:root{
  --bg:#eef5f1; --card:#ffffff; --text:#13241b; --muted:#62766a; --line:#cadcd1;
  --primary:#2f6f52; --primary2:#3c8764; --soft:#eef8f3; --good:#176b45; --bad:#a23b2d;
  --warn-bg:#fff6e6; --warn-line:#edcf84; --info-bg:#f5f1fb; --info-line:#dec9ee;
  --shadow:0 12px 28px rgba(22,50,34,.08);
}
*{box-sizing:border-box}
body{
  margin:0;font-family:Inter,system-ui,-apple-system,"Segoe UI",Arial,sans-serif;color:var(--text);
  background:linear-gradient(180deg,#ecf4ef,#f8fbfa 45%,#edf4f0);min-height:100vh
}
a{color:inherit}
.wrap{max-width:1180px;margin:auto;padding:22px}
.crumbs{font-size:13px;color:var(--muted);margin:0 0 12px}
.crumbs a{text-decoration:none}
.hero{
  background:linear-gradient(135deg,#fff,#eef8f2); border:1px solid var(--line); border-radius:24px;
  padding:24px 28px; box-shadow:var(--shadow); margin-bottom:18px
}
.hero small{display:block;font-weight:900;color:var(--primary)}
.hero h1{font-size:clamp(30px,5vw,50px);line-height:1.06;margin:7px 0 10px}
.hero p{margin:0;max-width:920px;color:var(--muted);font-size:17px;line-height:1.55}
.levelbar{display:flex;gap:12px;flex-wrap:wrap;margin:18px 0 0}
.levelbtn{
  border:2px solid var(--line); background:#fff; border-radius:15px; padding:12px 14px; min-width:220px;
  text-align:left; font-weight:900; cursor:pointer
}
.levelbtn small{display:block;color:var(--muted);font-weight:600;margin-top:3px}
.levelbtn.active{border-color:#84b59b;background:#ecf8f1;color:#184b36}
.section{margin:20px 0}
.section-title{font-size:24px;margin:0 0 12px}
.grid2,.grid3{display:grid;gap:14px}
.grid2{grid-template-columns:repeat(2,minmax(0,1fr))}
.grid3{grid-template-columns:repeat(3,minmax(0,1fr))}
.card{
  background:var(--card); border:1px solid var(--line); border-radius:18px; box-shadow:var(--shadow); padding:18px
}
.linkcard{text-decoration:none;display:block;transition:.15s transform,.15s border-color}
.linkcard:hover{transform:translateY(-2px);border-color:#8fbda4}
.card h3{margin:8px 0 6px;font-size:20px}
.card p{color:var(--muted);line-height:1.5}
.icon{font-size:34px}
.badge{display:inline-block;background:#eef8f2;color:#245a41;border-radius:999px;padding:5px 9px;font-size:12px;font-weight:900}
.topic-layout{display:grid;grid-template-columns:280px 1fr;gap:18px}
.panel{background:#fff;border:1px solid var(--line);border-radius:18px;padding:15px;height:fit-content;box-shadow:var(--shadow)}
.panel h2{font-size:16px;margin:0 0 10px}
.mode-list{display:grid;gap:8px}
.mode{
  border:1px solid var(--line); background:#fff; border-radius:12px; padding:10px 12px; text-align:left;
  font-weight:850; cursor:pointer
}
.mode small{display:block;color:var(--muted);font-weight:600;margin-top:2px}
.mode.active{background:#eaf6ef;border-color:#78ad91;color:#194d36}
.content{
  background:#fff;border:1px solid var(--line);border-radius:20px;padding:clamp(18px,3vw,30px);min-height:680px;box-shadow:var(--shadow)
}
.taskhead{display:flex;justify-content:space-between;gap:10px;align-items:center}
.pill{display:inline-block;background:#edf7f1;color:#285f45;padding:6px 10px;border-radius:999px;font-weight:900;font-size:13px}
.taskno{font-size:13px;color:var(--muted)}
.prompt{padding:16px 0}
.bigq{font-size:clamp(24px,3vw,36px);font-weight:900;line-height:1.22;margin:10px 0 18px;text-align:center}
.choicegrid{display:grid;gap:10px;max-width:860px;margin:0 auto}
.choice{
  border:2px solid #c1d1c7;background:#fff;border-radius:13px;padding:12px 14px;font-weight:800;
  font-size:16px;cursor:pointer
}
.choice:hover{border-color:#679f80;background:#f5fbf7}
.choice.selected{border-color:#306f52;background:#edf8f2}
.note{background:#eef7fb;border:1px solid #c7dfea;border-radius:13px;padding:11px 13px;margin:12px 0;line-height:1.5;color:#315c6c}
.info{background:var(--info-bg);border:1px solid var(--info-line);border-radius:14px;padding:13px 15px;line-height:1.55}
.help{background:var(--warn-bg);border:1px solid var(--warn-line);border-radius:13px;padding:11px 13px;margin:12px auto;max-width:860px;color:#6d5507;line-height:1.5}
.feedback{min-height:48px;margin-top:14px;border-radius:13px;padding:11px 14px;display:none;font-weight:850;text-align:center}
.feedback.show{display:block}
.feedback.good{background:#eaf7ef;color:var(--good)}
.feedback.bad{background:#fff0ed;color:var(--bad)}
.actions{display:flex;justify-content:space-between;gap:10px;margin-top:16px;flex-wrap:wrap}
.btn{border:1px solid var(--line);background:#fff;border-radius:11px;padding:10px 14px;font-weight:850;cursor:pointer}
.btn.primary{border:0;background:var(--primary);color:white}
.btn:disabled{opacity:.45;cursor:default}
.learn-grid{display:grid;gap:13px}
.learn-card{background:#f9fcfa;border:1px solid var(--line);border-radius:15px;padding:15px;line-height:1.55}
.learn-card h3{margin:0 0 7px}
.terms{display:flex;gap:7px;flex-wrap:wrap;margin-top:10px}
.term{background:#fff;border:1px solid #bdd2c5;border-radius:999px;padding:5px 9px;font-weight:800;font-size:13px}
.matchgrid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:10px}
.matchrow{border:1px solid var(--line);border-radius:12px;padding:11px;background:#f9fbfa}
.matchrow b{display:block;margin-bottom:6px}
.matchrow select{width:100%;padding:8px;border:1px solid #b9c9bf;border-radius:9px;background:white}
.ordergrid{display:grid;gap:10px;max-width:760px;margin:0 auto}
.orderrow{display:grid;grid-template-columns:1fr 120px;gap:10px;align-items:center;border:1px solid var(--line);border-radius:12px;padding:11px;background:#f9fbfa}
.orderrow select{padding:8px;border:1px solid #b9c9bf;border-radius:9px;background:white}
.dragwrap{max-width:900px;margin:0 auto}
.diagrambox{position:relative;background:#fbfdfc;border:1px solid var(--line);border-radius:16px;padding:12px}
.diagramcanvas{position:relative;max-width:860px;margin:0 auto}
.diagramcanvas svg{width:100%;height:auto;display:block}
.dropzone{
  position:absolute;transform:translate(-50%,-50%);min-width:120px;min-height:34px;padding:6px 10px;
  border:2px dashed #8cb59d;background:rgba(255,255,255,.95);border-radius:10px;text-align:center;
  display:flex;align-items:center;justify-content:center;font-weight:800;color:#325740
}
.dropzone.filled{border-style:solid;background:#edf8f2}
.dropzone.small{min-width:96px}
.labelbank{display:flex;gap:10px;flex-wrap:wrap;justify-content:center;margin-top:14px}
.draglabel{
  display:inline-flex;align-items:center;justify-content:center;padding:8px 12px;border-radius:999px;
  border:1px solid #9dbca8;background:#fff;font-weight:800;cursor:grab
}
.draglabel.used{opacity:.45}
.draglabel.free{opacity:1}
.legend{margin-top:10px;text-align:center;color:var(--muted);font-size:14px}
.kpi{display:flex;gap:10px;flex-wrap:wrap;margin-top:8px}
.kpi span{background:#f5f8f6;border:1px solid var(--line);border-radius:10px;padding:7px 9px;font-size:13px}
.teacherbox{background:#f8fbf9;border:1px solid var(--line);border-radius:16px;padding:15px;line-height:1.55}
.teacherbox ol{margin:8px 0 0 18px;padding:0}
.footer-note{margin-top:18px;color:var(--muted);font-size:13px;line-height:1.5}
@media(max-width:940px){.topic-layout{grid-template-columns:1fr}.panel{order:2}.content{order:1}.grid3{grid-template-columns:1fr 1fr}}
@media(max-width:620px){.grid2,.grid3,.matchgrid{grid-template-columns:1fr}.wrap{padding:12px}.hero{padding:20px}.content{padding:16px}.orderrow{grid-template-columns:1fr}.dropzone{min-width:84px;font-size:13px;padding:4px 8px}}