/* educators/pdf-board.css - styles for the teaching workspace (Whiteboard / PDF / Photo) and the 4-mode switch
   v4 (3 Nov 2026): sliding segmented switch, long scrolling board, Hand cursor, eraser ring, delete menu,
   inline text box, prev/next with labels + disabled state, full-screen button. */
.ed-mode{display:flex;align-items:center;gap:12px;padding:8px 14px;background:linear-gradient(135deg,#0c1430,#16224f);color:#e6ebfa}
.ed-mode .seg{--i:0;--n:4;position:relative;display:inline-grid;grid-auto-flow:column;grid-auto-columns:1fr;flex:none;padding:3px;border-radius:999px;background:rgba(255,255,255,.08);box-shadow:inset 0 0 0 1px rgba(255,255,255,.1);isolation:isolate}
.ed-mode .seg::before{content:"";position:absolute;top:3px;bottom:3px;left:3px;width:calc((100% - 6px)/var(--n));border-radius:999px;background:linear-gradient(135deg,#f6dfae,#e9bd6a);box-shadow:0 2px 8px rgba(0,0,0,.25);transform:translateX(calc(var(--i)*100%));transition:transform .28s cubic-bezier(.4,0,.2,1);z-index:-1}
.ed-mode .seg button{min-width:0;border:0;background:none;color:#e6ebfa;font:600 13px system-ui,-apple-system,"Segoe UI",Roboto,sans-serif;padding:7px 16px;border-radius:999px;cursor:pointer;white-space:nowrap;transition:color .2s;text-align:center}
.ed-mode .seg button.on{color:#22190a}
.ed-mode .seg button:not(.on):hover{color:#fff}
.ed-mode .seg button:focus-visible{outline:2px solid #e9bd6a;outline-offset:2px}
.ed-mode small{font:500 12px system-ui,sans-serif;color:#aebbe0;margin-left:6px}
.ed-mode .ed-mode-r{margin-left:auto;display:flex;gap:6px;align-items:center}
.ed-mode .ed-mb{display:none;border:1px solid rgba(255,255,255,.25);background:rgba(255,255,255,.1);color:#fff;border-radius:10px;height:34px;padding:0 10px;font:600 12px system-ui,sans-serif;cursor:pointer;align-items:center;gap:6px}
.ed-max .ed-mode .ed-mb{display:inline-flex}
#edPdf[hidden]{display:none!important}
#edPdf{display:block;background:linear-gradient(160deg,#f4f7ff 0%,#eef2fb 55%,#f7f4ee 100%);overflow:hidden;min-height:340px}
.pb{height:100%;display:flex;flex-direction:column;min-height:0;font-family:system-ui,-apple-system,"Segoe UI",Roboto,"Noto Sans",sans-serif;color:#1d2440;position:relative}
.pb canvas{display:block;touch-action:none}
.pb-top{display:flex;align-items:center;gap:10px;padding:10px 14px 8px;flex:none}
.pb-file{display:flex;align-items:center;gap:8px;min-width:0;flex:1}
.pb-name{font:500 13px system-ui,sans-serif;color:#5f6f87;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;min-width:0}
.pb-b{display:inline-flex;align-items:center;justify-content:center;gap:6px;min-width:38px;height:38px;padding:0 9px;border-radius:12px;border:1px solid rgba(20,40,90,.12);background:#fff;color:#1d2440;cursor:pointer;box-shadow:0 1px 2px rgba(20,40,90,.05);font:600 13px system-ui,sans-serif;flex:none}
.pb-b:hover{background:#f3f6ff}.pb-b.on{background:#1b2a5e;color:#fff;border-color:#1b2a5e}
.pb-b:disabled{opacity:.38;cursor:not-allowed;box-shadow:none}.pb-b:disabled:hover{background:#fff}
.pb-b:focus-visible{outline:2px solid #2f5fd0;outline-offset:2px}
.pb-txt span{white-space:nowrap}
.pb-tabs{display:none;gap:4px}.pb-tabs button{border:1px solid rgba(20,40,90,.14);background:#fff;border-radius:999px;padding:7px 16px;font:600 13px system-ui,sans-serif;cursor:pointer}.pb-tabs button.on{background:#1b2a5e;color:#fff}
.pb-panes{flex:1;min-height:0;display:grid;grid-template-columns:minmax(0,1fr) 14px minmax(0,1fr);gap:0;padding:0 14px 8px}
.pb-pane{display:flex;flex-direction:column;min-height:0;min-width:0;background:#fff;border-radius:18px;border:1px solid rgba(20,40,90,.08);box-shadow:0 1px 2px rgba(20,40,90,.04),0 14px 34px rgba(20,40,90,.08);overflow:hidden}
.pb-ph{display:flex;align-items:center;gap:8px;padding:8px 10px;border-bottom:1px solid rgba(20,40,90,.08);flex:none;background:#fbfcff}
.pb-ph .pb-b{height:34px;min-width:34px}.pb-sp{flex:1}.pb-sm{font:500 12px system-ui,sans-serif;color:#5f6f87}
/* page navigation: Prev | 1 / 12 | Next (BUG-11) */
.pb-nav{display:inline-flex;align-items:center;gap:4px;padding:2px;border-radius:12px;background:#eef2fb}
.pb-nav .pb-b{border-color:transparent;background:transparent;box-shadow:none;height:30px}.pb-nav .pb-b:hover:not(:disabled){background:#fff}
.pb-nav .pb-b[data-k=prev] span{order:1}.pb-nav .pb-b[data-k=prev] svg{order:0}
.pb-pg{display:inline-flex;align-items:center;gap:4px;font:600 13px system-ui,sans-serif;padding:0 4px}.pb-pg input{width:40px;height:28px;text-align:center;border:1px solid rgba(20,40,90,.14);border-radius:8px;font:600 13px system-ui,sans-serif;background:#fff}
.pb-pg input:disabled{background:transparent;border-color:transparent}.pb-of{color:#8a97b3}
.pb-zl{font:600 12px system-ui,sans-serif;min-width:42px;text-align:center;color:#5f6f87}
.pb-stage{flex:1;min-height:0;overflow:auto;background:#e9edf6;position:relative;scrollbar-width:thin;overscroll-behavior:contain}
.pb-stage.drag{outline:3px dashed #2f5fd0;outline-offset:-8px}
.pb-bs{background:#fff;background-image:radial-gradient(rgba(20,40,90,.16) 1px,transparent 1px);background-size:22px 22px;overflow:auto}
.pb-bs canvas{background:transparent}
.pb-page{position:relative;margin:12px auto;width:max-content;box-shadow:0 6px 24px rgba(20,40,90,.18);background:#fff}
.pb-page[hidden]{display:none}.pb-ov{position:absolute;left:0;top:0}
/* cursors follow the tool (BUG-07 / BUG-08) */
.pb[data-tool=pen] .pb-ov,.pb[data-tool=pen] .pb-bs canvas{cursor:url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='26' height='26' viewBox='0 0 24 24'><path d='M16.4 3.6a2.3 2.3 0 0 1 3.2 3.2L7.6 18.8 3.5 20l1.2-4.1z' fill='%23fff' stroke='%231b2a5e' stroke-width='2' stroke-linejoin='round'/><path d='M12 20h9' stroke='%231b2a5e' stroke-width='2' stroke-linecap='round'/></svg>") 4 22, crosshair}.pb[data-tool=hi] .pb-ov,.pb[data-tool=hi] .pb-bs canvas{cursor:url("data:image/svg+xml;utf8,<svg xmlns='http://www.w3.org/2000/svg' width='26' height='26' viewBox='0 0 24 24'><path d='M9 11l-6 6v3h9l3-3' fill='%23ffe066' stroke='%231b2a5e' stroke-width='2' stroke-linejoin='round'/><path d='M22 12l-4.6 4.6a2 2 0 0 1-2.8 0l-5.2-5.2a2 2 0 0 1 0-2.8L14 4' fill='%23fff' stroke='%231b2a5e' stroke-width='2' stroke-linejoin='round'/></svg>") 3 22, crosshair}.pb[data-tool=line] canvas,.pb[data-tool=rect] canvas,.pb[data-tool=ell] canvas{cursor:crosshair}
.pb[data-tool=text] canvas{cursor:text}
.pb[data-tool=erase] canvas{cursor:var(--er-cur,cell)}
.pb[data-tool=pan] canvas{touch-action:pan-x pan-y pinch-zoom;cursor:grab}
.pb[data-tool=pan] .pb-stage{cursor:grab}.pb-stage.grab,.pb-stage.grab canvas{cursor:grabbing!important}
.pb-drop{height:100%;min-height:240px;display:flex;flex-direction:column;align-items:center;justify-content:center;gap:8px;text-align:center;padding:20px}
.pb-drop[hidden]{display:none}.pb-dt{font:700 22px Georgia,"Times New Roman",serif;color:#1b2a5e}.pb-drop p{margin:0;color:#5f6f87;font-size:14px}.pb-sm{font-size:12px}
.pb-pri{border:0;border-radius:12px;padding:11px 22px;background:#1b2a5e;color:#fff;font:700 14px system-ui,sans-serif;cursor:pointer}
.pb-sec{border:1px solid rgba(20,40,90,.18);border-radius:12px;padding:11px 18px;background:#fff;color:#1b2a5e;font:700 14px system-ui,sans-serif;cursor:pointer}
.pb-tools{flex:none;display:flex;align-items:center;justify-content:center;flex-wrap:nowrap;gap:6px;padding:8px 14px calc(8px + env(safe-area-inset-bottom,0px));overflow-x:auto;scrollbar-width:none;background:rgba(255,255,255,.94);border-top:1px solid rgba(20,40,90,.1);box-shadow:0 -10px 30px rgba(20,40,90,.08)}
.pb-tools::-webkit-scrollbar{display:none}
.pb-d{width:1px;height:26px;background:rgba(20,40,90,.14);margin:0 4px;flex:none}
.pb-col,.pb-sz{display:inline-flex;gap:6px;align-items:center;flex:none}
.pb-sw{width:24px;height:24px;border-radius:50%;border:2px solid #fff;background:var(--c);box-shadow:0 0 0 1px rgba(20,40,90,.25);cursor:pointer;padding:0}.pb-sw.on{box-shadow:0 0 0 2px #1b2a5e}
.pb-sd{width:30px;height:30px;border-radius:10px;border:1px solid rgba(20,40,90,.12);background:#fff;display:grid;place-items:center;cursor:pointer;padding:0}.pb-sd i{display:block;border-radius:50%;background:#1d2440}.pb-sd.on{background:#1b2a5e}.pb-sd.on i{background:#fff}
.pb-msg{position:absolute;left:50%;bottom:74px;transform:translateX(-50%);max-width:min(92%,560px);background:#1b2a5e;color:#fff;padding:9px 16px;border-radius:12px;font:600 13px system-ui,sans-serif;box-shadow:0 10px 28px rgba(0,0,0,.25);opacity:0;pointer-events:none;transition:opacity .2s;z-index:6}
.pb-msg.on{opacity:1}.pb-msg.bad{background:#b3261e}
/* delete menu sits ABOVE the footer, inside the workspace, never a native dialog (BUG-03 / BUG-06) */
.pb-del{position:absolute;right:14px;bottom:68px;z-index:7;width:min(320px,calc(100% - 28px));background:#fff;border-radius:16px;border:1px solid rgba(20,40,90,.12);box-shadow:0 18px 50px rgba(20,40,90,.22);padding:8px}
.pb-del[hidden]{display:none}
.pb-del-h{font:700 12px system-ui,sans-serif;letter-spacing:.08em;text-transform:uppercase;color:#5f6f87;padding:6px 10px 8px}
.pb-del-i{display:block;width:100%;text-align:left;border:0;border-radius:10px;background:none;padding:10px 12px;font:600 14px system-ui,sans-serif;color:#1d2440;cursor:pointer}
.pb-del-i:hover,.pb-del-i:focus-visible{background:#eef3fd;outline:none}
.pb-del-i.bad{color:#b3261e}.pb-del-i.ask{background:#fff1f0;color:#b3261e}
.pb-del-n{font:500 11px system-ui,sans-serif;color:#8a97b3;padding:6px 10px 4px}
/* inline text box */
.pb-tb{position:absolute;z-index:8;background:#fff;border:1px solid rgba(20,40,90,.18);border-radius:12px;box-shadow:0 12px 32px rgba(20,40,90,.2);padding:8px;min-width:220px}
.pb-tb textarea{display:block;width:100%;min-width:200px;border:1px solid rgba(20,40,90,.14);border-radius:8px;padding:6px 8px;resize:both;background:#fff}
.pb-tb-b{display:flex;gap:6px;margin-top:6px;align-items:center}.pb-tb-b .pb-pri{padding:7px 14px;font-size:13px}
.pb-modal{position:fixed;inset:0;z-index:100000;background:rgba(10,18,45,.55);display:grid;place-items:center;padding:16px}
.pb-card{width:min(520px,100%);max-height:86vh;overflow:auto;background:#fff;border-radius:20px;padding:22px;box-shadow:0 30px 80px rgba(0,0,0,.4);font-family:system-ui,sans-serif;color:#1d2440}
.pb-card h3{margin:0 0 14px;font:700 20px Georgia,serif;color:#1b2a5e}.pb-row{display:flex;gap:10px;flex-wrap:wrap;justify-content:center}
#odList{margin-top:14px;font-size:14px;color:#5f6f87}.pb-li{display:block;width:100%;text-align:left;padding:10px 12px;margin:0 0 6px;border:1px solid rgba(20,40,90,.12);border-radius:10px;background:#fbfcff;color:#1d2440;font:600 13px system-ui,sans-serif;cursor:pointer}.pb-li:hover{background:#eef3fd}
.pb-x{margin-top:16px;border:0;background:none;color:#5f6f87;font:600 13px system-ui,sans-serif;cursor:pointer}
/* whiteboard-only mode: no document pane, no show/hide or tabs */
.pb[data-mode=wb] .pb-show,.pb[data-mode=wb] .pb-tabs,.pb[data-mode=wb] .pb-pdf,.pb[data-mode=wb] .pb-split,.pb[data-mode=wb] #pbOpen,.pb[data-mode=wb] #pbOpenImg{display:none!important}
.pb[data-mode=wb] .pb-panes{grid-template-columns:minmax(0,1fr)!important}
.pb[data-mode=photo] #pbOpen,.pb[data-mode=pdf] #pbOpenImg{display:none}
@media (max-width:899px){
  .pb-tabs{display:flex}.pb-panes{grid-template-columns:minmax(0,1fr)}
  .pb[data-pane=pdf] .pb-board{display:none}.pb[data-pane=board] .pb-pdf{display:none}
  .pb-txt span{display:none}.pb-name{display:none}.pb-panes{padding:0 8px 6px}.pb-top{padding:8px 8px 6px}
  .pb-tools{justify-content:flex-start;padding-left:8px;padding-right:8px}
  .ed-mode small{display:none}
  .pb-nav .pb-b span{display:none}
}
.pb-split{position:relative;cursor:col-resize;touch-action:none;display:flex;align-items:center;justify-content:center;outline:none;user-select:none}
.pb-split::before{content:"";position:absolute;inset:0 -6px}
.pb-split i{display:block;width:4px;height:0;border-radius:4px;background:rgba(27,42,94,.0);transition:background .15s,height .15s}
.pb-split:hover i,.pb-split:focus-visible i,.pb-split.drag i{background:rgba(27,42,94,.5);height:80px}
.pb-split.drag i{background:#2f5fd0}
.pb-show{display:flex;gap:4px;flex:none}
.pb-show button{border:1px solid rgba(20,40,90,.14);background:#fff;border-radius:999px;padding:6px 14px;font:700 12px system-ui,sans-serif;color:#5f6f87;cursor:pointer;position:relative;padding-left:26px}
.pb-show button::before{content:"";position:absolute;left:9px;top:50%;width:10px;height:10px;margin-top:-5px;border-radius:50%;border:2px solid #b8c3da;background:#fff}
.pb-show button.on{background:#1b2a5e;color:#fff;border-color:#1b2a5e}.pb-show button.on::before{background:#e9bd6a;border-color:#e9bd6a}
@media (min-width:900px){
  .pb[data-show=pdf] .pb-board,.pb[data-show=pdf] .pb-split{display:none}
  .pb[data-show=board] .pb-pdf,.pb[data-show=board] .pb-split{display:none}
}
@media (max-width:899px){.pb-split,.pb-show{display:none}.pb-panes{gap:0}}
/* touch targets + phone ordering */
@media (max-width:899px),(pointer:coarse){
  .pb-b{min-width:44px;height:44px}
  .pb-ph .pb-b{min-width:40px;height:40px}.pb-nav .pb-b{height:36px;min-width:40px}
  .pb-sw{width:34px;height:34px;border-width:3px}
  .pb-sd{width:42px;height:42px}
  .pb-pg input{height:36px;width:44px}
  .pb-tabs button{min-height:42px;padding:8px 18px}
}
@media (max-width:899px){
  .pb-d{display:none}
  #pbTools [data-k=pan]{order:1}#pbTools [data-k=pen]{order:2}#pbTools [data-k=hi]{order:3}#pbTools [data-k=erase]{order:4}
  #pbTools [data-k=undo]{order:5}#pbTools [data-k=redo]{order:6}
  #pbTools [data-k=text]{order:7}#pbTools [data-k=line]{order:8}#pbTools [data-k=rect]{order:9}#pbTools [data-k=ell]{order:10}
  #pbTools .pb-col{order:11;padding:0 6px}#pbTools .pb-sz{order:12;padding:0 6px}#pbTools [data-k=clear]{order:13}
  .pb-tools{background:linear-gradient(to right,#fff 30%,rgba(255,255,255,0)),linear-gradient(to right,rgba(255,255,255,0),#fff 70%) 100% 0,radial-gradient(farthest-side at 0 50%,rgba(20,40,90,.22),transparent),radial-gradient(farthest-side at 100% 50%,rgba(20,40,90,.22),transparent) 100% 0;background-repeat:no-repeat;background-color:#fff;background-size:40px 100%,40px 100%,14px 100%,14px 100%;background-attachment:local,local,scroll,scroll}
  .ed-mode .seg{width:100%}.ed-mode .seg button{padding:10px 2px;font-size:11.5px;overflow:hidden;text-overflow:ellipsis}
  .pb-del{right:8px;left:8px;width:auto}
}
@media (max-width:480px){
  .ed-mode .seg button{font-size:11px;padding:10px 1px}
  .pb-zl{display:none}
  .pb-ph{gap:4px;padding:6px 8px}
  .pb-ph .pb-sp{flex:1 1 0;min-width:0}
  .pb-ph .pb-txt span{display:none}
}
@media (prefers-reduced-motion:reduce){.pb-split i,.pb-msg,.ed-mode .seg::before{transition:none}}

/* pens-v8: tool option popovers */
.pb-pop{right:auto;left:14px}.pb-pop .pb-del-i.on{background:#1b2a5e;color:#fff}
.pb-esz{display:flex;align-items:center;gap:6px;padding:4px 10px 8px}.pb-esz button{flex:1;height:34px;border-radius:9px;border:1px solid rgba(20,40,90,.15);background:#fff;font:600 13px system-ui,sans-serif;color:#1d2440;cursor:pointer;touch-action:none}.pb-esz button.on{background:#1b2a5e;color:#fff;border-color:#1b2a5e}.pb-esz b{flex:1;text-align:center;font:600 13px system-ui,sans-serif}
.pb-pc{display:flex;gap:10px;padding:4px 10px 8px}.pb-pc .pb-sw{width:28px;height:28px}
@media (max-width:640px){.pb-pop{left:8px;right:8px}}

/* board-v12: Question-Bank-style footer — square bordered buttons, groups split by dividers, page counter, Export / Expand / Close */
.pb-tools{gap:8px;padding:10px 14px calc(10px + env(safe-area-inset-bottom,0px));background:#fff;border-top:1px solid #e3e9f2;box-shadow:0 -8px 24px rgba(20,40,90,.06)}
.pb-tools .pb-b{width:44px;height:44px;min-width:44px;border-radius:10px;border:1px solid #d9e0ee;background:#fff;color:#1d2440;box-shadow:none}
.pb-tools .pb-b.pb-txt{width:auto;padding:0 14px;font:600 14px system-ui,sans-serif}.pb-tools .pb-b.pb-txt span{display:inline}
.pb-tools .pb-b:hover{background:#f3f6ff;border-color:#c5d0e6}.pb-tools .pb-b.on{background:#1b2a5e;border-color:#1b2a5e;color:#fff}
.pb-tools .pb-b:disabled{opacity:.35;cursor:default;background:#fff}
.pb-tools .pb-d{height:30px;margin:0 6px;background:#d9e0ee}
.pb-tools .pb-pg{display:inline-flex;align-items:center;gap:4px;height:44px;padding:0 12px;border:1px solid #d9e0ee;border-radius:10px;font:600 14px system-ui,sans-serif;color:#1d2440;flex:none}
.pb-tools .pb-pg input{width:44px;border:0;outline:0;text-align:center;font:inherit;background:transparent}.pb-tools .pb-of{color:#8a97b3}
@media(max-width:640px){.pb-tools .pb-b.pb-txt span{display:none}.pb-tools .pb-b.pb-txt{padding:0}.pb-tools .pb-b{width:40px;min-width:40px;height:40px}.pb-tools .pb-pg{height:40px;padding:0 8px}}

/* owner 3 Nov: the Menu button is only needed in full screen, where the top menu is hidden */
#pbMenu{display:none}.ed-max #pbMenu{display:inline-flex}

/* 3 Nov 2026 owner: toolbar icons were cut off at the edges on laptop/desktop widths -> wrap to a second row instead of hidden scroll (phones keep swipe-scroll). */
@media (min-width:900px){.pb-tools{flex-wrap:wrap;justify-content:center;overflow-x:visible;row-gap:6px}}