:root{ --bg:#0B1030; --surface:#141B45; --surface2:#1C2560; --border:#2E3A7A; --ink:#F2F4FA; --dim:#B9C2D8; --faint:#8790B0;
    --gold:#C9A227; --green:#34D399; --red:#FF5A63; --blue:#7FA0E0;
    --font:'Be Vietnam Pro', Arial, sans-serif; --mono:'JetBrains Mono', ui-monospace, monospace; color-scheme:dark; }
  *{box-sizing:border-box}
  html,body{margin:0; height:100%; background:var(--bg); color:var(--ink); font-family:var(--font); overflow:hidden; -webkit-text-size-adjust:100%}
  #stage{position:absolute; left:var(--cx, 50%); top:var(--cy, 50%); width:1920px; height:1080px; transform:translate(-50%, -50%) scale(var(--k, .5)) var(--mag, translate(0px, 0px)); transform-origin:center; overflow:hidden; background:#fff;}
  .s{position:absolute; inset:0; opacity:0; visibility:hidden; transition:opacity .35s ease, visibility 0s .35s;}
  .s.on{opacity:1; visibility:visible; transition:opacity .35s ease;}
  .s.img img{width:100%; height:100%; object-fit:contain; display:block; background:#fff;}
  #top button[hidden], #pnote .qa[hidden]{display:none !important;}
  #dots{display:none !important;}
  #top, #nav{transition:opacity .4s;} body.idle:not(.gp-presenter) #top, body.idle:not(.gp-presenter) #nav{opacity:0; pointer-events:none;} body.idle:not(.gp-presenter){cursor:none;}
  #home{font:600 12px var(--mono); color:var(--dim); background:rgba(18,26,46,.85); border:1px solid var(--border); border-radius:999px; padding:7px 12px; text-decoration:none;}
  /* chrome outside the stage */
  #top{position:fixed; z-index:40; top:max(10px, env(safe-area-inset-top)); right:max(12px, env(safe-area-inset-right)); display:flex; gap:8px; align-items:center;}
  #top button, #top span{font:600 12px var(--mono); color:var(--dim); background:rgba(18,26,46,.85); border:1px solid var(--border); border-radius:999px; padding:7px 12px; cursor:pointer;}
  #top span{cursor:default}
  #nav{position:fixed; z-index:40; left:0; right:0; bottom:max(12px, env(safe-area-inset-bottom)); display:flex; justify-content:space-between; align-items:center; padding:0 max(14px, env(safe-area-inset-right)) 0 max(14px, env(safe-area-inset-left)); pointer-events:none;}
  #nav > *{pointer-events:auto;}
  /* ---- thanh công cụ chuẩn của SlideKit (chuyển từ bài b1 vào core: mọi bài dùng chung, sửa ở đây là mọi bài đổi theo) ---- */
  #top #bUser{order:99;}                                                   /* ảnh cá nhân ngoài cùng bên phải, sau nút toàn màn hình */
  #top #bSet{display:none !important;}                                     /* Cài đặt mở từ ảnh đại diện */
  .s::after{display:none !important;}                                      /* số slide trên trang bỏ đi, đã có số trang ở nút chọn slide */
  #top #btoc{position:fixed !important; right:calc(max(14px, env(safe-area-inset-right)) + 56px); bottom:max(17px, calc(env(safe-area-inset-bottom) + 5px));}
  #top #ctr{display:none !important;}                                      /* số trang gộp vào nút chọn slide: ≡ 6 / 38 ▾ */
  #toc{top:auto !important; bottom:calc(max(17px, env(safe-area-inset-bottom)) + 48px); right:calc(max(14px, env(safe-area-inset-right)) + 56px) !important; max-height:calc(100vh - var(--pnh, 0px) - 90px) !important;}
  #top #bnotes{display:none !important;}                                   /* nút N chỉ dành cho iPad, iPad có nút ghi chú riêng */
  #top{transition:opacity .35s ease;}
  html:fullscreen #top, body.gp-presenter #top{opacity:.22 !important; pointer-events:auto !important;}
  html:fullscreen #top:hover, html:fullscreen #top:focus-within, html:fullscreen #top:active, body.gp-presenter #top:hover, body.gp-presenter #top:focus-within, body.gp-presenter #top:active{opacity:1 !important;}
  #nav button{width:44px; height:44px; border-radius:50%; border:1px solid var(--border); background:rgba(18,26,46,.85); color:var(--ink); font-size:20px; cursor:pointer;}
  #dots{display:flex; gap:6px; flex-wrap:wrap; justify-content:center; max-width:70vw;} #dots i{width:8px; height:8px; border-radius:50%; background:var(--border); cursor:pointer;} #dots i.on{background:var(--gold); width:22px; border-radius:4px;}
  #upd{position:fixed; z-index:70; left:50%; top:max(14px, env(safe-area-inset-top)); transform:translateX(-50%); display:none; align-items:center; gap:12px; background:var(--gold); color:#0A0F1F; border:0; border-radius:999px; padding:12px 22px; font:800 16px var(--font); cursor:pointer; box-shadow:0 0 0 100vmax rgba(5,8,15,.72), 0 10px 40px rgba(0,0,0,.5); animation:updp 1.6s ease-in-out infinite;}
  #upd.on{display:flex;} @keyframes updp{50%{box-shadow:0 0 0 10px rgba(255,204,78,.25), 0 0 0 100vmax rgba(5,8,15,.72), 0 10px 40px rgba(0,0,0,.5);}}
  #notes{position:fixed; z-index:45; left:0; right:0; bottom:0; max-height:32vh; overflow:auto; background:#070B17; border-top:1px solid var(--border); padding:12px 20px 18px; display:none; font-size:17px; line-height:1.55; color:var(--dim);}
  body.shownotes #notes{display:block} #notes .hd{display:flex; gap:16px; font:12px var(--mono); color:var(--faint); margin-bottom:6px} #notes .hd b{color:var(--gold); font-size:15px}
  #notes ul{margin:0; padding-left:20px} #notes li{margin:3px 0} #notes li::marker{color:var(--gold)}
  #laser{position:fixed; z-index:50; width:18px; height:18px; margin:-9px 0 0 -9px; border-radius:50%; background:#FF3B3B; box-shadow:0 0 18px 6px rgba(255,59,59,.6); pointer-events:none; display:none;}
  body.laser #laser{display:block} body.laser, body.laser *{cursor:none !important}
  #turn{position:fixed; z-index:55; inset:0; display:none; flex-direction:column; align-items:center; justify-content:center; gap:16px; padding:24px; text-align:center; background:rgba(5,8,15,.94); color:var(--ink);}
  body.portrait #turn{display:flex;} #turn h2{font-size:24px;} #turn p{font-size:15px; color:var(--dim); line-height:1.5; max-width:34ch;}
  #turn button{font:800 17px var(--font); border-radius:999px; padding:12px 24px; cursor:pointer; border:1px solid var(--border); background:none; color:var(--dim);}
  /* ===== Graspable Presenting (port from Atlas Talk / Graspable Lecture): an iPad drives the projector; notes and tools on the hand-held only ===== */
  #gpBtn{position:relative;} #gpBtn .dot{position:absolute; top:4px; right:5px; width:6px; height:6px; border-radius:50%; display:none;}
  #gpBtn.on .dot{display:block; background:var(--gold);} #gpBtn.on.live .dot{background:var(--green);}
  #gpBtn svg{width:15px; height:15px; fill:none; stroke:currentColor; stroke-width:2; stroke-linecap:round; stroke-linejoin:round; vertical-align:-3px;}
  #rc{position:fixed; inset:0; z-index:90; background:rgba(5,8,18,.82); display:grid; place-items:center; padding:16px; touch-action:auto; -webkit-user-select:text; user-select:text;}
  #rc[hidden]{display:none;}
  #rc .box{width:min(560px,100%); max-height:100%; overflow:auto; background:var(--surface); border:1px solid var(--border); border-radius:16px; padding:20px 22px; position:relative;}
  #rc h3{margin:0 0 4px; font-size:19px; color:var(--gold);} #rc p{margin:6px 0; color:var(--dim); font-size:14px; line-height:1.5;}
  #rc .x{position:absolute; top:10px; right:12px; background:none; border:0; color:var(--faint); font-size:24px; cursor:pointer;}
  #rc .opt{display:block; width:100%; text-align:left; margin-top:12px; border:1px solid var(--border); background:#16224A; color:var(--ink); border-radius:12px; padding:12px 14px; font:inherit; font-size:15px; cursor:pointer;}
  #rc .opt b{color:var(--gold);} #rc .opt small{display:block; color:var(--faint); font-size:13px; margin-top:3px;}
  #rc .join{display:flex; gap:8px; margin-top:10px;}
  #rc input{flex:1; min-width:0; font:600 20px var(--mono); letter-spacing:.2em; text-transform:uppercase; background:var(--bg); color:var(--ink); border:1px solid var(--border); border-radius:10px; padding:8px 12px;}
  #rc .go{border:0; background:var(--gold); color:#0A0F1F; font-weight:700; border-radius:10px; padding:0 18px; cursor:pointer; font-size:15px;}
  #rc .pair{display:flex; gap:18px; align-items:center; margin-top:12px; flex-wrap:wrap;}
  #rc .qr{background:#fff; padding:8px; border-radius:10px; flex:none;} #rc .qr canvas{display:none !important;} #rc .qr img{display:block; width:168px; height:168px;}
  #rc .code{font:700 40px var(--mono); letter-spacing:.14em; color:var(--gold);} #rc .st{font-size:14px; color:var(--faint);}
  #rc .off{margin-top:14px; background:none; border:1px solid var(--red); color:var(--red); border-radius:999px; padding:7px 14px; cursor:pointer; font:inherit; font-size:13px;}
  body.gp-presenter #nav, body.gp-presenter #notes, body.gp-presenter #bnotes{display:none !important;}
  #pnote{position:fixed; z-index:30; left:0; right:0; bottom:0; display:none; gap:12px; background:#070B17; border-top:1px solid var(--border); color:var(--ink);
    padding:6px max(8px, env(safe-area-inset-right)) max(6px, env(safe-area-inset-bottom)) max(8px, env(safe-area-inset-left)); touch-action:manipulation;}
  body.gp-presenter #pnote{display:flex;}
  #pnote .mid{flex:1; min-width:0; display:flex; flex-direction:column;}
  #pnote .pv,#pnote .pn{flex:none; width:clamp(64px,11vw,120px); align-self:center; height:100%; max-height:150px; display:flex; align-items:center; justify-content:center; gap:6px;
    border:1px solid var(--border); background:var(--surface2); color:var(--ink); border-radius:14px; font:700 16px var(--font); cursor:pointer;}
  #pnote .pn{background:var(--gold); color:#0A0F1F; border-color:var(--gold);}
  #pnote .pv svg,#pnote .pn svg{width:22px; height:22px; stroke:currentColor; fill:none; stroke-width:2.6; stroke-linecap:round; stroke-linejoin:round;}
  #pnote .pv:active,#pnote .pn:active{transform:scale(.96);} #pnote [disabled]{opacity:.25; pointer-events:none;}
  body.pn-min #pnote .pv span, body.pn-min #pnote .pn span{display:none;}
  #pnote .hd{display:flex; align-items:center; gap:14px; font:12px var(--mono); color:var(--faint); white-space:nowrap; min-height:30px;}
  #pnote .hd b{color:var(--ink); font-weight:600;} #pnote .timer{color:var(--gold); font-size:15px; font-weight:700; cursor:pointer;}
  #pnote .nx{overflow:hidden; text-overflow:ellipsis; flex:1;} #pnote .conn.ok{color:var(--green);} #pnote .conn.no{color:var(--red);}
  #pnote .rl{border:0; background:var(--red); color:#fff; border-radius:999px; font:700 12px var(--font); padding:3px 10px; cursor:pointer;} #pnote .rl[hidden]{display:none;}
  #pnote .tg{border:1px solid var(--border); background:none; color:var(--dim); border-radius:999px; font:inherit; padding:2px 10px; cursor:pointer;}
  #pnote .qa{font:700 13px var(--font); background:transparent; color:var(--ink); border:1px solid rgba(255,204,78,.5); border-radius:999px; padding:4px 10px; cursor:pointer; white-space:nowrap;} #pnote .qa.on{background:var(--gold); color:#1B1206; border-color:var(--gold);}
  #pnote .tx details{margin:3px 0; border-bottom:1px solid rgba(147,160,192,.15); padding:3px 0;} #pnote .tx summary{color:var(--ink); font-weight:600; cursor:pointer;} #pnote .tx details p{margin:4px 0 6px 16px;}
  #pnote .tx{flex:1; overflow-y:auto; font-size:16px; line-height:1.5; color:var(--dim); padding-top:4px; -webkit-user-select:text; user-select:text; touch-action:pan-y;}
  #pnote .tx ul{margin:0; padding-left:20px;} #pnote .tx li{margin:2px 0;} #pnote .tx b{color:var(--gold);} #pnote .tx .none{color:var(--faint); font-style:italic;}
  body.pn-min #pnote .tx{display:none;}
  #pnote .grip{position:absolute; left:0; right:0; top:-14px; height:28px; cursor:ns-resize; touch-action:none; z-index:1;}
  #pnote .grip::before{content:''; position:absolute; left:50%; top:9px; width:64px; height:6px; margin-left:-32px; border-radius:3px; background:var(--border); box-shadow:0 0 0 3px #070B17;}
  #pnote .grip:hover::before, body.pn-drag #pnote .grip::before{background:var(--gold);}
  #pnote .ptools{display:flex; flex-direction:row; gap:6px; flex:none; position:relative;}
  #pnote .tl{width:34px; height:30px; border-radius:999px; border:1px solid var(--border); background:none; color:var(--dim); cursor:pointer; display:flex; align-items:center; justify-content:center; padding:0;}
  #pnote .tl svg{width:18px; height:18px; fill:none; stroke:currentColor; stroke-width:2; stroke-linecap:round; stroke-linejoin:round;}
  #pnote .tl.on{background:var(--gold); border-color:var(--gold); color:#0A0F1F;} #pnote .tl[data-k="laser"].on{background:#FF3B3B; border-color:#FF3B3B; color:#fff;}
  #pnote .psize{position:absolute; bottom:calc(100% + 14px); right:0; display:flex; align-items:center; gap:10px; background:var(--surface); border:1px solid var(--border); border-radius:12px; padding:8px 12px; white-space:nowrap; box-shadow:0 8px 24px rgba(0,0,0,.55); font:12px var(--font); color:var(--dim);}
  #pnote .psize[hidden]{display:none;} #pnote .psize input{width:clamp(120px,18vw,220px); accent-color:var(--gold);} #pnote .psize b{font:700 13px var(--mono); color:var(--gold); min-width:48px; text-align:right;}
  #fx{position:fixed; inset:0; z-index:28; pointer-events:none;}   /* under the presenter bar (30) */ #fx canvas{position:absolute; inset:0; width:100%; height:100%;} #fx .spot{position:absolute; inset:0; opacity:0; transition:opacity .2s;}
  #ptrin{position:fixed; left:0; right:0; top:0; bottom:var(--pnh, 0px); z-index:25; display:none; touch-action:none; cursor:crosshair;}
  body.ptr-on #ptrin{display:block;}
  #lens{position:fixed; z-index:29; border-radius:50%; overflow:hidden; background:#fff; border:5px solid #E9B949; box-shadow:0 10px 40px rgba(0,0,0,.45); pointer-events:none; transition:opacity .15s;} #lens > div{pointer-events:none;}

  #toc{position:fixed; z-index:45; top:calc(max(10px, env(safe-area-inset-top)) + 44px); right:max(12px, env(safe-area-inset-right)); width:min(460px, calc(100vw - 24px)); max-height:calc(100vh - var(--pnh, 0px) - 70px); overflow:auto; -webkit-overflow-scrolling:touch; background:rgba(14,20,52,.97); border:1px solid var(--border); border-radius:16px; padding:8px; box-shadow:0 18px 50px rgba(0,0,0,.5);}
  #toc[hidden]{display:none;} #toc button{display:flex; gap:12px; align-items:baseline; width:100%; text-align:left; font:500 15px/1.35 var(--font); color:var(--ink); background:none; border:0; border-radius:10px; padding:10px 12px; cursor:pointer;}
  #toc button:hover{background:var(--surface2);} #toc button i{font:700 13px var(--mono); font-style:normal; color:var(--faint); min-width:30px;} #toc button.on{background:var(--gold); color:#0A0F1F;} #toc button.on i{color:#0A0F1F;}
  #toc button.sec{font-weight:800; color:var(--gold); margin-top:6px; border-top:1px solid var(--border); border-radius:0 0 10px 10px;} #toc button.sec.on{color:#0A0F1F;} #toc button.brk{opacity:.6;}

.s.dkx{display:none !important}
.s.far{display:none !important}
body.editing #pnote{display:none !important}
.s.dkg{outline:8px solid #9097AD; outline-offset:-8px}
#dots i.dk{opacity:.4}
#toc button.dk{opacity:.62} #toc button.dk span{text-decoration:line-through} #toc button.dk i{color:#8D95C4} #toc button i.cn{cursor:pointer; border-radius:6px; padding:0 4px; margin:0 -4px; min-width:34px} #toc button i.cn:hover{background:rgba(201,162,39,.28)}

#skv{position:fixed; left:calc(max(14px, env(safe-area-inset-left)) + 52px); bottom:max(5px, env(safe-area-inset-bottom)); z-index:30; font:600 11px/1 var(--mono, ui-monospace, monospace); color:rgba(128,128,128,.62); letter-spacing:.02em; cursor:pointer; user-select:none; -webkit-user-select:none; padding:3px 4px}
#skv[hidden]{display:none} body.gp-presenter:not(.editing) #skv{display:none}
body.studio #skv{z-index:60} body.studio #skList{padding-bottom:30px}

body.editing #nav{display:none !important}