:root{--bg:#f5f6fa;--white:#fff;--ink:#20283d;--muted:#7b8397;--line:#e7eaf1;--purple:#6657da;--soft:#f0edff;--green:#258367;--green-soft:#e9f7f0;--orange:#a76920;--orange-soft:#fff4e1;--radius:20px}*{box-sizing:border-box}body{margin:0;background:var(--bg);color:var(--ink);font:15px/1.65 'Segoe UI',Arial,sans-serif}button,input,select{font:inherit}button,a,input,select{-webkit-tap-highlight-color:transparent}button{cursor:pointer}button:disabled{cursor:default;opacity:.4}a{color:var(--purple)}button:focus-visible,a:focus-visible,input:focus-visible,select:focus-visible{outline:3px solid #9988ed;outline-offset:3px}[hidden]{display:none!important}.skip{position:fixed;top:-70px;left:20px;background:white;z-index:100;padding:12px}.skip:focus{top:10px}.topbar{height:83px;padding:0 34px;display:flex;align-items:center;justify-content:space-between;background:var(--white);border-bottom:1px solid var(--line);position:relative;z-index:5}.brand{display:flex;align-items:center;gap:12px;text-decoration:none;color:var(--ink);font-size:21px;font-weight:750;letter-spacing:-.6px;line-height:1.15}.brand-icon{width:40px;height:40px;display:grid;place-items:center;background:var(--purple);color:white;border-radius:12px;font-size:27px;letter-spacing:-2px;padding-right:3px}.brand-sub{display:block;color:var(--muted);font-size:10px;letter-spacing:.1px;font-weight:500;margin-top:5px}.top-center{font-size:12px;color:var(--muted);display:flex;gap:8px;align-items:center}.live-dot,.save-dot{height:6px;width:6px;border-radius:50%;background:#54a98a;display:inline-block;flex-shrink:0}.icon-button{background:white;border:1px solid var(--line);border-radius:10px;padding:9px 13px;font-size:12px;color:var(--ink);display:flex;gap:16px;align-items:center}.app-shell{display:grid;grid-template-columns:310px minmax(0,1fr);max-width:1520px;margin:auto}.sidebar{background:var(--white);border-right:1px solid var(--line);height:calc(100dvh - 83px);position:sticky;top:0;display:flex;flex-direction:column;padding:27px 21px 15px}.overline{font-size:10px;font-weight:700;letter-spacing:1.4px;color:var(--muted)}.sidebar-title{display:flex;justify-content:space-between;align-items:center;gap:8px}.sidebar h2{font-size:18px;letter-spacing:-.5px;margin:5px 0 0}.count-badge{background:var(--soft);color:var(--purple);border-radius:8px;padding:3px 9px;font-size:12px;font-weight:700}.sidebar-copy{font-size:11px;color:var(--muted);margin:5px 0 20px}.progress-box{background:#f8f9fc;border:1px solid var(--line);border-radius:13px;padding:13px;margin-bottom:20px}.progress-box>div{display:flex;justify-content:space-between;font-size:11px}.progress-box strong{color:var(--purple)}progress{width:100%;height:5px;border:0;display:block;margin:10px 0;border-radius:10px;background:#e8e8f2;accent-color:var(--purple)}progress::-webkit-progress-bar{background:#e8e8f2;border-radius:10px}progress::-webkit-progress-value{background:var(--purple);border-radius:10px}progress::-moz-progress-bar{background:var(--purple);border-radius:10px}.progress-box small{font-size:10px;color:var(--muted)}.catalog-content{display:flex;flex-direction:column;flex:1;min-height:0}.search-wrap{display:flex;align-items:center;gap:8px;background:#f7f8fb;border:1px solid var(--line);border-radius:10px;padding:9px 10px}.search-wrap>span{font-size:21px;color:var(--muted);line-height:1}.search-wrap input{border:0;background:transparent;min-width:0;width:100%;font-size:11px;color:var(--ink);outline:0}.filter-label{font-size:10px;font-weight:600;color:var(--muted);margin-top:16px;margin-bottom:7px}.chips{display:flex;gap:6px;flex-wrap:wrap}.chip{background:white;color:var(--muted);font-size:10px;border:1px solid var(--line);border-radius:7px;padding:5px 9px}.chip.active{background:var(--soft);color:var(--purple);border-color:#d9d2ff;font-weight:650}.status-label{font-size:10px;color:var(--muted);display:flex;align-items:center;justify-content:space-between;gap:10px;margin:14px 0}.status-label select{font-size:11px;padding:6px 22px 6px 8px;border:1px solid var(--line);border-radius:7px;background:white;color:var(--ink);max-width:155px}.list-heading{display:flex;justify-content:space-between;font-size:9px;color:var(--muted);margin:7px 0}.task-list{overflow:auto;flex:1;min-height:100px;padding:3px 3px 12px 0;scrollbar-width:thin;scrollbar-color:#d9dce7 transparent}.task-item{display:flex;width:100%;gap:10px;align-items:center;border:1px solid transparent;background:white;padding:10px 9px;text-align:left;border-radius:11px;margin-bottom:4px;color:var(--ink)}.task-item:hover{background:#f7f8fc}.task-item.selected{background:var(--soft);border-color:#dcd5ff}.task-number{display:grid;place-items:center;background:#f2f4f8;border:1px solid #e8eaf1;border-radius:8px;font-size:11px;font-weight:650;width:29px;height:31px;flex-shrink:0}.selected .task-number{background:var(--purple);border-color:var(--purple);color:white}.task-item.is-solved .task-number{background:var(--green-soft);color:var(--green);border-color:#cce9dc}.task-item.is-mistake .task-number{background:var(--orange-soft);color:var(--orange)}.task-summary{min-width:0;flex:1}.task-summary strong{display:block;white-space:nowrap;overflow:hidden;text-overflow:ellipsis;font-size:11px;font-weight:600;line-height:1.5}.task-summary small{display:block;font-size:9px;color:var(--muted);margin-top:2px}.task-indicator{color:var(--green);font-size:13px}.sidebar-footer{display:flex;gap:6px;align-items:center;border-top:1px solid var(--line);padding-top:13px;font-size:9px;color:var(--muted);margin-top:9px}.empty{text-align:center;padding:25px 8px;color:var(--muted);font-size:12px}.empty p{font-size:11px}.text-button{border:0;background:transparent;color:var(--purple);font-size:11px}.mobile-catalog{display:none}main{padding:40px clamp(24px,4vw,70px) 20px;min-width:0;max-width:1100px;width:100%;margin:auto}.workspace-header{display:flex;justify-content:space-between;align-items:center;gap:25px;margin-bottom:34px}.workspace-header h1{font-size:clamp(23px,2.4vw,33px);line-height:1.25;letter-spacing:-1.1px;margin:8px 0 10px}.workspace-header p{color:var(--muted);font-size:12px;margin:0}.collection-label{background:#ece9fc;border:1px solid #e0daf8;color:var(--purple);border-radius:14px;min-width:66px;text-align:center;padding:10px}.collection-label span{font-size:9px;letter-spacing:2px;display:block}.collection-label b{font-size:28px;line-height:1.3;display:block;font-weight:550}.task-toolbar{display:flex;justify-content:space-between;gap:12px;align-items:center;margin-bottom:13px;font-size:11px;color:var(--muted)}.task-toolbar>div{display:flex;align-items:center;gap:12px}.task-toolbar a{text-decoration:none;font-size:11px}.category-pill{background:#eaf1fe;color:#5078b7;border-radius:6px;padding:4px 9px;font-size:10px}.category-pill[data-category="Звук"]{background:#fff0e3;color:#b77c38}.category-pill[data-category="Передача"]{background:#e6f5ee;color:#39866f}.problem-card{background:var(--white);border:1px solid var(--line);border-radius:var(--radius);padding:30px clamp(20px,3vw,38px);box-shadow:0 6px 24px #28394b03}.problem-heading{display:flex;align-items:center;justify-content:space-between;gap:12px}.state-badge{background:#f3f4f8;color:var(--muted);font-size:10px;border-radius:6px;padding:4px 9px}.state-badge.solved{background:var(--green-soft);color:var(--green)}.state-badge.mistake{background:var(--orange-soft);color:var(--orange)}.problem-card h2{font-size:clamp(24px,2.4vw,31px);letter-spacing:-.8px;line-height:1.3;margin:22px 0 17px}.statement{font-size:16px;line-height:1.95;margin:0;white-space:pre-line}.task-note{font-size:10px;color:var(--muted);margin-top:19px;padding-bottom:26px;border-bottom:1px solid var(--line)}.answer-block{padding-top:24px}#answer-form>label{font-size:12px;font-weight:650;display:block;margin-bottom:9px}#answer-unit{font-weight:400;color:var(--muted);margin-left:4px}.answer-row{display:flex;gap:10px}.answer-row input{min-width:0;flex:1;background:#fbfcfe;border:1px solid #dfe2ec;color:var(--ink);border-radius:10px;padding:12px 14px;font-size:14px;max-width:340px}.answer-row input::placeholder{color:#a2a8b8}.primary-button{background:var(--purple);color:white;border:1px solid var(--purple);border-radius:10px;font-size:12px;font-weight:600;padding:12px 20px;white-space:nowrap}.primary-button:hover{background:#5748c9}.answer-help{font-size:10px;color:var(--muted);margin:9px 0 0}.feedback{border-radius:10px;padding:12px 14px;font-size:12px;margin-top:16px}.feedback.success{background:var(--green-soft);color:var(--green)}.feedback.error{background:var(--orange-soft);color:#926020}.feedback.info{background:var(--soft);color:var(--purple)}.help-actions{display:flex;justify-content:space-between;gap:12px;align-items:center;margin-top:24px}.secondary-button{background:white;border:1px solid var(--line);border-radius:9px;color:#5b647b;padding:9px 13px;font-size:11px}.secondary-button:hover:not(:disabled){background:#f6f5ff;border-color:#d9d2f5;color:var(--purple)}.solution-button{border:0;background:transparent;color:var(--purple);padding:9px 0;font-size:11px;font-weight:600}.hint{background:#f9f6ee;border:1px solid #f0e5cf;border-radius:12px;padding:16px;font-size:13px;color:#8b734d;margin-top:16px}.solution{margin-top:25px;padding-top:24px;border-top:1px solid var(--line)}.solution h3{font-size:22px;letter-spacing:-.6px;margin:5px 0 18px}.solution ol{list-style:none;padding:0;margin:0;counter-reset:steps}.solution li{position:relative;padding:0 0 25px 43px;counter-increment:steps}.solution li::before{content:counter(steps);position:absolute;left:0;top:0;display:grid;place-items:center;width:28px;height:28px;border-radius:9px;background:var(--soft);color:var(--purple);font-weight:700;font-size:12px}.solution li h4{font-size:14px;margin:0 0 6px}.solution li p{font-size:12px;color:var(--muted);margin:0 0 12px}.formula{background:#f6f7fb;border:1px solid #eceef5;border-radius:10px;padding:12px 15px;font-size:14px;font-weight:600;color:#46506d;overflow-wrap:anywhere}.solution-answer{display:flex;align-items:center;gap:12px;background:var(--soft);border-radius:12px;padding:16px 20px;color:var(--purple)}.solution-answer span{font-size:12px}.solution-answer strong{font-size:24px}.solution-answer small{font-size:11px}.solution-note{font-size:10px;color:var(--muted);margin:13px 0 0}.task-navigation{display:flex;justify-content:space-between;align-items:center;margin-top:20px}.task-navigation>span{font-size:10px;color:var(--muted)}.learning-note{margin-top:32px;border-top:1px solid var(--line);padding:23px 0;display:flex;gap:13px;align-items:flex-start}.note-symbol{height:32px;min-width:32px;display:grid;place-items:center;background:#eeebfc;border-radius:10px;color:var(--purple)}.learning-note strong{font-size:11px;font-weight:600}.learning-note p{font-size:10px;color:var(--muted);margin:4px 0 0}footer{font-size:9px;color:var(--muted);padding-bottom:12px}footer a{color:var(--muted)}.guide{position:fixed;right:0;top:0;bottom:0;width:min(390px,100%);background:white;border-left:1px solid var(--line);box-shadow:-10px 0 60px #1723401a;z-index:20;padding:27px;overflow:auto}.guide-head{display:flex;justify-content:space-between;gap:12px;align-items:center;border-bottom:1px solid var(--line);padding-bottom:20px}.guide h2{font-size:22px;letter-spacing:-.6px;margin:4px 0}.guide-item{padding:21px 0;border-bottom:1px solid var(--line)}.guide-item>span{font-size:11px;color:var(--purple);font-weight:650}.guide h3{font-size:17px;margin:10px 0 7px;overflow-wrap:anywhere}.guide p{font-size:12px;color:var(--muted);margin:0}.units{background:#f6f7fb;border-radius:12px;padding:18px;margin-top:22px}.units b{font-size:12px}.units p{margin-top:7px}.noscript{background:#fff0df;padding:25px;text-align:center}@media(min-width:1500px){.topbar{padding-left:max(34px,calc((100vw - 1450px)/2))}}@media(max-width:1050px){.app-shell{grid-template-columns:280px minmax(0,1fr)}.sidebar{padding:23px 17px 15px}main{padding:30px 24px}.top-center{display:none}.workspace-header h1{font-size:25px}.collection-label{display:none}.answer-row{flex-wrap:wrap}.answer-row input{max-width:none;flex-basis:180px}.primary-button{flex-grow:1}.problem-card{padding:25px}.statement{font-size:15px}}@media(max-width:740px){.topbar{height:72px;padding:0 18px}.brand{font-size:19px}.brand-icon{height:35px;width:35px;font-size:24px}.icon-button{font-size:11px;padding:8px 10px}.app-shell{display:block}.sidebar{position:relative;top:auto;height:auto;border-right:0;border-bottom:1px solid var(--line);padding:18px}.sidebar-title h2{font-size:17px}.sidebar-copy{margin:3px 0 12px}.progress-box{margin-bottom:12px;padding:10px 12px}.progress-box small{display:none}.progress-box progress{margin-bottom:0}.catalog-content{display:none}.sidebar.catalog-open .catalog-content{display:flex}.task-list{max-height:330px;min-height:0}.mobile-catalog{display:flex;width:100%;justify-content:space-between;padding:10px 12px;background:var(--soft);border:1px solid #ded7fb;border-radius:9px;color:var(--purple);font-size:12px}.sidebar.catalog-open .mobile-catalog{margin-top:8px}.sidebar-footer{display:none}main{padding:25px 18px 16px}.workspace-header{margin-bottom:24px}.workspace-header h1{font-size:23px;letter-spacing:-.8px}.workspace-header p{font-size:11px}.problem-card{padding:22px 18px;border-radius:16px}.problem-card h2{font-size:24px;margin-top:18px}.statement{font-size:15px;line-height:1.85}.task-toolbar{font-size:10px}.task-toolbar>div{gap:8px}.task-toolbar a{font-size:10px}.answer-row{gap:9px}.answer-row input{width:100%;flex-basis:100%}.primary-button{width:100%}.solution li{padding-left:37px}.solution li h4{font-size:13px}.formula{font-size:12px;padding:12px}.task-navigation .secondary-button{padding:9px;font-size:10px}.learning-note{margin-top:25px}footer{font-size:9px}.guide{padding:22px}.list-heading{font-size:10px}.task-summary strong{font-size:12px}.task-summary small{font-size:10px}.chip{font-size:11px}.search-wrap input{font-size:13px}.status-label,.filter-label{font-size:11px}.status-label select{font-size:12px}}@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important}}

.formula{white-space:pre-line}

.guide{width:min(460px,100%)}.guide-intro{margin-top:17px!important;line-height:1.8}.guide-formula{font-size:16px;font-weight:650;line-height:1.9;color:#47516f;padding:12px 14px;background:#f5f4fc;border:1px solid #eae6f9;border-radius:10px;margin:12px 0;overflow-wrap:anywhere}.guide-formula sub{font-size:.7em}.symbols{display:grid;grid-template-columns:62px minmax(0,1fr);gap:9px 12px;font-size:12px;margin:18px 0}.symbols dt{font-weight:700;color:var(--purple);padding-top:1px}.symbols dd{margin:0;color:#626d85;line-height:1.7}.guide-item>p+p{margin-top:12px}.compression-example{padding:16px;background:#f8f7fc;border:1px solid var(--line);border-radius:13px;margin:20px 0}.compression-example>b{font-size:13px;line-height:1.6;display:block}.example-step{margin-top:17px}.example-step small{font-size:10px;font-weight:650;color:var(--purple)}.example-step .guide-formula{margin:6px 0 0;background:white;font-size:14px}.compression-example>p{margin-top:14px}.compression-compare{border-left:3px solid #b7a9ed;padding-left:13px;margin:20px 0}.compression-compare p+p{margin-top:10px}.unit-table{display:grid;margin:15px 0}.unit-table>div{display:grid;grid-template-columns:72px 1fr;gap:10px;padding:12px 0;border-bottom:1px solid #e1e4ed;font-size:12px}.unit-table b{font-size:12px}.unit-table span{color:#626d85;line-height:1.9}.guide .units{margin-top:20px;padding:18px}.guide .units>span{color:var(--purple)}.guide .units h3{font-size:15px;margin-top:22px}.guide .units .guide-formula{font-size:13px;background:white}.guide-notation{margin-top:14px!important;font-size:11px!important}.guide-item{scroll-margin-top:20px}

/* Mathematical notation in the reference panel. */
.guide .guide-formula{font-family:'Cambria Math','STIX Two Math','Times New Roman',serif;font-weight:400;font-size:21px;letter-spacing:0;line-height:1.9;padding:17px 15px;background:#faf9ff;border-color:#e5dff8;overflow-x:auto;overflow-wrap:normal}
.guide-formula math{font-family:'Cambria Math','STIX Two Math',math;font-size:21px;line-height:1.6;margin:0;text-align:left;color:#353550}
.guide-formula math+math{margin-top:14px}
.guide .math-symbol{font-family:'Cambria Math','STIX Two Math','Times New Roman',serif;font-size:1.15em;font-style:italic;font-weight:400;letter-spacing:.02em;color:#5543a9}
.guide .symbols{grid-template-columns:76px minmax(0,1fr);gap:14px 15px;align-items:start}
.guide .symbols dt{background:#f2effd;border:1px solid #e7e0fb;border-radius:10px;min-height:39px;display:flex;align-items:center;justify-content:center;padding:6px 8px;font-family:'Cambria Math','Times New Roman',serif;line-height:1.5;white-space:nowrap}
.guide .symbols dt .math-symbol{font-size:24px;color:#6653b9}
.guide .symbols dt sub{font-family:'Segoe UI',sans-serif;font-size:10px;font-weight:400;align-self:center;margin-top:8px}
.guide .symbols dd{padding-top:5px;font-size:12px}
.guide sub{font-style:normal;letter-spacing:0}
.compression-example .guide-formula{padding:15px 11px}
.guide .units .guide-formula math{font-size:18px}
@media(max-width:420px){.guide .guide-formula{padding:14px 10px}.guide-formula math{font-size:18px}.guide .symbols{grid-template-columns:68px minmax(0,1fr);gap:12px}.guide .units .guide-formula math{font-size:16px}}

.unit-example{margin:17px 0}.unit-example>small{font-size:11px;color:var(--purple);font-weight:600}.unit-example .guide-formula{font-size:17px!important;line-height:1.8;margin-top:7px}

.formula math{font-family:"Cambria Math","STIX Two Math",math;font-size:23px;font-weight:400;text-align:left;margin:5px 0 12px;overflow-x:auto}.formula-result{font-size:12px;font-weight:500;color:var(--muted);white-space:normal}@media(max-width:500px){.formula math{font-size:19px}}

.formula.substitution-layout{padding:0;background:transparent;border:0;white-space:normal}.given-values{padding:16px 18px;background:#f6f7fb;border:1px solid #e8eaf2;border-radius:12px}.formula-label{display:block;font-family:'Segoe UI',Arial,sans-serif;font-size:9px;letter-spacing:1.2px;font-weight:700;color:var(--muted);margin-bottom:11px}.given-line{white-space:pre-line;font-size:13px;line-height:1.9;overflow-wrap:anywhere}.given-line+.given-line{margin-top:7px}.substitution-card{margin-top:14px;padding:18px;background:#f0edff;border:1px solid #d8ceff;border-left:4px solid var(--purple);border-radius:12px}.substitution-card .formula-label{color:var(--purple)}.substitution-card math{font-size:22px;color:#4b3b94;margin:8px 0 3px}.substitution-card math mrow{white-space:nowrap}@media(max-width:600px){.substitution-card{padding:14px 12px}.substitution-card math{font-size:17px}.given-values{padding:14px}.given-line{font-size:12px}}

.calculation-chain math{font-size:24px;margin:10px 0 22px}.calculation-chain .formula-result{line-height:1.8}@media(max-width:500px){.calculation-chain math{font-size:20px}}

.calculation-chain math mtext{font-family:"Segoe UI",Arial,sans-serif;font-size:12px;color:var(--muted)}@media(max-width:500px){.calculation-chain math{font-size:17px}.calculation-chain math mtext{font-size:10px}}

.formula math{max-width:100%;overflow-x:auto;overflow-y:hidden;padding:6px 0}.formula.answer-formula{background:var(--green-soft);border-color:#cde9dc;color:var(--green)}.answer-formula math{color:var(--green)}.formula mtd{padding-inline:0;text-align:left}.solution li .formula{margin-top:12px}.solution li .substitution-card{margin-top:12px}

.answer-formula math mtext{font-family:"Segoe UI",Arial,sans-serif;font-size:12px;color:var(--muted)}

.statement:has(p){white-space:normal}.statement p{margin:0 0 14px}.statement p:last-child{margin-bottom:0}.statement sup{font-size:.72em;line-height:0;vertical-align:super}
.visually-hidden{position:absolute;width:1px;height:1px;padding:0;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}.tutor-launcher{position:fixed;right:24px;bottom:24px;z-index:25;width:58px;height:58px;background:var(--purple);color:white;border:1px solid #8071ec;border-radius:50%;box-shadow:0 6px 26px #6657da40;display:grid;place-items:center;transition:transform .15s}.tutor-launcher:hover{transform:translateY(-2px);background:#5849ca}.tutor-launcher svg{width:25px;height:25px}.tutor-launcher-dot{position:absolute;right:2px;top:2px;background:#7ed5ad;border:3px solid white;border-radius:50%;width:13px;height:13px}.tutor-panel{position:fixed;right:24px;bottom:96px;z-index:25;width:380px;max-width:calc(100vw - 32px);height:min(590px,calc(100dvh - 125px));background:white;border:1px solid #e2dff0;border-radius:22px;box-shadow:0 15px 65px #28244026;display:flex;flex-direction:column;overflow:hidden}.tutor-header{display:flex;align-items:center;gap:10px;padding:17px 18px;border-bottom:1px solid var(--line);flex-shrink:0}.tutor-avatar{height:37px;width:37px;border-radius:12px;background:var(--soft);color:var(--purple);display:grid;place-items:center;flex-shrink:0}.tutor-avatar svg{width:19px;height:19px}.tutor-header>div:nth-child(2){flex:1;min-width:0}.tutor-header h2{font-size:15px;letter-spacing:-.3px;margin:0}.tutor-header p{font-size:10px;color:var(--muted);margin:3px 0 0}.tutor-icon-button{border:0;background:#f5f5fa;border-radius:9px;height:31px;min-width:31px;display:grid;place-items:center;color:#6a6584;font-size:15px;padding:5px}.tutor-icon-button[aria-pressed="false"]{opacity:.55}.tutor-messages{flex:1;overflow-y:auto;padding:18px 15px;display:flex;flex-direction:column;gap:12px;scrollbar-width:thin}.tutor-bubble{padding:12px 14px;max-width:95%;border-radius:15px;font-size:13px;line-height:1.8;white-space:pre-wrap;overflow-wrap:anywhere}.tutor-bubble.assistant{background:#f5f5fb;color:#424761;border-bottom-left-radius:4px;align-self:flex-start}.tutor-bubble.user{background:var(--purple);color:white;border-bottom-right-radius:4px;align-self:flex-end}.tutor-status{font-size:10px;color:#87724a;padding:0 17px;margin:0;min-height:18px;line-height:1.6;flex-shrink:0}.tutor-form{padding:12px 15px 10px;flex-shrink:0}.tutor-form textarea{font:13px/1.6 'Segoe UI',Arial,sans-serif;resize:none;background:#fafafe;border:1px solid #e2e2ef;border-radius:11px;width:100%;min-height:65px;max-height:110px;padding:11px 12px;color:var(--ink)}.tutor-controls{display:flex;align-items:center;gap:8px;margin-top:8px}.tutor-mic{display:flex;gap:7px;align-items:center;padding:8px 10px;background:var(--soft);border:1px solid #e0d8ff;border-radius:9px;color:var(--purple);font-size:11px}.tutor-mic svg{width:15px;height:15px}.tutor-mic.listening{background:#ffeded;color:#bb4e60;border-color:#f3c8cf}.tutor-send{margin-left:auto;border:0;background:var(--purple);color:white;padding:9px 13px;border-radius:9px;font-size:11px;font-weight:600}.tutor-footer{display:flex;align-items:center;justify-content:space-between;gap:10px;font-size:9px;color:var(--muted);padding:10px 17px;border-top:1px solid var(--line);background:#fbfbfe}.tutor-footer button{background:none;border:0;color:var(--muted);font-size:9px;padding:2px}@media(max-width:500px){.tutor-launcher{right:16px;bottom:16px;width:54px;height:54px}.tutor-panel{right:16px;bottom:82px;height:min(580px,calc(100dvh - 104px));width:calc(100vw - 32px)}.tutor-form textarea{font-size:16px}.tutor-bubble{font-size:13px}.tutor-header{padding:14px}.tutor-mic{font-size:11px}}@media(prefers-reduced-motion:reduce){.tutor-launcher{transition:none}}

.account-box{margin-left:auto;display:flex;flex-wrap:wrap;align-items:center;justify-content:flex-end;gap:5px 12px;max-width:500px;font-size:12px}.account-link{color:#6553df;font-weight:700;text-decoration:none}.account-link:hover{text-decoration:underline}.account-box small{width:100%;text-align:right;color:#7d88a5;font-size:10px}.account-box>span{overflow:hidden;text-overflow:ellipsis;max-width:230px;white-space:nowrap}.account-box button{border:1px solid #ded8ff;border-radius:8px;background:#f6f3ff;color:#6553df;font:inherit;padding:6px 8px;cursor:pointer}.topbar{gap:16px}
@media(max-width:650px){.topbar{flex-wrap:wrap;height:auto;min-height:82px;padding:12px 16px;gap:10px}.account-box{order:3;width:100%;max-width:none;justify-content:flex-start;margin-left:0}.account-box small{text-align:left}.account-box>span{max-width:60vw}#guide-toggle{margin-left:auto}}

.collection-picker{display:block;font-size:11px;color:#7885a2;margin:14px 0 10px}.collection-picker select{display:block;width:100%;margin-top:7px;border:1px solid #ded8ff;border-radius:10px;background:#f4f1ff;color:#4f42bc;padding:11px 8px;font:inherit;font-size:12px;font-weight:600}.source-solution{font-size:15px;line-height:1.8;color:#28334d;overflow-wrap:anywhere}.source-solution p{font-size:inherit!important;color:inherit!important;line-height:inherit!important;margin:10px 0}.source-solution pre{white-space:pre;overflow-x:auto;background:#f5f6fa;padding:18px;border:1px solid #e4e7f3;border-radius:12px;font:13px/1.7 Consolas,monospace}.source-formula{max-width:100%;height:auto;vertical-align:middle}#task-statement table,.source-solution table{border-collapse:collapse;width:max-content;max-width:100%;margin:18px auto;font-size:13px}#task-statement td,#task-statement th,.source-solution td,.source-solution th{border:1px solid #dcdff0;text-align:center;min-width:38px;padding:10px 8px;white-space:normal}#task-statement th,.source-solution th{background:#f2efff;color:#5343b7;font-weight:600}#task-statement td:empty::after{content:'?';color:#a3abc0}#task-statement>div:has(table),.source-solution div:has(>table){overflow-x:auto}#logic-guide p{line-height:1.9}

.account-link{display:inline-flex;align-items:center;justify-content:center;min-height:38px;padding:0 18px;border:1px solid #c9bfff;border-radius:11px;background:#f3f0ff;color:#5c48d6;box-sizing:border-box;transition:background .15s,border-color .15s}.account-link:hover{background:#e9e3ff;border-color:#9c8beb;text-decoration:none}.account-link:focus-visible{outline:3px solid #c2b7ff;outline-offset:3px}#account-status:empty{display:none}

/* Python examples in the logic guide */
#logic-guide .guide-code { margin: 14px 0 24px; padding: 16px; border: 1px solid #e2ddff; border-radius: 12px; background: #f7f6fc; color: #263354; font: 12px/1.7 Consolas, monospace; overflow-x: auto; white-space: pre; tab-size: 4; }

.truth-walk{border:1px solid #dcd5ff;border-radius:16px;background:#fbfaff;padding:20px;margin:24px 0}.truth-walk h4{margin:0 0 10px}.truth-walk h5{font:600 13px/1.5 'Segoe UI',Arial,sans-serif;margin:0 0 8px;color:#5849bb}.truth-walk-tables{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:16px;margin:20px 0}.truth-walk-grid{min-width:0}.truth-walk-scroll{overflow-x:auto}.source-solution .truth-walk table{width:100%;margin:0;font-size:13px}.source-solution .truth-walk td,.source-solution .truth-walk th{min-width:30px;padding:9px 6px;transition:background-color .35s,color .35s}.truth-walk .walk-focus{background:#e7e0ff!important;color:#4b35bc!important}.truth-walk .walk-row td{background:#ede9ff}.truth-walk .walk-filled{color:#167858;font-weight:700}.truth-walk .walk-new{animation:truth-fill .7s ease-out}.truth-walk-caption{background:white;border-left:3px solid #7861e8;border-radius:8px;padding:14px;font-size:14px!important}.truth-walk-controls{display:flex;gap:8px;flex-wrap:wrap;margin-top:16px}.truth-walk-controls button{border:1px solid #d9d1ff;border-radius:9px;padding:9px 12px;color:#5b46c8;background:white;font:600 12px/1.5 'Segoe UI',Arial,sans-serif}.truth-walk-controls [data-walk=next]{background:#6855d8;color:white;border-color:#6855d8}.truth-walk-counter{font-size:12px!important;color:#7a7892!important}.truth-walk-answer{background:#e7f6ee;color:#187858!important;border-radius:10px;padding:12px}@keyframes truth-fill{from{background:#b9efd9;transform:scale(.85)}to{transform:scale(1)}}@media(max-width:1050px){.truth-walk-tables{grid-template-columns:1fr}}@media(prefers-reduced-motion:reduce){.truth-walk .walk-new{animation:none}.source-solution .truth-walk td,.source-solution .truth-walk th{transition:none}}

.source-solution .truth-walk-caption p{margin:0 0 10px;text-indent:1.5em}.source-solution .truth-walk-caption p:last-child{margin-bottom:0}#task-statement td.unknown-cell{color:#8892ad;font-weight:600}

/* Keep both truth tables aligned, with compact unbroken column labels. */
.source-solution .truth-walk table{table-layout:fixed;width:100%;min-width:240px}.source-solution .truth-walk th{white-space:nowrap;overflow-wrap:normal;word-break:normal;height:44px}.source-solution .truth-walk td{height:42px}.truth-walk-tables{align-items:start}.truth-walk-scroll{padding-bottom:2px}

.truth-walk-matches{margin:16px 0 20px}.truth-walk-pairs{display:grid;gap:8px}.truth-walk-pairs>p{font-size:12px!important;color:#7b7892!important}.truth-walk-pair{border:1px solid var(--match-color);border-left:5px solid var(--match-color);border-radius:9px;padding:10px 12px;background:white}.truth-walk-pair strong,.truth-walk-pair span{display:block}.truth-walk-pair strong{font-size:12px;color:var(--ink)}.truth-walk-pair span{font:11px/1.8 Consolas,monospace;color:#66718a;margin-top:4px;white-space:normal;overflow-wrap:anywhere}[data-match=blue]{--match-color:#6485e6}[data-match=green]{--match-color:#3ba783}[data-match=orange]{--match-color:#d79449}.source-solution .truth-walk tr[data-match]>:first-child{box-shadow:inset 4px 0 0 var(--match-color)}

.program-review{border:1px solid #e2dcff;border-radius:14px;padding:20px;margin:22px 0;background:#fbfaff}.program-review h3{font-size:17px;margin:0 0 8px}.program-review>p{font-size:12px;color:var(--muted);margin:0 0 16px}.program-review label{display:block;font-size:12px;font-weight:650;margin-bottom:8px}.program-review textarea{display:block;width:100%;resize:vertical;min-height:190px;padding:14px;border:1px solid #dcd8ed;border-radius:10px;background:white;color:var(--ink);font:13px/1.65 Consolas,monospace;white-space:pre;overflow-x:auto;tab-size:4}.program-actions{display:flex;align-items:center;justify-content:space-between;gap:12px;margin-top:12px}.program-actions button{border:0;border-radius:10px;background:var(--purple);color:white;padding:11px 15px;font-size:12px;font-weight:650}.program-actions span{font-size:10px;color:var(--muted)}#program-status{margin-top:14px;font-size:12px}#program-result{margin-top:16px;padding:16px;border-radius:12px;background:#fff4e4}#program-result[data-verdict=correct]{background:#e8f6ee}#program-result[data-verdict=incorrect]{background:#fff0f0}#program-result>strong{font-size:13px}#program-summary{font-size:13px;margin:8px 0}#program-details-toggle{border:1px solid #d4cbea;background:white;color:#604aba;border-radius:8px;padding:8px 12px;font-size:12px}#program-details h4{font-size:13px;margin:20px 0 10px}.program-issue{background:white;border:1px solid #e5dded;border-radius:10px;padding:12px;margin:8px 0}.program-issue button{border:0;background:#f1edff;color:#604aba;border-radius:7px;padding:5px 8px;font-weight:650}.program-issue p{font-size:12px;line-height:1.75;margin:8px 0}#program-source{list-style-position:outside;margin:12px 0;padding:12px 12px 12px 48px;background:white;border:1px solid #e1dce9;border-radius:10px;overflow-x:auto;font:12px/1.8 Consolas,monospace}#program-source li{padding:0 8px;white-space:pre;min-width:max-content}#program-source li::marker{color:#8b88a1}.program-source-line.is-error{background:#ffe0e0;border-left:3px solid #cf5965}.program-source-line:focus{outline:2px solid #7c68d8;outline-offset:1px}@media(max-width:600px){.program-review{padding:15px}.program-review textarea{font-size:13px}.program-actions{align-items:flex-start;flex-direction:column}}

#logic-guide .logic-guide-title{font-size:21px;line-height:1.35;color:var(--ink);font-weight:750;margin:0 0 22px;letter-spacing:-.4px}.guide-table-example{margin-top:24px;padding-top:18px;border-top:1px solid var(--line)}.guide-table-example h4{font-size:15px;margin:0 0 12px}.guide-table-scroll{overflow-x:auto;margin:14px 0 22px}.guide-table-scroll table{width:100%;min-width:270px;border-collapse:collapse;table-layout:fixed;font-size:12px}.guide-table-scroll th,.guide-table-scroll td{border:1px solid #ded9f0;padding:9px 5px;text-align:center;white-space:nowrap}.guide-table-scroll th{background:#f1edff;color:#5e4ec2}.guide-row-pairs{border-left:3px solid #8c79de;padding-left:12px;margin:16px 0}.guide-row-pairs p{font-size:11px!important;margin:6px 0}

.guide-animated-example{margin-top:26px}.guide-animated-example>h4{font-size:15px}.guide-animated-example .truth-walk{padding:14px;margin-top:12px}.guide-animated-example .truth-walk-tables{grid-template-columns:1fr;gap:18px}.guide-animated-example .truth-walk-caption p{font-size:12px!important}.guide-animated-example .truth-walk-pair span{font-size:10px}.guide-animated-example .truth-walk-controls button{padding:8px;font-size:11px}.guide-animated-example .truth-walk>p{font-size:12px!important}

.program-review-heading{display:flex;justify-content:space-between;align-items:center;gap:12px;margin-bottom:10px}.program-review-heading h3{margin:0}#program-collapse{flex-shrink:0;border:1px solid #d9d0f2;background:white;color:#6551c0;border-radius:8px;font-family:inherit;font-size:12px;line-height:1.5;padding:7px 10px}#program-review-body>#program-help{font-size:12px;color:var(--muted);margin:0 0 16px}.truth-walk-python .truth-walk-scroll{max-height:none;overflow-y:visible}.truth-walk-python thead th{position:sticky;top:0;z-index:1}@media(max-width:560px){.program-review-heading{align-items:flex-start;flex-direction:column}}

.source-solution .truth-walk-python tr.walk-excluded>*{background:#ffe7e8!important;color:#a0525b!important;text-decoration:line-through}.source-solution .truth-walk-python th.python-row-number{width:29px;min-width:29px;font-size:10px;color:#8a819a;padding:8px 3px;background:#f8f6fc}.source-solution .truth-walk-python tbody th.python-row-number{position:static;font-weight:500}.truth-walk-python .truth-walk-scroll{max-height:none!important;overflow-y:visible}

.source-solution .truth-walk[data-emphasize-rows=true] tr.walk-row>*{border-bottom:2px solid #8b72de;background-color:#eee8ff}.source-solution .truth-walk[data-emphasize-rows=true] tr.walk-row th.python-row-number{background:#eee8ff;color:#5942aa;font-weight:700}

.source-solution .truth-walk tr.walk-row>:first-child,.source-solution .truth-walk-python tbody tr:hover>:first-child{box-shadow:inset 4px 0 0 #6485e6}

.source-solution .truth-walk td{overflow-wrap:normal}.source-solution .truth-walk td.walk-filled{line-height:1.5}