:root{
  --paper:#f7f4ee; --card:#ffffff; --ink:#221e19; --muted:#6e675c;
  --line:#e4ddd0; --accent:#2f5d50; --accent-soft:#e7efec; --accent2:#a4512c;
  --red:#b6402f; --red-soft:#f6e4e1; --amber:#c8930c; --amber-soft:#f8eed3;
  --green:#2e7d4f; --green-soft:#e2efe6; --blue:#31567f; --blue-soft:#e3ebf3;
  --radius:12px; --shadow:0 1px 3px rgba(40,32,20,.08),0 6px 18px rgba(40,32,20,.06);
  --serif:"Inter",system-ui,-apple-system,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
  --sans:"Inter",system-ui,-apple-system,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
}
*{box-sizing:border-box}
html,body{margin:0;padding:0}
body{background:var(--paper);color:var(--ink);font-family:var(--sans);font-size:15.5px;line-height:1.5}
.boot{padding:60px;text-align:center;color:var(--muted)}
h1,h2,h3,h4{font-family:var(--serif);font-weight:600;line-height:1.2;margin:0 0 .4em}
h1{font-size:26px}h2{font-size:21px}h3{font-size:17px}h4{font-size:15.5px}
p{margin:.4em 0}
a{color:var(--accent)}
button{font:inherit;cursor:pointer}
input,select,textarea{font:inherit;color:var(--ink);background:#fff;border:1px solid var(--line);border-radius:8px;padding:8px 10px;max-width:100%}
input:focus,select:focus,textarea:focus{outline:2px solid var(--accent-soft);border-color:var(--accent)}
textarea{width:100%;min-height:70px;resize:vertical}
label{font-size:13px;color:var(--muted);display:block;margin:8px 0 3px}

/* layout */
.topbar{position:sticky;top:0;z-index:40;background:rgba(247,244,238,.94);backdrop-filter:blur(6px);border-bottom:1px solid var(--line);display:flex;align-items:center;gap:14px;padding:10px 18px;flex-wrap:wrap}
.topbar .brand{font-family:var(--serif);font-size:19px;font-weight:700;color:var(--accent);margin-right:6px}
.topbar nav{display:flex;gap:4px;flex-wrap:wrap}
.topbar .spacer{flex:1}
.navbtn{background:none;border:none;border-radius:8px;padding:7px 12px;color:var(--ink);position:relative}
.navbtn:hover{background:#eef3f1}
.navbtn.active{background:var(--accent);color:#fff}
.swapbtn{border:1px dashed var(--line);color:var(--muted);font-size:13px;margin-right:4px}
.swapbtn:hover{background:#eef3f1;color:var(--ink)}

/* side panel */
:root{--sidew:240px;--topoff:0px}
.nav-collapsed{--sidew:72px}
.sidenav{position:fixed;top:0;left:0;bottom:0;width:var(--sidew);z-index:25;background:#eef3f1;border-right:1px solid var(--line);display:flex;flex-direction:column;padding:12px 10px;overflow-y:auto;overflow-x:hidden;transition:width .18s}
.shell-nav~.wrap{margin-left:calc(var(--sidew) + max(0px, (100% - var(--sidew) - 1060px) / 2));margin-right:0;transition:margin-left .18s}
.sn-head{display:flex;align-items:center;gap:6px;padding:4px 6px 14px}
.sn-head .brand,.sn-mobilebar .brand{font-family:var(--serif);font-size:18px;font-weight:700;color:var(--accent);white-space:nowrap;overflow:hidden;text-overflow:ellipsis;flex:1}
.sn-collapse,.sn-closebtn,.sn-menubtn{border:none;background:none;border-radius:7px;padding:5px;color:var(--muted);display:flex;position:relative}
.sn-collapse:hover,.sn-closebtn:hover,.sn-menubtn:hover{background:#e4dccd;color:var(--ink)}
.sn-closebtn{display:none}
.sn-ico{width:20px;height:20px;flex:none;fill:none;stroke:currentColor;stroke-width:1.8;stroke-linecap:round;stroke-linejoin:round}
.sn-pages{flex:1}
.sn-group{margin-bottom:14px}
.sn-gtitle{font-size:12.5px;font-weight:600;color:var(--muted);padding:0 10px 3px;white-space:nowrap}
.sn-list{display:flex;flex-direction:column;gap:2px;min-height:6px;border-radius:9px}
.sn-item{display:flex;align-items:center;gap:11px;width:100%;border:none;background:none;border-radius:9px;padding:8px 10px;color:var(--ink);text-align:left;font-size:14.5px;position:relative;white-space:nowrap}
.sn-item:hover{background:#e4dccd}
.sn-item.active{background:#fff;color:var(--ink);font-weight:600;box-shadow:inset 0 0 0 1px var(--line)}
.sn-item.active .sn-ico{color:var(--accent);stroke-width:2.1}
.sn-lbl{flex:1;min-width:0;overflow:hidden;text-overflow:ellipsis}
.sn-badge{margin-left:0}
.sn-grip{display:none;color:var(--muted)}
.sn-tools{display:flex;justify-content:space-between;gap:6px;padding:6px 6px 10px}
.sn-link{border:none;background:none;color:var(--muted);font-size:12.5px;padding:3px 4px;border-radius:5px;text-decoration:underline;text-underline-offset:3px;text-decoration-color:#c9c0b0}
.sn-link:hover{color:var(--ink)}
.sn-reset{display:none}
.sn-foot{border-top:1px solid var(--line);padding-top:8px;display:flex;flex-direction:column;gap:2px}
.sn-swap{color:var(--muted);font-size:13.5px}
.editing .sn-reset{display:inline}
.editing .sn-tools .sn-link:first-child{color:#fff;background:var(--accent);text-decoration:none;padding:3px 12px}
.editing .sn-list{background:rgba(255,255,255,.45);outline:1px dashed #cfc6b5;padding:3px}
.editing .sn-item{cursor:grab;touch-action:none;user-select:none;-webkit-user-select:none}
.editing .sn-item.active{background:none;color:var(--ink);font-weight:700}
.editing .sn-grip{display:flex}
.sn-item.dragging{background:#fff;box-shadow:var(--shadow);cursor:grabbing}
/* collapsed to icons */
.nav-collapsed .sidenav{padding:12px 8px}
.nav-collapsed .sn-head{flex-direction:column;padding:4px 0 12px}
.nav-collapsed .sn-head .brand,.nav-collapsed .sn-lbl,.nav-collapsed .sn-tools,.nav-collapsed .sn-gtitle{display:none}
.nav-collapsed .sn-collapse{transform:rotate(180deg)}
.nav-collapsed .sn-group{border-top:1px solid var(--line);padding-top:8px}
.nav-collapsed .sn-group:first-child{border-top:none;padding-top:0}
.nav-collapsed .sn-item{justify-content:center;padding:10px 0}
.nav-collapsed .sn-badge{position:absolute;top:2px;right:2px;min-width:16px;font-size:10px;padding:0 4px}
.sn-mobilebar,.sn-backdrop{display:none}
.sn-dot{position:absolute;top:3px;right:3px;width:8px;height:8px;border-radius:50%;background:var(--accent2)}
@media(max-width:759px){
  :root,.nav-collapsed{--sidew:0px;--topoff:52px}
  .shell-nav~.wrap{margin-left:auto;margin-right:auto;padding-top:calc(52px + 18px)}
  .sn-mobilebar{display:flex;align-items:center;gap:8px;position:fixed;top:0;left:0;right:0;height:52px;z-index:24;background:rgba(247,244,238,.96);backdrop-filter:blur(6px);border-bottom:1px solid var(--line);padding:0 12px}
  .sidenav{width:270px;transform:translateX(-100%);transition:transform .2s;box-shadow:0 8px 28px rgba(30,25,18,.25)}
  .shell-nav.open .sidenav{transform:none}
  .shell-nav.open .sn-backdrop{display:block;position:fixed;inset:0;z-index:24;background:rgba(30,25,18,.4)}
  .sn-collapse{display:none}.sn-closebtn{display:flex}
  .nav-collapsed .sidenav{padding:12px 10px}
  .nav-collapsed .sn-head{flex-direction:row;padding:4px 6px 14px}
  .nav-collapsed .sn-head .brand,.nav-collapsed .sn-lbl,.nav-collapsed .sn-gtitle{display:block}
  .nav-collapsed .sn-tools{display:flex}
  .nav-collapsed .sn-item{justify-content:flex-start;padding:8px 10px}
  .nav-collapsed .sn-group{border-top:none;padding-top:0}
  .nav-collapsed .sn-badge{position:static}
}

/* calendar */
.calyear{display:grid;gap:12px;grid-template-columns:1fr}
@media(min-width:560px){.calyear{grid-template-columns:1fr 1fr}}
@media(min-width:860px){.calyear{grid-template-columns:repeat(3,1fr)}}
@media(min-width:1180px){.calyear{grid-template-columns:repeat(4,1fr)}}
.calmonth{background:var(--card);border:1px solid var(--line);border-radius:12px;padding:10px}
.calmonth.now{border-color:var(--accent)}
.calmname{font-family:var(--serif);font-weight:700;font-size:15px;margin-bottom:6px;color:var(--accent)}
.calgrid{display:grid;grid-template-columns:repeat(7,1fr);gap:2px}
.caldow{font-size:10px;color:var(--muted);text-align:center;padding-bottom:2px}
.calpad{height:34px}
.calday{height:34px;padding:0;border:1px solid transparent;border-radius:6px;background:none;color:var(--ink);font-size:12px;position:relative;cursor:pointer;display:flex;align-items:center;justify-content:center}
.calday:hover{background:#eef3f1;border-color:var(--line)}
.calday.has{background:var(--accent-soft);font-weight:700}
.calday.busy{background:#c9dcd4;font-weight:700}
.calday.packed{background:var(--accent);color:#fff;font-weight:700}
.calday.today{border-color:var(--accent);font-weight:700;box-shadow:inset 0 0 0 1px var(--accent)}
.caldot{position:absolute;bottom:1px;right:3px;font-size:8px;font-weight:700;line-height:1;color:var(--accent)}
.calflag{position:absolute;top:1px;right:3px;font-size:8px;line-height:1;color:var(--amber)}
.calday.packed .caldot,.calday.packed .calflag{color:#fff}
.calbar{display:flex;align-items:center;gap:10px;margin-bottom:12px;flex-wrap:wrap}
.calbar .yr{font-family:var(--serif);font-size:22px;font-weight:700;min-width:70px;text-align:center}
.callegend{font-size:12px;color:var(--muted)}
.calkey{display:flex;align-items:center;gap:6px;font-size:12px;color:var(--muted);margin-top:12px;flex-wrap:wrap}
.calkey i{display:inline-block;width:16px;height:16px;border-radius:4px;border:1px solid var(--line);vertical-align:-3px}
.dayrow{display:flex;gap:10px;align-items:flex-start;padding:8px 0;border-bottom:1px solid var(--line)}
.badge{display:inline-block;min-width:18px;padding:1px 5px;border-radius:9px;background:var(--accent2);color:#fff;font-size:11px;font-weight:700;text-align:center;margin-left:5px;vertical-align:top}
.wrap{max-width:1060px;margin:0 auto;padding:22px 18px 90px}
.grid{display:grid;gap:14px}
@media(min-width:760px){.grid.two{grid-template-columns:1fr 1fr}.grid.three{grid-template-columns:1fr 1fr 1fr}}

/* cards */
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);box-shadow:var(--shadow);padding:16px 18px;margin-bottom:14px}
.card.clickable:hover{border-color:var(--accent);cursor:pointer}
.card h3 .sub{font-family:var(--sans);font-weight:400;color:var(--muted);font-size:13px}
.rowline{display:flex;align-items:center;gap:10px;flex-wrap:wrap}
.rowline .grow{flex:1;min-width:120px}
.subtle{color:var(--muted);font-size:13px}
.tiny{font-size:12px;color:var(--muted)}
hr{border:none;border-top:1px solid var(--line);margin:12px 0}

/* buttons */
.btn{background:var(--accent);color:#fff;border:none;border-radius:9px;padding:8px 15px;font-weight:600}
.btn:hover{filter:brightness(1.08)}
.btn.secondary{background:#eef3f1;color:var(--ink)}
.btn.danger{background:var(--red)}
.btn.ghost{background:none;border:1px solid var(--line);color:var(--ink)}
.btn.small{padding:4px 10px;font-size:13px;border-radius:7px}
.btn:disabled{opacity:.5;cursor:not-allowed}
.btnrow{display:flex;gap:8px;flex-wrap:wrap;margin-top:10px}

/* pills & chips */
.pill{display:inline-block;padding:2px 10px;border-radius:20px;font-size:12px;font-weight:600}
button.pill{border:1px solid transparent;font-family:inherit;cursor:default}
button.pill.jump{cursor:pointer}
button.pill.jump:hover{filter:brightness(.94);border-color:currentColor}
button.pill:disabled{opacity:.5}
.topic.flash{animation:topicflash 1.6s ease-out}
@keyframes topicflash{0%,55%{background:var(--accent-soft)}100%{background:transparent}}
.ragnav{position:fixed;top:calc(var(--topoff) + 58px);right:14px;z-index:90;background:var(--ink);color:#fff;border-radius:10px;padding:5px 6px;box-shadow:var(--shadow);display:flex;align-items:center;gap:2px;font-size:13px}
.ragnav .lbl{padding:0 6px;font-weight:600;white-space:nowrap}
.ragnav button{background:none;border:none;color:#fff;font:inherit;font-size:17px;line-height:1;padding:3px 8px;border-radius:6px;cursor:pointer}
.ragnav button:hover{background:rgba(255,255,255,.18)}
.ragnav button.close{font-size:14px;opacity:.7;margin-left:2px}
.ragnav.red .lbl{color:#ffb4a6}
.ragnav.amber .lbl{color:#ffd98a}
.ragnav.green .lbl{color:#a9e3bf}
.pill.red{background:var(--red-soft);color:var(--red)}
.pill.amber{background:var(--amber-soft);color:#8a6606}
.pill.green{background:var(--green-soft);color:var(--green)}
.pill.blue{background:var(--blue-soft);color:var(--blue)}
.pill.grey{background:#eef3f1;color:var(--muted)}
.chip{display:inline-block;background:#eef3f1;border-radius:7px;padding:2px 8px;font-size:12px;margin:2px 3px 2px 0}

/* tracker */
.section-block{margin-bottom:10px}
.section-head{display:flex;align-items:center;gap:10px;background:#eef3f1;border-radius:9px;padding:9px 13px;cursor:pointer}
.section-head:hover{background:#e3ebe8}
.section-head .count{margin-left:auto;font-size:12.5px;color:var(--muted);white-space:nowrap}
.topic{display:flex;align-items:flex-start;gap:9px;padding:9px 6px;border-bottom:1px solid var(--line);flex-wrap:wrap}
.topic:last-child{border-bottom:none}
.topic .title{flex:1;min-width:200px}
.topic .title .code{font-weight:700;color:var(--accent)}
.tick{width:21px;height:21px;border-radius:6px;border:2px solid var(--line);display:inline-flex;align-items:center;justify-content:center;font-size:13px;color:#fff;flex-shrink:0;margin-top:1px}
.tick.on{background:var(--green);border-color:var(--green)}
.tick.btn-like{cursor:pointer}
.ragset{display:flex;gap:4px}
.ragdot{width:22px;height:22px;border-radius:50%;border:2px solid var(--line);background:#fff;padding:0}
.ragdot.red.on{background:var(--red);border-color:var(--red)}
.ragdot.amber.on{background:var(--amber);border-color:var(--amber)}
.ragdot.green.on{background:var(--green);border-color:var(--green)}
.ragdot:hover{transform:scale(1.12)}
.flagbtn{background:none;border:none;font-size:17px;opacity:.35;padding:0 3px}
.flagbtn.on{opacity:1}
.expander{width:100%;background:#f5f8f7;border-radius:8px;padding:10px 12px;margin-top:6px}
.commentrow{padding:6px 0;border-bottom:1px dashed var(--line);font-size:14px}
.commentrow:last-child{border-bottom:none}
.commentrow .who{font-weight:700;font-size:12.5px}
.commentrow .who.tutor{color:var(--accent2)}
.commentrow .who.student{color:var(--accent)}

/* progress ring-ish bar */
.tally{margin:6px 0}
.tallybar{height:9px;border-radius:5px;background:#e3ebe8;overflow:hidden}
.tallybar>div{height:100%;background:var(--accent);border-radius:5px;transition:width .3s}
.tallyline{display:flex;justify-content:space-between;font-size:12.5px;color:var(--muted);margin-top:3px}

/* lessons */
.lesson{border-left:4px solid var(--accent);padding-left:12px;margin:12px 0}
.lesson.past{border-left-color:#c9c0b0}
.lesson .when{font-weight:700;font-family:var(--serif)}
.hw{display:flex;align-items:flex-start;gap:8px;padding:4px 0}
.hw input[type=checkbox]{width:17px;height:17px;margin-top:2px}
.hw.done .txt{text-decoration:line-through;color:var(--muted)}

/* papers & sitting */
.pdfframe{width:100%;height:70vh;border:1px solid var(--line);border-radius:10px;background:#fff}
.sitting-layout{display:grid;gap:16px}
@media(min-width:980px){.sitting-layout{grid-template-columns:minmax(0,1.25fr) minmax(330px,1fr)}}
.answersheet{max-height:78vh;overflow-y:auto;padding-right:4px}
.partrow{border:1px solid var(--line);border-radius:10px;padding:10px 12px;margin-bottom:9px;background:#fff}
.partrow .plabel{font-weight:700;font-family:var(--serif)}
.partrow.correct{border-color:var(--green);background:var(--green-soft)}
.partrow.incorrect{border-color:var(--red);background:var(--red-soft)}
.partrow.pending{border-color:var(--amber);background:var(--amber-soft)}
.result-ico{font-weight:800;margin-left:6px}
.thumbs{display:flex;gap:6px;flex-wrap:wrap;margin-top:6px}
.thumbs img{height:64px;border-radius:6px;border:1px solid var(--line);cursor:pointer}
.timerbox{position:sticky;top:calc(var(--topoff) + 12px);z-index:30;background:var(--ink);color:#fff;border-radius:10px;padding:8px 14px;font-variant-numeric:tabular-nums;display:inline-block;font-weight:700;letter-spacing:.5px}
.timerbox.low{background:var(--red)}
.scoreband{background:var(--accent-soft);border:1px solid #cfdfd9;border-radius:10px;padding:10px 14px;margin:10px 0;font-weight:600}

/* toasts & modals */
#toasts{position:fixed;top:14px;right:14px;z-index:100;display:flex;flex-direction:column;gap:8px;max-width:330px}
.toast{background:var(--ink);color:#fff;border-radius:10px;padding:10px 14px;box-shadow:var(--shadow);display:flex;gap:10px;align-items:flex-start;font-size:14px}
.toast.warn{background:var(--accent2)}
.toast.error{background:var(--red)}
.toast .x{background:none;border:none;color:#fff;font-size:16px;padding:0;margin-left:auto}
.modal-back{position:fixed;inset:0;background:rgba(30,25,18,.55);z-index:90;display:flex;align-items:center;justify-content:center;padding:18px}
.modal{background:#fff;border-radius:14px;padding:22px;max-width:520px;width:100%;max-height:88vh;overflow-y:auto;box-shadow:0 18px 50px rgba(0,0,0,.3)}
.modal h2{margin-top:0}

/* auth */
.auth{max-width:400px;margin:9vh auto;background:#fff;border:1px solid var(--line);border-radius:14px;padding:28px;box-shadow:var(--shadow)}
.auth .brand{font-family:var(--serif);font-size:26px;color:var(--accent);font-weight:700;text-align:center;margin-bottom:14px}
.auth input{width:100%;margin-bottom:10px}
.auth .btn{width:100%}

/* roster */
.roster-card{display:flex;flex-direction:column;gap:6px}
.attn{color:var(--accent2);font-weight:700;font-size:13px}
.tabs{display:flex;gap:4px;flex-wrap:wrap;border-bottom:1px solid var(--line);margin-bottom:14px}
.tab{background:none;border:none;padding:8px 13px;border-radius:9px 9px 0 0;color:var(--muted);font-weight:600}
.tab.active{background:#fff;border:1px solid var(--line);border-bottom-color:#fff;color:var(--ink)}

/* queue */
.queue-item{border:1px solid var(--line);border-left:4px solid var(--amber);border-radius:10px;padding:12px 14px;margin-bottom:10px;background:#fff}
.answerbox{background:#f5f8f7;border-radius:8px;padding:8px 11px;margin:6px 0;font-size:14.5px;white-space:pre-wrap}

/* builder */
.qblock{border:1px solid var(--line);border-radius:10px;padding:11px 13px;margin-bottom:10px;background:#fff}
.partline{display:flex;gap:7px;align-items:center;flex-wrap:wrap;padding:6px 0;border-top:1px dashed var(--line)}
.partline input.short{width:64px}
.partline input.key{width:130px}
.partline select{width:130px}

.empty{color:var(--muted);text-align:center;padding:26px;font-style:italic}
.err{color:var(--red);font-size:13.5px;margin-top:6px}
img.full{max-width:100%;border-radius:8px}
.footer-note{color:var(--muted);font-size:12px;text-align:center;margin-top:30px}

/* ============ whiteboards ============ */
body.wb-open{overflow:hidden}
.wb-hubrow{padding:7px 0;border-bottom:1px solid var(--line)}
.wb{--wb-chrome:#f1f5f4;--wb-hover:#e6eeeb;--wb-on:#dde8e4;--wb-onb:#c3d3cd;position:fixed;inset:0;z-index:30;display:flex;flex-direction:column;background:var(--wb-chrome);color:var(--ink)}
.wb button{font:inherit;color:inherit}
.wb-ico{display:block;flex:none}

/* top row: back, title, tabs, people, status */
.wb-head{display:flex;align-items:flex-end;gap:6px;padding:6px 12px 0;min-height:42px}
.wb-head .spacer{flex:1}
.wb-back{display:flex;align-items:center;gap:2px;border:none;background:none;border-radius:6px;padding:5px 8px 5px 4px;margin-bottom:5px;font-size:14px}
.wb-back:hover{background:var(--wb-hover)}
.wb-back .wb-ico{width:18px;height:18px}
.wb-title{font-family:var(--serif);font-weight:700;font-size:16px;color:var(--accent);margin:0 10px 9px 4px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;max-width:240px}
.wb-tabs{display:flex;gap:2px}
.wb-tab{border:none;background:none;padding:6px 12px 9px;font-size:14.5px;position:relative;border-radius:6px 6px 0 0}
.wb-tab:hover{background:var(--wb-hover)}
.wb-tab.on{font-weight:600}
.wb-tab.on::after{content:"";position:absolute;left:12px;right:12px;bottom:3px;height:3px;border-radius:2px;background:var(--accent)}
.wb-presence{display:flex;gap:4px;align-items:center;margin-bottom:9px}
.wb-who{font-size:12px;padding:2px 9px;border-radius:12px;background:var(--blue-soft);color:var(--blue);font-weight:600;white-space:nowrap}
.wb-who.tutor{background:var(--accent-soft);color:var(--accent)}
.wb-who.away{opacity:.55}
.wb-status{font-size:12px;color:var(--muted);white-space:nowrap;margin:0 2px 10px 6px;display:flex;align-items:center;gap:5px}
.wb-status::before{content:"";width:8px;height:8px;border-radius:50%;background:#b8b1a3}
.wb-status.ok{color:var(--green)}.wb-status.ok::before{background:var(--green)}
.wb-status.off{color:var(--amber)}.wb-status.off::before{background:var(--amber)}

/* the ribbon */
.wb-ribbon{display:flex;align-items:center;margin:0 10px 8px;background:#fff;border-radius:10px;box-shadow:0 1px 2px rgba(40,32,20,.1),0 2px 8px rgba(40,32,20,.06);min-height:62px;padding:4px 8px;overflow-x:auto;overflow-y:hidden;scrollbar-width:thin}
.wb-pane{display:flex;align-items:center;gap:2px;flex:none}
.wb-sep{flex:none;width:1px;height:34px;background:#dbe4e1;margin:0 7px}
.wb-rb{flex:none;display:inline-flex;align-items:center;justify-content:center;gap:6px;min-width:42px;height:46px;padding:0 9px;border:1px solid transparent;border-radius:7px;background:none;font-size:14px;white-space:nowrap;touch-action:manipulation}
.wb-rb:hover:not(:disabled){background:var(--wb-hover)}
.wb-rb.on{background:var(--wb-on);border-color:var(--wb-onb)}
.wb-rb:disabled{opacity:.35;cursor:default}
.wb-rb.lbl{padding:0 11px 0 8px}
.wb-lbl{font-size:12px;color:var(--muted);margin:0 6px 0 4px;white-space:nowrap}
.wb-zoomlbl{min-width:56px;font-size:13px;font-weight:600}

/* pen tray */
.wb-tray{display:flex;align-items:flex-end;gap:1px;height:52px}
.wb-pen{flex:none;position:relative;width:40px;height:52px;padding:5px 0 0;border:1px solid transparent;border-radius:7px;background:none;display:flex;justify-content:center;align-items:flex-start;overflow:hidden;touch-action:manipulation}
.wb-pen svg{transition:transform .12s}
.wb-pen:hover{background:var(--wb-hover)}
.wb-pen:hover svg{transform:translateY(2px)}
.wb-pen.on{background:var(--wb-on);border-color:var(--wb-onb)}
.wb-pen.on svg{transform:translateY(4px)}
.wb-penchev{position:absolute;right:0;bottom:1px;width:13px;height:13px;color:var(--ink)}
.wb-penchev .wb-ico{width:13px;height:13px;stroke-width:2.4}
.wb-addpen{min-width:34px;height:40px;margin-bottom:5px;color:var(--green)}

/* insert / view extras */
.wb-dots{display:inline-flex;gap:5px;margin:0 6px 0 2px}
.wb-swatch{width:22px;height:22px;border-radius:50%;border:2px solid #fff;box-shadow:0 0 0 1px #c3d3cd;padding:0}
.wb-swatch.on{box-shadow:0 0 0 2px var(--ink)}
.wb-font{display:inline-flex;align-items:center;gap:2px;flex:none}
.wb-fontcombo{display:inline-flex;align-items:stretch;border:1px solid #c3d3cd;border-radius:4px;background:#fff;height:30px}
.wb-fontcombo:focus-within{border-color:var(--accent)}
.wb-fontinp{width:44px;border:none;border-radius:4px 0 0 4px;padding:2px 6px;font-size:14px;outline:none;background:none}
.wb-fontinp:focus{outline:none}
.wb-fontdrop{border:none;border-left:1px solid #dbe4e1;background:none;padding:0 3px;border-radius:0 4px 4px 0}
.wb-fontdrop:hover{background:var(--wb-hover)}
.wb-fontdrop .wb-ico{width:14px;height:14px}
.wb-fontstep{border:1px solid transparent;background:none;border-radius:5px;height:30px;min-width:30px;padding:0 4px;font-size:17px;font-weight:600;font-family:var(--serif)}
.wb-fontstep.small{font-size:13px}
.wb-fontstep sup{font-size:9px;margin-left:1px;font-family:var(--sans)}
.wb-fontstep:hover{background:var(--wb-hover)}
.wb-sizelist{display:flex;flex-direction:column;max-height:300px;overflow-y:auto;padding:4px 0}
.wb-sizelist button{border:none;background:none;text-align:left;padding:5px 16px;font-size:14px}
.wb-sizelist button:hover{background:#f2f6f5}
.wb-sizelist button.on{background:var(--accent-soft);font-weight:700}
.wb-bgtiles{display:inline-flex;gap:4px}
.wb-bgtile{display:flex;flex-direction:column;align-items:center;gap:2px;border:1px solid transparent;border-radius:7px;background:none;padding:4px 5px 2px;font-size:11px}
.wb-bgtile:hover:not(:disabled){background:var(--wb-hover)}
.wb-bgtile.on{background:var(--wb-on);border-color:var(--wb-onb)}
.wb-bgtile:disabled{cursor:default}
.wb-bgtile:disabled:not(.on){opacity:.45}
.wb-bgtile i{display:block;width:40px;height:28px;border:1px solid #c3d3cd;border-radius:4px;background-color:#fff}
.bg-squares{background-image:linear-gradient(to right,#c9d6e4 1px,transparent 1px),linear-gradient(to bottom,#c9d6e4 1px,transparent 1px);background-size:8px 8px}
.bg-graph{background-image:linear-gradient(to right,#9fb9d4 1px,transparent 1px),linear-gradient(to bottom,#9fb9d4 1px,transparent 1px),linear-gradient(to right,#e1e9f2 1px,transparent 1px),linear-gradient(to bottom,#e1e9f2 1px,transparent 1px);background-size:15px 15px,15px 15px,3px 3px,3px 3px}
.bg-dots{background-image:radial-gradient(circle,#98a4b3 1px,transparent 1.4px);background-size:6px 6px}
.bg-lined{background-image:linear-gradient(to bottom,#c4d4e8 1px,transparent 1px);background-size:100% 7px}
.wb-ctx{flex:none;display:flex;align-items:center;gap:2px;margin-left:auto;padding-left:10px;border-left:1px solid #dbe4e1}
.wb-ctxcol i{display:block;width:20px;height:20px;border-radius:50%;box-shadow:0 0 0 1px #c3d3cd}
.wb-ctxcol .wb-ico{width:14px;height:14px}

/* page list + board */
.wb-main{flex:1;display:flex;min-height:0}
.wb-pages{flex:none;width:210px;display:flex;flex-direction:column;margin:0 0 10px 10px;background:#fff;border-radius:10px;box-shadow:0 1px 2px rgba(40,32,20,.1);overflow:hidden}
.wb.nopages .wb-pages{display:none}
.wb-pages-head{display:flex;align-items:center;justify-content:space-between;padding:10px 10px 8px 14px;border-bottom:1px solid #e3ebe8}
.wb-pages-head b{font-size:14px}
.wb-addpage{display:flex;align-items:center;gap:3px;border:none;background:none;border-radius:6px;padding:4px 8px 4px 4px;font-size:13px;color:var(--accent);font-weight:600}
.wb-addpage:hover{background:var(--wb-hover)}
.wb-addpage .wb-ico{width:18px;height:18px}
.wb-pagelist{overflow-y:auto;padding:4px 0}
.wb-pagerow{display:flex;align-items:center;gap:4px;padding:8px 8px 8px 14px;font-size:14px;cursor:pointer;border-left:3px solid transparent}
.wb-pagerow:hover{background:#f2f6f5}
.wb-pagerow.on{background:var(--accent-soft);border-left-color:var(--accent);font-weight:600}
.wb-pagename{flex:1;min-width:0;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.wb-pagemore{border:none;background:none;border-radius:5px;padding:2px;color:var(--muted)}
.wb-pagemore:hover{background:#fff;color:var(--ink)}
.wb-pagemore .wb-ico{width:18px;height:18px}
.wb-stage{flex:1;position:relative;min-width:0;margin:0 10px 10px;border-radius:10px;overflow:hidden;box-shadow:0 1px 2px rgba(40,32,20,.1),0 2px 10px rgba(40,32,20,.05)}

/* full page view */
.wb-float{display:none;position:absolute;top:12px;left:50%;transform:translateX(-50%);z-index:5;align-items:flex-end;gap:2px;background:#fff;border:1px solid #cbd8d3;border-radius:10px;box-shadow:0 4px 18px rgba(40,32,20,.16);padding:4px 6px;max-width:calc(100% - 24px);overflow-x:auto}
.wb-float>.wb-rb{height:44px;margin-bottom:3px}
.wb-dot{flex:none;width:9px;height:9px;border-radius:50%;background:#b8b1a3;margin:0 8px 21px 6px}
.wb-dot.ok{background:var(--green)}.wb-dot.off{background:var(--amber)}
.wb.full .wb-head,.wb.full .wb-ribbon,.wb.full .wb-pages{display:none}
.wb.full .wb-float{display:flex}
.wb.full .wb-stage{margin:0;border-radius:0;box-shadow:none}

/* lasso + stylus settings */
.wb-lassoline{fill:rgba(47,93,80,.06);stroke:var(--accent);stroke-width:1.5;stroke-dasharray:6 4;vector-effect:non-scaling-stroke}
.wb-stylus{width:330px !important}
.wb-stylus-row{padding:6px 6px;border-radius:6px;margin:0 -6px}
.wb-stylus-row.hit{background:var(--amber-soft)}
.wb-stylus-lbl{font-size:13px;margin-bottom:4px}
.wb-seg{display:inline-flex;border:1px solid #cbd8d3;border-radius:7px;overflow:hidden}
.wb-seg button{border:none;background:#fff;padding:5px 10px;font-size:12.5px;font-weight:600}
.wb-seg button+button{border-left:1px solid #cbd8d3}
.wb-seg button.on{background:var(--accent);color:#fff}
.wb-stylus-status{margin-top:8px;font-size:12.5px;color:var(--muted);background:#f2f6f5;border-radius:6px;padding:7px 9px}
.wb-stylus-status.hit{color:var(--ink);background:var(--amber-soft)}

/* hover labels */
.wb-tip{position:fixed;z-index:70;pointer-events:none;background:#fff;color:var(--ink);border:1px solid #c3d3cd;border-radius:6px;box-shadow:0 4px 16px rgba(30,25,18,.18);padding:6px 10px;max-width:260px;font-size:13px;line-height:1.35}
.wb-tip b{display:block;font-weight:600}
.wb-tip span{display:block;color:var(--muted);font-size:12px;margin-top:1px}

/* drop-down menus (pen settings etc.) */
.wb-pop{position:fixed;z-index:60;min-width:90px;background:#fff;border:1px solid #c3d3cd;border-radius:6px;box-shadow:0 8px 28px rgba(30,25,18,.22);max-height:calc(100vh - 16px);overflow-y:auto;padding:2px 0}
.wb-pop-sec{padding:8px 12px 10px;border-bottom:1px solid #e3ebe8;width:226px}
.wb-pop-prev{display:block;margin:4px auto}
.wb-pop-h{font-size:14px;font-weight:700;margin:2px 0 8px}
.wb-thick{display:flex;align-items:center;justify-content:space-between}
.wb-thstep{border:none;background:none;border-radius:5px;padding:2px}
.wb-thstep .wb-ico{width:18px;height:18px}
.wb-thstep:hover:not(:disabled){background:var(--wb-hover)}
.wb-thstep:disabled{opacity:.3}
.wb-thdot{width:24px;height:24px;border-radius:50%;border:2px solid transparent;background:none;display:flex;align-items:center;justify-content:center;padding:0}
.wb-thdot i{display:block;border-radius:50%;background:#222}
.wb-thdot:hover{background:var(--wb-hover)}
.wb-thdot.on{border-color:var(--accent)}
.wb-cols{display:grid;grid-template-columns:repeat(4,44px);gap:6px;justify-content:space-between}
.wb-col{width:44px;height:44px;border:1px solid rgba(0,0,0,.08);border-radius:3px;padding:0}
.wb-col:hover{outline:2px solid #c3d3cd;outline-offset:1px}
.wb-col.on{outline:2px solid var(--accent2);outline-offset:1px}
.wb-pop-item{display:flex;align-items:center;gap:10px;width:100%;border:none;border-bottom:1px solid #e3ebe8;background:none;padding:9px 14px;font-size:14px;text-align:left}
.wb-pop-item:last-child{border-bottom:none}
.wb-pop-item:hover:not(:disabled){background:#f2f6f5}
.wb-pop-item:disabled{opacity:.4}
.wb-pop-item span{text-decoration:underline;text-decoration-color:#b8b1a3;text-underline-offset:3px}
.wb-hidden{position:absolute;width:0;height:0;opacity:0;pointer-events:none;border:0;padding:0}

/* the board surface */
.wb-view{position:absolute;inset:0;overflow:hidden;touch-action:none;background:#fff;user-select:none;-webkit-user-select:none;cursor:crosshair}
.wb-view[data-tool=select]{cursor:default}
.wb-view[data-tool=hand]{cursor:grab}
.wb-view[data-tool=eraser]{cursor:cell}
.wb-view[data-tool=text]{cursor:text}
.wb-view[data-tool=eyedrop]{cursor:copy}
.wb-world{position:absolute;left:0;top:0;transform-origin:0 0;pointer-events:none}
.wb-layer{position:absolute;left:0;top:0;width:0;height:0}
.wb-svg{position:absolute;left:0;top:0;overflow:visible}
.wb-hl{mix-blend-mode:multiply}
.wb-text{position:absolute;white-space:pre;line-height:1.25;font-family:var(--sans)}
.wb-math{position:absolute;white-space:nowrap;line-height:1.3}
.wb-math.raw{font-family:ui-monospace,Consolas,monospace;font-size:.8em;background:#f3f3f3;padding:2px 5px;border-radius:4px}
/* sticky notes: square paper, a faint adhesive band at the top, and a lifted
   bottom edge whose shadow curls out under the right-hand corner */
.wb-sticky{position:absolute;border-radius:0 0 2px 2px;padding:14px 14px 12px;
  background-image:linear-gradient(to bottom,rgba(60,45,0,.065) 0,rgba(60,45,0,.05) 17%,rgba(60,45,0,0) 27%),linear-gradient(160deg,rgba(255,255,255,0) 70%,rgba(0,0,0,.05));
  box-shadow:0 1px 1px rgba(0,0,0,.12),0 0 0 .5px rgba(0,0,0,.05)}
.wb-sticky::after{content:"";position:absolute;z-index:-1;right:8px;bottom:14px;width:55%;height:20px;
  box-shadow:0 15px 10px rgba(40,32,20,.36);transform:rotate(3deg)}
.wb-sticky::before{content:"";position:absolute;z-index:-1;left:8px;bottom:14px;width:40%;height:20px;
  box-shadow:0 12px 10px rgba(40,32,20,.14);transform:rotate(-1.5deg)}
.wb-sticky-txt{white-space:pre-wrap;word-break:break-word;font-size:17px;line-height:1.3;color:#2b2618;height:100%;overflow:hidden}
.wb-img{position:absolute;display:block;user-select:none;-webkit-user-drag:none}
.wb-editor{position:absolute;pointer-events:auto;margin:0;max-width:none;min-width:0;border:2px dashed var(--accent);border-radius:4px;background:rgba(255,255,255,.9);outline:none;resize:none;overflow:hidden;font-family:var(--sans)}
.wb-text-ed{min-height:0;line-height:1.25;padding:0 2px;white-space:pre}
.wb-sticky-ed{resize:both;min-width:40px;min-height:40px;padding:12px 12px 10px;font-size:17px;line-height:1.3;color:#2b2618;border-radius:0;background-image:linear-gradient(to bottom,rgba(60,45,0,.065) 0,rgba(60,45,0,.05) 17%,rgba(60,45,0,0) 27%);box-shadow:0 6px 14px rgba(40,32,20,.22)}
.wb-selbox{position:absolute;border:1.5px dashed var(--accent);border-radius:4px;pointer-events:none}
.wb-seldel{position:absolute;top:-14px;right:-14px;width:28px;height:28px;border-radius:50%;border:none;background:var(--red);color:#fff;font-size:13px;pointer-events:auto;box-shadow:var(--shadow)}
.wb-handle{position:absolute;right:-8px;bottom:-8px;width:16px;height:16px;border-radius:4px;background:var(--accent);border:2px solid #fff;pointer-events:auto;cursor:nwse-resize;touch-action:none}
.wb-hovertag{position:absolute;pointer-events:none;background:var(--ink);color:#fff;font-size:12px;padding:2px 8px;border-radius:6px;white-space:nowrap}

/* maths dialog */
.wb-mathdlg{max-width:620px}
.wb-mathsrc{font-family:ui-monospace,Consolas,monospace;font-size:15px;min-height:70px}
.wb-palette{display:flex;flex-wrap:wrap;gap:4px;margin-top:8px;max-height:150px;overflow-y:auto}
.wb-palbtn{min-width:38px;height:34px;border:1px solid var(--line);border-radius:7px;background:#fff;font-size:15px;padding:0 6px}
.wb-palbtn:hover{background:var(--accent-soft);border-color:var(--accent)}
.wb-mathprev{min-height:56px;border:1px solid var(--line);border-radius:8px;padding:12px;font-size:24px;overflow-x:auto;background:#fff}
.wb-mathprev.raw{font-size:14px;color:var(--muted)}

@media(max-width:700px){
  .wb-head{padding:4px 6px 0;gap:2px}
  .wb-back span,.wb-title,.wb-presence{display:none}
  .wb-tab{padding:6px 9px 9px}
  .wb-ribbon{margin:0 6px 6px;min-height:56px}
  .wb-main{position:relative}
  .wb-pages{position:absolute;z-index:6;top:0;bottom:6px;left:0;box-shadow:0 8px 28px rgba(30,25,18,.25)}
  .wb-stage{margin:0 6px 6px}
}


/* ================= exercise book =================
   The site is a green school exercise book. Squared paper (24px squares, the
   body line height), a red margin rule, the menu written in the margin, and
   content written on the lines. Colour jobs: green = done / where you are /
   main action; red = needs attention; the pink margin rule is the paper. */
:root{
  --paper:#fbfcfb; --grid:#e6edeb; --rule:#e0837a; --sq:24px;
  --card:#fff; --ink:#1c2a2f; --muted:#56646a; --line:#d5dfdc;
  --accent:#2f5d50; --accent-soft:#e3eeea; --accent2:#b3261e;
  --red:#b3261e; --red-soft:#fbe9e7; --amber:#8a5a00; --amber-soft:#fbf0d9;
  --green:#2f5d50; --green-soft:#e3eeea; --radius:4px; --shadow:none;
}
body{background-color:var(--paper);background-image:linear-gradient(var(--grid) 1px,transparent 1px),linear-gradient(90deg,var(--grid) 1px,transparent 1px);background-size:var(--sq) var(--sq);font-size:16px;line-height:var(--sq);color:var(--ink)}
:focus-visible{outline:2px solid var(--accent);outline-offset:2px}
::selection{background:var(--accent-soft)}

/* menu written in the margin */
.sidenav{background:transparent;border-right:2px solid var(--rule);padding:12px 12px}
.sn-head{padding:0 6px 24px;min-height:var(--sq)}
.sn-head .brand{color:var(--accent);font-weight:800;font-size:18px;letter-spacing:-.01em}
.sn-group{margin-bottom:24px}
.sn-gtitle{color:var(--muted);font-weight:600;font-size:13px;line-height:var(--sq);padding:0 10px}
.sn-list{gap:0}
.sn-item{min-height:40px;margin:4px 0;padding:8px 10px;line-height:var(--sq);color:var(--ink)}
.sn-item:hover{background:rgba(47,93,80,.07)}
.sn-item.active{background:rgba(47,93,80,.11);box-shadow:none;color:var(--accent);font-weight:650}
.sn-item.active .sn-ico{color:var(--accent)}
.sn-foot{border-top:1px solid var(--line)}
.sn-mobilebar{background:rgba(251,252,251,.97);border-bottom:2px solid var(--rule)}
.sn-mobilebar .brand{color:var(--accent)}

/* page written on the lines */
.shell-nav~.wrap{padding:var(--sq) 48px 96px 48px}
h1{font-size:30px;line-height:48px;margin:0 0 var(--sq);font-weight:750;letter-spacing:-.015em}
h1 .ruled{background:linear-gradient(var(--accent),var(--accent)) left calc(100% - 6px)/100% 2px no-repeat;padding-bottom:6px}
.btn{border-radius:var(--radius);min-height:40px;line-height:var(--sq)}
.btn.secondary{background:#fff;border:1px solid var(--line);color:var(--ink)}
.btn.secondary:hover{border-color:var(--accent);filter:none}

/* tracker */
.tracker{max-width:816px}
.tally{margin:0 0 var(--sq)}
.tally-line{margin:0;line-height:var(--sq)}
.tally-flags{display:flex;gap:8px;flex-wrap:wrap;min-height:var(--sq)}
.tally-flags:empty{display:none}
.tally-flags .pill{line-height:20px;margin-top:2px}
.pill{border-radius:3px;font-weight:650}
.pill.red{background:var(--red-soft);color:var(--red)}
.pill.amber{background:var(--amber-soft);color:var(--amber)}
.pill.green{background:var(--green-soft);color:var(--green)}
.pill.worried{background:var(--red-soft);color:var(--red)}
.exam-format{margin:0 0 var(--sq);color:var(--muted);font-size:14px;line-height:var(--sq);max-width:68ch}
.exam-format b{color:var(--ink);font-weight:650}
.section-block{margin:0}
.section-head{display:flex;align-items:center;gap:10px;width:100%;height:48px;padding:0 4px;margin:0;border:none;border-radius:0;
  background:linear-gradient(var(--accent),var(--accent)) left bottom/100% 2px no-repeat;text-align:left;font:inherit;color:var(--ink);cursor:pointer}
.section-head:hover{background-color:rgba(47,93,80,.05)}
.section-head .sn-ico{width:18px;height:18px;color:var(--accent);transform:rotate(-90deg);transition:transform .15s ease-out}
.section-head[aria-expanded="true"] .sn-ico{transform:none}
.sec-title{font-weight:700;font-size:17px;flex:1}
.section-head .count{margin-left:auto;font-size:14px;color:var(--muted);white-space:nowrap}
.section-body{padding:0 0 var(--sq)}
.topic{display:grid;grid-template-columns:72px minmax(0,1fr) auto auto;align-items:center;column-gap:12px;min-height:48px;padding:12px 0;border:none;
  background:linear-gradient(var(--line),var(--line)) left bottom/100% 1px no-repeat;flex-wrap:nowrap}
.topic:last-child{background:none}
.topic-margin{display:flex;align-items:center;gap:8px;height:var(--sq)}
.topic .code{font-weight:750;color:var(--ink);font-size:15px}
.topic .title{line-height:var(--sq);min-width:0}
.tick{width:22px;height:22px;border-radius:3px;border:1.5px solid #8d9a96;background:#fff;padding:0;display:inline-flex;align-items:center;justify-content:center;color:#fff;cursor:pointer}
.tick .sn-ico{width:16px;height:16px;stroke-width:2.6;opacity:0}
.tick.on{background:var(--green);border-color:var(--green)}.tick.on .sn-ico{opacity:1}
.tickmark{width:22px;height:22px;display:inline-flex;align-items:center;justify-content:center;color:var(--green)}
.tickmark .sn-ico{width:22px;height:22px;stroke-width:2.8}
.topic-actions{display:flex;align-items:center;gap:12px}
.rag{display:inline-flex;border:1px solid var(--line);border-radius:4px;overflow:hidden;background:#fff}
.rag-opt{border:none;background:none;font:inherit;font-size:13px;font-weight:600;color:var(--muted);height:30px;padding:0 10px;cursor:pointer}
.rag-opt+.rag-opt{border-left:1px solid var(--line)}
.rag-opt:hover:not(:disabled){background:#f2f5f4;color:var(--ink)}
.rag-opt.on.red{background:var(--red);color:#fff}
.rag-opt.on.amber{background:#e0a21a;color:#2b1d00}
.rag-opt.on.green{background:var(--green);color:#fff}
.rag-opt:disabled{cursor:default}
.rag-opt:disabled:not(.on){color:#a7b1ae}
.worry{display:inline-flex;align-items:center;gap:5px;border:none;background:none;font:inherit;font-size:13px;font-weight:600;color:var(--muted);height:30px;padding:0 6px;border-radius:4px;cursor:pointer}
.worry .sn-ico{width:16px;height:16px}
.worry:hover{color:var(--ink);background:#f2f5f4}
.worry.on{color:var(--red);background:var(--red-soft)}
.worry.on .sn-ico{fill:var(--red)}
.notes-btn{display:inline-flex;align-items:center;gap:2px;border:none;background:none;font:inherit;font-size:13px;font-weight:600;color:var(--accent);height:30px;padding:0 4px;cursor:pointer}
.notes-btn .sn-ico{width:16px;height:16px;transition:transform .15s ease-out}
.notes-btn[aria-expanded="true"] .sn-ico{transform:rotate(180deg)}
.topic .expander{grid-column:2/-1;background:#fff;border:1px solid var(--line);border-radius:4px;margin-top:12px}
.topic.flash{animation:topicflash 1.6s ease-out}

@media(max-width:759px){
  body{background-image:none}
  .sidenav{background-color:var(--paper);box-shadow:none}
  .shell-nav.open .sidenav{box-shadow:0 8px 28px rgba(30,25,18,.25)}
  .shell-nav~.wrap{padding:76px 16px 64px}
  h1{font-size:24px;line-height:36px}
  .topic{grid-template-columns:52px minmax(0,1fr) auto;column-gap:8px;row-gap:8px;padding:12px 0}
  .topic-margin{align-self:start}
  .topic-actions{grid-column:2/-1;grid-row:2;gap:8px;flex-wrap:wrap}
  .rag-opt{height:44px;padding:0 12px;font-size:14px}
  .worry,.notes-btn{height:44px;font-size:14px}
  .notes-btn{grid-column:3;grid-row:1;align-self:start;margin-top:-10px}
  .tick{width:26px;height:26px}
  .section-head{height:52px}
}
@media(prefers-reduced-motion:reduce){*{transition-duration:.01ms!important;animation-duration:.01ms!important}}


/* ---- exercise book: shared components ----
   One corner radius (4px). Sections are ruled, not boxed. A white paper slip
   only where something is a separate, tappable thing. Green = done / current /
   main action; red = needs attention; amber = in between. */
h2{font-size:22px;line-height:36px;font-weight:700;margin:0 0 12px}
h3{font-size:18px;line-height:var(--sq);font-weight:700;margin:0 0 8px}
p{margin:0 0 12px}
.subtle{color:var(--muted);font-size:14px}
.tiny{color:var(--muted);font-size:13px}
a{color:var(--accent);text-underline-offset:3px}
hr{border-top:1px solid var(--line);margin:var(--sq) 0}
label{font-size:13px;font-weight:600;color:var(--muted);margin:12px 0 4px}
input,select,textarea{border:1px solid var(--line);border-radius:var(--radius);background:#fff;padding:8px 10px;min-height:40px;line-height:22px}
textarea{min-height:72px}
input:focus,select:focus,textarea:focus{outline:2px solid var(--accent-soft);border-color:var(--accent)}
input[type=checkbox]{min-height:0;accent-color:var(--accent)}

/* sections written on the page */
.card{background:none;border:none;border-top:1px solid var(--line);border-radius:0;box-shadow:none;padding:var(--sq) 0;margin:0}
.wrap>h1+.card,.wrap>.rowline+.card,.wrap>.tabs+div>.card:first-child{border-top:none;padding-top:0}
.card h3 .sub{font-family:var(--sans);font-weight:500;color:var(--muted);font-size:14px;margin-left:6px}
.card.note{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:12px 16px;margin-top:var(--sq)}
.grid{gap:0 32px}
/* a slip of paper: a separate thing you can open */
.card.clickable{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:16px;margin-bottom:16px;transition:border-color .15s ease-out}
.card.clickable:hover{border-color:var(--accent)}
.grid.two>.card.clickable{margin-bottom:16px}
.roster-card h3{margin-bottom:4px}
.attn{color:var(--red);font-weight:650;font-size:14px}

/* buttons: one shape; primary is green ink, secondary is paper */
.btn{display:inline-flex;align-items:center;justify-content:center;gap:6px;border-radius:var(--radius);padding:8px 16px;font-weight:650;font-size:15px}
.btn .sn-ico{width:16px;height:16px}
.btn.small{min-height:32px;padding:4px 12px;font-size:14px}
.btn.secondary,.btn.ghost{background:#fff;border:1px solid var(--line);color:var(--ink)}
.btn.secondary:hover,.btn.ghost:hover{border-color:var(--accent);filter:none}
.btn.danger{background:var(--red)}
.btnrow{gap:8px;margin-top:12px}

/* small labels */
.pill{display:inline-flex;align-items:center;gap:4px;border-radius:3px;padding:2px 8px;font-size:12.5px;line-height:18px}
.pill .sn-ico{width:13px;height:13px}
.pill.grey{background:#eef3f1;color:var(--muted)}
.pill.blue{background:#e6eef6;color:#1f4f7a}
.chip{background:#fff;border:1px solid var(--line);border-radius:3px;padding:1px 8px;font-size:13px;color:var(--ink)}
.badge{background:var(--red);border-radius:9px;font-size:11px;line-height:16px;padding:0 5px}
.empty{color:var(--muted);text-align:left;font-style:normal;padding:12px 0}

/* tabs: a ruled line with the current tab underlined in green */
.tabs{gap:4px;border-bottom:1px solid var(--line);margin-bottom:var(--sq)}
.tab{border:none!important;background:none!important;border-radius:0;padding:12px 12px;color:var(--muted);font-weight:600;margin-bottom:-1px}
.tab:hover{color:var(--ink)}
.tab.active{color:var(--ink);box-shadow:inset 0 -2px 0 var(--accent)}

/* lessons: date first, no coloured side stripe */
.lesson{border-left:none;padding:12px 0;margin:0;border-top:1px solid var(--line)}
.lesson:first-child{border-top:none}
.lesson.past .when{color:var(--muted)}
.lesson .when{font-family:var(--sans);font-weight:700}
.hw{padding:6px 0}
.dayrow{border-bottom:1px solid var(--line);padding:12px 0}

/* calendar: months are ruled boxes like a planner page */
.calmonth{background:#fff;border:1px solid var(--line);border-radius:var(--radius);padding:12px}
.calmonth.now{border-color:var(--accent);box-shadow:inset 0 0 0 1px var(--accent)}
.calmname{font-family:var(--sans);color:var(--ink)}
.calday{border-radius:3px}
.calday:hover{background:#eef3f1;border-color:var(--line)}
.calday.has{background:var(--accent-soft)}
.calday.busy,.calkey i.k-busy{background:#bfd6cd}
.calday.packed{background:var(--accent)}
.calflag{color:var(--red)}.calflag .sn-ico{width:9px;height:9px;fill:currentColor}
.calbar .yr{font-family:var(--sans)}
.calkey .sn-ico{width:13px;height:13px;vertical-align:-2px;color:var(--red)}

/* review queue: separate items to act on, as paper slips */
.queue-item{background:#fff;border:1px solid var(--line);border-left:1px solid var(--line);border-radius:var(--radius);padding:16px;margin-bottom:12px}
.answerbox,.expander{background:#f5f8f7;border-radius:var(--radius)}

/* paper sitting */
.partrow{border-radius:var(--radius);border-color:var(--line);padding:12px 14px}
.partrow .plabel{font-family:var(--sans)}
.partrow.correct{border-color:#8fb8a6;background:var(--green-soft)}
.partrow.incorrect{border-color:#e2a7a1;background:var(--red-soft)}
.partrow.pending{border-color:#e6c77d;background:var(--amber-soft)}
.timerbox{border-radius:var(--radius);background:var(--ink)}
.scoreband{background:var(--accent-soft);border:none;border-radius:var(--radius)}
.pdfframe{border-radius:var(--radius);border-color:var(--line)}
.qblock{border-radius:var(--radius);border-color:var(--line)}

/* dialogs and messages */
.modal{border-radius:var(--radius);box-shadow:0 18px 50px rgba(20,35,30,.28);padding:24px}
.modal-back{background:rgba(20,32,28,.5)}
.toast{border-radius:var(--radius);background:var(--ink)}
.toast.warn{background:#7a4e00}
.commentrow{border-bottom:1px solid var(--line)}
.commentrow .who.tutor{color:var(--accent)}
.commentrow .who.student{color:#1f4f7a}

/* sign-in: a sheet of the book's paper */
.auth{border:1px solid var(--line);border-radius:var(--radius);box-shadow:0 1px 2px rgba(20,35,30,.06);padding:32px}
.auth .brand{font-family:var(--sans);color:var(--accent);font-weight:800;font-size:24px;line-height:36px;margin-bottom:var(--sq)}
.auth label{margin-top:0}

/* student home */
.subject-list{margin-bottom:var(--sq)}
.subject-row{display:flex;align-items:center;gap:16px;flex-wrap:wrap;padding:var(--sq) 0;border-top:1px solid var(--line)}
.subject-row:first-child{border-top:none;padding-top:0}
.subject-main{flex:1;min-width:220px}
.subject-main p{margin:0}
.subject-row .btnrow{margin-top:0}
.home-pair{border-top:2px solid var(--accent);padding-top:var(--sq)}
.home-pair>.card{border-top:none;padding-top:0}

/* old top bar (onboarding page only) */
.topbar{background:rgba(251,252,251,.96);border-bottom:2px solid var(--rule)}

@media(max-width:759px){
  .grid.two{grid-template-columns:1fr}
  .home-pair>.card+.card{border-top:1px solid var(--line);padding-top:var(--sq)}
  .btn{min-height:44px}
  .tab{padding:12px 10px}
}

.ruled-section{font-size:18px;line-height:var(--sq);margin:var(--sq) 0 12px;padding-bottom:8px;background:linear-gradient(var(--accent),var(--accent)) left bottom/100% 2px no-repeat}
h1+.ruled-section{margin-top:0}
@media(max-width:759px){.queue-item .rowline>input{flex-basis:100%!important}}
h1 .sub{font-family:var(--sans);font-weight:500;color:var(--muted);font-size:18px}


/* ---- the side menu, in pen ink ----
   Labels in the site font (Inter) in blue-black biro ink; the current page is
   in green pen with a hand-drawn underline. Rows are compact so the whole
   menu fits without scrolling, and every hover highlight has clear space
   around it (nothing touches, including the hide button). */
:root{--pen:var(--sans);--biro:#1f3a7a}
.sidenav{padding:14px 12px 12px;overflow-y:auto}
.sn-head{min-height:36px;padding:0 0 14px 8px;gap:8px}
.sn-head .brand{font-family:var(--pen);font-weight:800;font-size:18px;line-height:28px;color:var(--accent);letter-spacing:-.01em}
.sn-collapse{flex:none;width:32px;height:32px;padding:0;align-items:center;justify-content:center;border-radius:6px;margin-left:auto}
.sn-collapse:hover{background:rgba(31,58,122,.08);color:var(--biro)}
.sn-group{margin-bottom:12px}
.sn-gtitle{font-family:var(--pen);font-weight:600;font-size:13px;line-height:20px;color:#6a7591;padding:0 8px 2px}
.sn-list{gap:4px}
.sn-item{min-height:32px;margin:0;padding:4px 8px;gap:10px;line-height:22px;border-radius:5px 7px 6px 4px;
  font-family:var(--pen);font-size:15px;color:var(--biro)}
.sn-item .sn-ico{width:18px;height:18px;stroke-width:1.7;color:var(--biro)}
.sn-item:hover{background:rgba(31,58,122,.07)}
.sn-item.active{background:rgba(47,93,80,.1);color:var(--accent);font-weight:650}
.sn-item.active .sn-ico{color:var(--accent);stroke-width:2}
.sn-item.active:hover{background:rgba(47,93,80,.14)}
.sn-badge{font-family:var(--sans);font-weight:700}
.sn-tools{padding:4px 8px 8px}
.sn-link{font-family:var(--pen);font-size:13px;color:#6a7591;text-decoration-color:rgba(31,58,122,.3)}
.sn-link:hover{color:var(--biro)}
.sn-foot{padding-top:8px;gap:4px}
/* collapsed: a narrow margin of icons, same spacing rules. Laptop widths
   only: on a phone the menu is a full drawer whatever the collapse setting. */
@media(min-width:760px){
  .nav-collapsed .sidenav{padding:14px 12px 12px}
  .nav-collapsed .sn-head{padding:0 0 12px;align-items:center}
  .nav-collapsed .sn-collapse{margin:0}
  .nav-collapsed .sn-group{padding-top:8px;margin-bottom:8px}
  .nav-collapsed .sn-item{width:40px;min-height:36px;padding:0;justify-content:center;margin:0 auto}
}
/* short screens: tighten further rather than scroll */
@media(max-height:640px) and (min-width:760px){
  .sn-head{padding-bottom:8px}
  .sn-group{margin-bottom:6px}
  .sn-list{gap:2px}
  .sn-item{min-height:28px;padding:3px 8px;font-size:15px}
  .sn-gtitle{line-height:18px}
}
@media(max-width:759px){
  .sn-item{min-height:44px;font-size:16px}
}

/* phone drawer on short screens (landscape phones, small windows): tighten
   rather than scroll, keeping taps at 36px or more */
@media(max-width:759px) and (max-height:720px){
  .sidenav{padding-top:10px;padding-bottom:8px}
  .sn-head{padding-bottom:6px;min-height:32px}
  .sn-group{margin-bottom:6px}
  .sn-list{gap:2px}
  .sn-item{min-height:36px;padding:2px 8px}
  .sn-tools{padding:2px 8px 4px}
  .sn-foot{padding-top:4px}
}
@media(max-width:759px) and (max-height:600px){
  .sn-item{min-height:32px}
  .sn-gtitle{line-height:18px}
}
/* very short wide screens (a phone turned sideways): drop the group labels,
   the groups stay separated by space */
@media(min-width:760px) and (max-height:480px){
  .sidenav{padding-top:8px;padding-bottom:6px}
  .sn-head{padding-bottom:4px;min-height:28px}
  .sn-gtitle{display:none}
  .sn-group{margin-bottom:8px}
  .sn-list{gap:2px}
  .sn-item{min-height:26px;padding:1px 8px}
  .sn-tools{padding:0 8px 2px}
  .sn-foot{padding-top:2px}
}

/* whiteboard on a phone held upright: the toolbars and page list at half
   size (what Safari's 50% page zoom gave), so the board gets the room.
   The board itself starts at 50% zoom (see initialView). */
@media(max-width:600px) and (orientation:portrait) and (pointer:coarse){
  .wb-head,.wb-ribbon,.wb-pages,.wb-float{zoom:.5}
  .wb-ribbon{margin:0 6px 4px}
  .wb-stage{margin:0 4px 4px}
  /* no sideways scrolling: tools that don't fit wrap onto a second row */
  .wb-ribbon,.wb-float{flex-wrap:wrap;overflow-x:hidden;row-gap:4px;max-width:none}
  .wb-ribbon .wb-pane{flex:1 1 100%;min-width:0;flex-wrap:wrap;row-gap:4px}
  .wb-ribbon .wb-ctx{flex-wrap:wrap;margin-left:0;padding-left:0;border-left:none}
  .wb-float{width:calc(200% - 16px)}
}
/* phone turned sideways: the toolbar is shrunk just enough to fit the width
   on one row (--wb-rz is worked out from the screen width in app.js), so the
   board keeps its height; anything extra, like the "Selected" group, wraps */
@media(orientation:landscape) and (pointer:coarse) and (max-height:500px){
  .wb-head,.wb-ribbon,.wb-float{zoom:var(--wb-rz,1)}
  .wb-ribbon,.wb-float{flex-wrap:wrap;overflow-x:hidden}
  .wb-ribbon{margin-bottom:4px}
}
.wb-view{-webkit-touch-callout:none}

/* stylus configuration */
.wb-stylus{width:320px!important}
.wb-stylus-list{display:flex;flex-direction:column;gap:6px;margin-top:8px}
.wb-stylus-row{display:flex;flex-direction:column;gap:4px;padding:8px;margin:0 -8px;border-radius:6px;transition:background-color .12s ease-out,box-shadow .12s ease-out}
.wb-stylus-row.hit{background:var(--accent-soft);box-shadow:inset 0 0 0 2px var(--accent)}
.wb-stylus-lbl{font-size:13.5px;font-weight:650;margin:0}
.wb-stylus-ctl{display:flex;gap:6px;align-items:center}
.wb-stylus-sel{flex:1;min-height:36px;padding:6px 8px;font-size:14px}
.wb-stylus-del{border:none;background:none;border-radius:5px;width:32px;height:32px;display:flex;align-items:center;justify-content:center;color:var(--muted);flex:none}
.wb-stylus-del:hover{background:var(--red-soft);color:var(--red)}
.wb-stylus-del .wb-ico{width:16px;height:16px}
.wb-stylus-add{display:flex;align-items:center;gap:6px;border:1px dashed var(--line);background:none;border-radius:6px;padding:8px 10px;font-size:14px;font-weight:600;color:var(--accent);text-align:left}
.wb-stylus-add:hover{border-color:var(--accent);background:var(--accent-soft)}
.wb-stylus-add .wb-ico{width:16px;height:16px}
.wb-stylus-row.adding{background:var(--amber-soft)}
.wb-stylus-wait{font-size:13px;color:var(--ink);display:flex;gap:8px;align-items:center;flex-wrap:wrap}
.wb-stylus-link{border:none;background:none;color:var(--accent);font-weight:600;text-decoration:underline;padding:0;font-size:13px}
.wb-stylus-status{margin-top:10px}
.wb-stylus-status.hit{background:var(--accent-soft)}

/* notes: recording which part of the screen a note is about */
.rec-banner{position:fixed;left:50%;transform:translateX(-50%);bottom:calc(16px + env(safe-area-inset-bottom,0px));z-index:120;display:flex;align-items:center;gap:10px;
  background:#fff;border:1px solid var(--line);border-left:1px solid var(--line);border-radius:var(--radius);padding:8px 10px 8px 12px;box-shadow:0 8px 24px rgba(20,35,30,.18);font-size:14px;max-width:calc(100% - 24px)}
.rec-dot{width:10px;height:10px;border-radius:50%;background:var(--red);flex:none;animation:recpulse 1.4s ease-in-out infinite}
@keyframes recpulse{50%{opacity:.35}}
.rec-outline{position:fixed;z-index:119;pointer-events:none;border:2px solid var(--red);border-radius:4px;background:rgba(179,38,30,.06);display:none}
@media(prefers-reduced-motion:reduce){.rec-dot{animation:none}}
.rec-banner.confirm{flex-direction:column;align-items:stretch;gap:8px;width:min(560px,calc(100% - 24px))}
.rec-picked{font-size:14px;line-height:20px}
.rec-actions{display:flex;gap:8px;flex-wrap:wrap}
/* notes: picked part and screenshot under the "Which screen" box */
.note-pick{margin-top:8px}
.note-extras:empty{display:none}
.note-extras{display:flex;flex-direction:column;gap:8px;margin-top:8px}
.note-part{display:flex;align-items:flex-start;gap:10px;font-size:14px;line-height:20px;padding:8px 10px;border:1px solid var(--line);border-radius:var(--radius);background:var(--card,#fff)}
.note-shot{display:block;max-width:min(320px,100%);height:auto;border:1px solid var(--line);border-radius:var(--radius)}
.note-part .note-shot{flex:1 1 auto}
.note-shot-row{margin-top:6px}
.note-shot-row .btnrow{margin-top:6px}
.rec-shot{display:block;max-width:100%;max-height:40vh;object-fit:contain;border:1px solid var(--line);border-radius:var(--radius)}
/* side menu: Students drop-down (arrow opens a list of students under it) */
.sn-chev{display:flex;align-items:center;justify-content:center;width:26px;height:26px;margin:-2px -4px -2px auto;border-radius:4px;color:var(--muted);flex:none}
.sn-badge + .sn-chev{margin-left:0}
.sn-chev .sn-ico{width:16px;height:16px;transition:transform .15s}
.sn-chev:hover{background:rgba(31,58,122,.12);color:var(--biro)}
.sn-chev:focus-visible{outline:2px solid var(--accent);outline-offset:1px}
.sub-open .sn-chev .sn-ico{transform:rotate(180deg)}
.sn-sub{display:flex;flex-direction:column;gap:1px;margin:0 0 4px 30px;padding-left:8px;border-left:1px solid var(--line);max-height:calc(var(--sq) * 7);overflow-y:auto}
.sn-subitem{display:block;width:100%;border:none;background:none;text-align:left;font:inherit;font-size:14px;line-height:22px;padding:2px 8px;border-radius:4px;color:var(--ink);white-space:nowrap;overflow:hidden;text-overflow:ellipsis;cursor:pointer}
.sn-subitem:hover{background:rgba(31,58,122,.07)}
.sn-subitem.active{color:var(--accent);font-weight:650;background:rgba(47,93,80,.1)}
.sn-sub-note{font-size:13px;line-height:22px;padding:2px 8px;color:var(--muted)}
.editing .sn-chev,.editing .sn-sub{display:none}
@media(prefers-reduced-motion:reduce){.sn-chev .sn-ico{transition:none}}
@media(min-width:760px){.nav-collapsed .sn-chev,.nav-collapsed .sn-sub{display:none}}
@media(max-width:759px){.sn-chev{width:36px;height:36px}.sn-subitem{font-size:15px;line-height:24px;padding:6px 8px}}
/* dividers between sections: darker than the squared paper so they read as
   rules, with one square of space above and below each */
:root{--divider:#9fafaa}
.card{border-top-color:var(--divider);margin:var(--sq) 0 0;padding:var(--sq) 0 0}
.card>:first-child{margin-top:0}
.card>:last-child{margin-bottom:0}
.wrap>h1+.card,.wrap>.rowline+.card,.wrap>.tabs+div>.card:first-child{margin-top:0}
hr{border-top-color:var(--divider);margin:var(--sq) 0}
.note-row{padding:12px 0;border-bottom:1px solid var(--divider);align-items:flex-start}
.note-row:last-child{border-bottom:none;padding-bottom:0}
.list-row{padding:5px 0;border-bottom:1px solid var(--divider)}
.sn-foot{border-top-color:var(--divider)}
/* toasts fade out rather than vanish */
.toast{transition:opacity .4s ease-out,transform .4s ease-out}
.toast.out{opacity:0;transform:translateY(-6px)}
@media(prefers-reduced-motion:reduce){.toast{transition:opacity .4s}.toast.out{transform:none}}
/* recording bar: keyboard wording on laptops, a Screenshot button on touch screens */
.rec-touch,.rec-shoot{display:none}
@media(hover:none) and (pointer:coarse){
  .rec-keys{display:none}
  .rec-touch{display:inline}
  .rec-shoot{display:inline-flex}
  .rec-banner:not(.confirm){width:calc(100% - 24px);flex-wrap:wrap}
  .rec-banner:not(.confirm)>span:nth-child(2){flex:1 1 calc(100% - 30px)}
  .rec-banner:not(.confirm) .rec-shoot{margin-left:20px}
}
/* recording on a touch screen: the ring that fills while a finger is held */
.rec-hold{position:fixed;width:72px;height:72px;margin:-36px 0 0 -36px;pointer-events:none;z-index:121}
.rec-hold svg{width:100%;height:100%;transform:rotate(-90deg)}
.rec-hold circle{fill:none;stroke-width:5}
.rec-hold-bg{stroke:rgba(179,38,30,.2)}
.rec-hold-fill{stroke:var(--red);stroke-linecap:round;stroke-dasharray:163.4;stroke-dashoffset:163.4;animation:rechold var(--hold,1.5s) linear forwards}
.rec-hold{transition:opacity .25s ease-out}
.rec-hold.out{opacity:0}
@keyframes rechold{to{stroke-dashoffset:0}}
@media(hover:none) and (pointer:coarse){
  .rec-on body{-webkit-user-select:none;user-select:none;-webkit-touch-callout:none}
  .rec-on input,.rec-on textarea,.rec-on [contenteditable]{-webkit-user-select:text;user-select:text}
}
.rec-hint{font-size:13px;line-height:18px;color:var(--muted)}
.rec-banner.confirm .rec-touch{display:none}
@media(hover:none) and (pointer:coarse){.rec-banner.confirm .rec-touch{display:inline}}
/* whiteboard font size box: the exercise-book 40px input height made it
   overflow its 30px frame, leaving the number at the top; fit it and centre */
.wb-fontinp{min-height:0;height:100%;line-height:normal;padding:0 4px;text-align:center}
/* ---- calls: Call button, incoming-call banner and the call panel ---- */
.call-start{display:inline-flex;align-items:center;gap:6px}
.call-start .sn-ico{width:17px;height:17px}
.wb-head .call-start{margin-left:10px;min-height:32px}
.call-ring{position:fixed;top:14px;left:50%;transform:translateX(-50%);z-index:130;display:flex;align-items:center;gap:12px;
  width:min(440px,calc(100% - 24px));background:#fff;border:1px solid var(--line);border-radius:var(--radius);box-shadow:0 10px 30px rgba(0,0,0,.18);padding:12px 14px}
.call-ring b{font-size:16px}
.call-ring-dot{width:12px;height:12px;border-radius:50%;background:var(--accent);flex:none;animation:recpulse 1.2s ease-in-out infinite}
.call-answer{display:inline-flex;align-items:center;gap:6px}
.call-answer .sn-ico{width:18px;height:18px}
.call-panel{position:fixed;right:16px;bottom:calc(16px + env(safe-area-inset-bottom,0px));z-index:125;width:300px;background:#fff;
  border:1px solid var(--line);border-radius:var(--radius);box-shadow:0 10px 30px rgba(0,0,0,.18);padding:10px 12px;display:flex;flex-direction:column;gap:8px}
.call-panel.has-video{width:400px}
.call-panel.big{width:min(1100px,calc(100vw - 32px))}
.call-top{display:flex;align-items:center;gap:10px}
.call-top b{font-size:15px}
.call-live-dot{width:10px;height:10px;border-radius:50%;background:#b8c2bf;flex:none}
.call-live-dot.on{background:var(--accent)}
.call-ctrls{display:flex;gap:6px;flex-wrap:wrap}
.call-btn{display:inline-flex;flex-direction:column;align-items:center;justify-content:center;gap:2px;flex:1 1 0;min-width:58px;min-height:52px;padding:6px 4px;
  border:1px solid var(--line);border-radius:var(--radius);background:#fff;color:var(--ink);font:inherit;font-size:12px;font-weight:600;line-height:14px;cursor:pointer}
.call-btn .sn-ico{width:20px;height:20px}
.call-btn:hover{border-color:var(--accent)}
.call-btn.off{background:#fbeceb;border-color:#e9b8b4;color:var(--red)}
.call-btn.on{background:rgba(47,93,80,.1);border-color:var(--accent);color:var(--accent)}
.call-btn.hang{background:var(--red);border-color:var(--red);color:#fff}
.call-btn.hang .sn-ico{transform:rotate(135deg)}
.call-btn.hang:hover{filter:brightness(1.08)}
.call-media{position:relative;background:#1c2a2f;border-radius:var(--radius);overflow:hidden;aspect-ratio:16/9}
.call-panel.big .call-media{aspect-ratio:auto;height:min(72vh,calc(100vh - 200px))}
.call-main{width:100%;height:100%;object-fit:cover;display:block}
.call-main.screen{object-fit:contain;background:#111}
.call-main.empty{display:flex;align-items:center;justify-content:center;color:#cfd8d5;font-size:13px}
.call-pip{position:absolute;right:8px;bottom:8px;width:28%;aspect-ratio:4/3;object-fit:cover;border-radius:4px;border:2px solid #fff;background:#000}
.call-self{position:absolute;left:8px;bottom:8px;width:24%;aspect-ratio:4/3;object-fit:cover;border-radius:4px;border:2px solid #fff;background:#000;transform:scaleX(-1)}
.call-size{position:absolute;top:6px;right:6px;width:32px;height:32px;display:flex;align-items:center;justify-content:center;border:none;border-radius:4px;
  background:rgba(0,0,0,.45);color:#fff;cursor:pointer}
.call-size .sn-ico{width:18px;height:18px}
.call-audio{display:none}
@media(max-width:759px){
  .call-panel,.call-panel.has-video,.call-panel.big{left:12px;right:12px;width:auto}
  .call-panel.big .call-media{height:min(60vh,calc(100vh - 220px))}
  .wb-head .call-start span{display:none}
}
@media(prefers-reduced-motion:reduce){.call-ring-dot{animation:none}}
.call-panel.big .call-self,.call-panel.big .call-pip{width:min(24%,180px)}
.call-ring{flex-wrap:wrap}
.call-ring-btns{display:flex;gap:8px;flex-wrap:wrap}
.call-answer-board{display:inline-flex;align-items:center;gap:6px}
.call-answer-board .sn-ico{width:18px;height:18px}
.call-ring{width:min(620px,calc(100% - 24px))}
@media(max-width:620px){.call-ring-btns{flex:1 1 100%}.call-ring-btns .btn{flex:1 1 auto;justify-content:center}}

/* ---- maths keys (spec: claude/platform/maths-keyboard.md) ----
   A strip of the exercise book: tab names in the margin, the red margin rule,
   keys drawn as squares on the squared paper (48px = two squares). */
math-field.mk-field{display:block;width:100%;min-height:40px;font-size:18px;padding:4px 8px;border:1px solid var(--line);border-radius:var(--radius);background:#fff;color:var(--ink);--caret-color:var(--accent);--selection-background-color:var(--accent-soft);--placeholder-color:var(--muted);--contains-highlight-background-color:transparent}
math-field.mk-field:focus-within{outline:2px solid var(--accent);outline-offset:1px}
math-field.mk-field[disabled]{background:#f5f8f7;color:var(--muted)}
math-field.mk-field::part(virtual-keyboard-toggle),math-field.mk-field::part(menu-toggle){display:none}
.mk-numwrap{min-width:0}
.mk-msg:empty{display:none}
.partline .mk-keybox{width:150px}
.partline .mk-keybox math-field.mk-field{min-height:36px;font-size:16px;padding:2px 6px}
.partline .mk{flex-basis:100%}
.mk{display:grid;grid-template-columns:auto 1fr;margin-top:8px;background-color:var(--paper);background-image:linear-gradient(var(--grid) 1px,transparent 1px),linear-gradient(90deg,var(--grid) 1px,transparent 1px);background-size:var(--sq) var(--sq);border-top:1px solid var(--divider);border-bottom:1px solid var(--divider)}
.mk-tabs{display:flex;flex-direction:column;padding:6px 8px 6px 4px;border-right:2px solid var(--rule);min-width:92px}
.mk-tab{all:unset;-webkit-tap-highlight-color:transparent;cursor:pointer;font:500 14px/24px var(--sans);color:var(--biro);padding:0 8px;border-radius:var(--radius);white-space:nowrap}
.mk-tab:hover{background:rgba(31,58,122,.07)}
.mk-tab:focus-visible{outline:2px solid var(--accent)}
.mk-tab[aria-selected=true]{color:var(--accent);font-weight:650;background:rgba(47,93,80,.11)}
.mk-body{padding:12px 12px 12px 24px;display:flex;flex-direction:column;gap:12px;min-width:0}
.mk-keys{display:flex;flex-wrap:wrap;padding:1px 0 0 1px;max-width:331px}
.mk-key{all:unset;-webkit-tap-highlight-color:transparent;box-sizing:border-box;flex:0 0 48px;height:48px;margin:-1px 0 0 -1px;display:flex;align-items:center;justify-content:center;cursor:pointer;color:var(--biro);border:1px solid #b9c8c3;background:rgba(255,255,255,.6);font:500 17px var(--sans);overflow:hidden}
.mk-key .katex{font-size:1.15em;color:var(--biro)}
.mk-key .katex-display{margin:0}
.mk-key.wide{flex-basis:95px}
.mk-key.wide3{flex-basis:142px}
.mk-key:hover{background:var(--accent-soft)}
.mk-key:active{background:#d3e5de}
.mk-key:focus-visible{outline:2px solid var(--accent);outline-offset:-2px}
.mk-br{flex-basis:100%;height:0}
.mk-edit .mk-key{color:var(--muted)}
.mk-edit .mk-key .katex{color:var(--muted)}
.mk-abc{font-size:15px}
.mk-hint{font-size:13px;line-height:var(--sq);color:var(--muted)}
.mk-syms{max-width:none;margin-top:8px}
.mk-syms .mk-key{flex-basis:36px;height:36px;font-size:16px}
/* laptops: the page is already squared paper, so the strip is a plain white
   slip (like other separate things you tap) rather than squares on squares */
.mk:not(.dock){background-color:#fff;background-image:none;border:1px solid var(--line);border-radius:var(--radius)}
.mk:not(.dock) .mk-key{background:#fff}
.mk:not(.dock) .mk-tabs{padding-top:8px;padding-bottom:8px}
.mk.dock{position:fixed;left:0;right:0;bottom:0;margin:0;z-index:900}
.mk.dock .mk-tabs{min-width:0;padding-left:8px}
.mk.dock .mk-tab{font-size:13px;padding:0 6px}
.mk.dock .mk-body{padding:8px 8px 10px 10px;gap:8px}
.mk.dock .mk-keys{max-width:none}
.mk.dock .mk-keys .mk-key{flex:0 0 calc((100% - 1px) / var(--mkc) + 1px);height:44px}
.mk.dock .mk-keys .mk-key.wide{flex-basis:calc((100% - 1px) * 2 / var(--mkc) + 1px)}
.mk.dock .mk-keys .mk-key.wide3{flex-basis:calc((100% - 1px) * 3 / var(--mkc) + 1px)}
.mk.dock .mk-edit .mk-key{flex:0 0 48px}
.mk.dock .mk-edit .mk-key.wide{flex-basis:95px}
.mk.dock .mk-key .katex{font-size:.98em}
body.mk-docked{padding-bottom:var(--mk-h,240px)}
.wb-mathbox{margin:6px 0 0}
.wb-mathbox math-field.mk-field{font-size:24px;min-height:56px;padding:8px 12px}