*{box-sizing:border-box}body{margin:0;font:15px system-ui;background:#f5f6f8;color:#17191d}button,input,select,textarea{font:inherit;padding:10px;border:1px solid #ccd1d9;border-radius:10px}button{cursor:pointer;background:#fff}.center{max-width:390px;margin:12vh auto}.card{background:#fff;padding:28px;border-radius:18px;box-shadow:0 8px 30px #0001}.card input{width:100%;margin:6px 0}.card button{width:100%;margin-top:8px;background:#17191d;color:#fff}header{height:62px;padding:0 20px;background:#17191d;color:#fff;display:flex;align-items:center;justify-content:space-between}header small{opacity:.65}main{display:grid;grid-template-columns:320px 1fr;height:calc(100vh - 62px)}aside{background:#fff;padding:18px;overflow:auto;border-right:1px solid #ddd;min-width:0}aside input,aside form button{width:100%;margin:5px 0}.sidehead{display:flex;justify-content:space-between;align-items:center}.doc{padding:13px;margin:9px 0;border:1px solid #ddd;border-radius:14px;min-width:0;overflow:hidden}.doc b,.doc small{display:block;max-width:100%;overflow-wrap:anywhere;word-break:break-word;white-space:normal}.doc b{line-height:1.35}.doc small{color:#68707c;margin-top:4px}.docActions{display:flex;gap:7px;margin-top:9px}.docActions button{width:auto;padding:7px 10px}.danger{color:#a11}#study{overflow:auto;padding:28px;max-width:1100px;width:100%}.toolbar{position:sticky;top:0;background:#f5f6f8ee;backdrop-filter:blur(8px);padding:8px 0;z-index:3;display:flex;gap:6px;align-items:center;flex-wrap:wrap}.progress{height:5px;background:#ddd;border-radius:8px;overflow:hidden;margin:10px 0}.progress div{height:100%;background:#333;transition:.2s}#content{background:#fff;padding:24px;border-radius:16px;line-height:1.7}#content img{max-width:100%;height:auto;border-radius:10px}mark.hl{padding:1px 0;border-radius:2px;cursor:pointer}.hl.yellow,.swatch.yellow,.dot.yellow{background:#ffe86b}.hl.green,.swatch.green,.dot.green{background:#a9efb3}.hl.pink,.swatch.pink,.dot.pink{background:#ffb7cf}.hl.blue,.swatch.blue,.dot.blue{background:#a9dcff}#selectionTools{position:fixed;z-index:50;background:#17191d;color:#fff;padding:7px 9px;border-radius:12px;box-shadow:0 6px 25px #0005}.swatch{width:26px;height:26px;padding:0;border:2px solid #fff;margin-left:4px}.dot{display:inline-block;width:12px;height:12px;border-radius:50%;margin-right:7px}.panelItem{display:block;width:100%;text-align:left;margin:6px 0;white-space:normal;overflow-wrap:anywhere}.panelItem small{display:block;color:#68707c;margin-top:4px}.tabs,.timerBtns{display:flex;gap:5px;flex-wrap:wrap}dialog{border:0;border-radius:16px;padding:22px;min-width:min(92vw,480px);max-width:92vw;max-height:88vh;overflow:auto}dialog input,dialog textarea{width:100%;margin:7px 0}.muted{color:#68707c}.mobileMenu,.mobileClose{display:none}#motBtn{position:fixed;right:20px;bottom:22px;width:54px;height:54px;border-radius:50%;background:#17191d;color:#fff;font-size:22px;z-index:20;touch-action:none}#mot{position:fixed;inset:0;background:#111;color:#fff;z-index:19;padding:18px}.motbox{text-align:center;height:90vh}.motbox img{display:block;margin:12px auto;max-width:95%;height:72vh;object-fit:contain}
@media(max-width:760px){header{padding:0 10px}header b{font-size:14px}main{display:block;height:calc(100vh - 62px)}aside{position:fixed;left:-100%;top:62px;bottom:0;width:min(88vw,340px);z-index:30;transition:.2s;box-shadow:8px 0 30px #0002}aside.open{left:0}.mobileMenu,.mobileClose{display:inline-block}.mobileMenu{margin-bottom:8px}#study{padding:12px;height:100%;overflow:auto}.toolbar{flex-wrap:nowrap;overflow-x:auto;white-space:nowrap;padding-bottom:10px}.toolbar label{display:inline-flex;align-items:center}#content{padding:17px}#sectionTitle{font-size:20px}.doc{max-width:100%}}

.audioTimeline{display:grid;grid-template-columns:auto minmax(120px,1fr) auto auto auto;gap:8px;align-items:center;background:#fff;padding:10px 12px;border-radius:12px;margin:8px 0 14px}.audioTimeline input[type=range]{width:100%;padding:0}.audioTimeline button{padding:7px 9px}.audioTimeline span{font-variant-numeric:tabular-nums;white-space:nowrap}.sectionProgress{margin-top:4px}.sectionProgress>span{font-size:12px;color:#68707c}.sectionProgress .progress{margin:4px 0 8px}@media(max-width:760px){.audioTimeline{grid-template-columns:auto 1fr auto}.audioTimeline #audioTime,.audioTimeline #audioEstimate{grid-column:2/4;font-size:12px}.audioTimeline #audioEstimate{justify-self:end;margin-top:-24px}}

/* v3.2 synchronized TTS transcript */
.tts-active{background:rgba(120,170,255,.34);outline:2px solid rgba(70,120,230,.30);border-radius:4px;padding:1px 0;box-decoration-break:clone;-webkit-box-decoration-break:clone;transition:background .12s ease}
mark.hl .tts-active,.tts-active mark.hl{outline:2px solid rgba(70,120,230,.42)}


/* v3.6 Learning Units — visual segmentation only; TTS engine remains v3.3 */
.learningUnit{position:relative;margin:0 0 22px;padding:18px;border:1px solid #e0e3e8;border-radius:14px;background:#fff;box-shadow:0 2px 10px #00000008}
.learningUnit::before{content:"Unit " attr(data-unit) " / " attr(data-unit-total);display:inline-block;margin:0 0 12px;padding:4px 9px;border-radius:999px;background:#eef1f5;color:#586170;font-size:12px;font-weight:700;letter-spacing:.02em}
.unitSlideImage{margin:0 0 16px;text-align:center;padding:8px;background:#f7f8fa;border-radius:12px}
.unitSlideImage img{display:block;margin:auto;max-height:62vh;object-fit:contain}
.unitText>:first-child{margin-top:0}.unitText>:last-child{margin-bottom:0}
#content:has(.learningUnit){padding:16px;background:#f7f8fa}
@media(max-width:760px){.learningUnit{padding:13px;margin-bottom:14px}.unitSlideImage{padding:5px}.unitSlideImage img{max-height:48vh}}