.fish-classroom-active #heroCard{display:none!important}
.concept-classroom{--cream:#f2e7d3;--gold:#dcb879;--muted:#afa89c;background:linear-gradient(140deg,#1d1b18,#111214 65%);color:var(--cream);border:1px solid #dcb87930;border-radius:28px;padding:32px;margin-bottom:24px;overflow:hidden;font-family:inherit;box-shadow:0 20px 80px #0003}
.concept-classroom *{box-sizing:border-box}.concept-classroom [hidden]{display:none!important}.concept-classroom button,.concept-classroom select,.concept-classroom textarea{font:inherit}.concept-classroom button{cursor:pointer;border:1px solid #ffffff25;border-radius:12px;background:#ffffff08;color:var(--cream);padding:12px 18px;min-height:46px}.concept-classroom button:disabled{opacity:.45;cursor:default}.concept-classroom button:focus-visible,.concept-classroom select:focus-visible,.concept-classroom textarea:focus-visible{outline:2px solid var(--gold);outline-offset:3px}
.concept-topline,.concept-playrow,.concept-actions,.concept-timer{display:flex;align-items:center;gap:16px;flex-wrap:wrap}.concept-topline{justify-content:space-between}.concept-topline p,.concept-small{font-size:11px;letter-spacing:.14em;color:var(--gold)}.concept-badge{font-size:11px;border:1px solid #dcb87940;padding:6px 10px;border-radius:30px;color:var(--gold)}.concept-select{display:flex;gap:12px;margin:25px 0 22px}.concept-select label{font-size:11px;color:var(--muted);display:grid;gap:7px;min-width:0}.concept-select label:first-child{flex:1}.concept-select select{width:100%;max-width:100%;background:#121315;color:var(--cream);border:1px solid #ffffff20;border-radius:9px;padding:10px;font-size:13px}.concept-classroom h1{font-size:clamp(25px,4vw,38px);font-weight:650;letter-spacing:-.05em;line-height:1.3;margin:0 0 15px;word-break:keep-all}.concept-lead{font-size:16px;line-height:1.7;color:var(--muted);max-width:650px;word-break:keep-all}
.concept-sound{height:100px;display:flex;align-items:center;justify-content:center;gap:5px;margin:16px 0;border-block:1px solid #dcb87913;background:radial-gradient(ellipse,#dcb8790b,transparent 70%)}.concept-sound i{height:var(--bar);width:4px;background:linear-gradient(#e5c690,#b99859);border-radius:4px;opacity:.45}.is-playing .concept-sound i{animation:concept-wave 1.5s ease-in-out infinite alternate;animation-delay:var(--delay);opacity:.9}@keyframes concept-wave{to{transform:scaleY(.4)}}.concept-classroom .concept-primary{background:var(--gold);color:#1c1914;border-color:var(--gold);font-weight:700}.concept-playrow>span,.concept-actions>span{color:var(--muted);font-size:12px}.concept-classroom audio{width:100%;margin-top:16px;height:40px;color-scheme:dark}.concept-disclosure{font-size:11px!important;color:var(--muted);line-height:1.7!important}.concept-diagram{display:flex;align-items:center;justify-content:space-between;gap:10px;margin:30px 0}.concept-diagram>div{display:grid;gap:10px;background:#ffffff04;border:1px solid #ffffff10;border-radius:14px;padding:18px 12px;flex:1;min-width:0;text-align:center}.concept-diagram b{font-size:11px;color:var(--gold)}.concept-diagram span{font-size:13px;line-height:1.5;word-break:keep-all}.concept-tabs{display:grid;grid-template-columns:repeat(4,1fr);gap:6px;border-bottom:1px solid #ffffff18;padding-bottom:12px}.concept-tabs button{padding:10px 6px;font-size:13px}.concept-tabs [aria-selected=true]{background:#dcb8791c;border-color:#dcb87980;color:#f0d6a7}.concept-classroom article{padding:23px 0}.concept-classroom h2{font-size:21px;line-height:1.4;letter-spacing:-.035em;margin:0 0 14px}.concept-classroom article p,.concept-classroom li{font-size:15px;line-height:1.95;word-break:keep-all;color:#d4d0c8}.concept-classroom article>button{padding:8px 13px;font-size:12px;margin-top:12px}.concept-actions{border-top:1px solid #ffffff15;padding-top:22px}.concept-classroom #conceptPractice{margin-top:26px;padding:24px;border-radius:18px;background:#ffffff04;border:1px solid #dcb87935;scroll-margin-top:24px}.concept-classroom ol,.concept-classroom ul{padding-left:22px}.concept-classroom li{padding-left:3px;margin-bottom:10px}.concept-timer{justify-content:space-between;padding:16px 0}.concept-timer strong{font-size:36px;font-variant-numeric:tabular-nums;color:var(--gold)}.concept-classroom #conceptPractice>p{font-size:13px;line-height:1.7;color:var(--muted)}.concept-classroom textarea{display:block;width:100%;background:#0f1012;color:var(--cream);border:1px solid #ffffff24;border-radius:10px;padding:12px;margin:10px 0;resize:vertical}.concept-classroom label{font-size:13px}.concept-classroom #conceptStatus,.concept-classroom #conceptSaved{font-size:13px;line-height:1.6;color:var(--gold)}
@media(max-width:520px){.concept-classroom{border-radius:20px;padding:22px 18px}.concept-topline{gap:8px}.concept-topline p{font-size:9px}.concept-select{gap:7px}.concept-select select{font-size:11px;padding:9px 6px}.concept-diagram{gap:5px}.concept-diagram>div{padding:14px 7px}.concept-diagram span{font-size:11px}.concept-tabs button{font-size:11px}.concept-classroom #conceptPractice{padding:17px}.concept-sound{gap:4px}.concept-sound i{width:3px}.concept-classroom h1{font-size:27px}}
@media(prefers-reduced-motion:reduce){.is-playing .concept-sound i{animation:none}}

.fish-classroom-active .topbar{display:grid;grid-template-columns:1fr auto;gap:8px;padding:12px 16px}.fish-classroom-active .topbar .brand{grid-column:1 / -1;min-width:0}.fish-classroom-active .topbar .brand__sub{white-space:nowrap!important;word-break:normal}.fish-classroom-active .topbar__actions{grid-column:1;grid-row:2}.fish-classroom-active .topbar__actions [aria-label="1:1 과외권"]{display:none}.fish-classroom-active .topbar .service-plans-entry{grid-column:2;grid-row:2;margin:0;padding:8px 10px;white-space:nowrap;font-size:11px}.fish-classroom-active #serviceArchive,.fish-classroom-active #lessonReferences,.fish-classroom-active [data-open-archive],.fish-classroom-active #courseSourceDemo,.fish-classroom-active #courseReferences{display:none!important}

.fish-classroom-active .source-demo-card,.fish-classroom-active .source-demo-dialog,.fish-classroom-active #sourceDemoAgain,.fish-classroom-active #profileArchive{display:none!important}

.concept-media-toggle{display:flex;flex-wrap:wrap;gap:8px;margin:16px 0}.concept-media-toggle [aria-pressed=true]{background:#dcb8791c;border-color:#dcb87980;color:#f0d6a7}.concept-video-view{margin:16px 0;border:1px solid #dcb87930;border-radius:14px;overflow:hidden;background:#000}.concept-video-view video{display:block;width:100%;max-height:70vh;aspect-ratio:16/9;object-fit:contain;color-scheme:dark}.concept-video-view video:focus-visible{outline:2px solid var(--gold);outline-offset:-3px}.concept-select #conceptTier{min-height:44px;font-size:14px}

.concept-course-offer{margin:20px 0 28px}.concept-course-offer h2{font-size:clamp(24px,3vw,30px);margin-bottom:10px}.concept-course-offer>p{color:var(--gold);font-size:13px;line-height:1.7}.concept-classroom .concept-value-list{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px;list-style:none;padding:0;margin:18px 0 0}.concept-classroom .concept-value-list li{margin:0;padding:12px;border:1px solid #dcb87925;border-radius:12px;font-size:12px;line-height:1.7}.concept-value-list strong,.concept-value-list span{display:block}.concept-value-list strong{color:var(--cream);margin-bottom:5px;font-size:13px}.concept-value-list span{color:var(--muted)}@media(max-width:600px){.concept-classroom .concept-value-list{grid-template-columns:1fr;gap:8px}.concept-value-list strong{margin-bottom:2px}}

/* Put the lecture first while its video is visible; keep the companion for audio. */
.concept-classroom.has-lecture-video #teacherStage{display:none}.concept-video-view video::cue{font-size:16px;background:rgba(0,0,0,.82);color:#fff}
.guided-lesson-production #conceptPractice{scroll-margin-top:148px}