:root{--ink:#173c48;--muted:#5b6b70;--paper:#f7f5ed;--yellow:#f2cc65;--line:#d8ddd5;--soft:#e8ede6;--blue:#23566a;--white:#fffef9;--orange:#b64e31}*{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:var(--paper);color:var(--ink);font:16px/1.75 -apple-system,BlinkMacSystemFont,"Segoe UI","PingFang HK",sans-serif}a{color:inherit;text-underline-offset:4px}button,input,select,textarea{font:inherit}button,.button{cursor:pointer}button,.button{display:inline-flex;align-items:center;justify-content:center;gap:8px;min-height:44px;border:1px solid var(--line);border-radius:8px;padding:9px 16px;background:var(--white);color:var(--ink);text-decoration:none}button:hover,.button:hover{border-color:var(--blue);background:#edf0e8}.primary{background:var(--yellow);border-color:var(--yellow);font-weight:650}.dark{background:var(--ink);color:var(--white)}:focus-visible{outline:3px solid var(--orange);outline-offset:4px}h1,h2,h3{font-family:Georgia,"Songti TC",serif;font-weight:500;line-height:1.13;margin:0 0 20px}h1{font-size:clamp(42px,5.5vw,76px);letter-spacing:-2px}h2{font-size:clamp(29px,3.2vw,43px);letter-spacing:-.7px}h3{font-size:25px}p{margin:0 0 20px}.wrap{width:min(1240px,calc(100% - 64px));margin:auto}.bar{display:flex;align-items:center;justify-content:space-between;gap:24px;min-height:91px}.brand{text-decoration:none;display:flex;gap:12px;align-items:center;font-family:Georgia,serif;font-size:22px;line-height:1.2}.brand img{width:38px;height:38px}.brand small{font:9px/1.4 sans-serif;letter-spacing:2px;display:block;margin-top:6px;text-transform:uppercase}.nav{display:flex;gap:23px;align-items:center}.nav a{font-size:14px;text-decoration:none}.nav a[aria-current=page]{text-decoration:underline;text-decoration-color:var(--orange)}.lang{font-size:13px;border-color:#b8c6c9;background:transparent}header{border-bottom:1px solid var(--line)}.eyebrow{text-transform:uppercase;font-size:11px;font-weight:700;letter-spacing:2px;line-height:1.6;margin-bottom:20px;color:var(--blue)}.hero{display:grid;grid-template-columns:1fr 1fr;gap:50px;align-items:center;padding:56px 0 46px}.hero .lead{font-size:18px;max-width:530px;color:var(--muted)}.hero h1 em{font-style:italic;color:var(--blue)}.hero-art{position:relative;align-self:stretch;min-height:460px;border-radius:12px;overflow:hidden;background:var(--ink)}.hero-art img{width:100%;height:100%;position:absolute;object-fit:cover}.art-caption{position:absolute;bottom:14px;left:16px;color:#fff;background:#153c49de;padding:5px 10px;border-radius:5px;font-size:10px;letter-spacing:.6px}.actions{display:flex;gap:12px;flex-wrap:wrap;margin:26px 0}.statbar{border-top:1px solid var(--line);border-bottom:1px solid var(--line);display:grid;grid-template-columns:repeat(4,1fr);padding:19px 0;gap:18px;font-size:13px}.statbar strong{display:block;font-family:Georgia,serif;font-size:25px;line-height:1.4}.section{padding:56px 0}.section-title{display:flex;align-items:end;justify-content:space-between;gap:24px;margin-bottom:25px}.section-title p{color:var(--muted);max-width:460px;margin:0}.grid{display:grid;grid-template-columns:repeat(3,1fr);gap:23px}.card{background:var(--white);border:1px solid var(--line);border-radius:12px;overflow:hidden;position:relative;transition:transform .2s}.card:hover{transform:translateY(-3px)}.card>a{text-decoration:none;display:block}.card img{width:100%;height:170px;object-fit:cover;display:block;background:#e2e9e5}.card-body{padding:23px}.card .eyebrow{margin-bottom:11px;font-size:10px}.card h3{font-size:25px;margin-bottom:12px}.card p{font-size:14px;line-height:1.6;color:var(--muted);margin-bottom:16px}.card-bottom{display:flex;justify-content:space-between;align-items:center;font-size:12px}.card-bottom button{padding:3px 10px;font-size:18px;min-height:38px}.spotlight{display:grid;grid-template-columns:.8fr 1.2fr;gap:44px;background:var(--ink);color:var(--paper);padding:42px;border-radius:14px;align-items:center}.spotlight .eyebrow{color:var(--yellow)}.spotlight p{color:#d1dee0}.spotlight img{width:100%;border-radius:10px}.spotlight h2{font-size:38px}.tools{display:flex;gap:13px;flex-wrap:wrap;margin:26px 0}.tools input{flex:1;min-width:180px}input,select,textarea{background:var(--white);border:1px solid #acbec1;padding:11px 13px;color:var(--ink);border-radius:7px}input[type=range]{padding:0;width:100%;accent-color:var(--blue)}.pagehead{padding:48px 0 30px}.pagehead h1{font-size:clamp(37px,4.5vw,60px)}.pagehead .lead{max-width:760px;font-size:19px;color:var(--muted)}.read-layout{display:grid;grid-template-columns:230px minmax(0,790px);gap:60px;justify-content:center;padding-bottom:70px}.sidebar{font-size:13px}.sidebar-inner{position:sticky;top:24px}.sidebar a{display:block;padding:9px 0;text-decoration:none;border-bottom:1px solid var(--line);line-height:1.5}.sidebar a.active{font-weight:750;color:var(--orange)}.article{min-width:0;font-size:18px;line-height:1.92}.article h2{font-size:33px;margin:40px 0 21px;scroll-margin-top:25px}.article h3{font-size:24px;margin:29px 0 17px}.article p{margin-bottom:23px}.article .banner{width:100%;height:290px;object-fit:cover;border-radius:12px}.small,.source{font-size:13px;line-height:1.65;color:var(--muted)}.source{border-left:3px solid var(--yellow);padding:12px 17px;background:#fffdf6;margin:20px 0}.source a{overflow-wrap:anywhere}.note{background:var(--soft);border-radius:9px;padding:21px 24px;font-size:16px;margin:25px 0}.exercise{border:1px solid #a9bec0;border-radius:12px;padding:26px;margin:27px 0;background:#f0f4ed}.exercise h3{margin-top:0}.choices{display:grid;gap:10px}.choices button{text-align:left;justify-content:flex-start;line-height:1.5}.feedback{font-size:16px;margin-top:15px;border-left:3px solid var(--orange);padding-left:15px}.feedback:empty{display:none}details{border:1px solid var(--line);background:var(--white);border-radius:8px;padding:16px 20px;margin:12px 0;font-size:16px}summary{cursor:pointer;font-weight:600}details p{margin:15px 0 0!important}textarea{width:100%;min-height:150px;font-size:16px;resize:vertical}.lesson-actions{display:flex;gap:10px;flex-wrap:wrap;align-items:center;margin:22px 0}.prevnext{display:flex;justify-content:space-between;gap:15px;border-top:1px solid var(--line);padding-top:25px;margin-top:35px;font-size:15px}.narrow{max-width:820px}.lab-layout{display:grid;grid-template-columns:1fr 1fr;gap:40px;align-items:start}.panel{padding:30px;border:1px solid var(--line);border-radius:12px;background:var(--white)}.field{display:block;margin-bottom:22px}.field span{display:flex;justify-content:space-between;gap:15px}.result{background:var(--ink);color:var(--white);padding:30px;border-radius:12px}.result strong{font-family:Georgia,serif;font-size:53px;display:block;line-height:1.3}.result small{color:#d1dee0}.bars{display:grid;gap:20px;margin:30px 0}.bartrack{height:20px;background:#dde4de;border-radius:3px;overflow:hidden}.barfill{height:100%;background:var(--blue);min-width:0}.negative{background:var(--orange)}table{border-collapse:collapse;width:100%;font-size:14px}td,th{padding:9px;text-align:left;border-bottom:1px solid var(--line)}.tablewrap{overflow-x:auto}footer{border-top:1px solid var(--line);padding:28px 0;font-size:12px;color:var(--muted)}footer .wrap{display:flex;justify-content:space-between;gap:24px}.skip{position:absolute;top:-100px;z-index:10;background:var(--yellow);padding:12px}.skip:focus{top:5px}#storage:not(:empty){background:#fce9b2;padding:10px;text-align:center;font-size:14px}.empty{padding:35px;border:1px dashed var(--line);grid-column:1/-1}.meter{height:4px;background:var(--line);margin:18px 0}.meter span{display:block;background:var(--orange);height:100%}.chip{font-size:11px;border:1px solid var(--line);border-radius:100px;padding:4px 10px}.map{display:flex;align-items:center;justify-content:space-around;gap:12px;margin:23px 0;padding:22px 15px;background:#e9eee8;border-radius:9px;font-size:14px;text-align:center}.map span{flex:1}.map b{color:var(--orange)}[hidden]{display:none!important}@media(max-width:1000px){.nav{gap:14px}.brand{font-size:19px}.hero{gap:28px}.hero-art{min-height:390px}.read-layout{grid-template-columns:180px minmax(0,1fr);gap:30px}.grid{grid-template-columns:repeat(2,1fr)}}@media(max-width:720px){.wrap{width:calc(100% - 36px)}.bar{flex-wrap:wrap;gap:18px;padding:19px 0}.brand{flex:1}.nav{order:3;width:100%;justify-content:space-between;overflow:auto;gap:20px}.nav a{white-space:nowrap;font-size:13px}.lang{font-size:11px;padding:6px 9px}.hero{grid-template-columns:1fr;padding-top:35px;gap:20px}.hero h1{font-size:48px}.hero-art{height:280px;min-height:0}.statbar{grid-template-columns:1fr 1fr;gap:16px}.statbar strong{font-size:22px}.grid{grid-template-columns:1fr}.section{padding:35px 0}.section-title{display:block}.section-title p{margin-top:14px}.card img{height:200px}.spotlight{grid-template-columns:1fr;padding:25px;gap:25px}.spotlight h2{font-size:32px}.read-layout{display:block}.sidebar{margin-bottom:28px}.sidebar-inner{position:static}.sidebar details{font-size:14px}.article{font-size:17px;line-height:1.9}.article .banner{height:220px}.lab-layout{grid-template-columns:1fr;gap:23px}.panel,.result{padding:22px}.pagehead{padding-top:34px}.pagehead h1{letter-spacing:-1px}.exercise{padding:20px}.map{font-size:12px;padding:17px 10px;gap:8px}footer .wrap{display:block}.tools button{font-size:13px}.prevnext a{max-width:47%}}@media(prefers-reduced-motion:reduce){*{scroll-behavior:auto!important;transition:none!important}}@media print{header,footer,.sidebar,.choices,.lesson-actions,.prevnext,.tools,.skip{display:none!important}.wrap{width:100%}.read-layout{display:block}.article{font-size:11pt}.banner{max-height:150px}details>p{display:block!important}details{break-inside:avoid}.exercise{break-inside:avoid}textarea{height:100px}.hero-art{min-height:200px}.grid{grid-template-columns:1fr 1fr}}
@media(min-width:721px) and (max-width:1000px){.bar{flex-wrap:wrap;padding:18px 0;gap:18px}.brand{flex:1}.nav{order:3;width:100%;justify-content:space-between}.nav a,.lang{white-space:nowrap}}
#main:focus{outline:none}

.practice-games{margin:32px 0 48px;padding:clamp(20px,4vw,40px);background:var(--white);border:2px solid var(--line);border-radius:16px}.practice-games h2{margin-top:0}.game-tabs,.game-choices{display:flex;gap:12px;flex-wrap:wrap;margin:20px 0}.game-choices{display:grid;grid-template-columns:1fr}.game-choices button{text-align:left;justify-content:flex-start;white-space:normal}.game-choices button:disabled{cursor:default;opacity:1}.game-choices button[aria-pressed=true],.game-tabs button[aria-pressed=true]{background:var(--ink);color:var(--white)}.game-board{border-top:1px solid var(--line);padding-top:20px}.game-progress{font-size:14px}.game-feedback:not(:empty){padding:20px;background:var(--paper);border-left:4px solid var(--ink);margin-bottom:20px}.practice-invite{padding:18px 24px;border-left:5px solid var(--ink);background:var(--white);display:flex;justify-content:space-between;gap:12px;flex-wrap:wrap}.practice-games details{padding:15px 0;border-bottom:1px solid var(--line)}.practice-games summary{cursor:pointer}.practice-games details p{margin:12px 0}.practice-games h3{font-size:clamp(23px,3vw,30px)}@media print{.practice-games,.practice-invite{display:none}}

:root{--paper:#eef5ff;--ink:#142e66;--muted:#4a6188;--yellow:#b7d8ff;--line:#b7cbea;--soft:#dceaff;--blue:#2455b5;--white:#fbfdff;--orange:#2455b5}button:hover,.button:hover{background:#dceaff}.art-caption{background:#142e66e8}.card img{background:#dceaff}header{background:#e4efff}.exercise,.panel{background:var(--soft)}

body .capital-library-nav{background:#142e66;color:#fbfdff}