:root{color-scheme:dark;--bg:#0a1020;--panel:#121b30;--panel2:#17233a;--line:#293750;--txt:#eaf0fc;--muted:#aab9d1;--teal:#63e6c4;--blue:#85b6ff;--amber:#ffcd75}*{box-sizing:border-box}body{margin:0;background:radial-gradient(circle at 85% -10%,#1b3150,transparent 42%),var(--bg);color:var(--txt);font:16px/1.7 system-ui,-apple-system,'Segoe UI',sans-serif}header{height:76px;border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;padding:0 max(22px,calc((100vw - 1450px)/2));gap:20px}#logo{color:var(--teal);font-size:24px;text-decoration:none;white-space:nowrap}#logo span{font-size:10px;letter-spacing:2px;color:var(--muted);margin-left:13px}.header-right{display:flex;gap:16px;align-items:center}.version{font-size:12px;letter-spacing:1px;color:var(--muted)}button{cursor:pointer;font:inherit}.smallbtn{background:transparent;color:var(--muted);border:1px solid var(--line);border-radius:10px;padding:6px 11px;font-size:12px}.shell{max-width:1450px;margin:auto;display:grid;grid-template-columns:318px minmax(0,1fr);min-height:calc(100vh - 140px)}aside{border-right:1px solid var(--line);padding:32px 22px}aside h2{margin:3px 0;font-size:25px}aside p,.aside-note{color:var(--muted);font-size:13px}.eyebrow{color:var(--teal);font-size:11px;letter-spacing:2px;font-weight:800}.progress{height:8px;border-radius:20px;background:#253249;margin-top:20px;overflow:hidden}.progress>div{height:100%;width:0;background:linear-gradient(90deg,#3db6b2,#72e9a9)}#progressText{display:block;margin:8px 0 25px;color:var(--muted)}.chapterlink{width:100%;text-align:left;border:1px solid transparent;background:transparent;border-radius:13px;padding:12px 10px;color:var(--txt);margin-bottom:5px}.chapterlink:hover,.chapterlink.active{background:#1a2a43;border-color:#35516a}.chapterlink strong{display:block;font-size:13px}.chapterlink span{display:block;color:var(--muted);font-size:12px}.aside-note{border-top:1px solid var(--line);margin-top:25px;padding-top:20px}main{padding:45px clamp(22px,5vw,85px) 90px;min-width:0;max-width:1100px;width:100%}.hero{padding:36px;border:1px solid #31516a;border-radius:24px;background:linear-gradient(120deg,#172e46,#132038 65%)}h1{font-size:clamp(28px,3vw,44px);line-height:1.22;margin:10px 0 16px;letter-spacing:-.8px}h2{line-height:1.35}p{margin:10px 0}.lead{color:#c6d6e8;font-size:18px}.stats{display:flex;flex-wrap:wrap;gap:10px;margin:24px 0}.stat{background:#20364e;border:1px solid #37516b;border-radius:12px;padding:9px 14px;font-size:13px}.stat b{color:var(--teal)}.btn{border:0;border-radius:12px;padding:12px 19px;background:var(--teal);color:#062c32;font-weight:750}.btn.alt{background:#243850;color:var(--txt);border:1px solid #3c5670}.btn:disabled{opacity:.45;cursor:not-allowed}.chaptercards{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:15px;margin-top:28px}.chaptercard{padding:22px;border-radius:17px;background:var(--panel);border:1px solid var(--line);text-align:left;color:var(--txt)}.chaptercard:hover{border-color:var(--teal)}.chaptercard h3{margin:8px 0}.chaptercard p{font-size:14px;color:var(--muted)}.pill{display:inline-block;background:#213c4c;color:var(--teal);font-size:11px;font-weight:800;border-radius:20px;padding:3px 10px}.pill.deep{background:#342b50;color:#d6b5ff}.back{background:transparent;border:0;color:var(--blue);padding:0;margin-bottom:18px}.lessonlist{display:grid;gap:10px;margin-top:26px}.lessonlink{display:flex;gap:15px;align-items:center;width:100%;padding:18px 20px;background:var(--panel);border:1px solid var(--line);border-radius:14px;text-align:left;color:var(--txt)}.lessonlink:hover{border-color:var(--blue)}.num{color:var(--teal);font-size:13px;font-weight:800;min-width:50px}.lessonlink strong{display:block}.lessonlink small{color:var(--muted)}.done{margin-left:auto;color:var(--teal)}.section{margin-top:30px;padding:25px 28px;background:var(--panel);border:1px solid var(--line);border-radius:18px}.section h2{margin:0 0 12px;font-size:21px}.section p{color:#d5e0ef;line-height:1.85}.section small{color:var(--teal);font-size:11px;letter-spacing:1.5px;font-weight:700}.figure{padding:18px;border-radius:18px;background:#0f1b2e;border:1px solid #344762;margin:25px 0}.figure svg{display:block;width:100%;height:auto;max-height:280px}.figure figcaption{color:var(--muted);font-size:13px;margin-top:8px}.callout{padding:18px 22px;border-left:3px solid var(--amber);background:#282738;border-radius:0 12px 12px 0;margin-top:20px}.callout.good{border-color:var(--teal);background:#17333c}.callout strong{display:block;margin-bottom:5px}.callout p{font-size:15px;margin:0}.choice{display:block;width:100%;text-align:left;background:#182842;border:1px solid #34465e;color:var(--txt);padding:12px 16px;border-radius:11px;margin:10px 0}.choice:hover{border-color:var(--blue)}.choice.selected{border-color:var(--teal);background:#194441}.choice.wrong{border-color:#ff8d8d;background:#492a3c}.feedback{margin:16px 0;padding:16px;border-radius:12px;background:#1c3741;color:#e5f8f3}.actions{display:flex;gap:12px;flex-wrap:wrap;margin-top:26px}.assessment{margin-top:25px;border:1px solid #567451;background:linear-gradient(120deg,#1b3a3b,#1d293a);border-radius:16px;padding:25px}.examitem{margin:20px 0;padding:18px;background:var(--panel);border:1px solid var(--line);border-radius:14px}.examitem h3{font-size:16px;margin:0 0 12px}.examitem label{display:block;padding:7px 0;cursor:pointer}.examresult{padding:20px;background:#1b3b40;border-radius:14px;margin:20px 0}.muted{color:var(--muted)}footer{border-top:1px solid var(--line);padding:18px;text-align:center;color:var(--muted);font-size:12px}a{color:var(--blue)}@media(max-width:850px){.shell{grid-template-columns:1fr}aside{border-right:0;border-bottom:1px solid var(--line);padding:22px}#sidebar{display:grid;grid-template-columns:repeat(2,1fr);gap:4px}main{padding:28px 18px 70px}.chaptercards{grid-template-columns:1fr}.hero{padding:25px}.version{display:none}header{padding:0 16px}#logo span{display:none}.section{padding:20px}}

.choice.correct{border-color:#38d9ac!important;background:#153e36!important}.choice.wrong{border-color:#ff7f7f!important;background:#442b37!important}.hintbox,.glossary{border:1px solid #527c8a;background:#142d3b;border-radius:14px;padding:16px;margin:16px 0}.hintbox li{margin:10px 0}.glossary summary{cursor:pointer;font-weight:700}.glossary p{line-height:1.65}.choice:disabled{cursor:default;opacity:1}.btn:disabled{opacity:.5;cursor:not-allowed}

.worked-solution h3{margin:18px 0 8px;font-size:1.05rem}.worked-solution h3:first-child{margin-top:0}.worked-solution li{margin-bottom:10px}.worked-solution p{line-height:1.75}.worked-solution p strong{color:#a9e9e1}

.quickitem{border:1px solid rgba(150,175,200,.27);border-radius:14px;padding:20px;margin:18px 0}.quickitem h3{margin:10px 0 16px}.quickopts{display:grid;gap:8px}.quickitem .feedback:empty{display:none}

/* v0.9: one unified core knowledge block and explicit application question */
.knowledge-unified{padding:24px;border:1px solid var(--line, #39465d);border-radius:18px;background:rgba(112,137,180,.045)}
.knowledge-unified .knowledge-part{padding:17px 0;border-bottom:1px solid rgba(140,160,190,.18)}
.knowledge-unified .knowledge-part:last-of-type{border-bottom:0}
.knowledge-unified .knowledge-part h3{margin:0 0 10px;font-size:1.08rem}
.knowledge-unified .figure{margin:20px 0 0}
.practice-question{padding:15px 18px;border-left:3px solid #60a5fa;background:rgba(96,165,250,.09);border-radius:8px}

/* World 1 v1.0: readable situation and question */
.example-practice .scenario{border:1px solid #3a5571;border-radius:16px;padding:20px;background:rgba(59,130,246,.06);margin:16px 0}.scenario-label{font-weight:800;color:#9ddaff;margin:14px 0 5px}.scenario-label:first-child{margin-top:0}.scenario p{line-height:1.8;margin:4px 0 12px}.scenario .practice-question{font-weight:650;color:#f2f8ff}.example-practice h2,.knowledge-unified h2{line-height:1.35}.worked-solution h3{margin-top:14px}.worked-solution p{line-height:1.85}