:root {
  color-scheme: light;
  --page: #f5f5f0;
  --surface: #ffffff;
  --ink: #24342c;
  --muted: #626f64;
  --green: #254c3d;
  --green-light: #eaf0e9;
  --line: #e0e5dc;
  font-family: "Segoe UI", "Noto Sans TC", "Microsoft JhengHei", sans-serif;
  font-synthesis: none;
  -webkit-font-smoothing: antialiased;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  background: var(--page);
  color: var(--ink);
  line-height: 1.6;
}

button, input { font: inherit; }
button { cursor: pointer; }
button, input { transition: background-color 160ms ease, border-color 160ms ease; }
button:focus-visible, input:focus-visible {
  outline: 3px solid #8cac76;
  outline-offset: 3px;
}

/* Match the current .app / .app-header HTML structure. */
.app {
  width: min(780px, calc(100% - 48px));
  margin: 64px auto;
}
.app-header { margin-bottom: 32px; }
.app-header h1 {
  margin: 0;
  font-size: clamp(26px, 4vw, 36px);
  font-weight: 650;
  line-height: 1.4;
  overflow-wrap: anywhere;
}
.app-header p { margin: 12px 0 0; color: var(--muted); }
.app > main {
  background: var(--surface);
  border: 1px solid var(--line);
  border-radius: 16px;
  box-shadow: 0 4px 24px #203c2b06;
}

.add-task-section { padding: 28px; border-bottom: 1px solid var(--line); }
.add-task-section label { display: block; margin-bottom: 12px; font-weight: 600; }
.input-group { display: flex; gap: 12px; }
.input-group input[type="text"] {
  flex: 1;
  min-width: 0;
  width: 100%;
  min-height: 48px;
  padding: 10px 14px;
  border: 1px solid #cbd5c5;
  border-radius: 8px;
  background: #fbfcf9;
  color: var(--ink);
}
.input-group input::placeholder { color: var(--muted); opacity: 1; }
.input-group input:hover { border-color: #789474; }
.add-btn {
  flex-shrink: 0;
  min-height: 48px;
  padding: 10px 22px;
  border: 1px solid var(--green);
  border-radius: 8px;
  background: var(--green);
  color: #fff;
  font-weight: 600;
}
.add-btn:hover { background: #35644f; border-color: #35644f; }

.filter-section { display: flex; flex-wrap: wrap; gap: 8px; padding: 24px 28px 12px; }
.filter-btn {
  min-height: 44px;
  padding: 8px 20px;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #f6f7f3;
  color: var(--muted);
}
.filter-btn:hover { background: var(--green-light); color: var(--green); }
.filter-btn.active { background: var(--green); border-color: var(--green); color: #fff; }

.task-section { padding: 0 28px; }
.task-list { list-style: none; margin: 0; padding: 0; }
.task-item {
  display: flex;
  align-items: center;
  gap: 16px;
  min-height: 84px;
  padding: 18px 0;
  border-bottom: 1px solid var(--line);
}
.task-item:last-child { border-bottom: 0; }
.task-content { display: flex; align-items: center; flex: 1; min-width: 0; gap: 14px; }
.task-content input[type="checkbox"] {
  flex-shrink: 0;
  width: 22px;
  height: 22px;
  margin: 0;
  accent-color: var(--green);
  cursor: pointer;
}
.task-content span { min-width: 0; overflow-wrap: anywhere; }
.task-item.completed .task-content span { color: var(--muted); text-decoration: line-through; }
.delete-btn {
  flex-shrink: 0;
  min-height: 44px;
  padding: 8px 14px;
  border: 1px solid #e5d9d3;
  border-radius: 8px;
  background: #fff;
  color: #975645;
}
.delete-btn:hover { background: #fcf0ec; border-color: #c68f7e; }

.stats-section {
  display: flex;
  flex-wrap: wrap;
  gap: 12px 28px;
  padding: 18px 28px;
  border-top: 1px solid var(--line);
  border-radius: 0 0 16px 16px;
  background: #fafbf8;
  color: var(--muted);
  font-size: 14px;
}
.stats-section span { white-space: nowrap; }
.stats-section strong { color: var(--green); font-variant-numeric: tabular-nums; }

@media (max-width: 480px) {
  .app { width: calc(100% - 32px); margin: 32px auto; }
  .app-header { margin-bottom: 24px; }
  .app-header p { font-size: 14px; }
  .add-task-section { padding: 20px 18px; }
  .input-group { flex-direction: column; gap: 10px; }
  .add-btn { width: 100%; }
  .filter-section { padding: 20px 18px 8px; gap: 6px; }
  .filter-btn { flex: 1; padding: 8px; font-size: 14px; }
  .task-section { padding: 0 18px; }
  .task-item { gap: 10px; }
  .task-content { gap: 10px; font-size: 14px; }
  .delete-btn { padding: 8px 10px; font-size: 14px; }
  .stats-section { padding: 16px 18px; gap: 10px 16px; font-size: 13px; }
}

@media (prefers-reduced-motion: reduce) {
  button, input { transition: none; }
}