body {
    font-family: system-ui, sans-serif;
    margin: 0;
    background: #f5f5f5;
    color: #222;
}
.topnav {
    display: flex;
    align-items: center;
    gap: 1rem;
    background: #1c2b3a;
    color: white;
    padding: 0.75rem 1.5rem;
}
.topnav a { color: white; text-decoration: none; }
.topnav a:hover { text-decoration: underline; }
.spacer { flex: 1; }
.container {
    max-width: 900px;
    margin: 2rem auto;
    padding: 0 1rem;
}
table {
    border-collapse: collapse;
    width: 100%;
    background: white;
}
th, td {
    border: 1px solid #ddd;
    padding: 0.5rem 0.75rem;
    text-align: left;
}
th { background: #eee; }
form { margin-bottom: 1rem; }
input, button {
    padding: 0.4rem;
    font-size: 1rem;
}
button {
    cursor: pointer;
}
section {
    background: white;
    border: 1px solid #ddd;
    padding: 1rem;
    margin-bottom: 1rem;
    border-radius: 4px;
}
.flash {
    padding: 0.5rem 1rem;
    border-radius: 4px;
    margin-bottom: 1rem;
}
.flash.error { background: #fde2e2; color: #7a1f1f; }
.flash.ok { background: #e2fde5; color: #1f7a2e; }