@import "https://fonts.googleapis.com/css2?family=DM+Mono:wght@400;500&family=Manrope:wght@400;500;600;700;800&family=Noto+Sans+SC:wght@400;500;600;700;800&display=swap";:root{color:#14212b;font-synthesis:none;text-rendering:optimizelegibility;-webkit-font-smoothing:antialiased;background:#eef1ee;font-family:Manrope,Noto Sans SC,sans-serif}html,body,#root{min-width:0;min-height:100%;margin:0}body{min-height:100vh}:root{--ink:#14212b;--muted:#6d7a83;--line:#dfe4e6;--paper:#f7f8f5;--white:#fff;--teal:#087f79;--teal-dark:#05645f;--yellow:#f0b24c;--coral:#e66d4e}*{box-sizing:border-box}button,input,select{font:inherit}button{cursor:pointer}.app-shell{min-height:100vh;color:var(--ink);background:#eef1ee;font-family:Manrope,Noto Sans SC,sans-serif}.topbar{color:#f8faf8;background:#122b32;justify-content:space-between;align-items:center;height:80px;padding:0 42px;display:flex}.brand-lockup,.topbar-meta,.panel-heading,.card-topline,.conversation-header,.progress-label{align-items:center;display:flex}.brand-mark{color:#123037;background:var(--yellow);place-items:center;width:36px;height:36px;font-family:Noto Sans SC,sans-serif;font-size:19px;font-weight:800;display:grid;transform:rotate(-5deg)}.eyebrow,.section-kicker{color:var(--teal);letter-spacing:.12em;text-transform:uppercase;margin:0;font-family:DM Mono,monospace;font-size:11px}.topbar .eyebrow{color:#93c9c2;font-size:11px}h1,h2,h3,p{margin-top:0}h1{letter-spacing:-.03em;margin:2px 0 0;font-size:22px}h2{letter-spacing:-.03em;margin:5px 0 0;font-size:21px}h3{letter-spacing:-.02em;margin:7px 0 0;font-size:19px}.topbar-meta{color:#c7d4d1;gap:18px;font-size:13px}.status-dot{background:#65c58c;border-radius:50%;width:8px;height:8px;box-shadow:0 0 0 4px #65c58c24}.ghost-button,.text-button{color:inherit;background:0 0;border:0}.ghost-button{color:#f8faf8;border:1px solid #ffffff3d;padding:8px 12px;font-size:12px}.workspace{grid-template-columns:258px minmax(520px,1fr) 268px;gap:20px;width:min(1440px,100% - 64px);margin:28px auto 48px;display:grid}.panel{background:var(--white);border:1px solid #14212b14;box-shadow:0 9px 24px #152c300a}.sidebar{min-height:690px;padding:24px 16px 18px}.panel-heading{justify-content:space-between;padding:0 8px 22px}.book-tag,.pill,.result-badge{letter-spacing:.04em;border-radius:3px;align-items:center;padding:5px 8px;font-family:DM Mono,monospace;font-size:11px;display:inline-flex}.book-tag{color:var(--teal);background:#e9f2ef}.chapter-list{gap:7px;display:grid}.chapter-item{width:100%;color:var(--ink);text-align:left;background:0 0;border:1px solid #0000;border-radius:2px;grid-template-columns:31px 1fr;align-items:start;gap:8px;padding:13px 9px;display:grid}.chapter-item:hover{background:#f4f8f6}.chapter-item.active{background:#edf7f4;border-color:#a7d2ca}.chapter-number{color:var(--teal);padding-top:2px;font-family:DM Mono,monospace;font-size:11px}.chapter-item strong,.chapter-item small{display:block}.chapter-item strong{font-size:13px;line-height:1.45}.chapter-item small{color:var(--muted);margin-top:5px;font-size:11px;line-height:1.5}.sidebar-note{border-top:1px solid var(--line);color:var(--muted);gap:9px;margin:32px 8px 0;padding:12px 0;display:flex}.sidebar-note p{margin:0;font-size:12px;line-height:1.65}.note-icon{width:17px;height:17px;color:var(--teal);border:1px solid #9dc5bf;border-radius:50%;flex:none;place-items:center;font-family:Georgia,serif;font-size:11px;display:grid}.lesson-column{min-width:0}.lesson-header{justify-content:space-between;align-items:end;min-height:70px;padding:0 4px 18px;display:flex}.topic-select-wrap{align-items:center;gap:10px;display:flex}.topic-select-wrap label,.input-label{color:var(--muted);font-size:12px}.topic-select-wrap select{border:1px solid var(--line);color:var(--ink);background:#fff;border-radius:2px;padding:7px 28px 7px 10px;font-size:13px}.problem-card{padding:21px 24px 19px}.card-topline{justify-content:space-between;min-height:18px}.pill{color:#9c650f;background:#fff3d8}.muted{color:var(--muted);font-size:11px}.input-label{margin-top:19px;display:block}.expression-input{width:100%;color:var(--ink);letter-spacing:-.04em;background:0 0;border:0;border-bottom:2px solid #c6d2d0;outline:0;margin-top:7px;padding:7px 0 9px;font-size:31px;font-weight:700}.expression-input:focus{border-color:var(--teal)}.example-row{color:var(--muted);flex-wrap:wrap;align-items:center;gap:6px;margin-top:15px;font-size:11px;display:flex}.example-row button{color:var(--teal-dark);background:#f8fbfa;border:1px solid #d4e2df;border-radius:2px;padding:5px 8px;font-family:DM Mono,monospace;font-size:11px}.conversation{flex-direction:column;min-height:474px;margin-top:16px;padding:21px 24px 20px;display:flex}.conversation-header{justify-content:space-between}.step-counter{color:var(--teal);font-family:DM Mono,monospace;font-size:11px}.message-list{flex:1;align-content:start;gap:11px;margin-top:23px;padding-bottom:16px;display:grid}.message{gap:10px;max-width:88%;display:flex}.message.student{flex-direction:row-reverse;justify-self:end}.message p{color:#35454c;background:#f1f6f4;border-radius:2px 8px 8px;margin:0;padding:11px 13px;font-size:14px;line-height:1.7}.avatar{background:var(--teal);color:#fff;border-radius:50%;flex:none;place-items:center;width:25px;height:25px;font-family:Noto Sans SC,sans-serif;font-size:11px;display:grid}.message.student .avatar{background:var(--yellow);color:#5b430e}.answer-row{border-top:1px solid var(--line);grid-template-columns:minmax(0,1fr) auto auto;gap:8px;padding-top:15px;display:grid}.answer-row input{border:1px solid var(--line);border-radius:2px;outline:0;min-width:0;padding:11px 12px;font-size:14px}.answer-row input:focus{border-color:#72bdb2;box-shadow:0 0 0 3px #087f7914}.primary-button,.secondary-button{border-radius:2px;padding:11px 14px;font-size:12px;font-weight:700}.primary-button{border:1px solid var(--teal);background:var(--teal);color:#fff}.primary-button:hover{background:var(--teal-dark)}.secondary-button{color:var(--teal-dark);background:#f6fbf9;border:1px solid #b9d3ce}.insight-column{align-content:start;gap:14px;display:grid}.insight-card{padding:18px}.result-badge{color:var(--muted);background:#eef3f1}.result-badge.correct{color:#267448;background:#e1f4e8}.result-badge.incorrect{color:#ad5b34;background:#fff0e8}.insight-copy{color:var(--muted);margin:12px 0 17px;font-size:13px;line-height:1.75}.progress-track{background:#edf1ef;height:5px;overflow:hidden}.progress-track span{background:var(--teal);height:100%;transition:width .3s;display:block}.progress-label{color:var(--muted);justify-content:space-between;margin-top:8px;font-family:DM Mono,monospace;font-size:11px}.progress-label strong{color:var(--teal);font-weight:500}.empty-state{color:var(--muted);margin:17px 0 2px;font-size:11px;line-height:1.7}.practice-item,.history-item{border:0;border-bottom:1px solid var(--line);width:100%;color:var(--ink);text-align:left;background:0 0;justify-content:space-between;align-items:center;display:flex}.practice-item{padding:12px 0;font-family:DM Mono,monospace;font-size:12px}.practice-item span:last-child{color:var(--teal);font-family:Manrope,sans-serif;font-size:10px}.history-card .text-button{color:var(--teal);font-size:10px}.history-item{color:var(--muted);padding:8px 0;font-family:DM Mono,monospace;font-size:11px}.history-item:hover,.practice-item:hover{color:var(--teal-dark)}.history-item span{color:var(--teal)}.tab-bar{border:1px solid var(--line);background:#f3f6f4;gap:5px;margin-top:16px;padding:4px;display:flex}.tab-bar button{color:var(--muted);background:0 0;border:0;flex:1;padding:10px 8px;font-size:11px;font-weight:700}.tab-bar button.active{background:var(--white);color:var(--teal-dark);box-shadow:0 2px 7px #14323014}.feature-stack{gap:14px;margin-top:16px;display:grid}.practice-flow{grid-template-columns:1.2fr repeat(5,1fr);gap:6px;padding:7px;display:grid}.practice-flow button{min-height:58px;color:var(--muted);text-align:left;background:#f5f8f6;border:1px solid #0000;padding:8px 6px}.practice-flow button strong,.practice-flow button small,.practice-flow button em{display:block}.practice-flow button strong{color:var(--teal-dark);font-size:14px}.practice-flow button small{margin-top:5px;font-size:10px;font-weight:700}.practice-flow button em{color:var(--muted);margin-top:3px;font-size:9px;font-style:normal}.practice-flow button.active{color:var(--teal-dark);background:#edf8f4;border-color:#7bb9ae}.practice-flow button:disabled{cursor:not-allowed;opacity:.42}.knowledge-lesson{padding:24px}.knowledge-lesson h3{margin:6px 0 12px;font-size:20px}.lesson-text{color:#405159;max-width:620px;margin:0;font-size:14px;line-height:1.9}.guide-block,.guide-example,.guide-visual,.guide-pitfall{color:#405159;background:#f7faf8;border-left:3px solid #9ecac2;gap:5px;margin-top:17px;padding:12px 14px;font-size:12px;line-height:1.7;display:grid}.guide-block strong,.guide-example strong,.guide-visual strong,.guide-pitfall strong{color:var(--teal-dark);font-size:11px}.guide-block .step-list{margin:0}.guide-example{border-left-color:#8fb8d4}.guide-visual{border-left-color:#d8b56b}.guide-pitfall{background:#fff8f4;border-left-color:#dc927e}.lesson-topics{color:var(--muted);flex-wrap:wrap;align-items:center;gap:8px;margin:20px 0;font-size:11px;display:flex}.lesson-topics strong{color:var(--teal-dark);background:#f4fbf8;border:1px solid #cde4de;padding:5px 9px;font-size:11px;font-weight:700}.stage-heading{justify-content:space-between;align-items:center;padding:4px 2px;display:flex}.stage-heading h3{margin:5px 0 0;font-size:18px}.stage-tip{color:var(--muted);text-align:center;margin:0;font-size:11px}.stage-next-button{justify-self:start}.chapter-question-list{gap:12px;display:grid}.chapter-question{padding:18px 21px}.question-meta{align-items:center;gap:9px;display:flex}.chapter-question h3{margin:14px 0;font-size:16px;line-height:1.6}.option-list{grid-template-columns:repeat(3,1fr);gap:8px;display:grid}.option-list button{border:1px solid var(--line);color:var(--ink);text-align:left;background:#fafcfa;border-radius:2px;padding:10px;font-size:12px}.option-list button:hover,.option-list button.selected{color:var(--teal-dark);background:#edf8f4;border-color:#78b9ae}.chapter-answer{border:1px solid var(--line);border-radius:2px;outline:0;width:min(360px,100%);padding:10px 11px;font-size:13px}.chapter-check{margin-top:10px}.hint-button{color:var(--teal);background:0 0;border:0;margin-top:10px;padding:6px 0;font-size:11px;font-weight:700;display:block}.hint-button:disabled{color:var(--muted);cursor:default}.question-hint{color:var(--teal-dark);background:#f5faf8;gap:8px;margin-top:9px;padding:9px 11px;font-size:11px;line-height:1.6;display:flex}.question-hint strong{white-space:nowrap}.chapter-feedback{gap:10px;margin-top:13px;padding:10px 12px;font-size:12px;line-height:1.6;display:flex}.chapter-feedback.correct{color:#267448;background:#eaf7ef}.chapter-feedback.incorrect{color:#ad5b34;background:#fff1e8}.chapter-feedback span{color:inherit;opacity:.85}.stage-summary{color:#405159;background:#f5faf8;padding:14px 17px;font-size:12px;line-height:1.7}.stage-summary p{margin:0}.stage-summary .section-kicker{margin-bottom:4px}.feature-empty{text-align:center;place-content:center;justify-items:center;min-height:474px;padding:30px;display:grid}.feature-empty h3{margin:14px 0 7px}.feature-empty p{max-width:280px;color:var(--muted);margin:0;font-size:12px;line-height:1.7}.feature-icon{width:39px;height:39px;color:var(--teal);border:1px solid #9ecac2;place-items:center;font-family:DM Mono,monospace;font-size:11px;display:grid}.analysis-hero{justify-content:space-between;align-items:center;padding:21px 24px;display:flex}.analysis-hero h3{margin:5px 0}.analysis-hero p:not(.section-kicker){color:var(--muted);margin:0;font-size:11px}.analysis-grid,.summary-grid{grid-template-columns:1.15fr .85fr;gap:14px;display:grid}.feature-card{padding:20px 22px}.step-list,.pitfall-list{color:#405159;gap:12px;margin:15px 0 0;padding-left:22px;font-size:12px;line-height:1.65;display:grid}.step-list li::marker{color:var(--teal);font-family:DM Mono,monospace}.pitfall-list{padding-left:18px}.pitfall-list li::marker{color:var(--coral)}.answer-reveal{border-top:1px solid var(--line);color:var(--muted);justify-content:space-between;align-items:center;margin-top:20px;padding-top:13px;font-size:11px;display:flex}.answer-reveal strong{color:var(--teal-dark);font-family:DM Mono,monospace;font-size:16px}.extension-grid{grid-template-columns:repeat(2,1fr);gap:12px;display:grid}.extension-card{min-height:145px;color:var(--ink);text-align:left;border:1px solid #14212b14;padding:17px 18px;position:relative}.extension-card:hover,.extension-card.selected{background:#f4fbf8;border-color:#7bb9ae}.extension-kind{width:21px;height:21px;color:var(--teal);background:#e4f3ef;place-items:center;font-family:DM Mono,monospace;font-size:10px;display:inline-grid}.extension-title{color:var(--muted);margin-top:12px;font-size:10px;display:block}.extension-card strong{margin-top:8px;font-size:15px;line-height:1.55;display:block}.extension-card small{color:var(--teal);margin-top:9px;font-size:10px;display:block}.selected-extension{padding:20px 22px}.selected-extension h3{color:var(--teal-dark);margin:7px 0}.selected-extension p:not(.section-kicker){color:var(--muted);margin:0;font-size:12px;line-height:1.7}.extension-answer-row{gap:8px;margin-top:17px;display:flex}.extension-answer-row input{border:1px solid var(--line);border-radius:2px;outline:0;flex:1;min-width:0;padding:10px 11px;font-size:13px}.extension-answer-row input:focus{border-color:#72bdb2;box-shadow:0 0 0 3px #087f7914}.extension-feedback{margin:12px 0 0;font-size:12px;line-height:1.6}.extension-feedback.correct{color:#267448}.extension-feedback.incorrect{color:#ad5b34}.quick-link{border:0;border-bottom:1px solid var(--line);width:100%;color:var(--ink);text-align:left;background:0 0;justify-content:space-between;align-items:center;padding:12px 0;font-size:12px;display:flex}.quick-link:last-child{border-bottom:0}.quick-link span{color:var(--teal);font-size:15px}.summary-copy{color:var(--muted);margin:13px 0 0;font-size:12px;line-height:1.75}.insight-list{color:#405159;gap:10px;margin:15px 0 0;padding:0;font-size:12px;line-height:1.65;list-style:none;display:grid}.insight-list li{padding-left:15px;position:relative}.insight-list li:before{content:"✦";color:var(--teal);position:absolute;left:0}.compact{margin-top:12px}.next-step-card{justify-content:space-between;align-items:start;gap:20px;display:flex}.ai-summary{background:#f5f1e7;max-width:235px;padding:12px 14px}.ai-summary p{color:#665b49;margin:9px 0 0;font-size:11px;line-height:1.7}@media (width<=1100px){.workspace{grid-template-columns:220px minmax(480px,1fr)}.insight-column{grid-column:1/-1;grid-template-columns:repeat(3,1fr)}.sidebar{min-height:auto}}:root{--ink:#244052;--muted:#718391;--line:#dce9ed;--paper:#f3f9fc;--teal:#159c92;--teal-dark:#08746f;--yellow:#ffc857;--coral:#f47d68}body{background:#eaf5f9}.app-shell{background:radial-gradient(circle at 8% 8%,#ffde8959,#0000 24%),radial-gradient(circle at 92% 16%,#bae4ff8c,#0000 28%),linear-gradient(135deg,#eef9fb 0%,#f8fbf6 52%,#fff8ea 100%)}.topbar{background:linear-gradient(120deg,#1d5964 0%,#237b7c 58%,#2d8b83 100%);height:94px;padding:0 42px;position:relative;overflow:hidden;box-shadow:0 8px 22px #1c5c652e}.topbar:after{content:"✦   ○   ✦";color:#ffffff1f;letter-spacing:22px;font-size:74px;position:absolute;bottom:-22px;right:34%;transform:rotate(-9deg)}.brand-lockup,.topbar-meta{z-index:1;position:relative}.brand-lockup{gap:15px}.brand-mark{color:#855f16;background:linear-gradient(145deg,#ffe58c,#ffc857);border-radius:16px 16px 16px 6px;width:48px;height:48px;font-size:25px;transform:rotate(-6deg);box-shadow:0 5px #d99d37}.brand-subtitle{color:#c9f1eb;letter-spacing:.04em;margin:3px 0 0;font-size:11px;font-weight:600}.topbar .eyebrow{color:#b8e8df}.topbar-meta{gap:14px}.streak-badge{color:#fff6cf;background:#ffffff1f;border:1px solid #ffffff40;border-radius:999px;padding:7px 11px;font-size:11px;font-weight:700}.ghost-button{border-radius:999px;transition:transform .18s,background .18s}.ghost-button:hover{background:#ffffff1f;transform:translateY(-2px)}.workspace{margin-top:32px}.panel{border-color:#3477811f;border-radius:19px;box-shadow:0 12px 28px #2a687314}.sidebar{background:linear-gradient(#fffffffa,#f5fcfff5)}.book-tag,.pill{border-radius:999px}.chapter-list{gap:8px}.chapter-item{border-radius:14px;transition:transform .18s,background .18s,box-shadow .18s}.chapter-item:hover{background:#f0fbfa;transform:translate(3px)}.chapter-item.active{background:linear-gradient(100deg,#e9fbf6,#f2f9ff);border-color:#8ed5ca;box-shadow:0 6px 12px #1d89841a}.chapter-number{background:#e5f5f3;border-radius:9px;place-items:center;width:27px;height:27px;padding:0;display:inline-grid}.chapter-item.active .chapter-number{background:var(--yellow);color:#795616}.note-icon{background:#fff1c9;border:0;font-size:12px}.lesson-header{min-height:78px}.lesson-header h2{font-size:24px}.topic-select-wrap select{background:#ffffffe6;border-radius:11px}.problem-card{background:linear-gradient(135deg,#fff 0%,#f5fffc 70%,#fffaf0 100%);border:2px solid #d8eeeb;border-radius:22px}.expression-input{background:#ffffffc7;border:2px solid #cbe5e2;border-radius:13px;margin-top:9px;padding:12px 14px 13px;font-size:34px;transition:border-color .18s,box-shadow .18s}.expression-input:focus{border-color:#53bcb1;box-shadow:0 0 0 5px #159c921a}.example-row button{border-radius:999px;transition:transform .18s,background .18s}.example-row button:hover{background:#e8faf6;transform:translateY(-2px)}.tab-bar{background:#e6f2f5cc;border-radius:15px}.tab-bar button{border-radius:11px;transition:color .18s,background .18s,transform .18s}.tab-bar button:hover{color:var(--teal-dark);transform:translateY(-1px)}.tab-bar button.active{box-shadow:0 4px 10px #2a68731a}.conversation{background:#ffffffeb;border-radius:21px}.message p{background:#eef9f7;border-radius:5px 18px 18px}.message.student p{background:#fff3d7;border-radius:18px 5px 18px 18px}.avatar{width:31px;height:31px;font-size:13px;box-shadow:0 3px #00000014}.answer-row input{border-radius:12px}.primary-button,.secondary-button{border-radius:12px;transition:transform .18s,box-shadow .18s,background .18s}.primary-button{background:linear-gradient(135deg,#16a99b,#087f79);border:0;box-shadow:0 5px #08645f}.primary-button:hover{background:linear-gradient(135deg,#20b7a7,#08746f);transform:translateY(-2px);box-shadow:0 7px #08645f}.secondary-button{border-radius:12px}.secondary-button:hover{background:#e7faf6;transform:translateY(-2px)}.insight-card{background:#ffffffe6;border-radius:18px}.progress-track{background:#e6f0f1;border-radius:999px;height:8px}.progress-track span{border-radius:inherit;background:linear-gradient(90deg,#ffc857,#16a99b)}.practice-flow{background:#fffc;border-radius:18px}.practice-flow button{border-radius:13px;transition:transform .18s,box-shadow .18s,background .18s}.practice-flow button:not(:disabled):hover{transform:translateY(-2px);box-shadow:0 5px 10px #2a687314}.practice-flow button.active{box-shadow:inset 0 -3px #159c92}.knowledge-lesson{background:linear-gradient(135deg,#fff 0%,#f6fffc 72%,#fff8df 100%);border-radius:21px}.guide-block,.guide-example,.guide-visual,.guide-pitfall{border-radius:0 13px 13px 0}.lesson-topics strong{border-radius:999px}.chapter-question{border-radius:18px;transition:transform .18s,box-shadow .18s}.chapter-question:hover{transform:translateY(-2px);box-shadow:0 14px 28px #2a68731a}.option-list button{border-radius:12px;transition:transform .18s,border-color .18s,background .18s}.option-list button:hover,.option-list button.selected{transform:translateY(-2px)}.chapter-answer{border-radius:12px}.hint-button{background:#edf9f6;border-radius:999px;padding:7px 11px}.hint-button:hover:not(:disabled){background:#dcf5ef}.question-hint,.stage-summary,.chapter-feedback{border-radius:12px}.extension-card,.selected-extension{border-radius:18px}.quick-link{border-radius:10px;padding-left:9px;padding-right:9px;transition:background .18s,padding .18s}.quick-link:hover{background:#f1faf8;padding-left:13px}body{font-size:15px}.topbar h1{font-size:28px}.brand-subtitle{font-size:13px}.topbar-meta{font-size:14px}.streak-badge{font-size:13px}.section-kicker,.eyebrow{font-size:12px}.panel-heading h2,.lesson-header h2{font-size:27px}.chapter-item{padding:15px 11px}.chapter-item strong{font-size:16px}.chapter-item small{font-size:13px;line-height:1.6}.chapter-number{font-size:13px}.sidebar-note p{font-size:14px}.book-tag,.pill,.result-badge{padding:6px 10px;font-size:12px}.topic-select-wrap label,.input-label{font-size:14px}.topic-select-wrap select{font-size:15px}.muted{font-size:13px}.expression-input{font-size:40px}.example-row{font-size:13px}.example-row button{padding:7px 11px;font-size:13px}.conversation-header h3{font-size:23px}.step-counter{font-size:13px}.message p{font-size:16px;line-height:1.8}.message.error p{color:#b43f2b;background:#fff0eb;border:2px solid #f2a08d;font-weight:700}.message.error .avatar{background:#e4573d}.message.success p{color:#267448;background:#effbf2;border:2px solid #9cdbb3;font-weight:700}.message.success .avatar{background:#39a866}.answer-row input{font-size:16px}.primary-button,.secondary-button{padding:13px 17px;font-size:14px}.tab-bar button{padding:12px 9px;font-size:14px}.insight-copy{font-size:15px}.progress-label,.history-item{font-size:13px}.analysis-hero h3,.stage-heading h3{font-size:22px}.analysis-hero p:not(.section-kicker){font-size:13px}.practice-flow button small{font-size:12px}.practice-flow button em{font-size:11px}.practice-flow button strong{font-size:16px}.knowledge-lesson h3{font-size:25px}.lesson-text{font-size:16px}.guide-block,.guide-example,.guide-visual,.guide-pitfall{font-size:14px;line-height:1.8}.guide-block strong,.guide-example strong,.guide-visual strong,.guide-pitfall strong,.lesson-topics,.lesson-topics strong{font-size:13px}.chapter-question h3{font-size:20px;line-height:1.75}.question-meta .section-kicker{font-size:13px}.option-list button{padding:13px;font-size:15px}.chapter-answer{font-size:16px}.hint-button{font-size:14px}.question-hint,.stage-summary,.chapter-feedback{font-size:14px;line-height:1.75}.stage-tip{font-size:13px}.feature-card,.selected-extension{font-size:14px}.step-list,.pitfall-list{font-size:14px;line-height:1.8}.extension-title,.extension-card small{font-size:12px}.extension-card strong{font-size:18px}.quick-link,.summary-copy,.insight-list{font-size:14px}.workspace{background:linear-gradient(135deg,#d8f3fab8,#eefaf2bd 54%,#fff2d3a3);border:1px solid #4a9aa524;border-radius:31px;padding:18px;position:relative;box-shadow:0 18px 40px #2d6f7b1a}.topic-focus-card{background:linear-gradient(110deg,#f8fffd,#fffaf0);border:2px solid #d9ece9;border-radius:19px;align-items:center;gap:14px;margin-bottom:14px;padding:16px 19px;display:flex}.topic-focus-icon{color:#ad7511;background:#fff0bd;border-radius:14px;flex:none;place-items:center;width:43px;height:43px;font-size:28px;font-weight:800;display:grid}.topic-focus-copy{flex:1;min-width:0}.topic-focus-copy h3{color:var(--teal-dark);margin:3px 0;font-size:20px}.topic-focus-copy p{color:#405b65;margin:0;font-size:13px;line-height:1.55}.topic-focus-copy small,.topic-focus-copy em{color:var(--muted);margin-top:3px;font-size:12px;font-style:normal;line-height:1.5;display:block}.topic-focus-copy em{color:#a36f19}.topic-focus-card .secondary-button{white-space:nowrap}.topic-focus-card .secondary-button span{margin-left:4px;font-size:17px}.insight-method{color:#55717a;margin:-8px 0 16px;font-size:13px;line-height:1.65}.question-visual{background:linear-gradient(105deg,#f1fbfa,#fffaf0);border-radius:15px;min-height:126px;margin:13px 0 5px;padding:7px 10px 9px;position:relative;overflow:hidden}.question-visual svg{width:100%;height:112px;display:block}.visual-label{color:#718391;background:#ffffffbf;border-radius:999px;padding:3px 8px;font-size:10px;font-weight:700;position:absolute;top:8px;right:11px}.time-visual{background:linear-gradient(105deg,#eafaf7,#fff7dd)}.length-visual{background:linear-gradient(105deg,#fff8db,#f4fbff)}.transform-visual{background:linear-gradient(105deg,#f0f9ff,#f8f0ff)}.observe-visual{background:linear-gradient(105deg,#f1f9ff,#fff7e8)}.interval-visual,.relationship-visual,.groups-visual{background:linear-gradient(105deg,#effbf8,#f4f0ff)}.multiple-visual{background:linear-gradient(105deg,#f6f0ff,#fff6df)}.data-visual{background:linear-gradient(105deg,#fff8df,#eef9ff)}.answer-status{border:2px solid;border-radius:18px;align-items:center;gap:14px;padding:17px 20px;display:flex}.answer-status-icon{color:#fff;border-radius:50%;flex:none;place-items:center;width:42px;height:42px;font-size:28px;font-weight:800;line-height:1;display:grid}.answer-status strong{font-size:20px;display:block}.answer-status p{margin:4px 0 0;font-size:14px;line-height:1.6}.answer-status.correct{color:#267448;background:#effbf2;border-color:#9cdbb3}.answer-status.correct .answer-status-icon{background:#39a866}.answer-status.incorrect{color:#b84d36;background:#fff2ed;border-color:#f2a08d}.answer-status.incorrect .answer-status-icon{background:#e4573d}@media (width<=1100px){.workspace{grid-template-columns:220px minmax(0,1fr);gap:14px;width:calc(100% - 40px)}.insight-column{grid-column:1/-1;grid-template-columns:repeat(3,minmax(0,1fr))}.sidebar{min-height:0}}@media (width<=900px){.topbar{height:auto;min-height:94px;padding:14px 22px}.topbar-meta{flex-wrap:wrap;justify-content:flex-end}.workspace{border-radius:24px;grid-template-columns:minmax(0,1fr);width:calc(100% - 28px);margin-top:18px;padding:12px}.sidebar{padding:17px 14px}.chapter-list{grid-template-columns:repeat(2,minmax(0,1fr));max-height:275px;overflow:auto}.sidebar-note{margin-top:14px}.lesson-header{gap:12px}.insight-column{grid-column:auto;grid-template-columns:repeat(3,minmax(0,1fr))}.topic-focus-card{flex-wrap:wrap}.topic-focus-card .secondary-button{margin-left:57px}.practice-flow{grid-template-columns:repeat(3,minmax(0,1fr))}.practice-flow button:first-child{grid-column:span 3}.analysis-grid,.summary-grid{grid-template-columns:minmax(0,1fr)}.next-step-card{flex-direction:column}.ai-summary{width:100%;max-width:none}}@media (width<=620px){.topbar{flex-direction:column;align-items:flex-start;gap:12px;padding:14px 16px 17px}.topbar-meta{justify-content:flex-start;gap:10px;width:100%;font-size:13px}.topbar:after{display:none}.brand-mark{width:42px;height:42px}.topbar h1{font-size:23px}.streak-badge{font-size:12px}.workspace{border-radius:19px;gap:12px;width:calc(100% - 16px);margin:10px auto 24px;padding:8px}.panel-heading{padding-bottom:13px}.chapter-list{gap:5px;max-height:230px}.chapter-item{grid-template-columns:25px minmax(0,1fr);gap:6px;padding:9px 6px}.chapter-item strong{font-size:14px}.chapter-item small{font-size:12px}.lesson-header{flex-direction:column;align-items:flex-start;min-height:0;padding:4px 4px 12px}.lesson-header h2,.panel-heading h2{font-size:23px}.topic-select-wrap{justify-content:space-between;width:100%}.topic-select-wrap select{max-width:72%}.topic-focus-card{align-items:flex-start;gap:10px;padding:13px}.topic-focus-icon{width:36px;height:36px;font-size:23px}.topic-focus-copy{flex-basis:calc(100% - 48px)}.topic-focus-copy h3{font-size:18px}.topic-focus-card .secondary-button{margin-left:0}.problem-card{padding:15px}.expression-input{font-size:32px}.tab-bar{justify-content:flex-start;overflow-x:auto}.tab-bar button{flex:none;min-width:max-content;padding:11px 10px}.conversation{min-height:410px;padding:16px 14px}.answer-row{grid-template-columns:repeat(2,minmax(0,1fr))}.answer-row input{grid-column:1/-1}.answer-row button{min-width:0;padding:11px 8px}.insight-column,.option-list{grid-template-columns:minmax(0,1fr)}.analysis-hero{align-items:flex-start;gap:10px;padding:17px}.analysis-hero h3,.stage-heading h3{font-size:19px}.knowledge-lesson{padding:17px}.knowledge-lesson h3{font-size:21px}.chapter-question{padding:15px}.chapter-question h3{font-size:18px}.extension-grid{grid-template-columns:minmax(0,1fr)}.extension-answer-row{flex-wrap:wrap}.extension-answer-row input{flex-basis:100%}.answer-status{align-items:flex-start;padding:13px}.answer-status strong{font-size:17px}.feature-card{padding:16px}}
