:root{--bg:#f6f5f0;--paper:#fffefb;--ink:#283e34;--muted:#81897c;--line:#e1e5d9;--green:#305b46;--soft:#e7ecdf;--sidebar:#eeefe7;--en-size:20px;--zh-size:13px;color:var(--ink);background:var(--bg);font:14px/1.6 "Segoe UI","Microsoft YaHei",system-ui,sans-serif;font-synthesis:none}
*{box-sizing:border-box}body{margin:0}button,input,select,textarea{font:inherit}button{color:inherit;cursor:pointer}button:disabled{opacity:.35;cursor:default}button,input,select,textarea{-webkit-tap-highlight-color:transparent}button:focus-visible,input:focus-visible,select:focus-visible,textarea:focus-visible,a:focus-visible{outline:2px solid #779767;outline-offset:4px}[hidden]{display:none!important}button{touch-action:manipulation}a{color:var(--green)}.sr-only{position:absolute;width:1px;height:1px;overflow:hidden;clip:rect(0,0,0,0)}.skip-link{position:fixed;top:-60px;left:280px;background:var(--green);color:white;padding:10px;z-index:100}.skip-link:focus{top:6px}
.sidebar{width:260px;position:fixed;inset:0 auto 0 0;height:100dvh;display:flex;flex-direction:column;background:var(--sidebar);border-right:1px solid #dfe3d6;z-index:40}.brand{display:flex;align-items:center;gap:12px;padding:34px 24px 36px}.book-mark{display:grid;place-items:center;width:36px;height:46px;border:1px solid #76916b;border-radius:3px 8px 8px 3px;font:29px Georgia,serif;color:var(--green);box-shadow:inset 3px 0 #ccd7c1}.brand strong{font-size:12px;display:block;font-weight:600}.brand div>span{display:block;color:var(--muted);font-size:11px;margin-top:2px}.nav-caption{padding:0 24px 13px;font-size:10px;letter-spacing:1.7px;color:#6b8064}.nav-caption span{margin-left:9px;letter-spacing:0;color:#909887}#lesson-nav{padding:0 12px}.lesson-link{width:100%;border:0;border-radius:7px;background:transparent;display:flex;gap:12px;align-items:center;padding:15px 12px;text-align:left;margin-bottom:5px;position:relative}.lesson-link:hover{background:#e5e9dd}.lesson-link[aria-current=true]{background:#dce5d3}.lesson-num{font:17px Georgia,serif;color:#85957a}.lesson-link[aria-current=true] .lesson-num{color:var(--green)}.lesson-link strong{font-size:12px;display:block;font-weight:500}.lesson-link small{display:block;font-size:11px;color:#87907d;margin-top:3px}.lesson-progress{position:absolute;left:42px;bottom:1px;max-width:calc(100% - 55px);height:2px;background:#93ac80;border-radius:2px}.cards-nav{margin:28px 24px 0;border:0;border-top:1px solid #dce2d2;padding:22px 0;display:flex;align-items:center;gap:12px;background:transparent;text-align:left;font-size:12px}.cards-nav>span:first-child{font-size:24px}.cards-nav>span:last-child{margin-left:auto}.cards-nav small{display:block;font-size:10px;color:#8a9381;margin-top:2px}.sidebar-bottom{margin-top:auto;padding:24px;border-top:1px solid #dce2d2}.edition-tag{font-size:10px;letter-spacing:1.6px;color:#62775b}.sidebar-bottom p{font-size:11px;color:#919986;line-height:1.9;margin:8px 0 0}
.main{margin-left:260px;min-height:100vh}.topbar{height:68px;border-bottom:1px solid var(--line);padding:0 44px;display:flex;align-items:center;justify-content:space-between;color:#81907b;font-size:11px}.topbar>div{display:flex;gap:14px;align-items:center}.slash{color:#b4bda8}.local-label{font-size:10px;display:flex;gap:7px;align-items:center}.local-label i{width:5px;height:5px;border-radius:50%;background:#84a273}.workspace{max-width:1100px;margin:auto;padding:42px 52px 24px}.eyebrow{display:flex;align-items:center;gap:12px;font-size:10px;letter-spacing:1.8px;color:#718566}.eyebrow-line{height:1px;width:25px;background:#a6b49b}h1{font:400 44px/1.22 Georgia,"Times New Roman",serif;letter-spacing:-1.1px;margin:15px 0 11px;text-wrap:balance}.subtitle-row{display:flex;align-items:center;justify-content:space-between;gap:12px}.subtitle-row p{margin:0;color:#86917e;letter-spacing:2px;font-size:14px}#lesson-stats{font-size:10px;color:#959c8b;white-space:nowrap}.tabs{display:flex;gap:26px;border-bottom:1px solid var(--line);margin:30px 0 24px}.tabs button{padding:0 0 12px;background:none;border:0;border-bottom:2px solid transparent;color:#8a9380;font-size:12px;white-space:nowrap}.tabs button[aria-selected=true]{color:var(--green);border-color:var(--green);font-weight:600}
.player{background:var(--paper);border:1px solid var(--line);border-radius:11px;padding:18px 22px 0;box-shadow:0 3px 12px #30482004}.player-heading{display:flex;align-items:center;justify-content:space-between}.recording-label{display:flex;gap:8px;align-items:center;font-size:10px;letter-spacing:.6px;color:#7d8b72}.recording-label>span:first-child{font-size:18px;color:#719168}.voice-picker{display:flex;background:#f1f3ea;border-radius:6px;padding:3px;gap:2px}.voice-picker button{border:0;border-radius:4px;background:transparent;padding:4px 10px;font-size:11px;color:#8d9683}.voice-picker button[aria-pressed=true]{background:var(--paper);color:var(--green);box-shadow:0 1px 4px #23431c0e}.voice-picker small{font-size:9px;margin-left:4px;letter-spacing:.4px}.playback-row{display:flex;gap:9px;align-items:center;margin:19px 0 16px}.icon{display:inline-grid;place-items:center;border:0;background:transparent;border-radius:5px;width:32px;height:32px;padding:0;color:#6f8265;flex-shrink:0}.icon:hover{background:var(--soft)}.skip{font-size:11px;width:25px;letter-spacing:-1.2px}.five{font-size:27px;position:relative;line-height:1}.five small{font:8px/1 sans-serif;position:absolute;top:14px;left:14px}.play-button{width:52px;height:52px;display:grid;place-items:center;border:0;border-radius:50%;background:var(--green);color:#fffef8;flex-shrink:0}.play-button:hover{background:#224c38}.play-button svg{width:23px;height:23px;fill:currentColor;stroke:none}#pause-icon{fill:none;stroke:currentColor;stroke-width:4}.timeline{flex:1;min-width:40px;margin-left:12px;padding-top:12px}.time-row{display:flex;justify-content:space-between;margin-top:4px;font-size:10px;color:#929c86;font-variant-numeric:tabular-nums}input[type=range]{appearance:none;height:4px;border-radius:3px;background:linear-gradient(to right,var(--green) var(--fill,0%),#e2e7d9 var(--fill,0%));display:block;width:100%;cursor:pointer;margin:0}input[type=range]::-webkit-slider-thumb{appearance:none;width:10px;height:10px;background:var(--green);border:2px solid var(--paper);border-radius:50%;box-shadow:0 0 0 1px var(--green)}input[type=range]::-moz-range-thumb{background:var(--green);border:0;width:9px;height:9px;border-radius:50%}.player-options{display:flex;align-items:center;gap:19px;padding-bottom:15px;flex-wrap:wrap}.mode-picker{display:flex;background:#eff2e8;border:1px solid #e0e6d5;border-radius:6px;padding:2px}.mode-picker button{border:0;border-radius:4px;background:transparent;padding:5px 12px;font-size:11px;color:#8a947d}.mode-picker button[aria-pressed=true]{background:var(--paper);color:var(--green);box-shadow:0 1px 3px #354d2112}.player-options label,.shadow-options label{display:flex;align-items:center;gap:6px;font-size:11px;color:#7f8b73}select{border:1px solid var(--line);border-radius:5px;background:var(--paper);color:var(--ink);padding:4px 6px;font-size:11px;max-width:100%}input[type=checkbox],input[type=radio]{accent-color:var(--green)}.check-label input{margin:0}.volume-label{margin-left:auto}.volume-label input{width:65px}.player-status{display:flex;align-items:center;justify-content:space-between;gap:15px;border-top:1px solid #e9ecdf;padding:10px 0;font-size:10px;color:#8b957e}.shadow-options{border-top:1px solid var(--line);padding:12px 0;display:flex;gap:20px;align-items:center;flex-wrap:wrap}.shadow-options>span{margin-left:auto;font-size:10px;color:#95a089}.question-box{margin:18px 0 21px;padding:13px 17px;border-left:2px solid #bdcdb0;background:#edf0e6;font-size:12px}.question-box summary{cursor:pointer;display:flex;gap:16px;align-items:baseline;list-style:none}.question-box summary>span:first-child{white-space:nowrap;font-size:10px;color:#8d997e}.question-box summary>span:last-child{font:15px/1.6 Georgia,serif}.question-box p{margin:12px 0 0;color:#7b8a6e;font-size:12px}.question-box #answer-en{font-family:Georgia,serif;font-size:16px}.question-box #answer-zh{margin-top:4px}.text-button{border:0;background:transparent;color:#627d58;padding:8px 0;font-size:11px;display:inline-flex;align-items:center;gap:8px}.text-button:hover{color:#244e36;text-decoration:underline}
.reading-section{background:var(--paper);border:1px solid var(--line);border-radius:10px;overflow:hidden}.reader-toolbar{padding:17px 22px 0;display:flex;align-items:center;justify-content:space-between;gap:12px}.reader-toolbar>div:first-child{display:flex;gap:10px;align-items:center}.reader-toolbar strong{font-size:12px;font-weight:500}.reader-toolbar #row-count{font-size:10px;color:#9ba38e}.reading-options{display:flex;align-items:center;gap:16px;font-size:10px;color:#8b957e}.reading-options label{display:flex;align-items:center;gap:4px;white-space:nowrap}.reading-options input{margin:0}.font-button{border:0;background:none;font:16px Georgia,serif;color:#7c8c70;padding:3px}.reading-hint{font-size:10px;color:#a1a992;margin:9px 22px 17px}.reader{padding:0 12px 8px}.reading-row{display:flex;position:relative;border-left:2px solid transparent;border-radius:5px;margin:3px 0;padding:11px 12px 11px 7px;cursor:pointer;transition:background .15s}.reading-row.paragraph-start:not(:first-child){margin-top:17px}.reading-row:hover{background:#f5f6ef}.reading-row.selected{border-left-color:#a9bf95;background:#f0f4e9}.reading-row.playing{border-left-color:var(--green);background:#eaf0e1}.row-number{width:29px;flex-shrink:0;padding-top:7px;color:#b0b6a5;font:10px Georgia,serif}.row-text{flex:1;min-width:0}.sentence-en{font:var(--en-size)/1.85 Georgia,"Times New Roman",serif;letter-spacing:.05px;margin:0}.sentence-zh{font:var(--zh-size)/1.85 "Microsoft YaHei",sans-serif;color:#919a85;margin:6px 0 0}.hide-translation .sentence-zh{display:none}.word{font:inherit;letter-spacing:inherit;color:inherit;display:inline;border:0;border-radius:3px;background:none;padding:2px 0;margin:0;line-height:inherit}.word:hover,.word:focus-visible{background:#dce8cb;color:#20472b}.word.active-word{background:#c9dbb5;color:#264c31}.reader-footer{border-top:1px solid var(--line);padding:15px 22px;display:flex;align-items:center;justify-content:space-between;font-size:10px;color:#a0a78f}.workspace-foot{display:flex;justify-content:space-between;gap:12px;padding:22px 0 0;font-size:10px;color:#9ba38d}
.section-intro{display:flex;align-items:center;justify-content:space-between;gap:12px;margin:29px 0 21px}h2{font-size:19px;font-weight:500;margin:0}h3{font-size:14px;font-weight:500;margin:0 0 12px}.section-intro p{font-size:11px;color:#949c88;margin:6px 0 0}.button{border:1px solid #dce3d1;background:var(--paper);color:#62795b;font-size:11px;padding:8px 13px;border-radius:6px}.button:hover{background:#edf2e5}.button.primary{background:var(--green);border-color:var(--green);color:#fffef8}.vocabulary-list{border:1px solid var(--line);background:var(--paper);border-radius:10px;overflow:hidden}.vocab-item{padding:20px 24px;border-bottom:1px solid var(--line)}.vocab-item:last-child{border:0}.vocab-main{display:flex;gap:18px;align-items:center}.vocab-index{color:#abb49d;font:12px Georgia,serif;min-width:19px}.vocab-word{border:0;background:none;text-align:left;font:23px/1.3 Georgia,serif;color:#2d513a;padding:0}.vocab-word:hover{color:#75945f}.vocab-main .ipa{margin:3px 0 0}.ipa{font:13px/1.6 "Segoe UI",sans-serif;color:#8d987f}.vocab-meaning{margin-left:auto;display:flex;align-items:center;gap:8px;font-size:12px;color:#77856a}.vocab-meaning small{font:italic 12px Georgia,serif;color:#a1aa93}.vocab-examples{margin:13px 0 0 37px}.vocab-examples summary{font-size:10px;color:#91a180;cursor:pointer}.example-button{display:block;text-align:left;border:0;border-left:2px solid #d6e2c8;background:#f5f7f0;padding:11px 14px;width:100%;margin-top:10px}.example-button>span{display:block;font:16px/1.8 Georgia,serif}.example-button small{display:block;color:#94a087;font-size:11px;margin-top:4px}.notes-list{display:grid;gap:16px}.note-card,.practice-card{background:var(--paper);border:1px solid var(--line);padding:25px;border-radius:9px}.note-card h3{font:23px/1.4 Georgia,serif;margin-bottom:7px}.note-card .note-meaning{font-size:13px;color:#657f58;margin:0}.note-card p{font-size:12px;color:#88967b;line-height:1.9}.note-card button{margin-top:5px}.practice-card{margin:0 0 18px}.practice-heading{display:flex;justify-content:space-between;gap:12px;align-items:center;margin-bottom:15px}.practice-heading h3{margin:0}.practice-heading>span{font-size:10px;color:#9ca68e}.practice-tools{display:flex;justify-content:space-between;align-items:center;font-size:11px;color:#849577}.practice-tools select{margin-left:6px}.practice-en{font:23px/1.9 Georgia,serif;padding:17px 0 0;margin:0;min-height:78px}.practice-zh{font-size:13px;color:#96a086;margin:10px 0 22px}.practice-controls{display:flex;gap:10px;justify-content:space-between;margin-top:15px;flex-wrap:wrap}.practice-en .masked-word{display:inline-block;border-bottom:1px solid #b4c3a3;color:transparent;user-select:none;min-width:28px;line-height:1.2}.practice-en .masked-word::selection{background:none}textarea{display:block;resize:vertical;width:100%;border:1px solid var(--line);border-radius:6px;padding:13px;background:#fcfdf8;color:var(--ink);font:17px/1.85 Georgia,"Microsoft YaHei",serif}#dictation-label{display:block;color:#94a086;font-size:11px;margin:14px 0 6px}.dictation-result{font-size:12px;color:#6e8c60;margin-top:10px}.quiz-item{border:0;border-bottom:1px solid var(--line);margin:0 0 20px;padding:0 0 18px}.quiz-item legend{font:17px/1.7 Georgia,serif;margin-bottom:12px}.quiz-item label{display:flex;align-items:baseline;gap:8px;padding:7px 10px;border-radius:4px;font:14px/1.7 Georgia,serif}.quiz-item label.chosen-correct{background:#eaf1e1}.quiz-item label.chosen-wrong{background:#f6e9dd}.quiz-explanation{font-size:11px;color:#8b9b7c}.writing-prompt{color:#8d9a7f;font-size:12px;line-height:1.9}.writing-footer{display:flex;justify-content:space-between;color:#a0a98f;font-size:10px;margin-top:8px}.word-popover{position:fixed;width:270px;max-width:calc(100vw - 24px);padding:17px;background:#fffef9;border:1px solid #d8e3ca;border-radius:9px;box-shadow:0 8px 35px #2e462222;z-index:80}.word-popover>div{display:flex;gap:8px;align-items:center}.word-popover strong{font:23px Georgia,serif;overflow-wrap:anywhere}.word-popover #popover-play{margin-left:auto}.word-popover p{margin:9px 0;color:#7d8e6f;font-size:13px}.word-popover small{color:#a0ab91;font-size:10px}.cards-settings{border:1px solid var(--line);background:var(--paper);border-radius:9px;padding:20px;display:flex;gap:18px;align-items:center;flex-wrap:wrap;font-size:11px}.cards-settings fieldset{display:flex;gap:14px;border:0;margin:0;padding:0}.cards-settings legend{float:left;padding:0;margin-right:18px;color:#8d9c7d}.cards-settings label{white-space:nowrap}#cards-count{color:#91a180}.card-progress{display:flex;justify-content:space-between;color:#93a081;font-size:11px;margin:26px 0 10px}.word-card{background:var(--paper);border:1px solid var(--line);border-radius:12px;text-align:center;padding:49px 34px;min-height:300px}.card-word{border:0;background:none;color:var(--green);font:42px/1.35 Georgia,serif;padding:0}.card-actions{display:flex;justify-content:center;gap:12px;margin-top:28px}#card-meaning{font-size:15px;color:#8c9c7d;margin:20px 0 0}#card-examples{text-align:left;margin-top:25px}.card-navigation{display:flex;justify-content:space-between;margin-top:18px}.mobile-only{display:none}
@media(min-width:1500px){.workspace{max-width:1160px;padding-top:49px}.sentence-en{line-height:1.95}.reading-row{padding-top:13px;padding-bottom:13px}}
@media(max-width:1100px){.sidebar{width:230px}.main{margin-left:230px}.brand{padding-left:19px;padding-right:14px;gap:9px}.brand strong{font-size:11px}.workspace{padding:32px}.topbar{padding:0 32px}.volume-label{display:none}.player-options{gap:14px}.tabs{gap:22px}h1{font-size:39px}}
@media(max-width:760px){.sidebar{transform:translateX(-100%);transition:transform .2s;width:270px}.nav-open .sidebar{transform:translateX(0)}.nav-backdrop{position:fixed;inset:0;background:#263d3040;border:0;z-index:39}.mobile-only{display:inline-grid}.brand .icon{margin-left:auto}.main{margin-left:0}.topbar{height:58px;padding:0 20px}.topbar>div{gap:10px}.topbar .local-label{display:none}.workspace{padding:28px 20px 20px}.eyebrow{font-size:9px;gap:10px}h1{font-size:35px;letter-spacing:-.7px;margin-top:13px}.subtitle-row p{font-size:13px}.subtitle-row #lesson-stats{font-size:9px}.tabs{margin-top:24px;margin-bottom:21px;gap:0;justify-content:space-between}.tabs button{font-size:11px;padding-bottom:11px}.player{padding:15px 15px 0}.playback-row{gap:6px}.play-button{width:46px;height:46px}.five{width:27px}.skip{width:22px}.timeline{margin-left:7px}.player-options{gap:12px}.mode-picker button{padding:5px 10px}.player-options label{font-size:10px}.player-options select{font-size:10px}.shadow-options{gap:11px}.shadow-options>span{display:none}.question-box{padding:12px 13px}.question-box summary{gap:11px}.question-box summary>span:last-child{font-size:14px}.reader-toolbar{padding:15px 15px 0}.reading-options{gap:10px;font-size:9px}.reading-hint{margin:9px 15px 13px;font-size:9px}.reader{padding:0 7px 7px}.reading-row{padding:10px 8px 10px 2px}.row-number{width:24px;font-size:9px}.sentence-en{font-size:calc(var(--en-size) - 1px);line-height:1.8}.sentence-zh{font-size:12px}.reader-footer{padding:12px 15px}.reader-footer>span{font-size:9px}.workspace-foot{font-size:9px;flex-wrap:wrap;gap:5px}.vocab-item{padding:18px 15px}.vocab-main{gap:9px;flex-wrap:wrap}.vocab-index{min-width:17px}.vocab-word{font-size:23px}.vocab-meaning{margin-left:26px;flex-basis:100%;font-size:12px}.vocab-examples{margin-left:26px}.section-intro h2{font-size:17px}.section-intro p{font-size:10px}.note-card,.practice-card{padding:20px 17px}.note-card h3{font-size:21px}.practice-en{font-size:21px}.practice-controls{gap:7px}.practice-controls .button{font-size:10px;padding:8px 10px}.practice-heading{align-items:baseline}.practice-heading>span{font-size:9px}.practice-heading h3{font-size:13px}.cards-settings{gap:13px}.cards-settings fieldset{gap:9px}.cards-settings legend{margin-right:9px}.word-card{padding:40px 20px}.card-word{font-size:36px}.example-button>span{font-size:15px}}
.reader-toolbar{padding-bottom:15px}.reader-footer{justify-content:flex-end}#sentence-position{margin-left:auto}#save-status{font-size:11px;color:#927d64}
.plain-word{cursor:inherit}.plain-word:not(.active-word):hover{background:transparent;color:inherit}
@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;transition:none!important}}