@font-face{font-family:Newsreader;src:url('fonts/Newsreader-Roman.ttf') format('truetype');font-style:normal;font-weight:200 800;font-display:swap}
@font-face{font-family:Newsreader;src:url('fonts/Newsreader-Italic.ttf') format('truetype');font-style:italic;font-weight:200 800;font-display:swap}
@font-face{font-family:'Source Sans 3';src:url('fonts/SourceSans3.ttf') format('truetype');font-style:normal;font-weight:200 900;font-display:swap}
:root{color-scheme:light;--background:#f8fafa;--ink:#20312f;--navy:#0b2247;--muted:#5f7468;--primary:#004642;--primary-ink:#156963;--primary-soft:#e6f1ee;--surface:#fff;--surface-muted:#f2f5f4;--line:rgba(147,170,163,.24);--success:#146c52;--danger:#a44c48;--warning:#98623c;--reading-size:17px;--ease-out:cubic-bezier(.23,1,.32,1)}
*{box-sizing:border-box}
html{height:100%;scroll-padding-top:16px}
body{height:100%;margin:0;background:radial-gradient(ellipse at 2% -15%,rgba(172,210,198,.22),transparent 40%),radial-gradient(ellipse at 100% 15%,rgba(213,225,242,.25),transparent 35%),linear-gradient(180deg,#fafbfb,#f1f5f3);color:var(--ink);font-family:'Source Sans 3',-apple-system,BlinkMacSystemFont,'PingFang SC','Hiragino Sans GB','Microsoft YaHei',sans-serif;font-size:15px;line-height:1.55;text-rendering:optimizeLegibility;-webkit-font-smoothing:antialiased}
button,input,select,textarea{font:inherit;color:inherit}
button,select{touch-action:manipulation}
button{cursor:pointer}
button:disabled{cursor:default;opacity:.42}
button,select,summary,a{-webkit-tap-highlight-color:transparent}
button{border:0}
a{color:inherit;text-decoration:none}
svg{display:block;flex:none}
[hidden]{display:none!important}
::selection{background:#d7eae3;color:#143e36}
:focus-visible{outline:3px solid #4f9d8b;outline-offset:3px}
input:focus-visible,select:focus-visible{outline:2px solid #408d7d;outline-offset:2px}
button:focus-visible{transition:none}
.sr-only{position:absolute!important;width:1px;height:1px;margin:-1px;padding:0;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}
.skip-link{position:fixed;left:24px;top:-60px;z-index:100;padding:10px 20px;background:var(--primary);color:#fff;border-radius:10px}
.skip-link:focus{top:14px}
.app-shell{display:flex;flex-direction:column;width:min(1600px,100%);height:100%;height:100dvh;margin:0 auto;padding:16px 26px 0;gap:0}
.masthead{flex:none;min-height:61px;display:flex;align-items:center;justify-content:space-between;gap:18px;padding:0 24px;margin-bottom:14px;border:1px solid rgba(255,255,255,.94);border-radius:24px;background:rgba(255,255,255,.76);box-shadow:0 12px 30px rgba(21,44,37,.035),inset 0 1px 0 #fff;backdrop-filter:blur(18px)}
.brand-lockup{display:flex;align-items:center;gap:23px;min-width:0}
.brand-wordmark{font-family:Newsreader,'Iowan Old Style',Baskerville,serif;font-size:30px;font-style:italic;font-weight:500;font-optical-sizing:auto;letter-spacing:-1.2px;line-height:1;color:var(--navy);white-space:nowrap;padding-top:4px}
.brand-dot{color:#377d6c}
.brand-caption{font-size:11px;font-weight:550;letter-spacing:1.4px;color:#62736b;white-space:nowrap}
.brand-caption span{margin:0 7px;color:#b3c0bc}
.header-actions{display:flex;align-items:center;gap:22px}
.font-setting{display:flex;align-items:center;gap:7px;color:#5f726c;font-size:13px}
.font-setting>span:first-child{font-family:Newsreader,serif;font-size:20px;font-weight:500;letter-spacing:-1.5px}
.font-setting select{background:transparent;border:0;padding:5px 19px 5px 4px;cursor:pointer;font-size:12px;border-radius:5px}
.quiet-button{display:flex;align-items:center;justify-content:center;gap:7px;background:transparent;padding:7px 0;color:#596e68;font-size:12px}
.help-icon{width:17px;height:17px;display:inline-flex;align-items:center;justify-content:center;border:1px solid #a8bbb3;border-radius:50%;font-size:11px;font-weight:600}
.toolbar{flex:none;display:flex;align-items:center;gap:19px;min-height:68px;padding:11px 22px;border:1px solid var(--line);background:rgba(255,255,255,.57);border-radius:18px}
.toolbar label{display:flex;min-width:0;flex-direction:column;gap:1px}
.field-label{font-size:10px;font-weight:550;letter-spacing:1.3px;color:#5c7467;line-height:1.45}
.toolbar select{width:100%;max-width:100%;font-size:15px;font-weight:550;line-height:1.45;padding:2px 21px 2px 0;border:0;background:transparent;border-radius:4px;cursor:pointer;text-overflow:ellipsis}
.subject-picker{width:158px;flex:none}.book-picker{width:117px;flex:none}.unit-picker{flex:1}.toolbar-divider{width:1px;height:29px;background:var(--line);flex:none}
.intro{flex:none;display:flex;align-items:center;justify-content:space-between;min-height:92px;gap:20px;padding:15px 4px 17px}
.intro-copy{min-width:0}.source-label{margin:0 0 5px;font-size:11px;color:#5b7568;letter-spacing:1px;font-weight:550;line-height:1.4}
h1{font-family:Newsreader,'Iowan Old Style',Baskerville,serif;font-weight:450;letter-spacing:-.6px;font-optical-sizing:auto;font-size:29px;line-height:1.12;margin:0;overflow-wrap:anywhere;color:#233b35;text-wrap:balance}
.unit-navigation{display:flex;gap:7px;flex:none;padding-right:2px}
.arrow-button{display:grid;place-items:center;width:34px;height:34px;background:rgba(255,255,255,.65);border:1px solid var(--line);border-radius:50%;color:#53756a;transition:background-color 160ms ease,transform 140ms var(--ease-out)}
.arrow-button svg{width:18px;height:18px}
.workspace{flex:1;min-height:0;display:grid;grid-template-columns:minmax(0,1.08fr) minmax(0,1fr);gap:15px;outline:none}
.panel{min-height:0;min-width:0;display:flex;flex-direction:column;border:1px solid rgba(178,195,187,.39);border-radius:20px;overflow:hidden;background:var(--surface);box-shadow:0 6px 20px rgba(35,64,51,.025),inset 0 1px 0 rgba(255,255,255,.9)}
.panel-header{min-height:48px;flex:none;display:flex;align-items:center;justify-content:space-between;gap:12px;padding:9px 25px;border-bottom:1px solid #e7eeea;background:linear-gradient(180deg,#fafcfb,#f7faf8)}
.panel-label{font-size:12px;line-height:1.5;font-weight:600;letter-spacing:.5px;color:#506e62;margin:0;white-space:nowrap}
.panel-label::before{content:'';display:inline-block;width:4px;height:4px;background:#7aab97;border-radius:50%;vertical-align:middle;margin-right:9px}
.answered-count{font-size:11px;font-variant-numeric:tabular-nums;color:#597263;white-space:nowrap}
.source-tabs{display:flex;align-items:center;gap:3px;min-width:0;max-width:100%;flex-wrap:wrap;justify-content:flex-end}
.source-tab,.source-tabs>button{background:transparent;border-radius:7px;padding:5px 10px;font-size:11px;color:#577162;line-height:1.5;white-space:nowrap;transition:background-color 150ms ease,color 150ms ease}
.source-tab[aria-selected='true'],.source-tabs>button[aria-selected='true']{background:#e8f0eb;color:#285a46;font-weight:600}
.panel-content{flex:1;min-height:0;overflow:auto;overscroll-behavior:contain;scrollbar-width:thin;scrollbar-color:#d0dfd6 transparent;font-size:var(--reading-size);padding:26px 30px 42px;line-height:1.8;overflow-wrap:break-word}
.panel-content::-webkit-scrollbar{width:5px;height:5px}.panel-content::-webkit-scrollbar-thumb{background:#d2dfd8;border-radius:5px}
.source-content{color:#35473f}
.source-document p{margin:0 0 1em}.source-document h1,.source-document h2,.source-document h3,.source-document h4{font-family:Newsreader,'Iowan Old Style',serif!important;font-weight:500!important;line-height:1.2!important;letter-spacing:-.4px;color:#223a30!important;margin:.3em 0 1em!important}
.source-document h1{font-size:1.85em!important}.source-document h2{font-size:1.55em!important}.source-document h3{font-size:1.3em!important}
.panel-content img{max-width:100%!important;height:auto!important;object-fit:contain}
.panel-content table{border-collapse:collapse;max-width:100%;font-size:.94em;display:block;overflow-x:auto}
.panel-content td,.panel-content th{padding:7px 9px;min-width:0;vertical-align:top}
.panel-content blockquote{margin:1em 0;padding:0 0 0 16px;border-left:2px solid #d7e5dc}
.panel-content pre{white-space:pre-wrap;overflow-wrap:anywhere}
.q-block{padding:0 0 25px;margin:0 0 24px;border-bottom:1px solid #edf1ee;scroll-margin-top:22px;min-width:0}
.q-block:last-child{border-bottom:0;margin-bottom:0;padding-bottom:0}
.q-block p,.q-block li{line-height:1.7}.q-block p{margin:0 0 .85em}.q-block p:last-child{margin-bottom:0}
.q-heading,.q-number{font-size:11px;font-weight:600;letter-spacing:1.4px;line-height:1.5;color:#577562;margin:0 0 13px}
.instruction{color:#465e51;font-size:.96em}.instruction b,.instruction strong{font-weight:600}
.options{position:relative;margin:12px 0;padding:0;list-style:none}
.options:not(:has(.choice-option))>li{display:flex;gap:12px;margin-bottom:6px;font-size:.94em}.options>li>b{flex:0 0 17px;color:#557061}
.choice-option{display:flex;align-items:flex-start;gap:10px;padding:9px 11px;margin:4px -11px;border-radius:10px;cursor:pointer;line-height:1.6;transition:background-color 140ms ease;min-width:0}
.choice-option:has(input:checked){background:#eef5f0;color:#154d36}
.choice-option input{width:16px;height:16px;margin:5px 1px 0;flex:none;accent-color:#2a7157;cursor:pointer}
.choice-option span{min-width:0}.choice-option b,.choice-option strong{font-weight:600}
.answer-control{display:inline-block;min-width:105px;max-width:100%;font-size:var(--reading-size);line-height:1.4;background:#f8faf8;border:1px solid #cbdcd1;border-radius:6px;padding:5px 9px;color:#244c38;vertical-align:baseline;transition:border-color 140ms ease,background-color 140ms ease;box-shadow:0 1px 2px rgba(20,57,36,.02)}
input.answer-control{width:145px;max-width:100%;min-width:85px}
select.answer-control{padding-right:25px;max-width:100%;width:auto;min-width:92px;cursor:pointer}
.answer-control input,.answer-control select{border:0;background:transparent;font:inherit;max-width:100%;width:100%;padding:0;color:inherit}
.answer-control::placeholder{font-size:.8em;color:#5d7565;opacity:1}
.inline-answer{display:inline-flex;gap:5px;align-items:baseline;max-width:100%;margin:2px 3px}
.inline-answer>strong,.inline-answer>span:not(:has(input,select)){font-size:11px;font-weight:600;color:#55705b;font-variant-numeric:tabular-nums}
.answer-field{display:flex;align-items:flex-start;justify-content:space-between;gap:14px;margin:12px 0;padding:0;min-width:0}
.answer-field>label{flex:1;min-width:0}.answer-field>label strong{margin-right:8px;font-weight:600;color:#5b765e}.answer-field select{flex:none}.answer-field input{flex:none}
.answer-feedback{font-size:12px;line-height:1.6;margin:7px 0 0;color:#586f5d}.correct .answer-control,.answer-control.correct{border-color:#a8cbb4;background:#eef7f0}.incorrect .answer-control,.answer-control.incorrect{border-color:#d5b1ab;background:#fff5f2}
.answer-feedback.correct{color:var(--success)}.answer-feedback.incorrect{color:var(--danger)}.answer-feedback.is-empty{color:#886644}
.answer-row{display:flex;gap:12px;align-items:baseline;margin:5px 0;font-size:.9em}.answer-row>b{flex:none;min-width:22px;color:#285f42}.answer-row>span{min-width:0;overflow-wrap:anywhere}
.explanation,.translation{margin:17px 0 0;border:1px solid #e3ebe5;border-radius:11px;background:#fafcf9;overflow:hidden;font-size:.9em;line-height:1.85}
.explanation>summary,.translation>summary{list-style:none;cursor:pointer;display:flex;align-items:center;justify-content:space-between;gap:10px;color:#55735d;padding:11px 14px;font-size:12px;font-weight:550;line-height:1.5;min-height:41px}
.explanation>summary::-webkit-details-marker,.translation>summary::-webkit-details-marker{display:none}
.explanation>summary::after,.translation>summary::after{content:'+';font-family:Newsreader,serif;line-height:1;font-size:20px;font-weight:400;color:#718a70}
.explanation[open]>summary::after,.translation[open]>summary::after{content:'−'}
.explanation[open]>summary,.translation[open]>summary{border-bottom:1px solid #e5ede5}
.explanation>div,.translation>div{padding:15px 15px 17px;color:#52624f}
.analysis{font-size:.94em;line-height:1.9}.analysis p{margin:0 0 .75em}.analysis p:last-child{margin:0}.analysis strong,.analysis b{font-weight:600}
.is-teaching #reveal{background:#e4efea;color:#175940;border-color:#bed7c7}.is-teaching .questions-panel .panel-label{color:#1f6042}
.quiz-status,.chip{display:inline-flex;align-items:center;border-radius:6px;padding:2px 7px;font-size:10px;background:#edf4ef;color:#5b7560;line-height:1.6;vertical-align:middle}
.player{background:#f3f7f3;border:1px solid #e1ebe1;border-radius:15px;padding:18px 18px 15px;margin:0 0 22px;min-width:0}
.player>strong{font-size:13px;font-weight:600;color:#44664e;display:block;margin-bottom:10px}
audio{display:block;width:100%;height:40px;border-radius:30px;color-scheme:light;margin:10px 0 4px;max-width:100%;font-size:14px}
.player-controls{display:flex;align-items:center;gap:10px 15px;flex-wrap:wrap;margin:14px 0 0;font-size:12px;color:#5b755f;line-height:1.5}
.player-controls label{display:flex;align-items:center;gap:5px;white-space:nowrap;cursor:pointer}.player-controls input{accent-color:var(--primary);width:14px;height:14px;margin:0}
.player-controls select{border:1px solid #dce6dc;border-radius:6px;background:#fff;padding:3px 6px;color:#3b6244;font-size:12px;cursor:pointer}
.player-controls button{background:#fff;border:1px solid #dce6dc;border-radius:7px;padding:4px 9px;color:#3b6244;font-size:12px}
.sentence-list{list-style:none;margin:17px 0 0;padding:0}
.sentence-list>li{margin:0;padding:0;border-bottom:1px solid #e3ebe1}.sentence-list>li:last-child{border:0}
.sentence{position:relative;display:block;width:100%;text-align:left;padding:15px 10px;margin:0;border:0;border-radius:10px;background:transparent;color:#304b35;cursor:pointer;line-height:1.75;font-size:var(--reading-size);transition:background-color 140ms ease}
.sentence.active,.sentence-list li.active{background:#e2eee1}.sentence.active::before{content:'';position:absolute;top:19px;bottom:19px;left:0;width:2px;border-radius:2px;background:#5b9970}
.sentence-time{display:block;font-variant-numeric:tabular-nums;font-size:10px;font-weight:550;letter-spacing:.5px;color:#5a7756;margin:0 0 4px}
.sentence-en{display:block}.sentence-cn{display:block;font-size:.81em;line-height:1.75;color:#5c7254;margin:7px 0 0}
.media-note{font-size:12px;color:#5d7558;line-height:1.7;margin:8px 0}.media-note a{text-decoration:underline;text-underline-offset:3px}.warning{color:var(--warning);font-size:12px;margin:7px 0}
.empty-state,.loading{display:grid;place-content:center;min-height:180px;padding:20px;text-align:center;font-size:14px;color:#5d755e;line-height:1.8}
.practice-bar{flex:none;margin-top:12px;padding:0 6px 0;background:transparent}
.progress-row{display:flex;align-items:center;gap:14px;min-height:39px}
.progress-label{font-size:11px;letter-spacing:1px;color:#57745e;flex:none}.question-nav{display:flex;align-items:center;gap:5px;overflow-x:auto;padding:4px 3px;scrollbar-width:none;min-width:0}.question-nav::-webkit-scrollbar{display:none}
.question-nav button{display:grid;place-items:center;flex:0 0 27px;width:27px;height:27px;border:1px solid #d9e4db;background:rgba(255,255,255,.5);border-radius:7px;font-size:11px;font-weight:550;font-variant-numeric:tabular-nums;color:#577359;transition:background-color 140ms ease,border-color 140ms ease}
.question-nav button.answered{background:#dfede3;border-color:#bdd6c4;color:#386847}.question-nav button.correct{background:#dcefe0;border-color:#a5caae;color:#306742}.question-nav button.incorrect{background:#f7e7e0;border-color:#ddc1b6;color:#a15e46}
.question-nav button[aria-current='true']{box-shadow:0 0 0 2px #6a9b79;outline-offset:3px}
.save-status{margin-left:auto;font-size:10px;color:#5b7451;white-space:nowrap;min-width:0;text-align:right}
.practice-actions{display:flex;align-items:center;justify-content:space-between;gap:16px;padding:7px 0 8px}
.result{font-size:12px;color:#5c7552;line-height:1.5;min-width:0}.result strong{font-family:Newsreader,serif;font-size:25px;font-weight:500;line-height:1;color:#315c3b;font-variant-numeric:lining-nums tabular-nums;margin-right:8px}.result.correct{color:var(--success)}
.action-buttons{display:flex;align-items:center;gap:9px;flex:none}
.primary-button,.secondary-button,.text-button{display:inline-flex;align-items:center;justify-content:center;gap:11px;font-size:12px;line-height:1.5;font-weight:550;min-height:38px;border-radius:10px;padding:9px 17px;white-space:nowrap;transition:background-color 160ms ease,border-color 160ms ease,transform 140ms var(--ease-out)}
.primary-button{color:#f7fbf7;background:var(--primary);border:1px solid var(--primary);box-shadow:inset 0 1px 0 rgba(255,255,255,.15),0 4px 8px rgba(0,70,66,.06)}.primary-button svg{width:15px;height:15px;opacity:.7}
.secondary-button{color:#527459;background:rgba(255,255,255,.7);border:1px solid #d3e1d5}
.text-button{color:#5c7550;background:transparent;border:1px solid transparent;padding-left:8px;padding-right:8px;font-weight:400}
button:active:not(:disabled):not(:focus-visible){transform:scale(.97)}
.sentence:active:not(:disabled){transform:none}
.site-footer{flex:none;display:flex;justify-content:space-between;gap:15px;font-size:9px;line-height:1.5;color:#607653;padding:1px 5px 8px;letter-spacing:.25px}
.mobile-tabs{display:none}
.error-message{flex:none;border:1px solid #e6d1c7;background:#fff8f3;color:#936144;border-radius:10px;padding:9px 15px;font-size:12px;margin-bottom:9px;line-height:1.6}
.app-dialog{border:1px solid rgba(209,224,211,.9);border-radius:22px;background:#fbfdfa;color:var(--ink);padding:0;max-width:min(450px,calc(100% - 30px));width:450px;box-shadow:0 30px 100px rgba(28,58,38,.15)}
.app-dialog::backdrop{background:rgba(29,51,36,.22);backdrop-filter:blur(4px)}
.dialog-content{padding:29px 30px 25px}.dialog-kicker{display:block;color:#5e7654;letter-spacing:1.7px;font-size:10px;font-weight:550;margin-bottom:10px}
.app-dialog h2{font-weight:500;font-size:22px;letter-spacing:-.4px;margin:0 0 12px;color:#375739;line-height:1.5}
.app-dialog p{font-size:13px;color:#5f7551;line-height:1.8;margin:0 0 23px}
.dialog-actions{display:flex;justify-content:flex-end;gap:9px;margin-top:23px}
.dialog-title-row{display:flex;align-items:center;justify-content:space-between}.close-button{font-size:25px;font-weight:300;line-height:1;padding:0 2px;color:#5a744f;background:transparent;margin:-12px -3px 0 0;width:26px;height:26px}
.help-topics{margin:22px 0}.help-topics>div{margin-bottom:16px}.help-topics dt{font-size:12px;color:#50724c;font-weight:550;margin-bottom:4px}.help-topics dd{margin:0;font-size:12px;line-height:1.9;color:#5f764f}.app-dialog .help-footnote{font-size:11px;border-top:1px solid #e3ebe0;padding-top:16px;margin:0;color:#5e7550}
.noscript-notice{position:fixed;inset:0;display:grid;place-items:center;background:#f8fafa;color:#486b50;padding:20px;z-index:200}
@media(hover:hover) and (pointer:fine){.arrow-button:hover:not(:disabled){background:#e6f0e9}.quiet-button:hover{color:var(--primary)}.primary-button:hover:not(:disabled){background:#0b5a50}.secondary-button:hover:not(:disabled){background:#edf4ed;border-color:#b8cdb9}.text-button:hover:not(:disabled){color:#52764c}.choice-option:hover{background:#f5f8f3}.source-tab:hover,.source-tabs>button:hover{background:#edf3ed}.question-nav button:hover{background:#edf3e9;border-color:#a6c0a5}.sentence:hover{background:#e9f2e5}.explanation>summary:hover,.translation>summary:hover{background:#f1f6ed}}
@media(min-width:1700px){.app-shell{padding-left:35px;padding-right:35px}.panel-content{padding:30px 40px 45px}.masthead{margin-bottom:16px}.intro{min-height:101px}h1{font-size:33px}}
@media(max-height:800px) and (min-width:901px){.app-shell{padding-top:10px}.masthead{min-height:53px;margin-bottom:10px}.toolbar{min-height:59px;padding-top:7px;padding-bottom:7px}.intro{min-height:77px;padding-top:11px;padding-bottom:12px}h1{font-size:26px}.panel-header{min-height:43px}.panel-content{padding-top:22px}.practice-bar{margin-top:7px}.progress-row{min-height:34px}.practice-actions{padding:4px 0 6px}.site-footer{padding-bottom:5px}}
@media(max-width:1150px){.app-shell{padding-left:16px;padding-right:16px}.masthead{padding-left:20px;padding-right:20px}.brand-caption{font-size:10px;letter-spacing:.7px}.brand-lockup{gap:18px}.header-actions{gap:15px}.panel-header{padding-left:20px;padding-right:20px}.panel-content{padding:23px 22px 35px}.source-tabs{gap:1px}.source-tab,.source-tabs>button{padding:4px 7px}.toolbar{gap:16px}.source-label{font-size:10px}h1{font-size:26px}.workspace{gap:12px}.save-status{max-width:130px;overflow:hidden;text-overflow:ellipsis}.result{font-size:11px}.text-button{font-size:11px}}
@media(max-width:900px){.app-shell{padding:12px 13px 0}.masthead{padding:0 17px;min-height:57px;margin-bottom:11px;border-radius:20px}.brand-wordmark{font-size:28px}.brand-caption{display:none}.header-actions{gap:15px}.toolbar{padding:9px 15px;gap:12px;border-radius:15px;min-height:64px}.subject-picker{width:140px}.book-picker{width:97px}.toolbar select{font-size:13px}.toolbar-divider{height:26px}.intro{min-height:84px;padding:13px 3px 15px}h1{font-size:26px}.panel-header{padding:9px 17px}.panel-content{padding:22px 20px 35px}.workspace{grid-template-columns:minmax(0,1fr) minmax(0,1fr);gap:10px}.panel{border-radius:16px}.panel-label{font-size:11px;letter-spacing:0}.panel-label::before{margin-right:6px}.source-tab,.source-tabs>button{font-size:10px;padding:4px 6px}.question-nav{gap:4px}.progress-row{gap:8px}.question-nav button{width:24px;height:25px;flex-basis:24px;font-size:10px}.save-status{max-width:95px;font-size:9px}.practice-actions{gap:10px}.action-buttons{gap:7px}.primary-button,.secondary-button,.text-button{padding:8px 12px;font-size:11px;min-height:35px;border-radius:9px}.text-button{padding:8px 4px}.result{font-size:10px;max-width:270px}.result strong{font-size:22px}.site-footer{font-size:8px}.player{padding:14px}.player-controls{gap:8px;font-size:11px}}
@media(max-width:700px){body{height:100%;min-height:100%;background:linear-gradient(180deg,#f5f9f6,#f1f5f1);font-size:14px}.app-shell{height:100dvh;min-height:620px;padding:9px 10px 0}.masthead{min-height:54px;padding:0 15px;margin-bottom:10px;border-radius:19px}.brand-wordmark{font-size:27px}.font-setting{gap:4px}.font-setting select{font-size:11px;padding-right:12px}.font-setting>span:first-child{font-size:18px}.header-actions{gap:11px}.quiet-button{font-size:11px;gap:5px}.quiet-button .help-icon{width:16px;height:16px}.toolbar{display:grid;grid-template-columns:minmax(0,1fr) minmax(0,.65fr);gap:7px 15px;min-height:unset;padding:10px 14px;border-radius:14px}.toolbar-divider{display:none}.subject-picker,.book-picker{width:auto}.unit-picker{grid-column:1/-1;padding-top:6px;border-top:1px solid #e4ece3}.field-label{font-size:9px;letter-spacing:1px}.toolbar select{font-size:13px;padding-top:1px;min-height:25px}.intro{min-height:83px;padding:16px 4px 12px;gap:10px}.source-label{font-size:9px;letter-spacing:.6px;margin-bottom:5px;max-width:100%}h1{font-size:25px;line-height:1.15;letter-spacing:-.35px;text-wrap:unset}.unit-navigation{gap:5px}.arrow-button{width:29px;height:29px}.arrow-button svg{width:16px;height:16px}.mobile-tabs{display:grid;grid-template-columns:1fr 1fr;gap:4px;background:#e9f0e6;border:1px solid #dfe9da;border-radius:11px;padding:3px;margin:0 2px 10px;flex:none}.mobile-tabs button{background:transparent;color:#5c7552;min-height:33px;border-radius:8px;font-size:12px;font-weight:500;padding:7px 10px}.mobile-tabs button[aria-pressed='true']{background:#fff;color:#3f6b43;box-shadow:0 2px 5px rgba(51,82,43,.06)}.workspace{display:block;flex:1;min-height:0}.panel{min-height:0;height:100%;border-radius:15px}.panel-header{min-height:44px;padding:9px 17px}.panel-content{padding:23px 22px 38px;overscroll-behavior:auto;min-height:0;font-size:var(--reading-size)}body[data-mobile-panel='source'] #questions-panel{display:none}body[data-mobile-panel='questions'] #source-panel{display:none}.panel-label{font-size:11px}.source-tab,.source-tabs>button{font-size:10px;padding:4px 7px}.answered-count{font-size:10px}.practice-bar{position:sticky;bottom:0;z-index:20;padding:7px 4px max(7px,env(safe-area-inset-bottom));margin:5px -4px 0;background:rgba(245,249,242,.96);backdrop-filter:blur(14px);border-top:1px solid #dce8d6}.progress-row{gap:7px;min-height:29px}.progress-label{font-size:9px}.question-nav{gap:4px}.question-nav button{width:24px;height:24px;flex-basis:24px;font-size:10px;border-radius:6px}.save-status{display:none}.practice-actions{flex-wrap:wrap;gap:6px;padding:5px 0 0}.result{flex-basis:100%;font-size:10px;max-width:100%;min-height:15px;line-height:1.5}.result strong{font-size:20px}.action-buttons{width:100%;justify-content:flex-end;gap:6px}.primary-button,.secondary-button,.text-button{min-height:35px;font-size:11px;border-radius:9px;padding:8px 12px}.action-buttons .text-button{margin-right:auto;padding-left:0;color:#5b754d}.site-footer{padding:8px 4px;font-size:8px;gap:8px;line-height:1.6}.site-footer>span:last-child{text-align:right}.answer-control{min-width:83px;font-size:var(--reading-size)}input.answer-control{width:132px;min-width:70px}.answer-field{gap:8px;flex-wrap:wrap}.answer-field>label{flex-basis:100%}.answer-field>select,.answer-field>input{margin-left:0}.choice-option{margin-left:-8px;margin-right:-8px;padding-left:8px;padding-right:8px}.dialog-content{padding:25px 23px 22px}.app-dialog h2{font-size:20px}.app-dialog p{font-size:12px}.dialog-actions{gap:7px}.player{padding:13px 13px 10px}.player-controls{gap:9px;font-size:11px}.sentence{padding-left:8px;padding-right:7px}.source-document h1{font-size:1.6em!important}.source-document h2{font-size:1.4em!important}}
@media(max-width:360px){.app-shell{padding-left:7px;padding-right:7px}.brand-wordmark{font-size:24px}.masthead{padding:0 11px}.quiet-button>span:last-child{display:none}.header-actions{gap:9px}.panel-content{padding-left:17px;padding-right:17px}.toolbar{padding-left:12px;padding-right:12px}.action-buttons{gap:5px}.primary-button,.secondary-button{padding-left:10px;padding-right:10px}}
@media(prefers-reduced-motion:reduce){*,*::before,*::after{scroll-behavior:auto!important;animation:none!important;transition:none!important}button:active:not(:disabled){transform:none!important}}
@media print{body,.app-shell{height:auto;min-height:unset;background:#fff}.masthead,.toolbar,.unit-navigation,.header-actions,.mobile-tabs,.practice-bar,.site-footer,audio,.source-tabs,.skip-link{display:none!important}.app-shell{display:block;padding:0;width:100%}.intro{padding:0 0 20px;min-height:unset}.workspace{display:block}.panel,.panel-content{display:block!important;height:auto!important;overflow:visible;border:0;box-shadow:none;padding:0}.panel-header{padding:10px 0;background:transparent}.source-panel{margin-bottom:30px}.q-block{break-inside:avoid}.source-content{margin-bottom:20px}.answer-control{border:0;border-bottom:1px solid #aaa;border-radius:0;background:transparent}.choice-option{background:transparent}h1{font-size:25px}.app-dialog{display:none!important}}
/* Practice controls keep their surrounding source text in its original flow. */
fieldset.options{border:0;min-inline-size:0;padding:0;margin:12px 0}
.choice-text{display:flex;gap:10px;align-items:baseline;flex:1;min-width:0}
.option-letter{display:inline-block;flex:0 0 19px;width:19px;font-weight:600;color:#53735a;font-variant-numeric:tabular-nums}
.choice-text>span:last-child{flex:1;min-width:0}
.word-options{padding:12px 14px;margin:15px 0 20px;list-style:none;border:1px solid #e5ece1;border-radius:11px;background:#f8faf5;font-size:.92em;line-height:1.7}
.word-options>li{display:flex;align-items:baseline;gap:11px;margin:4px 0}
.word-options>li>span{min-width:0;flex:1}.word-options p{margin:0!important}
.instruction{margin:0 0 22px;padding:0 0 1px}.instruction p{margin:0 0 .7em}.instruction p:last-child{margin-bottom:0}
.question-content{min-width:0}
.answer-field.answer-control{display:grid;grid-template-columns:22px minmax(0,1fr) auto;align-items:baseline;gap:10px;width:100%;max-width:100%;min-width:0;border:0;border-radius:0;background:transparent;box-shadow:none;padding:0;margin:15px 0;color:inherit;line-height:1.75;font-size:inherit}
.answer-field.answer-control:not(:has(.statement)){grid-template-columns:22px minmax(0,145px);justify-content:start}
.answer-field.answer-control>strong{grid-column:1;font-size:12px;font-weight:600;color:#56764f;line-height:1.8;margin:0;align-self:baseline}
.answer-field.answer-control>.statement{grid-column:2;min-width:0;overflow-wrap:break-word}
.answer-field.answer-control>.statement p{margin:0!important}
.answer-field.answer-control>input,.answer-field.answer-control>select{grid-column:3}
.answer-field.answer-control:not(:has(.statement))>input,.answer-field.answer-control:not(:has(.statement))>select{grid-column:2}
.inline-answer.answer-control{display:inline-flex;vertical-align:baseline;align-items:baseline;gap:5px;min-width:0;max-width:100%;margin:2px 4px;padding:0;border:0;border-radius:0;background:transparent;box-shadow:none;font:inherit;line-height:1.5;color:inherit}
.inline-answer>.blank-number{flex:none;font-size:10px;font-weight:650;color:#56764f;font-variant-numeric:tabular-nums;user-select:none}
.answer-field.answer-control>input,.answer-field.answer-control>select,.inline-answer.answer-control>input,.inline-answer.answer-control>select{width:135px;min-width:70px;max-width:100%;flex:none;display:inline-block;border:1px solid #cadbcd;border-radius:6px;background:#f8faf7;box-shadow:0 1px 2px rgba(20,57,36,.02);padding:5px 8px;color:#244c38;font:inherit;font-size:.94em;line-height:1.4;vertical-align:baseline}
.inline-answer.answer-control>input{width:125px}
.answer-field.answer-control>select,.inline-answer.answer-control>select{width:76px;min-width:65px;padding:5px 7px;cursor:pointer}
.answer-field.answer-control>input::placeholder,.inline-answer.answer-control>input::placeholder{font-size:11px;color:#5c7558;opacity:1}
.answer-field.answer-control>input[aria-invalid='true'],.answer-field.answer-control>select[aria-invalid='true'],.inline-answer.answer-control>input[aria-invalid='true'],.inline-answer.answer-control>select[aria-invalid='true']{border-color:#cba89d;background:#fff6f2}
.answer-field.answer-control>input.correct,.answer-field.answer-control>select.correct,.inline-answer.answer-control>input.correct,.inline-answer.answer-control>select.correct{border-color:#a9c8ad;background:#eff7ec}
.answer-field.answer-control>input.incorrect,.answer-field.answer-control>select.incorrect,.inline-answer.answer-control>input.incorrect,.inline-answer.answer-control>select.incorrect{border-color:#cba89d;background:#fff6f2}
.answer-feedback>p{margin:4px 0!important;line-height:1.7}.answer-feedback>p.correct{color:var(--success)}.answer-feedback>p.incorrect{color:var(--danger)}.answer-feedback>p.is-empty{color:#876640}
.hide-english .sentence-en,.hide-chinese .sentence-cn{display:none}
.translation-note{display:inline-block;margin-left:4px;vertical-align:1px;padding:0 4px;border:1px solid #d9e5d1;border-radius:4px;color:#5f7750;font-size:9px;line-height:1.65;font-weight:400}
.player-intro{font-family:Newsreader,'Iowan Old Style',serif;font-size:23px;font-weight:450;line-height:1.3;letter-spacing:-.25px;margin:0 0 17px;color:#3f5e3b}
.transcript-controls{padding-top:13px;border-top:1px solid #e1e9dc;margin-top:13px;gap:18px}
.audio-error{font-size:11px;color:#98623c;padding-top:5px}.audio-error button,.error-message button{color:#5b7550;background:rgba(255,255,255,.8);padding:3px 7px;font-size:11px;border:1px solid #d6dfca;border-radius:5px}
@media(max-width:1000px){.answer-field.answer-control{column-gap:8px;grid-template-columns:20px minmax(0,1fr) auto}.answer-field.answer-control>input{width:115px}.inline-answer.answer-control>input{width:112px}.answer-field.answer-control>select,.inline-answer.answer-control>select{width:69px;min-width:63px}.word-options{padding:10px 12px}.choice-text{gap:8px}}
@media(max-width:700px){.answer-field.answer-control{grid-template-columns:20px minmax(0,1fr) auto;gap:7px;margin:15px 0}.answer-field.answer-control:has(.statement)>input,.answer-field.answer-control:has(.statement)>select{grid-column:2;justify-self:start}.answer-field.answer-control:not(:has(.statement)){grid-template-columns:20px minmax(0,135px)}.answer-field.answer-control>input{width:135px}.inline-answer.answer-control>input{width:110px;min-width:65px}.inline-answer.answer-control>select{width:65px;min-width:61px}.inline-answer.answer-control{margin-left:2px;margin-right:2px;gap:4px}.answer-field.answer-control>.statement{grid-column:2/4}.choice-text{gap:8px}.word-options{font-size:.92em}.player-intro{font-size:22px}.instruction{margin-bottom:19px}}
@media print{.answer-field.answer-control>input,.answer-field.answer-control>select,.inline-answer.answer-control>input,.inline-answer.answer-control>select{background:#fff;border:0;border-bottom:1px solid #aaa;border-radius:0;box-shadow:none}}
/* Clear source hierarchy without the browser's oversized document heading margins. */
.question-content h1,.question-content h2,.question-content h3{font-family:Newsreader,'Iowan Old Style',Baskerville,serif;font-optical-sizing:auto;letter-spacing:-.35px;line-height:1.25;color:#2c4636;margin:7px 0 13px;font-weight:550}
.question-content h1{font-size:1.45em}.question-content h2{font-size:1.28em}.question-content h3{font-size:1.15em}
.question-content h1 b,.question-content h2 b,.question-content h3 b{font-weight:550}
.player-controls label{min-height:28px;padding:3px 0}
.player-controls input{width:16px;height:16px;flex:none}
.player-controls select{min-height:28px}
.player-controls button{min-height:28px}
.choice-option:has(input:checked.incorrect){background:#fff4ef;color:#794a35}
.choice-option:has(input:checked.correct){background:#edf6ea;color:#285b38}
@media(max-width:700px){.player-controls{gap:4px 15px}.player-controls label{min-height:40px;padding:6px 0}.player-controls input{width:17px;height:17px}.player-controls select{min-height:34px}.player-controls button{min-height:38px;padding-left:11px;padding-right:11px}.transcript-controls{margin-top:10px;padding-top:8px;gap:5px 19px}.question-nav{gap:5px}.question-nav button{width:29px;height:29px;flex-basis:29px;font-size:11px}.progress-row{min-height:34px}.primary-button,.secondary-button,.text-button{min-height:40px;padding-top:10px;padding-bottom:10px}.choice-option{padding-top:11px;padding-bottom:11px;min-height:44px}.answer-field.answer-control>input,.answer-field.answer-control>select,.inline-answer.answer-control>input,.inline-answer.answer-control>select{min-height:38px}.font-setting select,.quiet-button{min-height:35px}.source-tab,.source-tabs>button{min-height:31px}.explanation>summary,.translation>summary{min-height:44px}}