:root{--ink:#203c40;--muted:#657372;--paper:#f8f7f2;--white:#fffefa;--line:#dfE3da;--sea:#183e43;--mint:#e6eee7;--copper:#965b36;--serif:Georgia,'Times New Roman',serif;--sans:Inter,'Segoe UI',Arial,sans-serif}*{box-sizing:border-box}body{margin:0;background:var(--paper);color:var(--ink);font:15px/1.6 var(--sans)}a{color:inherit}button,select{font:inherit}button,a,select{touch-action:manipulation}button{cursor:pointer}button:focus-visible,a:focus-visible,select:focus-visible,summary:focus-visible{outline:3px solid #b16d40;outline-offset:5px}h1,h2,h3,p{margin-top:0}h1,h2,h3{line-height:1.15}h1{font:normal clamp(38px,4.6vw,66px)/1.06 var(--serif);letter-spacing:-2px;margin-bottom:22px}h2{font:normal 30px/1.2 var(--serif);letter-spacing:-.5px}h3{font-size:17px;font-weight:600}button{color:inherit}.site-header{height:94px;border-bottom:1px solid var(--line);display:flex;align-items:center;justify-content:space-between;padding:0 44px;gap:20px;background:var(--white)}.brand{display:flex;align-items:center;gap:12px;text-decoration:none;font-size:25px;font-weight:650;letter-spacing:-1px;line-height:1.1}.brand-light{font-weight:350}.brand small{display:block;font-size:10px;letter-spacing:1.6px;font-weight:400;margin-top:7px}.header-tools{display:flex;align-items:center;gap:24px}.edition,.eyebrow,.nav-label,.tiny-label{font-size:10px;letter-spacing:1.8px;text-transform:uppercase;font-weight:650}.edition{color:var(--copper);border:1px solid #ddc7b2;border-radius:30px;padding:5px 12px}.language select{border:0;border-left:1px solid var(--line);padding:6px 10px 6px 20px;background:transparent;color:var(--ink)}.app-shell{display:grid;grid-template-columns:218px minmax(0,1fr);max-width:1600px;margin:auto;min-height:calc(100vh - 170px)}.sidebar{border-right:1px solid var(--line);padding:35px 20px;display:flex;flex-direction:column}.nav-label{padding:0 15px;color:var(--muted);margin-bottom:16px}nav{display:grid;gap:6px}.nav-link{display:flex;gap:15px;align-items:center;text-decoration:none;padding:10px 15px;border-radius:5px;color:var(--muted);font-size:14px}.nav-link[aria-current=page]{background:var(--sea);color:#fff}.nav-icon{width:21px;font-size:18px;line-height:1;text-align:center}.sidebar-note{margin-top:110px;padding:24px 15px 0;border-top:1px solid var(--line);color:var(--muted);font:italic 17px/1.5 var(--serif)}.sidebar-note p{margin:10px 0 20px}.little-mark{font-size:35px;color:var(--copper)}.tiny-label{font:9px var(--sans);letter-spacing:2px}main{padding:35px 44px 50px;min-width:0}.page-top{display:flex;justify-content:space-between;gap:16px;align-items:center;margin-bottom:28px}.eyebrow{color:var(--copper)}.demo-tag{font-size:11px;color:var(--muted);display:flex;align-items:center;gap:8px}.demo-tag:before{content:'';width:6px;height:6px;border-radius:50%;background:#8d9f82}.hero{display:grid;grid-template-columns:1.05fr 1fr;background:#eaf0e9;border:1px solid #dce5d9;position:relative;overflow:hidden;min-height:345px}.hero-copy{padding:35px 15px 35px 35px;position:relative;z-index:1}.hero-copy>p{max-width:370px;color:#536b67;font-size:15px;margin-bottom:25px}.button{display:inline-flex;align-items:center;justify-content:center;gap:18px;border:1px solid var(--sea);background:var(--sea);color:var(--white);border-radius:4px;padding:10px 18px;text-decoration:none;font-size:13px;font-weight:600}.button:hover{background:#2c5559}.button.secondary{background:transparent;color:var(--ink);border-color:#b5c3b6}.hero-art{display:flex;flex-direction:column;justify-content:center;padding:30px 15px;position:relative}.hero-art:before{content:'';position:absolute;width:260px;height:260px;border:1px solid #cfdbcf;border-radius:50%;left:15%;top:10%;box-shadow:0 0 0 28px #e5ece2,0 0 0 29px #dbe5d7}.score{width:100%;height:auto;position:relative;color:var(--sea)}.art-caption{position:relative;text-align:center;font:italic 14px var(--serif);color:#5c7065;margin:10px 0 0}.section-head{display:flex;align-items:baseline;justify-content:space-between;gap:20px;margin:35px 0 18px}.section-head h2{margin:0;font-size:27px}.text-link{color:var(--copper);font-size:12px;text-underline-offset:4px}.today-grid{display:grid;grid-template-columns:minmax(0,1.6fr) minmax(220px,1fr);gap:20px}.lesson-card,.note-card,.topic-card,.panel{border:1px solid var(--line);background:var(--white);border-radius:5px}.lesson-card{display:grid;grid-template-columns:112px 1fr;overflow:hidden}.lesson-art{background:#e7ece1;display:flex;align-items:center;justify-content:center;font:60px var(--serif);color:var(--sea);border-right:1px solid var(--line)}.lesson-content{padding:23px}.meta{font-size:10px;text-transform:uppercase;letter-spacing:1.1px;color:var(--copper);margin-bottom:10px}.lesson-content h3{font:25px var(--serif);margin-bottom:10px}.lesson-content p,.note-card p,.topic-card p{font-size:13px;color:var(--muted)}.note-card{padding:23px;background:#f1eee5}.note-card h3{font:22px var(--serif);margin:9px 0}.note-card .text-link{display:inline-block;margin-top:5px}.topic-strip{display:grid;grid-template-columns:repeat(3,1fr);gap:15px}.topic-preview{border-top:1px solid var(--line);padding:17px 0;display:flex;gap:14px;text-decoration:none}.topic-preview>span{font:26px var(--serif);color:var(--copper)}.topic-preview h3{font-size:14px;margin:2px 0 5px}.topic-preview p{font-size:12px;color:var(--muted);margin:0}.scope-note{font-size:12px;color:var(--muted);padding-top:20px;border-top:1px solid var(--line);margin-top:20px}.page-title{max-width:780px;margin-bottom:30px}.page-title h1{font-size:46px;letter-spacing:-1px;margin-bottom:15px}.page-title p{color:var(--muted);max-width:660px}.panel{padding:28px;margin-bottom:22px}.panel h2{font-size:27px}.panel p:last-child{margin-bottom:0}.notice{padding:14px 18px;border-left:3px solid var(--copper);background:#f0ede3;font-size:13px;color:#645e50;margin-bottom:25px}.topic-grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:16px}.topic-card{padding:22px}.topic-num{font:italic 25px var(--serif);color:var(--copper);margin-bottom:22px}.topic-card h2{font-size:23px;margin-bottom:12px}.topic-card .meta{margin-top:20px;margin-bottom:0}.level-selector{display:flex;flex-wrap:wrap;gap:8px;margin:20px 0}.level-button{border:1px solid #bcc8bd;border-radius:4px;padding:9px 15px;background:transparent;font-size:13px}.level-button[aria-pressed=true]{background:var(--sea);color:white;border-color:var(--sea)}.route{display:grid;grid-template-columns:repeat(3,1fr);gap:15px;margin:24px 0}.route-step{border-top:2px solid #becfbf;padding:20px 0}.route-step span{font-size:12px;color:var(--copper)}.route-step h3{margin:10px 0}.route-step p{font-size:13px;color:var(--muted)}.lesson-score{max-width:540px;margin:20px auto;padding:15px;background:#f6f5ed}.lesson-score figcaption{font-size:12px;color:var(--muted);text-align:center}.concepts{display:grid;grid-template-columns:1fr 1fr;gap:25px}.concepts h3{font:23px var(--serif)}.concepts p{font-size:14px;color:var(--muted)}details{border-top:1px solid var(--line);padding:16px 0}summary{cursor:pointer;font-weight:600;padding-right:10px}details p{margin:12px 0 0;color:var(--muted);font-size:14px}.empty-state{display:flex;gap:25px;align-items:flex-start}.empty-icon{font-size:36px;color:var(--copper);line-height:1.2}.empty-state h2{margin-bottom:12px}.empty-state p{color:var(--muted);max-width:640px}.feature-list{padding-left:20px;color:var(--muted);font-size:14px}.feature-list li{margin:10px 0}footer{border-top:1px solid var(--line);padding:20px 44px;display:flex;justify-content:space-between;gap:20px;font-size:11px;color:var(--muted)}.skip-link{position:absolute;top:-90px;left:15px;z-index:10;background:white;padding:10px}.skip-link:focus{top:10px}.sr-only{position:absolute;width:1px;height:1px;padding:0;margin:-1px;overflow:hidden;clip:rect(0,0,0,0);white-space:nowrap;border:0}@media(min-width:1400px){main{padding:40px 65px}.hero-copy{padding:45px}.hero{min-height:390px}}@media(max-width:1100px){.app-shell{grid-template-columns:180px minmax(0,1fr)}main{padding:28px}.site-header{padding:0 28px}.hero-copy{padding:28px 12px 28px 28px}h1{font-size:45px}.today-grid{grid-template-columns:1fr}.topic-grid{grid-template-columns:repeat(2,minmax(0,1fr))}.sidebar{padding:30px 12px}.hero-art{padding:15px 5px}.hero-art:before{width:200px;height:200px}}@media(max-width:760px){.site-header{height:80px;padding:0 20px}.brand{font-size:22px}.brand img{width:35px;height:35px}.edition{display:none}.header-tools{gap:0}.language select{padding:5px;font-size:13px;border:0}.app-shell{display:block}.sidebar{padding:12px 16px;border-right:0;border-bottom:1px solid var(--line)}.nav-label,.sidebar-note{display:none}nav{display:grid;grid-template-columns:repeat(6,1fr);gap:3px}.nav-link{flex-direction:column;gap:6px;padding:9px 3px;font-size:10px}.nav-icon{font-size:18px}main{padding:25px 20px 35px}.page-top{margin-bottom:20px}.eyebrow{font-size:9px;letter-spacing:1.2px}.demo-tag{font-size:10px}.hero{grid-template-columns:1fr}.hero-copy{padding:28px 28px 10px}.hero-copy h1{max-width:450px;font-size:48px}.hero-copy>p{max-width:480px}.hero-art{padding:0 25px 25px}.hero-art .score{max-height:145px}.hero-art:before{width:180px;height:180px;top:-10%;left:30%;opacity:.7}.art-caption{font-size:12px;margin-top:0}.section-head{margin-top:28px}.section-head h2{font-size:25px}.today-grid{gap:14px}.lesson-card{grid-template-columns:78px 1fr}.lesson-content{padding:20px}.lesson-content h3{font-size:23px}.topic-strip{grid-template-columns:1fr}.topic-preview{padding:12px 0}.topic-preview p{font-size:13px}.section-head .text-link{font-size:11px}.page-title h1{font-size:38px}.topic-grid,.route,.concepts{grid-template-columns:1fr}.topic-card{padding:22px}.topic-num{float:right;margin-left:15px}.panel{padding:23px}.empty-state{gap:15px}.empty-icon{font-size:28px}.route-step{padding:15px 0}.route-step p{margin:0}footer{padding:20px;flex-wrap:wrap;gap:10px 20px}footer span:nth-child(2){width:100%;order:3}.scope-note{font-size:11px}}@media(prefers-reduced-motion:no-preference){a,button{transition:background .15s,color .15s}main{animation:appear .2s ease-out}@keyframes appear{from{opacity:.6;transform:translateY(3px)}to{opacity:1;transform:none}}}