body { font-family: system-ui, sans-serif; max-width: 640px; margin: 40px auto; }
section { border: 1px solid #ddd; border-radius: 8px; padding: 16px; margin-bottom: 24px; }
button { cursor: pointer; padding: 6px 12px; }
input { padding: 6px; width: 100%; box-sizing: border-box; }
.hint { color: #888; font-size: 13px; }
.counter { font-size: 24px; }
.toggle { font-size: 12px; font-weight: normal; padding: 2px 8px; margin-left: 8px; }
ul { padding-left: 20px; }