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.pt-gallery-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:24px}.pt-app .pt-gallery-item{padding:0;overflow:hidden;text-align:left;border:1px solid #bdcebf;background:#f0f4eb;display:block}.pt-gallery-item img{display:block;width:100%;height:auto;aspect-ratio:1.5;object-fit:cover;background:#142a2d}.pt-gallery-item>span{display:grid;grid-template-columns:44px 1fr;gap:2px 9px;padding:16px}.pt-gallery-item b{grid-row:1/3;font-family:Georgia,serif;font-size:30px;line-height:1.2}.pt-gallery-item strong{font-size:16px;font-weight:600}.pt-gallery-item small{font-size:11px;color:#536c5b}.pt-gallery-item:hover strong{text-decoration:underline;text-underline-offset:3px}
@media(max-width:1000px){.pt-gallery-grid{grid-template-columns:repeat(3,minmax(0,1fr));gap:17px}}
@media(max-width:720px){.pt-gallery-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}.pt-gallery-item>span{padding:12px;display:block}.pt-gallery-item b{font-size:27px;display:block;margin-bottom:5px}.pt-gallery-item strong{font-size:14px;display:block;overflow-wrap:anywhere}.pt-gallery-item small{font-size:10px;line-height:1.4;display:block;margin-top:5px}.pt-specimen-note{font-size:11px}}
@media(min-width:1550px){.pt-periodic-grid{grid-template-rows:24px repeat(7,62px) 10px repeat(2,62px)}}
@media(max-width:1200px){.pt-heading{align-items:start}.pt-course-controls{max-width:340px;gap:10px}.pt-course-controls .pt-quiet{max-width:none}.pt-table-layout{grid-template-columns:minmax(0,1fr) 265px;gap:20px}.pt-periodic-grid{min-width:630px;gap:3px}.pt-inspector-body{padding:17px}.pt-app .pt-tabs>button{padding:12px 13px}.pt-trend-layout{grid-template-columns:minmax(0,1fr) minmax(260px,.9fr);gap:20px}.pt-big-value{font-size:25px}.pt-graph-panel{padding:16px}.pt-model-layout{gap:20px}}
@media(max-width:1000px){.pt-heading{display:block}.pt-course-controls{max-width:none;margin-top:22px;align-items:end}.pt-table-layout{grid-template-columns:minmax(0,1fr)}.pt-inspector{display:grid;grid-template-columns:230px 1fr}.pt-inspector-body{padding:24px}.pt-inspector:not(:has(.pt-specimen)){display:block}.pt-specimen{height:100%;aspect-ratio:auto;min-height:260px}.pt-definition-grid{grid-template-columns:repeat(4,1fr)}.pt-inspector-actions{flex-direction:row;align-items:center;flex-wrap:wrap}.pt-periodic-grid{min-width:650px}.pt-tabs{gap:0}.pt-tab-actions{margin-left:0}.pt-trend-layout{grid-template-columns:1fr}.pt-investigation-layout{grid-template-columns:210px 1fr;gap:22px}.pt-lesson-nav{padding-right:15px}.pt-model-layout{grid-template-columns:1fr 1fr}}
@media(max-width:720px){.pt-masthead{padding:16px 19px;gap:12px;align-items:start}.pt-brand{font-size:18px}.pt-brand-mark{width:34px;height:39px;font-size:23px}.pt-brand-sub{font-size:10px}.pt-masthead nav{gap:10px;font-size:12px;flex-wrap:wrap;justify-content:end;max-width:160px}.pt-app .pt-masthead button{padding:6px 9px;min-height:32px;font-size:12px}.pt-heading{padding:25px 20px 22px}.pt-heading p{font-size:14px;max-width:360px}.pt-course-controls{gap:13px;row-gap:8px;margin-top:19px}.pt-course-controls label{font-size:12px}.pt-course-controls select{min-width:160px}.pt-course-controls .pt-quiet{margin-left:auto;font-size:12px}.pt-tabs{margin:0 20px;gap:0}.pt-app .pt-tabs>button{font-size:13px;padding:12px 9px;min-height:46px}.pt-tab-actions{width:100%;justify-content:end;border-top:1px solid #e0e6dc}.pt-app .pt-tab-actions button{font-size:12px;min-height:34px;padding:5px 9px}.pt-workspace{padding:20px}.pt-table-toolbar{gap:11px;display:grid;grid-template-columns:1fr 1fr}.pt-search-label{grid-column:1/-1;max-width:none}.pt-table-toolbar label:nth-child(2){margin:0;grid-column:1/-1}.pt-table-toolbar select{width:100%;min-width:0}.pt-overview-head{font-size:11px}.pt-overview-head p{max-width:200px}.pt-periodic-grid{min-width:0;grid-template-rows:15px repeat(7,24px) 7px repeat(2,24px);gap:2px;pointer-events:none}.pt-app .pt-tile{min-height:0;padding:1px;border-radius:1px;border-color:#9eb5a7}.pt-tile .pt-symbol{font-size:10px;font-weight:600}.pt-tile .pt-z,.pt-tile .pt-weight{display:none}.pt-group-number{font-size:8px}.pt-range-placeholder{font-size:6px;line-height:1.1}.pt-row-label{font-size:7px;padding:0}.pt-table-empty-inner{font-size:12px;max-width:170px}.pt-table-empty-inner span{display:none}.pt-legend{font-size:11px;gap:10px;margin-top:10px}.pt-legend i{width:11px;height:11px}.pt-mobile-selection{display:block;margin-top:20px}.pt-mobile-selection p{font-size:12px;color:var(--muted);margin-top:7px}.pt-element-list{display:flex;gap:7px;flex-wrap:wrap;max-height:220px;overflow:auto;padding:3px}.pt-app .pt-list-element{display:flex;align-items:center;gap:8px;min-height:44px;padding:8px 11px;font-size:13px}.pt-list-element b{font-size:18px}.pt-list-element[aria-pressed=true]{background:#d6e8d1;border-color:#34694a}.pt-list-count{flex-basis:100%;font-size:12px;color:var(--muted);margin:5px 0}.pt-table-foot{font-size:11px;display:block}.pt-table-foot button{margin-top:8px;min-height:32px}.pt-inspector{display:block!important;margin-top:2px}.pt-specimen{aspect-ratio:2.2;max-height:215px;min-height:0}.pt-inspector-body{padding:22px}.pt-definition-grid{grid-template-columns:1fr 1fr}.pt-inspector-actions{flex-direction:column;align-items:stretch}.pt-element-heading{gap:22px}.pt-element-symbol{font-size:64px}.pt-table-scroll.pt-enlarged{border:1px solid var(--line);border-radius:4px;max-height:550px;overflow:auto;padding:9px}.pt-enlarged .pt-periodic-grid{min-width:900px;grid-template-rows:22px repeat(7,53px) 10px repeat(2,53px);gap:4px;pointer-events:auto}.pt-enlarged .pt-tile .pt-symbol{font-size:24px}.pt-enlarged .pt-tile .pt-z{display:block;font-size:9px}.pt-enlarged .pt-tile .pt-weight{display:block;font-size:8px}.pt-enlarged .pt-group-number{font-size:11px}.pt-enlarged .pt-row-label{font-size:10px}.pt-enlarged .pt-table-empty-inner{font-size:18px;max-width:300px}.pt-enlarged .pt-table-empty-inner span{display:block}.pt-section-heading{display:block;margin-bottom:21px}.pt-section-heading h2{font-size:26px}.pt-section-heading p{font-size:14px}.pt-presets{margin-top:15px}.pt-trend-toolbar{display:grid;grid-template-columns:1fr 1fr;gap:12px}.pt-trend-toolbar label:first-child{grid-column:1/-1}.pt-trend-toolbar label select{max-width:none;width:100%;font-size:14px}.pt-trend-toolbar .pt-checkbox{grid-column:1/-1;margin:0;min-height:30px}.pt-graph-panel{padding:15px 11px}.pt-graph-panel h3{font-size:18px}.pt-graph-panel svg text{font-size:13px}.pt-compare-grid{gap:18px}.pt-compare-item h3{font-size:22px}.pt-big-value{font-size:29px}.pt-next-links{align-items:start;gap:13px;flex-direction:column}.pt-next-links p{flex-basis:auto}.pt-investigation-layout{display:block}.pt-lesson-nav{border-right:0;padding:0;margin-bottom:22px}.pt-lesson-nav h2{font-size:21px;margin-bottom:7px}.pt-lesson-nav>p{display:none}.pt-lesson-nav #pt-lessons{max-height:190px;overflow-y:auto;border:1px solid var(--line);border-radius:4px;padding:7px}.pt-lesson-group{margin:9px 10px 5px}.pt-app .pt-lesson-link{font-size:13px;padding:9px 10px}.pt-lesson-link span{font-size:10px}.pt-lesson h2{font-size:27px}.pt-scope-line{font-size:12px}.pt-stepper{margin:14px 0 22px}.pt-stepper li{font-size:11px;padding:8px 0}.pt-stepper b{display:block;margin-bottom:4px}.pt-question{font-size:20px}.pt-evidence{padding:16px}.pt-evidence-text{font-size:15px}.pt-equations{font-size:17px;padding:12px;line-height:1.8}.pt-lesson-actions{gap:8px}.pt-lesson-actions button{font-size:14px}.pt-beakers{gap:9px}.pt-beaker-item{min-width:75px;flex:1}.pt-beaker{width:63px;height:100px}.pt-metal{left:22px;width:18px}.pt-beaker-item small{font-size:10px}.pt-beaker-item strong{font-size:13px}.pt-displacement-grid{grid-template-columns:55px repeat(3,minmax(0,1fr));gap:4px}.pt-app .pt-grid-cell{min-height:65px;padding:5px 3px;font-size:12px}.pt-grid-label{font-size:10px}.pt-grid-cell span{font-size:9px}.pt-observation{gap:12px;padding:12px}.pt-observation p{font-size:13px}.pt-structure-strip{grid-template-columns:repeat(2,1fr);gap:18px}.pt-solubility{grid-template-columns:65px repeat(4,1fr);gap:4px;font-size:11px}.pt-sol-dot{font-size:9px;padding:4px;line-height:1.2}.pt-complex-toolbar{gap:7px}.pt-complex-toolbar label{width:100%;margin:0}.pt-complex-toolbar select{width:100%;font-size:14px}.pt-complex-toolbar button{font-size:12px;padding:8px 11px}.pt-model-layout{grid-template-columns:1fr}.pt-model-stage{margin:0 -3px}.pt-model-stage>p{font-size:11px}.pt-depth-photo{float:none;width:100%;max-height:220px;margin:0 0 20px;aspect-ratio:2}.pt-depth-article h3{font-size:23px}.pt-depth-article p{font-size:15px}.pt-footer{padding:19px 20px;gap:9px 15px;font-size:11px}.pt-footer>span:first-child{width:100%}.pt-footer button{font-size:11px;min-height:32px;padding:0}.pt-notice{margin:0 20px 18px;font-size:13px}.pt-dialog{padding:23px;max-width:calc(100vw - 24px)}.pt-dialog h2{font-size:24px}.pt-present .pt-heading{padding:18px 20px}.pt-present .pt-lesson h2{font-size:28px}.pt-present .pt-question{font-size:22px}.pt-present .pt-evidence-text{font-size:17px}}
.pt-gallery-controls{display:flex;align-items:end;gap:18px;margin-bottom:14px}.pt-gallery-controls>label:first-child{flex:1;max-width:420px}.pt-gallery-controls select{min-width:230px}.pt-scope-line .pt-text-button{font-size:11px;min-height:32px;padding:3px 8px;vertical-align:middle}.pt-compare-facts{margin:17px 0;font-size:13px}.pt-compare-facts dt{font-size:11px;color:#5b7060}.pt-compare-facts dd{margin:0 0 10px}.pt-inspect-selected{display:none!important}.pt-app[data-host=models] .pt-tabs{position:sticky;top:0;z-index:20;background:#fffefa}.pt-inspector,.pt-lesson,.pt-table-view{scroll-margin-top:100px}
.pt-narrow-label,.pt-phone-lesson-label,.pt-mobile-table-back{display:none!important}.pt-table-filters{margin:0!important;flex:1;min-width:0}.pt-table-filters>summary{display:none}.pt-filter-controls{display:flex;gap:17px;justify-content:end;align-items:end}.pt-filter-controls>label{margin-left:0!important}
@media(max-width:720px){.pt-wide-label{display:none!important}.pt-narrow-label{display:inline!important}.pt-masthead{gap:10px;padding-top:13px;padding-bottom:13px}.pt-brand{font-size:16px;flex-shrink:0}.pt-brand-sub{font-size:9px}.pt-masthead nav{max-width:125px;font-size:10px;gap:7px}.pt-masthead nav a{white-space:nowrap}.pt-heading{padding-top:20px;padding-bottom:16px}.pt-course-controls{display:grid;grid-template-columns:minmax(0,1fr) auto 27px;gap:9px;align-items:end}.pt-course-controls select{width:100%;min-width:0;font-size:13px}.pt-course-controls .pt-switch{font-size:12px;gap:6px}.pt-course-controls .pt-quiet{width:27px;min-height:44px;max-width:27px;margin:0;padding:0;font-size:19px;text-decoration:none}.pt-switch-track{width:34px;height:23px}.pt-switch input:checked+.pt-switch-track:after{left:13px}.pt-app .pt-tabs>button{padding:11px 8px;font-size:12px;min-height:43px}.pt-tab-actions{width:auto;border:0;margin-left:auto}.pt-table-toolbar{display:block}.pt-search-label{margin-bottom:11px}.pt-table-filters{width:100%}.pt-table-filters>summary{display:block;background:#eef3e9;border:1px solid #c6d5c0;padding:9px 12px;border-radius:4px;min-height:44px;font-weight:400;font-size:13px}.pt-table-filters>summary:after{content:" +";float:right}.pt-table-filters[open]>summary:after{content:" −"}.pt-filter-controls{display:grid;grid-template-columns:1fr 1fr;gap:10px;margin-top:12px}.pt-filter-controls>label:first-child{grid-column:1/-1}.pt-phone-lesson-label{display:flex!important;margin-bottom:8px}.pt-lesson-nav h2,.pt-lesson-nav #pt-lessons{display:none}.pt-lesson-nav{margin-bottom:20px}.pt-phone-lesson-label select{width:100%;font-size:14px}.pt-app .pt-mobile-table-back{display:block!important;min-height:34px;padding:5px 0;border:0;background:transparent;font-size:12px;text-decoration:underline;margin-bottom:17px}.pt-mobile-selection p{margin-bottom:7px}.pt-element-list{max-height:150px}}
@media(max-width:720px){.pt-app .pt-inspect-selected{display:block!important;min-height:44px;max-width:210px;font-size:12px;padding:7px 9px;text-align:left}.pt-overview-head #pt-table-message{display:none}.pt-app:not([data-current-view=table]) .pt-heading>div>p{display:none}.pt-app:not([data-current-view=table]) .pt-heading{padding-bottom:15px}.pt-app:not([data-current-view=table]) .pt-course-controls{margin-top:14px}.pt-app .pt-tabs{scroll-margin-top:0}}
@media(max-width:720px){.pt-gallery-controls{display:block}.pt-gallery-controls>label{margin-bottom:12px}.pt-gallery-controls select{min-width:0;width:100%}.pt-scope-line .pt-text-button{font-size:11px}}
#pt-graph{overflow-x:auto;max-width:100%;scrollbar-width:thin}.pt-graph-select-label{margin-top:15px;max-width:340px}.pt-graph-button:focus{outline:none}.pt-graph-button:focus .pt-point{stroke:#ad630b;stroke-width:4}.pt-orbital-set{display:flex;gap:4px;flex-wrap:nowrap}.pt-orbital{flex-shrink:0}.pt-app .pt-scope-line button{white-space:nowrap}
@media(max-width:720px){.pt-orbital-set{gap:3px}.pt-orbital{min-width:22px;height:28px;font-size:18px}.pt-box-row{gap:3px}.pt-orbital-label{margin-right:0}}
@media(prefers-reduced-motion:reduce){.pt-app *{animation:none!important;transition:none!important;scroll-behavior:auto!important}}
@media print{body>*:not(.pt-app):not(:has(.pt-app)){display:none!important}.pt-app{max-width:none!important;font-size:11pt;background:white!important;color:#111!important}.pt-masthead,.pt-heading p,.pt-course-controls,.pt-tabs,.pt-table-toolbar,.pt-search-results,.pt-lesson-nav,.pt-lesson-actions,.pt-next-links,.pt-complex-toolbar,.pt-footer button,.pt-dialog,.pt-toast,.pt-mobile-selection,.pt-element-list,.pt-overview-head button{display:none!important}.pt-heading{padding:0 0 15px}.pt-heading h1{font-size:22pt}.pt-workspace{padding:0}.pt-table-layout,.pt-trend-layout,.pt-model-layout{display:block}.pt-inspector{margin-top:20px;break-inside:avoid}.pt-specimen{max-width:220px;float:right}.pt-table-scroll{overflow:visible}.pt-periodic-grid{min-width:0;grid-template-rows:17px repeat(7,36px) 8px repeat(2,36px);gap:3px;print-color-adjust:exact;-webkit-print-color-adjust:exact}.pt-app .pt-tile{min-height:0}.pt-tile .pt-symbol{font-size:16px}.pt-tile .pt-z{font-size:8px}.pt-tile .pt-weight{font-size:7px}.pt-graph-panel{break-inside:avoid}.pt-comparison{margin-top:18px}.pt-stepper{margin-top:8px}.pt-evidence,.pt-observation,.pt-equations{break-inside:avoid;print-color-adjust:exact}.pt-choices{display:block}.pt-choice{display:block;width:100%;margin:6px 0;break-inside:avoid}.pt-model-stage{max-width:600px}.pt-lesson h2{font-size:20pt}.pt-footer{padding:14px 0;font-size:9pt}.pt-present{position:static!important;overflow:visible!important}.pt-app a{color:#111}.pt-lesson-actions button{display:none}.pt-row-label{font-size:8px}}