:root{--board-bg:#10251d}.board-modal-card{width:min(1380px,97vw);height:min(930px,96vh);display:flex;flex-direction:column;overflow:hidden}.board-title{display:flex;align-items:flex-start;justify-content:space-between;gap:16px;padding-right:40px}.board-title h2{margin:0}.board-title p{margin:5px 0 0;color:var(--muted);font-size:13px}.board-meta{text-align:right;font-size:12px;color:var(--muted)}.board-toolbar{display:flex;flex-wrap:wrap;align-items:center;gap:8px;padding:12px 0;border-bottom:1px solid var(--border)}.board-toolbar button,.board-file-label{border:1px solid var(--border);background:var(--panel-2);color:var(--text);border-radius:9px;padding:8px 11px;cursor:pointer;font-weight:700;font-size:13px}.board-toolbar button:hover,.board-file-label:hover{border-color:var(--accent);background:color-mix(in srgb,var(--accent) 10%,var(--panel-2))}.board-toolbar button.active{background:var(--accent)!important;color:#fff!important;border-color:var(--accent)!important;box-shadow:0 0 0 3px color-mix(in srgb,var(--accent) 24%,transparent)}.board-toolbar.read-only button[data-board-tool],.board-toolbar.read-only .board-file-label,.board-toolbar.read-only #boardUndo{opacity:.45;pointer-events:none}.board-toolbar input[type=color]{width:42px;height:34px;padding:2px;border:1px solid var(--border);border-radius:8px;background:var(--panel-2)}.board-toolbar input[type=range]{width:110px}.board-file-label input{display:none}.board-canvas-wrap{position:relative;flex:1;min-height:300px;margin-top:12px;border:1px solid var(--border);border-radius:14px;overflow:auto;background:var(--panel-2);display:block;scrollbar-gutter:stable both-edges}.board-canvas-stage{position:relative;margin:12px;box-shadow:0 2px 16px rgba(0,0,0,.18);flex:none}.board-canvas-stage canvas{display:block;width:100%;height:100%;touch-action:none;cursor:crosshair;background:var(--board-bg)}.board-help{display:flex;justify-content:space-between;gap:16px;color:var(--muted);font-size:12px;padding-top:9px}.board-help strong{color:var(--text)}[data-theme=light]{--board-bg:#edf4ef}.board-toolbar-sep{width:1px;height:28px;background:var(--border);margin:0 2px}.board-zoom-controls{display:flex;align-items:center;gap:5px}.board-zoom-controls button{min-width:38px;padding:8px}.board-zoom-controls span{min-width:52px;text-align:center;font-weight:800;color:var(--text);font-variant-numeric:tabular-nums}[data-theme=light] .board-toolbar button.active{color:#fff!important;background:#b91c1c!important;border-color:#7f1d1d!important;box-shadow:0 0 0 3px rgba(185,28,28,.2)}[data-theme=light] .board-toolbar button:not(.active),[data-theme=light] .board-file-label{background:#fff;color:#172033;border-color:#b9c4d3}[data-theme=light] .board-canvas-wrap{background:#dbe3ec;border-color:#9aa9ba}[data-theme=light] .board-canvas-stage{outline:1px solid #94a3b8}.board-permission{display:flex;align-items:center;gap:14px;flex-wrap:wrap;margin-top:12px;padding:10px 12px;border:1px solid var(--border);border-radius:10px;background:var(--panel-2)}.board-permission label{display:flex;align-items:center;gap:8px;font-weight:800;color:var(--text);cursor:pointer}.board-permission input{width:18px;height:18px;accent-color:var(--accent)}.board-permission span{font-size:12px;color:var(--muted)}.board-toolbar.student-edit .board-manage-only{display:none!important}.board-toolbar.read-only input[type=color],.board-toolbar.read-only input[type=range]{opacity:.45;pointer-events:none}@media(max-width:700px){.board-modal-card{width:100vw;height:100vh;max-height:none;border-radius:0}.board-toolbar{gap:5px}.board-toolbar button,.board-file-label{padding:7px 8px;font-size:12px}.board-help{flex-direction:column;gap:3px}.board-canvas-stage{margin:6px}}