/* The illustrated principles explorer. Scoped to avoid changing other pages. */
html:has(.principles-page){scroll-padding-top:0}
.principles-page{--essay-muted:#a7b0b8;--essay-line:#2a333b;--essay-blue:#66cdff;--essay-purple:#bca4ff}
.principles-page p{margin:0}
.principles-page h1,.principles-page h2,.principles-page h3,.principles-page h4{margin:0}
.principles-page figure{margin:0}
.principles-page [id]{scroll-margin-top:90px}
.principles-wrap{width:min(1380px,89%);margin-inline:auto}
.principles-kicker{display:flex;align-items:center;gap:10px;font:11px/1.6 var(--mono);letter-spacing:1.6px;color:var(--essay-blue)}
.principles-meta{font:10px/1.6 var(--mono);letter-spacing:1.1px;color:var(--essay-muted)}
.principles-page h2{font:700 clamp(40px,4.6vw,68px)/.98 var(--display);letter-spacing:-.6px;text-transform:uppercase}
.principles-page h2 span{color:var(--essay-muted)}
.principles-page a{transition:color .18s,border-color .18s,background-color .18s}
.principles-page a:hover{color:var(--essay-blue)}
.principles-page a:focus-visible,.principles-page summary:focus-visible{outline:2px solid var(--essay-blue);outline-offset:5px}
.principles-button{display:inline-flex;align-items:center;justify-content:space-between;gap:28px;min-height:48px;padding:12px 19px;background:#119ee3;border:1px solid #39b8f3;color:#03131e!important;font-size:13px;font-weight:700}
.principles-button:hover{background:#77d2ff}
.principles-button>span{font-size:20px;line-height:1}
.principles-thesis{padding-block:102px 100px}
.principles-thesis>.principles-kicker{margin-bottom:26px}
.principles-thesis-grid{display:grid;grid-template-columns:.9fr 1.1fr;gap:10%}
.principles-thesis h2{font-size:clamp(56px,6vw,87px)}
.principles-thesis h2 span{color:var(--essay-blue)}
.principles-prose{color:var(--essay-muted);font-size:16px;line-height:1.8}
.principles-prose p+p{margin-top:20px}
.principles-prose .principles-lead,.principles-lead{font-size:21px;line-height:1.5;color:#e8edf1;letter-spacing:-.25px}
.principles-prose strong{color:#e6edf2;font-weight:500}
.principles-text-link{display:inline-flex;gap:20px;color:var(--essay-blue);font:11px/1.7 var(--mono);border-bottom:1px solid #355464;padding-block:3px}
.principles-prose>.principles-text-link{margin-top:27px}
.principles-scale-guide{border-top:1px solid var(--essay-line);padding-block:52px 95px}
.principles-section-top{display:flex;justify-content:space-between;gap:20px;align-items:center;margin-bottom:30px}
.principles-guide-intro{display:grid;grid-template-columns:1.1fr 1fr;gap:9%;align-items:end}
.principles-guide-intro h2{font-size:clamp(38px,4vw,58px)}
.principles-guide-intro>p{font-size:14px;line-height:1.8;color:var(--essay-muted)}
.principles-cite{font:11px var(--mono);color:var(--essay-blue);white-space:nowrap}
.principles-scale-cards{display:grid;grid-template-columns:repeat(3,1fr);border:1px solid var(--essay-line);margin-top:37px;background:linear-gradient(115deg,#101a23,#111319)}
.principles-scale-cards>a{display:flex;gap:23px;padding:30px 24px;position:relative}
.principles-scale-cards>a+a{border-left:1px solid var(--essay-line)}
.principles-scale-cards>a:hover{background:#13222d;color:inherit}
.principles-type{font:600 80px/.95 var(--display);color:#314c61}
.principles-scale-cards h3{font:600 26px/1.2 var(--display);margin:8px 0}
.principles-scale-cards p{font-size:12px;max-width:180px;line-height:1.7;color:var(--essay-muted)}
.principles-scale-cards strong{display:block;font:500 28px/1.4 var(--mono);color:var(--essay-blue);margin-top:15px}
.principles-scale-cards strong>sup{font-size:15px}
.principles-scale-cards strong>small{font-size:13px}
.scale-card-arrow{position:absolute;right:15px;top:16px;color:var(--essay-blue);font-size:15px}
.principles-scale-footnotes{display:grid;grid-template-columns:1fr 1fr;gap:45px;margin-block:25px 28px;color:var(--essay-muted);font-size:13px;line-height:1.8}
.principles-scale-footnotes strong{display:block;color:#e1e7eb;font-weight:500;margin-bottom:5px}
.principles-scale-detail,.principles-contents{border-top:1px solid var(--essay-line);border-bottom:1px solid var(--essay-line)}
.principles-page summary{cursor:pointer;list-style:none;display:flex;align-items:center;justify-content:space-between;gap:20px;padding:18px 0;font-size:14px;color:#dbe5ec}
.principles-page summary::-webkit-details-marker{display:none}
.principles-page summary>span{color:var(--essay-blue)}
.principles-page details[open]>summary{color:var(--essay-blue)}
.principles-scale-detail>div{max-width:900px;padding:4px 0 25px;color:var(--essay-muted);font-size:14px;line-height:1.8}
.principles-scale-detail p+p{margin-top:16px}
.principles-scale-detail code{display:inline-block;font:12px var(--mono);padding:3px 5px;background:#16232e;color:#d1e8f7}
.principles-contents{border-top:0}
.principles-contents-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:35px;padding:17px 0 28px}
.principles-contents h3{font:11px var(--mono);letter-spacing:1px;color:var(--essay-blue);margin-bottom:16px}
.principles-contents ol{margin:0;padding:0;list-style:none}
.principles-contents li>a{font-size:13px;display:flex;justify-content:space-between;gap:12px;padding:9px 0;border-bottom:1px solid #202a32}
.principles-contents li>a>span{color:#66859a}
.principles-reading-key{display:grid;grid-template-columns:185px 1fr;gap:25px;margin-top:25px}
.principles-reading-key p{font-size:12px;color:var(--essay-muted);line-height:1.8}
.principles-stage-meta{display:flex;justify-content:space-between;align-items:center;flex-wrap:wrap;gap:10px;margin-bottom:21px;font:9px/1.6 var(--mono);color:#aab9c6}
.principles-stage-meta>span:first-child{flex:1;min-width:130px}
.principles-status{padding:3px 7px;border:1px solid #3d494f;font-size:8px;text-transform:uppercase;letter-spacing:.6px;white-space:nowrap}
.status-established{color:#a6dccb;border-color:#34584e;background:#14251f}
.status-development{color:#93d6fd;border-color:#2a5069;background:#142430}
.status-future{color:#cbb7ff;border-color:#574872;background:#211d2e}
.principles-stage-subtitle{font:10px/1.6 var(--mono);letter-spacing:.4px;color:var(--essay-blue);margin-bottom:7px!important}
.principles-unlocks{margin-block:25px 23px;border-top:1px solid #293b48;padding-top:18px}
.principles-unlocks h4{font:10px var(--mono);color:var(--essay-blue);letter-spacing:1.2px}
.principles-unlocks ul{padding:0;margin:12px 0 0;list-style:none}
.principles-unlocks li{font-size:13px;line-height:1.7;margin-block:5px;padding-left:19px;position:relative;color:#e1e8ed}
.principles-unlocks li:before{content:"+";font:13px var(--mono);color:#64b8e5;position:absolute;left:0;top:1px}
.principles-frontier{padding-left:14px;border-left:2px solid #475767;color:#a2afba;font-size:13px;line-height:1.8}
.principles-frontier>strong{display:block;color:#bac7d1;font-weight:500;margin-bottom:3px}
.principles-stage-sources{display:flex;align-items:center;gap:12px;margin-top:19px;font:10px var(--mono);color:var(--essay-blue)}
.principles-stage-sources>span{color:#96a9b7;font-size:9px;letter-spacing:1px}
.principles-stage-sources>a{padding:4px}
.principles-choice{padding-block:88px 95px;border-block:1px solid #324255;background:radial-gradient(ellipse at 10% 100%,#172f47 0,transparent 65%),#0d151f}
.principles-choice>.principles-wrap>.principles-kicker{margin-bottom:30px}
.principles-choice-grid{display:grid;grid-template-columns:1fr 1fr;gap:10%}
.principles-choice h2{font-size:clamp(56px,6.5vw,92px);line-height:.95}
.principles-choice h2 span{color:var(--essay-blue)}
.principles-choice .principles-lead{margin-top:23px;font-size:19px}
.principles-choice .principles-prose{font-size:15px}
.principles-choice p a{color:var(--essay-blue);text-decoration:underline;text-decoration-color:#35566d;text-underline-offset:4px}
.principles-choice .principles-button{margin-top:28px}
.principles-sources{padding-block:76px 70px}
.principles-sources h2{font-size:clamp(43px,4.3vw,62px)}
.principles-sources-intro{max-width:730px;margin-top:23px!important;color:var(--essay-muted);font-size:14px;line-height:1.8}
.principles-source-group{margin-top:43px}
.principles-source-group>h3{font:11px var(--mono);letter-spacing:1px;color:var(--essay-blue);padding-bottom:16px;border-bottom:1px solid var(--essay-line);text-transform:uppercase}
.principles-source-grid{list-style:none;padding:0;margin:0;display:grid;grid-template-columns:repeat(3,1fr);gap:0 28px}
.principles-source-grid li{min-width:0;border-bottom:1px solid var(--essay-line);transition:background-color .2s}
.principles-source-grid li:target{background:#142637;outline:1px solid #436781;outline-offset:6px}
.principles-source-grid a{display:flex;align-items:flex-start;gap:10px;padding:23px 0;height:100%}
.principles-source-grid a>div{flex:1;min-width:0}
.principles-source-grid a>span:last-child{font-size:14px;color:#6badcf}
.principles-source-number{font:9px var(--mono);color:#6e8798;line-height:1.9}
.principles-source-grid small{display:block;font:9px/1.8 var(--mono);color:#93a5b4}
.principles-source-grid strong{display:block;font-size:14px;line-height:1.5;font-weight:500;margin-block:8px 7px}
.principles-source-grid p{font-size:12px;color:var(--essay-muted);line-height:1.7}
.principles-editorial-note{font:10px/1.9 var(--mono);color:#8493a0;border-top:1px solid var(--essay-line);margin-top:50px!important;padding-top:22px}
@media(max-width:1100px){.principles-thesis-grid{gap:6%}
.principles-scale-cards>a{gap:14px;padding:25px 20px}
.principles-type{font-size:62px}
.principles-scale-cards strong{font-size:23px}
.principles-source-grid{grid-template-columns:repeat(2,1fr)}
.principles-guide-intro{gap:6%}}
@media(max-width:780px){.principles-wrap{width:88%}
.principles-thesis{padding-block:65px}
.principles-thesis-grid,.principles-guide-intro{grid-template-columns:1fr;gap:27px}
.principles-thesis h2 br:nth-child(2){display:none}
.principles-thesis h2{font-size:59px;max-width:560px}
.principles-prose{font-size:15px}
.principles-scale-guide{padding-bottom:60px}
.principles-scale-cards{grid-template-columns:1fr}
.principles-scale-cards>a{padding:22px;gap:25px}
.principles-scale-cards>a+a{border-left:0;border-top:1px solid var(--essay-line)}
.principles-scale-cards>a>div{display:grid;grid-template-columns:1fr 160px;column-gap:20px;flex:1}
.principles-scale-cards .principles-meta{grid-column:1}
.principles-scale-cards strong{grid-column:2;grid-row:1/4;align-self:center;margin:0}
.principles-scale-cards p{max-width:none}
.principles-type{min-width:59px}
.principles-scale-footnotes{gap:24px}
.principles-contents-grid{grid-template-columns:1fr 1fr}
.principles-reading-key{grid-template-columns:1fr;gap:10px}
.principles-stage-meta{margin-bottom:17px}
.principles-choice{padding-block:59px}
.principles-choice-grid{grid-template-columns:1fr;gap:32px}
.principles-choice h2{font-size:67px}
.principles-sources{padding-top:57px}}
@media(max-width:520px){.principles-thesis{padding-block:48px}
.principles-kicker{font-size:9px;letter-spacing:1.2px}
.principles-thesis h2{font-size:52px}
.principles-prose .principles-lead{font-size:19px}
.principles-scale-guide{padding-top:33px}
.principles-section-top{align-items:flex-start;margin-bottom:24px}
.principles-section-top>.principles-meta{display:none}
.principles-guide-intro h2{font-size:40px}
.principles-guide-intro>p{font-size:13px}
.principles-scale-cards>a{padding:22px 15px;gap:15px}
.principles-type{font-size:54px;min-width:43px}
.principles-scale-cards>a>div{display:block}
.principles-scale-cards strong{font-size:22px;margin-top:9px}
.principles-scale-cards h3{font-size:25px}
.principles-scale-footnotes{grid-template-columns:1fr;gap:18px}
.principles-page summary{font-size:12px}
.principles-contents-grid{grid-template-columns:1fr;gap:27px}
.principles-stage-meta{font-size:8px;gap:8px}
.principles-stage-subtitle{font-size:9px}
.principles-unlocks li{font-size:12px}
.principles-frontier{font-size:12px}
.principles-source-grid{grid-template-columns:1fr}
.principles-source-grid a{padding-block:21px}
.principles-source-group{margin-top:33px}
.principles-choice h2{font-size:60px}
.principles-sources h2{font-size:41px}
.principles-sources .principles-section-top>.principles-text-link{font-size:9px}
.principles-page [id]{scroll-margin-top:72px}}
@media(prefers-reduced-motion:reduce){html:has(.principles-page){scroll-behavior:auto}
.principles-page a,.principles-source-grid li{transition:none}}
/* Three overlapping frontiers, with a shared illustrated reading panel. */
.principles-icon-library{position:absolute;width:0;height:0;overflow:hidden}
.principles-explorer{position:relative;isolation:isolate;overflow:hidden;background:#080d13;border-bottom:1px solid var(--essay-line)}
.principles-backdrops,.principles-explorer-shade{position:absolute;inset:0;z-index:-2;pointer-events:none}
.principles-backdrops img{width:100%;height:100%;object-fit:cover;object-position:center;position:absolute;inset:0}
.principles-explorer-shade{z-index:-1;background:linear-gradient(90deg,#080e16ed 0%,#080e16a6 52%,#080e1655 100%),linear-gradient(0deg,#080d13 0%,#080d1326 50%,#080d139c 100%)}
.principles-explorer>.principles-wrap{padding-block:42px 30px}
.principles-explorer-heading{display:flex;align-items:flex-end;justify-content:space-between;gap:40px;margin-bottom:38px}
.principles-explorer-heading h1{font:800 clamp(42px,4.6vw,72px)/1 var(--display);letter-spacing:-.7px;margin-top:14px}
.principles-explorer-heading h1 span{color:var(--essay-blue)}
.principles-explorer-intro{max-width:355px;color:#b8c5ce;font-size:13px;line-height:1.7;flex-shrink:0}
.principles-explorer-intro a{display:inline-block;font:10px/1.7 var(--mono);color:var(--essay-blue);margin-top:12px;border-bottom:1px solid #486072}
.principles-explorer-intro a+a{margin-left:22px}
.principles-map-heading{display:flex;align-items:center;justify-content:space-between;gap:15px;border-top:1px solid #6b8ca04d;padding-top:17px;margin-bottom:11px}
.principles-map-hint,.principles-swipe-hint{font:9px/1.5 var(--mono);letter-spacing:1px;color:#8fa4b4}
.principles-swipe-hint{display:none}
.principles-map-scroll{overflow-x:auto;overscroll-behavior-x:contain;scrollbar-width:thin;scrollbar-color:#52758a #0c1822;padding:9px 5px 13px}
.principles-map-scroll:focus-visible{outline:1px solid var(--essay-blue);outline-offset:4px}
.principles-map{min-width:1010px;padding:0 8px}
.principles-track{display:flex;align-items:flex-start;gap:17px;height:94px}
.principles-track.track-1{width:68%}
.principles-track.track-2{width:62%;margin-left:29%}
.principles-track.track-3{width:35%;margin-left:65%;height:76px}
.principles-track-label{flex:0 0 65px;padding-top:3px}
.principles-track-label strong{display:block;font:600 28px/1 var(--display);color:#c0d5e3}
.principles-track-label span{display:block;font:8px/1.5 var(--mono);letter-spacing:1px;text-transform:uppercase;color:#91a6b5;margin-top:5px}
.principles-track-stops{position:relative;display:flex;justify-content:space-between;flex:1;min-width:0}
.principles-track-stops:before{content:"";position:absolute;top:22px;left:25px;right:25px;height:1px;background:linear-gradient(90deg,#69c6f99c,#86a2ba55)}
.principles-stop{width:60px;flex:0 0 60px;position:relative;display:flex;align-items:center;flex-direction:column;color:#a9bbc8;text-align:center;isolation:isolate}
.principles-stop-icon{display:grid;place-items:center;width:44px;height:44px;border:1px solid #456278;border-radius:50%;background:#0c1724f5;box-shadow:0 0 0 5px #0d182c30}
.principles-stop-icon svg{width:23px;height:23px;fill:none;stroke:currentColor;stroke-width:1.5;stroke-linecap:round;stroke-linejoin:round}
.principles-stop-label{font:9px/1.4 var(--mono);margin-top:9px;white-space:nowrap}
.principles-stop-horizon .principles-stop-icon{border-color:#77b6d2;box-shadow:0 0 0 4px #66cdff12}
.principles-stop[aria-selected="true"]{color:#8fdcff}
.principles-stop[aria-selected="true"] .principles-stop-icon{color:#061623;background:#73d3ff;border-color:#ace7ff;box-shadow:0 0 24px #46b6ff4d,0 0 0 5px #66cdff18}
.principles-stop:hover .principles-stop-icon{border-color:#b2e6ff;color:#cceeff}
.principles-stop[aria-selected="true"]:hover .principles-stop-icon{color:#061623}
.principles-now{font:7px/1 var(--mono);letter-spacing:.6px;color:#6ed7c2;position:absolute;top:77px;white-space:nowrap}
.principles-overlap-note{font-size:11px;line-height:1.7;color:#bbc7cf;padding-block:7px 22px}
.principles-overlap-note>span{color:var(--essay-blue);margin-right:6px}
.principles-overlap-note small{display:block;font:9px/1.7 var(--mono);color:#8a9eae;margin-left:18px;margin-top:3px}
.principles-stage-reader{border-top:1px solid #6b8ca04d;padding-top:28px}
.principles-stage-panel{display:grid;grid-template-columns:minmax(0,1.15fr) minmax(0,.85fr);gap:20px 9%;align-items:start;min-height:352px}
.principles-stage-panel:focus-visible{outline:1px solid var(--essay-blue);outline-offset:8px}
.principles-stage-story{max-width:650px}
.principles-stage-meta{margin-bottom:15px}
.principles-stage-story h2{font-size:clamp(34px,3.5vw,49px);line-height:1.02;margin-bottom:18px}
.principles-stage-paragraph{font-size:14px;line-height:1.8;color:#c3cdd5}
.principles-stage-paragraph+.principles-stage-paragraph{margin-top:12px}
.principles-stage-capabilities{padding:24px 26px;background:#0a1421ba;border:1px solid #617b9147;backdrop-filter:blur(12px)}
.principles-stage-capabilities .principles-unlocks{margin:0 0 20px;padding-top:0;border-top:0}
.principles-stage-capabilities h3{font:10px/1.7 var(--mono);letter-spacing:1px;color:var(--essay-blue)}
.principles-stage-capabilities .principles-frontier{font-size:12px}
.principles-scene-caption{grid-column:1/-1;font:8px/1.7 var(--mono);color:#91a5b5}
.principles-explorer-controls{display:flex;align-items:center;justify-content:space-between;border-top:1px solid #6b8ca033;margin-top:17px;padding-top:17px}
.principles-explorer-controls>div{display:flex;gap:10px}
.principles-explorer-controls button{min-height:40px;padding:9px 15px;border:1px solid #456078;background:#0c1927a6;color:#bde5ff;font:10px var(--mono);cursor:pointer}
.principles-explorer-controls button:hover:not(:disabled){background:#163148;border-color:#7fc9f4}
.principles-explorer-controls button:disabled{opacity:.35;cursor:default}
.principles-explorer-controls button:focus-visible{outline:2px solid var(--essay-blue);outline-offset:3px}
@media(min-width:1600px){.principles-stage-panel{min-height:330px}}
@media(max-width:1150px){.principles-explorer-heading{align-items:start;gap:25px}
.principles-explorer-heading h1 span{display:block}
.principles-explorer-intro{padding-top:32px;max-width:285px}
.principles-map-hint{display:none}
.principles-swipe-hint{display:block}
.principles-stage-panel{gap:20px 5%}}
@media(max-width:780px){.principles-explorer>.principles-wrap{padding-top:30px}
.principles-explorer-heading{display:block;margin-bottom:27px}
.principles-explorer-heading h1{font-size:56px}
.principles-explorer-heading h1 span{display:inline}
.principles-explorer-intro{padding-top:18px;max-width:none;font-size:12px}
.principles-explorer-intro p br{display:none}
.principles-stage-panel{grid-template-columns:1fr;min-height:0;gap:23px}
.principles-stage-story{max-width:none}
.principles-stage-capabilities{padding:21px}
.principles-backdrops img{height:min(100%,1000px);object-position:60% center}
.principles-explorer-shade{background:linear-gradient(90deg,#080e16db,#080e1673),linear-gradient(0deg,#080d13 5%,#080d1330 60%)}
.principles-map-heading .principles-meta{font-size:8px;letter-spacing:.6px}
.principles-swipe-hint{font-size:8px;letter-spacing:.3px}
.principles-overlap-note{font-size:10px}
.principles-overlap-note small{font-size:8px;margin-left:0}
.principles-stage-reader{padding-top:23px}
.principles-scene-caption{font-size:8px}}
@media(max-width:520px){.principles-explorer-heading h1{font-size:49px}
.principles-explorer-heading h1 span{display:block}
.principles-map-heading{align-items:start}
.principles-map-heading .principles-meta{max-width:150px}
.principles-swipe-hint{max-width:98px;text-align:right}
.principles-stage-story h2{font-size:37px}
.principles-stage-paragraph{font-size:13px;line-height:1.85}
.principles-explorer-controls button{padding-inline:11px;font-size:9px}
.principles-explorer-controls .principles-meta{font-size:8px}}


/* A final ambition below K3; not an additional Kardashev type. */
.principles-track.track-4{width:35%;margin-left:65%;height:94px;padding-top:8px}
.track-4 .principles-track-label{display:none}
.track-4 .principles-track-stops:before{display:none}
.track-4 .principles-stop{width:100%;flex:1;flex-direction:row-reverse;justify-content:flex-start;gap:15px;padding:11px 8px 11px 16px;border:0;background:transparent;text-align:right}
.track-4 .principles-stop-label{margin:0;white-space:normal;font-size:11px;line-height:1.5;color:#d0c1f0}
.track-4 .principles-stop-icon{flex-shrink:0;border-color:#9c86c5;color:#d0c1f0}
.track-4 .principles-stop:focus-visible{outline:none}
.track-4 .principles-stop:focus-visible .principles-stop-icon{outline:2px solid var(--essay-blue);outline-offset:5px}
.track-4 .principles-stop[aria-selected="true"] .principles-stop-icon{background:#c5adff;color:#171126;box-shadow:0 0 25px #bb9dff50}
.principles-stage-sources{flex-wrap:wrap}
#saving-the-universe .principles-unlocks li+li{margin-top:16px}