body { font-family: system-ui, sans-serif; max-width: 640px; margin: 2rem auto; padding: 0 1rem; }
nav a, nav button { margin-right: 1rem; }
nav form { display: inline; }
nav button { background: none; border: 0; color: #06c; cursor: pointer; font: inherit; padding: 0; }
input { display: block; margin: .4rem 0 1rem; padding: .4rem; width: 100%; box-sizing: border-box; }
.flash { background: #eef; padding: .5rem 1rem; border-radius: 4px; margin-bottom: 1rem; }