:root{--ink:#172b42;--muted:#586a7b;--blue:#174fe1;--line:#dce3eb;--paper:#f4f7fb;--nav:#102c42;--teal:#007d78}*{box-sizing:border-box}body{margin:0;font:16px/1.65 system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;color:var(--ink);background:var(--paper)}a{color:var(--blue)}button,select,textarea{font:inherit}button,a,summary{touch-action:manipulation}button{cursor:pointer}a:focus-visible,button:focus-visible,summary:focus-visible,select:focus-visible,textarea:focus-visible{outline:3px solid #e99424;outline-offset:4px}.skip{position:fixed;top:-100px;z-index:99;background:white;padding:12px}.skip:focus{top:0}aside{position:fixed;width:268px;inset:0 auto 0 0;background:var(--nav);color:white;padding:30px 22px;overflow:auto}.brand{display:flex;align-items:center;gap:12px;color:white;text-decoration:none;font-size:23px;font-weight:750;line-height:1.2;margin-bottom:38px}.brand-icon{font-size:17px;border:1px solid #6d9db3;border-radius:10px;padding:10px;color:#9de4e0}.brand-small{display:block;font-size:10px;letter-spacing:1.5px;margin-top:8px;color:#b6c8d6}nav a{display:flex;gap:9px;align-items:center;color:#c3d2df;text-decoration:none;padding:10px 12px;margin:3px 0;border-radius:7px;font-size:14px;line-height:1.45}nav a:hover,nav a.active{background:#23445e;color:white}nav a.active{box-shadow:inset 3px 0 #78d8cd}.navlabel{font-size:12px;letter-spacing:1.6px;color:#aabfce;margin:28px 12px 12px}.num{color:#8eaabe;font-size:12px;min-width:22px}.tag{font-size:12px;background:#2c626a;color:#c1f3e7;border-radius:4px;padding:1px 6px;margin-left:auto}.aside-foot{font-size:12px;color:#a9bfce;border-top:1px solid #365166;margin-top:24px;padding-top:18px}.shell{margin-left:268px}header{height:76px;background:white;border-bottom:1px solid var(--line);padding:0 46px;display:flex;align-items:center;justify-content:space-between;font-size:12px;letter-spacing:1.6px}header b{color:#9aabba;padding:0 12px}.print{background:white;border:1px solid var(--line);border-radius:6px;padding:7px 13px;color:var(--muted);font-size:14px;letter-spacing:0}main{max-width:1280px;margin:auto;padding:40px 46px 60px;min-height:80vh}.eyebrow{font-size:12px;font-weight:750;color:var(--teal);letter-spacing:1.8px;text-transform:uppercase}h1{font-size:clamp(30px,3.1vw,44px);letter-spacing:-1.3px;line-height:1.15;margin:13px 0 20px}h2{font-size:25px;letter-spacing:-.5px;line-height:1.3;margin:26px 0 15px}h3{font-size:19px;line-height:1.4;margin:10px 0}p{margin:12px 0}.intro{color:var(--muted);max-width:690px;font-size:17px}.hero{display:grid;grid-template-columns:1.2fr 1fr;gap:25px;padding-bottom:30px;align-items:center}.diagram{background:#eaf0f8;border:1px solid #d6e0ee;border-radius:12px;padding:18px}.diagram svg{width:100%;display:block;max-height:230px}.diagram p{font-size:12px;text-align:center;color:#51657d;margin:0}.stats{display:flex;gap:30px;border-block:1px solid var(--line);padding:18px 0;margin:5px 0 30px}.stats b{font-size:20px;margin-right:7px}.stats span{color:var(--muted);font-size:14px}.sectionhead{display:flex;justify-content:space-between;align-items:baseline;gap:20px}.sectionhead small{color:var(--muted)}.grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}.card{background:white;border:1px solid var(--line);border-radius:10px;padding:23px;text-decoration:none;color:var(--ink);display:block;transition:transform .15s,border-color .15s}.card:hover{border-color:#91afea;transform:translateY(-2px)}.card .index{font-size:13px;color:var(--teal);font-weight:750;letter-spacing:1px}.card p{font-size:14px;color:var(--muted)}.card .bottom{border-top:1px solid #edf0f5;padding-top:12px;margin-top:20px;font-size:13px;display:flex;justify-content:space-between}.feature{background:#103b53;color:white;border-radius:12px;padding:27px 30px;display:flex;justify-content:space-between;gap:20px;align-items:center;margin:30px 0}.feature p{color:#c1d6e3;max-width:640px}.button{display:inline-block;background:var(--blue);color:white;border:0;border-radius:6px;padding:10px 18px;text-decoration:none;font-weight:650;font-size:14px;white-space:nowrap}.feature .button{background:#b8f2e4;color:#153d46}.meta{display:flex;flex-wrap:wrap;gap:9px;margin:22px 0}.pill{background:#e7edf5;border-radius:4px;padding:4px 10px;font-size:13px;color:#425c73}.tabs{display:flex;gap:6px;border-bottom:1px solid var(--line);margin:28px 0 25px;flex-wrap:wrap}.tabs button{border:0;background:transparent;color:var(--muted);padding:12px 17px;font-weight:650;border-bottom:3px solid transparent}.tabs button[aria-selected=true]{color:var(--blue);border-color:var(--blue)}.lesson-grid{display:grid;grid-template-columns:minmax(0,1fr) 260px;gap:24px}.sheet{background:white;border:1px solid var(--line);padding:28px;border-radius:9px;min-width:0}.sheet h2:first-child{margin-top:0}.note{background:#eaf5f3;border-left:3px solid var(--teal);padding:17px 21px;border-radius:0 7px 7px 0;margin:22px 0}.note p{margin:0}.goal{font-size:14px}.goal ol,.goal ul{padding-left:22px}.goal li{margin:10px 0}.task{padding:24px;background:white;border:1px solid var(--line);border-radius:9px;margin:16px 0}.task:first-child{margin-top:0}.task-num{color:var(--teal);font-size:12px;letter-spacing:1px;font-weight:700}.task textarea{width:100%;min-height:100px;margin:15px 0 6px;border:1px solid #bdcbd8;border-radius:5px;padding:12px;resize:vertical;background:#fbfcfe;color:var(--ink)}details{border-top:1px solid var(--line);padding-top:12px;margin-top:14px}summary{cursor:pointer;color:var(--blue);font-weight:650;font-size:14px}details .answer{padding:12px 0;color:#334e62}.tiny{font-size:12px;color:var(--muted)}table{border-collapse:collapse;width:100%;font-size:14px;margin:16px 0}th,td{text-align:left;padding:11px 12px;border:1px solid var(--line);vertical-align:top}th{background:#eaf0f7}pre{white-space:pre-wrap;overflow-wrap:anywhere;font:14px/1.7 ui-monospace,monospace;padding:18px;background:#122d43;color:#e6f1fa;border-radius:7px}code{font-size:.9em}.scroll{overflow:auto}.quiz{margin:20px 0}.options{display:grid;grid-template-columns:repeat(3,1fr);gap:10px}.option{padding:15px;background:white;border:1px solid #b4c5d6;border-radius:7px;color:var(--ink)}.option:hover{background:#eaf0ff}.option.correct{border-color:var(--teal);background:#dff5ed}.option.wrong{border-color:#b84c3c;background:#fff0eb}.feedback{min-height:26px;margin:12px 0;font-size:15px}.bottomnav{display:flex;justify-content:space-between;gap:15px;margin-top:30px}.bottomnav a{font-size:14px;text-decoration:none}.plan-row a{font-weight:650;text-decoration:none}.checklist label{display:block;padding:7px 0}.checklist input{width:17px;height:17px;margin-right:10px;accent-color:var(--teal)}footer{padding:24px 46px;border-top:1px solid var(--line);font-size:12px;color:var(--muted);display:flex;justify-content:space-between;gap:15px}.source{font-size:13px;border-top:1px solid var(--line);padding-top:20px;margin-top:25px;color:var(--muted)}@media(max-width:1150px){.grid{grid-template-columns:repeat(2,1fr)}.hero{grid-template-columns:1fr}.hero .diagram{max-width:530px}.lesson-grid{grid-template-columns:1fr}.goal{display:grid;grid-template-columns:1fr 1fr;gap:25px}}@media(max-width:760px){aside{position:relative;width:100%;padding:18px}.brand{margin-bottom:18px}.brand-small{font-size:10px}nav{display:flex;flex-wrap:wrap;gap:3px}nav a{font-size:14px;padding:7px 10px}#chapters,.navlabel,.aside-foot{display:none}.shell{margin:0}header{height:58px;padding:0 20px}main{padding:25px 20px}.grid{grid-template-columns:1fr}.hero{padding-bottom:15px}.stats{gap:15px;flex-wrap:wrap}.feature{display:block}.feature .button{margin-top:10px}.sheet{padding:20px}.goal{display:block}.options{grid-template-columns:1fr}.sectionhead{display:block}footer{padding:20px;display:block}.tabs button{padding:10px}.bottomnav{flex-wrap:wrap}}@media print{aside,header,footer,.tabs,.bottomnav,.button,.quiz button{display:none!important}.shell{margin:0}main{padding:0;max-width:none}body{background:white;font-size:11pt}.lesson-grid,.grid{display:block}.sheet,.task,.card{break-inside:avoid;margin-bottom:15px}.task textarea{min-height:80px}.hero{display:block}.diagram{max-width:550px}details:not([open]){display:none}h1{font-size:26pt}}

.page-tabs a{color:var(--blue);font-size:15px;padding:12px 17px;text-decoration:none;background:white;border:1px solid var(--line)}.page-tabs a:hover{background:#eaf0ff}.page-tabs{margin-bottom:25px}section[id]{scroll-margin-top:20px}html{scroll-behavior:smooth}@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}}@media print{.page-tabs{display:none!important}}
