:root {
  --bg: #f6f7f9;
  --surface: #ffffff;
  --border: #dfe3e8;
  --text: #1d2228;
  --muted: #6b7280;
  --accent: #2563eb;
  --danger: #b42318;
  --radius: 8px;
}

* {
  box-sizing: border-box;
}

body {
  margin: 0;
  padding: 48px 16px;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.5 system-ui, -apple-system, "Segoe UI", sans-serif;
}

.app {
  max-width: 560px;
  margin: 0 auto;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 28px;
}

.app__title {
  margin: 0 0 20px;
  font-size: 24px;
  font-weight: 600;
}

.add {
  display: flex;
  gap: 8px;
  margin-bottom: 16px;
}

.add__input {
  flex: 1;
  padding: 10px 12px;
  font: inherit;
  color: inherit;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}

.add__input:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 1px;
}

.add__button {
  padding: 10px 18px;
  font: inherit;
  font-weight: 500;
  color: #fff;
  background: var(--accent);
  border: 1px solid var(--accent);
  border-radius: var(--radius);
  cursor: pointer;
}

.filters {
  display: flex;
  gap: 6px;
  margin-bottom: 16px;
}

.filters__button {
  padding: 6px 14px;
  font: inherit;
  font-size: 14px;
  color: var(--muted);
  background: transparent;
  border: 1px solid var(--border);
  border-radius: 999px;
  cursor: pointer;
}

.filters__button[aria-pressed="true"] {
  color: var(--accent);
  border-color: var(--accent);
  background: #eff4ff;
}

.list {
  margin: 0;
  padding: 0;
  list-style: none;
}

.task {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 10px 0;
  border-bottom: 1px solid var(--border);
}

.task:last-child {
  border-bottom: 0;
}

.task__checkbox {
  width: 18px;
  height: 18px;
  flex: none;
  accent-color: var(--accent);
  cursor: pointer;
}

.task__name {
  flex: 1;
  word-break: break-word;
}

.task--done .task__name {
  color: var(--muted);
  text-decoration: line-through;
}

.task__delete {
  padding: 4px 10px;
  font: inherit;
  font-size: 14px;
  color: var(--danger);
  background: transparent;
  border: 1px solid transparent;
  border-radius: var(--radius);
  cursor: pointer;
}

.task__delete:hover {
  border-color: var(--danger);
}

.empty {
  margin: 20px 0 0;
  color: var(--muted);
  text-align: center;
}