*, *::before, *::after { box-sizing: border-box; }

body {
    margin: 0;
    font-family: system-ui, sans-serif;
    color: #222;
}

.layout {
    max-width: 960px;
    margin: 0 auto;
    padding: 0 1rem;
}

.navbar {
    display: flex;
    align-items: center;
    gap: 1rem;
    padding: 0.75rem 0;
    border-bottom: 1px solid #ddd;
    margin-bottom: 1.5rem;
}

.navbar .spacer { flex: 1; }

.error { color: #c00; }
.success { color: #070; }

input { padding: 0.4rem; margin: 0.25rem 0; width: 100%; max-width: 320px; display: block; }
button { padding: 0.4rem 1rem; cursor: pointer; margin-top: 0.5rem; }
dt { font-weight: bold; margin-top: 0.5rem; }