/* Board (multi-pane iframe) base styles */
html, body { margin: 0; height: 100%; }
.col { display: flex; flex-direction: column; overflow: hidden; flex: 0 0 auto; }
.box { flex: 0 0 auto; min-width: 200px; min-height: 200px; position: relative; overflow: hidden; background: #0f0f0f; font: 14px/1.4 system-ui, Arial, sans-serif; color: #b2b2b2; }
.box iframe { position: absolute; inset: 0; width: 100%; height: 100%; border: 0; background: #0f0f0f; }
.box.placeholder { display: flex; align-items: center; justify-content: center; text-align: center; padding: 1rem; background: linear-gradient(135deg,#151a22,#0f0f0f); letter-spacing: .3px; }
.box.placeholder span { opacity: .7; max-width: 340px; }
.gutter { background: #132c76; }
.gutter-horizontal { cursor: col-resize; width: 3px; }
.gutter-vertical { cursor: row-resize; height: 3px; }