.app-shell{ display:flex; min-height:100vh; }

.sidebar{
  width:var(--sidebar-w); flex-shrink:0; background:var(--surface); border-right:1px solid var(--border);
  display:flex; flex-direction:column; height:100vh; position:sticky; top:0;
  transition:width var(--dur) var(--ease);
  z-index:120;
}
.sidebar.collapsed{ width:var(--sidebar-w-collapsed); }
.sidebar-brand{ display:flex; align-items:center; gap:10px; padding:18px 18px 14px; }
.sidebar-brand .mark{ width:28px; height:28px; flex-shrink:0; }
.sidebar-brand .wordmark{ font-size:15.5px; font-weight:700; letter-spacing:-0.02em; white-space:nowrap; overflow:hidden; }
.sidebar.collapsed .wordmark, .sidebar.collapsed .sidebar-user .meta, .sidebar.collapsed .section-label, .sidebar.collapsed .nav-label, .sidebar.collapsed .nav-badge, .sidebar.collapsed .nav-chevron, .sidebar.collapsed .nav-extlink{ display:none; }

.sidebar-scroll{ flex:1; overflow-y:auto; padding:4px 10px 10px; }
.nav-section{ margin-top:6px; }
.section-header{ display:flex; align-items:center; justify-content:space-between; padding:10px 10px 6px; cursor:pointer; }
.section-label{ font-size:11px; font-weight:700; letter-spacing:0.06em; text-transform:uppercase; color:var(--text-tertiary); }
.section-chevron{ width:14px; height:14px; color:var(--text-tertiary); transition:transform var(--dur); }
.nav-section.collapsed-section .section-chevron{ transform:rotate(-90deg); }
.nav-section.collapsed-section .section-items{ display:none; }
.section-items{ display:flex; flex-direction:column; gap:1px; }

.nav-item{
  display:flex; align-items:center; gap:11px; padding:9px 10px; border-radius:9px;
  color:var(--text-secondary); font-size:13.5px; font-weight:500; position:relative;
  transition:background var(--dur-fast), color var(--dur-fast);
}
.nav-item svg{ flex-shrink:0; }
.nav-item:hover{ background:var(--surface-hover); color:var(--text-primary); }
.nav-item.active{ background:var(--accent-dim); color:var(--accent); font-weight:600; }
.nav-item.active svg{ color:var(--accent); }
.nav-label{ flex:1; white-space:nowrap; overflow:hidden; text-overflow:ellipsis; }
.nav-extlink{ color:var(--text-tertiary); }
.sidebar.collapsed .nav-item{ justify-content:center; }

.sidebar-foot{ border-top:1px solid var(--border); padding:10px; display:flex; flex-direction:column; gap:2px; }
.sidebar-user{ display:flex; align-items:center; gap:10px; padding:9px 8px; border-radius:9px; }
.sidebar-user:hover{ background:var(--surface-hover); cursor:pointer; }
.avatar{ width:32px; height:32px; border-radius:9px; background:var(--accent); color:#fff; display:flex; align-items:center; justify-content:center; font-size:12.5px; font-weight:700; flex-shrink:0; }
.sidebar-user .meta{ overflow:hidden; }
.sidebar-user .meta .name{ font-size:13px; font-weight:600; white-space:nowrap; overflow:hidden; text-overflow:ellipsis; }
.sidebar-user .meta .tier{ font-size:11.5px; color:var(--text-tertiary); }
.collapse-btn{ width:100%; }

.sidebar-scrim{ position:fixed; inset:0; background:rgba(10,12,18,0.4); z-index:110; display:none; }
.sidebar-scrim.open{ display:block; }

@media (max-width:960px){
  .sidebar{ position:fixed; left:0; top:0; height:100vh; transform:translateX(-100%); box-shadow:var(--shadow-lg); width:270px; }
  .sidebar.open{ transform:translateX(0); }
  .sidebar.collapsed{ width:270px; }
  .sidebar.collapsed .wordmark, .sidebar.collapsed .section-label, .sidebar.collapsed .nav-label, .sidebar.collapsed .nav-badge, .sidebar.collapsed .nav-chevron, .sidebar.collapsed .nav-extlink, .sidebar.collapsed .sidebar-user .meta{ display:revert; }
  .sidebar-collapse-desktop{ display:none; }
}

.app-topbar{
  height:var(--topbar-h); border-bottom:1px solid var(--border); background:var(--surface);
  display:flex; align-items:center; justify-content:space-between; padding:0 20px; gap:16px;
  position:sticky; top:0; z-index:90;
}
.topbar-left{ display:flex; align-items:center; gap:14px; min-width:0; }
.mobile-menu-btn{ display:none; }
.crumb{ font-size:15px; font-weight:600; white-space:nowrap; overflow:hidden; text-overflow:ellipsis; }
.topbar-search{
  display:flex; align-items:center; gap:8px; height:36px; padding:0 12px; border-radius:9px;
  background:var(--bg-subtle); border:1px solid transparent; color:var(--text-tertiary); width:260px; cursor:pointer;
  transition:border-color var(--dur-fast);
}
.topbar-search:hover{ border-color:var(--border-strong); }
.topbar-search input{ background:none; border:none; color:var(--text-primary); flex:1; font-size:13px; cursor:pointer; }
.topbar-search kbd{ font-size:10.5px; background:var(--surface); border:1px solid var(--border-strong); border-radius:5px; padding:1px 5px; color:var(--text-tertiary); }
.topbar-right{ display:flex; align-items:center; gap:6px; flex-shrink:0; }
.account-pill{
  display:flex; align-items:center; gap:8px; height:36px; padding:0 12px; border-radius:9px;
  border:1px solid var(--border-strong); background:var(--surface); font-size:12.5px; cursor:pointer;
}
.account-pill:hover{ background:var(--surface-hover); }
.account-pill b{ font-family:var(--font-mono); }
.notif-btn{ position:relative; }
.notif-dot{ position:absolute; top:6px; right:6px; width:7px; height:7px; border-radius:99px; background:var(--negative); border:1.5px solid var(--surface); }

.dropdown{ position:relative; }
.dropdown-panel{
  position:absolute; right:0; top:calc(100% + 8px); background:var(--surface); border:1px solid var(--border);
  border-radius:12px; box-shadow:var(--shadow-lg); min-width:280px; z-index:150; opacity:0; visibility:hidden;
  transform:translateY(-6px); transition:opacity var(--dur-fast), transform var(--dur-fast), visibility var(--dur-fast);
}
.dropdown-panel.open{ opacity:1; visibility:visible; transform:none; }
.dropdown-head{ padding:12px 14px; border-bottom:1px solid var(--border); display:flex; justify-content:space-between; align-items:center; }
.dropdown-head h4{ font-size:13.5px; }
.dropdown-head button{ font-size:12px; color:var(--accent); background:none; border:none; font-weight:600; }
.dropdown-list{ max-height:360px; overflow-y:auto; }
.dropdown-item{ display:flex; gap:10px; padding:11px 14px; border-bottom:1px solid var(--border); }
.dropdown-item:last-child{ border-bottom:none; }
.dropdown-item:hover{ background:var(--surface-hover); }
.dropdown-item .dot-ind{ width:7px; height:7px; border-radius:99px; background:var(--accent); margin-top:5px; flex-shrink:0; }
.dropdown-item.read .dot-ind{ background:transparent; }
.dropdown-item .body{ flex:1; }
.dropdown-item .title{ font-size:12.5px; font-weight:600; }
.dropdown-item .desc{ font-size:12px; color:var(--text-secondary); margin-top:2px; }
.dropdown-item .time{ font-size:11px; color:var(--text-tertiary); margin-top:3px; }
.menu-panel{ min-width:210px; padding:6px; }
.menu-item{ display:flex; align-items:center; gap:10px; padding:9px 10px; border-radius:8px; font-size:13px; font-weight:500; color:var(--text-primary); }
.menu-item:hover{ background:var(--surface-hover); }
.menu-item.danger{ color:var(--negative); }
.menu-sep{ height:1px; background:var(--border); margin:5px 0; }

@media (max-width:960px){
  .mobile-menu-btn{ display:inline-flex; }
  .topbar-search{ width:auto; flex:1; max-width:220px; }
  .account-pill span{ display:none; }
}
@media (max-width:560px){
  .topbar-search{ display:none; }
  .crumb{ font-size:14.5px; }
}

.app-main{ flex:1; min-width:0; display:flex; flex-direction:column; }
.app-content{ padding:22px 24px 60px; max-width:var(--container-max); width:100%; margin:0 auto; }
@media (max-width:640px){ .app-content{ padding:16px 14px 48px; } }

.page-head{ display:flex; align-items:flex-start; justify-content:space-between; gap:16px; margin-bottom:20px; flex-wrap:wrap; }
.page-head .subtitle{ color:var(--text-secondary); font-size:13.5px; margin-top:4px; }
.page-actions{ display:flex; gap:10px; flex-wrap:wrap; }