {
  border: 1px solid #ddd;
  background: white;
  border-radius: 8px;
  padding: 6px 10px;
  cursor: pointer;
  font-size: 12px;
}

.action-btn:hover {
  background: #f2f2f2;
}

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