.zsa-th-header {position:relative;margin-bottom:28px;}
.zsa-th-topline {display:flex;align-items:center;justify-content:space-between;flex-wrap:wrap;gap:16px;padding:0 0 20px;border-bottom:1px solid #dde4ed;}
.zsa-th-identity {display:flex;align-items:center;gap:12px;min-width:0;flex:1 1 400px;}
.metals .zsa-th-brand {display:inline-flex;align-items:center;flex-shrink:0;min-height:52px;min-width:52px;text-decoration:none;color:var(--zsa-navy);}
.zsa-th-brand img {display:block;flex-shrink:0;}
.zsa-th-header-tools {display:flex;align-items:center;justify-content:flex-end;flex-wrap:wrap;gap:16px;max-width:100%;margin-left:auto;}
.zsa-th-header-buttons {display:flex;align-items:center;gap:8px;}
.metals .zsa-th-share-toggle {display:inline-flex;align-items:center;justify-content:center;gap:8px;padding:9px 12px;min-height:44px;background:white;}
.zsa-th-icon {width:18px;height:18px;flex-shrink:0;}
.zsa-th-instructions-open {flex-shrink:0;}
.metals h1 {min-width:0;font-size:clamp(1.6rem,1.2rem + 1.2vw,2rem);letter-spacing:-.035em;line-height:1.15;margin:0;font-weight:650;}
.zsa-th-lede {color:var(--zsa-navy);font-size:clamp(1.05rem,1rem + .3vw,1.2rem);font-weight:500;}
.zsa-th-share-panel {margin-top:14px;padding:20px;border:1px solid #cdd9e9;border-radius:12px;background:white;box-shadow:0 7px 20px rgba(11,42,91,.06);}
.zsa-th-share-heading {display:flex;align-items:center;justify-content:space-between;gap:12px;margin-bottom:5px;}
.zsa-th-share-heading h2 {font-size:18px;font-weight:600;}
.metals .zsa-th-icon-button {display:inline-flex;align-items:center;justify-content:center;min-width:44px;min-height:44px;border:1px solid #d5deea;border-radius:8px;background:#f7f9fc;color:#425a7b;font-size:24px;padding:0;line-height:1;}
.metals .zsa-th-fullscreen-toggle {width:46px;min-width:46px;height:46px;min-height:46px;flex-shrink:0;background:white;}
.metals .zsa-th-fullscreen-toggle[hidden] {display:none;}
.zsa-th-fullscreen-toggle[aria-pressed="true"] {background:#edf4ff;border-color:#194d9d;}
.metals .zsa-th-fullscreen-status {margin-top:12px;}
.zsa-th-share-label {display:block;margin:14px 0 6px;font-size:12px;font-weight:600;color:#536075;}
.zsa-th-share-link {display:flex;gap:8px;align-items:stretch;}
.zsa-th-share-link input {display:block;flex:1 1 200px;min-width:0;min-height:46px;width:100%;border:1px solid #b8c8dc;border-radius:8px;padding:9px 11px;background:#f8fafd;color:#334e72;font-size:13px;}
.zsa-th-share-options {display:flex;flex-wrap:wrap;align-items:center;gap:7px;margin-top:12px;}
.zsa-th-share-options a {display:inline-flex;align-items:center;justify-content:center;gap:7px;min-width:44px;min-height:44px;padding:8px 12px;border:1px solid #d8e1ed;border-radius:8px;color:#355579;font-size:13px;text-decoration:none;background:white;}
.zsa-th-share-options a:hover {background:#f0f5fd;}
.zsa-th-share-status {min-height:21px;margin-top:10px!important;font-size:12px;color:#38623e;}
.zsa-th-instructions {width:calc(100% - 32px);max-width:720px;max-height:85vh;overflow:auto;padding:24px;border:1px solid #c5d3e4;border-radius:15px;background:white;color:var(--zsa-slate);box-shadow:0 18px 60px rgba(11,42,91,.2);font-size:15px;line-height:1.6;}
.zsa-th-instructions::backdrop {background:rgba(11,27,51,.45);}
.zsa-th-instructions-heading {display:flex;align-items:flex-start;justify-content:space-between;gap:14px;margin-bottom:14px;}
.zsa-th-instructions-heading h2 {font-size:23px;line-height:1.25;font-weight:600;}
.zsa-th-instructions-heading button {flex-shrink:0;}
.zsa-th-instructions-steps {margin:18px 0;padding-left:23px;}
.zsa-th-instructions-steps li {padding-left:4px;margin:12px 0;}
.zsa-th-instructions-example {padding:15px 17px;border:1px solid #d6e2f2;border-radius:10px;background:#f5f8fd;}
.zsa-th-instructions-example-label {font-size:11px;letter-spacing:.06em;text-transform:uppercase;font-weight:600;color:#536782;}
.zsa-th-instructions-equation {margin:6px 0 13px!important;color:var(--zsa-navy);font-size:22px;line-height:1.5;}
.zsa-th-instructions-equation:last-child {margin-bottom:0!important;}
.zsa-th-instructions-equation sub,.zsa-th-instructions-steps sub {font-size:.7em;line-height:0;vertical-align:-.2em;}
.zsa-th-instructions-equation sup,.zsa-th-instructions-steps sup {font-size:.7em;line-height:0;vertical-align:.4em;}
.zsa-th-instructions-note {margin-top:16px!important;font-size:13px;color:#536075;}

body:has(.metals){background:#edf2f7}.metals{--zsa-max-width:1400px;--zsa-navy:#102d4f;max-width:1400px;padding:28px 36px 32px;background:#f6f8fb;color:#40546b}.metals [hidden]{display:none!important}.metals h1,.metals h2,.metals h3{color:#102d4f}.metals h1{font-size:clamp(1.3rem,1rem + 1vw,1.85rem);line-height:1.2;margin:0;letter-spacing:-.04em}.metals h3{font-size:21px;font-weight:600;margin:0}.metals p{line-height:1.6}.metals .zsa-th-header{margin:0}.metals .zsa-th-topline{padding-bottom:22px;border-color:#dce5ed}.metals .zsa-th-identity{gap:15px;flex-basis:520px}.metals .zsa-th-brand{background:white;border:1px solid #e0e8f0;border-radius:15px;padding:8px;box-shadow:0 3px 10px #102d4f08}.metals .brand-name{font-size:10px;letter-spacing:.18em;margin:0 0 6px;color:#356085}.metals .zsa-th-header-buttons .zsa-btn{font-size:13px;border-radius:9px;background:white;padding:9px 13px;border-color:#cad7e4;color:#274864}.metals .zsa-th-icon{width:18px;height:18px;margin:0}.lab-links{display:flex;justify-content:space-between;align-items:center;gap:16px;padding-top:16px;font-size:12px}.lab-links a{text-decoration:none;color:#526d85;padding:7px 0}.lab-links>span{font-size:9px;letter-spacing:.13em;color:#61778b}.intro{display:flex;justify-content:space-between;align-items:center;gap:20px;padding:24px 0 26px}.intro .zsa-eyebrow{font-size:10px;letter-spacing:.13em;color:#58748a;margin:0 0 8px}.intro h2{font-size:33px;font-weight:600;letter-spacing:-.04em;line-height:1.2;margin:0 0 7px}.intro p:last-child{font-size:14px;margin:0}.metals .zsa-btn{min-height:44px;font-size:13px;border-radius:8px;border-color:#c9d7e5;background:white}.metals .zsa-btn--primary{background:#187566;color:white;border-color:#187566}.metals .zsa-btn--primary:hover{background:#126357}.metals button:disabled{opacity:.5;cursor:not-allowed}.metals button:focus-visible,.metals summary:focus-visible,.metals a:focus-visible,.metals input:focus-visible{outline:3px solid #387ee0;outline-offset:4px}.workspace{display:grid;grid-template-columns:270px minmax(0,1fr);gap:22px;align-items:start}.controls{display:grid;gap:18px}.sample-box,.station-box,.bench-card{background:#fff;border:1px solid #dce5ef;border-radius:14px;box-shadow:0 4px 18px #193d6508}.sample-box,.station-box{padding:21px}.card-label{font-size:9px!important;letter-spacing:.16em;font-weight:700;color:#536c82;margin:0 0 9px;line-height:1.4!important}.samples{display:grid;grid-template-columns:repeat(3,1fr);gap:8px;margin-top:20px}.sample{display:flex;flex-direction:column;align-items:center;gap:5px;border:1px solid #dce5ed;border-radius:9px;background:#f7f9fc;color:#456078;min-height:114px;cursor:pointer;padding:12px 5px}.sample[aria-pressed=true]{border:2px solid #248476;background:#eff8f5;padding:11px 4px;box-shadow:0 0 0 2px #2484760d}.sample strong{font-size:17px;color:#173e5a}.sample>span:last-child{font-size:9px}.chip{display:block;width:35px;height:24px;margin:5px 0 6px;clip-path:polygon(10% 15%,45% 0,95% 30%,85% 85%,40% 100%,0 70%);filter:drop-shadow(0 4px 3px #142d4055)}.chip-a{background:linear-gradient(145deg,#eef7fa,#a9bcc8 40%,#e5f2f9 45%,#738c9e 60%,#c2d1d8)}.chip-b{background:linear-gradient(140deg,#f3d96b,#d4b03b 55%,#a98a29)}.chip-c{background:linear-gradient(155deg,#a6b1c1,#d1d8e1 40%,#526076 45%,#8993a3)}.small{font-size:12px;color:#526b80;line-height:1.65;margin:13px 0 0}.stations{display:grid;gap:8px;margin-top:16px}.stations button{display:flex;align-items:center;gap:12px;min-height:69px;padding:10px;border:1px solid transparent;border-radius:9px;background:#f5f8fb;text-align:left;color:#526d82;cursor:pointer}.stations button[aria-pressed=true]{background:#eaf3f1;border-color:#a6cec5;color:#1e6a5d}.station-number{font-size:11px;border:1px solid #d2dee6;border-radius:6px;padding:8px 6px;background:#fff}.stations strong{display:block;font-size:12px;font-weight:600;color:#214762}.stations small{display:block;font-size:10px;margin-top:5px}.stations button>span:last-child{margin-left:auto;font-size:17px}.bench-note{font-size:11px;color:#61778b;margin:0 4px;display:flex;gap:8px}.bench-note span{color:#258574}.bench-card{padding:23px}.bench-heading{display:flex;align-items:center;justify-content:space-between;gap:10px;margin-bottom:20px}.sample-badge{background:#e9f4ee;border:1px solid #cae3d6;color:#24644e;font-size:10px;font-weight:600;letter-spacing:.08em;padding:7px 10px;border-radius:30px}.scene{position:relative;background:#183448;border:1px solid #274a60;border-radius:12px;overflow:hidden;box-shadow:inset 0 1px 0 #ffffff12}.scene-topline,.scene-bottom{display:flex;justify-content:space-between;gap:10px;padding:14px 18px;color:#b2ccd9;font-size:9px;letter-spacing:.12em;font-weight:600}.scene-topline{background:#213e52}.scene-bottom{background:#122636;border-top:1px solid #395364;font-size:9px;min-height:41px;align-items:center}.scene-bottom span:first-child{color:#b8dccf}.metals #apparatus{display:block;width:100%;height:auto;margin:0}.svg-label{fill:#9bb6c8;font-size:12px;letter-spacing:2px;font-family:Inter,Arial,sans-serif}.interaction{min-height:110px;padding:19px 0 15px}.interaction label{display:flex;justify-content:space-between;gap:10px;font-size:13px;color:#294e69;font-weight:600}.interaction label span{font-size:9px;color:#718496;font-weight:500}.interaction input[type=range]{width:100%;height:26px;accent-color:#187566;margin-top:10px}.interaction button{margin:0 6px 6px 0}.interaction .small{margin:6px 0 0}.observation{border:1px solid #cfe0db;border-left:3px solid #288576;border-radius:9px;background:#eef6f3;padding:14px 17px;min-height:95px}.observation .card-label{color:#387468}.observation>p:last-child{color:#305f55;font-size:13px;margin:0;line-height:1.65}.model-note{margin:22px 0 0;padding:17px 21px;border:1px solid #dce5ed;border-radius:12px;background:#fff;font-size:13px}.model-note summary{cursor:pointer;color:#3d5871;font-weight:550;min-height:27px}.model-note p{margin:14px 0 0}.metals .zsa-footer{display:flex;justify-content:space-between;flex-wrap:wrap;gap:10px;font-size:11px;color:#536b80;margin-top:18px;padding-top:18px;border-color:#dce6ee}.time-track{display:flex;align-items:center;gap:16px;margin-top:14px}.time-track progress{flex:1;width:100%;height:7px;accent-color:#248476}.time-track span{font:14px ui-monospace,monospace;color:#2d6156;white-space:nowrap}.pressing #pestle{animation:press-pestle .65s ease-in-out 3;transform-origin:465px 290px}@keyframes press-pestle{50%{transform:translate(-5px,20px) rotate(-7deg)}}.contacted #probe-left{transform:translate(-21px,5px)}.contacted #probe-right{transform:translate(22px,5px)}#probe-left,#probe-right{transition:transform .5s ease}.pipetting #acid-drop{animation:drip .4s linear 3}@keyframes drip{from{transform:translateY(0);opacity:1}to{transform:translateY(70px);opacity:.2}}.adding-solid #falling-solid{animation:fall-solid 1s ease-in forwards}@keyframes fall-solid{to{transform:translate(406px,338px) scale(.18)}}.disposing #tube{transform-origin:406px 250px;animation:pour 1.7s ease-in-out}@keyframes pour{30%,70%{transform:translate(110px,-90px) rotate(63deg)}}.bubble{fill:#d5f3fc;fill-opacity:.16;stroke:#c7f2ff;stroke-opacity:.7;stroke-width:1}.metals .zsa-th-share-panel h2{font-size:21px;margin:0}.metals .zsa-th-share-panel p{font-size:13px}.metals .zsa-th-instructions h2{margin:0;font-size:24px}.metals .zsa-th-instructions p,.metals .zsa-th-instructions li{font-size:15px;line-height:1.7}.metals .zsa-th-share-url{min-width:0}@media(min-width:1450px){.metals{margin:24px auto;border:1px solid #dee7ef;border-radius:20px}}@media(max-width:1000px){.metals{padding:22px}.workspace{grid-template-columns:225px minmax(0,1fr);gap:16px}.sample-box,.station-box{padding:16px}.bench-card{padding:18px}.scene-topline,.scene-bottom{font-size:8px;padding:12px}.intro h2{font-size:29px}}@media(max-width:760px){.metals{padding:18px 14px}.metals .zsa-th-identity{flex-basis:100%}.metals .zsa-th-header-tools{margin-left:0}.metals h1{font-size:22px}.metals .zsa-th-brand img{width:40px;height:auto}.metals .zsa-th-identity{gap:11px}.intro{padding:22px 0;align-items:start}.intro h2{font-size:27px}.intro p:last-child{font-size:12px}.intro>button{font-size:11px;padding:8px;white-space:nowrap}.workspace{grid-template-columns:1fr}.controls{grid-template-columns:1fr;gap:12px}.sample-box{padding:15px}.sample-box h3{font-size:17px}.samples{margin-top:12px}.sample{min-height:82px;display:grid;grid-template-columns:1fr 1fr;gap:0;padding:9px}.sample[aria-pressed=true]{padding:8px}.sample .chip{grid-row:span 2;width:36px;margin:0 auto}.sample>span:last-child{font-size:9px}.sample-box .small{margin:10px 0 0}.station-box{padding:13px}.stations{grid-template-columns:repeat(2,1fr);gap:7px;margin-top:12px}.stations button{min-height:61px;gap:9px;padding:8px}.stations strong{font-size:11px}.stations small{font-size:9px}.station-number{padding:7px 5px}.bench-note{display:none}.bench-card{padding:15px}.bench-heading{margin-bottom:15px}.scene-topline{font-size:7px;padding:11px 10px;letter-spacing:.05em}.scene-topline>span:last-child{display:none}.scene-bottom{font-size:7px;padding:10px;letter-spacing:.04em}.scene svg text.svg-label{font-size:15px;letter-spacing:1px}.interaction label{font-size:12px}.metals .zsa-th-share-link{flex-wrap:wrap}.lab-links>span{font-size:7px}.metals .zsa-footer{font-size:10px}.observation{min-height:105px}.metals #apparatus{min-height:200px}.interaction .small{font-size:11px}.model-note{font-size:12px}}@media(prefers-reduced-motion:reduce){.metals *, .metals *::before,.metals *::after{animation:none!important;transition:none!important}}@media print{.zsa-th-header-tools,.lab-links,.controls,.interaction,dialog{display:none!important}.workspace{grid-template-columns:1fr}.metals{background:white}.scene{print-color-adjust:exact;-webkit-print-color-adjust:exact}}
#probes{transform:translateY(-45px);transition:transform .5s ease}.contacted #probes{transform:translateY(0)}
.lab-links>span,.bench-note,.interaction label span{color:#52677d}

/* Compact title header; the simulation begins directly beneath it. */
.metals .zsa-th-header{margin-bottom:24px}.metals .zsa-th-identity{gap:12px}.metals .zsa-th-brand{min-width:44px;min-height:44px;width:44px;height:44px;padding:5px;border-radius:11px}.metals .zsa-th-brand img{width:34px;height:auto}

.atwood .intro{padding:26px 0}.atwood .intro h2{font-size:30px}.eyebrow{font-size:10px;letter-spacing:.14em;color:#536f83}.ideal{white-space:nowrap;color:#217966;background:#e4f2ec;border:1px solid #bddcd0;border-radius:24px;padding:9px 12px;font-size:10px;letter-spacing:.08em}.control-card{padding:22px;background:white;border:1px solid #dce5ef;border-radius:14px}.atwood .control-card h3{font-size:20px}.control-card label:not(.check){display:flex;justify-content:space-between;gap:8px;font-size:13px;font-weight:600;margin:24px 0 8px;color:#244962}.control-card output{color:#187566;font-variant-numeric:tabular-nums}.control-card input[type=range]{width:100%;accent-color:#187566;min-height:28px}.control-card .wide{width:100%;margin-top:18px}.presets{display:grid;gap:8px;margin-top:8px}.check{display:flex;align-items:center;gap:8px;font-size:12px;min-height:44px}.check input{accent-color:#187566;width:17px;height:17px}.control-card select{width:100%;min-height:44px;padding:8px;border:1px solid #b9cad8;border-radius:8px;color:#294e69;background:#fff}.back{font-size:12px;color:#526d85;text-decoration:none;margin:0 6px}.run-controls{display:flex;gap:10px;align-items:center;flex-wrap:wrap;padding:18px 0}.run-controls>span{font-size:12px;flex:1 1 150px}.readouts{display:grid;grid-template-columns:repeat(4,1fr);gap:1px;border:1px solid #dce5ed;border-radius:10px;overflow:hidden;background:#dce5ed}.readouts>div{background:#f5f8fb;padding:16px 12px}.readouts span{display:block;font-size:8px;letter-spacing:.1em;color:#536d82;margin-bottom:8px}.readouts strong{font-size:20px;color:#173e5a;font-weight:600;font-variant-numeric:tabular-nums}.readouts small{font-size:11px;font-weight:400}.explanation{margin-top:18px;background:#eef6f3;border-left:3px solid #288576;border-radius:8px;padding:16px 18px}.explanation p{font-size:13px;margin:6px 0;color:#305f55}.atwood .workspace{grid-template-columns:280px minmax(0,1fr)}.atwood #apparatus{max-height:570px}.atwood button{cursor:pointer}.atwood .intro p:last-child{max-width:680px}.atwood .scene-topline{font-size:8px}.atwood .zsa-th-identity{flex-basis:360px}@media(max-width:1000px){.atwood .workspace{grid-template-columns:230px minmax(0,1fr)}.atwood .readouts{grid-template-columns:repeat(2,1fr)}.ideal{display:none}}@media(max-width:760px){.atwood .workspace{display:flex;flex-direction:column}.atwood .controls{width:100%;grid-template-columns:1fr 1fr;gap:12px}.atwood .control-card{padding:16px}.atwood .bench-card{width:100%;padding:14px}.atwood .intro h2{font-size:25px}.atwood .control-card label:not(.check){margin-top:16px}.atwood .back{grid-column:1/-1}.atwood .bench-heading h3{font-size:18px}.atwood .sample-badge{font-size:8px}}@media(max-width:430px){.atwood .controls{grid-template-columns:1fr}.atwood .intro{padding:20px 0}.atwood .scene-topline span:last-child{display:none}.atwood .bench-heading{flex-wrap:wrap}}
/* Keep the apparatus directly below the activity header. */
.atwood .workspace{margin-top:24px}