.app-shell { display: flex; min-height: 100vh; }
.app-sidebar { width: 200px; flex: 0 0 200px; background: #1a2230; color: #cfd8e3;
  padding: 16px 10px; border-right: 1px solid #2c3a4d; position: sticky; top: 0;
  height: 100vh; overflow-y: auto; box-sizing: border-box; }
.sidebar-brand { font-size: 15px; font-weight: 700; color: #fff; padding: 6px 10px 14px; letter-spacing: .5px; }
.sidebar-nav { display: flex; flex-direction: column; gap: 2px; }
.nav-group { font-size: 11px; text-transform: uppercase; letter-spacing: 1px; color: #7f8fa4; margin: 14px 10px 6px; }
.nav-item { display: block; padding: 8px 10px; border-radius: 6px; color: #cfd8e3; text-decoration: none; font-size: 13px; }
.nav-item:hover { background: #263247; color: #fff; }
.nav-item.active { background: #2563eb; color: #fff; font-weight: 600; }
.app-shell > .app-main { flex: 1; min-width: 0; padding: 16px 20px; }
/* F-1：多租户登录区（auth.js render() 替换内容，容器仅提供间距/分隔） */
.sidebar-auth { margin-top: 14px; padding: 12px 10px 4px; border-top: 1px solid #2c3a4d; font-size: 13px; color: #cfd8e3; }
.sidebar-auth input { background: #121a26; color: #cfd8e3; border: 1px solid #2c3a4d; border-radius: 5px; padding: 4px 6px; }
.sidebar-auth button.primary { background: #2563eb; color: #fff; border: none; border-radius: 5px; }
.sidebar-auth .link-btn { background: none; border: none; color: #7fb2ff; cursor: pointer; padding: 2px 4px; }