*{box-sizing:border-box}
:root{
  --blue:#0b4db7;--blue2:#1667e8;--navy:#082b68;--ink:#17233a;--muted:#64748b;
  --line:#d8e2ef;--soft:#f5f8fc;--ok:#177245;--okbg:#edf9f2;--bad:#b42318;--badbg:#fff1ef;--warn:#845400;--warnbg:#fff7e6
}
html,body{margin:0;min-height:100%;font-family:Arial,Helvetica,sans-serif;background:#f4f7fb;color:var(--ink)}
button,a{font:inherit}.shell{min-height:100vh;display:flex;flex-direction:column}
.topbar{height:70px;background:#fff;border-bottom:1px solid #e7edf5;display:flex;align-items:center;justify-content:space-between;padding:0 28px;position:sticky;top:0;z-index:20}
.brand-wrap{display:flex;align-items:center;gap:10px}.brand-logo{height:42px;max-width:190px;object-fit:contain}.brand-fallback{font-size:28px;font-weight:900;color:var(--navy);display:none}
.home-link{margin-left:auto;text-decoration:none;color:var(--blue);font-weight:800;padding:10px 14px;border-radius:10px}.home-link:hover,.home-link:focus-visible{background:#eef5ff;outline:none}
.main{width:min(100%,1000px);margin:0 auto;padding:28px 20px 46px;flex:1}.back-row{margin-bottom:15px}.back-link{text-decoration:none;color:var(--blue);font-weight:700;font-size:14px}.back-link:hover{text-decoration:underline}
.practice-head{display:flex;align-items:flex-start;justify-content:space-between;gap:24px;margin-bottom:16px}.badge{display:inline-flex;align-items:center;background:#eaf2ff;color:var(--blue2);font-weight:900;border-radius:999px;padding:8px 12px;font-size:14px;margin-bottom:9px}
h1{font-size:clamp(26px,4vw,38px);line-height:1.12;margin:0;color:var(--navy);letter-spacing:-.5px}.standard{margin:8px 0 0;color:var(--muted);font-size:14px;line-height:1.45}.model-note{margin:5px 0 0;color:#7a889d;font-size:12px}
.score-rule{background:#fff;border:1px solid var(--line);border-radius:13px;padding:11px 14px;color:var(--muted);font-size:13px;line-height:1.45;min-width:245px}.score-rule strong{color:var(--ink)}
.progress-row{display:grid;grid-template-columns:auto 1fr auto;gap:12px;align-items:center;margin:19px 0 15px;color:var(--muted);font-size:14px;font-weight:800}.progress-track{height:9px;background:#e6edf6;border-radius:999px;overflow:hidden}.progress-fill{height:100%;background:var(--blue2);width:10%;transition:width .2s ease}
.question-card{background:#fff;border:1px solid var(--line);border-radius:18px;box-shadow:0 12px 34px rgba(17,48,96,.07);padding:clamp(22px,4vw,36px)}
.question-top{display:flex;justify-content:space-between;align-items:center;gap:12px;margin-bottom:14px}.question-label{font-size:13px;font-weight:900;color:var(--blue2);text-transform:uppercase;letter-spacing:.07em}.audio-btn{border:1px solid #cfe0f6;background:#f6faff;color:var(--blue);border-radius:9px;padding:8px 11px;font-weight:800;cursor:pointer}.audio-btn:hover{background:#edf5ff}
.question-text{font-size:clamp(22px,3vw,31px);line-height:1.3;font-weight:800;color:#162849;margin:0 0 20px}.instruction{font-size:14px;color:var(--muted);font-weight:700;margin:-8px 0 18px}
.visual{margin:8px 0 22px;overflow-x:auto}.answer-grid{display:grid;grid-template-columns:1fr 1fr;gap:12px}.answer{position:relative;border:2px solid #d6e0ec;background:#fff;color:#172a4b;border-radius:12px;padding:15px 16px 15px 52px;text-align:left;font-size:19px;font-weight:750;cursor:pointer;min-height:62px;transition:.12s ease}.answer-letter{position:absolute;left:13px;top:50%;transform:translateY(-50%);width:28px;height:28px;border-radius:50%;display:grid;place-items:center;border:2px solid #9fb5d1;font-weight:900;color:#39577d;background:#fff}.answer:hover:not(:disabled),.answer:focus-visible:not(:disabled){border-color:var(--blue2);background:#f4f8ff;outline:none}.answer.selected{border-color:var(--blue2);background:#edf4ff}.answer.selected .answer-letter{background:var(--blue2);border-color:var(--blue2);color:#fff}.answer.wrong{border-color:#e9a39d;background:var(--badbg);color:#7a271a}.answer.correct{border-color:#82c6a4;background:var(--okbg);color:#145a3d}.answer.correct .answer-letter{border-color:var(--ok);color:var(--ok)}.answer:disabled{cursor:default;opacity:.98}
.controls{display:flex;justify-content:space-between;align-items:center;gap:12px;margin-top:21px;min-height:50px}.attempt{color:var(--muted);font-weight:800;font-size:14px}.btn{border:none;border-radius:11px;padding:12px 22px;font-weight:900;cursor:pointer}.btn-primary{background:var(--blue2);color:#fff}.btn-primary:hover,.btn-primary:focus-visible{filter:brightness(.96);outline:3px solid rgba(22,103,232,.18)}.btn-secondary{background:#eef4ff;color:var(--blue)}.btn[hidden]{display:none}
.feedback{margin-top:17px;border-radius:12px;padding:13px 15px;line-height:1.5;font-size:16px;display:none}.feedback.show{display:block}.feedback.try{background:var(--warnbg);border:1px solid #eed092;color:#694600}.feedback.good{background:var(--okbg);border:1px solid #99d0b4;color:#145a3d}.feedback.explain{background:#f1f5fb;border:1px solid #c8d6e8;color:#253858}.feedback strong{display:block;margin-bottom:3px}
.result-card{background:#fff;border:1px solid var(--line);border-radius:18px;box-shadow:0 12px 34px rgba(17,48,96,.07);padding:34px;text-align:center}.result-score{font-size:64px;line-height:1;font-weight:900;color:var(--blue2);margin:14px 0 8px}.result-card h2{font-size:30px;color:var(--navy);margin:0}.result-card p{color:var(--muted);font-size:17px}.stat-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:12px;margin:24px 0}.stat{background:var(--soft);border-radius:13px;padding:16px}.stat b{display:block;color:var(--navy);font-size:24px;margin-bottom:4px}.result-actions{display:flex;justify-content:center;gap:11px;flex-wrap:wrap;margin-top:22px}.result-actions a{text-decoration:none}.saved-note{font-size:14px;color:var(--ok);font-weight:800;margin-top:15px}.storage-note{font-size:12px!important;margin-top:6px!important}
/* visual helpers */
.dot-row{display:flex;gap:7px;flex-wrap:wrap;align-items:center;padding:10px 2px}.dot{width:25px;height:25px;border-radius:50%;background:#1e70e7;display:inline-block}.dot.removed{opacity:.2;position:relative}.dot.removed:after{content:"×";position:absolute;inset:-7px 0 0;text-align:center;color:#b42318;font-size:32px;font-weight:900}
.base-ten{display:flex;align-items:flex-end;gap:8px;flex-wrap:wrap;padding:8px 0}.ten{width:22px;height:100px;border:2px solid #1767d7;background:repeating-linear-gradient(to bottom,#eaf2ff 0,#eaf2ff 8px,#bdd5fa 9px,#bdd5fa 10px);border-radius:4px}.one{width:22px;height:22px;border:2px solid #1767d7;background:#eaf2ff;border-radius:4px}
.number-line svg,.ruler svg,.clock-svg svg,.shape-svg svg,.fraction-svg svg{max-width:100%;height:auto;display:block}.number-chart{display:grid;grid-template-columns:repeat(10,42px);gap:2px;width:max-content;border:1px solid #adc3df;background:#adc3df}.number-chart span{background:#fff;padding:9px 5px;text-align:center;font-weight:800}.number-chart .hi{background:#dbeaff;color:#0b4db7}
.measure-list{display:grid;gap:10px;max-width:600px}.measure-item{display:grid;grid-template-columns:100px 1fr 44px;gap:10px;align-items:center;font-weight:800}.measure-bar{height:28px;background:#dbe9ff;border:2px solid #1667e8;border-radius:6px}.measure-value{color:#4e6381}.picto{border-collapse:collapse;min-width:360px;background:#fff}.picto th,.picto td{border:1px solid #cbd8e8;padding:10px 12px;text-align:left;font-size:17px}.picto th{background:#edf5ff;color:var(--navy)}.icons{letter-spacing:5px;font-size:22px;white-space:nowrap}.tally{font-family:ui-monospace,SFMono-Regular,Menlo,monospace;letter-spacing:2px;font-size:21px}.legend{font-size:13px;color:var(--muted);margin-top:6px;font-weight:700}.coin-row{display:flex;gap:10px;flex-wrap:wrap;align-items:center}.coin{width:52px;height:52px;border-radius:50%;border:3px solid #899ab1;background:#edf1f5;display:grid;place-items:center;font-weight:900;color:#43536a}.coin.dime{width:45px;height:45px}.coin.nickel{width:50px;height:50px}.coin.penny{background:#f1d2b4;border-color:#b87945}.bill{display:inline-flex;align-items:center;justify-content:center;width:110px;height:54px;border:3px solid #60866a;background:#eff8f1;border-radius:6px;font-weight:900;color:#315f3a;margin:4px}
.choice-visual{display:flex;align-items:center;gap:10px;min-height:36px}.shape-icon{font-size:40px;line-height:1}.mini-model{display:flex;gap:5px;align-items:flex-end}.mini-ten{width:10px;height:38px;border:1px solid #1767d7;background:#dceaff}.mini-one{width:10px;height:10px;border:1px solid #1767d7;background:#dceaff}
@media(max-width:700px){.topbar{height:62px;padding:0 13px}.brand-logo{height:37px;max-width:155px}.brand-fallback{font-size:24px}.home-link{padding:8px 10px}.main{padding:20px 13px 34px}.practice-head{display:block}.score-rule{margin-top:13px;min-width:0}.answer-grid{grid-template-columns:1fr}.answer{font-size:18px;padding:14px 14px 14px 50px}.question-card{border-radius:15px}.stat-grid{grid-template-columns:1fr}.progress-row{grid-template-columns:auto 1fr}.score-live{grid-column:1/-1;text-align:right}.question-top{align-items:flex-start}.number-chart{grid-template-columns:repeat(10,34px)}.number-chart span{padding:7px 3px;font-size:13px}}