body { font: 15px/1.5 system-ui, sans-serif; max-width: 46rem; margin: 1.5rem auto; padding: 0 1rem; }
header { display: flex; justify-content: space-between; align-items: baseline; border-bottom: 1px solid #ddd; }
nav a { margin-right: 1rem; } .hidden { display: none; }
fieldset { border: 1px solid #ccc; border-radius: 8px; margin: 1rem 0; }
label { display: block; margin: .4rem 0; } input, select { padding: .4rem; }
button { padding: .45rem .9rem; cursor: pointer; margin-top: .5rem; }
table { width: 100%; border-collapse: collapse; margin-top: 1rem; }
th, td { border: 1px solid #ddd; padding: .4rem; text-align: left; font-size: 14px; }
pre { background: #f4f4f4; padding: .8rem; overflow: auto; } .msg { color: #0a6; }