:root{color-scheme:dark;--navy:#101d31;--navy2:#172b43;--red:#9b352e;--red2:#c0503f;--gold:#c8a767;--gold2:#ecdca7;--ivory:#f5eedc;--ink:#162334;--mist:#c5ced2;--line:#e5d4a62e;--glass:#0d1b2be8;font-family:"PingFang SC","Microsoft YaHei",sans-serif}*{box-sizing:border-box}html,body{width:100%;height:100%;margin:0;overflow:hidden;background:var(--navy);color:var(--ivory)}button,input,select{font:inherit}button{color:inherit;cursor:pointer}button:focus-visible,select:focus-visible,input:focus-visible,#world:focus-visible{outline:2px solid var(--gold2);outline-offset:4px}[hidden]{display:none!important}#world{position:fixed;inset:0;width:100%;height:100%;touch-action:none;cursor:grab;background:radial-gradient(circle at 55% 45%,#33485c,#0d1828);filter:saturate(.92) brightness(.76);transition:filter .9s ease}body.entered #world{filter:saturate(1.02) brightness(.92)}#world:active{cursor:grabbing}.world-grade{position:fixed;inset:0;pointer-events:none;background:linear-gradient(90deg,#0a1424c9 0%,#0c17204d 27%,transparent 55%,#0a14245e 100%),linear-gradient(0deg,#081221d8 0%,transparent 30%,transparent 72%,#0812219e 100%);z-index:1}.world-grade:after{content:"";position:absolute;inset:0;background:radial-gradient(ellipse at center,transparent 38%,#050c176b 100%)}#transition{position:fixed;inset:0;background:#0b1728;z-index:40;opacity:0;pointer-events:none;display:grid;place-items:center;transition:opacity .35s ease}#transition.active{opacity:1;pointer-events:auto}#transition span{width:64px;height:64px;border:1px solid var(--gold);transform:rotate(45deg);opacity:.65;animation:seal 1.2s ease-in-out infinite}@keyframes seal{50%{transform:rotate(135deg) scale(.72);opacity:.25}}
#topbar{position:fixed;top:0;left:0;right:0;height:86px;padding:18px 28px;display:grid;grid-template-columns:1fr auto 1fr;align-items:center;z-index:12;border-bottom:1px solid transparent;transition:.3s}body.entered #topbar{background:linear-gradient(180deg,#0b1625cf,#0b162500);border-color:#e7d9ad1b}.brand{justify-self:start;display:flex;align-items:center;gap:12px;border:0;background:transparent;padding:0;text-align:left}.brand-gem{display:grid;place-items:center;width:39px;height:39px;border:1px solid var(--gold);color:var(--gold);font-size:26px;transform:rotate(45deg)}.brand-gem::first-letter{transform:rotate(-45deg)}.brand b{font-family:"Songti SC","SimSun",serif;font-size:20px;letter-spacing:4px;font-weight:500}.brand small{display:block;margin-top:5px;font-size:9px;letter-spacing:2px;color:#e5e0d0a3}.scene-readout{display:flex;gap:12px;align-items:center;opacity:0;transform:translateY(-5px);transition:.4s}.entered .scene-readout{opacity:1;transform:none}.scene-readout span{font-size:9px;letter-spacing:2px;color:var(--gold)}.scene-readout b{font-family:"Songti SC","SimSun",serif;font-weight:400;font-size:17px;letter-spacing:3px}.top-actions{justify-self:end;display:flex;gap:7px}.top-actions button,#viewControls button,.panel-head button,.dialog-close,#collapseTask{border:1px solid #f0e8d02b;background:#0d1d2e8e;border-radius:3px;padding:9px 13px;font-size:11px;letter-spacing:1px;backdrop-filter:blur(12px);transition:.2s}.top-actions button:hover,#viewControls button:hover{border-color:#c8a767aa;background:#21344ce6}
#welcome{position:fixed;z-index:5;left:7vw;top:25vh;width:min(680px,82vw);transition:.6s}body.entered #welcome{opacity:0;transform:translateY(20px);pointer-events:none}.eyebrow{margin:0;color:var(--gold);font-size:10px;letter-spacing:4px;text-transform:uppercase}h1{font-family:"Songti SC","SimSun",serif;font-size:clamp(50px,6vw,88px);font-weight:400;line-height:1.17;letter-spacing:8px;margin:25px 0 22px;text-shadow:0 8px 28px #0008}h1 em{font-style:normal;color:var(--gold2)}.welcome-copy{font-size:14px;line-height:2;color:#f4efe2c7;letter-spacing:2px}.primary{border:0;background:linear-gradient(135deg,var(--ivory),#ddc991);color:var(--ink);padding:15px 28px;border-radius:3px;letter-spacing:3px;font-weight:650;box-shadow:0 10px 40px #0005}.primary:hover{filter:brightness(1.08);transform:translateY(-1px)}.primary:disabled{opacity:.55;cursor:wait}.boundary{font-size:10px;color:#e7e3d59e;letter-spacing:1.5px;margin-top:18px}
#scene-intro{position:fixed;z-index:5;left:5.2vw;top:18vh;width:min(510px,47vw);padding-left:25px;border-left:1px solid var(--gold);animation:reveal .75s ease both}#scene-intro h2,#briefPanel h2{font-family:"Songti SC","SimSun",serif;font-size:clamp(32px,4.2vw,63px);font-weight:400;letter-spacing:6px;margin:18px 0 15px;text-shadow:0 6px 24px #000a}#scene-intro>p:not(.eyebrow){font-size:13px;line-height:2;color:#f4efe1d2;max-width:450px}#startTaskBtn{border:0;background:transparent;color:var(--gold2);padding:12px 0;letter-spacing:2px;font-size:12px}#startTaskBtn span{margin-left:15px}@keyframes reveal{from{opacity:0;transform:translateX(-18px)}to{opacity:1;transform:none}}
#hotspots{position:fixed;inset:0;z-index:6;pointer-events:none}.hotspot{position:absolute;transform:translate(-50%,-50%);display:flex;align-items:center;gap:10px;border:0;background:transparent;padding:10px;pointer-events:auto;text-shadow:0 2px 8px #000;transition:filter .2s}.hotspot:hover{filter:brightness(1.22)}.hotspot .ring{display:grid;place-items:center;width:48px;height:48px;border:1px solid #f6edd7c4;border-radius:50%;color:var(--gold2);background:#0b1b2994;box-shadow:0 0 0 9px #efe3c50e,0 6px 24px #0007;backdrop-filter:blur(8px);font-family:"Songti SC","SimSun",serif;font-size:16px}.hotspot .ring:after{content:"";position:absolute;width:56px;height:56px;border:1px solid #c8a7674d;border-radius:50%;animation:pulse 2.8s ease-in-out infinite}.hotspot .spot-label{display:flex;flex-direction:column;align-items:flex-start}.hotspot b{font-family:"Songti SC","SimSun",serif;font-weight:400;font-size:18px;letter-spacing:3px}.hotspot small{margin-top:4px;color:#f4ead4ad;font-size:9px;letter-spacing:2px}.hotspot.visited .ring{background:#8e332dcc;border-color:#efdca7}.hotspot.visited small{color:var(--gold2)}@keyframes pulse{50%{transform:scale(1.22);opacity:.15}}
#hotspotNote{position:fixed;z-index:22;top:105px;left:50%;transform:translateX(-50%);width:min(620px,84vw);display:grid;grid-template-columns:auto 1fr auto;gap:15px;align-items:center;background:#0b1929e8;border:1px solid #d8c18748;border-top:2px solid var(--gold);padding:17px 20px;box-shadow:0 16px 50px #0008;backdrop-filter:blur(18px);animation:noteIn .25s ease-out}#hotspotNote>span{display:grid;place-items:center;width:37px;height:37px;border:1px solid var(--gold);border-radius:50%;color:var(--gold)}#hotspotNote b{font-family:"Songti SC","SimSun",serif;font-size:17px;letter-spacing:2px;font-weight:400}#hotspotNote p{margin:5px 0 0;color:#e1dfd5c2;font-size:12px;line-height:1.65}#closeHotspot{border:0;background:transparent;font-size:20px;color:#fff9}@keyframes noteIn{from{opacity:0;transform:translate(-50%,-10px)}to{opacity:1;transform:translate(-50%,0)}}
#taskStage{position:fixed;z-index:9;left:50%;bottom:108px;transform:translateX(-50%);width:min(1040px,82vw);min-height:238px;padding:17px 28px 22px;background:linear-gradient(135deg,#101f31f0,#182a3ce8);border:1px solid #dfca9540;border-radius:4px;box-shadow:0 20px 70px #0009;backdrop-filter:blur(20px);animation:stageUp .42s ease-out}.stage-rule{display:flex;align-items:center;gap:12px;margin-bottom:10px}.stage-rule span{height:1px;flex:1;background:linear-gradient(90deg,transparent,#c8a7675c)}.stage-rule span:last-child{background:linear-gradient(90deg,#c8a7675c,transparent)}.stage-rule i{font-style:normal;font-size:8px;letter-spacing:4px;color:#d7c38a8e}.stage-head{display:flex;align-items:flex-start;justify-content:space-between;gap:20px}.stage-head h2{font-family:"Songti SC","SimSun",serif;font-weight:400;font-size:24px;letter-spacing:3px;margin:6px 0}.stage-head p:not(.eyebrow){font-size:11px;line-height:1.7;color:#d9ddd8a9;margin:0}.activity{margin-top:17px}.task-feedback{min-height:18px;margin-top:13px;font-size:12px;color:var(--gold2);line-height:1.6}.task-feedback.good{color:#d9efc6}.task-feedback.bad{color:#f0aaa2}#reopenTask{position:fixed;z-index:9;bottom:104px;left:50%;transform:translateX(-50%);border:1px solid #d0b67378;background:#12243be6;border-radius:3px;padding:11px 22px;color:var(--gold2);letter-spacing:2px;font-size:11px;backdrop-filter:blur(12px)}@keyframes stageUp{from{opacity:0;transform:translate(-50%,18px)}to{opacity:1;transform:translate(-50%,0)}}
.option-groups{display:grid;grid-template-columns:1fr 1fr auto;align-items:end;gap:22px}.option-group>span,.tempo-side>span,.theme-info>span{display:block;color:var(--gold);font-size:9px;letter-spacing:2px;margin-bottom:8px}.segmented{display:flex;gap:6px}.segmented button,.route-step,.sequence-pool button,.sequence-slot button,.tempo-buttons button,.theme-tabs button,.tap-btn,.review-select,.lyric-step{border:1px solid #e7dcc02c;background:#ffffff08;border-radius:3px;padding:10px 13px;font-size:11px;transition:.18s}.segmented button:hover,.sequence-pool button:hover,.tempo-buttons button:hover,.theme-tabs button:hover{background:#ffffff14}.segmented button.selected,.tempo-buttons button.active,.theme-tabs button.active{background:var(--red);border-color:#dd9c83;color:white}.submit-task{border:0;background:var(--gold2);color:var(--ink);border-radius:3px;padding:11px 20px;font-size:11px;font-weight:650;letter-spacing:2px}.route-track{display:grid;grid-template-columns:repeat(5,1fr);gap:8px}.route-step{position:relative;text-align:left;padding:11px 13px;border-top:2px solid #bda15c5c}.route-step small{display:block;margin-top:6px;color:#d3d7d09e;font-size:8px;letter-spacing:1px}.route-step.lit{background:linear-gradient(135deg,#9b352ecf,#402739ba);border-color:var(--gold2)}.route-step.expected{box-shadow:0 0 0 1px #e2cb8b inset}.sequence-wrap{display:grid;grid-template-columns:1fr auto 1fr;gap:18px;align-items:center}.sequence-pool,.sequence-slots{display:flex;gap:7px;min-height:40px;align-items:center;flex-wrap:wrap}.sequence-slot{min-width:100px;height:39px;border:1px dashed #e2d6b738;border-radius:3px;display:grid;place-items:center;color:#fff5;font-size:10px}.sequence-slot button{width:100%;height:100%;padding:8px}.sequence-arrow{color:var(--gold);font-size:20px}.sequence-actions{display:flex;gap:8px;margin-top:12px}.followup{display:flex;align-items:center;gap:10px;flex-wrap:wrap;margin-top:11px;padding-top:11px;border-top:1px solid var(--line)}.followup span{font-size:11px;color:#e9e5d9}.tempo-layout{display:grid;grid-template-columns:250px 1fr;gap:25px}.tempo-buttons{display:flex;gap:7px}.tempo-note{font-size:9px;color:#d4d8d1a0;margin-top:8px}.theme-layout{display:grid;grid-template-columns:1.4fr .8fr;gap:24px}.theme-tabs{display:grid;grid-template-columns:repeat(5,1fr);gap:6px}.theme-card{margin-top:10px;display:flex;gap:8px}.theme-card span{flex:1;padding:9px;border-left:1px solid var(--gold);background:#ffffff06;font-size:11px}.theme-card small{display:block;color:#d8d9d1a1;font-size:8px;margin-bottom:5px}.tap-zone{display:grid;grid-template-columns:1fr auto;align-items:end;gap:10px}.tap-btn{min-width:150px;font-family:"Songti SC","SimSun",serif;font-size:20px;color:var(--gold2)}.beat-lights{display:flex;gap:5px;margin-top:9px}.beat-lights i{width:18px;height:4px;background:#ffffff1d}.beat-lights i.on{background:var(--gold2);box-shadow:0 0 12px #e0c478}.compare-note{font-size:10px;line-height:1.7;color:#dcded5a8;margin:9px 0 0}.review-layout{display:grid;grid-template-columns:.65fr 1.35fr;gap:25px}.lyric-steps{display:flex;align-items:center;gap:6px}.lyric-step{font-family:"Songti SC","SimSun",serif}.lyric-step.revealed{background:#9b352eaa;border-color:#d9b978}.lyric-arrow{color:#c8a767}.match-grid{display:grid;grid-template-columns:1fr 125px;gap:7px;align-items:center}.match-grid label{font-size:11px}.review-select{color:var(--ivory)}.review-select option{background:var(--navy)}
#sceneNav{position:fixed;z-index:10;bottom:30px;left:50%;transform:translateX(-50%);display:flex;align-items:center;padding:6px;border:1px solid #e4d5af30;background:#0c1929d9;border-radius:4px;backdrop-filter:blur(18px);box-shadow:0 10px 35px #0008}.scene-nav-btn{position:relative;border:0;border-right:1px solid #ffffff13;background:transparent;padding:8px 16px;min-width:102px}.scene-nav-btn:last-child{border-right:0}.scene-nav-btn span{display:block;color:#c7b171;font-size:8px;letter-spacing:2px;margin-bottom:4px}.scene-nav-btn b{font-family:"Songti SC","SimSun",serif;font-size:12px;font-weight:400;letter-spacing:2px}.scene-nav-btn.active{background:linear-gradient(135deg,#96352d,#632b2d)}.scene-nav-btn.visited:after{content:"";position:absolute;top:4px;right:5px;width:4px;height:4px;border-radius:50%;background:var(--gold2)}#viewControls{position:fixed;z-index:8;right:25px;bottom:31px;display:flex;gap:4px}#viewControls button{padding:8px 10px;background:#0c1929d0}footer{position:fixed;z-index:4;bottom:10px;left:25px;right:25px;display:flex;justify-content:space-between;font-size:8px;letter-spacing:1px;color:#f6eddaa2;pointer-events:none}
#briefPanel{position:fixed;z-index:18;left:0;top:86px;bottom:0;width:min(540px,47vw);padding:8vh 5vw;background:linear-gradient(105deg,#0a1625fa,#10233aef);border-right:1px solid #ddc78e3d;box-shadow:30px 0 80px #0007;backdrop-filter:blur(20px);animation:drawerLeft .35s ease-out}.ornament{color:var(--gold);font-size:35px;margin-bottom:25px}#briefPanel h2{font-size:42px}#briefPanel>p:not(.eyebrow,.source){font-size:14px;line-height:2;color:#e9e6ddc2}.source{font-size:9px;line-height:1.7;color:#c6ccc8a0}.source:before{content:"依据 · ";color:var(--gold)}#briefPanel .primary{margin-top:25px;font-size:11px}@keyframes drawerLeft{from{opacity:0;transform:translateX(-20px)}to{opacity:1;transform:none}}
#teacherPanel{position:fixed;z-index:25;top:0;right:0;width:min(410px,90vw);height:100%;padding:30px;background:#0b1929f8;border-left:1px solid #dcc78d45;box-shadow:-30px 0 80px #0008;backdrop-filter:blur(22px);animation:drawerRight .3s ease-out}.panel-head,.dialog-head{display:flex;justify-content:space-between;align-items:flex-start;gap:18px}.panel-head h2,.dialog-head h2{font-family:"Songti SC","SimSun",serif;font-weight:400;letter-spacing:4px;margin:8px 0;font-size:28px}.panel-head button,.dialog-close{font-size:23px;border:0;background:transparent;padding:4px}#teacherPanel>p{font-size:11px;line-height:1.8;color:#ced4d1a8}#teacherScenes{display:grid;gap:8px;margin-top:25px}#teacherScenes button{display:grid;grid-template-columns:48px 1fr auto;align-items:center;text-align:left;border:1px solid #ffffff16;background:#ffffff06;padding:13px 15px;color:var(--ivory)}#teacherScenes button span{color:var(--gold);font-size:9px;letter-spacing:2px}#teacherScenes button b{font-family:"Songti SC","SimSun",serif;font-weight:400;letter-spacing:2px}#teacherScenes button small{color:#ffffff61}#teacherScenes button.active{border-color:#c8a76788;background:#9b352e42}@keyframes drawerRight{from{opacity:0;transform:translateX(20px)}to{opacity:1;transform:none}}
.side-dialog{position:fixed;inset:15px 15px 15px auto;margin:0;width:min(560px,calc(100vw - 30px));height:calc(100dvh - 30px);max-height:none;padding:26px;background:#0b1929f8;color:var(--ivory);border:1px solid #d7c58f47;border-radius:4px;box-shadow:0 25px 90px #000b;overflow:auto}.side-dialog::backdrop{background:#07101eba;backdrop-filter:blur(4px)}.side-dialog[open]{animation:drawerRight .3s ease-out}.page-nav{display:flex;gap:6px;flex-wrap:wrap;margin:20px 0 13px}.page-nav button{border:1px solid #ffffff24;background:#ffffff07;color:#e8e2d3;padding:8px 10px;border-radius:2px;font-size:10px}.page-nav button.active{background:var(--red);border-color:#d7b777}.book-frame{background:#e9e2d0;padding:6px;border-radius:2px}.book-frame img{display:block;width:100%;height:auto}.media-notice{border-left:2px solid var(--gold);background:#ffffff07;padding:13px;font-size:11px;line-height:1.8;color:#eadfbd}.media-slot{margin:26px 0;padding-top:20px;border-top:1px solid var(--line)}.media-slot>span{font-size:10px;letter-spacing:3px;color:var(--gold)}.media-slot p{font-size:12px;color:#d5d9d5a9;overflow-wrap:anywhere}.media-slot audio,.media-slot video{width:100%;max-height:280px}.media-slot label{display:inline-block;margin-top:9px;border:1px solid #ffffff2f;padding:9px 13px;font-size:10px;cursor:pointer}.media-slot input{position:absolute;width:1px;height:1px;opacity:0}
#toast{position:fixed;z-index:50;left:50%;bottom:118px;transform:translate(-50%,12px);opacity:0;pointer-events:none;background:#12243bed;border:1px solid #cfba7f61;border-radius:3px;padding:11px 18px;font-size:11px;box-shadow:0 10px 35px #0007;transition:.22s}#toast.show{opacity:1;transform:translate(-50%,0)}
@media(max-width:900px){#topbar{grid-template-columns:1fr auto;height:76px;padding:14px 18px}.scene-readout{display:none}.top-actions{gap:4px}.top-actions button{padding:8px;font-size:9px}#teacherBtn,#fullscreenBtn{display:none}.brand b{font-size:16px}.brand small{font-size:7px}#scene-intro{top:17vh;left:7vw;width:70vw}#taskStage{width:94vw;bottom:96px;padding:14px 18px;max-height:53vh;overflow:auto}.option-groups{grid-template-columns:1fr}.route-track{grid-template-columns:repeat(3,1fr)}.tempo-layout,.theme-layout,.review-layout{grid-template-columns:1fr}.sequence-wrap{grid-template-columns:1fr}.sequence-arrow{display:none}.theme-tabs{grid-template-columns:repeat(3,1fr)}#sceneNav{max-width:94vw;overflow-x:auto;justify-content:flex-start}.scene-nav-btn{min-width:90px;padding:8px 10px}#viewControls{display:none!important}footer{left:15px;right:15px}.hotspot .spot-label{display:none}#briefPanel{top:76px;width:88vw;padding:7vh 7vw}}
@media(max-width:600px){#bookBtn,#muteBtn{display:none}h1{font-size:44px;letter-spacing:5px}#welcome{top:23vh}.welcome-copy{font-size:12px}.scene-nav-btn{min-width:78px}.scene-nav-btn b{font-size:10px}.scene-nav-btn span{font-size:7px}.route-track{grid-template-columns:1fr 1fr}.segmented{flex-wrap:wrap}.theme-tabs{grid-template-columns:1fr 1fr}.tap-zone{grid-template-columns:1fr}.lyric-steps{flex-wrap:wrap}.match-grid{grid-template-columns:1fr 110px}}
@media(prefers-reduced-motion:reduce){*,*:before,*:after{animation:none!important;transition:none!important;scroll-behavior:auto!important}}

/* 弦子学习舞台的独立前景美术。 */
#taskStage{overflow:visible}
#taskStage.has-art .stage-head,#taskStage.has-art .activity,#taskStage.has-art .task-feedback{padding-right:185px}
#stageArt{position:absolute;right:8px;bottom:0;width:190px;height:290px;margin:0;pointer-events:none;overflow:hidden}
#stageArt:before{content:"";position:absolute;inset:16% 0 0;background:radial-gradient(circle,#d8b86a2b,transparent 68%);filter:blur(8px)}
#stageArt img{position:relative;display:block;width:100%;height:270px;object-fit:contain;object-position:center bottom;filter:drop-shadow(0 15px 28px #0008);opacity:.78;transition:.35s}
#stageArt.focused img{opacity:1;filter:drop-shadow(0 0 18px #e2c67a88) drop-shadow(0 15px 28px #0008);transform:translateY(-3px)}
#stageArt figcaption{position:absolute;right:0;bottom:5px;padding:4px 7px;background:#0b1829c9;color:#e4ddc8a1;font-size:7px;letter-spacing:1px}
@media(max-width:900px){#stageArt{display:none!important}#taskStage.has-art .stage-head,#taskStage.has-art .activity,#taskStage.has-art .task-feedback{padding-right:0}}

/* 1174×768 教室屏代表检查后的必要可读性修正。 */
body.entered #world{filter:saturate(1.02) brightness(1)}
body.entered .world-grade{background:linear-gradient(90deg,#0a142475 0%,#0c17202e 27%,transparent 55%,#0a14243b 100%),linear-gradient(0deg,#0812218a 0%,transparent 27%,transparent 76%,#08122168 100%)}
body.entered .world-grade:after{background:radial-gradient(ellipse at center,transparent 48%,#050c1745 100%)}
.hotspot b{white-space:nowrap}
@media(min-width:901px){.stage-head h2{font-size:28px}.stage-head p:not(.eyebrow){font-size:13px}.segmented button,.route-step,.sequence-pool button,.sequence-slot button,.tempo-buttons button,.theme-tabs button,.review-select,.lyric-step{font-size:14px}.submit-task{font-size:14px}.task-feedback{font-size:14px}.followup span,.match-grid label{font-size:13px}.hotspot{max-width:calc(100vw - 56px)}}

/* V4: the complete 16:9 composition is the default view. The older sphere is opt in. */
@font-face{font-family:"雪域宋体";src:url("assets/fonts/title.woff2") format("woff2");font-display:swap}
:root{--navy:#101c2d;--navy2:#172a40;--red:#9d5946;--red2:#b87655;--gold:#c7a76a;--gold2:#f1dca9;--ivory:#fbf7ed;--line:#d6c49a42;--glass:#102037e8}
body{background:#101c2d}
#heroView{position:fixed;inset:0;width:100%;height:100%;object-fit:contain;background:#101c2d;z-index:0}
#world{display:none;filter:none!important;background:#101c2d}
body.panorama #world{display:block}
body.panorama #heroView{display:none}
.world-grade,.entered .world-grade,body.entered .world-grade{background:linear-gradient(180deg,#091a31a8 0%,transparent 20%,transparent 70%,#091a31b5 100%)}
body:not(.entered) .world-grade{background:linear-gradient(90deg,#081a32c9 0%,#0c213f4d 43%,transparent 75%),linear-gradient(180deg,#091a316e,transparent 45%,#091a319c)}
.world-grade:after,body.entered .world-grade:after{display:none}
#transition{background:#11233b}
#topbar,body.entered #topbar{height:74px;padding:12px 28px;background:linear-gradient(180deg,#101d30db,#101d3000);border:0}
.brand-gem{width:32px;height:32px;font-size:18px;border-color:#e7ce98a6}
.brand b,.scene-readout b,h1,#scene-intro h2,#briefPanel h2,.stage-head h2,.panel-head h2,.dialog-head h2,.hotspot b,.scene-nav-btn b{font-family:"雪域宋体","Songti SC","Noto Serif CJK SC",serif}
.brand b{font-size:21px;letter-spacing:3px;font-weight:400}
.brand small{font-size:9px;letter-spacing:1px;color:#f6f0ddc4}
.scene-readout{gap:8px}.scene-readout b{font-size:15px;letter-spacing:2px}.scene-readout span{font-size:9px}
.top-actions{gap:5px}
.top-actions button,#viewControls button{border-color:#f3e4c650;border-radius:999px;background:#13233bc9;padding:9px 13px;color:#fbf7ed;font-size:11px;letter-spacing:0;box-shadow:0 4px 14px #0c192229}
.top-actions button:hover,#viewControls button:hover{background:#273d57;border-color:#e4c98d}
.top-actions #viewModeBtn{border-color:#dcbf80;color:#f8e8c5}
#welcome{left:7vw;top:27vh;width:min(620px,80vw)}
#welcome h1{font-size:clamp(58px,6vw,90px);letter-spacing:5px;line-height:1.16;text-shadow:0 4px 20px #0913239e}
#welcome h1 em{color:#f5dfac}
.welcome-copy{font-size:15px;line-height:1.7;letter-spacing:2px;color:#fff8e9}
.eyebrow{font-size:10px;letter-spacing:2.5px;color:#f4d695}
.boundary{font-size:10px;color:#f8ecdaa9}
#scene-intro{top:auto;bottom:139px;left:4vw;width:auto;max-width:min(440px,56vw);padding:0;border:0;animation:reveal .45s ease both;pointer-events:none}
#scene-intro .eyebrow{font-size:9px;letter-spacing:2px;max-width:360px;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
#scene-intro h2{font-size:clamp(31px,3.4vw,52px);margin:7px 0 0;letter-spacing:3px;line-height:1.2;color:#fff9ed}
#sceneIntroText,#startTaskBtn{display:none!important}
#hotspots{z-index:7}
.hotspot{flex-direction:column;gap:2px;padding:0;min-width:88px;text-shadow:0 2px 10px #061627bb;transition:transform .22s ease,filter .22s ease;filter:drop-shadow(0 12px 16px #08172276)}
.hotspot:hover{transform:translate(-50%,-56%);filter:drop-shadow(0 16px 23px #0817229e)}
.hotspot .ring{position:relative;width:76px;height:76px;overflow:visible;border:1px solid #f7e8c6db;background:#12243aa1;box-shadow:0 0 0 6px #f2dbab17,0 8px 23px #0b1a2c9c;backdrop-filter:blur(8px)}
.hotspot .ring:after{width:88px;height:88px;border-color:#efd9a776;animation:pulse 3s ease-in-out infinite}
.hotspot .ring img{display:block;width:86px;height:86px;object-fit:contain;filter:drop-shadow(0 3px 7px #0b1b29b4);pointer-events:none}
.hotspot .spot-label{display:block!important;margin-top:3px;padding:3px 9px;border-radius:999px;background:#12243bc4;border:1px solid #ead7ae67;backdrop-filter:blur(8px)}
.hotspot b{font-size:13px;letter-spacing:1px;white-space:nowrap;color:#fff9ea}
.hotspot.visited .ring{background:#254459c2;border-color:#efdaaa}.hotspot.visited .spot-label{border-color:#d5ba81b5}
#sceneNav{bottom:19px;gap:5px;width:min(800px,72vw);justify-content:center;padding:6px;background:#0d1c2ddc;border:1px solid #e6d2a665;border-radius:16px;box-shadow:0 12px 38px #09142180}
.scene-nav-btn{flex:1;min-width:0;padding:3px 3px 5px;border:0;border-radius:10px;background:transparent;overflow:hidden}
.scene-nav-btn img{display:block;width:100%;height:52px;object-fit:cover;border-radius:7px;filter:saturate(.8) brightness(.87)}
.scene-nav-btn b{display:block;overflow:hidden;text-overflow:ellipsis;white-space:nowrap;font-size:11px;letter-spacing:1px;margin-top:4px;color:#f6eee0}
.scene-nav-btn.active{background:#f7eddd}.scene-nav-btn.active img{filter:none}.scene-nav-btn.active b{color:#1b2d42}
.scene-nav-btn.visited:after{width:6px;height:6px;top:7px;right:7px;background:#e9cf92;box-shadow:0 0 0 2px #112032c9}
#viewControls{right:18px;bottom:23px}
body:not(.panorama) #viewControls{display:none!important}
#reopenTask{bottom:111px;left:auto;right:22px;transform:none;border-radius:999px;background:#172b43d9;color:#f2e0b7;padding:11px 17px}
#taskStage{bottom:112px;background:#10223aef;border-radius:15px;border-color:#dec79769;box-shadow:0 22px 70px #05132395;max-height:min(65vh,630px);overflow:auto}
#taskStage.has-art .stage-head,#taskStage.has-art .activity,#taskStage.has-art .task-feedback{padding-right:185px}
.segmented button.selected,.tempo-buttons button.active,.theme-tabs button.active,.lyric-step.revealed{background:#9a674d;border-color:#e6ca93}
.route-step.lit{background:linear-gradient(135deg,#a36f4e,#554540)}
#briefPanel,#teacherPanel,.side-dialog{background:#12243bf8;color:#faf5e9}
.side-dialog{border-radius:16px}
.media-choices{display:flex;gap:7px;flex-wrap:wrap;margin:17px 0 10px}
.media-choices button{border:1px solid #e2d3b171;background:#fbf7ed12;color:#f8f1e4;border-radius:999px;padding:9px 13px;font-size:11px}
.media-choices button.active{background:#f5e8d0;color:#16283d;border-color:#f5e8d0}
.media-item-note{margin:4px 0 12px;color:#eadbc0;font-size:11px;line-height:1.6}
#mediaImageFrame{margin:13px 0;background:#0b1b2b;padding:8px;border-radius:10px}
#mediaImageFrame img{display:block;width:100%;max-height:50vh;object-fit:contain}
#mediaImageTitle{font-size:11px;color:#e9d7b4;margin:9px 4px 3px}
.local-pickers{display:flex;gap:8px;margin-top:20px}.local-pickers label{position:relative;display:block;border:1px solid #e1c88d7a;border-radius:999px;padding:9px 12px;font-size:10px;cursor:pointer;color:#ead9b4}.local-pickers input{position:absolute;width:1px;height:1px;opacity:0}
#guide{--guide-scale:1;position:fixed;z-index:8;right:2vw;bottom:117px;width:clamp(100px,12vw,178px);transform:scale(var(--guide-scale));transform-origin:right bottom}
#guideAvatar{border:0;background:transparent;padding:0;width:100%;position:relative;filter:drop-shadow(0 15px 18px #0715239d);transition:transform .25s}
#guideAvatar:hover{transform:translateY(-5px)}
#guideAvatar img{display:block;width:100%;max-height:34vh;object-fit:contain;object-position:center bottom}
#guideAvatar span{position:absolute;right:0;bottom:0;padding:6px 10px;background:#f6e9d4;color:#1b2e43;border-radius:999px;font-size:10px;white-space:nowrap;box-shadow:0 4px 14px #06172674}
#guidePanel{position:absolute;right:100%;bottom:8px;width:min(280px,65vw);margin-right:8px;padding:17px;background:#11233de9;border:1px solid #e4c9909e;border-radius:13px;box-shadow:0 12px 38px #06152399;backdrop-filter:blur(18px)}
#guidePanel h3{font-family:"雪域宋体","Songti SC",serif;font-size:20px;font-weight:400;margin:10px 0}
#guidePanel p:not(.eyebrow){font-size:12px;line-height:1.7;color:#f8efde;margin:7px 0}
#guidePanel small{color:#e4cca3ad;font-size:9px}
#closeGuide{position:absolute;right:8px;top:7px;border:0;background:transparent;font-size:20px}
.guide-size{display:flex;gap:6px;margin-top:14px}.guide-size button{border:1px solid #e5d0a376;background:#ffffff10;padding:6px 10px;border-radius:7px;font-size:11px}.guide-size button:last-child{margin-left:auto}
footer{bottom:4px;left:13px;right:13px;font-size:8px}
@media(max-width:1100px){.scene-readout{display:none}#topbar{grid-template-columns:1fr auto}.top-actions{max-width:70vw;overflow-x:auto}.top-actions button{white-space:nowrap}#guide{right:10px;bottom:105px}#sceneNav{width:min(740px,72vw)}}
@media(min-width:701px){#bookBtn,#briefBtn,#teacherBtn,#backSceneBtn{display:none!important}}
@media(max-width:900px){#fullscreenBtn{display:block}}
@media(max-width:700px){#topbar{height:62px;padding:8px 10px}.brand-gem,.brand small{display:none}.brand b{font-size:17px;white-space:nowrap}.top-actions{max-width:68vw}.top-actions button{font-size:10px;padding:7px 9px}#bookBtn,#muteBtn,#fullscreenBtn{display:block}#briefBtn,#teacherBtn{display:none}#welcome{left:7vw;top:26vh}#welcome h1{font-size:clamp(43px,12vw,61px)}#scene-intro{left:14px;bottom:132px;max-width:52vw}#scene-intro h2{font-size:28px}#scene-intro .eyebrow{display:none}#sceneNav{width:calc(100vw - 20px);bottom:13px;max-width:none;gap:2px;padding:4px}.scene-nav-btn img{height:42px}.scene-nav-btn b{font-size:9px;letter-spacing:0}#guide{width:90px;bottom:110px;right:6px}#guideAvatar img{max-height:25vh}#guidePanel{width:min(230px,62vw)}.hotspot{min-width:64px}.hotspot .ring{width:58px;height:58px}.hotspot .ring img{width:66px;height:66px}.hotspot .ring:after{width:68px;height:68px}.hotspot b{font-size:10px}#taskStage{width:calc(100vw - 16px);bottom:94px;max-height:65vh;padding:14px}#taskStage.has-art .stage-head,#taskStage.has-art .activity,#taskStage.has-art .task-feedback{padding-right:0}#reopenTask{bottom:96px;right:8px;font-size:10px;padding:8px 10px}footer{display:none}}

/* V5 digital guide: still cover until the teacher starts a transparent video. */
#guideAvatar{display:block;aspect-ratio:2/3}
#guideAvatar img,#guideAvatar video{position:absolute;inset:0;width:100%;height:100%;max-height:none;object-fit:contain;object-position:center bottom}
#guideAvatar video{opacity:0;transition:opacity .2s ease;pointer-events:none}
#guideAvatar video.playing{opacity:1}
#guideAvatar span{z-index:2}
.guide-playback{display:flex;gap:6px;margin-top:13px}
.guide-playback button{flex:1;border:1px solid #e5d0a391;background:#f6e9d41b;border-radius:8px;padding:8px 10px;color:#fff3d8;font-size:11px}
.guide-playback button:hover{background:#f6e9d437}

/* Noto Serif SC font license
Copyright 2012 Google Inc. All Rights Reserved.

This Font Software is licensed under the SIL Open Font License,
Version 1.1.

This license is copied below, and is also available with a FAQ at:
http://scripts.sil.org/OFL

-----------------------------------------------------------
SIL OPEN FONT LICENSE Version 1.1 - 26 February 2007
-----------------------------------------------------------

PREAMBLE
The goals of the Open Font License (OFL) are to stimulate worldwide
development of collaborative font projects, to support the font
creation efforts of academic and linguistic communities, and to
provide a free and open framework in which fonts may be shared and
improved in partnership with others.

The OFL allows the licensed fonts to be used, studied, modified and
redistributed freely as long as they are not sold by themselves. The
fonts, including any derivative works, can be bundled, embedded,
redistributed and/or sold with any software provided that any reserved
names are not used by derivative works. The fonts and derivatives,
however, cannot be released under any other type of license. The
requirement for fonts to remain under this license does not apply to
any document created using the fonts or their derivatives.

DEFINITIONS
"Font Software" refers to the set of files released by the Copyright
Holder(s) under this license and clearly marked as such. This may
include source files, build scripts and documentation.

"Reserved Font Name" refers to any names specified as such after the
copyright statement(s).

"Original Version" refers to the collection of Font Software
components as distributed by the Copyright Holder(s).

"Modified Version" refers to any derivative made by adding to,
deleting, or substituting -- in part or in whole -- any of the
components of the Original Version, by changing formats or by porting
the Font Software to a new environment.

"Author" refers to any designer, engineer, programmer, technical
writer or other person who contributed to the Font Software.

PERMISSION & CONDITIONS
Permission is hereby granted, free of charge, to any person obtaining
a copy of the Font Software, to use, study, copy, merge, embed,
modify, redistribute, and sell modified and unmodified copies of the
Font Software, subject to the following conditions:

1) Neither the Font Software nor any of its individual components, in
Original or Modified Versions, may be sold by itself.

2) Original or Modified Versions of the Font Software may be bundled,
redistributed and/or sold with any software, provided that each copy
contains the above copyright notice and this license. These can be
included either as stand-alone text files, human-readable headers or
in the appropriate machine-readable metadata fields within text or
binary files as long as those fields can be easily viewed by the user.

3) No Modified Version of the Font Software may use the Reserved Font
Name(s) unless explicit written permission is granted by the
corresponding Copyright Holder. This restriction only applies to the
primary font name as presented to the users.

4) The name(s) of the Copyright Holder(s) or the Author(s) of the Font
Software shall not be used to promote, endorse or advertise any
Modified Version, except to acknowledge the contribution(s) of the
Copyright Holder(s) and the Author(s) or with their explicit written
permission.

5) The Font Software, modified or unmodified, in part or in whole,
must be distributed entirely under this license, and must not be
distributed under any other license. The requirement for fonts to
remain under this license does not apply to any document created using
the Font Software.

TERMINATION
This license becomes null and void if any of the above conditions are
not met.

DISCLAIMER
THE FONT SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO ANY WARRANTIES OF
MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT
OF COPYRIGHT, PATENT, TRADEMARK, OR OTHER RIGHT. IN NO EVENT SHALL THE
COPYRIGHT HOLDER BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
INCLUDING ANY GENERAL, SPECIAL, INDIRECT, INCIDENTAL, OR CONSEQUENTIAL
DAMAGES, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
FROM, OUT OF THE USE OR INABILITY TO USE THE FONT SOFTWARE OR FROM
OTHER DEALINGS IN THE FONT SOFTWARE.

*/