:root{color-scheme:light;--paper:#f5f2e9;--ink:#242922;--muted:#73756b;--line:#d8d9cd;--accent:#b95030;--body:20px;--serif:"Noto Serif CJK SC","Source Han Serif SC","Songti SC",SimSun,serif;--sans:Arial,"Noto Sans CJK SC","PingFang SC","Microsoft YaHei",sans-serif}*{box-sizing:border-box}html{scroll-behavior:smooth;scroll-padding-top:105px}body{margin:0;background:var(--paper);color:var(--ink);font-family:var(--sans);-webkit-font-smoothing:antialiased}a{color:inherit;text-decoration:none}button{font:inherit;cursor:pointer;color:inherit}a:focus-visible,button:focus-visible,summary:focus-visible{outline:2px solid var(--accent);outline-offset:6px}::selection{background:#e7c7ad}.skip{position:fixed;left:20px;top:-100px;z-index:100;background:var(--ink);color:var(--paper);padding:15px}.skip:focus{top:15px}.masthead{height:90px;margin:0 auto;padding:0 5.3%;border-bottom:1px solid var(--line);display:flex;align-items:center;gap:30px}.brand{display:flex;align-items:center;gap:13px;font:600 24px/1 var(--serif);letter-spacing:.12em}.brand-sun{width:23px;height:23px;border:1px solid var(--accent);border-radius:50%;position:relative}.brand-sun:after{content:"";position:absolute;width:9px;height:9px;border-radius:50%;background:var(--accent);inset:6px}.mast-caption{font:12px/1.5 var(--sans);letter-spacing:.14em;color:var(--muted)}.mast-index{margin-left:auto;font-size:12px;letter-spacing:.08em}.mast-index span{margin-left:24px;font-size:18px}.eyebrow{font:11px/1.6 var(--sans);letter-spacing:.18em;display:flex;align-items:center;gap:30px}.eyebrow>span{font-size:11px;letter-spacing:.1em;color:var(--muted)}.home .layout{max-width:1320px;margin:auto;padding:0 5.3%}.book-intro{display:grid;grid-template-columns:1.15fr 1fr;gap:60px;padding:62px 0 58px;border-bottom:1px solid var(--ink);align-items:center}.intro-copy h1{font:500 clamp(70px,7.8vw,106px)/1.2 var(--serif);letter-spacing:.12em;margin:21px 0 16px}.title-dot{color:var(--accent);letter-spacing:0}.intro-subtitle{font:400 23px/1.5 var(--serif);letter-spacing:.19em}.intro-note{font-size:13px;line-height:1.9;color:var(--muted);margin:24px 0}.start-reading{font-size:12px;display:inline-flex;align-items:center;gap:48px;border-bottom:1px solid var(--accent);padding:9px 0;color:var(--accent)}.start-reading span{font-size:20px}.solar-plate{height:310px;position:relative;overflow:hidden;background:#eee9db;border:1px solid #d9d2c1}.plate-label{position:absolute;top:20px;left:22px;font-size:9px;letter-spacing:.2em;color:#696a5c}.sun-disc{position:absolute;width:205px;height:205px;border-radius:50%;top:50%;left:50%;transform:translate(-50%,-50%);background:#be5937;box-shadow:inset -18px -2px 0 #ac472b}.sun-disc:after{content:"";position:absolute;inset:8px;border-radius:50%;background:repeating-linear-gradient(0deg,transparent 0 4px,#f5d5a930 4px 5px);mix-blend-mode:soft-light}.orbit{position:absolute;border:1px solid #a29d8b;border-radius:50%;width:292px;height:292px;top:50%;left:50%;transform:translate(-50%,-50%)}.orbit-two{width:390px;height:390px;border-color:#c5beac}.orbit-one:after{content:"";position:absolute;width:7px;height:7px;left:31px;top:47px;background:var(--ink);border-radius:50%}.crosshair{position:absolute;color:#8d8b7c;font:20px/1 monospace}.cross-one{top:42px;right:28px}.cross-two{bottom:43px;left:30px}.plate-caption{position:absolute;bottom:17px;right:20px;font-size:10px;letter-spacing:.18em;color:#737363;background:#eee9db;padding:4px 0 4px 10px}.contents{display:grid;grid-template-columns:220px 1fr;gap:54px;padding:42px 0 20px}.contents-label{padding-top:5px}.contents-label .eyebrow{color:var(--accent)}.contents-label h2{font:500 25px/1.5 var(--serif);letter-spacing:.08em;margin:13px 0}.contents-label p{font-size:12px;color:var(--muted);line-height:1.8}.edition-note{font-size:11px;line-height:1.9;color:var(--muted);border-top:1px solid var(--line);padding-top:20px;margin-top:34px;max-width:175px}.chapterlist{list-style:none;margin:0;padding:0}.chapterlist li{border-bottom:1px solid var(--line)}.chapterlist a,.pending-entry{display:grid;grid-template-columns:38px minmax(0,1fr) 45px;gap:20px;align-items:start;padding:27px 0;transition:background .18s,color .18s}.chapterlist li:first-child>div{padding-top:7px;padding-bottom:25px}.chapter-number{font:italic 24px/1.3 Georgia,serif;color:var(--accent)}.chapterlist h3{font:500 clamp(18px,1.85vw,23px)/1.65 var(--serif);margin:-4px 0 10px;letter-spacing:.015em}.entry-meta{font-size:10px;line-height:1.8;color:var(--muted);letter-spacing:.04em}.meta-separator{padding:0 9px;color:#b2b3a6}.entry-arrow{font-size:23px;justify-self:end;transition:transform .18s}.chapterlist a:hover{color:var(--accent)}.chapterlist a:hover .entry-arrow{transform:translate(3px,-3px)}.unavailable{color:#72766b}.unavailable .chapter-number{color:#8a8c7f}.updating-mark{font-size:10px;white-space:nowrap;justify-self:end;line-height:2.5}.contents-end{display:flex;align-items:center;justify-content:center;gap:14px;font:12px/1.6 var(--serif);letter-spacing:.15em;color:var(--muted);padding:42px 0 28px}.tiny-sun{color:var(--accent);font-size:23px}.site-footer{margin:30px 5.3% 0;border-top:1px solid var(--ink);padding:30px 0 40px;display:flex;align-items:center;gap:35px}.site-footer>.brand{font-size:21px;gap:0}.footer-dot{color:var(--accent)}.site-footer>span{font-size:9px;letter-spacing:.12em;line-height:1.9;color:var(--muted)}.site-footer>a:last-child{margin-left:auto;font-size:11px;color:var(--muted)}.reading .masthead{position:sticky;top:0;background:var(--paper);z-index:20;height:76px}.reading .layout{display:grid;grid-template-columns:220px minmax(0,740px);gap:76px;max-width:1200px;margin:auto;padding:46px 35px 70px}.sidebar{position:sticky;top:113px;align-self:start;max-height:calc(100vh - 138px);overflow:auto;scrollbar-width:thin}.sidebar details{border-bottom:1px solid var(--line);margin:0 0 25px;padding-bottom:22px}.sidebar summary{font-size:11px;letter-spacing:.1em;cursor:pointer;line-height:1.6;margin-bottom:19px}.sidebar summary>span{float:right;color:var(--muted);font-size:10px}.sidebar ol{list-style:none;margin:0;padding:0}.sidebar li{font-size:12px;line-height:1.9;margin:0 0 15px}.book-nav a,.book-nav .pending{display:grid;grid-template-columns:20px 1fr;gap:9px}.nav-number{color:#8c8d7f;font-family:Georgia,serif}.sidebar a{color:#72766b}.sidebar a:hover,.sidebar a.current,.sidebar a.active{color:var(--accent)}.sidebar .current{font-weight:600}.sidebar .pending{color:#929487}.pending small{grid-column:2;font-size:10px;margin-top:-9px}.section-nav a{display:block;padding-left:12px;border-left:1px solid transparent}.section-nav a.active{border-left-color:var(--accent)}.chapterhead{margin:0 0 48px;padding:0 0 27px;border-bottom:1px solid var(--line)}.back-link{display:inline-block;color:var(--muted);font-size:11px;margin-bottom:42px}.chapterhead .eyebrow{color:var(--accent);margin-bottom:16px}.chapterhead h1{font:500 clamp(30px,3.4vw,44px)/1.55 var(--serif);letter-spacing:.025em;margin:0 0 30px;text-wrap:balance}.chapter-meta{display:flex;align-items:end;justify-content:space-between;gap:20px}.meta{font-size:11px;line-height:1.9;color:var(--muted)}.meta>span{padding:0 9px;color:#a2a495}.tools{display:flex;align-items:center;gap:0;white-space:nowrap}.tools>span{font-size:10px;color:var(--muted);margin-right:12px}.tools button{font-size:12px;min-width:42px;height:35px;border:1px solid var(--line);background:none}.tools button+button{border-left:0}.tools button:hover{background:#eae6da}.tools button:disabled{color:#b0b1a8;cursor:default}.prose{font:var(--body)/2.05 var(--serif);overflow-wrap:break-word;line-break:strict}.prose p{margin:0 0 1.45em;text-align:justify}.prose h2{font:600 1.2em/1.7 var(--serif);margin:2.8em 0 1.35em;scroll-margin-top:0;break-after:avoid}.prose section:first-child h2{margin-top:0}.prose section+section{margin-top:65px}.prose section+section:before{content:"";display:block;width:30px;border-top:2px solid var(--accent)}.reading main{min-width:0}.reading main>footer{font-size:11px;line-height:1.9;color:var(--muted);border-top:1px solid var(--line);margin-top:65px;padding-top:20px}.pager{display:flex;justify-content:space-between;gap:30px;margin-top:40px;font-size:13px}.pager a{border-bottom:1px solid var(--ink);padding:12px 0;min-width:100px}.pager a:last-child{margin-left:auto;text-align:right}.reading-progress{position:fixed;top:0;left:0;width:0;height:3px;background:var(--accent);z-index:40}.home .reading-progress{display:none}.menu-toggle,.menu-close,.drawer-head,.nav-shade{display:none}.notice{font-size:12px;color:var(--muted);margin-bottom:20px}figure{margin:2em 0}figure img{width:100%;height:auto}figcaption{font:12px/1.8 var(--sans);color:var(--muted)}figcaption .credit{display:block}
@media(max-width:1100px){.reading .layout{gap:45px;grid-template-columns:190px minmax(0,700px);padding-left:28px;padding-right:28px}.contents{grid-template-columns:170px 1fr;gap:35px}.book-intro{gap:35px}.solar-plate{height:295px}.chapter-meta{flex-wrap:wrap}}
@media(max-width:880px){.masthead{height:74px;padding:0 6%;gap:20px}.mast-caption{display:none}.brand{font-size:22px}.book-intro{padding-top:40px;gap:30px}.intro-copy h1{font-size:70px}.intro-subtitle{font-size:19px}.intro-note{font-size:12px}.eyebrow{gap:17px;font-size:9px}.eyebrow>span{font-size:9px}.solar-plate{height:275px}.sun-disc{width:170px;height:170px}.orbit-one{width:240px;height:240px}.orbit-two{width:325px;height:325px}.contents{grid-template-columns:140px 1fr;gap:30px}.chapterlist a,.pending-entry{gap:13px;grid-template-columns:28px minmax(0,1fr) 32px}.chapterlist h3{font-size:18px}.entry-meta{font-size:9px}.meta-separator{padding:0 4px}.reading .masthead{height:66px}.reading .mast-index{display:none}.menu-toggle{display:block;margin-left:auto;border:0;background:none;font-size:12px;padding:10px 0 10px 15px}.menu-toggle span{padding-left:12px}.reading .layout{display:block;padding:30px 7% 50px;max-width:780px}.sidebar{position:fixed;left:0;top:0;bottom:0;width:min(340px,85vw);max-height:none;padding:24px 25px;background:var(--paper);z-index:60;transform:translateX(-105%);visibility:hidden;transition:transform .2s,visibility .2s}.nav-open .sidebar{visibility:visible;transform:translateX(0)}.nav-shade{position:fixed;inset:0;background:#22282066;border:0;z-index:55;cursor:default}.nav-open .nav-shade{display:block}.drawer-head{display:flex;align-items:center;justify-content:space-between;border-bottom:1px solid var(--line);padding-bottom:20px;margin-bottom:25px;font:20px var(--serif)}.menu-close{display:block;border:0;background:none;font-size:28px;padding:0 5px}.sidebar li{font-size:13px;margin-bottom:18px}.sidebar summary{font-size:12px}.back-link{margin-bottom:30px}.chapterhead h1{font-size:34px}.prose{--body:19px}.nav-open{overflow:hidden}.chapter-meta{flex-wrap:nowrap}.site-footer{margin-left:6%;margin-right:6%}}
@media(max-width:600px){.home .layout{padding:0 6%}.mast-index{font-size:11px}.mast-index span{margin-left:10px}.book-intro{grid-template-columns:1fr;gap:30px;padding:34px 0 31px}.intro-copy h1{font-size:76px;margin-top:20px;margin-bottom:15px}.intro-subtitle{font-size:21px}.intro-note{font-size:12px;margin:20px 0 12px}.start-reading{gap:35px}.solar-plate{height:178px}.sun-disc{width:145px;height:145px}.orbit-one{width:197px;height:197px}.orbit-two{width:270px;height:270px}.plate-label{left:15px;top:15px;font-size:8px}.plate-caption{font-size:9px;bottom:10px;right:13px}.cross-one{top:30px;right:23px}.cross-two{bottom:25px;left:23px}.contents{display:block;padding-top:30px}.contents-label{display:grid;grid-template-columns:1fr 1fr;align-items:center;border-bottom:1px solid var(--line);padding-bottom:22px}.contents-label .eyebrow{grid-column:1/-1;font-size:9px}.contents-label h2{font-size:24px;margin:9px 0 0}.contents-label p{font-size:11px;text-align:right;margin:9px 0 0}.edition-note{grid-column:1/-1;border:0;margin:13px 0 0;padding:0;max-width:none;font-size:10px;line-height:1.7}.edition-note br{display:none}.chapterlist li:first-child>div{padding-top:24px;padding-bottom:24px}.chapterlist a,.pending-entry{padding:25px 0;grid-template-columns:25px minmax(0,1fr) 24px;gap:11px}.chapterlist h3{font-size:18px;line-height:1.65;margin-top:-2px;margin-bottom:10px}.chapter-number{font-size:21px}.entry-arrow{font-size:20px}.entry-meta{font-size:9px;letter-spacing:0}.meta-separator{padding:0 3px}.updating-mark{font-size:9px;writing-mode:vertical-rl;letter-spacing:.1em}.contents-end{padding:32px 0 15px;font-size:11px}.site-footer{margin-top:15px;padding:25px 0 30px;gap:20px}.site-footer .brand{font-size:20px}.site-footer>span{font-size:8px}.site-footer>a:last-child{font-size:10px}.reading .layout{padding:26px 6% 45px}.back-link{margin-bottom:30px}.chapterhead h1{font-size:29px;line-height:1.6;margin-bottom:23px}.chapterhead .eyebrow{font-size:10px;margin-bottom:12px}.chapterhead{margin-bottom:32px;padding-bottom:23px}.chapter-meta{gap:10px}.meta{font-size:10px}.tools>span{display:none}.tools button{min-width:37px;height:36px}.prose{--body:18px;line-height:2}.prose p{margin-bottom:1.35em}.prose h2{font-size:1.14em;margin-bottom:1.25em}.prose section+section{margin-top:48px}.reading .site-footer>span{display:none}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}*,*:before,*:after{transition:none!important}}@media print{.masthead,.sidebar,.tools,.skip,.pager,.reading-progress,.site-footer,.back-link{display:none}body{background:white;color:black}.reading .layout{display:block;padding:0;max-width:none}.prose{font-size:11pt;line-height:1.8}.chapterhead h1{font-size:26pt}.chapterhead{margin-bottom:24px}a{color:inherit}@page{size:A4;margin:20mm}}
/* Illustrated chapter: preserve the complete image within the reading column. */
.prose figure img{display:block;max-width:100%;height:auto;max-height:680px;object-fit:contain}.prose .image-link{display:block}.prose figcaption{overflow-wrap:anywhere}.prose figcaption b{color:var(--ink)}.prose figcaption a{text-decoration:underline;text-underline-offset:.2em}.prose figcaption .credit{margin-top:9px}@media(max-width:600px){.prose figure{margin:28px 0}.prose figure img{max-height:70vh}.prose figcaption{font-size:12px;line-height:1.8}}
/* Real NASA/SDO observation, replacing the former decorative solar plate. */
.brand-sun-photo{display:block;flex:none;width:28px;height:28px;object-fit:contain;border-radius:50%;background:#000}.site-footer>.brand{gap:9px}.site-footer .brand-sun-photo{width:24px;height:24px}.solar-photo{margin:0;min-width:0}.solar-photo>img{display:block;width:100%;height:320px;object-fit:contain;background:#000}.solar-photo figcaption{font:10px/1.8 var(--sans);color:var(--muted);padding:12px 0 0}.solar-photo figcaption a{text-decoration:underline;text-underline-offset:3px}.site-footer>span a{text-decoration:underline;text-underline-offset:2px}@media(max-width:880px){.solar-photo>img{height:275px}}@media(max-width:600px){.solar-photo>img{height:275px}.solar-photo figcaption{font-size:10px}.brand-sun-photo{width:26px;height:26px}}

/* Build-time prose count, separate from edition metadata. */
.reading-stats{display:flex;align-items:baseline;flex-wrap:wrap;gap:6px 9px;font:12px/1.8 var(--sans);color:var(--muted);margin:-14px 0 24px}.reading-stats>span{white-space:nowrap}.stats-dot{color:#a2a495}@media(max-width:600px){.reading-stats{font-size:11px;gap:4px 7px;margin:-10px 0 21px}}

/* Hidden entirely unless an approved, version-matched audio file exists. */
.chapter-audio{margin:-15px 0 38px;padding:18px 0;border-bottom:1px solid var(--line)}.audio-heading{display:flex;justify-content:space-between;flex-wrap:wrap;gap:8px;margin-bottom:12px;font:13px/1.7 var(--sans)}.audio-disclosure{color:var(--muted);font-size:11px}.chapter-audio audio{display:block;width:100%;max-width:100%;height:42px}.audio-options{display:flex;align-items:center;flex-wrap:wrap;gap:12px;margin-top:10px;font:11px/1.8 var(--sans);color:var(--muted)}.audio-speed{font:inherit;border:1px solid var(--line);background:var(--paper);color:var(--ink);padding:4px 6px;margin-left:5px}.audio-speed:focus-visible{outline:2px solid var(--accent);outline-offset:3px}.audio-status{overflow-wrap:anywhere}@media print{.chapter-audio{display:none}}