/* Learning collection: readable controls, visible models, untimed exploration. */
.learn-hero{display:grid;grid-template-columns:1.2fr 1fr;gap:45px;padding:55px 0 35px;align-items:center}.learn-hero h1{font-size:clamp(45px,5.4vw,70px);line-height:1.01;max-width:720px}.learn-hero h1 em{font-family:Georgia,serif;font-weight:500;color:#51745b}.learn-hero p{max-width:580px;font-size:16px;color:var(--muted)}.learn-hero-art{background:#e6eddc;border:1px solid #d6decc;border-radius:28px;min-height:335px;position:relative;overflow:hidden}.learn-hero-art>svg{display:block;width:100%;height:335px}.learn-ribbon{display:flex;flex-wrap:wrap;gap:14px 28px;padding:20px 0;border-top:1px solid var(--line);border-bottom:1px solid var(--line);font-size:12px;font-weight:650}.learn-ribbon span{display:flex;align-items:center;gap:7px}.subject-grid{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:16px}.subject-card{padding:23px;background:var(--card);border:1px solid var(--line);border-radius:18px;min-height:215px;display:flex;flex-direction:column;position:relative;transition:transform .15s,border-color .15s}.subject-card:hover{border-color:#66846e;transform:translateY(-3px)}.subject-card.active{background:var(--forest);color:white}.subject-card.active p,.subject-card.active .subject-count{color:#d7e2cc}.subject-symbol{font:italic 36px/1 Georgia,serif;display:block;margin-bottom:25px;color:#568260}.subject-card.active .subject-symbol{color:var(--lime)}.subject-card h3{font-size:21px}.subject-card p{font-size:12px;color:var(--muted);margin-bottom:14px}.subject-count{margin-top:auto;font-size:10px;color:#657267;display:flex;justify-content:space-between}.learn-breadcrumb{display:flex;align-items:center;gap:10px;margin:22px 0;color:var(--muted);font-size:12px}.learn-tools-banner{background:#e9e4d8;border-radius:22px;padding:30px;display:flex;justify-content:space-between;gap:25px;align-items:center}.learn-tools-banner h3{font-size:27px}.learn-tools-banner p{font-size:13px;margin:0;max-width:600px}.learn-tools-banner .actions{flex-shrink:0}.learn-levels{display:flex;flex-wrap:wrap;gap:8px;margin:0 0 24px}.learn-levels button{border:1px solid var(--line);background:var(--card);border-radius:99px;padding:7px 15px;font-size:12px}.learn-levels button.active{background:var(--forest);color:white}.learn-progressbar{height:5px;border-radius:20px;background:#e3e8da;overflow:hidden;margin-top:10px}.learn-progressbar i{height:100%;display:block;background:#708b50}.learn-card-detail{font-size:10px;color:var(--muted);margin:10px 0 0}.learn-session{padding:24px}.learn-session-nav{display:flex;align-items:center;justify-content:space-between;gap:10px;font-size:11px;font-weight:600}.learn-session-nav label{white-space:nowrap}.learn-session-nav select{padding:5px 7px;font-size:11px;min-width:63px;margin-left:5px}.learn-dots{display:flex;gap:5px;margin:20px 0 27px}.learn-dots span{height:5px;flex:1;border-radius:5px;background:#dfe5d9}.learn-dots span.complete{background:#6c8a4e}.learn-dots span.current{background:#c36649}.learn-mission h2{font-size:30px;letter-spacing:-.045em;line-height:1.15;margin:10px 0 13px}.learn-mission p{font-size:14px;color:#58655c;max-width:730px}.learn-mission .caps{font-size:9px}#learn-work{border:0;min-width:0;padding:0;margin:0}#learn-work:disabled{opacity:.8}.learn-svg{width:100%;height:auto;display:block;margin:auto;max-height:460px}.learn-svg text{font-family:var(--font);fill:#274335}.learn-svg .graph-label{font-size:11px;fill:#6c7a6b}.learn-model{background:#f1f3e9;border:1px solid #dce3d3;border-radius:18px;padding:20px;margin:20px 0;overflow:hidden}.learn-controls{display:flex;flex-wrap:wrap;align-items:end;gap:12px;margin:18px 0}.learn-controls>.learn-field{flex:1;min-width:105px}.learn-field{display:flex;flex-direction:column;gap:5px;font-size:12px;font-weight:600;min-width:0}.learn-field input:not([type=range]),.learn-field select{width:100%;font-size:14px;padding:10px 12px}.learn-field input[type=range]{width:100%;padding:0;min-height:40px}.learn-field span{font-size:11px;color:#5f6f60}.learn-number{font:750 38px/1.3 var(--font);letter-spacing:-.04em;color:var(--forest)}.learn-formula{text-align:center;font-size:clamp(24px,4vw,40px);font-weight:700;letter-spacing:-.03em;padding:22px 10px;background:#edf2e0;border-radius:14px;overflow-wrap:anywhere}.learn-formula small{display:block;font-size:12px;font-weight:500;margin-top:10px;letter-spacing:0;color:var(--muted)}.learn-tokens{display:flex;flex-wrap:wrap;gap:10px;justify-content:center;padding:20px 0}.learn-token{width:70px;height:68px;font-size:24px;font-weight:700;background:var(--card);border:2px solid #ccd8c2;border-radius:12px;position:relative}.learn-token.active{border-color:var(--forest);background:var(--lime)}.learn-token.prime{border-color:#668555;background:#e8efda}.learn-token small{display:block;font-size:10px;font-weight:400}.learn-log{max-height:170px;overflow:auto;padding:12px 16px;font:12px/1.8 ui-monospace,monospace;background:#fffdf4;border-radius:10px;margin:12px 0}.learn-log>div{border-bottom:1px dashed #dde0d2;padding:3px 0}.learn-assist{display:flex;gap:9px;flex-wrap:wrap;margin-top:18px;align-items:center}.learn-assist .btn{font-size:11px;padding:10px 13px}.learn-assist #learn-next{margin-left:auto}.learn-feedback{border-radius:13px;padding:16px 18px;margin:18px 0 5px;font-size:13px}.learn-feedback.correct{background:#e4efcf;border:1px solid #aac080}.learn-feedback.retry{background:#fff0d9;border:1px solid #e4c497}.learn-feedback strong{font-size:14px}.learn-feedback p{margin:7px 0 0}.learn-hint{background:#f3eedf;border-left:3px solid #b79654;border-radius:0 10px 10px 0;padding:15px 18px;font-size:13px;margin:15px 0}.learn-concept{margin-top:18px;border-top:1px solid var(--line);border-bottom:0}.learn-concept summary{font-size:12px}.learn-concept p{font-size:12px;color:#5e6d60;margin-top:12px}.learn-concept a{font-size:11px;text-decoration:underline}.learn-table{width:100%;border-collapse:collapse;font-size:12px;margin:16px 0}.learn-table th,.learn-table td{padding:10px 7px;text-align:center;border-bottom:1px solid #dbe2d3}.learn-table th{font-size:10px;color:var(--muted);font-weight:650}.learn-table .ok{background:#e7efd9}.learn-table .off{background:#fcf0de}.learn-table input{width:80px;padding:7px 5px;text-align:center}.learn-note{font-size:11px;color:#637064;background:#f2f0e7;padding:11px 14px;border-radius:9px;margin:12px 0;line-height:1.7}.learn-inline-metrics{display:flex;flex-wrap:wrap;gap:14px;padding:16px 0}.learn-inline-metrics div{flex:1;min-width:88px;background:#f0f3e7;padding:12px;border-radius:10px}.learn-inline-metrics span{display:block;font-size:10px;color:var(--muted)}.learn-inline-metrics strong{font-size:22px}.learn-bar{display:flex;min-height:65px;gap:2px;margin:12px 0;border:2px solid #294f3c;border-radius:8px;overflow:hidden;background:#c9d5bd;padding:2px}.learn-bar button,.learn-bar span{flex:1;min-width:0;background:#fffdf2;border:0;display:grid;place-items:center;font-size:10px;padding:0}.learn-bar .filled{background:#8fae5e}.learn-bar .target{background:#e5a687}.learn-board{display:grid;gap:4px;margin:18px auto;width:min(100%,430px)}.learn-square{aspect-ratio:1;background:#f8f8f0;border:1px solid #bdcdb2;border-radius:4px;padding:0}.learn-square.active{background:#789c59;border-color:#35533d}.learn-axis{display:grid;grid-template-columns:repeat(18,minmax(0,1fr));gap:4px;min-width:500px}.learn-periodic-wrap{overflow-x:auto;padding:12px 0}.learn-element{height:52px;min-width:0;font-size:11px;background:#eef3dd;border:1px solid #c4d2b5;border-radius:5px;padding:3px 0}.learn-element strong{font-size:12px;display:block}.learn-element small{font-size:8px;display:block}.learn-element:hover{background:var(--lime)}.learn-element.selected{border:2px solid #31543e;background:#d8ebba}.learn-element.blank{background:#f2f1e9;opacity:.55;border-style:dashed}.learn-element-card{padding:22px;background:#193f33;color:white;border-radius:18px;max-width:220px;text-align:center;margin:15px auto}.learn-element-card .symbol{font:700 50px/1.1 var(--font);margin:10px 0}.learn-element-card .meta{font-size:13px}.learn-equation{display:flex;flex-wrap:wrap;gap:10px;align-items:center;justify-content:center;margin:22px 0}.learn-compound{padding:14px 10px;background:#edf2df;border-radius:13px;display:flex;gap:9px;align-items:center;font-size:22px;font-weight:600}.learn-compound input{width:58px;font-size:18px;padding:7px;text-align:center;background:#fffdf5}.learn-cell-options{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:9px;margin-top:14px}.learn-cell-options button{border:1px solid #c0d0b4;background:#f3f6ec;border-radius:9px;padding:12px 8px;font-size:11px}.learn-cell-options button.active{background:#d9edae;border-color:#3d6548}.learn-summary{padding:45px 25px;text-align:center}.learn-summary-symbol{font-size:70px;color:#678755}.learn-summary h2{font-size:44px;line-height:1.06}.learn-summary p{font-size:15px}.learn-summary-note{font-size:12px;max-width:500px;margin:0 auto 25px;color:var(--muted)}.learn-stats{display:grid;grid-template-columns:repeat(3,1fr);gap:15px;margin:25px 0}.learn-stat{background:var(--card);border:1px solid var(--line);padding:25px;border-radius:18px}.learn-stat strong{display:block;font-size:38px;line-height:1.4}.learn-stat span{font-size:12px;color:var(--muted)}.learn-desk-table{overflow-x:auto}.learn-desk-table .learn-table{min-width:590px;text-align:left}.learn-desk-table .learn-table td:first-child{text-align:left;font-weight:650}.learn-worksheet-form{background:var(--card);border:1px solid var(--line);padding:30px;border-radius:20px;max-width:850px}.learn-worksheet-form .learn-controls{margin-top:0}.learn-checklist{display:grid;grid-template-columns:1fr 1fr;gap:7px 16px;margin:20px 0}.learn-checklist label{font-size:12px;display:flex;align-items:center;gap:8px;padding:8px;border-radius:8px;background:#f5f5eb}.learn-toolbar{display:flex;gap:12px;flex-wrap:wrap;margin:22px 0}.learn-chart-track{height:28px;background:#e6ebdc;border-radius:5px;overflow:hidden}.learn-chart-track i{display:block;height:100%;background:#9db575}.learn-recipe{display:grid;grid-template-columns:1fr 1fr;gap:18px}.learn-recipe>div{background:#f4f1e5;border-radius:16px;padding:22px}.learn-recipe h3{font-size:23px}.learn-recipe ul{padding-left:20px;font-size:13px}.learn-visually-label{font-size:12px;color:#687863;text-align:center;margin:8px 0}.learn-compare{display:grid;grid-template-columns:1fr 1fr;gap:10px}.learn-compare>.learn-formula{font-size:28px}.learn-arrow{align-self:center;font-size:25px}.learn-input-row{display:flex;align-items:center;justify-content:center;gap:10px;flex-wrap:wrap}.learn-input-row input{width:95px}.learn-maze-footer{display:flex;flex-wrap:wrap;gap:10px;margin-top:15px}.study-hero-card{background:#e6eddc!important}.learn-session button[hidden],.learn-session div[hidden]{display:none!important}
@media(max-width:1000px){.subject-grid{grid-template-columns:repeat(3,1fr)}.learn-tools-banner{align-items:flex-start;flex-direction:column}.learn-hero{gap:25px}.learn-hero h1{font-size:54px}.learn-hero-art{min-height:300px}.learn-hero-art>svg{height:300px}}
@media(max-width:640px){.learn-hero{grid-template-columns:1fr;padding:32px 0 27px;gap:20px}.learn-hero h1{font-size:45px}.learn-hero p{font-size:14px}.learn-hero-art{min-height:240px}.learn-hero-art>svg{height:240px}.subject-grid{grid-template-columns:1fr 1fr;gap:12px}.subject-card{padding:18px 15px;min-height:208px}.subject-card h3{font-size:19px}.subject-card p{font-size:11px}.subject-symbol{font-size:32px;margin-bottom:18px}.learn-ribbon{font-size:10px;gap:12px}.learn-session{padding:17px 12px}.learn-mission h2{font-size:25px}.learn-mission p{font-size:12px}.learn-model{padding:12px;margin:16px 0}.learn-controls{gap:9px}.learn-controls>.learn-field{min-width:85px}.learn-controls .btn{font-size:11px;padding:11px}.learn-feedback{padding:13px;font-size:12px}.learn-token{width:58px;height:57px;font-size:22px}.learn-assist .btn{font-size:10px;padding:9px 11px}.learn-assist #learn-next{margin-left:0;width:100%}.learn-stats{gap:9px}.learn-stat{padding:15px 12px}.learn-stat strong{font-size:29px}.learn-stat span{font-size:10px}.learn-cell-options{grid-template-columns:repeat(2,1fr)}.learn-table{font-size:11px}.learn-table input{width:65px;padding:7px 3px}.learn-checklist{grid-template-columns:1fr}.learn-worksheet-form{padding:20px}.learn-recipe{gap:10px}.learn-recipe>div{padding:15px 12px}.learn-recipe ul{padding-left:15px;font-size:11px}.learn-compound{font-size:19px;padding:10px 8px}.learn-compound input{width:50px}.learn-summary h2{font-size:36px}.learn-tools-banner{padding:23px}.learn-tools-banner h3{font-size:24px}.learn-compare>.learn-formula{font-size:23px}.learn-hero .btn{font-size:12px}.learn-session-nav{font-size:10px}}