:root{--ink:#151923;--muted:#617083;--paper:#f6f8fb;--panel:#fff;--line:#1519231f;--blue:#2f6df6;--green:#36a66a;--yellow:#ffd166;--shadow:0 24px 70px #1519231f}*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:86px}body{color:var(--ink);background:var(--paper);margin:0;font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,Segoe UI,sans-serif}a{color:inherit;text-decoration:none}button,input,textarea{font:inherit}button,a,input,textarea{transition:border-color .16s,box-shadow .16s,transform .16s,background .16s}button:focus-visible,a:focus-visible,input:focus-visible,textarea:focus-visible{outline-offset:3px;outline:3px solid #2f6df647}.topbar{z-index:10;border-bottom:1px solid var(--line);-webkit-backdrop-filter:blur(16px);backdrop-filter:blur(16px);background:#f6f8fbeb;justify-content:space-between;align-items:center;gap:24px;min-height:72px;padding:12px clamp(18px,5vw,64px);display:flex;position:sticky;top:0}.brand,.topbar-actions,nav{align-items:center;gap:12px;display:flex}.brand{font-weight:900}.brand-logo{object-fit:contain;border-radius:8px;width:54px;height:54px}nav a{color:var(--muted);font-weight:800}.api-badge{min-height:34px;color:var(--muted);border:1px solid var(--line);white-space:nowrap;background:#fff;border-radius:8px;align-items:center;padding:0 10px;font-size:.82rem;font-weight:900;display:inline-flex}.api-badge.active{color:#1c6b45;background:#36a66a1a;border-color:#36a66a42}.hero,.checker-section,.how-section{padding:clamp(36px,7vw,88px) clamp(18px,5vw,72px)}.hero{background:linear-gradient(135deg,#f8fbff,#eef3ff 55%,#fffdf5);grid-template-columns:minmax(0,1fr) minmax(300px,470px);align-items:center;gap:clamp(28px,6vw,72px);min-height:calc(100vh - 72px);display:grid}.hero-copy{gap:18px;display:grid}.eyebrow{color:var(--blue);letter-spacing:.08em;text-transform:uppercase;margin:0;font-size:.78rem;font-weight:900}h1,h2{color:var(--ink);letter-spacing:0;margin:0;line-height:.98}h1{max-width:860px;font-size:clamp(2.5rem,7vw,5.8rem)}h2{font-size:clamp(2rem,4vw,3.6rem)}.hero-copy p:not(.eyebrow),.section-heading p:not(.eyebrow){max-width:690px;color:var(--muted);margin:0;font-size:1.08rem;line-height:1.6}.primary-link,.primary-button,.secondary-button{cursor:pointer;border-radius:8px;justify-content:center;align-items:center;width:fit-content;min-height:48px;padding:0 18px;font-weight:900;display:inline-flex}.primary-link,.primary-button{color:#fff;background:var(--blue);border:0}.secondary-button{color:var(--ink);border:1px solid var(--line);background:#fff}.primary-link:hover,.primary-button:hover,.secondary-button:hover,.mode-card:hover{transform:translateY(-2px);box-shadow:0 14px 30px #1519231f}.hero-preview{place-items:center;min-height:520px;display:grid;position:relative}.phone-frame{aspect-ratio:.68;width:min(100%,330px);box-shadow:var(--shadow);background:#101828;border-radius:34px;place-items:center;padding:28px;display:grid;position:relative}.worksheet{background:#fff;border-radius:18px;align-content:center;gap:18px;width:100%;height:100%;padding:28px;display:grid;transform:rotate(-2deg)}.worksheet strong{color:var(--ink);font-size:1.55rem}.paper-line{background:#dfe7f3;border-radius:999px;height:10px;display:block}.paper-line.short{width:68%}.scan-bar{background:var(--green);border-radius:999px;height:4px;animation:2.4s ease-in-out infinite scan;position:absolute;top:42%;left:34px;right:34px;box-shadow:0 0 24px #36a66ae6}@keyframes scan{0%,to{transform:translateY(-100px)}50%{transform:translateY(120px)}}.answer-chip{color:var(--ink);background:var(--yellow);box-shadow:var(--shadow);border:1px solid #15192314;border-radius:8px;padding:14px 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p{max-width:360px;color:var(--muted);margin:0;line-height:1.45}.capture-actions{z-index:1;flex-wrap:wrap;justify-content:center;gap:10px;display:flex;position:relative}.capture-button{color:#fff;background:var(--blue);border:1px solid var(--blue);cursor:pointer;border-radius:8px;justify-content:center;align-items:center;min-height:46px;padding:0 16px;font-weight:900;display:inline-flex}.capture-button.secondary{color:var(--ink);border-color:var(--line);background:#fff}.homework-preview{gap:8px;width:min(100%,420px);margin:4px 0 0;display:grid}.homework-preview[hidden]{display:none}.homework-preview img{object-fit:contain;border:1px solid var(--line);background:#fff;border-radius:8px;width:100%;max-height:320px}.homework-preview figcaption{color:var(--muted);font-size:.86rem;font-weight:800}.scan-summary{text-align:left;background:#fff;border:1px solid #2f6df62e;border-radius:8px;gap:10px;width:min(100%,420px);padding:14px;display:grid}.scan-summary[hidden]{display:none}.scan-summary 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p{color:var(--muted);margin:0;font-size:.9rem;line-height:1.4}.drop-visual{border:1px solid var(--line);background:#fff;border-radius:8px;gap:8px;width:120px;padding:16px;display:grid}.drop-visual span{background:#dfe7f3;border-radius:999px;height:9px}textarea{width:100%;min-height:132px;color:var(--ink);border:1px solid var(--line);resize:vertical;background:#f8fafc;border-radius:8px;padding:14px}.example-row{flex-wrap:wrap;gap:8px;display:flex}.example-chip{min-height:36px;color:var(--ink);border:1px solid var(--line);cursor:pointer;background:#fff;border-radius:8px;padding:0 12px;font-size:.9rem;font-weight:900}.example-chip:hover{border-color:#2f6df66b;transform:translateY(-1px);box-shadow:0 10px 20px #15192314}.mode-panel{gap:10px;padding:14px;display:grid}.mode-card{min-height:112px;color:var(--ink);text-align:left;border:1px solid var(--line);cursor:pointer;background:#fff;border-radius:8px;grid-template-columns:auto 1fr;gap:6px 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span{color:var(--blue);font-weight:900}.how-grid strong{font-size:1.2rem}.how-grid p{color:var(--muted);margin:0;line-height:1.45}@media (max-width:880px){.hero,.checker-shell,.result-panel,.how-grid{grid-template-columns:1fr}.hero{min-height:auto}.hero-preview{min-height:420px}nav{display:none}}@media (max-width:560px){.topbar{min-height:64px}.brand span:last-child{max-width:180px;line-height:1.05}.api-badge{text-overflow:ellipsis;max-width:140px;overflow:hidden}.primary-link,.primary-button,.secondary-button{width:100%}}