:root{--ink:#0b1220;--navy:#152238;--navy-2:#1d2f4a;--paper:#f3eee4;--paper-2:#e9e1d2;--rule:#d3c7b4;--copper:#c17a3a;--copper-2:#e09a4f;--moss:#2c6a4e;--moss-2:#d7efe4;--rose:#9c3535;--rose-2:#f6d6d2;--text:#1b1712;--muted:#6d6459;--white:#fffdf8;--shadow:0 18px 50px #0b122029;--sans:"IBM Plex Sans", "Segoe UI", sans-serif;--serif:"IBM Plex Serif", "Times New Roman", serif}*{box-sizing:border-box}html,body,#root{min-height:100%}html,body{overflow-x:hidden}body{color:var(--text);background:radial-gradient(1200px 500px at 10% -10%, #24385a 0%, transparent 55%), var(--ink);font-family:var(--sans);margin:0;line-height:1.5}button,input{font:inherit}a{color:inherit}.shell{flex-direction:column;min-height:100vh;display:flex}.topbar{color:var(--paper);-webkit-backdrop-filter:blur(10px);backdrop-filter:blur(10px);z-index:20;background:#0b1220e0;border-bottom:1px solid #e8d1a824;justify-content:space-between;align-items:center;gap:16px;padding:14px 22px;display:flex;position:sticky;top:0}.brand{align-items:baseline;gap:10px;text-decoration:none;display:flex}.brand em{font-family:var(--serif);color:var(--copper-2);font-size:1.35rem;font-style:italic}.brand span{letter-spacing:.14em;text-transform:uppercase;color:#c9bead;font-size:.78rem}.nav-actions{align-items:center;gap:10px;display:flex}.user-chip{color:#d8d0c3;font-size:.88rem}.btn{appearance:none;cursor:pointer;border:1px solid #0000;border-radius:999px;justify-content:center;align-items:center;gap:8px;padding:10px 16px;font-weight:500;text-decoration:none;transition:transform .15s,background .15s,border-color .15s;display:inline-flex}.btn:hover{transform:translateY(-1px)}.btn:disabled{opacity:.5;cursor:not-allowed;transform:none}.btn-copper{background:var(--copper);color:#fff8ee}.btn-ghost{color:var(--paper);background:0 0;border-color:#f3eee438}.btn-ink{background:var(--navy);color:var(--paper)}.btn-paper{background:var(--white);color:var(--navy);border-color:var(--rule)}.btn-wide{width:100%}.page{flex:1;width:min(1120px,100% - 32px);margin:0 auto;padding:36px 0 72px}.hero{color:var(--paper);grid-template-columns:1.15fr .85fr;align-items:start;gap:36px;padding:28px 0 24px;display:grid}.hero h1{font-family:var(--serif);margin:0 0 16px;font-size:clamp(2.6rem,6vw,4.6rem);font-weight:600;line-height:.95}.hero p{color:#d7cfc2;max-width:38rem;font-size:1.08rem}.hero-card{background:var(--paper);color:var(--text);box-shadow:var(--shadow);border-radius:22px;padding:22px}.stat-row{grid-template-columns:repeat(3,1fr);gap:10px;margin-top:18px;display:grid}.stat{background:var(--paper-2);border-radius:14px;padding:12px}.stat b{font-family:var(--serif);font-size:1.4rem;display:block}.stat span{color:var(--muted);letter-spacing:.04em;text-transform:uppercase;font-size:.78rem}.paper-panel{background:var(--paper);color:var(--text);box-shadow:var(--shadow);border-radius:22px;padding:28px}.grid-2{grid-template-columns:1fr 1fr;gap:18px;display:grid}.domain-grid{grid-template-columns:1fr 1fr;gap:16px;display:grid}.domain-card,.missed-card{background:var(--white);border:1px solid var(--rule);border-radius:18px;min-height:180px;padding:20px;text-decoration:none;transition:transform .16s,border-color .16s;display:block}.domain-card:hover,.missed-card:hover{border-color:var(--copper);transform:translateY(-3px)}.domain-card h3,.missed-card h3{font-family:var(--serif);margin:0 0 8px;font-size:1.35rem}.progress-track{background:var(--paper-2);border-radius:99px;height:8px;margin:14px 0 8px;overflow:hidden}.progress-fill{background:linear-gradient(90deg, var(--copper), var(--copper-2));height:100%}.meta{color:var(--muted);font-size:.9rem}.skill-list{flex-wrap:wrap;gap:8px;margin-top:14px;display:flex}.skill-chip{border:1px solid var(--rule);background:var(--paper);color:var(--navy);border-radius:999px;padding:6px 10px;font-size:.78rem;text-decoration:none}.skill-chip:hover{border-color:var(--copper)}.form{gap:14px;display:grid}label{gap:6px;font-size:.9rem;font-weight:500;display:grid}input[type=text],input[type=password]{border:1px solid var(--rule);background:var(--white);border-radius:12px;padding:12px 14px}input:focus{border-color:var(--copper);outline:2px solid #c17a3a59}.field-error,.banner-error{color:var(--rose);font-size:.88rem}.banner-error,.banner-ok{border-radius:12px;padding:10px 12px}.banner-error{background:var(--rose-2)}.banner-ok{background:var(--moss-2);color:var(--moss)}.top-practice{color:var(--paper);justify-content:space-between;align-items:flex-end;gap:16px;min-width:0;margin-bottom:16px;display:flex}.top-practice-copy{min-width:0}.top-practice-crumb{color:#c9bead;overflow-wrap:anywhere}.top-practice-crumb a{color:inherit}.top-practice h1{font-family:var(--serif);overflow-wrap:anywhere;margin:4px 0 0;font-size:clamp(1.35rem,3vw,1.8rem)}.practice-layout{grid-template-columns:minmax(0,1fr) minmax(260px,360px);align-items:start;gap:18px;min-width:0;display:grid}.question-sheet{background:var(--white);border:1px solid var(--rule);min-width:0;min-height:420px;box-shadow:var(--shadow);border-radius:20px;padding:28px 28px 22px;overflow-x:auto}.question-kicker{color:var(--muted);letter-spacing:.04em;text-transform:uppercase;justify-content:space-between;gap:12px;margin-bottom:16px;font-size:.82rem;display:flex}.math-html,.math-html p{font-family:var(--serif);font-size:1.12rem}.math-html img{max-width:100%;height:auto}.math-html .sr-only{clip:rect(0,0,0,0);width:1px;height:1px;position:absolute;overflow:hidden}.math-html:has(mjx-container) math{display:none!important}.math-html mjx-assistive-mml{display:none!important}.math-html table{border-collapse:collapse;margin:12px 0}.math-html td,.math-html th{border:1px solid var(--rule);padding:6px 8px}.choices{gap:10px;margin:22px 0 8px;display:grid}.choice{text-align:left;border:1px solid var(--rule);background:var(--paper);cursor:pointer;border-radius:14px;grid-template-columns:28px 1fr;align-items:start;gap:10px;padding:12px 14px;display:grid}.choice.selected{border-color:var(--copper);background:#f7ead8}.choice.right{border-color:var(--moss);background:var(--moss-2)}.choice.wrong{border-color:var(--rose);background:var(--rose-2)}.choice-letter{background:var(--navy);width:28px;height:28px;color:var(--paper);border-radius:50%;place-items:center;font-size:.82rem;display:grid}.spr-row{gap:10px;margin:20px 0;display:flex}.spr-row input{flex:1}.timer{font-variant-numeric:tabular-nums;font-family:var(--serif);text-align:right;min-width:5.5rem;font-size:1.35rem}.timer.warn{color:var(--copper-2)}.timer.over{color:#ffb4a8}.desmos-panel{background:var(--navy-2);color:var(--paper);box-shadow:var(--shadow);border-radius:20px;position:sticky;top:84px;overflow:hidden}.desmos-head{border-bottom:1px solid #f3eee414;justify-content:space-between;align-items:center;padding:12px 14px;display:flex}.seg{gap:6px;display:flex}.seg button{color:#c9bead;cursor:pointer;background:0 0;border:0;border-radius:8px;padding:6px 8px}.seg button.on{background:var(--copper);color:#fff}.desmos-panel iframe{background:#fff;border:0;width:100%;height:520px}.reveal{border-top:1px dashed var(--rule);margin-top:18px;padding-top:16px}.reveal h4{font-family:var(--serif);margin:0 0 8px}.empty{text-align:center;padding:48px 16px}.empty h2{font-family:var(--serif)}.auth-wrap{width:min(460px,100%);margin:48px auto}@media (width<=900px){.hero,.practice-layout,.domain-grid,.grid-2{grid-template-columns:1fr}.desmos-panel{position:static}.desmos-panel iframe{height:380px}}