:root{--ink:#30271f;--gold:#cda66b;--cream:#f5ebd9;--muted:#b5a690;--dark:#241e19;--icons:url('assets/icons.png');font-family:'Microsoft YaHei','PingFang SC',sans-serif;color:var(--cream);background:#1c1814;color-scheme:dark}*{box-sizing:border-box}html,body,#app{width:100%;height:100%;margin:0;overflow:hidden}button{font:inherit;color:inherit;border:0;cursor:pointer;-webkit-tap-highlight-color:transparent}button:focus-visible,[tabindex]:focus-visible{outline:3px solid #e1c28a;outline-offset:5px}button:disabled{opacity:.25;cursor:default}button{transition:background .2s,transform .2s,box-shadow .2s}button:hover:not(:disabled){filter:brightness(1.15)}button:active:not(:disabled){transform:scale(.97)}[hidden]{display:none!important}.screen{width:100%;height:100%;position:absolute;inset:0;display:flex;flex-direction:column;background:radial-gradient(ellipse at 50% 32%,#46392b 0%,#2b241e 50%,#1c1814 100%)}.screen.active{animation:arrive .45s ease both}@keyframes arrive{from{opacity:0}to{opacity:1}}.sprite{display:inline-block;flex-shrink:0;width:48px;height:48px;background-image:var(--icons);background-size:300% 200%;background-repeat:no-repeat;pointer-events:none}.magnify{background-position:0% 0%}.doorway{background-position:50% 0%}.collection{background-position:100% 0%}.back{background-position:0% 100%}.water{background-position:50% 100%}.expand{background-position:100% 100%}.icon-button{width:52px;height:52px;display:grid;place-items:center;border-radius:50%;background:#302820c9;border:1px solid #c2a47442;box-shadow:0 5px 20px #0002}.icon-button .sprite{width:43px;height:43px}.chevron{display:inline-block;width:11px;height:11px;transform:rotate(-45deg);border-right:2px solid currentColor;border-bottom:2px solid currentColor;rotate:90deg;margin:0 4px}.chevron.left{rotate:270deg}.hall-shade{pointer-events:none;position:absolute;inset:0;background:linear-gradient(0deg,#18120cc9,transparent 25%,transparent 85%,#18120c55)}#panorama{position:absolute;inset:0;overflow:hidden;cursor:grab;touch-action:none;background:#17130f}#panorama.dragging{cursor:grabbing}#hallImage{position:absolute;left:50%;top:50%;max-width:none;user-select:none;will-change:transform}#hall .hall-tools{position:absolute;right:26px;top:22px;display:flex;gap:12px}.hall-entry{position:absolute;bottom:6vh;left:50%;transform:translateX(-50%);text-align:center}.enter{background:linear-gradient(140deg,#5a3624,#2a2018);border:1px solid #d2ac6c;border-radius:60px;box-shadow:0 12px 35px #0008,inset 0 0 0 4px #eac7950d;padding:6px 32px 6px 12px;display:flex;align-items:center;gap:15px;font-size:21px;letter-spacing:3px;white-space:nowrap}.enter .sprite{width:72px;height:72px}.hall-entry p{font-size:12px;letter-spacing:3px;color:#e4d6bfbb;margin:14px 0 0}header{height:94px;padding:20px 30px;display:flex;align-items:center;justify-content:space-between;flex-shrink:0;border-bottom:1px solid #d3b57c15}h1{font-family:'Songti SC','SimSun',serif;font-size:23px;letter-spacing:5px;font-weight:normal;display:flex;align-items:center;margin:0}h1 small{font-family:'Microsoft YaHei',sans-serif;font-size:13px;letter-spacing:3px;color:var(--muted)}.thin-divider{width:1px;height:18px;background:#baa0785c;margin:0 20px}.art-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:clamp(16px,3vw,52px);flex:1;min-height:0;padding:30px 5vw 12px;align-items:center}.art-card{height:100%;min-height:0;display:flex;flex-direction:column;align-items:center;justify-content:center;background:transparent;position:relative;padding:0}.art-card .frame{width:100%;height:min(56vh,590px);padding:14px;background:linear-gradient(125deg,#b18d5e,#6c4d2e 4px,#e3c89b 7px,#7e5935 9px,#f0e5d0 10px);box-shadow:0 18px 34px #0007;transition:transform .3s,box-shadow .3s;display:flex;align-items:center;justify-content:center}.art-card:hover .frame{transform:translateY(-7px);box-shadow:0 26px 48px #0009}.art-card img{width:100%;height:100%;object-fit:contain;background:#e9dfcd}.art-card .card-foot{margin-top:20px;color:#bda98b;font:14px Georgia,serif;letter-spacing:3px;display:flex;align-items:center;gap:10px}.art-card .card-foot .sprite{width:34px;height:34px}.art-card.seen .card-foot:after{content:'✓';color:#b8cdb9;font-size:14px}.overview-footer{height:94px;padding:15px 5vw 25px;display:flex;align-items:center;justify-content:space-between;flex-shrink:0}.hint{font-size:12px;letter-spacing:2px;color:var(--muted)}.primary,.water-button,.next-button{background:#e5c48c14;border:1px solid #baa07855;border-radius:40px;display:flex;align-items:center;justify-content:center;gap:10px;padding:8px 20px;letter-spacing:2px;font-size:14px}.primary .sprite{width:38px;height:38px}.header-actions{display:flex;gap:12px}.progress{position:absolute;left:50%;transform:translateX(-50%);display:flex;align-items:center;gap:20px;font:17px Georgia,serif;letter-spacing:3px;color:#e2cfac}.dots{display:flex;gap:7px}.dots i{width:6px;height:6px;background:#756854;border-radius:50%;display:block}.dots i.on{background:#e8c486;box-shadow:0 0 10px #e8c48688}.view-body{flex:1;min-height:0;display:flex;gap:30px;padding:22px 6vw 8px}.art-area{flex:1;min-width:0;position:relative;overflow:hidden;display:flex;align-items:center;justify-content:center;touch-action:none;border-radius:3px}.art-canvas{position:absolute;transform-origin:center;user-select:none;box-shadow:0 8px 32px #0008;border:1px solid #ccad734d;will-change:transform}.art-canvas>img{display:block;width:100%;height:100%;pointer-events:none}#spots{position:absolute;inset:0;pointer-events:none}.spot{position:absolute;transform:translate(-50%,-50%);border:1px solid #fff5d2;border-radius:50%;width:36px;height:36px;background:#153945b0;box-shadow:0 0 0 5px #fff1c51a,0 3px 10px #0006;pointer-events:auto;display:grid;place-items:center}.spot .sprite{width:32px;height:32px}.spot:after{content:'';position:absolute;inset:-7px;border:1px solid #ffebae70;border-radius:50%;animation:ripple 3s ease-out infinite}.spot:active{transform:translate(-50%,-50%) scale(.96)}@keyframes ripple{0%{transform:scale(.8);opacity:.9}100%{transform:scale(1.4);opacity:0}}#regionBox{position:absolute;border:2px solid #ffe2a1;box-shadow:0 0 0 1px #654822aa;pointer-events:none;border-radius:2px}.detail-panel{flex:0 0 43%;min-width:0;display:flex;flex-direction:column;justify-content:center;animation:arrive .4s ease}.detail-top{display:flex;align-items:center;gap:12px;height:60px;font-size:16px;letter-spacing:4px;color:#dec99e}.detail-top .sprite{width:42px;height:42px}.close-button{margin-left:auto;background:transparent;font-size:30px;color:#bead92;width:44px;height:44px}.detail-viewport{position:relative;overflow:hidden;width:100%;height:min(42vh,440px);border:1px solid #c8a76980;box-shadow:0 14px 40px #0005;background:#182927;touch-action:none;cursor:grab}.detail-viewport img{position:absolute;max-width:none;user-select:none;pointer-events:none}.region-choices{display:flex;justify-content:center;gap:12px;padding:18px 0 8px}.region-choice{width:64px;height:42px;padding:0;position:relative;overflow:hidden;background:#254047;border:2px solid #ccb38633;border-radius:3px;opacity:.65}.region-choice.active{border-color:#efcf94;opacity:1}.region-choice img{position:absolute;max-width:none;pointer-events:none}.detail-controls{display:flex;gap:12px;justify-content:center;margin-top:6px}.detail-controls button{width:42px;height:38px;font-size:22px;border:1px solid #bda47755;background:#dfcba710;border-radius:25px}.viewer-footer{height:96px;display:flex;align-items:center;justify-content:space-between;padding:14px 5vw 24px;flex-shrink:0}.nav-button{height:50px;width:50px;border-radius:50%;border:1px solid #baa07855;background:#e5c48c14}.view-actions{display:flex;align-items:center;gap:20px}.water-button{padding:3px 16px 3px 5px}.water-button .sprite{width:40px;height:40px}.water-button.active{background:#497c7a44;border-color:#7bafaa}.next-button{min-width:130px;height:50px}.view-body.detail-mode .art-canvas{box-shadow:0 8px 30px #0006}#toast{position:fixed;left:50%;bottom:110px;transform:translateX(-50%);background:#1d1814ed;border:1px solid #b7946055;border-radius:25px;padding:12px 24px;opacity:0;pointer-events:none;font-size:13px;transition:opacity .2s;z-index:50}#toast.show{opacity:1}@media(max-width:850px){header{height:74px;padding:12px 18px}h1{font-size:19px;letter-spacing:3px}h1 small{font-size:11px}.art-grid{gap:18px;padding:20px 4vw}.art-card .frame{padding:10px;height:49vh}.overview-footer{height:80px;padding:8px 4vw 18px}.view-body{padding:14px 20px 0;gap:18px}.viewer-footer{height:80px;padding:12px 22px}.view-actions>.hint{display:none}.icon-button{width:46px;height:46px}.progress{gap:10px}.detail-panel{flex-basis:46%}.detail-viewport{height:38vh}.art-card .card-foot{margin-top:12px}.primary{font-size:12px;padding:6px 12px}}@media(max-width:580px) and (orientation:portrait){.art-grid{grid-template-columns:1fr 1fr;gap:20px;padding:14px 22px}.art-card .frame{height:26vh}.art-card .card-foot{margin-top:4px}.art-card .card-foot .sprite{width:24px;height:24px}.thin-divider,h1 small{display:none}.overview-footer>.hint{font-size:10px;letter-spacing:0}.view-body.detail-mode{flex-direction:column;gap:6px}.view-body.detail-mode .art-area{min-height:28vh;flex:1}.detail-panel{flex:0 0 auto}.detail-top{height:34px;font-size:13px}.detail-top .sprite{width:26px;height:26px}.detail-viewport{height:24vh}.region-choices{padding:8px 0 4px}.detail-controls{position:absolute;right:26px;bottom:100px;gap:6px}.detail-controls button{background:#211c16dc;width:32px;height:32px}.viewer-footer{padding:10px 16px;height:78px}.next-button{min-width:105px;font-size:12px}.water-button{font-size:12px;gap:2px;padding-right:10px}.nav-button{width:42px;height:42px}.progress{font-size:13px}.dots{display:none}.header-actions{gap:6px}.hall-entry{bottom:9vh}}@media(prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important}}
#panoCanvas{display:block;width:100%;height:100%;touch-action:none}.rotation-cue{position:absolute;left:28px;bottom:36px;display:flex;align-items:center;gap:12px;border:1px solid #d5b47a66;background:#22180fbb;border-radius:30px;padding:4px 10px;color:#e6d1ae;font:14px Georgia,serif;letter-spacing:2px}.rotation-cue button{background:transparent;font-size:26px;width:32px;height:34px}.chevron{rotate:0deg}.chevron.left{rotate:180deg}.art-card .frame{background:#eee3ce;border:5px solid #a68150;box-shadow:inset 0 0 0 2px #e4c898,0 18px 34px #0007}

/* Teaching revision: one continuous gallery, original-image zoom. */
:root{--gallery:url('assets/gallery.png')}
#overview,#viewer{background-image:linear-gradient(#30251b24,#30251b24),var(--gallery);background-position:center;background-size:cover}
#overview header,#viewer header{background:#332a20bd;border-bottom:1px solid #e6d4b75c;backdrop-filter:blur(10px)}
#overview footer,#viewer footer{background:linear-gradient(transparent,#30261bd9);color:#fff1d8}
#overview .hint,#viewer .hint,h1 small{color:#f4e6cf}
.art-grid{padding:18px 5vw 2px;gap:clamp(16px,3vw,48px)}
.art-card .frame{height:min(53vh,570px);box-shadow:0 12px 26px #22140780,inset 0 0 0 2px #e4c898}
.art-card .card-foot{margin-top:10px;color:#fff4dd;background:#342719b8;border-radius:24px;padding:0 10px}
.teaching-keywords{display:flex;justify-content:center;gap:30px;padding:14px 20px 6px;flex-shrink:0}
.teaching-keywords>span{display:flex;align-items:center;gap:12px;background:#fff1d9f2;color:#583d27;border:1px solid #cbb08a;border-radius:9px;padding:12px 25px;font-size:clamp(17px,1.8vw,25px);font-weight:600;letter-spacing:3px;box-shadow:0 4px 16px #28190f33}
.color-marks{width:13px;height:13px;background:#d54631;border-radius:50%;box-shadow:10px -7px #e9b725,12px 8px #3a916b;margin-right:10px}
.composition-mark{width:23px;height:23px;border:3px solid #b38953;background:repeating-linear-gradient(90deg,transparent 0 5px,#b38953 5px 7px);border-radius:3px}
.water-mark{font-style:normal;color:#3b817e;font-size:32px;line-height:20px}
.overview-footer{height:80px}
.primary,.next-button,.water-button,.nav-button{background:#3d3027dc;border-color:#e0c89b88}
.view-body{position:relative;display:block;padding:18px 5vw 8px}
.art-area{width:100%;height:100%;cursor:grab}
.art-area.dragging{cursor:grabbing}
.art-canvas.animating{transition:transform .8s cubic-bezier(.22,.7,.25,1)}
#regionBox{border:3px solid #ffe19b;border-radius:50%;box-shadow:0 0 0 1px #64422470;background:transparent}
.detail-toolbar{position:absolute;z-index:5;bottom:18px;left:50%;transform:translateX(-50%);display:flex;align-items:center;gap:18px;padding:8px 12px;border:1px solid #dfc69788;background:#32281eea;backdrop-filter:blur(12px);border-radius:12px;box-shadow:0 8px 25px #0004}
.detail-toolbar .region-choices{padding:0;gap:8px}.detail-toolbar .detail-controls{position:static;margin:0;gap:6px}
.return-art{background:#ede0c5;color:#513923;border-radius:20px;padding:9px 14px;white-space:nowrap;font-size:13px}
.detail-mode .art-canvas{box-shadow:0 8px 30px #0006}
@media(max-width:850px){.teaching-keywords{gap:14px;padding-top:10px}.teaching-keywords>span{font-size:17px;padding:9px 14px;gap:8px;letter-spacing:1px}.art-card .frame{height:48vh}.detail-toolbar{gap:10px}.viewer-footer .view-actions{gap:8px}}
@media(max-width:580px) and (orientation:portrait){.art-grid{padding:8px 22px;gap:12px}.art-card .frame{height:25vh}.teaching-keywords{gap:7px;padding:8px}.teaching-keywords>span{font-size:13px;padding:9px 8px;gap:4px;letter-spacing:0}.teaching-keywords i{display:none}.view-body.detail-mode{display:block;padding:14px 20px 0}.view-body.detail-mode .art-area{height:100%}.detail-toolbar{gap:8px;padding:7px;max-width:96%;bottom:10px}.region-choice{width:42px;height:32px}.detail-toolbar .detail-controls button{width:30px;height:30px}.return-art{font-size:11px;padding:8px}.overview-footer{height:68px}}
@media(max-height:600px) and (orientation:landscape){header{height:62px;padding:8px 20px}.overview-footer,.viewer-footer{height:64px;padding:8px 4vw}.teaching-keywords{padding:4px}.teaching-keywords>span{font-size:16px;padding:7px 20px}.art-card .frame{height:49vh}.art-card .card-foot{margin-top:4px}.art-grid{padding-top:8px}.detail-toolbar{bottom:12px}}
/* Teacher-controlled reveal; reserve its space so paintings do not move. */
.keywords-slot{height:clamp(112px,9.5vw,220px);flex-shrink:0;display:flex;align-items:center;justify-content:center}
.teaching-keywords{width:94%;display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:3vw;padding:0}
.teaching-keywords>span{position:relative;justify-content:center;min-width:0;height:clamp(96px,8.4vw,195px);font-size:clamp(34px,4.2vw,108px);padding:12px 20px;letter-spacing:.04em;font-weight:700;white-space:nowrap;color:#1262b5;background:var(--keyword-frame) center/100% 100% no-repeat;border:0;border-radius:0;box-shadow:none;filter:drop-shadow(0 6px 9px #173a263b);font-family:'Microsoft YaHei','PingFang SC',sans-serif;text-shadow:0 1px 0 #fff9}
.teaching-keywords>span>i{display:none}
#overview .art-card .frame{height:min(53vh,calc(100vh - 238px - clamp(112px,9.5vw,220px)))}
.keyword-toggle{min-height:48px;font-size:16px;padding:10px 22px}
@media(max-width:850px){.keywords-slot{height:92px}.teaching-keywords{gap:2vw;width:96%}.teaching-keywords>span{height:82px;font-size:4.3vw;padding:10px 8px;letter-spacing:.02em}}
@media(max-width:580px) and (orientation:portrait){.keywords-slot{height:78px}.teaching-keywords{gap:4px;width:98%}.teaching-keywords>span{height:68px;font-size:4.5vw;padding:8px 4px;letter-spacing:0}#overview .art-card .frame{height:25vh}.keyword-toggle{min-height:40px;font-size:13px;padding:8px 12px}}
@media(max-height:600px) and (orientation:landscape){.keywords-slot{height:86px}.teaching-keywords>span{height:80px;font-size:4vw;padding:10px 12px}#overview .art-card .frame{height:min(44vh,calc(100vh - 264px))}.keyword-toggle{min-height:40px;font-size:14px}}