:root{
  --bg:#FFF7EA;--ink:#1F2447;--muted:#6B6F8F;--brand:#5B4BDB;--brand-d:#4336B8;--brand-l:#EDEAFF;
  --accent:#FF8A3D;--accent-l:#FFF0E3;--good:#23B36B;--good-d:#178a50;--good-l:#E2F8EC;
  --warn:#F5A524;--warn-l:#FFF1D6;--bad:#E8505B;--bad-l:#FDE8EA;--card:#fff;--line:#DAD6F5;
  --teal:#2EC4B6;--shadow:0 5px 0 rgba(31,36,71,.07),0 14px 30px rgba(31,36,71,.08);
}
*{box-sizing:border-box}
html,body{margin:0;background:var(--bg);color:var(--ink);font-family:'Nunito',system-ui,-apple-system,'Segoe UI',Roboto,sans-serif;font-weight:700;font-size:18px;line-height:1.45;-webkit-tap-highlight-color:transparent}
body{min-height:100vh;background:
  radial-gradient(circle at 12% 8%,#ffe7c4 0,transparent 32%),
  radial-gradient(circle at 92% 12%,#e6e1ff 0,transparent 30%),var(--bg)}
h1,h2,h3{font-weight:900;line-height:1.15;margin:0 0 .4em}
h1{font-size:34px}h2{font-size:26px}h3{font-size:20px}
p{margin:.4em 0}
button{font-family:inherit}
.wrap{max-width:920px;margin:0 auto;padding:16px 16px 90px}
.muted{color:var(--muted)}
.row{display:flex;gap:12px;align-items:center;flex-wrap:wrap}
.grow{flex:1}
.center{text-align:center}
.hide{display:none!important}

/* buttons */
.btn{border:0;border-radius:18px;padding:13px 26px;font-weight:900;font-size:20px;background:var(--brand);color:#fff;box-shadow:0 5px 0 var(--brand-d);cursor:pointer;min-height:52px;transition:transform .08s,box-shadow .08s,filter .15s}
.btn:hover{filter:brightness(1.07)}
.btn:active{transform:translateY(4px);box-shadow:0 1px 0 var(--brand-d)}
.btn:focus-visible,.chip:focus-visible,.tile:focus-visible,input:focus-visible,textarea:focus-visible{outline:4px solid #ffb98a;outline-offset:2px}
.btn.good{background:var(--good);box-shadow:0 5px 0 var(--good-d)}
.btn.accent{background:var(--accent);box-shadow:0 5px 0 #d96a1f}
.btn.ghost{background:#fff;color:var(--brand);box-shadow:0 5px 0 var(--line);border:2px solid var(--line)}
.btn.sm{font-size:16px;padding:8px 16px;min-height:42px;border-radius:14px;box-shadow:0 3px 0 var(--brand-d)}
.btn.ghost.sm{box-shadow:0 3px 0 var(--line)}
.btn[disabled]{opacity:.45;cursor:not-allowed;filter:grayscale(.4);transform:none}
.iconbtn{border:2px solid var(--line);background:#fff;border-radius:14px;min-width:46px;height:46px;font-size:20px;cursor:pointer;font-weight:900;color:var(--ink)}
.chip{display:inline-flex;align-items:center;gap:6px;background:#fff;border:2px solid var(--line);border-radius:999px;padding:6px 14px;font-weight:900;font-size:16px}
.chip.star{background:var(--warn-l);border-color:#ffd88a}
.chip.fire{background:var(--accent-l);border-color:#ffc9a0}
button.chip{cursor:pointer;font-family:inherit;color:var(--ink)}
button.chip.on{background:var(--brand);color:#fff;border-color:var(--brand-d)}
button.chip[disabled]{opacity:.35;cursor:not-allowed}

/* cards */
.card{background:var(--card);border-radius:26px;box-shadow:var(--shadow);padding:22px;border:2px solid #fff}
.card.soft{background:var(--brand-l);box-shadow:none;border:2px solid var(--line)}
.grid{display:grid;gap:16px}
.grid.two{grid-template-columns:repeat(auto-fit,minmax(260px,1fr))}
.tile{display:flex;flex-direction:column;gap:8px;text-align:left;background:#fff;border:3px solid var(--line);border-radius:24px;padding:18px;cursor:pointer;box-shadow:0 5px 0 var(--line);color:var(--ink);font-family:inherit;font-size:18px;transition:transform .1s}
.tile:hover{transform:translateY(-2px);border-color:var(--brand)}
.tile .big{font-size:40px;line-height:1}
.tile.locked{opacity:.55;cursor:not-allowed}
.tile .t{font-weight:900;font-size:21px}
.tile .s{color:var(--muted);font-size:16px}
.bar{height:12px;background:#ECE9FB;border-radius:99px;overflow:hidden}
.bar>i{display:block;height:100%;background:linear-gradient(90deg,var(--brand),#8b7cff);border-radius:99px;transition:width .4s}
.bar.good>i{background:linear-gradient(90deg,var(--good),#5be39a)}
.pill{display:inline-block;border-radius:99px;padding:3px 12px;font-size:14px;font-weight:900}
.pill.ok{background:var(--good-l);color:var(--good-d)}
.pill.todo{background:var(--brand-l);color:var(--brand)}
.pill.late{background:var(--bad-l);color:var(--bad)}
.pill.warn{background:var(--warn-l);color:#9a6400}

/* top bars */
.topbar{display:flex;align-items:center;gap:12px;margin-bottom:14px;flex-wrap:wrap}
.crumbs{flex:1;min-width:140px}
.segs{display:flex;gap:6px;flex:1;min-width:160px}
.segs i{flex:1;height:12px;border-radius:99px;background:#E7E3FA;overflow:hidden;position:relative}
.segs i b{position:absolute;inset:0;width:0;background:var(--good);border-radius:99px;transition:width .4s}
.segs i.cur{outline:3px solid #cfc8ff}
.chapter{font-size:14px;color:var(--muted);font-weight:900;text-transform:uppercase;letter-spacing:.06em}

/* mascot and bubble */
.zedrow{display:flex;gap:14px;align-items:flex-start;margin-bottom:12px}
.zed{flex:0 0 auto;width:92px}
.zed svg{width:100%;height:auto;display:block}
.zed.bob svg{animation:bob .7s ease-in-out 2}
@keyframes bob{0%,100%{transform:translateY(0)}50%{transform:translateY(-8px)}}
.bubble{position:relative;background:var(--brand-l);border:2px solid var(--line);border-radius:22px;padding:14px 18px;font-size:21px;font-weight:800;flex:1;animation:pop .3s ease}
.bubble:before{content:"";position:absolute;left:-12px;top:26px;border:10px solid transparent;border-right-color:var(--line);border-left:0}
.bubble:after{content:"";position:absolute;left:-8px;top:27px;border:9px solid transparent;border-right-color:var(--brand-l);border-left:0}
@keyframes pop{from{transform:scale(.96);opacity:0}to{transform:scale(1);opacity:1}}
.goals{display:grid;gap:10px;margin-top:10px}
.goal{background:#fff;border-radius:16px;padding:10px 14px;border:2px solid var(--line);font-size:18px}

/* fractions */
.fr{display:inline-flex;flex-direction:column;align-items:center;vertical-align:middle;line-height:1.05;margin:0 .14em;font-size:.92em}
.fr i{font-style:normal;padding:0 .2em}
.fr i:first-child{border-bottom:.1em solid currentColor}
.wh{font-size:1.05em;margin-left:.1em}
b{font-weight:900}

/* number lines */
.figure{background:#fff;border:2px solid var(--line);border-radius:20px;padding:10px 6px;margin:12px 0;overflow:hidden}
svg.nl{width:100%;height:auto;display:block}
svg.nl text{font-family:'Nunito',system-ui,sans-serif;font-weight:900}
svg.nl .tk{cursor:pointer}
svg.nl .tk:hover circle{fill:#ffd9bc}
svg.nl .tk:focus-visible{outline:none}
svg.nl .tk:focus-visible circle{stroke:var(--accent);stroke-width:4}
svg.nl .newhop{animation:hopin .5s ease both}
@keyframes hopin{from{opacity:0;transform:translateY(8px)}to{opacity:1;transform:none}}

/* problem and inputs */
.prompt{font-size:22px;font-weight:800;margin-bottom:6px}
.inputs{display:flex;gap:22px;flex-wrap:wrap;margin:14px 0;align-items:flex-end}
.fld{display:flex;flex-direction:column;gap:6px}
.fld>label{font-size:15px;color:var(--muted);font-weight:900}
.fld .ctl{display:flex;align-items:center;gap:10px}
.fracin{display:inline-flex;flex-direction:column;align-items:center;gap:5px}
.fracin .vb{height:4px;width:76px;background:var(--ink);border-radius:2px}
input.num,textarea.say{font-family:inherit;font-weight:900;color:var(--ink);background:#fff;border:3px solid var(--line);border-radius:16px;text-align:center}
input.num{width:82px;font-size:28px;padding:8px}
input.num.sm{width:96px}
input.num.wide{width:210px}
.wt .step{background:#fff;border:2px solid var(--line);border-radius:16px;padding:10px 14px;margin:8px 0;font-size:21px;animation:pop .3s ease}
.wt .step b.ans{color:var(--good-d)}
.wt .big{font-size:34px;text-align:center;margin:8px 0}
input.num.ok,.fld.ok input.num{border-color:var(--good);background:var(--good-l)}
.fld.bad input.num{border-color:var(--bad);background:var(--bad-l)}
textarea.say{width:100%;min-height:120px;text-align:left;font-size:20px;padding:12px;font-weight:700}
.opts{display:grid;gap:10px;margin:12px 0}
.opt{text-align:left;background:#fff;border:3px solid var(--line);border-radius:18px;padding:12px 16px;font-size:20px;font-weight:800;cursor:pointer;color:var(--ink);font-family:inherit;box-shadow:0 4px 0 var(--line)}
.opt:hover{border-color:var(--brand)}
.opt.sel{border-color:var(--brand);background:var(--brand-l)}
.opt.ok{border-color:var(--good);background:var(--good-l)}
.opt.bad{border-color:var(--bad);background:var(--bad-l)}
.eqn{font-size:32px;text-align:center;margin:8px 0}

/* feedback */
.fb{border-radius:18px;padding:12px 16px;margin:10px 0;font-size:19px;animation:pop .25s ease}
.fb.good{background:var(--good-l);color:#0f5f37;border:2px solid #a8e8c6}
.fb.try{background:var(--warn-l);color:#7a5200;border:2px solid #ffd88a}
.fb.info{background:var(--brand-l);border:2px solid var(--line)}
.work{background:#fff;border:2px dashed #b9b2f5;border-radius:18px;padding:12px 18px;margin:10px 0}
.work h4{margin:0 0 6px;font-size:17px;color:var(--brand);text-transform:uppercase;letter-spacing:.05em}
.work ol{margin:0;padding-left:22px}
.work li{margin:6px 0;font-size:19px}
.key{background:var(--warn-l);border:3px solid #ffd88a;border-radius:22px;padding:14px 18px;margin:14px 0;font-size:20px;animation:pop .3s ease}
.key:before{content:"💡 Key idea";display:block;font-size:14px;font-weight:900;color:#9a6400;text-transform:uppercase;letter-spacing:.07em;margin-bottom:4px}
.actions{display:flex;gap:12px;justify-content:space-between;margin-top:16px;position:sticky;bottom:0;z-index:5;padding:14px 0 10px;background:linear-gradient(to bottom,rgba(255,247,234,0),#FFF7EA 38%)}
.actions .btn{flex:0 0 auto}
.readout{display:flex;gap:14px;flex-wrap:wrap;justify-content:center;font-size:26px;margin:6px 0}
.readout .box{background:var(--brand-l);border-radius:16px;padding:8px 16px;min-width:120px;text-align:center}
.readout .box small{display:block;font-size:13px;color:var(--muted);text-transform:uppercase;letter-spacing:.06em}
input[type=range]{width:100%;accent-color:var(--brand);height:36px}
.dial{display:flex;gap:12px;align-items:center}
.dial .n{font-size:34px;min-width:54px;text-align:center;color:var(--brand);font-weight:900}

/* practice grid */
.dots{display:flex;gap:8px;flex-wrap:wrap}
.dot{width:46px;height:46px;border-radius:50%;border:3px solid var(--line);background:#fff;font-weight:900;font-size:18px;cursor:pointer;color:var(--ink);font-family:inherit}
.dot.cur{border-color:var(--brand);box-shadow:0 0 0 4px #d8d3ff}
.dot.good{background:var(--good);color:#fff;border-color:var(--good-d)}
.dot.miss{background:var(--warn);color:#fff;border-color:#c88108}
.dot.ans{background:var(--brand-l);border-color:var(--brand)}
.lvl{font-size:14px;font-weight:900;color:var(--accent);text-transform:uppercase;letter-spacing:.08em}

/* ring */
.ring{--p:0;width:64px;height:64px;border-radius:50%;background:conic-gradient(var(--good) calc(var(--p)*1%),#ECE9FB 0);display:grid;place-items:center;flex:0 0 auto}
.ring span{width:46px;height:46px;border-radius:50%;background:#fff;display:grid;place-items:center;font-size:15px;font-weight:900}

/* chat drawer */
.fab{position:fixed;right:16px;bottom:16px;z-index:30;border-radius:999px;padding:12px 20px;font-size:18px}
.drawer{position:fixed;right:12px;bottom:12px;width:min(420px,calc(100vw - 24px));max-height:78vh;background:#fff;border:3px solid var(--line);border-radius:26px;box-shadow:0 20px 50px rgba(31,36,71,.25);z-index:40;display:flex;flex-direction:column;overflow:hidden}
.drawer header{display:flex;align-items:center;gap:10px;padding:10px 14px;background:var(--brand-l);font-weight:900}
.drawer .msgs{padding:12px;overflow:auto;display:flex;flex-direction:column;gap:10px;min-height:160px}
.msg{max-width:88%;padding:10px 14px;border-radius:18px;font-size:17px;white-space:pre-wrap}
.msg.zed{background:var(--brand-l);align-self:flex-start}
.msg.me{background:var(--accent-l);align-self:flex-end}
.drawer form{display:flex;gap:8px;padding:10px;border-top:2px solid var(--line)}
.drawer input{flex:1;font:inherit;font-weight:700;border:3px solid var(--line);border-radius:14px;padding:8px 12px}

/* modal and toast */
.modal{position:fixed;inset:0;background:rgba(31,36,71,.5);display:grid;place-items:center;z-index:60;padding:16px}
.modal .card{max-width:480px;width:100%}
.toast{position:fixed;left:50%;bottom:92px;transform:translateX(-50%);background:var(--ink);color:#fff;padding:10px 20px;border-radius:99px;z-index:70;font-size:17px;animation:pop .25s ease}

/* break */
.breathe{width:150px;height:150px;border-radius:50%;margin:16px auto;background:radial-gradient(circle,#9bf6ff,#2ec4b6);animation:breathe 6s ease-in-out infinite;display:grid;place-items:center;font-size:44px;color:#fff;font-weight:900}
@keyframes breathe{0%,100%{transform:scale(.7)}50%{transform:scale(1.1)}}

/* confetti */
.cf{position:fixed;width:10px;height:14px;z-index:80;pointer-events:none;animation:fall 1.4s ease-out forwards}
@keyframes fall{to{transform:translate(var(--dx),var(--dy)) rotate(var(--r));opacity:0}}

table.rep{width:100%;border-collapse:collapse;font-size:16px}
table.rep th,table.rep td{border-bottom:2px solid var(--line);padding:8px;text-align:left;vertical-align:top}
.sheetfig{margin:8px 0}
.cs h3{color:var(--brand)}
.cs .ex{background:var(--accent-l);border-radius:16px;padding:10px 14px;margin:8px 0}
.review .q{border-bottom:2px solid var(--line);padding:14px 0}
.review .q:last-child{border:0}

@media (max-width:560px){
  html,body{font-size:17px}
  h1{font-size:28px}.zed{width:68px}.bubble{font-size:19px}
  input.num{width:70px;font-size:24px}.btn{font-size:18px;padding:12px 20px}
}
@media (prefers-reduced-motion:reduce){
  *{animation:none!important;transition:none!important}
}