.workspace.dual[data-split-workspace]{grid-template-columns:var(--workspace-split-columns,minmax(0,1fr) 10px minmax(0,1fr));grid-template-rows:minmax(0,1fr);overflow:hidden;gap:0}
.workspace.dual[data-split-workspace]>.pane{min-height:0;min-width:0;overflow-y:auto;overflow-x:hidden;border:0}
.workspace-separator{position:relative;align-self:stretch;cursor:col-resize;touch-action:none;outline:0;background:#e0e8ef;z-index:15;min-width:10px}
.workspace-separator::before{content:'';position:absolute;left:4px;top:0;bottom:0;width:2px;background:#b7c8d7}
.workspace-separator::after{content:'';position:absolute;left:2px;top:calc(50% - 22px);width:6px;height:44px;border-radius:5px;background:#94acc0}
.workspace-separator:hover,.workspace-separator:focus-visible,.workspace-resizing>.workspace-separator{background:#ccdeed}
.workspace-separator:focus-visible::after{background:#315f83;box-shadow:0 0 0 2px #f4f7fa}
.workspace-resizing,.workspace-resizing *{cursor:col-resize!important;user-select:none!important}
.workspace-resizing iframe{pointer-events:none!important}
.external-page{display:flex;flex-direction:column;gap:6px;min-width:0;padding-top:2px}
.external-page-form{display:flex;gap:8px;align-items:end;flex-wrap:wrap;margin:0}
.external-page-address{display:flex;flex:1 1 220px;min-width:0;flex-direction:column;gap:2px;font-size:11px}
.external-page-address input{width:100%;box-sizing:border-box}
.external-page-link{align-self:flex-start;font-size:12px}
.external-page-note{margin:0;color:var(--muted,#657d90);font-size:11px;line-height:1.3}
.external-page-error{margin:0;color:#a72834;font-size:12px}
.external-page-frame{display:block;box-sizing:border-box;width:100%;height:clamp(320px,calc(100vh - 190px),1600px);min-height:320px;border:1px solid var(--line,#cbd9e4);border-radius:8px;background:#fff}
.external-page-empty{display:grid;place-items:center;min-height:260px;border:1px dashed var(--line,#cbd9e4);border-radius:8px;color:var(--muted,#657d90);padding:24px;text-align:center}
.external-page [hidden]{display:none!important}
@media(max-width:760px){.workspace.dual[data-split-workspace]{grid-template-columns:minmax(0,1fr);grid-template-rows:auto auto;overflow:auto}.workspace.dual[data-split-workspace]>.pane{overflow:visible;min-height:400px}.workspace.dual[data-split-workspace]>.pane~.pane{border-top:2px solid var(--line,#cbd9e4)}.workspace-separator{display:none}.external-page-frame{height:60vh}}

.external-page-favorites{display:flex;gap:6px;align-items:end;flex-wrap:wrap}
.external-page-favorites label{display:flex;flex:1 1 170px;min-width:0;flex-direction:column;gap:2px;font-size:11px}
.external-page-favorites input,.external-page-favorites select{max-width:100%;box-sizing:border-box}
.external-page-favorites button{font-size:12px;white-space:nowrap}
.main.dual-main .topbar{padding:6px 16px;min-height:0;gap:10px}
.main.dual-main .page-title{font-size:17px;line-height:1.2}
.main.dual-main .page-sub{display:none}
.main.dual-main .top-actions{gap:6px}
.main.dual-main .top-actions>.btn,.main.dual-main .desktop-sidebar-toggle{padding:6px 9px;font-size:11px}
.workspace.dual[data-split-workspace]>.pane{padding:0 12px 10px}
.workspace.dual .pane-selector{padding:4px 0 6px;gap:6px}
.workspace.dual .pane-selector select{padding:6px 8px}
.workspace.dual .pane-selector .pane-expand{flex:none;padding:5px 9px;font-size:16px;line-height:1}
.workspace.dual[data-split-workspace][data-expanded-pane="0"],.workspace.dual[data-split-workspace][data-expanded-pane="1"]{grid-template-columns:minmax(0,1fr);grid-template-rows:minmax(0,1fr)}
.workspace.dual[data-split-workspace]>.pane[hidden],.workspace.dual[data-split-workspace]>.workspace-separator[hidden]{display:none!important}
.workspace.dual[data-split-workspace]>.pane-external-page{display:flex;flex-direction:column}
.pane-external-page>.pane-view{display:flex;flex:1;min-height:0;flex-direction:column}
.pane-external-page .external-page{flex:1;min-height:0}
.pane-external-page [data-external-frame-host]{display:flex;flex:1;min-height:0}
.pane-external-page .external-page-frame{flex:1;height:100%;min-height:320px}
.pane-external-page .external-page-address input,.pane-external-page .external-page-favorites input,.pane-external-page .external-page-favorites select{padding:6px 8px}
@media(max-width:1100px){.main.dual-main .topbar{flex-wrap:wrap}.main.dual-main .top-actions{flex-wrap:wrap}}

/* Pane identity stays fixed: mirroring changes grid placement, never DOM ownership. */
.workspace>.pane[hidden],.workspace>.workspace-separator[hidden]{display:none!important}
.workspace:not(.dual){grid-template-columns:minmax(0,1fr)}
.workspace.dual[data-split-workspace]>.pane{grid-row:1}
.workspace.dual[data-split-workspace]>.pane[data-pane="0"]{grid-column:1}
.workspace.dual[data-split-workspace]>.pane[data-pane="1"]{grid-column:3}
.workspace.dual[data-split-workspace]>.workspace-separator{grid-column:2;grid-row:1}
.workspace.dual[data-split-workspace][data-mirrored="true"]>.pane[data-pane="0"]{grid-column:3}
.workspace.dual[data-split-workspace][data-mirrored="true"]>.pane[data-pane="1"]{grid-column:1}
.workspace.dual[data-split-workspace][data-expanded-pane]>.pane:not([hidden]){grid-column:1;grid-row:1}
.top-actions [data-action="swap-panes"]{padding-inline:10px;font-size:18px;line-height:1}
.top-actions [data-action="swap-panes"][hidden]{display:none!important}
@media(max-width:760px){
 .workspace.dual[data-split-workspace]>.pane[data-pane]{grid-column:1;grid-row:auto}
 .workspace.dual[data-split-workspace]>.pane[data-pane="0"]{grid-row:1}
 .workspace.dual[data-split-workspace]>.pane[data-pane="1"]{grid-row:2}
 .workspace.dual[data-split-workspace][data-mirrored="true"]>.pane[data-pane="0"]{grid-column:1;grid-row:2}
 .workspace.dual[data-split-workspace][data-mirrored="true"]>.pane[data-pane="1"]{grid-column:1;grid-row:1}
 .workspace.dual[data-split-workspace][data-expanded-pane]>.pane:not([hidden]){grid-column:1;grid-row:1}
}