:root{color-scheme:light;--ink:#203b49;--muted:#76868c;--teal:#2a786e;--navy:#153b4b;--line:#e4e8e5;--paper:#f7f8f4;--orange:#dd8256;--font-size:27px}*{box-sizing:border-box}body{margin:0;color:var(--ink);background:var(--paper);font-family:-apple-system,BlinkMacSystemFont,"Segoe UI","Microsoft YaHei",sans-serif}button,input,select{font:inherit}button{cursor:pointer;color:inherit}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible{outline:3px solid #dcaa77;outline-offset:4px}button{border:0;background:none}button:disabled{opacity:.35;cursor:default}svg{width:22px;height:22px;flex-shrink:0}button svg{pointer-events:none}a{text-decoration:none;color:inherit}.topbar{height:91px;border-bottom:1px solid var(--line);padding:0 5%;background:#fff;display:flex;align-items:center;justify-content:space-between}.brand{display:flex;align-items:center;gap:13px;font-family:Georgia,serif;font-size:25px;letter-spacing:-.7px}.brand-icon{height:44px;width:44px;display:grid;place-items:center;border-radius:14px;background:var(--navy);color:#fff}.brand-icon svg{width:25px;height:25px}.brand-sub{display:block;font:10px -apple-system,BlinkMacSystemFont,sans-serif;letter-spacing:2px;margin-top:4px;color:var(--muted)}.header-actions{display:flex;align-items:center;gap:25px;font-size:12px;color:var(--muted)}.quiet{border:1px solid var(--line);border-radius:8px;padding:9px 12px;color:var(--ink);background:#fff}.layout{max-width:1270px;display:grid;grid-template-columns:290px minmax(0,1fr);gap:55px;margin:auto;padding:38px 42px 42px}.sidebar{padding-right:22px;border-right:1px solid var(--line)}.sidebar-head{display:flex;align-items:center;justify-content:space-between}.eyebrow{font-size:10px;letter-spacing:2px;font-weight:650;color:var(--teal);margin:0 0 12px}.sidebar h2{font-size:18px;margin:0 0 25px;font-weight:600;letter-spacing:.6px}.search{display:flex;align-items:center;gap:7px;border:1px solid var(--line);background:#fff;border-radius:8px;padding:10px 12px;color:var(--muted)}.search svg{width:15px;height:15px}.search input{width:100%;min-width:0;border:0;outline:none;font-size:12px;background:none;color:var(--ink)}.filter{display:flex;align-items:center;gap:7px;font-size:12px;margin:19px 0;color:var(--muted)}input[type=checkbox]{accent-color:var(--teal)}.filter span{margin-left:auto;font-size:11px;background:#e9eeea;border-radius:10px;padding:1px 6px}#sentenceList{height:calc(100vh - 345px);min-height:300px;overflow:auto;padding-right:5px;scrollbar-width:thin;scrollbar-color:#cbd7d0 transparent}.chapter-title{font-size:10px;color:var(--muted);letter-spacing:1px;margin:24px 0 10px}.chapter-title:first-child{margin-top:2px}.sentence{display:flex;width:100%;align-items:center;text-align:left;gap:11px;border:1px solid transparent;border-radius:9px;padding:12px 10px;margin-bottom:4px;transition:background .15s}.sentence:hover{background:#eef2ed}.sentence.active{background:#e8efea;border-color:#d5e2d8}.sentence .num{width:23px;font-size:11px;color:#9ca6a3;flex-shrink:0}.sentence.active .num{color:var(--teal);font-weight:650}.sentence .label{font-size:12px;line-height:1.5;display:-webkit-box;-webkit-line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}.sentence .marker{font-size:11px;color:var(--orange);margin-left:auto}.sentence.done .num{color:var(--teal)}.sidebar-note{color:#98a19c;font-size:10px;margin-top:20px}.workspace{min-width:0;max-width:800px}.lesson-heading{display:flex;justify-content:space-between;align-items:center;margin:1px 0 25px}.lesson-heading h1{font:normal 31px/1.25 Georgia,serif;letter-spacing:-.5px;margin:0 0 8px}.lesson-sub{font-size:12px;margin:0;color:var(--muted)}.lesson-tag{font-size:10px;color:var(--teal);border:1px solid #dce5de;border-radius:30px;padding:7px 10px;white-space:nowrap;margin-left:15px}.mode-tabs{display:inline-flex;border:1px solid #e1e6df;background:#eef1eb;border-radius:10px;padding:4px;margin-bottom:20px;gap:3px}.mode-tabs button{font-size:12px;padding:8px 22px;border-radius:7px;color:var(--muted)}.mode-tabs button[aria-pressed=true]{background:#fff;color:var(--ink);box-shadow:0 2px 6px #193f3020}.practice-card{background:#fff;border:1px solid #e0e6df;border-radius:18px;overflow:hidden;box-shadow:0 10px 35px #354c3a05}.card-top{display:flex;align-items:center;justify-content:space-between;margin:0 26px;padding:18px 0 13px;border-bottom:1px solid #edf0eb;font-size:10px;color:var(--muted);letter-spacing:.3px}.weak-button{font-size:11px;color:var(--muted);padding:6px}.weak-button[aria-pressed=true]{color:#b4693e;background:#fff3e9;border-radius:6px}.illustration{padding:24px 26px 13px;min-height:190px;display:flex;align-items:center;justify-content:center;background:linear-gradient(#fff,#fcfdfb)}.illustration button{width:100%;max-width:560px;display:block;padding:0;cursor:zoom-in}.illustration img{width:100%;height:190px;object-fit:contain;display:block}.text-panel{padding:14px 32px 20px;min-height:142px}.text-heading{display:flex;justify-content:space-between;align-items:center;color:var(--muted);font-size:10px;margin-bottom:13px}.text-tools{display:flex;gap:14px;align-items:center}.text-tools button{padding:5px 0;font-size:10px;color:var(--muted)}#fontBtn{font-family:Georgia,serif;font-size:14px}#english{font-size:var(--font-size);font-weight:450;line-height:1.55;letter-spacing:-.3px;margin:0;overflow-wrap:break-word;transition:color .15s}#english.speaking{color:var(--teal)}.reveal{width:100%;padding:30px 8px;background:#f6f8f3;border:1px dashed #cdd9cd;border-radius:9px;color:var(--teal);font-size:13px}.card-footer{display:flex;justify-content:space-between;align-items:center;background:#fbfcf9;border-top:1px solid #edf0e9;padding:13px 26px;font-size:10px;color:var(--muted)}#positionLabel{color:var(--teal);font-variant-numeric:tabular-nums}.practice-settings{display:flex;align-items:center;gap:24px;padding:20px 0}.setting{display:flex;align-items:center;gap:10px;font-size:11px;color:var(--muted)}.segmented{display:flex;border:1px solid #dce4dc;border-radius:6px;overflow:hidden}.segmented button{font-size:10px;padding:7px 10px}.segmented button[aria-pressed=true]{background:#e5eee7;color:var(--teal)}select{border:1px solid #dce4dc;background:transparent;color:var(--ink);padding:7px;border-radius:6px;font-size:10px}.reference-button{margin-left:auto;font-size:10px;color:var(--muted)}.chapter-progress{display:flex;gap:5px}.progress-dot{height:3px;background:#e2e8df;flex:1;border-radius:3px}.progress-dot.completed{background:#a6c7b7}.progress-dot.current{background:var(--teal)}.progress-dot:nth-child(8),.progress-dot:nth-child(15),.progress-dot:nth-child(23){margin-right:7px}#status{font-size:11px;min-height:18px;margin:12px 0 17px;color:var(--muted)}.player{background:#fff;border:1px solid #e0e6df;border-radius:14px;padding:15px 24px 16px}.player-timeline{display:flex;align-items:center;gap:12px;color:var(--muted);font-size:10px;font-variant-numeric:tabular-nums}.player-timeline input{flex:1;min-width:0;accent-color:var(--teal);height:3px;cursor:pointer}.player-controls{display:flex;align-items:center;justify-content:space-between;margin-top:17px}.transport{display:flex;align-items:center;gap:28px}.step{font-size:24px;width:32px;height:38px;line-height:1}.play{height:54px;width:54px;background:var(--navy);border-radius:50%;display:grid;place-items:center;color:#fff;box-shadow:0 4px 12px #153b4b22}.play svg{fill:currentColor;width:23px;height:23px}.side-control{font-size:10px;display:flex;flex-direction:column;gap:4px;align-items:center;min-width:62px;color:#929e9b}.side-control>span{font-size:25px;line-height:1}.side-control[aria-pressed=true]{color:var(--teal)}.mobile-list{display:none}dialog{padding:38px 12px 12px;border:0;border-radius:15px;max-width:min(95vw,1000px);background:#fff}dialog::backdrop{background:#122e3fcc}dialog img{width:100%;display:block;max-height:80vh;object-fit:contain}#closeImage{position:absolute;right:13px;top:8px;font-size:18px}#toast{position:fixed;bottom:25px;left:50%;transform:translateX(-50%);z-index:20;background:#173e4b;color:#fff;border-radius:10px;padding:14px 20px;font-size:12px;max-width:90vw;box-shadow:0 3px 15px #0002}.empty{font-size:12px;line-height:1.8;color:var(--muted);padding:15px 4px}[hidden]{display:none!important}
@media(min-width:1450px){.layout{padding-top:50px;gap:65px}.illustration img{height:225px}.illustration{padding-top:30px;padding-bottom:22px}.text-panel{padding-bottom:28px}.lesson-heading{margin-bottom:32px}}
@media(max-width:1000px){.layout{gap:25px;padding:28px 24px;grid-template-columns:235px minmax(0,1fr)}.lesson-tag{display:none}.lesson-heading h1{font-size:27px}.practice-settings{gap:12px}.reference-button{display:none}.mode-tabs button{padding:8px 15px}.text-panel{padding:14px 22px 22px}}
@media(max-width:700px){:root{--font-size:23px}.topbar{height:74px;padding:0 20px}.brand{font-size:23px;gap:10px}.brand-icon{width:37px;height:37px;border-radius:11px}.brand-sub{font-size:9px}.header-actions{gap:9px}.header-actions>span{display:none}.header-actions .quiet{font-size:10px;padding:8px}.mobile-list{display:inline-block;font-size:11px;padding:7px;color:var(--muted)}.header-actions #listToggle{font-size:0}#listToggle::after{content:'☰';font-size:23px}.layout{display:block;padding:24px 18px 180px}.sidebar{display:none}.sidebar.open{display:block;position:fixed;inset:0;background:var(--paper);z-index:30;padding:26px 24px;border:0;overflow:auto}.sidebar.open #sentenceList{height:calc(100dvh - 220px);max-height:none}.sidebar.open .sidebar-note{margin:15px 0}.sidebar-head h2{margin-bottom:18px}.sidebar.open .sentence{padding:13px 10px}.sidebar.open .sentence .label{font-size:14px}.lesson-heading{margin:0 0 22px}.lesson-heading h1{font-size:28px}.lesson-heading .eyebrow{font-size:9px;margin-bottom:10px}.lesson-sub{font-size:11px}.mode-tabs{display:flex;width:100%;margin-bottom:16px}.mode-tabs button{flex:1;padding:9px 0;font-size:12px}.practice-card{border-radius:15px}.card-top{margin:0 18px;padding:12px 0 9px;font-size:9px}.weak-button{font-size:10px}.illustration{min-height:158px;padding:16px 12px 4px}.illustration img{height:155px;max-height:26vh}.text-panel{padding:14px 20px 22px;min-height:145px}.text-heading{margin-bottom:12px}.card-footer{padding:12px 18px;font-size:9px}#modeHint{max-width:85%;line-height:1.4}.practice-settings{justify-content:space-between;padding:17px 0;gap:8px}.setting{font-size:10px;gap:7px}.segmented button{padding:7px 9px}.chapter-progress{gap:3px}.progress-dot:nth-child(8),.progress-dot:nth-child(15),.progress-dot:nth-child(23){margin-right:4px}#status{font-size:10px;margin:10px 0 15px}.player{position:fixed;bottom:0;left:0;right:0;border-radius:20px 20px 0 0;border:1px solid #e0e6df;padding:15px 25px max(20px,env(safe-area-inset-bottom));z-index:10;box-shadow:0 -5px 25px #203b4908}.player-controls{margin-top:15px}.play{height:55px;width:55px}.transport{gap:24px}.side-control{font-size:10px}.player-timeline{font-size:10px}#toast{bottom:165px;white-space:normal;width:max-content;text-align:center}}
@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;transition:none!important}}