:root{color-scheme:light;--ink:#19352e;--muted:#53645e;--paper:#f6f5ef;--green:#21614f;--line:#cdd7ce;--accent:#e5edbc;font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,'Segoe UI',sans-serif;color:var(--ink);background:var(--paper);line-height:1.65}*{box-sizing:border-box}body{margin:0}a{color:var(--green);text-underline-offset:.2em}header{max-width:1280px;margin:auto;padding:24px 32px;display:flex;align-items:center;gap:28px;border-bottom:1px solid var(--line)}header nav{display:flex;gap:22px;margin-left:auto;flex-wrap:wrap}header a{text-decoration:none}.brand{font-weight:800;letter-spacing:-.04em;font-size:22px;white-space:nowrap}.brand span{font-weight:450;letter-spacing:-.03em;font-size:16px}main{max-width:1180px;margin:auto;padding:0 32px 64px}.hero{padding:66px 0 36px;max-width:850px}.eyebrow{font-size:12px;font-weight:750;letter-spacing:.15em;color:var(--green);margin-bottom:20px}h1{font-size:clamp(34px,5vw,60px);line-height:1.14;font-weight:700;letter-spacing:-.055em;margin:0 0 24px;word-break:keep-all}h2{font-size:22px;letter-spacing:-.035em;line-height:1.35}p{margin:12px 0}.lede{font-size:19px;max-width:720px;color:var(--muted)}.cards{display:grid;grid-template-columns:repeat(3,1fr);gap:20px;margin:10px 0 58px}.card{display:flex;flex-direction:column;border:1px solid var(--line);border-radius:14px;padding:28px;text-decoration:none;color:var(--ink);background:#fff;transition:border-color .15s,transform .15s}.card:hover{border-color:var(--green);transform:translateY(-3px)}.card p{color:var(--muted);margin:0 0 32px}.card>span:last-child{margin-top:auto;font-weight:650}.number{background:var(--accent);width:42px;height:42px;border-radius:50%;display:grid;place-items:center;font-size:13px}.workspace{display:grid;grid-template-columns:minmax(260px,.85fr) minmax(0,1.15fr);border:1px solid var(--line);border-radius:16px;background:#fff;overflow:hidden;margin-bottom:24px}.controls,.result{padding:30px;min-width:0}.controls{border-right:1px solid var(--line)}.result{background:#eef2ea}.workspace h2{margin-top:0;margin-bottom:24px}label{display:block;font-weight:650;font-size:14px;margin:18px 0 6px}input,select,textarea,button{font:inherit}input:not([type=checkbox]),select,textarea{width:100%;min-width:0;border:1px solid #a9b6af;border-radius:7px;background:white;color:var(--ink);padding:10px 12px;min-height:46px}input[type=file]{padding:10px;font-size:13px}input[type=file]::file-selector-button{background:#edf2e8;color:var(--ink);border:0;border-radius:4px;padding:7px;margin-right:8px;cursor:pointer}input[type=checkbox]{width:18px;height:18px;accent-color:var(--green);flex-shrink:0}.check{display:flex;gap:10px;align-items:flex-start;font-weight:450;font-size:15px}.field-grid{display:grid;grid-template-columns:1fr 1fr;gap:16px}button,.button{border:1px solid var(--green);border-radius:7px;background:var(--green);color:white;padding:11px 17px;cursor:pointer;min-height:44px;font-weight:650;text-decoration:none}button:hover:not(:disabled){background:#164c3d}button:disabled{opacity:.48;cursor:not-allowed}.actions{display:flex;flex-wrap:wrap;gap:9px;margin-top:22px}#reset-button,#cancel-button,#print-note{color:var(--green);background:transparent}#download-button,#calibration-download,#confirm-button{margin-top:24px}.hint{font-size:13px;color:var(--muted)}.explanation{max-width:850px;margin:44px 0;padding-top:24px;border-top:1px solid var(--line)}.explanation p{color:#40564d}.feedback{padding:0 4px}.feedback:has(#error:not(:empty)){border-left:3px solid #9e3825;padding-left:16px}#status{color:var(--muted)}#error{color:#9e3825;font-weight:650}.notice{padding:20px;background:#fff1dc;border-radius:8px}.table-scroll{max-width:100%;overflow-x:auto}table{border-collapse:collapse;width:100%;text-align:left;font-size:14px;margin:18px 0}caption{text-align:left;font-weight:650;margin-bottom:10px}th,td{padding:9px 12px;border-bottom:1px solid var(--line)}#preview{display:flex;flex-wrap:wrap;gap:12px}#preview canvas{max-width:100%;height:auto;border:1px solid var(--line)}footer{max-width:1180px;margin:0 auto;padding:30px 32px 40px;border-top:1px solid var(--line);color:var(--muted);font-size:13px}footer p{font-weight:650}.skip{position:absolute;left:12px;top:-100px;background:white;padding:12px;z-index:9}.skip:focus{top:12px}:focus-visible{outline:3px solid #a56812;outline-offset:4px}.flip-diagram{display:flex;align-items:center;justify-content:center;gap:18px;padding:24px 0;margin-bottom:20px}.paper-face{position:relative;aspect-ratio:210/297;width:36%;background:white;box-shadow:0 4px 10px #15342613;border:1px solid #a2b2a5;display:flex;align-items:center;justify-content:center;flex-direction:column;font-size:14px}.paper-face strong{font-size:20px}.top-marker{position:absolute;top:12px;left:0;right:0;text-align:center;color:var(--green);font-size:13px;font-weight:750}.corner{position:absolute;bottom:10px;left:12px;color:#617765}.back-content{position:absolute;inset:0;display:flex;align-items:center;justify-content:center}.flip-diagram[data-orientation=landscape] .paper-face{aspect-ratio:297/210;width:42%}.flip-diagram[data-axis=vertical] .paper-face:before{content:'';position:absolute;inset:-8px auto -8px -6px;border-left:3px dashed var(--green)}.flip-diagram[data-axis=horizontal] .paper-face:before{content:'';position:absolute;inset:-6px -8px auto -8px;border-top:3px dashed var(--green)}.flip-diagram[data-match=false] .back-content{transform:rotate(180deg)}.axis-symbol{font-size:24px;color:var(--green)}#flip-result{padding:12px 15px;border-radius:7px;background:#dde9d5;font-weight:650}.flip-diagram[data-match=false]~#flip-result{background:#f7e6c8}@media(max-width:850px){header{flex-wrap:wrap;gap:14px;padding:18px 24px}header nav{order:3;width:100%;margin:0;font-size:14px}header>a:last-child{margin-left:auto}.cards{grid-template-columns:1fr}.card{padding:24px}.workspace{grid-template-columns:1fr}.controls{border-right:0;border-bottom:1px solid var(--line)}.hero{padding-top:42px}}@media(max-width:480px){main{padding:0 18px 40px}header{padding:18px}.brand{font-size:19px}.brand span{font-size:13px}.controls,.result{padding:22px 18px}.hero{padding-top:32px}.lede{font-size:17px}.flip-diagram{gap:12px}.paper-face strong{font-size:16px}.top-marker{top:7px;font-size:11px}footer{padding:24px 18px}.actions button{flex-grow:1}}@media(prefers-reduced-motion:reduce){*,*:before,*:after{animation:none!important;transition:none!important;scroll-behavior:auto!important}.card:hover{transform:none}}@media print{header,footer,.controls,.actions,button,.skip{display:none!important}main{padding:0;max-width:none}.hero{padding:12px 0}.workspace{display:block;break-inside:avoid}.result{background:white}.explanation{break-inside:avoid}.feedback:empty{display:none}body{background:white}}
details{border:1px solid var(--line);border-radius:12px;padding:20px;margin:28px 0}summary{cursor:pointer;font-weight:700;font-size:18px}details .workspace{margin-top:22px}details>p{max-width:800px;color:var(--muted)}
@media print{body[data-print-note]>:not(#calibration-print-note){display:none!important}#calibration-print-note{display:block}}
.preview-navigation{display:flex;align-items:center;gap:1rem;justify-content:space-between}.preview-faces{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:1rem}.preview-faces figure{margin:0;min-width:0}.preview-faces canvas{max-width:100%;height:auto;border:1px solid #94a3b8}.preview-faces figcaption{padding:.4rem;font-size:.9rem}@media(max-width:600px){.preview-faces{grid-template-columns:1fr}.preview-navigation{gap:.4rem;flex-wrap:wrap}}