:root{--bg:#f3f7f5;--surface:#fff;--soft:#edf5f2;--ink:#173f3b;--muted:#6d807c;--line:#dbe7e3;--green:#206b67;--gold:#b88b3f;--goldsoft:#f7efdf;--success:#2d7a62;--shadow:0 22px 58px rgba(23,63,59,.11);--shadow-sm:0 10px 28px rgba(23,63,59,.07)}
*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;font-family:Inter,ui-sans-serif,system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;background:var(--bg);color:var(--ink);line-height:1.55}a{text-decoration:none;color:inherit}button,input,select{font:inherit}.container{max-width:1160px;margin:auto;padding:0 22px}
.nav{height:76px;display:flex;align-items:center;justify-content:space-between;gap:20px}.brand{display:flex;align-items:center;gap:10px;font-weight:950}.mark{width:39px;height:39px;border-radius:12px;background:var(--ink);color:#fff;display:grid;place-items:center;font-size:12px}.brand small{display:block;font-size:9px;color:var(--gold);letter-spacing:.13em}.links{display:flex;gap:21px;font-size:13px;font-weight:800;color:#566d68}.actions{display:flex;gap:8px;align-items:center}
.btn{border:0;border-radius:13px;padding:11px 16px;font-weight:900;cursor:pointer;display:inline-flex;align-items:center;justify-content:center;gap:7px}.primary{background:var(--ink);color:#fff}.secondary{background:#fff;border:1px solid var(--line);color:var(--ink)}.gold{background:var(--gold);color:#fff}
.page{padding:44px 0 72px}.eyebrow{font-size:10px;color:var(--gold);font-weight:950;letter-spacing:.13em;text-transform:uppercase}h1{font-size:clamp(36px,5vw,56px);line-height:1;letter-spacing:-.05em;margin:8px 0 10px}h2{letter-spacing:-.025em}.lead{color:var(--muted);font-size:15px;max-width:700px}.card{background:#fff;border:1px solid var(--line);border-radius:22px;padding:22px;box-shadow:var(--shadow-sm)}.grid2{display:grid;grid-template-columns:1fr 1fr;gap:15px}.grid3{display:grid;grid-template-columns:repeat(3,1fr);gap:13px}.grid4{display:grid;grid-template-columns:repeat(4,1fr);gap:11px}.metric{background:#fff;border:1px solid var(--line);border-radius:17px;padding:17px}.metric span{display:block;font-size:10px;color:var(--muted);font-weight:850}.metric strong{display:block;font-size:27px;margin-top:4px}.metric small{font-size:10px;color:#93a19e}
.hero{padding:72px 0;display:grid;grid-template-columns:1.05fr .95fr;gap:55px;align-items:center}.hero h1{font-size:clamp(48px,6vw,78px)}.hero p{font-size:18px;color:#5b716d}.hero-demo{background:rgba(255,255,255,.72);border:1px solid #fff;border-radius:30px;padding:14px;box-shadow:var(--shadow)}.demo-card{min-height:430px;border:1px solid var(--line);border-radius:22px;background:#fff;padding:24px;display:flex;flex-direction:column}.demo-front{font-size:34px;font-weight:950;text-align:center;margin:auto}.demo-back{font-size:29px;font-weight:950;color:var(--green);text-align:center;margin:10px 0 60px}.chip{display:inline-flex;padding:6px 9px;border-radius:999px;background:var(--soft);color:var(--green);font-size:9px;font-weight:950;text-transform:uppercase}
.learn-shell{max-width:760px;margin:auto}.learn-card{min-height:570px;background:#fff;border:1px solid var(--line);border-radius:28px;padding:25px;box-shadow:var(--shadow);display:flex;flex-direction:column;cursor:pointer}.learn-head,.row{display:flex;align-items:center;justify-content:space-between;gap:12px}.progress{height:6px;border-radius:999px;background:#e6eeeb;overflow:hidden;margin:16px 0}.progress i{display:block;height:100%;background:linear-gradient(90deg,var(--green),var(--gold))}.prompt{text-align:center;color:#84938f;font-size:14px;margin-top:20px}.front{text-align:center;font-size:40px;font-weight:950;letter-spacing:-.035em;margin:36px 0 22px}.answer-wrap{opacity:0;transform:translateY(8px);transition:.18s;text-align:center}.learn-card.revealed .answer-wrap{opacity:1;transform:none}.answer{font-size:34px;color:var(--green);font-weight:950;white-space:pre-line}.usage{margin:15px auto 0;max-width:580px;font-size:13px;color:#617571}.hint{text-align:center;color:#94a29f;font-size:11px;margin-top:auto}.ratings{display:grid;grid-template-columns:repeat(4,1fr);gap:8px;margin-top:12px}.ratings button{background:#fff;border:1px solid var(--line);padding:14px 8px;border-radius:14px;font-weight:900;color:#48615d;cursor:pointer}.ratings button:hover{transform:translateY(-1px)}
.chapter-list{display:grid;gap:10px}.chapter{background:#fff;border:1px solid var(--line);border-radius:17px;padding:17px;display:grid;grid-template-columns:70px 1fr auto;gap:15px;align-items:center}.num{font-size:11px;font-weight:950;color:var(--gold)}.chapter h3{margin:0;font-size:15px}.chapter p{margin:3px 0 0;color:var(--muted);font-size:11px}.pill{padding:5px 8px;border-radius:999px;background:var(--soft);color:var(--green);font-size:9px;font-weight:950}.pill.gold{background:var(--goldsoft);color:#876426}
.auth{min-height:calc(100vh - 76px);display:grid;place-items:center;padding:35px 18px}.auth-card{width:min(480px,100%);background:#fff;border:1px solid var(--line);border-radius:26px;padding:28px;box-shadow:var(--shadow)}.input{display:grid;gap:6px;margin-top:12px}.input label{font-size:11px;font-weight:850}.input input,.input select{border:1px solid var(--line);border-radius:12px;padding:12px 13px;outline:none}.error{background:#faeeee;color:#944848;border-radius:12px;padding:11px 13px;font-size:12px;margin-top:14px}.notice{background:var(--soft);border-radius:14px;padding:14px;color:#526b66;font-size:12px}.table{width:100%;border-collapse:collapse}.table td,.table th{padding:12px;border-bottom:1px solid var(--line);font-size:12px;text-align:left}.table th{font-size:10px;color:#8b9a97;text-transform:uppercase}
footer{padding:28px 0;color:#8b9a97;font-size:10px}
@media(max-width:850px){.links{display:none}.hero{grid-template-columns:1fr}.grid4{grid-template-columns:1fr 1fr}.grid3,.grid2{grid-template-columns:1fr}}@media(max-width:600px){.container{padding:0 15px}.nav{height:68px}.actions .secondary{display:none}.page{padding-top:28px}.front{font-size:34px}.answer{font-size:29px}.learn-card{min-height:520px;padding:19px}.chapter{grid-template-columns:52px 1fr}.chapter>.pill{grid-column:2}.ratings{gap:5px}.ratings button{font-size:11px;padding:12px 4px}}