:root{color:#17211f;font-synthesis:none;text-rendering:optimizelegibility;background:#f5f3ed;font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif}*{box-sizing:border-box}body{min-width:320px;min-height:100vh;margin:0}button,input{font:inherit}button{cursor:pointer}.app-shell{width:min(1180px,100% - 32px);margin:0 auto;padding:32px 0 40px}.hero-panel{background:linear-gradient(135deg,#136f6324,#0000 42%),linear-gradient(90deg,#fbfaf7 0%,#e9f0ec 100%);border:1px solid #d8d3c8;border-radius:8px;grid-template-columns:minmax(0,1fr) 360px;align-items:end;gap:28px;padding:34px;display:grid}.eyebrow{color:#136f63;letter-spacing:.08em;text-transform:uppercase;margin:0 0 8px;font-size:.76rem;font-weight:800}h1,h2,p{margin-top:0}h1{letter-spacing:0;max-width:820px;margin-bottom:14px;font-size:clamp(2.25rem,5vw,4.9rem);line-height:.96}h2{letter-spacing:0;margin-bottom:0;font-size:1.45rem}.intro{color:#52615e;max-width:690px;margin-bottom:0;font-size:1.05rem;line-height:1.6}.progress-grid{grid-template-columns:repeat(3,1fr);gap:10px;display:grid}.progress-grid div{background:#ffffffc7;border:1px solid #d6ddd9;border-radius:8px;min-height:96px;padding:16px}.progress-grid span{margin-bottom:6px;font-size:2rem;font-weight:900;display:block}.progress-grid p{color:#64706e;text-transform:uppercase;margin-bottom:0;font-size:.82rem;font-weight:700}.skill-strip{grid-template-columns:repeat(5,minmax(0,1fr));gap:12px;margin:20px 0;display:grid}.skill-card{color:#17211f;text-align:left;background:#fffdf8;border:1px solid #d8d3c8;border-radius:8px;align-items:center;gap:12px;min-height:92px;padding:14px;transition:border-color .16s,box-shadow .16s,transform .16s;display:flex}.skill-card:hover,.skill-card.active{border-color:var(--accent);transform:translateY(-2px);box-shadow:0 12px 30px #2a32301f}.skill-icon{background:color-mix(in srgb, var(--accent) 15%, white);width:42px;height:42px;color:var(--accent);border-radius:8px;flex:0 0 42px;place-items:center;display:grid}.skill-card strong,.skill-card small{display:block}.skill-card strong{margin-bottom:4px;font-size:.96rem}.skill-card small{color:#65726f;font-size:.8rem;line-height:1.35}.workspace-grid{grid-template-columns:minmax(0,1.16fr) minmax(340px,.84fr);gap:20px;display:grid}.practice-panel,.graph-panel{background:#fffdf8;border:1px solid #d8d3c8;border-radius:8px;padding:24px}.section-heading{justify-content:space-between;align-items:center;gap:16px;margin-bottom:18px;display:flex}.problem-box{background:#edf6f2;border:1px solid #cfe3db;border-radius:8px;align-items:center;min-height:122px;padding:22px;display:grid}.problem-box p{margin-bottom:0;font-size:1.35rem;font-weight:800;line-height:1.35}.answer-row{margin-top:18px}.answer-row label{color:#52615e;margin-bottom:8px;font-size:.86rem;font-weight:800;display:block}.answer-row div{gap:10px;display:flex}.answer-row input{color:#17211f;background:#fff;border:1px solid #c7d0cc;border-radius:8px;width:100%;min-height:48px;padding:0 14px}.answer-row button,.tool-row button{border:0;border-radius:8px;min-height:48px;font-weight:800}.answer-row button{color:#fff;background:#136f63;min-width:104px}.feedback{border-radius:8px;align-items:center;gap:10px;margin-top:14px;padding:13px 14px;font-weight:800;display:flex}.feedback.correct{color:#14623c;background:#e7f6ed}.feedback.incorrect{color:#9b2822;background:#fbebe9}.tool-row{grid-template-columns:repeat(3,1fr);gap:10px;margin:16px 0;display:grid}.tool-row button{color:#26332f;background:#efe9dd;justify-content:center;align-items:center;gap:8px;padding:0 12px;display:inline-flex}.hint-box,.steps-box{background:#f8f3e9;border:1px solid #e1d7c5;border-radius:8px;padding:16px}.hint-box p{color:#52615e;margin:6px 0 0;line-height:1.55}.steps-box{margin-top:12px}.steps-box ol{color:#52615e;margin:10px 0 0;padding-left:22px;line-height:1.65}.graph-card{aspect-ratio:1;background:#fbfaf7;border:1px solid #cbd8d4;border-radius:8px;overflow:hidden}.graph-card svg{width:100%;height:100%;display:block}.slider-group{margin-top:18px}.slider-group label{color:#52615e;justify-content:space-between;margin-bottom:8px;font-weight:800;display:flex}.slider-group label strong{color:#17211f}.slider-group input{accent-color:#136f63;width:100%}.graph-note{color:#52615e;background:#edf6f2;border-radius:8px;align-items:flex-start;gap:8px;margin-top:18px;padding:12px;display:flex}.graph-note p{margin-bottom:0;line-height:1.45}@media (width<=980px){.hero-panel,.workspace-grid{grid-template-columns:1fr}.skill-strip{grid-template-columns:repeat(2,minmax(0,1fr))}}@media (width<=620px){.app-shell{width:min(100% - 20px,1180px);padding-top:10px}.hero-panel,.practice-panel,.graph-panel{padding:18px}.progress-grid,.skill-strip,.tool-row{grid-template-columns:1fr}.answer-row div{flex-direction:column}.answer-row button{width:100%}h1{font-size:2.25rem;line-height:1}}