:root{color:#19312c;--green:#0f5f54;--gold:#e9b949;--surface:#fff;--muted:#5f706b;--border:#d9e4df;background:#f7faf8;font-family:Inter,system-ui,sans-serif}*{box-sizing:border-box}body{min-width:320px;margin:0}a{color:inherit}.app-shell{min-height:100vh}header{background:var(--surface);border-bottom:1px solid var(--border);justify-content:space-between;align-items:center;height:68px;padding:0 5vw;display:flex}.brand{color:var(--green);font-size:1.2rem;font-weight:800;text-decoration:none}.wide-nav{align-items:center;gap:8px;display:flex}.wide-nav a{border-radius:10px;padding:12px 14px;text-decoration:none}.wide-nav a.active{color:var(--green);background:#e7f1ed;font-weight:700}main{width:min(1100px,100%);margin:auto;padding:48px max(20px,5vw) 96px}h1{margin:0 0 16px;font-size:clamp(2.2rem,6vw,4.3rem);line-height:1.05}h2{margin-top:46px}h3{margin-top:0}p{line-height:1.6}.hero{max-width:720px}.eyebrow{color:var(--green);letter-spacing:.1em;text-transform:uppercase;font-size:.8rem;font-weight:800}.actions{flex-wrap:wrap;gap:12px;margin-top:28px;display:flex}.button{border-radius:10px;justify-content:center;align-items:center;min-height:48px;padding:12px 20px;font-weight:700;text-decoration:none;display:inline-flex}.primary{background:var(--green);color:#fff}.secondary{color:var(--green);background:#e7f1ed}.cards,.metrics{grid-template-columns:repeat(2,minmax(0,1fr));gap:16px;display:grid}.card,.page-card,.metrics>div{background:var(--surface);border:1px solid var(--border);border-radius:16px;padding:24px}.metrics{grid-template-columns:repeat(3,minmax(0,1fr))}.metrics strong{color:var(--green);font-size:2rem;display:block}.metrics span{color:var(--muted);font-size:.9rem}.bottom-nav{display:none}.rich-content img{border-radius:12px;max-width:100%;height:auto;display:block}.rich-content figure{margin:20px 0}.rich-content figcaption{color:var(--muted);margin-top:6px;font-size:.9rem}.rich-content .katex-display{padding:4px;overflow:auto hidden}@media (width<=640px){header{height:60px;padding:0 20px}.wide-nav{display:none}main{padding-top:32px}.cards,.metrics{grid-template-columns:1fr}.bottom-nav{z-index:2;background:var(--surface);border-top:1px solid var(--border);grid-template-columns:repeat(4,1fr);height:72px;display:grid;position:fixed;bottom:0;left:0;right:0}.bottom-nav a{min-width:0;color:var(--muted);flex-direction:column;justify-content:center;align-items:center;gap:3px;font-size:.7rem;font-weight:700;text-decoration:none;display:flex}.bottom-nav a.active{color:var(--green)}.bottom-nav span{font-size:1.25rem}}.source-modes{gap:12px;margin-top:24px;display:grid}.source-mode{cursor:pointer;border:1px solid var(--border);border-radius:12px;align-items:flex-start;gap:14px;padding:16px;display:flex}.source-mode.selected{border-color:var(--green);background:#e7f1ed}.source-mode input{width:20px;height:20px;accent-color:var(--green);flex:none}.source-mode small{color:var(--muted);margin-top:4px;line-height:1.45;display:block}.notice{border-left:4px solid var(--gold);background:#fff8df;border-radius:8px;margin-top:24px;padding:18px}button{min-height:48px;font:inherit;border:0;border-radius:10px;padding:12px 20px;font-weight:700}button:disabled{color:#6d6d6d;cursor:not-allowed}.source-badge{color:#765500;background:#fff0bd;border-radius:999px;padding:5px 9px;font-size:.78rem;font-weight:800;display:inline-flex}.marked-list{gap:12px;margin:24px 0 0;padding:0;list-style:none;display:grid}.marked-list a{border:1px solid var(--border);border-radius:12px;gap:4px;padding:16px;text-decoration:none;display:grid}.marked-list span{color:var(--muted);font-size:.9rem}.page-card label{gap:6px;margin-top:16px;font-weight:700;display:grid}select,input{border:1px solid var(--border);width:100%;max-width:520px;min-height:44px;font:inherit;border-radius:8px;padding:8px 10px}.image-fallback{color:#765500;border:1px dashed #a87d16;border-radius:12px;padding:16px}.source-reference{border:1px solid var(--border);border-radius:12px;margin-top:20px;padding:12px}.source-reference summary{cursor:pointer;font-weight:800}.source-reference-image{margin:16px 0}.image-preview-trigger{cursor:zoom-in;background:0 0;border:0;border-radius:12px;width:100%;min-height:0;padding:0;overflow:hidden}.image-preview-trigger img{width:100%;height:auto;display:block}.image-modal-backdrop{z-index:20;background:#000000b3;place-items:center;padding:20px;display:grid;position:fixed;inset:0}.image-modal{background:var(--surface);border-radius:14px;width:min(100%,1000px);max-height:90vh;padding:16px;overflow:auto}.image-modal img{width:100%;height:auto;display:block}.image-modal-close{margin-bottom:12px}button:focus-visible,a:focus-visible,summary:focus-visible,input:focus-visible,select:focus-visible{outline:3px solid var(--gold);outline-offset:3px}.answer-options{border:0;gap:10px;min-width:0;margin:24px 0;padding:0;display:grid}.answer-options legend{margin-bottom:10px;font-weight:800}.page-card .answer{border:1px solid var(--border);background:var(--surface);cursor:pointer;border-radius:12px;align-items:flex-start;gap:12px;width:100%;min-width:0;min-height:0;margin:0;padding:14px;font-weight:400;display:flex}.answer input{width:20px;height:20px;min-height:0;accent-color:var(--green);flex:none;margin:2px 0 0;padding:0}.answer-content{flex:auto;min-width:0}.answer-content .rich-content>:first-child{margin-top:0}.answer-content .rich-content>:last-child{margin-bottom:0}.answer-content .katex-display{margin:0;padding:0;overflow-x:auto}.answer-selected{border-color:var(--green)!important;background:#e7f1ed!important}.answer-correct{color:#0b6131;background:#e7f7ed!important;border-color:#198754!important}.answer-correct input{accent-color:#198754}.answer-incorrect{color:#a12626;background:#fdeaea!important;border-color:#cf3e3e!important}.answer-incorrect input{accent-color:#cf3e3e}.answer-status{flex:none;font-size:1.25rem;font-weight:900;line-height:1.2}.feedback.correct{color:#0b6131;background:#e7f7ed;border:1px solid #198754;border-radius:12px;padding:16px}.feedback.wrong{color:#a12626;background:#fdeaea;border:1px solid #cf3e3e;border-radius:12px;padding:16px}.feedback .rich-content{color:#19312c}.visually-hidden{clip:rect(0,0,0,0);white-space:nowrap;border:0;width:1px;height:1px;margin:-1px;padding:0;position:absolute;overflow:hidden}