:root{--bar-h: 52px;--accent: #1a73e8;--touch: 44px}*{box-sizing:border-box}html,body,#root{height:100%;margin:0}body{font-family:system-ui,-apple-system,Noto Sans KR,sans-serif;overscroll-behavior:none;-webkit-text-size-adjust:100%}.shell{display:flex;flex-direction:column;height:100%}.topbar{height:var(--bar-h);display:flex;align-items:center;gap:12px;padding:0 12px;background:#202124;color:#fff;flex-wrap:nowrap}.brand{font-weight:700}.conn-status{display:flex;align-items:center;gap:8px;font-size:14px}.conn-dot{width:10px;height:10px;border-radius:50%;display:inline-block}.conn-mode{font-size:12px;opacity:.7}.conn-status button{min-height:32px;padding:0 12px;border-radius:6px;border:none;background:var(--accent);color:#fff;cursor:pointer}.conn-status button:disabled{opacity:.5;cursor:default}.tab-switch{display:none;margin-left:auto;gap:4px}.tab-switch button{min-height:var(--touch);padding:0 14px;border:none;border-radius:8px;background:#3c4043;color:#fff}.tab-switch button.on{background:var(--accent)}.split{flex:1;display:flex;min-height:0}.pane{min-width:0;min-height:0;height:100%}.editor-pane{flex:1 1 60%;border-right:1px solid #dadce0}.content-pane-wrap{flex:1 1 40%;background:#f8f9fa;overflow:auto}.content-pane{display:flex;flex-direction:column;height:100%}.content-empty{padding:24px;color:#5f6368}.content-video{width:100%;height:100%;background:#000}.pdf-canvas-wrap{flex:1;overflow:auto;display:flex;justify-content:center;padding:12px}.pdf-canvas{max-width:100%;height:auto;box-shadow:0 1px 6px #0003}.pdf-nav{display:flex;align-items:center;justify-content:center;gap:16px;padding:8px;background:#fff;border-top:1px solid #dadce0}.pdf-nav button{min-width:var(--touch);min-height:var(--touch);font-size:18px;border:none;border-radius:8px;background:#e8eaed;cursor:pointer}@media (max-width: 900px){.tab-switch{display:flex}.split{position:relative}.pane{position:absolute;inset:0;display:none;flex:none;width:100%}.pane.show{display:block}.editor-pane{border-right:none}}@media (hover: none){button{-webkit-tap-highlight-color:transparent}}.boot{display:grid;place-items:center;height:100%;color:#5f6368}.login-wrap{display:grid;place-items:center;height:100%;background:#f1f3f4}.login-card{background:#fff;padding:32px;border-radius:12px;box-shadow:0 2px 12px #0000001a;display:flex;flex-direction:column;gap:12px;width:min(360px,90vw)}.login-card h1{margin:0;color:var(--accent)}.login-card input{min-height:var(--touch);padding:0 12px;border:1px solid #dadce0;border-radius:8px;font-size:16px}.login-card button{min-height:var(--touch);border:none;border-radius:8px;background:var(--accent);color:#fff;font-size:16px}.login-card button:disabled{opacity:.5}.login-err{color:#d93025;font-size:14px}.course-select{min-height:32px;border-radius:6px;border:none;padding:0 8px}.logout{margin-left:8px;min-height:32px;border:none;border-radius:6px;background:#3c4043;color:#fff;padding:0 12px}.lesson-list{list-style:none;margin:0;padding:8px;display:flex;gap:8px;overflow-x:auto;border-bottom:1px solid #dadce0}.lesson-list button{white-space:nowrap;min-height:36px;padding:0 12px;border:1px solid #dadce0;border-radius:18px;background:#fff}.lesson-list button:disabled{opacity:.5}.badge{font-size:11px;background:#e8eaed;border-radius:4px;padding:1px 5px;margin-left:4px}.locked{display:grid;place-items:center;height:100%;text-align:center;color:#5f6368;padding:24px}.buy-btn{min-height:var(--touch);padding:0 20px;border:none;border-radius:8px;background:#34a853;color:#fff;font-size:16px;margin-top:12px}.buy-btn:disabled{opacity:.5}.admin-toggle{min-height:32px;border:none;border-radius:6px;background:#5f6368;color:#fff;padding:0 12px}.single{flex:1;overflow:auto;background:#f8f9fa}.seat-admin{max-width:720px;margin:0 auto;padding:24px}.seat-admin input{min-height:var(--touch);padding:0 12px;border:1px solid #dadce0;border-radius:8px;width:100%;max-width:360px}.seat-msg{background:#e6f4ea;color:#137333;padding:8px 12px;border-radius:8px;margin-bottom:12px}.seat-pool-list{list-style:none;padding:0;display:flex;flex-direction:column;gap:8px}.seat-pool-list li{display:flex;align-items:center;justify-content:space-between;gap:12px;background:#fff;padding:12px;border-radius:8px;border:1px solid #dadce0}.seat-pool-list button{min-height:36px;padding:0 16px;border:none;border-radius:8px;background:var(--accent);color:#fff}.seat-pool-list button:disabled{opacity:.5}.seat-exp{color:#9aa0a6;font-size:13px}.seat-assign-row,.seat-release-row{margin:12px 0;display:flex;flex-direction:column;gap:4px}