*, *::before, *::after { box-sizing: border-box; }
body { font-family: system-ui, sans-serif; max-width: 900px; margin: 0 auto; padding: 1rem; }
nav { display: flex; gap: 1rem; align-items: center; margin-bottom: 1rem; padding-bottom: 0.5rem; border-bottom: 1px solid #ccc; }
nav a { text-decoration: none; color: #333; }
nav a:hover { text-decoration: underline; }
label { display: block; margin-bottom: 0.5rem; }
input { display: block; width: 100%; padding: 0.4rem; margin-top: 0.2rem; }
button { padding: 0.4rem 1rem; cursor: pointer; }
.error { color: red; }
.flash { padding: 0.5rem; margin-bottom: 1rem; border-radius: 4px; }
.flash-error { background: #fee; border: 1px solid #fcc; }
.flash-success { background: #efe; border: 1px solid #cfc; }
table { width: 100%; border-collapse: collapse; }
th, td { text-align: left; padding: 0.4rem; border-bottom: 1px solid #eee; }