:root{--ink:#132e42;--muted:#526575;--blue:#1458c2;--blue-dark:#103d88;--pale:#eaf2ff;--teal:#077969;--orange:#f68d48;--paper:#f8fafb;--line:#dbe4ec;--white:#fff;--radius:18px;--shadow:0 16px 45px #1634500b}*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:100px}body{margin:0;background:var(--paper);color:var(--ink);font-family:Inter,-apple-system,BlinkMacSystemFont,'Segoe UI',sans-serif;font-size:16px;line-height:1.7}a{color:var(--blue);text-decoration:none}a:hover{text-decoration:underline}button,input,select{font:inherit}button,a,input,select,summary{touch-action:manipulation}button{cursor:pointer}button:disabled{cursor:default;opacity:.6}a:focus-visible,button:focus-visible,input:focus-visible,select:focus-visible,summary:focus-visible{outline:3px solid #df793a;outline-offset:4px}h1,h2,h3{line-height:1.18;letter-spacing:-.035em;margin:0 0 18px;font-weight:750}h1{font-size:clamp(2.3rem,4.7vw,4.7rem)}h2{font-size:clamp(1.7rem,2.5vw,2.5rem)}h3{font-size:1.23rem;letter-spacing:-.02em}p{margin:0 0 18px}ul,ol{padding-left:24px}li{margin-bottom:8px}svg{max-width:100%}.wrap{width:min(1180px,calc(100% - 48px));margin:auto}.skip{position:absolute;top:-100px;left:16px;background:white;padding:12px;z-index:20}.skip:focus{top:8px}.topline{background:#132f44;color:#dae7f0;font-size:12px;letter-spacing:.04em;padding:7px 0}.topline .wrap{display:flex;justify-content:space-between;gap:16px}.topline a{color:#fff}.header{position:sticky;top:0;background:#fffffff5;border-bottom:1px solid var(--line);z-index:10;backdrop-filter:blur(12px)}.header-inner{display:flex;align-items:center;gap:26px;min-height:82px}.brand{display:flex;align-items:center;gap:11px;color:var(--ink);font-weight:850;font-size:25px;letter-spacing:-1px;flex-shrink:0}.brand:hover{text-decoration:none}.brand small{color:var(--blue);font:inherit}.brand-icon{width:37px;height:37px;display:grid;place-items:center;border-radius:12px;color:white;background:var(--blue);font-size:26px}.nav{display:flex;align-items:center;gap:24px;flex:1;justify-content:center}.nav a{font-size:14px;font-weight:600;color:#425766}.nav a[aria-current=page]{color:var(--blue)}.search-open,.menu-toggle{background:transparent;border:1px solid var(--line);border-radius:10px;padding:9px 13px;color:var(--ink)}.menu-toggle{display:none}.button{display:inline-flex;align-items:center;justify-content:center;gap:10px;background:var(--blue);border:1px solid var(--blue);border-radius:10px;color:white;padding:12px 20px;font-size:14px;font-weight:700;text-decoration:none!important;transition:background .15s,transform .15s}.button:hover{background:var(--blue-dark);transform:translateY(-1px)}.button.secondary{background:white;color:var(--ink);border-color:var(--line)}.button.secondary:hover{background:var(--pale)}.button.small{padding:9px 14px;font-size:13px}.hero{padding:65px 0 52px;position:relative;overflow:hidden;background:linear-gradient(110deg,#f8fafb 0%,#f8fafb 40%,#eaf3fc 100%)}.hero-grid{display:grid;grid-template-columns:1.12fr 1fr;gap:50px;align-items:center}.eyebrow{color:var(--teal);text-transform:uppercase;letter-spacing:.13em;font-size:11px;font-weight:800;display:flex;gap:9px;align-items:center;margin-bottom:20px}.eyebrow:before{content:'';background:var(--teal);height:6px;width:6px;border-radius:50%}.hero h1 span{color:var(--blue)}.hero .lead{font-size:18px;max-width:560px;color:var(--muted);line-height:1.65}.actions{display:flex;flex-wrap:wrap;gap:12px;margin:27px 0 21px}.micro{font-size:12px;color:var(--muted)}.hero-art{position:relative;min-height:350px}.physics-board{width:100%;height:auto;display:block}.float-note{position:absolute;left:15px;bottom:14px;background:white;border:1px solid var(--line);border-radius:12px;box-shadow:var(--shadow);padding:13px 17px;font-size:13px;line-height:1.5}.float-note b{display:block;color:var(--teal)}.stats{background:white;border:1px solid var(--line);border-radius:var(--radius);display:grid;grid-template-columns:repeat(4,1fr);margin-top:30px;box-shadow:var(--shadow)}.stat{padding:21px 28px;border-right:1px solid var(--line)}.stat:last-child{border:0}.stat strong{display:block;font-size:22px;letter-spacing:-.04em}.stat span{font-size:12px;color:var(--muted)}.section{padding:58px 0}.section.soft{background:#edf3f7}.section-head{display:flex;justify-content:space-between;align-items:end;gap:20px;margin-bottom:26px}.section-head h2{margin-bottom:8px}.section-head p{margin:0;color:var(--muted)}.grid{display:grid;gap:20px}.grid.three{grid-template-columns:repeat(3,1fr)}.grid.two{grid-template-columns:repeat(2,1fr)}.card{background:white;border:1px solid var(--line);border-radius:var(--radius);padding:28px;box-shadow:var(--shadow)}.card p{color:var(--muted);font-size:14px}.card .icon{display:grid;place-items:center;width:43px;height:43px;background:var(--pale);color:var(--blue);border-radius:12px;margin-bottom:20px;font-size:20px;font-weight:700}.card .card-link{font-size:14px;font-weight:700}.card-link:after{content:' →'}.card h3 a{color:var(--ink)}.notice{padding:20px 24px;border-left:4px solid var(--orange);border-radius:0 12px 12px 0;background:#fff5e9;margin:22px 0;color:#69431e;font-size:14px}.notice p:last-child{margin-bottom:0}.notice.info{background:var(--pale);border-color:var(--blue);color:#28476e}.notice.success{background:#e7f6f0;border-color:var(--teal);color:#22564b}.notice a{text-decoration:underline}.badge{display:inline-block;background:#e9f5ef;color:#20664f;border-radius:20px;padding:3px 10px;font-size:11px;font-weight:700;letter-spacing:.025em}.badge.amber{background:#fff0dc;color:#89521c}.badge.blue{background:var(--pale);color:var(--blue)}.pathway{display:grid;grid-template-columns:repeat(5,1fr);border-top:1px solid var(--line);gap:24px;margin-top:34px}.path-step{padding-top:22px;position:relative}.path-step:before{content:'';position:absolute;top:-5px;width:9px;height:9px;background:var(--blue);border-radius:50%}.path-step small{font-size:11px;color:var(--blue);font-weight:800}.path-step h3{margin:7px 0;font-size:17px}.path-step p{font-size:13px;color:var(--muted)}.home-bottom{background:#153c57;color:white;border-radius:22px;padding:38px 42px;display:flex;justify-content:space-between;gap:26px;align-items:center}.home-bottom h2{font-size:29px}.home-bottom p{color:#d1dfe9;margin:0}.home-bottom .button{background:white;color:var(--ink);border:0;flex-shrink:0}.crumbs{padding:22px 0 0;font-size:12px;color:var(--muted)}.crumbs a{color:var(--muted)}.page-hero{padding:35px 0 28px;max-width:850px}.page-hero h1{font-size:clamp(2.4rem,4vw,3.6rem)}.page-hero .lead{font-size:18px;color:var(--muted);max-width:760px}.meta{display:flex;gap:15px;flex-wrap:wrap;color:var(--muted);font-size:12px}.content-layout{display:grid;grid-template-columns:minmax(0,1fr) 265px;gap:36px;padding-bottom:65px}.article{min-width:0}.article>section,.article>.card{margin-bottom:25px}.article h2{font-size:26px;margin-top:8px}.article h3{margin-top:24px}.article .card h3:first-child{margin-top:0}.aside{align-self:start;position:sticky;top:105px;border:1px solid var(--line);border-radius:14px;background:white;padding:22px;font-size:13px}.aside strong{font-size:14px}.aside a{display:block;padding:8px 0;border-bottom:1px solid #edf1f4}.aside p{font-size:12px;color:var(--muted);margin:20px 0 0}.table-wrap{overflow:auto;width:100%;border:1px solid var(--line);border-radius:12px;background:white;margin:20px 0}table{border-collapse:collapse;width:100%;font-size:14px;min-width:440px}th,td{text-align:left;padding:15px 18px;border-bottom:1px solid var(--line);vertical-align:top}th{background:#edf3fa;font-size:12px;color:#34536d}tr:last-child td{border:0}td:first-child{font-weight:600}.sources{padding:22px;border:1px solid var(--line);border-radius:12px;background:#f0f4f7;font-size:12px;color:var(--muted);margin:32px 0 0}.sources strong{display:block;color:var(--ink);margin-bottom:8px}.sources a{display:inline-block;margin:3px 15px 3px 0;text-decoration:underline}.field{display:flex;flex-direction:column;gap:7px;margin-bottom:18px}.field label,legend{font-size:14px;font-weight:650}.field input,.field select,.filter{border:1px solid #becdd9;background:white;color:var(--ink);border-radius:9px;padding:11px 12px;width:100%;min-height:46px}.field small{font-size:12px;color:var(--muted)}.field-row{display:grid;grid-template-columns:1fr 1fr;gap:20px}fieldset{border:0;padding:0;margin:0}.check-row{display:flex;align-items:start;gap:10px;padding:10px 0;font-size:14px;cursor:pointer}.check-row input{margin-top:7px;accent-color:var(--blue);width:18px;height:18px;flex-shrink:0}.tool-result{margin-top:20px;padding:20px;border-radius:12px;background:var(--pale)}.tool-result:empty{display:none}.tool-result h3{margin-top:0}.tool-result p:last-child{margin-bottom:0}.toolbar{display:flex;gap:12px;flex-wrap:wrap;margin:20px 0}.toolbar .field{margin:0;flex:1;min-width:140px}.toolbar label{font-size:12px}.syllabus-progress{background:var(--pale);border-radius:12px;padding:20px;margin-bottom:24px}.progress-track{height:8px;background:#d5e2f3;border-radius:5px;overflow:hidden;margin:12px 0}.progress-fill{height:100%;width:0;background:var(--blue);transition:width .2s}.syllabus-group{border:1px solid var(--line);border-radius:12px;margin-bottom:15px;background:white;overflow:hidden}.syllabus-group summary{list-style:none;padding:18px 22px;cursor:pointer;font-size:17px;font-weight:700;display:flex;justify-content:space-between;gap:15px}.syllabus-group summary:after{content:'+';color:var(--blue)}.syllabus-group[open] summary:after{content:'−'}.syllabus-group>div{padding:0 22px 18px}.syllabus-group .check-row{border-top:1px solid #edf0f4}.syllabus-group .check-row span b{display:block;font-size:14px}.syllabus-group .check-row span small{color:var(--muted);font-size:12px;display:block;line-height:1.55}.faq{border-bottom:1px solid var(--line);padding:18px 0}.faq summary{cursor:pointer;font-weight:650;font-size:16px}.faq>div{margin-top:14px;color:var(--muted);font-size:14px}.paper-card{padding:22px;border:1px solid var(--line);border-radius:13px;background:white;margin-bottom:16px;display:flex;align-items:center;justify-content:space-between;gap:20px}.paper-card h3{margin:9px 0 7px;font-size:18px}.paper-card p{font-size:12px;color:var(--muted);margin:0}.paper-card .actions{margin:0;flex-shrink:0;max-width:210px;flex-wrap:wrap}.paper-card .actions .button{width:100%}.question{background:white;border:1px solid var(--line);border-radius:16px;padding:28px;margin:20px 0}.question legend{font-size:18px;line-height:1.6;margin:14px 0 20px;font-weight:600}.option{padding:12px 15px;margin:10px 0;border:1px solid var(--line);border-radius:10px;display:flex;align-items:start;gap:11px;cursor:pointer;font-size:14px}.option input{margin-top:6px;accent-color:var(--blue)}.option:has(input:checked){border-color:var(--blue);background:var(--pale)}.answer{margin-top:18px;padding:18px;background:#eaf7f1;border-radius:10px;font-size:14px;white-space:pre-line}.answer.incorrect{background:#fff2e7}.tabs{display:flex;gap:10px;flex-wrap:wrap;margin:20px 0}.tabs button{padding:10px 17px;border:1px solid var(--line);border-radius:9px;background:white;color:var(--ink)}.tabs button[aria-pressed=true]{background:var(--blue);color:white;border-color:var(--blue)}.plan-week{display:grid;grid-template-columns:100px 1fr;gap:20px;border-bottom:1px solid var(--line);padding:20px 0}.plan-week strong{font-size:13px;color:var(--blue)}.plan-week h3{margin:0 0 7px}.plan-week p{margin:0;color:var(--muted);font-size:14px}.footer{background:#fff;border-top:1px solid var(--line);padding:40px 0 20px}.footer-grid{display:grid;grid-template-columns:2fr 1fr 1fr;gap:50px}.footer p{font-size:12px;color:var(--muted);max-width:430px;margin-top:15px}.footer h3{font-size:13px;letter-spacing:0}.footer a:not(.brand){display:block;font-size:12px;margin:7px 0;color:var(--muted)}.footer-bottom{border-top:1px solid var(--line);margin-top:25px;padding-top:18px;display:flex;justify-content:space-between;gap:15px;font-size:11px;color:var(--muted)}.search-dialog{width:min(650px,calc(100% - 30px));padding:0;border:1px solid var(--line);border-radius:18px;box-shadow:0 30px 100px #0003;max-height:80vh;color:var(--ink)}.search-dialog::backdrop{background:#0d263c90;backdrop-filter:blur(3px)}.search-header{display:flex;gap:10px;padding:20px;border-bottom:1px solid var(--line)}.search-header input{border:0;padding:8px;min-width:0;flex:1;background:white;color:var(--ink)}.search-header button{background:var(--pale);border:0;border-radius:8px;padding:8px 12px}.search-results{padding:10px 20px 22px}.search-results a{display:block;padding:14px;border-bottom:1px solid var(--line)}.search-results a strong{display:block;color:var(--ink)}.search-results a small{color:var(--muted)}.empty{padding:30px;text-align:center;color:var(--muted)}[hidden]{display:none!important}.print-btn{background:none;border:0;color:var(--blue);padding:0;font-size:12px;cursor:pointer}.js-required{display:none}.no-js .js-required{display:block;background:#fff0dc;padding:15px}.no-js .tool-interactive{display:none}.formula{font-family:Georgia,serif;font-size:20px;background:#f0f5fb;padding:18px;border-radius:9px;text-align:center;margin:15px 0}.toc-links{display:flex;gap:12px;flex-wrap:wrap;margin-bottom:22px}.toc-links a{padding:6px 12px;border:1px solid var(--line);border-radius:20px;font-size:12px;background:white}.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(max-width:1050px){.nav{gap:14px}.header-inner{gap:16px}.hero-grid{gap:25px}.hero h1{font-size:56px}.content-layout{grid-template-columns:minmax(0,1fr) 220px;gap:25px}}
@media(max-width:800px){.nav{display:none;position:absolute;top:82px;left:0;right:0;background:white;border-bottom:1px solid var(--line);padding:20px 24px;flex-direction:column;align-items:stretch}.nav.open{display:flex}.header-inner{min-height:72px}.nav{top:72px}.header-inner .brand{margin-right:auto}.menu-toggle{display:block}.search-open{font-size:0;padding:10px}.search-open:before{content:'⌕';font-size:24px;line-height:1}.hero{padding:40px 0}.hero-grid{grid-template-columns:1fr}.hero h1{font-size:clamp(42px,9vw,64px);max-width:600px}.hero-art{min-height:0;max-width:480px;margin:auto}.physics-board{max-height:320px}.stats{grid-template-columns:repeat(2,1fr);margin-top:30px}.stat{padding:18px 22px}.stat:nth-child(2){border-right:0}.stat:nth-child(-n+2){border-bottom:1px solid var(--line)}.grid.three{grid-template-columns:1fr 1fr}.content-layout{grid-template-columns:1fr}.aside{position:static;display:none}.pathway{grid-template-columns:1fr 1fr 1fr;gap:22px}.home-bottom{align-items:start;flex-direction:column}.section{padding:42px 0}.topline .wrap span:last-child{display:none}.footer-grid{gap:25px;grid-template-columns:2fr 1fr 1fr}.paper-card{align-items:start}.paper-card .actions{max-width:165px}.paper-card .button{font-size:12px}}
@media(max-width:520px){.wrap{width:calc(100% - 32px)}.brand{font-size:23px}.hero .lead{font-size:16px}.hero-art{max-width:370px}.grid.three,.grid.two{grid-template-columns:1fr}.section-head{align-items:start;flex-direction:column}.section-head>a{font-size:13px}.card{padding:23px}.pathway{grid-template-columns:1fr;border:0;gap:5px}.path-step{border-left:1px solid var(--line);padding:0 0 20px 23px}.path-step:before{top:6px;left:-5px}.path-step p{margin:0}.footer-grid{grid-template-columns:1fr 1fr}.footer-grid>div:first-child{grid-column:1/-1}.footer-bottom{flex-direction:column}.field-row{grid-template-columns:1fr;gap:0}.paper-card{flex-direction:column}.paper-card .actions{max-width:none;width:100%;flex-wrap:nowrap}.paper-card .actions .button{width:auto;flex:1}.plan-week{grid-template-columns:1fr;gap:7px}.page-hero .lead{font-size:16px}.question{padding:20px}.home-bottom{padding:28px}.stats .stat strong{font-size:21px}.float-note{font-size:11px;bottom:4px}.topline{font-size:10px}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*{transition:none!important}}
@media print{.header,.topline,.footer,.aside,.search-dialog,.toolbar,.print-btn,.menu-toggle,.button{display:none!important}.wrap{width:100%}.content-layout{display:block}.card,.question,.syllabus-group{box-shadow:none;break-inside:avoid}body{font-size:11pt;background:white}.page-hero{padding:15px 0}a{color:inherit;text-decoration:underline}.section{padding:20px 0}}

.text-button{border:0;background:none;color:var(--muted);padding:0;text-align:left;font-size:12px;text-decoration:underline;cursor:pointer}.analytics-choice{position:fixed;z-index:90;bottom:18px;left:50%;transform:translateX(-50%);width:min(860px,calc(100% - 32px));padding:20px 24px;background:white;border:1px solid var(--line);border-radius:16px;box-shadow:0 8px 40px #102b3c30;display:flex;align-items:center;gap:24px}.analytics-choice strong{font-size:15px}.analytics-choice p{font-size:12px;line-height:1.5;margin:7px 0 0;color:var(--muted)}.analytics-choice .actions{margin:0;flex-shrink:0}.aside{max-height:calc(100vh - 125px);overflow:auto}@media(max-width:650px){.analytics-choice{padding:18px;display:block}.analytics-choice .actions{margin-top:14px}}@media print{.analytics-choice{display:none!important}}