:root{--rail-width: 60px;--subpanel-width: 220px;--header-height: 44px;--color-bg: #f5f6f8;--color-rail: #1f2733;--color-rail-active: #3a4658;--color-accent: #2f6fed;--color-border: #d8dce3}*{box-sizing:border-box}html,body,#root{height:100%;margin:0}body{font-family:system-ui,-apple-system,Segoe UI,sans-serif;color:#1f2733;background:var(--color-bg)}.centered{display:flex;flex-direction:column;align-items:center;justify-content:center;height:100%;gap:8px;text-align:center;padding:24px}.hub{display:flex;flex-direction:column;height:100%}.hub-header{height:var(--header-height);display:flex;align-items:center;justify-content:space-between;padding:0 12px;border-bottom:1px solid var(--color-border);background:#fff}.hub-tenant{font-size:12px;color:#6b7280;font-family:ui-monospace,monospace}.hub-logout{border:1px solid var(--color-border);background:#fff;border-radius:6px;padding:4px 12px;cursor:pointer;font-size:13px}.hub-logout:hover{background:#f0f1f3}.hub-body{flex:1;display:flex;min-height:0}.rail{width:var(--rail-width);flex:0 0 var(--rail-width);background:var(--color-rail);display:flex;flex-direction:column;align-items:center;padding:8px 0;gap:8px}.rail-btn{width:44px;height:44px;border:none;border-radius:10px;background:transparent;cursor:pointer;display:flex;align-items:center;justify-content:center;padding:0}.rail-btn:hover,.rail-btn--active{background:var(--color-rail-active)}.menu-icon{width:24px;height:24px;object-fit:contain;display:block}.menu-icon--placeholder{display:flex;align-items:center;justify-content:center;color:#fff;font-weight:600;font-size:14px;border-radius:6px;background:#4b5563}.subpanel{width:var(--subpanel-width);flex:0 0 var(--subpanel-width);border-right:1px solid var(--color-border);background:#fff;padding:12px;overflow-y:auto}.subpanel-title{font-size:13px;text-transform:uppercase;letter-spacing:.04em;color:#6b7280;margin:0 0 8px}.subpanel-list{list-style:none;margin:0;padding:0;display:flex;flex-direction:column;gap:2px}.leaf-btn,.leaf-link{display:block;width:100%;text-align:left;border:none;background:transparent;padding:8px 10px;border-radius:6px;cursor:pointer;font-size:14px;color:inherit;text-decoration:none}.leaf-btn:hover,.leaf-link:hover{background:#eef1f6}.leaf-btn--active{background:#e3ecfd;color:var(--color-accent);font-weight:600}.leaf-divider{border:none;border-top:1px solid var(--color-border);margin:6px 0}.hub-main{flex:1;min-width:0;display:flex}.appframe{flex:1;width:100%;height:100%;border:none}.appframe--empty{display:flex;align-items:center;justify-content:center;color:#6b7280}