/* Night classroom. Reuses the site's local Gelasio/Inter typography and shell. */
.sky-page { --sky-bg:#0b191e; --sky-panel:#102126; --sky-ink:#e9eee5; --sky-muted:#a6bbb9; --sky-gold:#e0b67e; --sky-rule:#385054; --sky-control:#182e33; max-width:1400px; margin:0 auto; padding:0 var(--gutter); }
.page-main > .sky-page { width:min(100%,calc(var(--max) + 2 * var(--gutter))); max-width:none; }
.sky-masthead { display:grid; grid-template-columns:1.25fr 1fr; align-items:end; gap:50px; padding:54px 0 44px; }
.sky-eyebrow { text-transform:uppercase; font:600 10px/1.5 var(--sans); letter-spacing:.17em; margin:0 0 12px; }
.sky-masthead h1 { font:500 clamp(52px,6.4vw,88px)/1.02 var(--serif); letter-spacing:-.045em; }
.sky-masthead h1 em { font-weight:400; color:var(--clay); }
.sky-intro { max-width:390px; margin:0 0 3px auto; }
.sky-intro>p:first-child { font:400 20px/1.55 var(--sans); }
.sky-small { font-size:13px; line-height:1.7; color:var(--ink-2); }
.sky-text-link { font-size:14px; font-weight:600; }
.sky-observatory { background:var(--sky-bg); color:var(--sky-ink); border:1px solid var(--sky-rule); scroll-margin-top:20px; }
.sky-stage-header { display:flex; align-items:center; justify-content:space-between; gap:24px; padding:24px 30px; border-bottom:1px solid var(--sky-rule); }
.sky-stage-header h2 { font:400 25px/1.3 var(--serif); letter-spacing:-.02em; }
.sky-stage-header .sky-eyebrow { color:var(--sky-muted); margin:0 0 5px; font-size:9px; }
.sky-display-actions { display:flex; align-items:center; gap:20px; }
.sky-display-actions>a { font-size:12px; color:var(--sky-muted); }
.sky-observatory button, .sky-print, .sky-pagination button { min-height:42px; border:1px solid var(--sky-rule); border-radius:3px; padding:9px 13px; background:transparent; color:inherit; cursor:pointer; font:500 12px/1.3 var(--sans); }
.sky-observatory button:hover { background:var(--sky-control); border-color:var(--sky-muted); }
.sky-observatory button[aria-pressed=true] { color:var(--sky-gold); border-color:var(--sky-gold); }
.sky-observatory button:disabled, .sky-pagination button:disabled { opacity:.45; cursor:default; }
.sky-observatory :focus-visible { outline-color:var(--sky-gold); }
.sky-workbench { display:grid; grid-template-columns:minmax(0,1fr) 344px; }
.sky-view { padding:22px 26px 24px; min-width:0; }
.sky-view-title { display:flex; justify-content:space-between; gap:12px; font:500 11px/1.5 var(--sans); color:var(--sky-muted); }
#light-label::before { content:''; display:inline-block; height:6px; width:6px; border-radius:50%; background:var(--sky-gold); margin-right:8px; vertical-align:1px; }
.sky-plot { width:min(100%,690px); aspect-ratio:1; margin:0 auto; }
.sky-plot canvas, .sky-plot>img { display:block; width:100%; height:100%; object-fit:contain; }
.sky-plot canvas { touch-action:pan-y; cursor:crosshair; }
.sky-plot canvas:focus-visible { outline-offset:-3px; }
.sky-view-caption { display:flex; align-items:center; justify-content:space-between; gap:12px; margin-top:3px; color:var(--sky-muted); }
.sky-view-caption p { font-size:11px; line-height:1.8; margin:0; }
.sky-view-mark { color:var(--sky-gold); font-size:25px; }
.sky-limit { border-top:1px solid var(--sky-rule); margin:18px 0 0; padding-top:14px; font:400 12px/1.65 var(--sans); color:var(--sky-muted); }
.sky-controls-column { border-left:1px solid var(--sky-rule); background:var(--sky-panel); padding:25px 24px; }
.sky-controls-column label { display:block; font-size:11px; font-weight:500; margin:0 0 5px; color:var(--sky-muted); }
.sky-controls-column input:not([type=checkbox]), .sky-controls-column select, #share-url { font:400 13px/1.4 var(--sans); width:100%; min-width:0; min-height:43px; border:1px solid var(--sky-rule); border-radius:3px; padding:8px; color:var(--sky-ink); background:var(--sky-control); color-scheme:dark; margin-top:7px; }
.sky-season-buttons { display:grid; grid-template-columns:repeat(4,1fr); gap:4px; margin:0 0 18px; }
.sky-season-buttons button { padding:8px 2px; font-size:11px; min-height:36px; }
.sky-date-fields { display:grid; grid-template-columns:minmax(0,1.2fr) minmax(0,.85fr); gap:10px; }
.sky-help { color:var(--sky-muted); font-size:10px; line-height:1.6; margin:3px 0 12px; }
.sky-utc { color:var(--sky-muted); font:400 10px/1.5 var(--mono); letter-spacing:.01em; margin:8px 0 14px; text-align:center; }
.sky-observatory .sky-primary { background:var(--sky-gold); color:#142125; width:100%; display:flex; align-items:center; justify-content:space-between; border-color:var(--sky-gold); }
.sky-observatory .sky-primary:hover { background:#f2cca0; color:#142125; }
.sky-error { color:#ffd2b3; font-size:12px; margin:6px 0 10px; }
.sky-error:empty { display:none; }
.sky-time-actions { display:grid; grid-template-columns:1fr 1.25fr 1fr; gap:5px; }
.sky-time-actions button { padding:8px 4px; font-size:11px; }
#motion-note { margin-top:7px; }
.sky-direction-row { display:grid; grid-template-columns:.72fr 1.28fr; gap:10px; margin-top:20px; }
.sky-controls-column .sky-check { display:flex; align-items:center; flex-wrap:wrap; gap:7px; font-size:11px; margin:10px 0 20px; }
.sky-check input { accent-color:var(--sky-gold); width:16px; height:16px; margin:0; }
.sky-check span { color:var(--sky-muted); font-size:10px; }
.sky-object-picker { border-top:1px solid var(--sky-rule); padding-top:18px; }
.sky-selected { margin-top:22px; }
.sky-selected-heading { display:flex; align-items:center; gap:13px; }
.sky-selected h3 { font:400 30px/1.1 var(--serif); color:var(--sky-gold); }
.sky-star-symbol { font-size:30px; color:var(--sky-gold); }
#selected-position { font-size:11px; margin:5px 0 0; color:var(--sky-muted); }
.sky-selected h4 { font-size:12px; margin:17px 0 7px; font-weight:500; }
#selected-story { font-size:12px; line-height:1.75; color:var(--sky-muted); margin-bottom:9px; }
#selected-source a:hover,.sky-observatory a:hover { color:var(--sky-gold); }
.sky-celestial-strip { border-top:1px solid var(--sky-rule); display:grid; grid-template-columns:1fr 1fr 1fr; padding:20px 30px; gap:24px; }
.sky-celestial-strip>div:not(:first-child) { padding-left:24px; border-left:1px solid var(--sky-rule); }
.sky-celestial-strip .sky-eyebrow { display:block; margin:0 0 5px; color:var(--sky-muted); font-size:9px; }
.sky-celestial-strip strong { display:block; font:500 14px/1.5 var(--sans); }
.sky-celestial-strip span:not(.sky-eyebrow) { display:block; font-size:11px; line-height:1.5; color:var(--sky-muted); margin-top:4px; }
.sky-share button { min-height:36px; padding:5px 0; border:0; text-align:left; }
.sky-share button span { display:inline!important; color:var(--sky-gold)!important; }
#share-copy { font-size:11px; margin-top:10px; }
.sky-status { padding:0 30px; margin:0; font-size:12px; line-height:1.8; color:var(--sky-gold); }
.sky-status:not(:empty) { padding-top:10px; padding-bottom:14px; border-top:1px solid var(--sky-rule); }
.sky-loading { padding:18px 0; font-size:15px; line-height:1.7; }
.sky-loading button, .sky-loading a { display:block; margin-top:20px; }
.sky-loading a { font-size:13px; }
.sky-scene-list { border:1px solid var(--rule-2); border-top:0; margin:0 0 90px; }
.sky-scene-list summary { cursor:pointer; padding:22px 28px; font:500 16px/1.5 var(--serif); }
.sky-scene-list summary .sky-small { margin-left:18px; font-family:var(--sans); font-weight:400; }
.sky-list-content { padding:0 28px 25px; }
.sky-list-filters { display:grid; grid-template-columns:1fr 1fr; gap:20px; max-width:700px; margin:20px 0; }
.sky-list-filters label { font-size:12px; }
.sky-list-filters input, .sky-list-filters select { display:block; width:100%; min-height:44px; padding:8px 12px; border:1px solid var(--rule-2); border-radius:3px; background:var(--card); color:var(--ink); font:inherit; margin-top:6px; }
.sky-table-wrap { overflow:auto; }
.sky-table-wrap table { border-collapse:collapse; font-size:13px; width:100%; text-align:left; }
.sky-table-wrap caption { text-align:left; font-size:12px; padding:0 0 15px; }
.sky-table-wrap th,.sky-table-wrap td { border-bottom:1px solid var(--rule); padding:10px 12px; white-space:nowrap; }
.sky-table-wrap th:first-child,.sky-table-wrap td:first-child { padding-left:0; }
.sky-table-wrap button { border:0; padding:5px 0; min-height:32px; background:none; text-decoration:underline; text-underline-offset:3px; cursor:pointer; font-size:13px; }
.sky-pagination { display:flex; justify-content:space-between; align-items:center; gap:15px; margin:20px 0; }
.sky-pagination button { border-color:var(--rule-2); }
.sky-pagination span { font-size:12px; }
.sky-guide-header { display:grid; grid-template-columns:1.1fr 1fr; gap:65px; align-items:end; margin-bottom:34px; }
.sky-guide h2,.sky-before-you-go h2,.sky-methods h2 { font:400 clamp(34px,4.5vw,56px)/1.12 var(--serif); letter-spacing:-.035em; }
.sky-guide-header>div:last-child { max-width:450px; }
.sky-print { border-color:var(--rule-2); color:var(--ink); padding:10px 16px; }
.sky-pdf-link { display:inline-block; margin:10px 0 0 15px; font-size:12px; }
.sky-lesson-nav { display:flex; flex-wrap:wrap; gap:10px 22px; padding:20px 0 27px; border-top:1px solid var(--rule-2); }
.sky-lesson-nav a { font-size:12px; text-decoration:none; }
.sky-lesson-nav a span { font-family:var(--mono); font-size:10px; color:var(--clay); margin-right:4px; }
.sky-static-charts { display:grid; grid-template-columns:1fr 1fr; gap:24px; }
.sky-static-charts figure { margin:0; }
.sky-static-charts img { background:var(--sky-bg); width:100%; display:block; }
.sky-static-charts figcaption { padding-top:13px; font-size:12px; }
.sky-static-charts strong,.sky-static-charts span { display:block; }
.sky-static-charts strong { color:var(--ink-2); }
.sky-static-charts span { margin-top:3px; color:var(--ink-2); font-size:11px; }
.sky-static-caption { font-size:11px; color:var(--ink-2); max-width:780px; margin:18px 0 45px; }
.sky-lesson { display:grid; grid-template-columns:70px minmax(0,1fr) minmax(230px,.72fr); column-gap:30px; padding:38px 0; border-top:1px solid var(--rule-2); scroll-margin-top:25px; }
.sky-lesson-number { font:400 42px/1 var(--serif); color:var(--clay); letter-spacing:-.05em; }
.sky-lesson .sky-eyebrow { color:var(--clay); font-size:9px; margin-bottom:12px; }
.sky-lesson h3 { font:400 31px/1.18 var(--serif); letter-spacing:-.025em; margin-bottom:14px; }
.sky-lesson-deck { font-weight:500; font-size:14px; margin-bottom:18px; }
.sky-lesson-body>p:not(.sky-eyebrow):not(.sky-lesson-deck) { font-size:14px; line-height:1.85; max-width:580px; }
.sky-try { background:var(--paper-2); border-top:2px solid var(--clay); padding:23px; align-self:start; margin:27px 0 0 25px; font-size:13px; line-height:1.8; }
.sky-try h4 { font:500 11px/1.5 var(--sans); text-transform:uppercase; letter-spacing:.1em; margin:0 0 9px; }
.sky-try .sky-notice { color:var(--ink-2); font-size:12px; border-top:1px solid var(--rule); padding-top:12px; }
.sky-try a { display:inline-block; font-size:12px; font-weight:600; margin-right:15px; margin-top:5px; }
.sky-lesson-sources { font-size:11px; color:var(--ink-2); }
.sky-before-you-go { display:grid; grid-template-columns:.8fr 1.2fr; gap:18px 70px; padding:45px 0; border-block:1px solid var(--rule-2); margin:40px 0 65px; }
.sky-before-you-go>.sky-eyebrow { grid-column:1/-1; margin:0; color:var(--clay); }
.sky-before-you-go>div { max-width:680px; font-size:14px; }
.sky-before-you-go>div>p:last-child { display:flex; gap:25px; flex-wrap:wrap; font-size:12px; font-weight:600; }
.sky-methods { display:grid; grid-template-columns:.8fr 1.2fr; gap:70px; margin-bottom:80px; }
.sky-methods h2 { font-size:38px; }
.sky-methods>div:last-child { font-size:13px; line-height:1.85; }
.sky-methods details { border-top:1px solid var(--rule-2); padding:15px 0; }
.sky-methods summary { font-weight:600; cursor:pointer; }
.sky-methods details p { margin-top:14px; }
.sky-sources { padding-left:18px; font-size:11px; }
.sky-sources li { margin:10px 0; }
/* Red mode covers the entire document, including the inherited shell. */
html.sky-red { color-scheme:dark; --paper:#130606; --paper-2:#210b0b; --paper-3:#2d1010; --card:#210b0b; --ink:#df9986; --ink-2:#c47f70; --ink-3:#be786a; --rule:#542825; --rule-2:#70362f; --clay:#ec9b7e; --focus:#faad8d; }
.sky-red .sky-page { --sky-bg:#100404; --sky-panel:#190808; --sky-ink:#e7a18d; --sky-muted:#ca8474; --sky-gold:#eea087; --sky-rule:#66332e; --sky-control:#260c0c; }
.sky-red .brand img,.sky-red .sky-static-charts img,.sky-red #sky-poster { filter:grayscale(1) sepia(1) saturate(3) hue-rotate(320deg) brightness(.65); }
.sky-red .sky-observatory .sky-primary { background:#70362f; color:#ffc0a6; }
.sky-red .sky-error { color:#f3a38d; }
.sky-red .site-footer { background:var(--paper-2); color:var(--ink); }
.sky-red .site-nav a:hover { color:var(--ink); }
@media(min-width:1450px) { .sky-page { max-width:1440px; } .sky-workbench { grid-template-columns:minmax(0,1fr) 370px; } }
@media(max-width:1050px) { .sky-workbench { grid-template-columns:minmax(0,1fr) 310px; } .sky-controls-column { padding:22px 18px; } .sky-view { padding:22px 18px; } .sky-lesson { grid-template-columns:44px 1fr .8fr; gap:20px; } .sky-try { margin-left:0; } .sky-display-actions { flex-direction:column; gap:8px; align-items:flex-end; } }
@media(max-width:760px) { .sky-masthead { grid-template-columns:1fr; gap:25px; padding:34px 0; } .sky-intro { margin:0; max-width:500px; } .sky-intro>p:first-child { font-size:17px; } .sky-masthead h1 { font-size:60px; } .sky-stage-header { padding:20px; gap:10px; } .sky-stage-header h2 { font-size:21px; } .sky-display-actions>a { display:none; } .sky-workbench { grid-template-columns:1fr; } .sky-view { padding:20px 14px; } .sky-controls-column { border-left:0; border-top:1px solid var(--sky-rule); padding:25px 22px; } .sky-celestial-strip { padding:20px; gap:20px; grid-template-columns:1fr 1fr; } .sky-celestial-strip>div:nth-child(2) { padding-left:15px; } .sky-celestial-strip .sky-share { grid-column:1/-1; padding:14px 0 0; border-left:0; border-top:1px solid var(--sky-rule); } .sky-scene-list { margin-bottom:55px; } .sky-scene-list summary { padding:19px; } .sky-scene-list summary .sky-small { display:block; margin:6px 0 0; font-size:11px; } .sky-list-content { padding:0 18px 20px; } .sky-list-filters { gap:12px; grid-template-columns:1fr; } .sky-guide-header { grid-template-columns:1fr; gap:22px; } .sky-static-charts { gap:14px; } .sky-static-charts figcaption { font-size:10px; } .sky-static-charts span { font-size:9px; } .sky-lesson { grid-template-columns:37px minmax(0,1fr); gap:18px; padding:30px 0; } .sky-lesson-number { font-size:33px; } .sky-lesson h3 { font-size:28px; } .sky-try { grid-column:2; margin:0; padding:18px; } .sky-before-you-go,.sky-methods { grid-template-columns:1fr; gap:24px; } .sky-before-you-go { margin-top:20px; margin-bottom:45px; } .sky-methods { margin-bottom:50px; } }
@media(max-width:370px) { .sky-stage-header { align-items:start; } .sky-stage-header h2 { font-size:18px; } .sky-stage-header .sky-eyebrow { font-size:8px; } .sky-display-actions button { padding:8px; font-size:10px; } .sky-celestial-strip { grid-template-columns:1fr; } .sky-celestial-strip>div:nth-child(2) { border-left:0; border-top:1px solid var(--sky-rule); padding:12px 0 0; } }
@media(max-width:560px) { .sky-static-charts { grid-template-columns:1fr; gap:28px; } .sky-static-charts figcaption { font-size:12px; } .sky-static-charts span { font-size:11px; } }
@media(prefers-reduced-motion:reduce) { html { scroll-behavior:auto; } .sky-page *, .sky-page *::before, .sky-page *::after { animation:none!important; transition:none!important; } }
@media print {
  @page { margin:16mm; }
  html.sky-red,html { --paper:#fff; --paper-2:#f4f4f4; --ink:#111; --ink-2:#333; --clay:#333; --rule:#ccc; --rule-2:#aaa; color-scheme:light; scroll-behavior:auto; }
  body { background:#fff!important; color:#111!important; font-size:11pt; }
  .site-header,.site-footer,.skip,.sky-observatory,.sky-scene-list,.sky-lesson-nav,.sky-print,.sky-pdf-link,.sky-intro a,.sky-try>a { display:none!important; }
  .sky-page { max-width:none; padding:0; }
  .sky-masthead { display:block; padding:0 0 20px; }
  .sky-masthead h1 { font-size:38pt; }
  .sky-masthead h1 br { display:none; }
  .sky-intro { max-width:none; margin-top:15px; }
  .sky-intro>p:first-child { font-size:11pt; }
  .sky-guide-header { display:block; margin-top:20px; }
  .sky-guide h2 { font-size:26pt; }
  .sky-guide h2 br { display:none; }
  .sky-static-charts { grid-template-columns:1fr 1fr; gap:15px; break-inside:avoid; }
  .sky-static-charts img { filter:none!important; print-color-adjust:exact; }
  .sky-lesson { break-inside:avoid; display:grid; grid-template-columns:32px 1fr; gap:16px; padding:20px 0; }
  .sky-lesson h3 { font-size:20pt; }
  .sky-lesson p { font-size:10pt!important; }
  .sky-try { grid-column:2; margin:0; padding:10px 0; background:none; }
  .sky-before-you-go,.sky-methods { display:block; margin:25px 0; padding:20px 0; }
  .sky-methods h2 { font-size:22pt; margin-bottom:15px; }
  .sky-methods details { display:block; }
  .sky-methods details::details-content { content-visibility:visible; height:auto; overflow:visible; }
  .sky-methods details > :not(summary) { display:block!important; }
  .sky-methods summary { list-style:none; }
  .sky-sources li { break-inside:avoid; }
  a { color:#111!important; }
  a[href^="https:"]::after { content:" (" attr(href) ")"; font-size:8pt; overflow-wrap:anywhere; }
}