:root{color:#173a36;font-synthesis:none;--green:#267f68;--green-dark:#1d6655;--soft:#eaf5ef;--cream:#f8f5ed;--line:#dce7e1;--muted:#71817c;--danger:#bf5b52;background:#e9efeb;font-family:-apple-system,BlinkMacSystemFont,Segoe UI,PingFang SC,Microsoft YaHei,sans-serif}*{box-sizing:border-box}body{min-width:900px;margin:0}button{font:inherit}.app-shell{background:var(--cream);border:1px solid #d9e2dc;border-radius:30px;width:min(1194px,100vw - 28px);height:min(820px,100vh - 24px);min-height:690px;margin:12px auto;overflow:hidden;box-shadow:0 18px 52px #1a41361f}.topbar{border-bottom:1px solid var(--line);background:#ffffffed;align-items:center;gap:16px;height:70px;padding:0 30px;display:flex}.brand{font-size:21px;font-weight:900}.brand span{color:var(--green)}.crumb{color:var(--muted);font-size:14px}.accent-control{border:1px solid var(--line);height:42px;color:var(--green-dark);cursor:pointer;background:#fff;border-radius:12px;margin-left:auto;padding:0 16px;font-weight:800}.screen{height:calc(100% - 70px);padding:28px 36px}.fade{animation:.2s ease-out fade}@keyframes fade{0%{opacity:.35}to{opacity:1}}.loading{place-items:center;min-height:100vh;display:grid}.home-head{justify-content:space-between;align-items:end;margin-bottom:22px;display:flex}.home-head h1{margin:0 0 7px;font-size:31px}.home-head p,.lesson-card p{color:var(--muted);margin:0}.review-all{background:var(--soft);height:44px;color:var(--green-dark);border:0;border-radius:12px;padding:0 18px;font-weight:800}.lesson-grid{grid-template-columns:repeat(3,1fr);gap:17px;max-height:calc(100% - 80px);padding:2px;display:grid;overflow:auto}.collection-tabs{flex-wrap:wrap;gap:10px;margin:0 0 22px;display:flex}.collection-tabs button{color:#466258;font:inherit;cursor:pointer;background:#fff;border:1px solid #c7d5d0;border-radius:999px;padding:9px 14px}.collection-tabs button.active{color:#fff;background:#2f6f5e;border-color:#2f6f5e}.lesson-card{border:1px solid var(--line);background:#fff;border-radius:19px;padding:20px;box-shadow:0 7px 22px #1e473c0f}.lesson-top,.lesson-actions{justify-content:space-between;align-items:center;display:flex}.lesson-top>span{background:var(--soft);width:43px;height:43px;color:var(--green);border-radius:13px;place-items:center;font-weight:900;display:grid}.lesson-top small{color:var(--muted)}.lesson-card h2{margin:16px 0 5px}.mini-track,.progress-track{background:#e2ebe6;border-radius:99px;height:7px;overflow:hidden}.mini-track{margin:18px 0 12px}.mini-track i,.progress-track i{background:var(--green);height:100%;display:block}.lesson-actions button{cursor:pointer;border-radius:11px;height:40px;font-weight:800}.review-lesson{color:var(--green-dark);background:0 0;border:0}.review-lesson:disabled{color:#a6b1ad}.start{background:var(--green);color:#fff;border:0;padding:0 17px}.learning-meta{color:var(--muted);justify-content:space-between;font-size:20px;display:flex}.back{color:var(--green-dark);cursor:pointer;background:0 0;border:0;font-size:20px;font-weight:800}.progress-track{height:6px;margin:10px 0 16px}.learning-card{border:1px solid var(--line);background:#fff;border-radius:24px;grid-template-columns:40% 60%;height:calc(100% - 52px);display:grid;overflow:hidden;box-shadow:0 12px 36px #183a3014}.scene{background:#dcebe3;position:relative;overflow:hidden}.scene img{object-fit:cover;width:100%;height:100%}.scene span{color:#4f6760;background:#ffffffe8;border-radius:10px;padding:8px 11px;font-size:12px;font-weight:750;position:absolute;bottom:18px;left:18px}.guess-panel,.reveal-panel{flex-direction:column;min-height:0;padding:26px 34px;display:flex;overflow:auto}.prompt{color:var(--green);margin-bottom:7px;font-size:13px;font-weight:800}.guess-panel h1,.reveal-panel h1{letter-spacing:-1.4px;margin:0;font-size:42px;line-height:1.05}.phonetic{color:var(--muted);align-items:center;gap:12px;margin-top:9px;font-size:18px;display:flex}.phonetic button{background:var(--green);color:#fff;cursor:pointer;border:0;border-radius:50%;width:44px;height:44px}.guess-panel>p{color:#506862;margin:15px 0 11px;font-size:14px}.answers{grid-template-columns:1fr 1fr;gap:12px;display:grid}.answers button{border:1.5px solid var(--line);text-align:left;color:#2c4942;cursor:pointer;background:#fbfcfb;border-radius:14px;height:122px;padding:0 22px;font-size:17px;font-weight:750}.answers button b{background:var(--soft);width:29px;height:29px;color:var(--green);border-radius:8px;place-items:center;margin-right:12px;display:inline-grid}.answers button.wrong{color:#a64b44;background:#fff1ef;border-color:#d88780}.answers button.correct{color:#17654e;background:#eaf8f1;border-color:#62aa8f}.feedback{min-height:25px;color:var(--danger);margin-top:9px;font-size:14px;font-weight:750}.open-reveal{background:var(--green);color:#fff;cursor:pointer;border:0;border-radius:13px;width:100%;min-height:54px;margin-top:auto;font-weight:850}.reveal-title{align-items:start;display:flex}.reveal-title span{background:var(--soft);color:var(--green-dark);border-radius:8px;margin-left:auto;padding:7px 10px;font-size:12px;font-weight:850}.meaning{color:var(--green-dark);margin-top:16px;font-size:18px;font-weight:850}.example{background:#f5f8f6;border-radius:14px;margin-top:14px;padding:15px 17px}.example>div{align-items:center;gap:12px;display:flex}.example strong{font-size:19px;line-height:1.55}.example button{width:40px;height:40px;color:var(--green);background:#fff;border:1px solid #cde1d8;border-radius:10px;flex:0 0 40px;margin-left:auto}.example p{color:var(--muted);margin:7px 0 0;font-size:16px;line-height:1.55}.decision{gap:12px;margin-top:auto;padding-top:18px;display:flex}.decision button{cursor:pointer;border-radius:13px;height:54px;font-weight:850}.decision button:first-child{border:1px solid var(--line);color:#596c67;background:#eef2ef;flex:1}.decision button:last-child{background:var(--green);color:#fff;border:0;flex:1.35}.reveal-panel>small{color:var(--green);order:-1;margin-bottom:8px;font-weight:800}.completion{text-align:center;max-width:860px;margin:50px auto}.complete-mark{background:var(--green);color:#fff;border-radius:24px;place-items:center;width:80px;height:80px;margin:auto;font-size:38px;display:grid}.completion h1{font-size:34px}.stats{grid-template-columns:repeat(4,1fr);gap:14px;display:grid}.stats div{border:1px solid var(--line);background:#fff;border-radius:17px;padding:24px}.stats b{color:var(--green);font-size:30px;display:block}.stats span{color:var(--muted)}.complete-actions{justify-content:center;gap:12px;margin-top:26px;display:flex}.complete-actions button{border:1px solid var(--line);border-radius:13px;height:50px;padding:0 24px;font-weight:800}.complete-actions button:last-child{background:var(--green);color:#fff;border:0}@media (height<=720px){.app-shell{min-height:640px}.screen{padding:18px 30px}.guess-panel,.reveal-panel{padding:18px 28px}.guess-panel h1,.reveal-panel h1{font-size:36px}.lesson-grid{max-height:500px}}