:root,:root[data-theme=dark]{--bg: #1a1a1a;--bg2: #0f0f0f;--panel: #242424;--panel2: #2d2d2d;--panel3: #333333;--border: #3a3a3a;--text: #f1f5f9;--muted: #9aa3ad;--blue: #0078d4;--blue-hover: #106ebe;--green: #00a76f;--green-hover: #00955f;--red: #e74c3c;--red-hover: #c0392b;--indigo: #6366f1;--indigo-hover: #4f46e5;--ring: rgba(0, 120, 212, .35);--shadow: 0 8px 24px rgba(0, 0, 0, .4)}:root[data-theme=light]{--bg: #f3f4f6;--bg2: #e5e7eb;--panel: #ffffff;--panel2: #f3f4f6;--panel3: #e5e7eb;--border: #d1d5db;--text: #0f172a;--muted: #64748b;--blue: #0078d4;--blue-hover: #106ebe;--green: #00a76f;--green-hover: #00955f;--red: #e74c3c;--red-hover: #c0392b;--indigo: #6366f1;--indigo-hover: #4f46e5;--ring: rgba(0, 120, 212, .25);--shadow: 0 4px 12px rgba(15, 23, 42, .1)}:root[data-theme=dark] .theme-icon-light,:root[data-theme=light] .theme-icon-dark{display:none}.icon-btn{background:transparent;border:1px solid var(--border);color:var(--text);width:34px;height:34px;border-radius:50%;display:inline-flex;align-items:center;justify-content:center;cursor:pointer;transition:background .15s}.icon-btn:hover{background:var(--panel2)}*{box-sizing:border-box;transition:background-color .2s,border-color .2s,box-shadow .2s}body{margin:0;font-family:Inter,system-ui,-apple-system,sans-serif;background:var(--bg);color:var(--text);height:100vh;-webkit-font-smoothing:antialiased}#app{height:100vh;display:flex;flex-direction:column}header{padding:12px 20px;background:var(--panel);display:flex;align-items:center;gap:16px;border-bottom:1px solid var(--border)}.header-left{flex:1;min-width:0;display:flex;align-items:center;gap:12px}.header-right{display:flex;align-items:center;gap:8px;color:var(--muted);font-size:13px}.dot-sep{color:var(--border)}.brand-logo{height:28px;width:auto;color:var(--indigo);flex-shrink:0}.header-divider{width:1px;height:24px;background:var(--border);flex-shrink:0}.role-badge{display:inline-flex;align-items:center;padding:3px 10px;border-radius:999px;font-size:11px;font-weight:700;text-transform:uppercase;letter-spacing:.5px;white-space:nowrap}.role-badge.role-teacher{background:#00a76f2e;color:var(--green);border:1px solid rgba(0,167,111,.3)}.role-badge.role-student{background:#6366f12e;color:var(--indigo);border:1px solid rgba(99,102,241,.3)}.course-title{font-size:16px;font-weight:700;color:var(--text);min-width:0;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}header label{color:var(--muted);font-size:13px;font-weight:500}header input,header select{padding:8px 12px;border-radius:8px;border:1px solid var(--border);background:var(--panel);color:var(--text);outline:none;min-width:140px;font-size:14px}header input:focus,header select:focus{border-color:var(--blue);box-shadow:0 0 0 3px var(--ring)}header button{padding:8px 16px;border-radius:8px;border:1px solid transparent;cursor:pointer;background:var(--blue);color:#fff;font-weight:600;font-size:14px;display:flex;align-items:center;justify-content:center;gap:6px}header button:hover{background:var(--blue-hover)}header button.secondary{background:var(--panel2);color:var(--text);border:1px solid var(--border)}header button.secondary:hover{background:#e2e8f0}header button.secondary.active{background:var(--green);color:#fff;border-color:var(--green-hover)}header button.secondary.inactive{background:var(--red);color:#fff;border-color:var(--red-hover)}header #screenBtn.active{background:var(--indigo);border-color:var(--indigo-hover)}header #screenBtn.inactive{background:var(--panel2);color:var(--text);border-color:var(--border)}header #screenBtn.inactive:hover{background:#e2e8f0}header button.danger{background:var(--red);color:#fff}header button.danger:hover{background:var(--red-hover)}header button:disabled{opacity:.5;cursor:not-allowed}#statusBar{padding:6px 20px;font-size:12px;background:var(--bg2);border-bottom:1px solid var(--border);color:var(--muted)}#main{display:flex;flex:1;min-height:0;overflow:hidden;background:var(--bg)}#videosWrap{flex:1;display:flex;flex-direction:column;min-width:0;padding:16px;gap:12px}#stage{flex:1;display:flex;align-items:center;justify-content:center;gap:12px;min-height:0;flex-wrap:wrap}#stage:empty:before{content:"Waiting for the lesson to start…";color:var(--muted);font-size:14px}#stage .tile{flex:1 1 0;height:100%;max-height:100%;min-width:280px}#thumbs{display:flex;gap:10px;overflow-x:auto;padding-bottom:4px;min-height:0;flex-shrink:0;scrollbar-width:thin}#thumbs:empty{display:none}#thumbs .tile{flex:0 0 320px;height:180px;aspect-ratio:unset}#sidebar{display:flex;flex-direction:column;background:var(--panel);width:340px;min-width:280px;border-left:1px solid var(--border);position:relative}#sidebarBackdrop{display:none}.sidebar-close{display:none;position:absolute;top:8px;right:8px;z-index:2}.mobile-only{display:none}#sidebarTabs{display:flex;background:var(--panel);border-bottom:1px solid var(--border)}.side-tab{flex:1;background:transparent;border:none;color:var(--muted);padding:14px 8px;cursor:pointer;font-size:13px;font-weight:600;display:flex;align-items:center;justify-content:center;gap:8px;border-bottom:2px solid transparent}.side-tab:hover{color:var(--text);background:var(--panel2)}.side-tab.active{color:var(--blue);border-bottom-color:var(--blue)}.tab-badge{background:var(--panel3);color:var(--text);padding:1px 8px;border-radius:10px;font-size:11px;font-weight:700}.side-pane{display:none;flex:1;min-height:0;flex-direction:column}.side-pane.active{display:flex}.tile{position:relative;background:#000;border-radius:12px;overflow:hidden;border:1px solid var(--border);aspect-ratio:16 / 9;box-shadow:var(--shadow);display:flex;align-items:center;justify-content:center;transition:all .3s ease}.tile.teacher-tile{border:2px solid var(--green);box-shadow:0 0 0 2px #00a76f33,var(--shadow)}.tile.screen-tile{border:2px solid var(--blue)}.tile video{width:100%;height:100%;object-fit:cover;display:block}.badge{position:absolute;left:12px;bottom:12px;background:#0009;color:#fff;padding:4px 10px;border-radius:6px;font-size:12px;font-weight:500;-webkit-backdrop-filter:blur(4px);backdrop-filter:blur(4px)}#messages{flex:1;padding:16px;overflow:auto;font-size:14px;display:flex;flex-direction:column;gap:10px;min-height:0;background:var(--panel)}.msg{border:1px solid var(--border);background:var(--panel2);color:var(--text);border-radius:14px;padding:10px 14px;max-width:85%}.msg .meta{font-size:12px;color:var(--muted);margin-bottom:4px;font-weight:600}#participantsContent{flex:1;overflow-y:auto;padding:8px;display:flex;flex-direction:column;gap:4px}.participant-item{display:flex;align-items:center;gap:12px;padding:10px;border-radius:10px;transition:background .2s}.participant-item:hover{background:var(--panel2)}.pi-avatar{width:38px;height:38px;border-radius:50%;background:var(--blue);display:flex;align-items:center;justify-content:center;font-weight:700;font-size:15px;color:#fff}.pi-info{flex:1;min-width:0}.pi-name{font-weight:600;font-size:14px;color:var(--text);white-space:nowrap;overflow:hidden;text-overflow:ellipsis}.pi-status{font-size:12px;color:var(--muted)}.teacher-badge{font-size:10px;background:#00a76f26;color:var(--green);padding:2px 6px;border-radius:4px;font-weight:800;text-transform:uppercase;margin-left:4px;vertical-align:middle}.msg.me{align-self:flex-end;background:var(--blue);border-color:var(--blue);color:#fff}.msg.me .meta{color:#ffffffd9}#chatInput{display:flex;gap:8px;border-top:1px solid var(--border);padding:12px;background:var(--panel)}#chatInput input{flex:1;padding:10px 14px;border:1px solid var(--border);background:var(--panel2);color:var(--text);border-radius:20px;outline:none;font-size:14px}#chatInput input::placeholder{color:var(--muted)}#chatInput input:focus{border-color:var(--blue);background:var(--panel);box-shadow:0 0 0 3px var(--ring)}#chatInput button{width:40px;height:40px;padding:0;border:none;background:var(--blue);color:#fff;cursor:pointer;border-radius:50%;display:flex;align-items:center;justify-content:center;flex-shrink:0;transition:transform .1s,background-color .2s}#chatInput button:hover{background:var(--blue-hover);transform:scale(1.05)}#chatInput button:active{transform:scale(.95)}#chatInput button svg{width:20px;height:20px;fill:currentColor}.small{font-size:12px;color:var(--muted)}:root{--admin-bg: #ffffff;--admin-card: #ffffff;--admin-accent: #089c35;--admin-accent-hover: #06862d;--admin-text: #0f172a;--admin-text-muted: #64748b;--glass-border: #e2e8f0;--purple-gradient: linear-gradient(135deg, #6366f1 0%, #a855f7 100%);--blue-gradient: linear-gradient(135deg, #3b82f6 0%, #2dd4bf 100%);--green-gradient: linear-gradient(135deg, #10b981 0%, #34d399 100%)}.admin-container{min-height:100vh;background-color:var(--admin-bg);color:var(--admin-text);font-family:Inter,-apple-system,BlinkMacSystemFont,sans-serif;display:flex;flex-direction:column}.admin-nav{height:64px;display:flex;align-items:center;justify-content:space-between;padding:0 2rem;background:#fffc;-webkit-backdrop-filter:blur(12px);backdrop-filter:blur(12px);border-bottom:1px solid var(--glass-border);position:sticky;top:0;z-index:100}.admin-nav .logo{font-size:1.25rem;font-weight:800;letter-spacing:-.025em;color:var(--admin-text)}.admin-nav .logo span{color:var(--admin-accent)}.admin-content{flex:1;padding:2rem;max-width:1200px;margin:0 auto;width:100%}.admin-header{margin-bottom:3rem}.admin-header h1{font-size:2.25rem;font-weight:800;margin-bottom:.5rem;color:var(--admin-text)}.admin-header p{color:var(--admin-text-muted);font-size:1.1rem}.stats-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(300px,1fr));gap:1.5rem;margin-bottom:3rem}.admin-container .glass{background:var(--admin-card);-webkit-backdrop-filter:blur(16px);backdrop-filter:blur(16px);border:1px solid var(--glass-border);border-radius:1rem;box-shadow:0 4px 6px -1px #0000001a,0 2px 4px -1px #0000000f}.stat-card{padding:1.5rem;display:flex;align-items:center;gap:1.5rem;transition:transform .2s,box-shadow .2s}.stat-card:hover{transform:translateY(-4px);box-shadow:0 20px 25px -5px #0003}.stat-icon{font-size:2.5rem;width:64px;height:64px;display:flex;align-items:center;justify-content:center;border-radius:12px;background:#f8fafc;border:1px solid #e2e8f0}.stat-info .stat-value{font-size:2rem;font-weight:800;line-height:1;color:var(--admin-text)}.stat-info .stat-label{color:var(--admin-text-muted);font-size:.875rem;font-weight:500;margin-top:.25rem}.purple{border-left:4px solid #a855f7!important}.blue{border-left:4px solid #3b82f6!important}.green{border-left:4px solid #10b981!important}.admin-section h2{font-size:1.5rem;font-weight:700;margin-bottom:1.5rem;color:var(--admin-text)}.card{padding:1.5rem}.admin-table{width:100%;border-collapse:collapse}.admin-table th{text-align:left;padding:1rem;color:var(--admin-text-muted);font-weight:600;border-bottom:1px solid var(--glass-border);font-size:.875rem;text-transform:uppercase;letter-spacing:.05em}.admin-table td{padding:1.25rem 1rem;border-bottom:1px solid rgba(255,255,255,.05)}.teacher-name{font-weight:600;color:var(--admin-text)}.count-badge{background:#3b82f61a;color:#60a5fa;padding:.25rem .75rem;border-radius:9999px;font-weight:500;font-size:.875rem}.level-pill{padding:.25rem .6rem;border-radius:6px;font-size:.7rem;font-weight:700;text-transform:uppercase;letter-spacing:.05em}.level-pill.high{background:#10b98133;color:#34d399}.level-pill.medium{background:#f59e0b33;color:#fbbf24}.level-pill.low{background:#6b728033;color:#9ca3af}.login-overlay{position:fixed;top:0;right:0;bottom:0;left:0;background:#fff;display:flex;align-items:center;justify-content:center;z-index:200}.login-card{width:100%;max-width:400px;padding:2.5rem;text-align:center}.login-card h2{margin-bottom:.5rem;color:var(--admin-text)}.login-card p{color:var(--admin-text-muted);margin-bottom:2rem;font-size:.9rem}.input-group{text-align:left;margin-bottom:1.25rem}.input-group label{display:block;font-size:.8125rem;font-weight:600;margin-bottom:.5rem;color:var(--admin-text-muted);text-transform:uppercase;letter-spacing:.025em}.input-group input{width:100%;background:#fff;border:1px solid var(--glass-border);border-radius:.75rem;padding:.85rem 1rem;color:var(--admin-text);outline:none;transition:all .2s;font-size:1rem}.input-group input:focus{border-color:var(--admin-accent);background:#fff;box-shadow:0 0 0 4px #089c3526}.primary-btn{width:100%;background:var(--admin-accent);color:#fff;border:none;padding:.85rem;border-radius:.75rem;font-weight:700;cursor:pointer;transition:all .2s;font-size:1rem;margin-top:1rem}.primary-btn:hover{background:var(--admin-accent-hover);transform:translateY(-1px);box-shadow:0 4px 12px #089c354d}.primary-btn:active{transform:translateY(0)}.logout-btn{background:transparent;border:1px solid var(--glass-border);color:var(--admin-text-muted);padding:.5rem 1.25rem;border-radius:.75rem;cursor:pointer;font-size:.875rem;font-weight:600;transition:all .2s}.logout-btn:hover{background:#f1f5f9;color:var(--admin-text);border-color:#cbd5e1}.admin-status{text-align:center;color:var(--admin-accent);font-weight:600;margin-bottom:1rem}.empty-msg{text-align:center;color:var(--admin-text-muted);padding:4rem 0!important}@media (max-width: 768px){.admin-nav{padding:0 1.25rem}.admin-content{padding:1.5rem 1.25rem}.admin-header h1{font-size:1.75rem}.stats-grid{grid-template-columns:1fr}}.local-tile video{transform:scaleX(-1)}.local-tile.screen-tile video{transform:none}#toolbar{display:flex;align-items:center;justify-content:center;gap:14px;padding:14px;background:var(--panel);border-top:1px solid var(--border)}.tool-btn{width:52px;height:52px;border-radius:50%;border:none;background:var(--panel3);color:var(--text);cursor:pointer;display:inline-flex;align-items:center;justify-content:center;transition:background .15s,transform .1s}.tool-btn:hover:not(:disabled){background:#444;transform:translateY(-1px)}.tool-btn:active:not(:disabled){transform:translateY(0)}.tool-btn:disabled{opacity:.4;cursor:not-allowed}.tool-btn.off{background:var(--red);color:#fff}.tool-btn.off:hover:not(:disabled){background:var(--red-hover)}.tool-btn.on{background:var(--blue);color:#fff}.tool-btn.on:hover:not(:disabled){background:var(--blue-hover)}.tool-btn.join{background:var(--green);color:#fff}.tool-btn.join:hover:not(:disabled){background:var(--green-hover)}.tool-btn.leave{background:var(--red);color:#fff}.tool-btn.leave:hover:not(:disabled){background:var(--red-hover)}@media (max-width: 900px){header{padding:10px 12px;gap:8px}.header-right .timer,.header-right #countInfo,.header-right #whoami,.header-right .dot-sep{display:none}.header-right .timer{display:inline}#videosWrap{padding:10px;gap:8px}#stage .tile{min-width:0}#stage:empty:before{font-size:13px;text-align:center;padding:0 16px}#thumbs .tile{flex:0 0 220px;height:130px}.mobile-only,.sidebar-close{display:inline-flex}#sidebar{position:fixed;top:0;right:0;bottom:0;width:88%;max-width:380px;min-width:0;border-left:1px solid var(--border);box-shadow:-8px 0 24px #00000059;transform:translate(100%);transition:transform .25s ease;z-index:50}body.panel-open #sidebar{transform:translate(0)}body.panel-open #sidebarBackdrop{display:block;position:fixed;top:0;right:0;bottom:0;left:0;background:#00000073;z-index:40}#toolbar{gap:10px;padding:10px;padding-bottom:max(10px,env(safe-area-inset-bottom))}.tool-btn{width:48px;height:48px}}@media (max-width: 640px){.brand-logo{height:22px}.header-divider{display:none}.role-badge{padding:2px 7px;font-size:10px}}@media (max-width: 640px){header{padding:8px 12px}.course-title{font-size:14px}.header-right{font-size:12px;gap:6px}#videosWrap{padding:8px;gap:6px}#stage{gap:6px}#stage .tile{flex:1 1 100%}#thumbs .tile{flex:0 0 160px;height:95px}#messages{padding:10px;gap:8px}.msg{padding:8px 12px;max-width:85%}#chatInput{padding:8px;padding-bottom:max(8px,env(safe-area-inset-bottom))}#chatInput input{font-size:16px;padding:10px 14px}#chatInput button{width:40px;height:40px}.tile{border-radius:10px}.badge{left:8px;bottom:8px;font-size:11px;padding:3px 8px}#toolbar{gap:6px;padding:8px}.tool-btn{width:44px;height:44px}.tool-btn svg{width:20px;height:20px}}@supports (padding: max(0px)){@media (max-width: 900px){header{padding-top:max(10px,env(safe-area-inset-top));padding-left:max(12px,env(safe-area-inset-left));padding-right:max(12px,env(safe-area-inset-right))}#chatInput{padding-bottom:max(8px,env(safe-area-inset-bottom))}}}.timer{font-variant-numeric:tabular-nums;font-weight:600;color:var(--text)}.msg a{color:var(--blue);text-decoration:underline;word-break:break-all}.msg a:hover{color:var(--blue-hover)}#lessonEndedOverlay{position:fixed;top:0;right:0;bottom:0;left:0;z-index:2000;display:flex;align-items:center;justify-content:center}.lesson-ended-backdrop{position:absolute;top:0;right:0;bottom:0;left:0;background:#0f172a80;-webkit-backdrop-filter:blur(2px);backdrop-filter:blur(2px)}.lesson-ended-card{position:relative;background:var(--panel, #ffffff);border:1px solid var(--border, #e2e8f0);border-radius:12px;padding:24px;width:100%;max-width:360px;margin:0 16px;box-shadow:0 8px 24px #0000004d}.lesson-ended-card h2{margin:0 0 8px;font-size:18px;font-weight:600;color:var(--text)}.lesson-ended-card p{margin:0 0 20px;font-size:14px;color:var(--muted)}.lesson-ended-actions{display:flex;gap:8px;justify-content:flex-end}.le-btn-primary{background:var(--green, #00a76f);color:#fff;padding:8px 16px;border-radius:8px;border:none;font-weight:600;font-size:14px;cursor:pointer}.le-btn-primary:hover{background:var(--green-hover, #00955f)}.le-btn-secondary{background:transparent;color:var(--muted);padding:8px 16px;border-radius:8px;border:1px solid var(--border);font-weight:500;font-size:14px;cursor:pointer}.le-btn-secondary:hover{background:var(--panel2)}.quick-page{min-height:100vh;display:flex;align-items:center;justify-content:center;padding:16px;background:#0f172a}.quick-card{width:100%;max-width:420px;background:#1e293b;border:1px solid #334155;border-radius:16px;padding:32px;box-shadow:0 20px 50px #0006}.quick-title{margin:0 0 6px;color:#f1f5f9;font-size:24px;font-weight:700}.quick-sub{margin:0 0 20px;color:#94a3b8;font-size:14px}.quick-label{display:block;margin-top:12px;margin-bottom:6px;color:#cbd5e1;font-size:12px;font-weight:600;text-transform:uppercase;letter-spacing:.05em}.quick-input{width:100%;padding:10px 12px;background:#0f172a;border:1px solid #475569;border-radius:8px;color:#f1f5f9;font-size:14px;outline:none;box-sizing:border-box}.quick-input:focus{border-color:#6366f1;box-shadow:0 0 0 3px #6366f133}.quick-input-readonly{background:#0a1424;color:#94a3b8;font-family:monospace}.quick-btn-primary{width:100%;margin-top:20px;padding:12px;background:#6366f1;border:none;border-radius:8px;color:#fff;font-size:15px;font-weight:600;cursor:pointer;transition:background .15s}.quick-btn-primary:hover{background:#4f46e5}.quick-btn-secondary{padding:6px 12px;background:#334155;border:1px solid #475569;border-radius:6px;color:#f1f5f9;font-size:12px;cursor:pointer}.quick-btn-secondary:hover{background:#475569}.quick-error{margin-top:12px;padding:8px 12px;background:#7f1d1d;border-radius:6px;color:#fee2e2;font-size:13px}.quick-share{margin-top:20px;padding-top:16px;border-top:1px solid #334155}.quick-hint{margin-top:8px;color:#64748b;font-size:12px}