:root{color-scheme:dark;--ink: #e6f7ff;--muted: #b9d3e3;--accent: #5ef0ff;--line: #32475c;--panel: #101c2c;background:#01030a;color:var(--ink);font-family:Inter,system-ui,sans-serif;line-height:1.55}*,*:before,*:after{box-sizing:border-box}body{margin:0}a{color:var(--accent);text-underline-offset:.25em}button,select,input{font:inherit;color:inherit}button{cursor:pointer}:focus-visible{outline:2px solid var(--accent);outline-offset:3px}[hidden]{display:none!important}.story{--gutter: clamp(1rem, 5vw, 5rem);--left: max(var(--gutter), env(safe-area-inset-left));--right: max(var(--gutter), env(safe-area-inset-right))}.screen{min-block-size:100vh;min-block-size:100svh;display:grid;padding-inline:var(--left) var(--right);padding-block:max(1rem,env(safe-area-inset-top)) max(1.25rem,env(safe-area-inset-bottom))}.panel{width:min(100%,42rem);min-inline-size:0}.panel h1,.panel h2{margin:0 0 .65rem;font-weight:700;line-height:1.06;letter-spacing:-.035em;text-wrap:balance;overflow-wrap:anywhere}.panel p{margin:0;color:var(--muted)}.slide-actions{display:flex;align-items:center;flex-wrap:wrap;gap:.35rem 1rem;margin-block-start:.65rem}.slide-actions a{display:inline-flex;align-items:center;min-block-size:2.75rem}.screen-hero{grid-template-rows:auto 1fr;background:radial-gradient(ellipse at 26% 46%,#10283d,transparent 75%)}.masthead a{display:inline-flex;align-items:center;min-block-size:2.75rem;color:var(--ink);text-decoration:none;font-size:.85rem;font-weight:700;letter-spacing:.16em;text-transform:uppercase}.intro{align-self:center;padding-block:1rem clamp(2rem,8vh,6rem)}.intro h1{font-size:clamp(2.65rem,8vw,5.4rem)}.intro h1 em{color:var(--accent);font-style:normal}.intro p{font-size:clamp(1.05rem,2vw,1.3rem);max-width:42ch}.intro .slide-actions{margin-block-start:1.25rem}.start-lessons,.lesson-play{border:1px solid #54738a;background:transparent;padding-inline:.85rem}.start-lessons{gap:.5rem;text-decoration:none;font-weight:650}.start-lessons:hover,.lesson-play:hover{border-color:var(--accent)}.lesson{align-content:center;background:#0f212d}.lesson .panel{justify-self:center}.lesson--film{--frame-before: calc(100% * 28 / 42);--frame-after: calc(100% * 30 / 42);align-content:stretch;padding:0}.lesson--film .panel{display:grid;grid-template-columns:minmax(0,1fr);grid-template-rows:auto minmax(clamp(9rem,45svh,30rem),1fr) auto;isolation:isolate;width:100%}.lesson--film .lesson-title{grid-area:1 / 1;margin:0;padding:max(1rem,env(safe-area-inset-top)) var(--right) .5rem var(--left)}.lesson--film .lesson-copy{grid-area:3 / 1;padding:.5rem var(--right) max(1.25rem,env(safe-area-inset-bottom)) var(--left)}.lesson-title{font-size:clamp(1.85rem,6vw,4rem)}.lesson-summary{max-inline-size:60ch;font-size:clamp(1rem,1.5vw,1.2rem)}.lesson-media{grid-row:1 / -1;grid-column:1;display:grid;grid-template-columns:minmax(0,1fr);grid-template-rows:subgrid;position:relative;z-index:-1;overflow:clip;pointer-events:none}.lesson-media>*{position:absolute;grid-area:2 / 1 / 3 / 2;inset-inline:0;inset-block-start:calc(-1 * var(--frame-before));width:100%;height:calc(100% + var(--frame-before) + var(--frame-after))}.lesson-poster img{display:block;width:100%;height:100%}.lesson-media video,.lesson-poster img{object-fit:contain}.lesson-media video{opacity:0}.lesson-media video[data-ready]{opacity:1}.lesson-play{min-inline-size:4.25rem;min-block-size:2.75rem;border-radius:.25rem}.lesson .slide-actions{font-size:.875rem}.lesson .lesson-status{margin-block-start:.25rem;font-size:.875rem}.lesson .lesson-status:empty{margin:0}@media(orientation:landscape){.lesson--film{--frame-before: 10%;--frame-after: 15%}.lesson-title{font-size:clamp(1.85rem,4.5vw,4rem)}}.curriculum{width:min(75rem,100% - var(--left) - var(--right));margin-inline:auto;padding-block:1rem max(2rem,env(safe-area-inset-bottom))}.hint{font-size:.875rem;color:var(--muted)}.guide-panel{border-block:1px solid var(--line)}.guide-panel>summary{min-height:2.75rem;padding-block:.65rem;cursor:pointer}[data-watch-lesson]{display:inline-block;margin-block-start:.5rem}.toolbar{display:grid;grid-template-columns:minmax(0,1.4fr) minmax(0,1fr) auto;align-items:start;gap:1rem;padding-block:1rem;border-top:1px solid var(--line)}.field{min-width:0}.field label{display:block;margin-bottom:.3rem;font-size:.875rem;font-weight:650}.field .hint{margin:.4rem 0 0}.field select,.field input,[data-toggle-map]{min-height:2.75rem;background:var(--panel);border:1px solid var(--line);border-radius:.35rem;padding:.45rem .65rem}.field select,.field input{width:100%}.field input::placeholder{color:var(--muted);opacity:1}[data-toggle-map]{margin-top:1.65rem}[data-toggle-map][aria-pressed=true]{border-color:var(--accent);color:var(--accent)}[data-toggle-map]:disabled{cursor:default;opacity:.65}.map{margin:0 0 1.25rem}.map-stage{background:#0b0b0b;border:1px solid var(--line);border-radius:.4rem;height:clamp(16rem,45vw,35rem)}.map-stage canvas{display:block;width:100%;height:100%;border-radius:inherit}.map figcaption{margin-top:.5rem;color:var(--muted);font-size:.875rem}.map-status:empty{display:none}.study-guide{display:grid;grid-template-columns:minmax(15rem,1fr) minmax(0,1.8fr);gap:clamp(1rem,4vw,4rem)}.concept-index,.concept-detail{min-width:0;border-top:1px solid var(--line);padding-top:1rem}.concept-index h2{font-size:1.35rem;margin:0}.concept-index p{margin:.25rem 0 .75rem}.concept-index h3{margin:1.1rem 0 .45rem;font-size:1rem}.concept-index h4{margin:.8rem 0 .3rem;font-size:.875rem;color:var(--muted)}.concept-index ul,.concept-detail ul{list-style:none;padding:0;margin:0}.concept-index button{width:100%;min-height:2.75rem;text-align:start;border:0;border-inline-start:2px solid var(--line);background:transparent;padding:.4rem .65rem}.concept-index button:hover,.concept-index button[aria-current=true]{background:var(--panel)}.concept-index button[aria-current=true]{color:var(--accent);border-color:var(--accent)}.concept-detail h2{font:400 clamp(1.8rem,4vw,3.1rem)/1.08 Georgia,serif;margin:.45rem 0 .8rem;overflow-wrap:anywhere}.concept-detail h3{font-size:1rem;margin:0 0 .35rem}.concept-detail p{margin:0}.concept-detail section{margin-top:1.3rem}.concept-detail li+li{margin-top:.65rem}.concept-path,.provenance{color:var(--muted);font-size:.875rem}.concept-path{color:var(--accent)}.explanation{font-size:1.1rem;max-width:42rem}.learning-check{background:var(--panel);border-inline-start:2px solid var(--accent);padding:.85rem 1rem}.concept-link{background:transparent;border:0;padding:.1rem 0;text-align:start;color:var(--accent);text-decoration:underline;text-underline-offset:.2em}.concept-link:hover{color:var(--ink)}@media(max-width:45rem){.toolbar{grid-template-columns:minmax(0,1fr) auto;gap:.75rem}.toolbar .field:first-child{grid-column:1 / -1}.study-guide{grid-template-columns:minmax(0,1fr)}.concept-index{padding-inline:.25rem}}
