.topic-symbol{width:72px;min-width:72px;height:69px;padding:10px;display:flex;flex-direction:column;align-items:flex-start;justify-content:center;overflow:hidden}
.topic-symbol small{font-size:10px;white-space:nowrap;margin:0 0 7px;letter-spacing:0;flex:none}
.equation-stage.has-equation-action{position:relative;padding-bottom:84px;min-height:220px}.equation-actions{position:absolute;right:18px;bottom:16px;display:flex;justify-content:flex-end;max-width:calc(100% - 36px)}.equation-actions .btn{min-width:150px;min-height:44px;font-size:14px;white-space:nowrap}.practice-wrap .keyboard-top .editor-tools,.demo-card .keyboard-top .editor-tools{margin-left:auto}.demo-card .equation-stage.has-equation-action{padding-bottom:84px}.demo-card .practice-actions{margin-top:0;padding-top:16px}
@media(max-width:700px){.equation-stage.has-equation-action{padding-bottom:80px;min-height:230px}.equation-actions{right:14px;bottom:14px;max-width:calc(100% - 28px)}.equation-actions .btn{min-width:138px;font-size:14px;padding:11px 16px}.demo-card .equation-stage.has-equation-action{padding-bottom:80px}}
.topic-symbol>span{display:block;width:100%;font-size:24px;white-space:nowrap;line-height:1.3;letter-spacing:-.5px}
.topic-copy{min-width:0}.topic-copy h3{overflow-wrap:break-word}
.utility-nav{display:grid;gap:3px}.utility-nav .nav-link{width:100%}.sidebar>.utility-nav{display:none}
.equation-stage{display:grid;grid-template-columns:minmax(0,1fr) minmax(65px,125px) minmax(0,1fr);align-items:center;gap:14px;padding:26px 22px 18px;min-height:218px}
.equation-side{width:100%;max-width:100%;min-width:0;flex:none;align-self:center;overflow:hidden;gap:8px}
.known-term{max-width:100%;overflow-x:auto;overflow-y:hidden;flex-shrink:1;line-height:1.5}
.known-formula{white-space:nowrap}.known-term:has(.practice-structure){display:flex;flex-direction:column;align-items:center;min-width:0;flex-basis:100%;font-size:22px}
.known-term:has(.practice-structure) .coefficient{align-self:flex-start}
.formula-editor{box-sizing:border-box;max-width:100%;min-width:0;width:100%;overflow-x:auto;overflow-y:hidden;scrollbar-width:thin}
.formula-editor .formula-token{max-width:none}.equation-hint{grid-column:1/-1;position:static!important;margin:12px 0 0!important;text-align:center;line-height:1.5}
.reaction-arrow{width:100%;min-width:0;max-width:125px;justify-self:center;gap:6px}
.reaction-conditions{position:static!important;transform:none!important;max-width:100%;width:auto;white-space:normal;overflow-wrap:anywhere;line-height:1.5}
.exercise-heading{gap:12px;flex-wrap:wrap}.exercise-mode{margin-left:auto}.structure-toggle{font-size:12px;display:inline-flex;align-items:center;gap:7px;color:var(--muted);white-space:nowrap}.structure-toggle input{accent-color:var(--blue);width:15px;height:15px}
.preview-label{font-size:11px;color:var(--muted);margin:0 0 4px}.answer-structure-list{display:flex;flex-wrap:wrap;gap:12px}.answer-structure-list figure{margin:0;max-width:220px;flex:1 1 160px}.answer-structure-list figcaption{font-size:12px;text-align:center}.answer-structure-list .molecule-graphic{height:120px}.input-structures:empty{display:none}.input-structures{margin:0 0 12px}
.bank-filters{display:flex;overflow-x:auto;width:fit-content;max-width:100%}.bank-note,.bank-count{font-size:12px;color:var(--muted);line-height:1.6}.bank-note{max-width:750px}.bank-count{margin:24px 0 20px}.bank-topic{margin:0 0 32px;content-visibility:auto;contain-intrinsic-size:auto 650px;scroll-margin-top:20px}.bank-topic-heading{display:flex;align-items:center;justify-content:space-between;gap:16px;margin:0 0 12px}.bank-topic-heading h2{font-size:19px;line-height:1.4;margin:4px 0}.bank-topic-heading .muted{font-size:11px;color:var(--muted)}.bank-topic-heading .text-link{white-space:nowrap;font-size:12px}.bank-rows{list-style:none;margin:0;padding:0;background:var(--surface);border:1px solid var(--line);border-radius:16px;overflow:hidden}.bank-row{display:flex;align-items:center;gap:14px;padding:20px 24px;border-bottom:1px solid var(--line)}.bank-row:last-child{border-bottom:0}.bank-row-main{min-width:0;flex:1}.bank-equation{display:flex;align-items:center;flex-wrap:wrap;gap:8px 12px;line-height:1.7;font-size:20px}.bank-side{display:flex;align-items:center;flex-wrap:wrap;gap:6px 9px;min-width:0;max-width:100%}.bank-term{display:inline-block;max-width:100%;white-space:nowrap;overflow-x:auto;overflow-y:hidden;vertical-align:middle;scrollbar-width:thin}.bank-plus,.bank-arrow{color:var(--muted)}.bank-conditions{font-size:12px;color:var(--blue);line-height:1.6;margin:7px 0 0;overflow-wrap:anywhere}.bank-conditions:empty{display:none}.bank-name{font-size:12px;color:var(--muted);margin:6px 0 0;line-height:1.5}.structure-link{flex:none;color:var(--blue)}
.practice-labs{grid-template-columns:repeat(auto-fit,minmax(min(100%,270px),1fr))}.structure-lab-visual{height:150px;display:flex;align-items:center;justify-content:center;background:var(--blue-wash);border-radius:12px;margin:0 0 22px}.structure-lab-visual .molecule-graphic{height:145px;max-width:240px}
.structure-workspace{display:grid;grid-template-columns:235px minmax(0,1fr);gap:20px;margin-top:28px;align-items:start}.molecule-picker{display:grid;gap:6px}.molecule-option{display:flex;flex-direction:column;align-items:flex-start;gap:5px;padding:12px 14px;border:1px solid transparent;border-radius:11px;color:var(--ink);background:transparent;text-align:left;font:inherit;font-size:13px;cursor:pointer}.molecule-option small{color:var(--muted);font-size:11px}.molecule-option:hover{background:var(--surface)}.molecule-option.active{background:var(--surface);border-color:var(--blue);color:var(--blue)}.structure-view{border:1px solid var(--line);border-radius:18px;background:var(--surface);overflow:hidden;min-width:0}.structure-display{min-height:370px;padding:18px;display:flex;align-items:center;justify-content:center}.molecule-graphic{display:flex;align-items:center;justify-content:center;width:100%;max-width:100%;height:165px;min-width:0;overflow:hidden}.molecule-graphic svg{display:block;width:100%;height:100%;max-width:100%}.large-structure{height:340px}.structure-fallback{color:var(--muted);font-size:13px}.structure-caption{padding:22px 26px;border-top:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;gap:14px}.structure-caption h2{font-size:18px;margin:0 0 8px;line-height:1.5}.structure-caption p{margin:0;font-size:16px;color:var(--muted)}.structure-caption .text-link{font-size:12px;white-space:nowrap}.structure-note{max-width:850px;font-size:13px;color:var(--muted);line-height:1.8;margin-top:24px}.structure-dialog-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(min(100%,200px),1fr));gap:18px;margin:20px 0 26px}.structure-dialog-grid figure{margin:0;min-width:0;padding:12px;border:1px solid var(--line);border-radius:12px}.structure-dialog-grid figcaption{display:flex;flex-direction:column;gap:8px;text-align:center;font-size:13px}.structure-dialog-grid figcaption span{overflow-x:auto;white-space:nowrap}.structure-dialog-grid strong{font-weight:500;line-height:1.5}dialog:has(.structure-dialog){width:min(820px,calc(100% - 32px));max-width:none}
.learn-content{max-width:1100px}.demo-card{border:1px solid var(--line);border-radius:20px;background:var(--surface);padding:28px;margin-top:26px}.demo-card .equation-stage{background:var(--bg);border-radius:14px}.demo-card .keyboard{padding:18px 0 0}.demo-card .practice-actions{margin-top:26px}.demo-card .key-row{scroll-margin-top:50px}.learn-bottom{display:flex;align-items:center;justify-content:space-between;gap:25px;margin:22px 0}.learn-bottom p{font-size:12px;line-height:1.8;color:var(--muted);max-width:630px}.learn-bottom a{white-space:nowrap;font-size:13px}
.driver-popover.reactor-tour{font-family:Onest,sans-serif;background:var(--surface);color:var(--ink);border:1px solid var(--line);border-radius:16px;padding:22px;box-shadow:0 16px 60px #001a3929;max-width:340px;min-width:230px}.reactor-tour .driver-popover-title{font-size:18px;font-weight:600;line-height:1.45;margin:0 12px 10px 0}.reactor-tour .driver-popover-description{font:400 13px/1.8 Onest,sans-serif;color:var(--muted)}.reactor-tour .driver-popover-footer{margin-top:20px}.reactor-tour .driver-popover-progress-text{font-size:11px;color:var(--muted);white-space:nowrap}.reactor-tour .driver-popover-navigation-btns{gap:6px}.reactor-tour .driver-popover-footer button{font:500 12px Onest,sans-serif;text-shadow:none;padding:9px 12px;border:0;border-radius:8px;background:var(--bg);color:var(--ink)}.reactor-tour .driver-popover-footer .driver-popover-next-btn{background:var(--blue);color:white}.reactor-tour .driver-popover-close-btn{color:var(--muted)}.reactor-tour .driver-popover-arrow{border-color:transparent}.driver-active-element{border-radius:10px}
.sidebar{overflow-y:auto}.sidebar>.utility-nav{flex-shrink:0}
.molecule-picker{max-height:485px;overflow-y:auto;padding-right:5px;scrollbar-width:thin}
.bank-filters{flex-wrap:wrap}.bank-filters .tab{flex:none}
.welcome-intro{margin:0 0 32px}.welcome-intro h1{margin-bottom:23px;max-width:850px}.welcome-copy{max-width:800px}.welcome-copy p{font-size:15px;line-height:1.85;color:var(--muted);margin:0 0 18px}.welcome-intro>.btn{margin-top:6px;max-width:100%;text-align:left}.welcome-intro>.btn svg{flex:none}
@media(max-width:700px){.welcome-intro{margin-bottom:27px}.welcome-intro h1{margin-bottom:20px;font-size:28px;line-height:1.3}.welcome-copy p{font-size:14px;line-height:1.85;margin-bottom:17px}.welcome-intro>.btn{font-size:14px;padding:12px 16px;gap:8px;margin-top:5px}}
/* Bank controls form one responsive panel; results retain the topic grouping. */
.bank-filter-panel{padding:26px;background:var(--surface);border:1px solid var(--line);border-radius:18px;margin-bottom:25px;min-width:0}.bank-search-line{display:grid;grid-template-columns:minmax(130px,auto) minmax(0,1fr);align-items:center;gap:25px;margin-bottom:22px}.bank-search-label{font-size:15px;font-weight:550}.bank-search-line .search-wrap{max-width:none;margin:0}.bank-search-line .search{font-size:15px;min-height:48px}.bank-content .bank-filters{width:100%;gap:7px;overflow:visible;margin-bottom:25px}.bank-content .bank-filters .tab{font-size:14px;padding:10px 16px;background:var(--surface-alt);border:1px solid transparent;border-radius:10px}.bank-content .bank-filters .tab.active{background:var(--blue-soft);border-color:color-mix(in srgb,var(--blue) 25%,var(--line));color:var(--blue);box-shadow:none}.bank-filter-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:22px 18px}.bank-filter-field{display:grid;gap:9px;min-width:0;font-size:13px;color:var(--muted)}.bank-filter-field select{width:100%;min-width:0;max-width:100%;min-height:46px;padding:11px 30px 11px 12px;background:var(--bg);color:var(--ink);border:1px solid var(--line);border-radius:10px;font-size:14px;text-overflow:ellipsis}.bank-filter-footer{display:flex;align-items:center;justify-content:flex-start;flex-wrap:wrap;gap:20px;padding-top:23px;margin-top:24px;border-top:1px solid var(--line)}.bank-filter-footer p{font-size:12px;color:var(--muted)}.bank-filter-footer .text-link{font-size:13px;flex:none;order:-1}.bank-content .bank-note{font-size:14px;line-height:1.8;margin:0 0 28px;max-width:none}.bank-content .bank-count{font-size:15px;display:flex;justify-content:space-between;gap:20px;margin:0 0 24px}.bank-count>span{font-size:13px}.bank-content .bank-topic{margin-bottom:42px}.bank-content .bank-topic-heading{margin-bottom:18px;gap:20px}.bank-content .bank-topic-heading .muted{font-size:13px}.bank-content .bank-topic-heading h2{font-size:21px;margin:7px 0}.bank-content .bank-topic-heading .text-link{font-size:14px}.bank-content .bank-row{padding:25px 28px}.bank-content .bank-name{font-size:14px;line-height:1.7;margin-top:9px}.bank-content .bank-conditions{font-size:13px;margin-top:10px}
@media(max-width:1150px){.bank-filter-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.bank-filter-panel{padding:22px}.bank-search-line{grid-template-columns:1fr;gap:11px}}
@media(max-width:700px){.bank-filter-panel{padding:20px 16px;margin-bottom:22px;border-radius:14px}.bank-search-line{margin-bottom:20px}.bank-search-line .search{font-size:16px}.bank-content .bank-filters{gap:6px;margin-bottom:22px}.bank-content .bank-filters .tab{padding:9px 12px;font-size:13px}.bank-filter-grid{grid-template-columns:1fr;gap:18px}.bank-filter-field{font-size:13px}.bank-filter-field select{font-size:16px;min-height:48px}.bank-filter-footer{align-items:flex-start;flex-direction:column;gap:14px;margin-top:22px;padding-top:20px}.bank-filter-footer p{font-size:12px}.bank-content .bank-note{font-size:13px;margin-bottom:25px}.bank-content .bank-count{font-size:14px;margin-bottom:22px}.bank-content .bank-topic-heading{align-items:flex-start;gap:12px;margin-bottom:15px}.bank-content .bank-topic-heading h2{font-size:19px}.bank-content .bank-topic-heading .muted{font-size:12px}.bank-content .bank-topic-heading .text-link{font-size:12px;padding-top:5px}.bank-content .bank-row{padding:22px 18px}.bank-content .bank-name{font-size:13px}.bank-content .bank-conditions{font-size:12px}}
.practice-wrap,.demo-card{container:reaction-workspace / inline-size}
.structure-lab-visual{background:var(--blue-soft)}
@container reaction-workspace (max-width:560px){.equation-stage{grid-template-columns:minmax(0,1fr);gap:10px}.reaction-arrow{max-width:100%;flex-direction:row;gap:12px}.reaction-conditions{max-width:70%;order:2}.equation-hint{grid-column:1}}
@media(max-width:700px){.sidebar>.utility-nav{display:flex}}
@media(min-width:701px) and (max-width:1100px){.topic-grid{grid-template-columns:1fr 1fr}.topic-symbol{width:62px;min-width:62px}.topic-copy h3{font-size:14px}.topic-card{gap:12px;padding:17px}.structure-workspace{grid-template-columns:190px minmax(0,1fr)}}
@media(max-width:700px){.topic-symbol{width:64px;min-width:64px;height:64px;padding:9px}.topic-symbol>span{font-size:23px}.utility-nav{display:flex;grid-column:1/-1;gap:4px;border-top:1px solid var(--line);padding-top:8px;margin-top:6px}.sidebar-bottom .utility-nav{display:none}.utility-nav .nav-link{justify-content:center;flex:1;font-size:11px;padding:9px 5px;gap:5px;white-space:nowrap}.utility-nav .nav-link svg{width:15px;height:15px}.equation-stage{grid-template-columns:minmax(0,1fr);gap:10px;padding:22px 16px 16px;min-height:245px}.equation-side{max-width:100%;width:100%;min-height:50px;font-size:28px}.reaction-arrow{max-width:100%;flex-direction:row;gap:12px;min-height:35px}.reaction-conditions{font-size:11px;max-width:65%;order:2}.arrow-line{font-size:34px}.equation-hint{font-size:10px;margin-top:8px!important}.exercise-mode{margin-left:0;font-size:11px}.structure-toggle{font-size:11px}.bank-content{padding-left:18px;padding-right:18px}.bank-row{padding:16px 14px;gap:6px}.bank-equation{font-size:18px;gap:6px 9px}.bank-topic-heading h2{font-size:17px}.bank-topic-heading .text-link{font-size:11px}.bank-topic-heading .text-link svg{display:none}.bank-topic-heading{gap:8px}.bank-filters .tab{padding:9px 12px;font-size:11px}.bank-name,.bank-conditions{font-size:11px}.structure-workspace{grid-template-columns:minmax(0,1fr);gap:16px}.molecule-picker{display:flex;overflow-x:auto;max-width:100%;padding-bottom:5px;scroll-snap-type:x proximity}.molecule-option{flex:none;max-width:195px;scroll-snap-align:start;padding:11px 13px;white-space:nowrap;border-color:var(--line);background:var(--surface);font-size:12px}.molecule-option span{max-width:100%;overflow:hidden;text-overflow:ellipsis}.structure-display{min-height:290px;padding:8px}.large-structure{height:280px}.structure-caption{padding:18px;align-items:flex-start;flex-direction:column}.structure-caption h2{font-size:16px}.structure-note{font-size:12px;margin-top:18px}.demo-card{padding:16px;margin-top:20px;border-radius:16px}.demo-card .key-row{gap:5px}.demo-card .key{min-width:0;flex:1;padding:0;height:37px}.demo-card .keyboard-top{align-items:flex-start;gap:8px;flex-wrap:wrap}.demo-card .keyboard-caption{font-size:10px}.demo-card .editor-tools{margin-left:auto}.learn-bottom{align-items:flex-start;flex-direction:column;gap:0}.driver-popover.reactor-tour{padding:18px;max-width:min(310px,calc(100vw - 28px));min-width:210px}.reactor-tour .driver-popover-title{font-size:16px}.reactor-tour .driver-popover-description{font-size:12px;line-height:1.65}.reactor-tour .driver-popover-footer button{padding:9px 10px}}
@media(prefers-reduced-motion:reduce){.driver-overlay,.driver-popover{transition:none!important;animation:none!important}}

.practice-wrap #feedback:empty,.demo-card #demo-feedback:empty{display:none}

.practice-shell{overflow-anchor:none}