/* Context: warm atlas surfaces, a consistent navigation, focused study. */
:root{--ink:#243830;--muted:#52634d;--green:#244f42;--paper:#fffef9;--line:#d4ddc9;--nav-height:76px;font-optical-sizing:auto}
html{background:#f6f4ed;color:var(--ink);font-family:system-ui,-apple-system,'Segoe UI',sans-serif}
button,a,input,textarea,summary{-webkit-tap-highlight-color:transparent}main:focus,.feedback:focus{outline:none}
a:focus-visible,button:focus-visible,input:focus-visible,textarea:focus-visible,summary:focus-visible{outline:3px solid #a15f26;outline-offset:4px}
.icon{display:block;width:24px;height:24px;fill:none;stroke:currentColor;stroke-width:1.8;stroke-linecap:round;stroke-linejoin:round;flex-shrink:0}
.icon-sprite{position:absolute;width:0;height:0;overflow:hidden}.skip-link{position:fixed;top:-100px;left:1rem;z-index:20;background:var(--green);color:white;padding:.75rem 1rem}.skip-link:focus{top:1rem}
.shell{grid-template-columns:240px minmax(0,1fr)}aside{padding:36px 20px;background:#efeee5;border-color:var(--line)}
.brand{gap:11px}.brand-icon{width:46px;height:46px;border-radius:15px;background:var(--green);color:#f7f0db;font:38px/1 Georgia,serif}.brand small{font:11px/1.4 system-ui,sans-serif;color:var(--muted)}
nav{gap:8px;margin-top:48px}nav a{gap:13px;padding:13px 14px;border-radius:14px;font-size:14px;color:#4e6148;min-height:52px}nav a.active{background:#dce6d4;color:#1f4b3c;font-weight:700}nav a.active:after{content:'';width:5px;height:5px;border-radius:50%;background:currentColor;margin-left:auto}.aside-note{color:var(--muted)}
nav a span{font-size:inherit;width:auto;text-align:inherit}
.workspace{padding:var(--tg-content-top,0px) 44px 0}header{height:auto;min-height:86px;gap:16px;color:var(--muted);font-size:12px;letter-spacing:0;border-color:var(--line)}.header-brand{display:flex;align-items:center;gap:10px}.header-brand .brand-icon{display:none}.header-title strong{display:block;font-weight:600;color:var(--ink)}.header-title small{font-size:11px}header>a{display:flex;gap:7px;align-items:center;min-height:44px;padding:0 9px;text-decoration:none;border-radius:12px}header>a .icon{width:20px;height:20px}header>a.active{background:#e4e9da;color:var(--green)}
main{margin:32px auto 52px}footer{color:var(--muted);font-size:12px;border-color:var(--line)}.eyebrow{font-size:11px;letter-spacing:.12em;color:#52664d;margin-bottom:10px}h1{font:40px/1.15 Georgia,serif;letter-spacing:-.025em;color:#203b30}h2{font:28px/1.25 Georgia,serif;letter-spacing:-.015em}h3{font:23px/1.3 Georgia,serif}.intro{max-width:650px;color:var(--muted);margin:14px 0 24px;line-height:1.65}.muted{color:var(--muted)}.page-heading{margin-bottom:24px}.page-heading .intro:last-child{margin-bottom:0}.page-heading h1{margin-bottom:0}
.home-heading{display:flex;justify-content:space-between;gap:24px;align-items:center}.home-heading h1{font-size:34px}.home-heading .intro{margin:8px 0 0;font-size:15px}.edition{flex-shrink:0;padding:8px 12px;border:1px solid #cdd5c2;border-radius:12px;font-size:12px;color:#52634c}
.hero{position:relative;overflow:hidden;background:var(--green);color:#fffbed;border-radius:24px;padding:28px 32px;margin:24px 0;grid-template-columns:minmax(0,1fr) 140px;gap:24px;box-shadow:0 10px 30px #244f4214}.hero:before{content:'';height:4px;position:absolute;left:32px;right:32px;top:0;background:#d4b47c;border-radius:0 0 4px 4px}.hero .eyebrow{color:#dbe5c6;letter-spacing:.12em}.hero h2{font-size:33px;max-width:560px}.hero p{color:#e2e8d8;max-width:560px;font-size:15px;line-height:1.65}.hero-cover{border:1px solid #ffffff2b;border-radius:80px 80px 12px 12px;display:flex;flex-direction:column;align-items:center;justify-content:center;position:relative;min-height:180px;background:linear-gradient(155deg,#ffffff0d,transparent)}.hero-cover:before,.hero-cover:after{content:'';position:absolute;inset:12px;border:1px solid #c7d3a62b;border-radius:70px 70px 8px 8px}.hero-cover:after{inset:24px}.hero-cover b{font:64px/1 Georgia,serif;color:#dfcea0}.hero-cover small{font-size:10px;letter-spacing:.18em;margin-top:10px;color:#e1e8cf}.hero-meta{display:flex;gap:9px;align-items:center;margin-bottom:18px;font-size:12px;color:#d9e5ca}.hero-meta .tag{border:1px solid #ffffff44;border-radius:20px;padding:3px 10px}
.learning-steps{display:flex;gap:0;list-style:none;margin:0 0 25px;padding:0;border:1px solid var(--line);background:#eeeede;border-radius:14px;overflow:hidden}.learning-steps li{flex:1;display:flex;align-items:center;justify-content:center;gap:9px;padding:10px 7px;font-size:13px;color:#4a604a}.learning-steps li+li{border-left:1px solid #d3dac8}.learning-steps span{font:17px Georgia,serif;color:#8a622f}
.btn{border-radius:13px;background:var(--green);border-color:var(--green);min-height:48px;font-size:15px;font-weight:650;line-height:1.5;padding:12px 18px}.btn.light{background:#f2efd8;color:#244b39}.btn.secondary{background:#fffef9;color:#315441;border-color:#bfcfb4}.btn.danger{color:#8b352a;border-color:#d9bcb1;background:#fcf4ee}.btn:active,.option:active{filter:brightness(.94)}.actions{gap:10px;margin-top:22px}.hero .btn{min-width:210px}.grid{gap:16px}
.card,.task-card{border:1px solid var(--line);background:var(--paper);border-radius:20px;padding:24px;box-shadow:0 3px 0 #24383003}.card p{font-size:15px}.card-top{display:flex;align-items:center;gap:12px;margin-bottom:15px}.card-top .eyebrow{margin:0}.icon-tile{width:42px;height:42px;border-radius:13px;background:#e6ecd9;color:#31533d;display:grid;place-items:center}.icon-tile.ochre{background:#f2e7ce;color:#845621}.section-head{margin:30px 0 16px}.text-link{display:inline-flex;align-items:center;min-height:44px;font-size:14px;font-weight:600;line-height:1.5;color:#31583e;text-decoration:underline;text-decoration-color:#829b6e;text-underline-offset:4px}.note{border:1px solid #e0d4b7;border-left:3px solid #b38443;background:#f2ecd9;padding:15px 18px;border-radius:4px 14px 14px 4px;font-size:14px;color:#604e30}.pill{border-radius:7px;font:600 12px/1.5 system-ui,sans-serif;background:#e6edda;color:#3f5c37;vertical-align:middle}.pill.pending{background:#eeeadf;color:#605b4e}.pill.due{background:#f3e2c6;color:#75481f}.row{border-color:#dfe4d6}.row p{color:#52634d;font-size:13px}.row strong{font-weight:650;line-height:1.5}.number{font:22px/1 Georgia,serif;color:#526644;min-width:38px;height:42px;display:grid;place-items:center;border:1px solid #d3dcc6;border-radius:12px;background:#edf0e4}.row-main{min-width:0}
.lesson-link{display:grid;grid-template-columns:38px minmax(0,1fr) 20px;text-decoration:none;min-height:88px;gap:13px}.lesson-link:hover .row-arrow{transform:translateX(3px)}.row-arrow{font-size:22px;color:#526e43;transition:transform .12s}.lesson-link .row-main{flex-basis:auto}.lesson-link .row-main p{line-height:1.8}
details.module{border:1px solid var(--line);background:#fffef9;border-radius:18px;margin:14px 0;overflow:hidden}summary{min-height:56px;color:#3e573e;font-size:14px;line-height:1.5}summary:after{content:'+';font:23px/1 system-ui,sans-serif;color:#496347}details.module>summary{padding:18px}.module-title{font-size:16px;font-weight:650;line-height:1.45}.module small{color:#52634d;font-size:12px;font-weight:400;margin-top:5px}.module .topics{padding:0 18px 18px}.topic{margin:0 0 18px;padding:20px 0 0;border-top:1px solid var(--line);font-size:15px}.topic>strong{display:block;margin-bottom:9px}.topic ul{margin:14px 0 0;padding-left:20px;color:#526047;font-size:14px;line-height:1.7}.topic li{margin:8px 0}.topic .row{padding:14px 0}.topic .text-link{padding:0 6px}.topic .pill{margin:0 0 3px}
.lesson{max-width:700px}.lesson h1{font-size:34px}.lesson .page-heading{margin-bottom:22px}.lesson-copy{font-size:18px;line-height:1.9;padding:24px;background:#fffef9;border:1px solid var(--line);border-radius:20px}.lesson-copy h2{margin-top:0;font-size:27px}.lesson-copy p:last-child{margin-bottom:0}.inquiry{margin:22px 0;background:#eeecd9;border:1px solid #dcd8be;border-radius:16px;padding:18px 20px}.inquiry:before{content:'?';float:right;font:40px/1 Georgia,serif;color:#9d7c40;margin:4px 0 10px 16px}.inquiry p{font-size:18px;line-height:1.55;font-weight:600;margin-bottom:10px}.inquiry small{font-size:14px;line-height:1.6;color:#565b43}.inquiry .eyebrow{color:#735b2d}.progress-track{height:6px;border-radius:6px;background:#dfe5d3;margin:20px 0 12px;overflow:hidden}.progress-track i{background:#5c7b49}.chain div{border-color:#d3ddc6;border-radius:14px;background:#f1f3e7;font-size:15px}.chain small{letter-spacing:.06em;font-size:11px;color:#526346;font-weight:700;margin-bottom:7px}
.question{font-size:21px;line-height:1.5}.skill{display:inline-flex;background:#e8eddf;border:1px solid #d4dfc7;border-radius:7px;padding:4px 9px;font-size:12px;color:#3e5c35;font-weight:650;margin-bottom:12px}.task-card{margin-top:0}.options{gap:10px}.option{position:relative;background:#fafbf4;border:1.5px solid #bccdaf;padding:14px 16px;border-radius:13px;min-height:54px;color:#2f412e;line-height:1.65;font-size:16px}.option.selected{background:#e4edda;border-color:#3e663a;box-shadow:inset 4px 0 #3e663a;padding:14px 16px}.option:disabled{opacity:1;color:#4b5a44}.option.is-answer{border-color:#426d39;background:#e6efdc}.option.is-mistake{border-color:#a06337;background:#f7e9dc}.answer-marker{display:block;font-size:12px;font-weight:700;margin-top:7px;color:#3f5d34}.option.is-mistake .answer-marker{color:#8a4d25}
.feedback{background:#edf1e3;border:1px solid #cbd9bc;border-left:4px solid #688351;border-radius:16px;line-height:1.7}.feedback.wrong{background:#f6ebdd;border-color:#ddc5a5;border-left-color:#a67437}.feedback h3:before{content:none}.feedback.answer-success h3:before{content:'✓ ';font-family:system-ui,sans-serif}.feedback.wrong h3:before{content:'↻ ';font-family:system-ui,sans-serif}.feedback .muted{color:#4f5c45}.recall,input[type=search]{border-color:#aabc9e;border-radius:13px;padding:15px;color:#243830;font-size:16px;line-height:1.7}.recall{min-height:160px;scroll-margin:24px 0 110px}.recall[readonly]{background:#efefe4;color:#4c5945}label{font-size:14px;font-weight:600;color:#42563d}input[type=file]{font-size:14px;line-height:1.7}input::file-selector-button{font:inherit;background:#e9eedf;border:1px solid #bdcbb0;border-radius:9px;padding:10px;margin:0 9px 8px 0;color:#31533d}.source-list{font-size:14px;color:#526346;padding-left:20px}.source-list li{margin-bottom:16px}.source-list a{display:inline-block;padding:8px 0;color:#31593c}.lesson details{border-top:1px solid var(--line)}.lesson summary{font-size:14px}
.timeline{border-color:#b7c79f;padding-left:22px;margin:26px 0 32px}.timeline article{margin-bottom:18px;padding:18px;border:1px solid var(--line);border-radius:16px;background:#fffef9}.timeline article:before{left:-28px;top:26px;width:10px;height:10px;background:#628047}.timeline strong{font:22px/1.3 Georgia,serif}.timeline p{font-size:15px;margin:10px 0 0}.timeline .text-link{font-size:13px}.empty{padding:24px;border:1px dashed #becbac;background:#f0f2e5;border-radius:16px;color:#4d6143;margin:20px 0}.search-summary{font-size:13px;color:#52634a;margin-top:12px}dt{font-weight:650;padding-top:16px;border-top:1px solid var(--line)}dd{color:#526147;font-size:16px}.exercise-timeline{background:#eff1e4;border:1px solid #d9dfc9;border-radius:14px}.exercise-timeline figcaption{font-size:14px;color:#445d38}.exercise-timeline p{font-size:13px;color:#4f6045}
#notice:not(:empty){background:#203f31;border-radius:14px;z-index:10;box-shadow:0 5px 20px #0002;font-size:14px}
@media(min-width:701px){aside{padding-top:calc(36px + var(--tg-content-top,0px))}}
@media(max-width:1000px) and (min-width:701px){.shell{grid-template-columns:200px minmax(0,1fr)}.workspace{padding-left:24px;padding-right:24px}aside{padding-left:14px;padding-right:14px}.brand{font-size:24px}.brand small{font-size:9px}.hero{grid-template-columns:1fr}.hero-cover{display:none}.home-heading .edition{display:none}}
@media(max-width:700px){
 :root{--nav-height:74px}.shell{display:block}aside{height:auto;position:fixed;top:auto;bottom:0;left:0;right:0;z-index:5;padding:7px max(8px,var(--tg-content-right,0px)) calc(7px + max(env(safe-area-inset-bottom),var(--tg-content-bottom,0px))) max(8px,var(--tg-content-left,0px));background:rgba(251,252,246,.98);border:0;border-top:1px solid #d1d9c5;box-shadow:0 -6px 22px #2438300c;backdrop-filter:blur(18px)}
 nav{display:grid;grid-template-columns:repeat(5,minmax(0,1fr));gap:4px;margin:0}nav a{display:flex;flex-direction:column;justify-content:center;gap:5px;font-size:10px;line-height:1.2;padding:8px 1px 7px;min-height:58px;border-radius:14px;text-align:center;white-space:nowrap;color:#4e614a}nav a .icon{width:23px;height:23px}nav a.active{background:#e1e9d5;color:#234f38}nav a.active:after{display:none}
 .workspace{padding-left:max(18px,var(--tg-content-left,0px));padding-right:max(18px,var(--tg-content-right,0px))}header{height:auto;min-height:65px;gap:8px}.header-brand .brand-icon{display:grid;width:34px;height:34px;border-radius:11px;font-size:28px}.header-title strong{font:22px/1.1 Georgia,serif;letter-spacing:-.03em}.header-title small{display:none}header>a{font-size:12px;padding:0 7px}
 main{margin:24px auto 28px;padding-bottom:20px}footer{font-size:12px;padding:18px 0 calc(var(--nav-height) + max(env(safe-area-inset-bottom),var(--tg-content-bottom,0px)) + 18px)}h1{font-size:32px}h2{font-size:25px}h3{font-size:22px}.intro{font-size:15px;line-height:1.7}.eyebrow{font-size:10px;letter-spacing:.12em}
 .home-heading{display:block}.home-heading h1{font-size:30px}.home-heading .edition{display:none}.home-heading .intro{font-size:14px;max-width:32ch}.hero{padding:23px;margin:20px 0 16px;border-radius:22px;grid-template-columns:1fr}.hero:before{left:24px;right:24px}.hero h2{font-size:28px;line-height:1.22;margin-bottom:12px;max-width:20ch}.hero p{font-size:14px;margin-bottom:0}.hero-cover{display:none}.hero .btn{width:100%;min-width:0}.hero-meta{margin-bottom:15px;font-size:11px}.hero .eyebrow{font-size:10px}.learning-steps{margin-bottom:22px}.learning-steps li{gap:6px;padding:10px 4px;font-size:11px}.learning-steps span{font-size:15px}
 .grid{gap:14px}.card,.task-card{padding:20px;border-radius:18px}.card p{font-size:15px}.card-top{margin-bottom:12px}.section-head{margin-top:27px}.section-head h2{font-size:24px}.section-head .text-link{font-size:13px}.row{gap:10px}.row .btn{font-size:13px;padding:10px 13px;min-height:44px}.row .number{min-width:34px;width:34px;height:38px;font-size:20px}.row-main{flex-basis:calc(100% - 48px)}.row .btn{margin-left:44px}.actions .btn{flex:1 1 170px}.lesson .actions .btn,.task-card .actions .btn{flex:1 1 100%}.lesson h1{font-size:30px;line-height:1.2}.lesson-copy{padding:20px;font-size:18px;line-height:1.85}.lesson-copy h2{font-size:26px}.inquiry{padding:17px}.inquiry p{font-size:17px}.inquiry small{font-size:13px}.option{font-size:16px}.feedback{padding:18px}.module-title{font-size:15px}.module .topics{padding:0 14px 14px}details.module>summary{padding:16px 14px}.topic ul{font-size:14px}.topic .text-link{font-size:13px}.timeline article{padding:16px}.timeline strong{font-size:21px}.timeline p{font-size:14px}.source-list{font-size:13px}
 #notice:not(:empty){bottom:calc(var(--nav-height) + max(env(safe-area-inset-bottom),var(--tg-content-bottom,0px)) + 12px);width:max-content;max-width:calc(100vw - 30px)}
 body.keyboard-open aside{visibility:hidden;pointer-events:none}body.keyboard-open #notice:not(:empty){bottom:16px}
}
@media(max-width:350px){.workspace{padding-left:max(14px,var(--tg-content-left,0px));padding-right:max(14px,var(--tg-content-right,0px))}nav{gap:2px}nav a{font-size:9px}.hero{padding:20px}.hero h2{font-size:26px}.learning-steps li{font-size:10px;gap:4px}}
@media(prefers-reduced-motion:no-preference){main{animation:none}.btn,.option,nav a{transition:background .12s,border-color .12s,box-shadow .12s}}
@media(prefers-contrast:more){.muted,.skill,.source-list,.topic ul,footer{color:#34492e}.card,.task-card,.option,.recall{border-color:#698252}aside{background:#fffef9}}
@media(prefers-reduced-transparency:reduce){aside{background:#fbfcf6;backdrop-filter:none}}