.exercise-shell{display:grid;grid-template-columns:265px minmax(0,1fr);gap:24px;padding:18px clamp(24px,5vw,80px) 60px}.exercise-menu{align-self:start;border:1px solid #cbbfab;border-radius:14px;background:linear-gradient(150deg,#fffdf8,#eae4d7);box-shadow:0 13px 27px rgba(37,63,57,.13);overflow:hidden}.exercise-menu>.eyebrow,.exercise-menu>h1,.exercise-menu>.menu-note{margin-left:18px;margin-right:18px}.exercise-menu h1{font-size:25px;line-height:1.05;margin-top:5px;margin-bottom:8px}.menu-note{font-size:12px;color:#657570}.exercise-menu nav{display:grid;gap:7px;padding:8px}.exercise-menu button{display:grid;grid-template-columns:38px 1fr;gap:8px;text-align:left;align-items:center;width:100%;padding:10px;border:1px solid #d6ccba;border-radius:9px;background:linear-gradient(145deg,#fffdf8,#eee8dc);color:var(--ink);box-shadow:0 3px 7px rgba(37,63,57,.07);cursor:pointer;transition:.16s}.exercise-menu button:hover{transform:translateX(3px);box-shadow:0 6px 12px rgba(37,63,57,.13)}.exercise-menu button[aria-pressed=true]{border-color:var(--ink);background:linear-gradient(135deg,var(--ink),#254c46);color:#fff;box-shadow:0 7px 14px rgba(22,48,44,.23)}.exercise-menu button>span{grid-row:1/3;display:grid;place-items:center;width:34px;height:34px;border-radius:8px;background:rgba(213,119,66,.14);font-size:10px;font-weight:600;color:var(--orange)}.exercise-menu button[aria-pressed=true]>span{background:rgba(255,255,255,.13);color:#ffd5b8}.exercise-menu button strong{font-size:12px}.exercise-menu button small{font-size:10px;opacity:.7}.practice-stage{min-width:0}.practice-top{display:flex;justify-content:space-between;align-items:center;gap:20px;margin-bottom:14px}.practice-top h2{font-size:28px;margin:4px 0}.score{display:flex;gap:8px}.score span{padding:9px 12px;border:1px solid #d0c5b2;border-radius:9px;background:#fffaf0;box-shadow:0 4px 9px rgba(37,63,57,.08);font-size:11px}.score b{font-size:16px;color:var(--green)}.problem-card{padding:clamp(24px,5vw,52px);border:1px solid #c9bda9;border-radius:16px;background:linear-gradient(145deg,#fffdf9,#f0eadf);box-shadow:0 18px 38px rgba(37,63,57,.14)}.problem-number{font-size:11px;font-weight:600;letter-spacing:.12em;color:var(--orange)}.problem-card h3{max-width:780px;font:600 clamp(23px,3vw,34px)/1.25 'Fraunces',serif;margin:12px 0 24px}.math-visual{min-height:155px;display:flex;align-items:center;justify-content:center;padding:22px;border:1px dashed #bcb19f;border-radius:13px;background:rgba(255,255,255,.55);overflow:auto}.groups{display:flex;gap:15px;flex-wrap:wrap;justify-content:center}.group-box{display:grid;grid-template-columns:repeat(var(--cols),18px);gap:7px;padding:13px;border:2px solid #78a69d;border-radius:12px;background:#e8f2ee}.dot{width:14px;height:14px;border-radius:50%;background:var(--orange);box-shadow:inset 0 -2px 2px rgba(90,43,15,.25)}.array-grid{display:grid;gap:8px;padding:18px;border-radius:13px;background:#e5efe9;box-shadow:inset 0 0 0 2px #8caea6}.number-sequence{display:flex;align-items:center;gap:5px;min-width:max-content}.number-sequence span{display:grid;place-items:center;width:40px;height:40px;border-radius:50%;background:#fff;border:2px solid var(--green);font-weight:600}.number-sequence i{width:22px;height:2px;background:var(--orange);position:relative}.number-sequence i:after{content:"";position:absolute;right:-1px;top:-4px;border-left:7px solid var(--orange);border-top:5px solid transparent;border-bottom:5px solid transparent}.bar-model{display:grid;gap:12px;width:min(560px,100%)}.bar{padding:13px 16px;border-radius:8px;background:#dfece6;border-left:5px solid var(--green);font-weight:600}.bar.long{background:#f2dfd1;border-color:var(--orange)}.fact-family{display:grid;grid-template-columns:1fr 1fr;gap:10px}.fact-family span{padding:14px 20px;border:1px solid #c9bda9;border-radius:9px;background:#fff;font-size:20px;font-weight:600}.answer-row{display:flex;gap:10px;margin-top:7px}.problem-card form{margin-top:24px}.problem-card label{font-size:12px;font-weight:600}.answer-row input{width:150px;padding:13px;border:2px solid #bfb4a2;border-radius:9px;background:white;font-size:20px}.answer-row input:focus{outline:3px solid rgba(41,95,89,.18);border-color:var(--green)}.answer-row button,.problem-actions button{padding:12px 17px;border:0;border-radius:9px;background:linear-gradient(135deg,var(--green),#1d4944);color:white;font-weight:600;cursor:pointer;box-shadow:0 6px 13px rgba(41,95,89,.22)}.feedback{min-height:46px;margin-top:16px;padding:12px 14px;border-radius:9px;display:none}.feedback.show{display:block}.feedback.correct{background:#dfeee6;color:#185643}.feedback.wrong{background:#f8e3d8;color:#8a3e22}.problem-actions{display:flex;justify-content:space-between;margin-top:12px}.problem-actions button{background:#fff;color:var(--green);border:1px solid #c9bda9;box-shadow:0 3px 7px rgba(37,63,57,.08)}.problem-actions button[data-next]{background:var(--ink);color:white}.problem-actions button:disabled{opacity:.4;cursor:not-allowed}@media(max-width:850px){.exercise-shell{grid-template-columns:1fr}.exercise-menu nav{display:flex;overflow-x:auto}.exercise-menu button{min-width:150px}.practice-top{align-items:flex-start;flex-direction:column}}@media(max-width:520px){.exercise-shell{padding-left:16px;padding-right:16px}.problem-card{padding:22px}.fact-family{grid-template-columns:1fr}.answer-row{align-items:stretch;flex-direction:column}.answer-row input{width:100%}}