:root{font-family:"Trebuchet MS","Microsoft YaHei",sans-serif;color:#253e37;background:#fcf8ed;--muted:#6a7869;--accent:#246251}
[hidden]{display:none!important}button,a,input{touch-action:manipulation}button{transition:transform .18s,background .18s}button:active{transform:translateY(2px) scale(.98)}button:focus-visible,a:focus-visible,input:focus-visible,summary:focus-visible{outline:3px solid #bd4930;outline-offset:5px}
header{height:88px;border-color:#dce0cd;max-width:1440px;margin:auto;padding:0 36px}.brand{font-size:21px}.exhibit-nav{color:#456051}main{max-width:1440px;padding:0 36px}.eyebrow{font-size:11px;letter-spacing:2px;color:#5e7665;font-weight:600}
.play-hero{display:grid;grid-template-columns:1.2fr 1fr;gap:25px;min-height:405px;align-items:center;padding:42px 32px 50px}.hero-copy h1{font-family:inherit;font-size:clamp(40px,4.5vw,66px);line-height:1.2;letter-spacing:-2px;font-weight:800;margin:19px 0}.hero-copy h1>span{color:#267463}.hero-copy p{font-size:15px;line-height:1.9;color:#617161;margin:0 0 24px}.hero-copy>button{border:0;background:#286452;color:#fff;padding:16px 22px;border-radius:12px;font-size:15px;font-weight:600;box-shadow:0 5px 0 #173f34}.hero-copy>button span{margin-left:35px}.hero-copy>small{font-size:11px;margin-left:20px;color:#697c6b}.hero-art{position:relative;min-height:315px;display:grid;place-items:center}.orbit{position:absolute;width:330px;height:165px;border:1px dashed #99b49a;border-radius:50%;transform:rotate(-28deg)}.orbit-two{transform:rotate(46deg);width:275px;height:275px;border-color:#d2d8be}.buddy{position:relative;display:flex;width:98px;height:110px;border:2px solid #304b3e;border-radius:28px 28px 36px 36px;background:#fff7d2;color:#304b3e;align-items:center;justify-content:center;box-shadow:5px 7px 0 #304b3e20;transform:rotate(-7deg);flex-shrink:0}.buddy>b{font-size:43px;letter-spacing:-3px;line-height:1;transform:translateY(-12px)}.eyes{position:absolute;top:69%;left:35%;width:6px;height:9px;background:currentColor;border-radius:5px;box-shadow:23px 0 currentColor}.smile{position:absolute;width:13px;height:6px;left:45%;top:82%;border-bottom:2px solid;border-radius:50%}.hero-buddy{width:178px;height:194px;background:#ecc26f;border-radius:52px;transform:rotate(-12deg);box-shadow:12px 16px 0 #374e3520;animation:hello 1.1s ease both}.hero-buddy>b{font-size:90px}.hero-buddy .eyes{width:9px;height:14px;box-shadow:43px 0 currentColor}.hero-buddy .smile{width:23px;height:9px}.mini-buddy{position:absolute;bottom:35px;right:40px;display:flex;flex-direction:column;align-items:center;background:#96cdbd;border:2px solid #304b3e;border-radius:32px;width:90px;height:94px;font-size:39px;font-weight:600;transform:rotate(13deg)}.mini-buddy span{font-size:34px;line-height:14px}.hero-star{position:absolute;top:17px;right:34px;font-size:50px;color:#d77a51}.hero-bubble{position:absolute;top:4px;left:24px;background:#fffef7;border:1px solid #bbc8ad;border-radius:15px 15px 2px 15px;padding:12px 16px;font-size:13px;transform:rotate(-6deg)}.hero-caption{position:absolute;bottom:-8px;font-size:11px;letter-spacing:4px;color:#72816b}
.explore-toolbar{border-top:1px solid #d9dfcd;border-bottom:1px solid #d9dfcd;display:flex;align-items:center;justify-content:space-between;padding:14px 0;gap:16px}.view-switch{display:flex;gap:8px}.view-switch button{padding:12px 16px;border:0;background:transparent;border-radius:9px;font-size:14px;color:#5f7362}.view-switch button[aria-pressed=true]{background:#2d6150;color:white}.view-switch span{font-size:10px;margin-left:7px;opacity:.8}.passport-link{font-size:12px;padding:10px}.section-heading{display:flex;align-items:end;justify-content:space-between;gap:20px;padding:38px 0 24px}.section-heading h2,.routes h2,.passport h2,#periodic h2{font-family:inherit;font-size:25px;font-weight:700;margin:10px 0 0}.section-heading p{font-size:12px;color:#6d7c6d;margin:0 0 3px}
#discovery-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px}.discovery-card{display:flex;position:relative;flex-direction:column;min-height:305px;text-align:left;padding:20px;background:var(--card);color:#2a453a;border:0;border-radius:19px;overflow:hidden;animation:arrive .5s both;animation-delay:var(--delay)}.discovery-card:hover{transform:translateY(-5px);box-shadow:0 7px 0 #2745311c}.card-meta{display:flex;width:100%;justify-content:space-between;gap:5px;font-size:11px;font-weight:600}.card-meta>span{font-size:10px;font-weight:400}.discovery-card>.buddy{align-self:center;margin:20px 0 18px;background:#fff8;transition:transform .25s}.discovery-card:hover>.buddy{transform:rotate(5deg) translateY(-5px)}.card-copy{display:flex;flex-direction:column;flex:1}.card-copy>strong{font-size:19px;line-height:1.45;text-wrap:balance;letter-spacing:-.5px}.card-copy>span{font-size:12px;line-height:1.7;margin-top:10px;opacity:.85}.card-copy>b{display:flex;justify-content:space-between;font-size:12px;font-weight:500;margin-top:auto;padding-top:22px}.featured{grid-column:span 2;display:grid;grid-template-columns:1fr 150px;column-gap:12px}.featured .card-meta{grid-column:span 2}.featured .buddy{grid-column:2;grid-row:2;width:130px;height:146px;justify-self:center;align-self:center;transform:rotate(9deg)}.featured .buddy>b{font-size:65px}.featured .card-copy{grid-column:1;grid-row:2;align-self:center}.featured .card-copy>strong{font-size:29px}.featured .card-copy>b{padding-top:24px}.featured .eyes{box-shadow:30px 0 currentColor}
.routes{display:grid;grid-template-columns:1.1fr 1fr 1fr;gap:20px;align-items:center;padding:42px 0}.routes h2{font-size:23px;max-width:220px;line-height:1.5}.routes>button{position:relative;text-align:left;background:#f1eedf;border:1px dashed #b5bba1;border-radius:15px;padding:23px;color:#395a46}.routes b,.routes span,.routes small{display:block}.routes b{font-size:14px}.routes span{font-size:13px;margin-top:11px}.routes small{font-size:11px;margin-top:10px;color:#617459}.routes i{position:absolute;right:18px;top:20px;font-style:normal;font-size:23px}.routes>button:hover{background:#e6ecd7}
.passport{display:grid;grid-template-columns:1fr 1fr;gap:40px;background:#e9eedf;border-radius:18px;padding:30px;margin:4px 0 35px}.passport p{font-size:13px;line-height:1.8;color:#607459}.passport>div>small{font-size:11px;color:#69785f}.passport-total{display:flex;align-items:center;justify-content:space-between;font-size:12px}.passport-total b{font-size:22px;font-variant-numeric:tabular-nums}progress{width:100%;height:7px;accent-color:#376b54;margin:14px 0;border:0;border-radius:8px;overflow:hidden}progress::-webkit-progress-bar{background:#d7dfca}progress::-webkit-progress-value{background:#376b54;border-radius:8px}#stamp-row{display:grid;grid-template-columns:repeat(8,1fr);gap:7px}.stamp{border:1px dashed #aab79b;border-radius:50%;aspect-ratio:1;background:transparent;color:#708464;display:flex;align-items:center;justify-content:center;flex-direction:column;font-weight:600}.stamp small{font-size:10px}.stamp.earned{background:#33614e;color:#fff;border-style:solid;transform:rotate(-7deg)}#periodic{padding-top:30px}.element{background:#fffdf6;border-color:#e6e7d4;box-shadow:0 3px 0 #dadfcc}.element:hover{background:#e5efd8}.invitation button{color:#42745d}.invitation p{color:#61735d}footer{border-color:#d9dfcd;line-height:1.8}
dialog{background:#fcf8ed}.detail-bar{background:#fcf8edf5}.play-lab{margin:25px 32px 0;display:grid;grid-template-columns:.85fr 1.15fr;gap:20px 30px;background:var(--card);border-radius:20px;padding:30px}.lab-intro>span{font-size:11px;letter-spacing:2px}.lab-intro h3{font-family:inherit;font-size:29px;line-height:1.4;font-weight:700;margin:15px 0}.lab-intro p{font-size:14px;color:#3e594e}.lab-stage{background:#ffffff70;border-radius:15px;padding:18px;text-align:center;min-width:0}.play-action{display:inline-block;background:#2c604f;color:#fff;border:0;border-radius:8px;padding:12px 18px;font-size:13px;min-height:44px}.model-note{display:block;font-size:10px;line-height:1.6;color:#506454;margin-top:12px}.experiment-status{font-size:12px;line-height:1.7!important;margin-top:10px!important;min-height:22px}.quiz{grid-column:1/-1;border-top:1px solid #3c5b3325;padding-top:10px}.quiz h4{font-size:16px;margin:10px 0 14px}.quiz-options{display:flex;gap:10px;flex-wrap:wrap}.quiz-options button{flex:1;padding:13px 15px;min-height:46px;background:#fff9;border:2px solid transparent;border-radius:9px;color:#324e42;font-size:13px}.quiz-options button:hover{background:#fff}.quiz-options .correct{border-color:#32704e;background:#e5f4df}.quiz-options .try-again{border-color:#b76b30}.quiz-feedback{font-size:13px;line-height:1.9;margin-top:14px}.reward{display:flex;gap:15px;margin-top:15px;flex-wrap:wrap}.reward button{padding:13px 20px;border-radius:8px;background:#2b5f4b;color:#fff;border:0;font-size:13px}.reward .next-discovery{background:#fff9;color:#2b5f4b}.celebrate .collect-stamp{animation:stamp-pop .5s ease}.detail-layout{border-top:1px solid #dce0ce;margin-top:30px}.photo>a{background:#e8e9de}.detail-layout h2{font-family:inherit}.specimen{background:#e9eddc;border-radius:15px;box-shadow:none}.story-title{font-family:inherit}.photo-note{color:#6b7760}.reading-label{color:#32745c}
.circuit{position:relative;height:114px;width:210px;margin:12px auto 22px;border:5px solid #bc7b56;border-radius:16px}.battery{position:absolute;left:-20px;top:20px;width:34px;height:58px;border:2px solid #3e5648;background:#cbdcb8;border-radius:5px;line-height:22px}.bulb{position:absolute;right:-27px;top:24px;border:3px solid #53634e;width:48px;height:48px;border-radius:50%;background:#d3d5c5;font-size:29px;color:#869174;line-height:40px}.wire{position:absolute;top:-5px;left:75px;width:65px;height:5px;background:#345345;transform:rotate(-28deg);transform-origin:left;transition:transform .3s}.is-active .wire{transform:rotate(0)}.is-active .bulb{background:#ffe06b;box-shadow:0 0 28px #efb43d80;color:#856b1c}.weights{display:flex;justify-content:center;gap:38px;margin:8px 0 18px}.weights>div{display:flex;flex-direction:column;gap:8px;align-items:center}.cube{display:grid;place-items:center;width:56px;height:56px;border:2px solid #587268;border-radius:6px;background:#dbe8e6;font-size:22px;box-shadow:5px 5px #819a8d}.cube.copper{background:#e5ad80;box-shadow:5px 5px #ba8054}.weights strong{font-size:18px}.weights small{font-size:11px}.foil-tray{height:100px;display:grid;place-items:center;overflow:hidden;margin:10px auto 20px}.gold-foil{width:72px;height:65px;background:linear-gradient(135deg,#f1c64b,#ffe490 50%,#c59527);border:1px solid #b78929;display:grid;place-items:center;color:#745615;font-size:25px;border-radius:4px;transition:transform .12s}.slider-label{display:flex;justify-content:space-between;font-size:12px}#foil-range{width:100%;padding:12px 0;accent-color:#3a6a52;border:0;background:none;min-height:44px}.coin-face{width:122px;height:122px;display:grid;place-items:center;border-radius:50%;border:6px double #577055;background:#c0ccb0;margin:5px auto 18px;font-size:23px;transition:transform .6s}.is-active .coin-face{transform:rotate(360deg);font-size:14px;background:conic-gradient(#d8a17c 75%,#b5c6af 0)}.sky-stage{height:130px;position:relative}.helium-balloon{position:absolute;left:calc(50% - 32px);bottom:5px;width:64px;height:78px;border-radius:50%;background:#d8839e;border:2px solid #8c5067;display:grid;place-items:center;font-size:25px;color:#fff;transition:transform .8s}.helium-balloon::after{content:'';position:absolute;top:100%;height:28px;border-left:1px solid #8c5067}.is-active .helium-balloon{transform:translate(-30px,-38px) rotate(-10deg)}.sun-hint{position:absolute;right:25px;top:0;color:#a57328;font-size:38px}.air-box{display:grid;grid-template-columns:repeat(10,1fr);width:165px;gap:4px;margin:0 auto 17px}.air-box i{aspect-ratio:1;border-radius:50%;background:#aec1c3}.is-active .oxygen-dot{background:#22768b}.steel-stage{display:flex;align-items:center;justify-content:center;gap:15px;height:125px}.steel-stage span{font-size:28px}.steel-stage strong{font-size:22px;color:#385e50}.carbon-mini{display:flex;align-items:center;justify-content:center;gap:20px;height:120px}.carbon-mini span:first-child,.carbon-mini span:last-child{font-size:70px}.carbon-mini span:nth-child(2){font-size:12px}
@keyframes arrive{from{opacity:0;transform:translateY(12px)}to{opacity:1;transform:translateY(0)}}@keyframes hello{0%{transform:translateY(16px) rotate(-20deg);opacity:0}70%{transform:translateY(-5px) rotate(-7deg)}100%{transform:rotate(-12deg);opacity:1}}@keyframes stamp-pop{50%{transform:rotate(-4deg) scale(1.06)}}
@media(max-width:1100px){#discovery-grid{grid-template-columns:repeat(3,minmax(0,1fr))}.hero-copy>small{display:block;margin:17px 0 0}.play-hero{padding-left:0;padding-right:0}.routes{gap:12px}.routes>button{padding:20px 14px}.play-lab{gap:20px}.hero-bubble{left:0}.mini-buddy{right:0}.orbit{width:280px}}
@media(max-width:800px){header{padding:0 22px;margin:0;height:75px}main{padding:0 20px}.play-hero{min-height:0;grid-template-columns:1fr;position:relative;padding:30px 0 34px;overflow:hidden}.hero-copy{position:relative;z-index:1}.hero-copy h1{font-size:43px;max-width:350px}.hero-copy p{font-size:13px}.hero-art{position:absolute;width:140px;min-height:160px;right:0;top:42px;opacity:.9;pointer-events:none}.hero-buddy{width:95px;height:106px;border-radius:30px;box-shadow:7px 7px #374e3520}.hero-buddy>b{font-size:45px}.hero-buddy .eyes{width:5px;height:8px;box-shadow:23px 0 currentColor}.hero-buddy .smile{width:13px;height:6px}.hero-caption,.hero-bubble,.mini-buddy,.orbit-two{display:none}.orbit{width:155px;height:80px}.hero-star{font-size:25px;right:0;top:4px}.hero-copy h1>span{position:relative}.view-switch button{font-size:12px;padding:12px}.view-switch{gap:0}.passport-link{font-size:11px;padding:6px}.explore-toolbar{gap:6px}.section-heading{display:block;padding:28px 0 20px}.section-heading h2{font-size:23px}.section-heading p{margin-top:10px}.discovery-card{min-height:290px;padding:17px}#discovery-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}.featured{grid-column:span 2;min-height:245px}.card-copy>strong{font-size:17px}.featured .card-copy>strong{font-size:25px}.card-meta{font-size:11px;flex-wrap:wrap}.card-meta>span{font-size:10px}.routes{grid-template-columns:1fr 1fr;padding:30px 0}.routes>div{grid-column:span 2}.routes h2{max-width:none;font-size:21px;margin:8px 0}.routes>button{padding:20px 13px}.routes span{font-size:12px}.routes small{font-size:10px}.routes i{right:12px;top:12px}.passport{grid-template-columns:1fr;gap:22px;padding:24px 20px}.passport h2{font-size:24px}.passport p{margin-bottom:8px}.stamp{font-size:13px}.play-lab{grid-template-columns:1fr;margin:15px 16px 0;padding:20px;gap:15px}.lab-intro h3{font-size:25px;margin:10px 0}.lab-intro p{font-size:13px}.quiz{grid-column:1}.quiz-options{flex-direction:column;gap:8px}.quiz-options button{text-align:left}.lab-stage{padding:16px}.detail-layout{margin-top:24px}.detail-bar>span{font-size:10px}.photo img{height:100%}}
@media(max-width:410px){.hero-art{right:-26px;top:36px;transform:scale(.75)}.hero-copy h1{font-size:37px}.hero-copy p{font-size:12px}.eyebrow{font-size:10px;letter-spacing:1px}.featured{grid-template-columns:1fr 100px}.featured .buddy{width:85px;height:104px}.featured .buddy>b{font-size:45px}.featured .eyes{box-shadow:20px 0 currentColor}.featured .card-copy>strong{font-size:23px}.card-copy>span{font-size:11px}.discovery-card{padding:14px}.passport-link{font-size:10px}.view-switch button{padding:10px 8px}.view-switch span{margin-left:3px}}
@media(prefers-reduced-motion:reduce){*,*::before,*::after{animation:none!important;transition:none!important;scroll-behavior:auto!important}}

/* Clear circuit gap and comfortable reading targets. */
.circuit{border-top-color:transparent}.circuit::before{content:"";position:absolute;left:0;right:0;top:-5px;height:5px;background:linear-gradient(to right,#bc7b56 0 75px,transparent 75px 140px,#bc7b56 140px)}.quiz-options button{font-size:15px;min-height:50px}.play-action,.reward button{font-size:14px}.experiment-status,.quiz-feedback{font-size:14px}.lab-intro p{font-size:15px}.hero-buddy{animation-duration:.6s}

@media(max-width:800px){.discovery-card:last-child{grid-column:span 2;display:grid;grid-template-columns:1fr 100px;gap:16px;min-height:215px}.discovery-card:last-child .card-meta{grid-column:span 2}.discovery-card:last-child .buddy{grid-column:2;grid-row:2;justify-self:center;width:80px;height:100px}.discovery-card:last-child .card-copy{grid-column:1;grid-row:2}.discovery-card:last-child .eyes{box-shadow:19px 0 currentColor}#stamp-row{grid-template-columns:repeat(4,1fr);max-width:300px}.stamp{min-height:44px;max-width:58px}.routes h2{text-wrap:balance}}