.fw-wrap{width:var(--wrap);margin-inline:auto}
.fw-skip-link{position:fixed;left:16px;top:10px;z-index:999;transform:translateY(-150%);background:var(--blue);color:#fff;padding:10px 14px;border-radius:999px;font-weight:700}
.fw-skip-link:focus{transform:none}
.fw-site-header{position:sticky;top:0;z-index:100;background:rgba(245,249,251,.98);backdrop-filter:blur(16px);border-bottom:1px solid rgba(210,232,242,.9);box-shadow:0 4px 18px rgba(18,50,59,.045)}
.fw-nav{height:86px;display:flex;align-items:center;gap:30px;justify-content:space-between}
.fw-brand{display:flex;align-items:center;gap:10px;color:inherit;min-width:330px}
.fw-brand-logo{width:58px;height:58px;object-fit:contain;filter:drop-shadow(0 5px 10px rgba(0,69,155,.06));flex:0 0 58px}
.fw-brand-wordmark-img{width:245px;height:52px;object-fit:contain;object-position:left center;mix-blend-mode:normal;opacity:1;filter:none}
.fw-navlinks{display:flex;align-items:center;justify-content:flex-end;gap:30px;margin-left:auto}
.fw-navlinks>a{font-size:15px;color:#073c76;font-weight:700;white-space:nowrap;transition:color .2s ease}
.fw-navlinks>a:hover{color:var(--green)}
.fw-navlinks>a.fw-nav-cta{display:inline-flex;align-items:center;justify-content:center;margin-left:2px;padding:11px 17px;border-radius:999px;background:linear-gradient(180deg,#26b96a,#009d54);color:#fff;font-size:14px;font-weight:900;line-height:1.15;box-shadow:0 8px 20px rgba(0,111,58,.18);transition:transform .2s ease,box-shadow .2s ease,background .2s ease}
.fw-navlinks>a.fw-nav-cta:hover{color:#fff;transform:translateY(-1px);box-shadow:0 11px 24px rgba(0,111,58,.24)}
.fw-menu-toggle{display:none;background:none;border:0;padding:8px}
.fw-menu-toggle span{display:block;width:26px;height:2px;background:var(--blue);margin:5px 0;border-radius:2px}
.fw-site-footer{border-top:1px solid var(--line);padding:34px 0;color:var(--muted);font-size:14px;background:#fff}
.fw-footer-grid{display:grid;grid-template-columns:1fr 1.2fr 1fr;gap:25px;align-items:center}
.fw-footer-brand{display:flex;align-items:center;gap:11px}
.fw-footer-brand>img:first-child{width:46px;height:46px;object-fit:contain}
.fw-footer-wordmark{width:220px;height:auto;mix-blend-mode:normal;opacity:1;filter:none}
.fw-footer-center{text-align:center}
.fw-footer-center p{margin:3px 0}
.fw-ki-note{font-size:11px;line-height:1.35}
.fw-footer-links{display:flex;justify-content:flex-end;gap:14px;flex-wrap:wrap}
.fw-footer-links a{font-weight:700}
.fw-footer-grid>*{min-width:0}
.fw-navlinks a,.fw-footer-links a{touch-action:manipulation}
@media(max-width:1180px){.fw-nav{gap:14px}
.fw-brand{min-width:260px}
.fw-brand-wordmark-img{width:195px}
.fw-navlinks{gap:15px}
.fw-navlinks>a{font-size:14px}
.fw-footer-grid{grid-template-columns:1fr 1fr}
.fw-footer-center{grid-column:1/-1;grid-row:2}
}
@media(max-width:1200px){.fw-nav{height:78px;position:relative;gap:10px}
.fw-brand{min-width:0}
.fw-brand-wordmark-img{width:210px;height:auto}
html.js .fw-menu-toggle{display:block;min-width:44px;min-height:44px;cursor:pointer}
.fw-navlinks{position:absolute;top:calc(100% + 1px);right:0;left:0;background:#fff;box-shadow:0 14px 25px rgba(0,37,72,.15);border-radius:0 0 18px 18px;padding:16px;display:none;align-items:stretch;flex-direction:column;gap:6px}
.fw-navlinks.fw-is-open{display:flex}
.fw-navlinks>a{padding:12px;font-size:16px;white-space:normal}
.fw-navlinks>a.fw-nav-cta{margin:4px 0}
html:not(.js) .fw-nav{height:auto;min-height:78px;flex-wrap:wrap;padding:12px 0}
html:not(.js) .fw-navlinks{position:static;display:flex;flex-direction:row;flex-wrap:wrap;padding:4px 0;box-shadow:none;margin:0;width:100%}
}
@media(max-width:680px){.fw-nav{height:72px}
.fw-brand{gap:7px}
.fw-brand-logo{width:44px;height:44px;flex-basis:44px}
.fw-brand-wordmark-img{width:180px;height:auto}
.fw-footer-grid{grid-template-columns:1fr;gap:20px}
.fw-footer-brand{justify-content:center}
.fw-footer-center{grid-column:auto;grid-row:auto}
.fw-footer-links{justify-content:center}
.fw-footer-links a{padding:8px 2px}
}
@media(max-width:380px){.fw-brand-wordmark-img{width:160px}
}
.fw-fw-social-links,.fw-site-footer .fw-fw-social-links{display:flex;align-items:center;gap:12px;flex-wrap:wrap;margin:14px 0 0;padding:0}
.fw-fw-social-links .fw-fw-social-link,.fw-site-footer .fw-fw-social-links .fw-fw-social-link{box-sizing:border-box;display:inline-flex;align-items:center;justify-content:center;width:44px;height:44px;padding:0;border:1px solid #c9dfec;border-radius:50%;background:#f5fbff;color:#0a4b7a;text-decoration:none;transition:background .15s,color .15s,border-color .15s;flex:0 0 44px}
.fw-fw-social-links .fw-fw-social-link:hover,.fw-site-footer .fw-fw-social-links .fw-fw-social-link:hover{background:#008f67;color:#fff;border-color:#008f67}
.fw-fw-social-links .fw-fw-social-link:focus-visible{outline:3px solid #00a877;outline-offset:4px}
.fw-fw-social-links svg{display:block;width:24px;height:24px;flex:none}
.fw-footer-center .fw-fw-social-links{justify-content:center}
.fw-fw-main-footer .fw-footer-grid{grid-template-columns:minmax(0,1fr) auto minmax(0,1fr);gap:20px 25px}
.fw-fw-main-footer .fw-footer-brand{grid-column:1;grid-row:1}
.fw-fw-main-footer .fw-fw-social-links{grid-column:2;grid-row:1;justify-content:center;margin:0}
.fw-fw-main-footer .fw-footer-links{grid-column:3;grid-row:1}
.fw-fw-main-footer .fw-footer-center{grid-column:1/-1;grid-row:2}
@media(max-width:720px){.fw-fw-main-footer .fw-footer-grid{grid-template-columns:1fr;gap:18px}
.fw-fw-main-footer .fw-footer-brand{grid-column:1;grid-row:1;justify-content:center}
.fw-fw-main-footer .fw-fw-social-links{grid-column:1;grid-row:2}
.fw-fw-main-footer .fw-footer-links{grid-column:1;grid-row:3;justify-content:center}
.fw-fw-main-footer .fw-footer-center{grid-column:1;grid-row:4}
}

:root{--fw-header-height:86px;--mission-toolbar-height:78px;--wrap:min(1180px,92vw);--text:#12323b;--muted:#536a73;--green:#00a957;--line:#d2e8f2}
html{scroll-padding-top:calc(var(--fw-header-height) + var(--mission-toolbar-height) + 18px)}
.fw-site-header{z-index:120}
.fw-wrap{width:var(--wrap);margin-inline:auto}
.fw-navlinks a[aria-current="page"]{color:#008846;text-decoration:underline;text-underline-offset:5px}
.fw-navlinks a:focus-visible,.fw-footer-links a:focus-visible,.fw-menu-toggle:focus-visible{outline:3px solid #00a957;outline-offset:4px}
.fw-brand-logo,.fw-brand-wordmark-img,.fw-footer-brand img{display:block}
.fw-brand-wordmark-img{max-width:100%}
.fw-site-footer{color:#536a73;background:#fff;font-size:14px}
.fw-site-footer p{font-size:14px}
.fw-site-footer .fw-ki-note{font-size:11px;line-height:1.35}
.fw-footer-wordmark{max-width:220px;height:auto}
.mission-toolbar{top:var(--fw-header-height);z-index:110}
.mission-toolbar .nav-wrap{flex-wrap:wrap;padding-block:10px;min-width:0}
.mission-toolbar .main-nav.open{top:100%}
.mission-brand{min-width:0}
.mission-brand strong{font-size:1rem}
.mission-brand small{font-size:.65rem}
main [id]{scroll-margin-top:0}
.hero{background:linear-gradient(135deg,#f5fbff 0%,#eaf7ff 65%,#e9fbf2 100%)}
.hero h1{font-size:clamp(2.5rem,4.6vw,4.1rem);line-height:1.08}
.btn-primary{background:linear-gradient(180deg,#2b79c7,#0b5da8);color:#fff;box-shadow:0 8px 20px rgba(0,74,173,.18)}
.btn-primary:hover{background:#004aad}
.btn-secondary{border-color:#d2e8f2;color:#004aad}
.voice-status{font-weight:600}
main h1,main h2,main h3{overflow-wrap:anywhere}
.offer-cards{grid-template-columns:repeat(2,minmax(0,1fr))}
.offer-card,.offer-copy{min-width:0;overflow-wrap:anywhere}
@media(max-width:1200px){.fw-nav{height:78px}.fw-brand{min-width:0}.fw-brand-wordmark-img{width:210px;height:auto}}
@media(max-width:700px){.mission-toolbar .nav-wrap{gap:8px}.mission-brand{flex:1}.mission-brand strong{font-size:.85rem}.mission-brand small{display:none}.header-progress{display:flex;flex:0 0 100%;justify-content:center;font-size:.8rem}.header-bar{width:100px}.header-progress strong{display:block}.mission-menu-toggle,.icon-btn{min-height:44px;min-width:44px}.hero{padding-top:32px}.hero h1{font-size:clamp(2rem,10vw,3rem)}.offer-cards{grid-template-columns:minmax(0,1fr)}}
@media(max-width:680px){.fw-nav{height:72px}.fw-brand-wordmark-img{width:180px}}
@media(max-width:380px){.fw-brand-wordmark-img{width:160px}}

/* Readable answers and flexible touch targets, including completed quiz feedback. */
.quiz-card label,.final-question label{display:flex;align-items:flex-start;gap:10px;font-size:18px;line-height:1.5;min-height:48px;padding:10px 12px;margin-top:8px;border:1px solid #d2e8f2;border-radius:10px;background:#fff;cursor:pointer;overflow-wrap:break-word}
.quiz-card label input,.final-question label input{flex:0 0 20px;width:20px;height:20px;margin:3px 0 0;accent-color:#004aad}
.quiz-card label:focus-within,.final-question label:focus-within{outline:3px solid #004aad;outline-offset:2px}
.quiz-card label:has(input:checked),.final-question label:has(input:checked){border-color:#004aad;background:#edf6ff}
.quiz-card,.final-question,.panel,.quiz-result{min-width:0}
.hint-btn,.mini-btn,.mission-menu-toggle,.reset-progress-btn{min-height:44px;min-width:44px;height:auto}
.reset-progress-btn{display:inline-flex;align-items:center;padding:8px 12px}
.quiz-actions,.final-actions{flex-wrap:wrap;align-items:flex-start}
.quiz-actions .btn,.final-actions .btn{flex-shrink:0;min-height:48px;height:auto;white-space:normal}
.final-actions .quiz-result{flex:1 1 240px;overflow-wrap:break-word}
.mission-intro{font-size:18px;line-height:1.65;max-width:900px;margin:18px 0}
.voice-status,.quiz-result,.header-progress{font-size:16px;line-height:1.5}
.fw-site-footer .fw-ki-note{font-size:13px;line-height:1.5}
@media(max-width:700px){.final-actions{flex-direction:column;align-items:stretch}.final-actions .btn{width:100%}.final-actions .quiz-result{flex:0 1 auto}.hero h1{font-size:clamp(1.8rem,8vw,2.8rem)}.mission-intro{font-size:17px}}
.quiz-card label,.final-question label{font-size:18px!important}.hero-illustration{height:auto}.hero .lead{font-size:18px}.research-mini p{font-size:17px}.question-feedback{font-size:16px;line-height:1.5}

/* Give demonstrations and their descriptions separate, naturally sized rows. */
.interaction .visual-stage{display:flex;flex-direction:column;justify-content:center;align-items:stretch;gap:16px;padding:20px 14px;min-height:190px;overflow:visible}
.interaction .visual-stage>div{min-width:0;max-width:100%}
.interaction .stage-text{position:static;inset:auto;width:100%;margin:0;padding:12px;border:1px solid #d2e8f2;flex:0 0 auto;font-size:17px;line-height:1.5;overflow-wrap:break-word}
.interaction h4{padding-right:48px;min-height:36px;overflow-wrap:break-word}
.interaction .step-btn,.interaction .choice-btn{min-height:44px;white-space:normal}
.interaction .visual-stage+.btn{margin-top:14px;min-height:48px;white-space:normal}
.interaction .evidence-card,.interaction .tech-card{min-width:0;white-space:normal;overflow-wrap:break-word;font-size:17px;line-height:1.5}
.interaction .tech-detail{height:auto;min-height:0;font-size:17px;line-height:1.5;overflow-wrap:break-word}
.interaction .h2-zone{flex:0 0 190px;height:190px}
.interaction .h2-bubble{width:44px;height:44px}
.interaction .h2-bubble:nth-child(5){left:calc(100% - 52px)}
.interaction .ph-examples{margin-top:12px}
@media(max-width:600px){.interaction .compare-grid,.interaction .evidence-grid{grid-template-columns:minmax(0,1fr)}.interaction .electro-demo{grid-template-columns:minmax(0,1fr);text-align:center}.interaction .chamber{width:100%;max-width:320px;margin-inline:auto}.interaction .visual-stage{padding:16px 12px}}
.interaction .evidence-card,.interaction .evidence-card small,.interaction .tech-card{overflow-wrap:anywhere}
.interaction .filter-demo .raw{min-width:0;overflow:hidden}.interaction .filter-demo{min-width:0}

/* Electrolysis: separate external electrons, ion migration and gas formation. */
.electro-model{width:100%;min-width:0}
.electro-power{background:#fff;border:2px solid #004aad;border-radius:12px;padding:10px;text-align:center;font-weight:800;color:#12323b}
.electro-power span{display:block;font-size:14px;font-weight:600}
.electron-circuits{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px;margin:10px 0}
.electron-route{position:relative;display:flex;align-items:center;gap:6px;min-height:66px;padding:8px 7px 8px 16px;border-left:3px solid #004aad;color:#12323b;overflow:hidden}
.electron-route strong{font-size:19px;flex:0 0 auto}.electron-route span{font-size:14px;line-height:1.5;overflow-wrap:anywhere}
.electron-route i{position:absolute;left:-1px;top:48px;width:8px;height:8px;border-radius:50%;background:#004aad}
.electro-cell{position:relative;border:3px solid #7bb5cf;border-radius:20px;background:#eaf8fc;padding:12px 10px;overflow:hidden}
.electro-side-labels{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:8px;text-align:center;font-size:16px;position:relative;z-index:2}
.electro-gases{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:8px;margin:10px 0 15px;position:relative;z-index:2}
.electro-gases>div>span{display:block;text-align:center;font-size:14px;color:#12323b;line-height:1.5}
.electro-gases>div>div{display:flex;justify-content:center;flex-wrap:wrap;gap:4px;min-height:62px;align-content:center}
.electro-gas{display:grid;place-items:center;flex:0 0 28px;width:28px;height:28px;background:#298fba;border-radius:50%;font-size:12px;font-weight:bold;color:#fff}
.electro-gases>div:first-child .electro-gas{background:#358578}
.electro-poles{position:absolute;left:10px;right:10px;bottom:12px;display:flex;justify-content:space-between;pointer-events:none;z-index:2}
.electro-poles span{display:grid;place-items:center;width:24px;height:156px;background:#607681;border-radius:8px;color:#fff;font-size:20px}
.ion-migration{position:relative;z-index:1;margin:0 31px;display:grid;gap:16px}
.charge-lane{min-width:0}.charge-direction{display:block;text-align:center;font-size:14px;line-height:1.5;color:#12323b;font-weight:bold;min-height:42px}
.charge-track{height:34px;position:relative;overflow:hidden;background:#ffffffa8;border-radius:8px}
.charge-particle{position:absolute;top:3px;left:calc(50% - 14px);width:28px;height:28px;display:grid;place-items:center;border-radius:50%;font-size:20px;font-weight:800;color:#fff}
.charge-positive{background:#1668b2}.charge-negative{background:#8a467e}
.charge-particle:nth-child(2){left:calc(50% - 42px)}.charge-particle:nth-child(3){left:calc(50% + 14px)}
.electro-divider{position:absolute;top:40px;bottom:12px;left:calc(50% - 3px);width:6px;background:#c5dce5;opacity:.55}
.electro-key{font-size:15px;line-height:1.6;margin:12px 0 0;text-align:center;color:#12323b}
.electro-note{font-size:15px;line-height:1.6;margin:14px 0 0;overflow-wrap:break-word}
.electro-running .charge-negative{animation:ionLeft 3.2s linear infinite;animation-delay:var(--particle-delay)}
.electro-running .charge-positive{animation:ionRight 3.2s linear infinite;animation-delay:var(--particle-delay)}
.electro-running .electron-out i{animation:electronUp 2.2s linear infinite}
.electro-running .electron-in i{animation:electronDown 2.2s linear infinite}
.electro-running .electro-gas{animation:electroGasRise 2.8s ease-in-out infinite;animation-delay:var(--gas-delay)}
@keyframes ionLeft{from{left:calc(100% - 28px)}to{left:0}}
@keyframes ionRight{from{left:0}to{left:calc(100% - 28px)}}
@keyframes electronUp{from{top:56px}to{top:0}}
@keyframes electronDown{from{top:0}to{top:56px}}
@keyframes electroGasRise{0%,100%{transform:translateY(0)}50%{transform:translateY(-7px)}}
@media(max-width:380px){.electron-circuits{gap:6px}.electron-route{flex-direction:column;align-items:flex-start}.electro-side-labels{font-size:14px}.ion-migration{margin-inline:25px}.electro-gas{flex-basis:24px;width:24px;height:24px;font-size:11px}.electro-poles span{width:18px;height:162px}}
@media(prefers-reduced-motion:reduce){.electro-running .charge-particle,.electro-running .electron-route i,.electro-running .electro-gas{animation:none}.electro-running .charge-negative{left:0}.electro-running .charge-positive{left:calc(100% - 28px)}}
#level2 .learning-grid{align-items:start}

/* Begin mixed; sort once, then show gas originating at the electrodes. */
.electro-cell{min-height:330px}
.ion-migration{display:block;height:190px;margin-top:74px;margin-bottom:0}
.charge-lane{position:absolute;inset:0}
.charge-direction{display:none}
.charge-track{height:100%;overflow:visible;background:transparent}
.charge-particle{animation:none;top:10px;left:0;z-index:1}
.charge-negative:nth-child(1){left:0;top:10px}
.charge-negative:nth-child(2){left:calc(50% - 14px);top:70px}
.charge-negative:nth-child(3){left:calc(100% - 28px);top:130px}
.charge-positive:nth-child(1){left:calc(100% - 28px);top:10px}
.charge-positive:nth-child(2){left:0;top:70px}
.charge-positive:nth-child(3){left:calc(50% - 14px);top:130px}
.electro-running .charge-negative{animation:sortNegative 3s ease-in-out forwards;animation-delay:0s}
.electro-running .charge-positive{animation:sortPositive 3s ease-in-out forwards;animation-delay:0s}
@keyframes sortNegative{to{left:0}}
@keyframes sortPositive{to{left:calc(100% - 28px)}}
.electro-poles span{height:220px}
.electro-gases{position:absolute;inset:50px 0 12px;margin:0;gap:0;pointer-events:none;z-index:3}
.electro-gases>div{position:relative;min-width:0}
.electro-gases>div>span{opacity:0;position:absolute;top:0;left:0;right:0}
.electro-gases>div>div{position:absolute;inset:28px 0 0;display:block;min-height:0}
.electro-gas{position:absolute;bottom:2px;left:10px;opacity:0;visibility:hidden;transform:none}
.electro-gas:nth-child(2){left:25px}
.electro-gases>div:last-child .electro-gas{left:auto;right:10px}
.electro-gases>div:last-child .electro-gas:nth-child(even){right:25px}
.electro-running .electro-gas{animation:none}
.electro-gas-phase .electro-gases>div>span{opacity:1}
.electro-gas-phase .electro-gas{visibility:visible;animation:gasFromElectrode 3s linear infinite;animation-delay:var(--gas-delay)}
@keyframes gasFromElectrode{0%{bottom:2px;opacity:0;transform:scale(.55)}12%{opacity:1;transform:scale(1)}85%{opacity:1}100%{bottom:calc(100% - 28px);opacity:0;transform:scale(1)}}
.electro-divider{top:55px}
@media(max-width:380px){.electro-poles span{height:220px}.electro-gas{left:5px}.electro-gas:nth-child(2){left:17px}.electro-gases>div:last-child .electro-gas{right:5px}.electro-gases>div:last-child .electro-gas:nth-child(even){right:17px}}
@media(prefers-reduced-motion:reduce){.electro-running .charge-particle{animation:none}.electro-running .charge-negative{left:0}.electro-running .charge-positive{left:calc(100% - 28px)}.electro-gas-phase .electro-gas{animation:none;opacity:1;bottom:auto;top:5px}.electro-gas-phase .electro-gas:nth-child(2){top:36px}.electro-gas-phase .electro-gas:nth-child(3){top:67px}.electro-gas-phase .electro-gas:nth-child(4){top:98px}}
.charge-positive:nth-child(1){top:40px}.charge-positive:nth-child(2){top:100px}.charge-positive:nth-child(3){top:160px}
.electro-gas{left:0}.electro-gas:nth-child(2){left:8px}.electro-gases>div:last-child .electro-gas{right:0}.electro-gases>div:last-child .electro-gas:nth-child(even){right:8px}

/* Twice the movement speed; stagger the bubbles from the first frame. */
.interaction .h2-bubble{animation-duration:2.2s}
.interaction .h2-bubble:nth-child(1){animation-delay:0s}
.interaction .h2-bubble:nth-child(2){animation-delay:-.44s}
.interaction .h2-bubble:nth-child(3){animation-delay:-.88s}
.interaction .h2-bubble:nth-child(4){animation-delay:-1.32s}
.interaction .h2-bubble:nth-child(5){animation-delay:-1.76s}
.interaction .h2-bubble.caught-h2{animation:none}
.interaction .h2-bubble:nth-child(4),.interaction .h2-bubble:nth-child(5){animation-name:h2DriftInward}@keyframes h2DriftInward{0%,100%{transform:translate(0,0)}50%{transform:translate(-15px,-25px)}}

.bonus-video-panel .bonus-native-video{aspect-ratio:4/3;height:auto;object-fit:contain}