/* Login/register gate only (index.php). Tokens from css/app.css. */
body {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    margin: 0;
    background: var(--surface-alt);
}
.auth-card { width: 100%; max-width: 440px; }
.auth-tabs { display: flex; border-bottom: 2px solid var(--border-soft); margin-bottom: 20px; }
.auth-tab-btn {
    flex: 1;
    text-align: center;
    padding: 12px;
    font-weight: bold;
    background: none;
    border: 0;
    cursor: pointer;
    color: var(--text-muted);
    font-size: 15px;
    border-bottom: 2px solid transparent;
    margin-bottom: -2px;
}
.auth-tab-btn.active { color: var(--primary); border-color: var(--primary); }