:root{--ink:#1b1b1b;--muted:#5e5e5e;--paper:#ffffff;--line:#dedede;--good:#176f45;--bad:#a73030}*{box-sizing:border-box}body{margin:0;background:var(--paper);color:var(--ink);font:18px/1.4 system-ui,-apple-system,Segoe UI,sans-serif}button,input,select{font:inherit;color:inherit}button,a,input,select{touch-action:manipulation}button,.button{background:#fff;border:1px solid #c8c8c8;border-radius:9px;padding:10px 15px;cursor:pointer;font-weight:600}button:hover{background:#f0f0f0;border-color:#1b1b1b}button:disabled{opacity:.5;cursor:default}button.primary{color:#fff;background:var(--ink);border-color:var(--ink)}button.active{background:var(--ink);color:#fff}a{color:inherit}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible{outline:3px solid #707070;outline-offset:3px}header{max-width:1360px;margin:auto;padding:14px 25px;display:flex;justify-content:space-between;align-items:center;border-bottom:1px solid var(--line);gap:15px}.brand{text-decoration:none;font-size:15px;font-weight:850;letter-spacing:.15em}.brand span{letter-spacing:0;font-weight:500;color:var(--muted);margin-left:12px}nav{display:flex;align-items:center;gap:14px}nav a{font-size:15px;text-decoration:none}nav button{font-size:15px;padding:7px 12px}main{max-width:1300px;padding:22px 25px 28px;margin:auto}h1{font-size:clamp(27px,3vw,37px);margin:0 0 9px;letter-spacing:-.025em;line-height:1.2}h2{font-size:24px;margin:0 0 12px}h3{font-size:20px;margin:0 0 10px}p{margin:8px 0}.muted,small{color:var(--muted)}.top{display:flex;align-items:center;justify-content:space-between;gap:15px;margin-bottom:15px}.counter{font-size:14px;color:var(--muted);font-weight:650}.panel{border:1px solid var(--line);border-radius:16px;background:#fff;padding:20px}.split{display:grid;grid-template-columns:minmax(0,1.04fr) minmax(0,1fr);gap:18px}.home-grid{display:grid;grid-template-columns:repeat(4,1fr);gap:15px;margin-top:20px}.card{text-align:left;min-height:200px;padding:20px;border-radius:16px;background:white;display:flex;flex-direction:column}.card strong{font-size:22px;margin:11px 0 8px;line-height:1.2}.card .n{font-size:13px;color:var(--muted)}.card p{font-size:16px;font-weight:400;color:var(--muted)}.card svg{height:55px;width:100%;margin-top:auto}.tabs,.actions{display:flex;gap:8px;flex-wrap:wrap;margin:13px 0}.tabs button{font-size:16px}.fields{display:grid;grid-template-columns:1fr 1fr;gap:12px 15px}.field{display:block;font-size:16px}.field input,.field select{display:block;width:100%;min-width:0;padding:9px 10px;border:1px solid #9b9b9b;border-radius:8px;margin-top:5px;background:white}.field input.correct,.field select.correct{border-color:var(--good);background:#eef8f1}.field input.wrong,.field select.wrong{border-color:var(--bad);background:#fff3f1}.field.full{grid-column:1/-1}.feedback{font-size:16px;padding:12px 14px;border-radius:9px;margin:12px 0;background:#f0f0f0;min-height:47px}.feedback:empty{visibility:hidden}.feedback.good{background:#e8f5ec;color:var(--good)}.feedback.bad{background:#fff0ed;color:var(--bad)}.progress{height:4px;background:#e4e4e4;margin:11px 0 17px}.progress div{height:100%;background:var(--ink)}.visual{width:100%;display:block;max-height:325px}.visual svg{width:100%;height:auto;display:block;font-family:system-ui,sans-serif}.table{width:100%;border-collapse:collapse;font-size:16px}th,td{text-align:left;border-bottom:1px solid var(--line);padding:8px 10px}th{font-size:13px;color:var(--muted);font-weight:650}.scroll{overflow:auto;max-height:260px}details{margin:14px 0;font-size:16px}summary{cursor:pointer;font-weight:600}.periodic{display:grid;grid-template-columns:repeat(18,minmax(0,1fr));gap:3px;margin:12px 0}.periodic button{font-size:14px;padding:5px 0;border-radius:4px;line-height:1.2}.periodic button small{font-size:9px;display:block}.periodic button.selected{background:#1b1b1b;color:#fff}.periodic button.selected small{color:#ddd}.periodic .met{border-bottom:3px solid #313131}.periodic .non{border-bottom:3px dotted #313131}.periodic .semi{border-bottom:3px double #313131}.compact{display:flex;gap:12px;align-items:center;flex-wrap:wrap}.compact label{font-size:15px}.compact select{margin-left:5px;padding:7px;border:1px solid #9b9b9b;border-radius:7px;background:#fff}.chips{display:flex;gap:8px;flex-wrap:wrap}.chips span{padding:5px 9px;background:#f3f3f3;border-radius:6px;font-size:14px}.live-text{font-size:20px;font-weight:650;text-align:center;min-height:31px;margin:8px 0}.dotbuttons{display:flex;gap:5px;justify-content:center;flex-wrap:wrap}.dotbuttons button{padding:5px 10px;font-size:15px}.notice{border-left:3px solid #9c9c9c;padding:8px 12px;background:#ffffff;font-size:15px;margin:12px 0}.log{padding:10px 12px;background:#ffffff;border-radius:8px;font-size:15px;margin:9px 0}.sample-buttons{display:flex;gap:9px}.sample-buttons button{min-width:65px}.step{display:flex;gap:7px;flex-wrap:wrap;margin:12px 0}.step button{font-size:15px;padding:8px 13px}.readout{font-size:30px;font-weight:700;font-variant-numeric:tabular-nums}.unit{font-size:17px;font-weight:500}.legend{font-size:14px;color:var(--muted);text-align:center}.solution{font-size:16px;line-height:1.55}.pin{border:1px solid #d4d4d4;padding:10px;border-radius:8px;font-size:15px}.teacher{margin-top:23px;border-top:1px solid var(--line);padding-top:13px}.teacher p{font-size:15px}.warning{font-size:14px;background:#f3f3f3;padding:9px 12px;border-radius:8px}.saved{font-size:14px;color:var(--good)}svg .electron{fill:#1b1b1b}svg text{fill:#1b1b1b}svg .atom{fill:#ffffff;stroke:#383838;stroke-width:2}svg .glass{fill:#ffffff;stroke:#606060;stroke-width:2}svg .liquid{fill:#ebebeb;opacity:.7}svg .wire{stroke:#3c3c3c;stroke-width:3;fill:none}.motion{animation:travel 2s linear infinite}@keyframes travel{to{stroke-dashoffset:-60}}.pulse{animation:pulse 1.1s ease-in-out infinite}@keyframes pulse{50%{opacity:.25}}.droplet{animation:drip .7s linear infinite}@keyframes drip{from{transform:translateY(0);opacity:1}to{transform:translateY(55px);opacity:0}}
@media(min-width:1000px) and (max-height:820px){main{padding-top:15px}.panel{padding:16px}.visual{max-height:270px}.visual svg{max-height:270px}.field input,.field select{padding:7px 9px}.fields{gap:9px 13px}header{padding-top:9px;padding-bottom:9px}.home-grid{gap:12px}.card{min-height:170px}.card strong{font-size:21px}}
@media(max-width:1000px){.home-grid{grid-template-columns:repeat(2,1fr)}.split{grid-template-columns:1fr}.visual{max-height:none}.visual svg{max-height:340px}.periodic button{font-size:16px}.periodic button small{display:none}}
@media(max-width:560px){body{font-size:17px}header{padding:11px 14px;flex-wrap:wrap}.brand span{margin-left:5px;font-size:13px}main{padding:18px 14px}.home-grid{gap:10px}.card{padding:15px;min-height:190px}.card strong{font-size:20px}.card p{font-size:14px}.fields{gap:10px}.field{font-size:15px}.field input,.field select{font-size:16px;padding:8px}.panel{padding:15px}.top{align-items:flex-start}.tabs button{font-size:14px;padding:8px 10px}.periodic{gap:2px}.periodic button{font-size:11px;padding:7px 0}.periodic{min-width:410px}.periodic-wrap{overflow-x:auto}.visual svg{max-height:280px}.actions button{padding:9px 12px}.readout{font-size:27px}h2{font-size:22px}.sample-buttons button{min-width:55px}.step button{font-size:13px;padding:7px 9px}}
@media(prefers-reduced-motion:reduce){*{animation:none!important;transition:none!important}}
/* Apparatus and measurement controls share one restrained laboratory style. */
.split:has(.lab-stage){grid-template-columns:minmax(0,1.12fr) minmax(0,1fr)}.panel:has(.lab-stage){box-shadow:0 7px 24px #37373706;border-color:#dddddd}.lab-stage{height:350px;max-height:none;margin:13px 0 15px;border-radius:14px;overflow:hidden}.lab-stage svg{width:100%;height:100%;max-height:none;display:block}.panel:has(.lab-stage)>.compact{justify-content:space-between;gap:12px;padding-bottom:11px;border-bottom:1px solid #eaeaea}.panel:has(.lab-stage) .compact label{font-size:15px;font-weight:600;color:#5e5e5e}.panel:has(.lab-stage) .compact select{font-size:18px;font-weight:650;color:#313131;border-color:#cecece;padding:8px 10px}.panel:has(.lab-stage) .readout{font-size:27px;color:#313131}.panel:has(.lab-stage) .readout .unit{font-size:15px;font-weight:500;color:#696969}.panel:has(.lab-stage)>.actions{gap:7px;margin:10px 0}.panel:has(.lab-stage)>.actions button{font-size:16px;padding:10px 12px;border-color:#d4d4d4}.panel:has(.lab-stage)>.actions button.primary{background:#313131;border-color:#313131}.panel:has(.lab-stage)>.log{background:#ffffff;border:1px solid #e8e8e8;font-size:15px;color:#4c4c4c;margin-bottom:0}.step{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));gap:0;background:#eeeeee;border:1px solid #e0e0e0;padding:4px;border-radius:12px}.step button{background:transparent;border:0;border-radius:8px;color:#616161;font-size:16px;padding:9px 12px}.step button.active{background:#fff;color:#2f2f2f;box-shadow:0 2px 6px #31313110}.step button:hover{color:#2f2f2f;background:#ffffff}.step button.active:hover{background:#fff}.sample-buttons{gap:8px;margin:15px 0 7px}.sample-buttons button{background:#ffffff;border-color:#dedede;font-size:16px;min-width:104px}.sample-buttons button.active{background:#313131;border-color:#313131}.notebook-heading{border-top:1px solid #e7e7e7;padding-top:14px;margin-top:15px;font-size:18px;color:#373737}.observation-book{max-height:177px}.observation-book .log{margin:0;padding:10px 12px;border-radius:0;background:#ffffff;border-bottom:1px solid #e9e9e9;color:#4b4b4b}.observation-book .log b{display:inline-grid;place-items:center;background:#ececec;border-radius:5px;min-width:24px;height:24px;color:#3a3a3a;margin-right:3px}.panel:has(.lab-stage) .legend{font-size:14px;color:#717171}.lab-bubble{animation:lab-rise 1.8s ease-in infinite;transform-box:fill-box;transform-origin:center}@keyframes lab-rise{from{transform:translateY(0);opacity:0}20%{opacity:.9}to{transform:translateY(-60px);opacity:0}}#tit-table{max-height:180px}#cell-table .table th,#tit-table .table th{background:#ffffff;color:#666666}#tit-table .table td,#cell-table .table td{font-variant-numeric:tabular-nums;color:#3b3b3b}#tit-graph svg text{fill:#545454}#tit-volume{background:#ffffff;padding:7px 10px;border-radius:8px;white-space:nowrap}
@media(min-width:1000px) and (max-height:850px){.lab-stage{height:300px;margin-top:10px;margin-bottom:12px}.step{margin-top:10px;margin-bottom:12px}.step button{padding:7px 10px}.panel:has(.lab-stage)>.actions button{padding:8px 11px}.notebook-heading{padding-top:10px;margin-top:10px}.observation-book{max-height:145px}}
@media(max-width:1000px){.split:has(.lab-stage){grid-template-columns:1fr}.lab-stage{height:350px;max-width:700px;margin-left:auto;margin-right:auto}.panel:has(.lab-stage)>.compact{justify-content:flex-start;gap:20px}}
@media(max-width:560px){.lab-stage{height:265px;margin-top:9px;margin-bottom:10px}.step button{font-size:13px;padding:8px 4px}.panel:has(.lab-stage) .compact select{font-size:16px}.panel:has(.lab-stage)>.compact{gap:12px}.panel:has(.lab-stage)>.actions button{font-size:15px;padding:9px 10px}.panel:has(.lab-stage) .readout{font-size:24px}.sample-buttons button{min-width:0;flex:1;font-size:15px}.panel:has(.lab-stage)>.log{font-size:14px}.observation-book{max-height:200px}#tit-volume{padding:6px 9px}.panel:has(.lab-stage) .readout .unit{font-size:13px}}
@media(prefers-reduced-motion:reduce){.lab-bubble{animation:none;opacity:.8}}

@media(min-width:1000px) and (max-height:740px){.lab-stage{height:255px}}

/* Molempien luokka-asteiden yhtenäinen, rauhallinen työskentelyilme. */
:root{--ink:#2d2d2d;--muted:#5c5c5c;--line:#dddddd;--accent:#383838}
body{background:#ffffff;color:var(--ink);font:18px/1.45 system-ui,sans-serif}
header{max-width:1360px;margin:auto;padding:18px 26px;border-bottom:1px solid #e3e3e3}
main{max-width:1300px;margin:auto;padding:24px 26px 36px}
h1{font-size:clamp(28px,3vw,38px);line-height:1.15;letter-spacing:-.025em}
h2{font-size:24px;line-height:1.3;letter-spacing:-.015em}
.panel{border:1px solid var(--line);border-radius:18px;padding:22px;background:#fff;box-shadow:0 5px 20px #38383806}
button,.button,input,select{border-radius:10px}
button,.button{font-size:17px;min-height:44px;transition:background .15s,border-color .15s,box-shadow .15s}
button:hover:not(:disabled),.button:hover{border-color:#888888;box-shadow:0 3px 10px #3838380d}
button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible{outline:3px solid #808080;outline-offset:3px}
.primary{background:#383838;color:#fff;border-color:#383838}
.tabs{gap:8px}.tabs button,.tabs .button{font-size:17px}
.tabs .active{background:#383838;color:#fff}
.visual,.model{border-radius:14px;overflow:hidden;background:#ffffff}
.visual svg,.model svg{display:block;margin:auto}
.home-grid,.grid-home{gap:18px}
.card,.home-card{position:relative;border:1px solid var(--line);border-radius:18px;background:#fff;padding:22px;text-align:left;box-shadow:0 5px 20px #38383806}
.card:hover,.home-card:hover{border-color:#898989;box-shadow:0 8px 22px #38383812}
.card strong,.home-card h2{font-size:22px;line-height:1.25}
.card p,.home-card p{font-size:17px;line-height:1.45;color:var(--muted)}
.card svg{width:100%;height:112px;margin-top:14px}
.home-card svg{width:100%;height:136px;margin:12px 0}
.num,.n,.eyebrow{font-size:14px;font-weight:700;letter-spacing:.07em;color:#616161}
.feedback{font-size:18px;border-radius:12px}
.notice,.lab-hint,.lab-observation,.observation{font-size:16px;line-height:1.5}
.lab-fields label,.lab-controls label,.constants,.lab-state{font-size:15px}
.lab-fields select,.lab-controls select{font-size:18px;min-height:44px}
.lab-steps button,.step button{font-size:16px}
.lab-stage{border:1px solid #e3e3e3;border-radius:15px;background:#ffffff}
.legend,.tiny{font-size:15px}
.lab-notebook h3,.notebook h3{font-size:20px}
@media(min-width:1001px){.split{gap:22px}.grid-home{grid-template-columns:repeat(3,minmax(0,1fr))}.home-grid{grid-template-columns:repeat(4,minmax(0,1fr))}}
@media(max-width:1000px){.split,.lab-measure{grid-template-columns:1fr}.home-grid,.grid-home{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media(max-width:560px){header{padding:14px 16px}main{padding:18px 14px 28px}.panel{padding:17px}.home-grid,.grid-home{grid-template-columns:1fr}.card svg{height:125px}.home-card svg{height:140px}.lab-stage{height:285px}.actions{flex-wrap:wrap}.step{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media(prefers-reduced-motion:reduce){button,.button{transition:none}}

/* Valkoinen, mustavalkoinen kuvitus: väri vain kokeen havaintoihin. */
:root{--ink:#202020;--muted:#626262;--line:#d6d6d6;--accent:#242424}
body{background:#f5f5f5;color:#202020}
.panel,.card,.home-card{border-color:#d5d5d5;box-shadow:0 4px 18px #00000005}
.primary,.tabs .active{background:#242424;border-color:#242424;color:#fff}
.visual,.model,.lab-stage{background:#fff;border-color:#d5d5d5}
button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible{outline-color:#666}
.num,.n,.eyebrow{color:#666}.card p,.home-card p{color:#626262}
.sample.context-photo{width:min(100%,480px);aspect-ratio:3/2;background-size:cover;background-position:center;background-repeat:no-repeat;border-radius:12px;box-shadow:none}
.context-photo img{width:100%;height:100%;object-fit:cover;border-radius:12px;display:block}
.card-note{font-size:15px;line-height:1.45;color:#666}
/* Tarkasteluversion yhteinen tyyli. */
body{background:#f7f7f4;line-height:1.5}main{max-width:1240px}.panel{box-shadow:0 2px 12px #22222203}.card{text-decoration:none;min-height:180px}.card-arrow{margin-top:auto;font-size:24px;align-self:flex-end}.card strong{font-size:23px}.split{grid-template-columns:minmax(0,1.1fr) minmax(0,1fr)}.section-tabs{margin-bottom:24px}.art{margin:18px 0 0}.art img{display:block;width:100%;aspect-ratio:3/2;object-fit:contain;filter:grayscale(1);border-radius:10px}.art-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:18px;margin-top:15px}.art-card{margin:0;border:1px solid #ddd;border-radius:12px;padding:12px;background:white}.art-card .art{margin:0}.art-card figcaption{font-size:15px;margin-top:8px}.gallery{margin:24px 0}.quiz-list{display:grid;gap:18px;margin:20px 0}.quiz-question{margin:0;min-width:0}.quiz-question legend{font-size:21px;font-weight:650;line-height:1.45;max-width:100%;padding:0 8px}.quiz-options{display:grid;grid-template-columns:1fr 1fr;gap:12px;margin-top:12px}.quiz-options label{display:flex;align-items:flex-start;gap:10px;padding:12px;border:1px solid #d7d7d7;border-radius:9px;cursor:pointer;min-height:60px;font-size:18px}.quiz-options input{flex:none;margin:6px 0 0;accent-color:#343434}.quiz-options label:has(input:checked){background:#f1f1ed;border-color:#555}.quiz-question .feedback:empty{display:none}.fields{align-items:start}.formula-preview{font-size:21px;line-height:1.3;min-height:29px;display:block;margin:4px 0 0;color:#303030;font-style:normal}.formula-preview:empty{display:none}.field{font-size:17px}.equation{font-size:clamp(24px,3vw,32px);font-weight:650;padding:18px 0;font-style:normal}.visual{max-height:none;overflow:visible}.visual svg{max-height:340px;object-fit:contain}.scientific-model svg{max-height:300px}.painting-scene,.lab-stage{height:auto;max-height:none;margin:15px 0;border:1px solid #e5e5e5;border-radius:12px;overflow:hidden}.painting-scene svg,.lab-stage svg{height:auto;max-height:none;aspect-ratio:3/2;object-fit:contain}.drawing-layer{filter:grayscale(1)}.constants{margin:12px 0 20px;padding:0;list-style:none;font-size:17px}.constants li{padding:12px;background:#f5f5f2;border:1px solid #e5e5e5;border-radius:8px;margin-bottom:8px}.lab-split{grid-template-columns:minmax(0,1.65fr) minmax(0,1fr)}.compact select{max-width:100%;font-size:17px}.table{font-size:17px}.table th{font-size:15px}.log,.legend,.notice{font-size:16px}.rising-bubble{animation:rise-bubble 2.4s ease-in 3 forwards;transform-box:fill-box;opacity:.8}.falling-drops path{animation:drop-fall .65s linear infinite}.electron-stream circle{animation:electron-flow 1.2s linear infinite}.ion-drift circle{animation:ion-flow 2.5s linear infinite}.deposit-grow{animation:deposit 3.2s ease-in-out forwards}.solution-tint{transition:opacity 3s}
@keyframes rise-bubble{0%{transform:translateY(0);opacity:0}15%{opacity:.8}100%{transform:translateY(-170px);opacity:0}}
@keyframes drop-fall{from{transform:translateY(0);opacity:0}20%{opacity:.8}to{transform:translateY(100px);opacity:0}}
@keyframes electron-flow{from{transform:translateX(0);opacity:0}20%{opacity:1}to{transform:translateX(calc(var(--direction,1)*44px));opacity:0}}
@keyframes ion-flow{from{transform:translateX(0);opacity:0}20%{opacity:.7}to{transform:translateX(110px);opacity:0}}
@keyframes deposit{from{opacity:0}to{opacity:1}}
@media(max-width:1000px){.split,.lab-split{grid-template-columns:1fr}.art-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.visual svg{max-height:370px}.painting-scene svg,.lab-stage svg{max-height:none}.home-grid{grid-template-columns:repeat(2,minmax(0,1fr))}}
@media(max-width:600px){.quiz-options{grid-template-columns:1fr}.quiz-question legend{font-size:20px}.quiz-options label{font-size:18px}.art-grid{grid-template-columns:1fr}.fields{grid-template-columns:1fr}.home-grid{grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}.card{min-height:160px;padding:15px}.card strong{font-size:20px}.section-tabs{display:flex;gap:7px}.section-tabs button{font-size:16px;padding:9px 12px}.compact{display:grid;grid-template-columns:1fr 1fr;gap:10px}.compact label{font-size:16px;min-width:0}.compact select{display:block;width:100%;margin:5px 0 0}.readout{grid-column:1/-1}.panel{min-width:0}.sample-buttons{flex-wrap:wrap}.table td,.table th{padding:8px 6px}.periodic{gap:2px}.periodic button{font-size:11px;min-height:36px}.periodic button small{font-size:8px}.progress{margin-bottom:14px}}
@media(prefers-reduced-motion:reduce){.rising-bubble,.falling-drops path,.electron-stream circle,.ion-drift circle,.deposit-grow{animation:none;opacity:.8}.solution-tint{transition:none}}
.falling-drops path,.ion-drift circle{animation:none}
.task-navigation{gap:12px;align-items:center;justify-content:space-between}.task-arrows{display:flex;gap:8px}.task-arrows button{padding:7px 11px;font-size:16px;min-height:40px}.tension-series{padding:13px;border:1px solid var(--line);border-radius:10px;background:#f5f7fa;margin:0 0 18px}.tension-series h3{font-size:18px;margin:0 0 9px}.tension-series>div{display:flex;flex-wrap:wrap;gap:3px;align-items:start}.tension-series>div>span{padding:2px;font-weight:650;font-size:16px}.tension-series small{display:block;font-size:11px;line-height:1}.tension-series .hydrogen{border:1px solid #a9b3c1;border-radius:5px}.observation-field{display:block;margin-top:15px;font-size:17px}.observation-field textarea,.observation-field input{display:block;width:100%;margin-top:7px;box-sizing:border-box;border:1px solid var(--line);border-radius:8px;padding:10px;font:inherit;background:#fff}.buffer-stages{display:grid;grid-template-columns:1fr 1fr;gap:18px;margin-bottom:18px}.buffer-stages h2{margin-bottom:8px}.buffer-stages .lab-stage{margin:5px 0}.buffer-stages svg{max-height:270px}.mystery-intro{margin-bottom:18px}.mystery-intro .tension-series{margin-bottom:0}.quiz-options{grid-template-columns:1fr}.quiz-options button{text-align:left;min-height:48px}.sub-tabs{margin:12px 0 18px}.training-layout .art img{max-height:300px}.model-key{font-size:16px}
@media(max-width:700px){.task-navigation{align-items:stretch}.task-navigation label{width:100%;display:flex;align-items:center;gap:8px}.task-navigation select{flex:1;min-width:0;max-width:100%}.task-arrows{width:100%;justify-content:space-between}.buffer-stages{grid-template-columns:1fr}.tension-series h3{font-size:17px}.tension-series>div>span{font-size:16px}.tension-series>div{gap:3px}}

.application-split .art img{max-height:240px;aspect-ratio:auto;object-fit:contain}.application-split .art{margin-top:14px}.application-split .table{margin:16px 0}
/* MAFYKETOPIn yhteinen ilme. */
:root{--ink:#172033;--muted:#526071;--line:#dfe4eb;--accent:#172033;--good:#176f45;--bad:#a73030}
body{background:#f5f7fa;color:#172033;font-size:18px;line-height:1.43}
header{background:#fff;border-color:#dde3ea;padding:12px 25px}
main{max-width:1250px;padding:18px 25px 26px}
.panel,.card{background:#fff;border:1px solid #dfe4eb;border-radius:14px;padding:18px;box-shadow:0 2px 10px #2230440a}
button,.button{background:#fafbfc;border-color:#dfe4eb;color:#172033;min-height:42px}
.primary,.tabs .active,.example-steps .active{background:#172033;color:#fff;border-color:#172033}
button:hover:not(:disabled){background:#f4f7ff;border-color:#aebddd}.primary:hover:not(:disabled){background:#2c3a50;color:#fff}
h1{font-size:32px;margin-bottom:12px}h2{font-size:23px;margin:0 0 10px}
.section-tabs{margin:0 0 16px;gap:8px;flex-wrap:wrap}.section-tabs button{padding:8px 13px;font-size:17px}
.intro-layout{grid-template-columns:minmax(0,1.15fr) minmax(0,1fr);align-items:start;gap:18px}
.intro-layout p{margin:10px 0}.intro-example .art{margin:10px 0}.intro-example .art img{height:190px;aspect-ratio:auto;object-fit:contain}.intro-example .visual svg{max-height:245px}.intro-example .equation{font-size:23px;padding:8px 0}.intro-example>button{margin-top:10px}
.intro-layout b{font-weight:750}.example-steps{display:flex;gap:7px;margin:10px 0;flex-wrap:wrap}.example-steps button{font-size:16px;padding:7px 11px;min-height:38px}
.training-layout{grid-template-columns:minmax(0,1fr) minmax(0,1.1fr);align-items:start;gap:18px}.training-layout .visual svg{max-height:300px}.training-layout .art img{max-height:230px;aspect-ratio:auto;object-fit:contain}.training-layout p{margin:10px 0}.fields{gap:12px 14px}.field{font-size:17px;line-height:1.35}.field input,.field select{font-size:18px;padding:8px 10px;margin-top:5px}.dotbuttons{display:flex;gap:8px;flex-wrap:wrap;margin:9px 0}.dotbuttons button{padding:7px 10px;font-size:16px}.periodic-wrap{margin-top:12px}.periodic button{min-height:36px;padding:3px}.legend{font-size:16px}
.task-navigation{display:flex;align-items:center;justify-content:space-between;gap:15px;margin-bottom:14px;font-size:16px}.task-navigation label{display:flex;align-items:center;gap:9px;min-width:0}.task-navigation select{font-size:17px;padding:7px 10px;max-width:620px;min-width:0}.task-navigation span{color:#526071;white-space:nowrap}.charge-equation{font-size:22px;margin:10px 0}.katex{font-size:1.06em}.katex-display{margin:.4em 0}.formula-preview{font-size:22px;padding-top:3px}
.quiz-list{gap:14px;margin-top:14px}.quiz-question h2{font-size:21px;line-height:1.35;margin:0 0 11px}.quiz-options{gap:10px;margin-top:0}.quiz-options button{font-size:18px;font-weight:500;line-height:1.4;text-align:left;min-height:52px;padding:10px 13px;white-space:normal}.quiz-options .correct-choice,.quiz-options .correct-choice:disabled{background:#e5f3eb;color:#176f45;border:2px solid #176f45;opacity:1;font-weight:650}.quiz-options .wrong-choice{border-color:#a73030;background:#fff4f3}.quiz-locked .quiz-options button:disabled:not(.correct-choice){opacity:.58}.quiz-question .feedback{margin:10px 0 0;font-size:17px}.quiz-question .feedback:empty{display:none}
.name-table-grid{display:grid;grid-template-columns:1fr 1fr;gap:22px;grid-column:1/-1;width:100%}.formula-table{table-layout:fixed;margin:0}.formula-table th:first-child{width:55%}.formula-table td{padding:7px 10px;height:58px}.formula-table input{display:block;width:100%;min-width:0;padding:7px 9px;border:1px solid #9aa6b5;border-radius:8px;font-size:18px}.formula-table .formula-preview{font-size:20px}
.lab-split{grid-template-columns:minmax(0,1.45fr) minmax(0,1fr);gap:18px;align-items:start}.lab-split .art img{max-height:260px;aspect-ratio:auto;object-fit:contain}.lab-stage svg,.painting-scene svg{max-height:355px}.lab-split p{margin:10px 0}.lab-split .log{padding:9px 12px}.lab-split .actions button{font-size:16px;padding:8px 10px}.lab-split .fields{grid-template-columns:1fr}.step{margin:0 0 16px}.scroll{max-height:220px}
.application-split .art img{max-height:220px;object-fit:contain}.counter{color:#526071;font-size:16px;margin-bottom:12px}
@media(min-width:1050px) and (max-height:800px){header{padding-top:9px;padding-bottom:9px}main{padding-top:14px}h1{font-size:29px;margin-bottom:10px}.section-tabs{margin-bottom:12px}.panel{padding:15px}.intro-layout p{margin:8px 0}.intro-example .visual svg{max-height:215px}.intro-example .art img{height:165px}.training-layout .visual svg{max-height:265px}.lab-stage svg,.painting-scene svg{max-height:305px}}
@media(max-width:1000px){.intro-layout,.training-layout,.lab-split{grid-template-columns:1fr}.intro-example .visual svg{max-height:300px}.task-navigation select{max-width:calc(100vw - 150px)}.task-navigation{flex-wrap:wrap}.name-table-grid{grid-template-columns:1fr}.lab-split .fields{grid-template-columns:1fr 1fr}}
@media(max-width:600px){main{padding:15px 14px}header{padding:11px 14px}h1{font-size:28px}.panel{padding:16px}.quiz-options{grid-template-columns:1fr}.fields,.lab-split .fields{grid-template-columns:1fr}.section-tabs button{font-size:16px}.task-navigation label{width:100%;display:block}.task-navigation select{width:100%;max-width:100%;margin-top:6px}.quiz-options button{font-size:18px}.formula-table td{padding:7px 5px}.intro-example .art img{height:180px}}

/* Site-style multiple choice: one shared area, paired radio options. */
.quiz-list{display:block;background:#fff;padding:8px 28px;margin:14px 0 24px}
.quiz-list .quiz-question{border:0;border-radius:0;box-shadow:none;padding:22px 0 24px;margin:0;min-width:0}
.quiz-list .quiz-question+.quiz-question{border-top:1px solid #dce5e2}
.quiz-list .quiz-question legend{float:left;width:100%;padding:0;margin:0 0 15px;font-size:21px;font-weight:400;line-height:1.45}
.question-number{font-weight:700;color:#16847c;margin-right:5px}
.quiz-list .quiz-options{clear:both;display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:12px}
.quiz-list .quiz-options label{align-items:center;min-width:0;min-height:56px;padding:12px 15px;border:1px solid #d5dfdb;border-radius:10px;background:#fff;font-size:18px;font-weight:400;line-height:1.4}
.quiz-list .quiz-options input{appearance:auto;width:18px;height:18px;margin:0;flex:none;accent-color:#16847c}
.quiz-list .quiz-options label:focus-within{outline:2px solid #16847c;outline-offset:2px}
.quiz-list .quiz-options .correct-choice{background:#e5f3eb;border:2px solid #176f45;color:#176f45}
.quiz-list .quiz-options .wrong-choice{border-color:#a73030;background:#fff4f3}
.quiz-list .quiz-options input:disabled{opacity:1}
.quiz-list .quiz-locked label{cursor:default}
.quiz-list .quiz-question .feedback{clear:both;margin:8px 0 0}
@media(max-width:600px){.quiz-list{padding:4px 16px}.quiz-list .quiz-options{grid-template-columns:1fr}.quiz-list .quiz-question legend{font-size:20px}.quiz-list .quiz-options label{padding:11px 12px}}

/* Compact site-wide question format, four short questions per desktop viewport. */
.quiz-list{padding:0 22px;margin:10px 0 18px}.quiz-list .quiz-question{padding:10px 0 11px}.quiz-list .quiz-question legend{font-size:17px;line-height:1.3;margin-bottom:7px}.quiz-list .quiz-options{gap:6px 10px}.quiz-list .quiz-options label{font-size:16px;line-height:1.25;min-height:34px;padding:6px 11px;border-radius:8px}.quiz-list .quiz-options input{width:16px;height:16px}.quiz-list .quiz-question .feedback{font-size:15px;margin-top:4px}.section-tabs{gap:8px;flex-wrap:wrap}.section-tabs button{font-size:17px;padding:9px 13px}.name-table-grid>table+table{border-left:2px solid #aeb8bd}.name-table-grid>table+table td:first-child,.name-table-grid>table+table th:first-child{padding-left:16px}.example-formula{text-align:center;font-size:25px;margin:0 0 10px}.buffer-info{padding:14px 20px;margin-bottom:14px}.buffer-info p{margin:6px 0;font-size:17px}.naming-layout{grid-template-columns:minmax(0,2fr) minmax(210px,1fr)}.electro-half-reactions .equation{font-size:21px;overflow:auto}.charge-principle{margin:8px 0 4px}.intro-periodic{margin-top:12px;padding:14px}.intro-periodic .periodic{max-width:900px;margin:auto}.scene-label text{font-weight:500}
@media(max-width:600px){.quiz-list{padding:0 14px}.quiz-list .quiz-question legend{font-size:18px}.quiz-list .quiz-options label{font-size:17px;min-height:42px}.naming-layout{grid-template-columns:1fr}.name-table-grid>table+table{border-left:0;border-top:2px solid #aeb8bd}.section-tabs button{font-size:15px}.buffer-info p{font-size:16px}}

.formula-punctuation{white-space:nowrap}.formula-table input.correct{background:#e9f6eb;border-color:#4a9c65;color:#175e2c}.formula-table input.wrong{background:#fff0f0;border-color:#c65353}.live-equation{font-size:clamp(18px,2vw,27px);line-height:1.7}.coefficient-placeholder{color:#607579}.electro-half-reactions{margin:0 0 18px}.electro-half-reactions .equation{font-size:21px}@media(min-width:800px){.live-equation{white-space:nowrap}}

.coefficient-group{border:0;padding:0;margin:0;grid-column:1/-1}.coefficient-group legend{font-size:17px;margin-bottom:9px}.coefficient-inputs{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px}.coefficient-inputs input{width:100%;min-width:0}.coefficient-inputs .field{min-width:0}