/* Pronab Roy Series Reader — full-screen eBook reader. No external assets. */
:root {
	--prsr-font-size: 19px;
	--prsr-measure: 42rem;
	--prsr-bg: #ffffff;
	--prsr-fg: #1d1f23;
	--prsr-muted: #5f6672;
	--prsr-border: #e3e5e8;
	--prsr-accent: #1f5fbf;
	--prsr-bar: rgba(255, 255, 255, 0.94);
	--prsr-code-bg: #f5f7fa;
	--prsr-code-fg: #1d1f23;
	--prsr-inline-code-bg: rgba(27, 31, 35, 0.07);
	--prsr-shadow: 0 10px 30px rgba(0, 0, 0, 0.18);
	--prsr-tok-k: #8f2bb3; --prsr-tok-s: #0a7a34; --prsr-tok-c: #6a737d; --prsr-tok-n: #b35900;
	--prsr-tok-t: #0f6a8f; --prsr-tok-f: #3a4fc6; --prsr-tok-v: #b31d28; --prsr-tok-o: #6b4bb3; --prsr-tok-pr: #1f5fbf;
	--prsr-serif: Charter, "Bitstream Charter", "Sitka Text", Cambria, Georgia, "Times New Roman", serif;
	--prsr-sans: system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
	--prsr-mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, "Cascadia Mono", "Liberation Mono", "DejaVu Sans Mono", monospace;
	color-scheme: light;
}
[data-theme="sepia"] {
	--prsr-bg: #f4ecd8; --prsr-fg: #3b2f20; --prsr-muted: #76664f; --prsr-border: #dccfb0; --prsr-accent: #8a4b10;
	--prsr-bar: rgba(244, 236, 216, 0.95); --prsr-code-bg: #ebe1c8; --prsr-code-fg: #3b2f20; --prsr-inline-code-bg: rgba(91, 70, 40, 0.1);
	--prsr-tok-k: #8b2a6b; --prsr-tok-s: #4f6b12; --prsr-tok-c: #8a7a60; --prsr-tok-n: #a4480a; --prsr-tok-t: #1e6070; --prsr-tok-f: #3d4d9a; --prsr-tok-v: #a0281c; --prsr-tok-o: #6a4a8a; --prsr-tok-pr: #2d5c8a;
}
[data-theme="dark"] {
	--prsr-bg: #16181d; --prsr-fg: #d9dce1; --prsr-muted: #9aa1ad; --prsr-border: #2c3038; --prsr-accent: #7fb0ff;
	--prsr-bar: rgba(22, 24, 29, 0.95); --prsr-code-bg: #0f1115; --prsr-code-fg: #d9dce1; --prsr-inline-code-bg: rgba(255, 255, 255, 0.08);
	--prsr-shadow: 0 10px 30px rgba(0, 0, 0, 0.6);
	--prsr-tok-k: #d2a8ff; --prsr-tok-s: #a5d6a7; --prsr-tok-c: #8b949e; --prsr-tok-n: #f2b36f; --prsr-tok-t: #79c0ff; --prsr-tok-f: #a3b6ff; --prsr-tok-v: #ff9492; --prsr-tok-o: #c6a8ff; --prsr-tok-pr: #7fb0ff;
	color-scheme: dark;
}

*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; text-size-adjust: 100%; scroll-padding-top: 4.5rem; }
body.prsr-reader {
	margin: 0;
	background: var(--prsr-bg);
	color: var(--prsr-fg);
	font-family: var(--prsr-serif);
	font-size: var(--prsr-font-size);
	line-height: 1.7;
	transition: background-color .2s ease, color .2s ease;
	overflow-wrap: break-word;
}
.screen-reader-text { position: absolute !important; width: 1px; height: 1px; overflow: hidden; clip: rect(1px, 1px, 1px, 1px); white-space: nowrap; }
.prsr-skip { position: absolute; left: -9999px; top: 0; z-index: 100; background: var(--prsr-accent); color: #fff; padding: .5rem 1rem; }
.prsr-skip:focus { left: .5rem; top: .5rem; }
a { color: var(--prsr-accent); }
:focus-visible { outline: 2px solid var(--prsr-accent); outline-offset: 2px; }

/* Progress bar */
.prsr-r-progress { position: fixed; top: 0; left: 0; right: 0; height: 3px; z-index: 60; background: transparent; }
.prsr-r-progress__fill { display: block; height: 100%; width: 0; background: var(--prsr-accent); transition: width .1s linear; }

/* Toolbar */
.prsr-toolbar {
	position: sticky; top: 0; z-index: 50;
	display: flex; align-items: center; gap: .5rem;
	padding: .55rem max(.75rem, env(safe-area-inset-right)) .55rem max(.75rem, env(safe-area-inset-left));
	background: var(--prsr-bar); border-bottom: 1px solid var(--prsr-border);
	font-family: var(--prsr-sans); font-size: 15px; line-height: 1.2;
	-webkit-backdrop-filter: saturate(1.4) blur(8px); backdrop-filter: saturate(1.4) blur(8px);
}
.prsr-toolbar__title { flex: 1 1 auto; min-width: 0; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; font-weight: 600; color: var(--prsr-muted); text-align: center; }
.prsr-toolbar__tools { display: flex; align-items: center; gap: .35rem; flex: 0 0 auto; }
.prsr-themes { display: inline-flex; gap: .3rem; margin-left: .35rem; }
.prsr-btn {
	display: inline-flex; align-items: center; justify-content: center; gap: .35rem;
	min-height: 2.25rem; min-width: 2.25rem; padding: .35rem .7rem;
	font: 600 15px/1 var(--prsr-sans); color: var(--prsr-fg);
	background: transparent; border: 1px solid var(--prsr-border); border-radius: 8px;
	cursor: pointer; text-decoration: none; -webkit-tap-highlight-color: transparent;
}
.prsr-btn:hover { border-color: var(--prsr-accent); color: var(--prsr-accent); }
.prsr-btn:disabled { opacity: .4; cursor: default; border-color: var(--prsr-border); color: var(--prsr-fg); }
.prsr-btn--small { font-size: 13px; }
.prsr-btn--primary { background: var(--prsr-accent); border-color: var(--prsr-accent); color: #fff; }
.prsr-btn--primary:hover { color: #fff; filter: brightness(1.08); }
[data-theme="dark"] .prsr-btn--primary { color: #0d1117; }
.prsr-btn--icon span[aria-hidden="true"], .prsr-btn--exit span[aria-hidden="true"] { font-size: 1.2em; line-height: 1; }
.prsr-theme-btn { width: 1.9rem; height: 1.9rem; border-radius: 50%; border: 2px solid var(--prsr-border); cursor: pointer; padding: 0; }
.prsr-theme-btn--light { background: #ffffff; }
.prsr-theme-btn--sepia { background: #f4ecd8; }
.prsr-theme-btn--dark { background: #16181d; }
.prsr-theme-btn[aria-pressed="true"] { border-color: var(--prsr-accent); box-shadow: 0 0 0 2px var(--prsr-bg), 0 0 0 4px var(--prsr-accent); }

/* Drawer */
.prsr-overlay { position: fixed; inset: 0; z-index: 70; background: rgba(0, 0, 0, .35); }
.prsr-drawer {
	position: fixed; top: 0; bottom: 0; left: 0; z-index: 80;
	width: min(24rem, 88vw); overflow-y: auto; -webkit-overflow-scrolling: touch; overscroll-behavior: contain;
	background: var(--prsr-bg); color: var(--prsr-fg); border-right: 1px solid var(--prsr-border); box-shadow: var(--prsr-shadow);
	font-family: var(--prsr-sans); font-size: 15px; line-height: 1.4;
	padding: 0 0 2rem; animation: prsr-slide .2s ease-out;
}
.prsr-drawer[hidden], .prsr-overlay[hidden], .prsr-resume[hidden] { display: none; }
@keyframes prsr-slide { from { transform: translateX(-100%); } to { transform: none; } }
@media (prefers-reduced-motion: reduce) { .prsr-drawer { animation: none; } .prsr-r-progress__fill, body.prsr-reader { transition: none; } }
.prsr-drawer__head { position: sticky; top: 0; display: flex; align-items: center; justify-content: space-between; padding: .6rem .75rem .6rem 1rem; background: var(--prsr-bg); border-bottom: 1px solid var(--prsr-border); }
body.prsr-drawer-open { overflow: hidden; }

/* TOC (drawer + title page) */
.prsr-r-toc { padding: .25rem .5rem; }
.prsr-r-toc__part { margin: 1rem .5rem .25rem; font: 700 12px/1.3 var(--prsr-sans); text-transform: uppercase; letter-spacing: .06em; color: var(--prsr-muted); }
.prsr-r-toc__list { list-style: none; margin: 0; padding: 0; }
.prsr-r-toc__link { display: flex; gap: .6rem; align-items: baseline; padding: .5rem .5rem; border-radius: 6px; color: var(--prsr-fg); text-decoration: none; }
a.prsr-r-toc__link:hover { background: var(--prsr-inline-code-bg); color: var(--prsr-accent); }
.prsr-r-toc__link[aria-current="true"] { background: var(--prsr-inline-code-bg); color: var(--prsr-accent); font-weight: 600; }
.prsr-r-toc__num { flex: 0 0 1.6rem; text-align: right; color: var(--prsr-muted); font-variant-numeric: tabular-nums; }
.is-soon .prsr-r-toc__link, .prsr-soonpage .is-soon { color: var(--prsr-muted); }
.prsr-r-soon { font-style: normal; font-size: .8em; padding: .05rem .4rem; border-radius: 999px; border: 1px solid var(--prsr-border); white-space: nowrap; color: var(--prsr-muted); }

/* Resume prompt */
.prsr-resume {
	position: fixed; z-index: 65; left: 50%; bottom: calc(4.5rem + env(safe-area-inset-bottom)); transform: translateX(-50%);
	width: min(30rem, calc(100vw - 1.5rem)); padding: 1rem 1.1rem;
	background: var(--prsr-bg); color: var(--prsr-fg); border: 1px solid var(--prsr-border); border-radius: 12px; box-shadow: var(--prsr-shadow);
	font-family: var(--prsr-sans); font-size: 15px; line-height: 1.4;
}
.prsr-resume__title { margin: 0 0 .25rem; font-weight: 700; }
.prsr-resume__text { margin: 0 0 .75rem; color: var(--prsr-muted); }
.prsr-resume__actions { display: flex; flex-wrap: wrap; gap: .5rem; }

/* Pages */
.prsr-main { display: block; max-width: var(--prsr-measure); margin: 0 auto; padding: 2rem 1.25rem 6rem; outline: none; }
.js .prsr-page { display: none; }
.js .prsr-page.is-active { display: block; }
.no-js .prsr-page + .prsr-page { border-top: 1px solid var(--prsr-border); margin-top: 3rem; padding-top: 2rem; }
.no-js .prsr-pager, .no-js #prsr-toc-toggle, .no-js .prsr-toolbar__tools { display: none; }
.prsr-preview-note { font: 14px/1.4 var(--prsr-sans); background: #fff3cd; color: #664d03; border: 1px solid #ffe69c; border-radius: 8px; padding: .6rem .8rem; }

.prsr-titlepage__inner { text-align: center; padding: 3rem 0 2rem; border-bottom: 1px solid var(--prsr-border); margin-bottom: 2rem; }
.prsr-titlepage__title { font-size: 2.1em; line-height: 1.2; margin: 0 0 .5rem; letter-spacing: -.01em; }
.prsr-titlepage__series { margin: 0; color: var(--prsr-muted); font-family: var(--prsr-sans); font-size: .85em; text-transform: uppercase; letter-spacing: .08em; }
.prsr-titlepage__author { margin: 1.25rem 0 1.5rem; font-style: italic; font-size: 1.1em; }
.prsr-titlepage__desc { text-align: left; color: var(--prsr-fg); }
.prsr-start { margin-top: 1rem; font-size: 16px; padding: .7rem 1.2rem; }
.prsr-r-toc--title { padding: 0; }
.prsr-r-toc--title h2 { font-size: 1.3em; }

.prsr-chapter-head { margin: 1rem 0 2rem; }
.prsr-chapter-head__label { margin: 0 0 .4rem; font: 600 13px/1.4 var(--prsr-sans); text-transform: uppercase; letter-spacing: .07em; color: var(--prsr-muted); }
.prsr-chapter-head__title { margin: 0; font-size: 1.9em; line-height: 1.2; letter-spacing: -.01em; }
.prsr-chapter-foot { margin-top: 3rem; padding-top: 1rem; border-top: 1px solid var(--prsr-border); font: 14px/1.5 var(--prsr-sans); }

/* Content typography */
.prsr-content h1, .prsr-content h2, .prsr-content h3, .prsr-content h4 { line-height: 1.25; margin: 2em 0 .6em; }
.prsr-content h1 { font-size: 1.6em; } .prsr-content h2 { font-size: 1.4em; } .prsr-content h3 { font-size: 1.18em; } .prsr-content h4 { font-size: 1.05em; }
.prsr-content p, .prsr-content ul, .prsr-content ol, .prsr-content blockquote, .prsr-content figure { margin: 0 0 1.1em; }
.prsr-content ul, .prsr-content ol { padding-left: 1.4em; }
.prsr-content li + li { margin-top: .3em; }
.prsr-content blockquote { margin-left: 0; padding: .6em 1em; border-left: 4px solid var(--prsr-accent); background: var(--prsr-inline-code-bg); border-radius: 0 8px 8px 0; }
.prsr-content blockquote > :last-child { margin-bottom: 0; }
.prsr-content img, .prsr-content video, .prsr-content iframe { max-width: 100%; height: auto; }
.prsr-content hr { border: 0; border-top: 1px solid var(--prsr-border); margin: 2.5em 0; }
.prsr-content figcaption { font: 14px/1.4 var(--prsr-sans); color: var(--prsr-muted); text-align: center; }

/* Code */
.prsr-content code, .prsr-content kbd, .prsr-content samp { font-family: var(--prsr-mono); font-size: .85em; }
.prsr-content :not(pre) > code { background: var(--prsr-inline-code-bg); padding: .1em .35em; border-radius: 4px; overflow-wrap: anywhere; }
.prsr-content pre {
	margin: 0 0 1.3em; padding: 1em 1.1em; overflow-x: auto; -webkit-overflow-scrolling: touch;
	background: var(--prsr-code-bg); color: var(--prsr-code-fg); border: 1px solid var(--prsr-border); border-radius: 8px;
	font-family: var(--prsr-mono); font-size: .8em; line-height: 1.55; tab-size: 4; -moz-tab-size: 4;
	white-space: pre; word-wrap: normal; overflow-wrap: normal;
}
.prsr-content pre code { font-size: inherit; background: none; padding: 0; border-radius: 0; white-space: inherit; color: inherit; display: block; min-width: max-content; }
.prsr-content div.sourceCode { margin: 0 0 1.3em; overflow: visible; background: none; }
.prsr-content div.sourceCode pre { margin: 0; }
.prsr-content pre code > span { display: inline; }
.prsr-content pre code > span > a:empty { display: none; }

/* Token colours: built-in highlighter (.prsr-tok-*) and Pandoc output (.kw, .dt, ...). */
.prsr-tok-k, code.sourceCode .kw, code.sourceCode .cf { color: var(--prsr-tok-k); }
.prsr-tok-s, code.sourceCode .st, code.sourceCode .ch, code.sourceCode .ss, code.sourceCode .vs, code.sourceCode .sc { color: var(--prsr-tok-s); }
.prsr-tok-c, code.sourceCode .co, code.sourceCode .do, code.sourceCode .cv, code.sourceCode .an, code.sourceCode .in { color: var(--prsr-tok-c); font-style: italic; }
.prsr-tok-n, code.sourceCode .dv, code.sourceCode .bn, code.sourceCode .fl, code.sourceCode .cn { color: var(--prsr-tok-n); }
.prsr-tok-t, code.sourceCode .dt { color: var(--prsr-tok-t); }
.prsr-tok-f, code.sourceCode .fu, code.sourceCode .bu, code.sourceCode .ex { color: var(--prsr-tok-f); }
.prsr-tok-v, code.sourceCode .va, code.sourceCode .al, code.sourceCode .er { color: var(--prsr-tok-v); }
.prsr-tok-o, code.sourceCode .at { color: var(--prsr-tok-o); }
.prsr-tok-pr { color: var(--prsr-tok-pr); }
.prsr-tok-p, .prsr-tok-a, code.sourceCode .pp, code.sourceCode .im { color: var(--prsr-tok-t); }

/* Tables */
.prsr-table-wrap { overflow-x: auto; -webkit-overflow-scrolling: touch; margin: 0 0 1.3em; border: 1px solid var(--prsr-border); border-radius: 8px; }
.prsr-content table { border-collapse: collapse; width: 100%; font-family: var(--prsr-sans); font-size: .82em; line-height: 1.45; }
.prsr-content th, .prsr-content td { padding: .55em .75em; border-bottom: 1px solid var(--prsr-border); text-align: left; vertical-align: top; }
.prsr-content th { background: var(--prsr-inline-code-bg); font-weight: 600; white-space: nowrap; }
.prsr-content tr:last-child td { border-bottom: 0; }
.prsr-table-wrap table { margin: 0; min-width: 32rem; }

/* Pager */
.prsr-pager {
	position: fixed; left: 0; right: 0; bottom: 0; z-index: 50;
	display: flex; align-items: center; justify-content: space-between; gap: .5rem;
	padding: .5rem max(.75rem, env(safe-area-inset-right)) calc(.5rem + env(safe-area-inset-bottom)) max(.75rem, env(safe-area-inset-left));
	background: var(--prsr-bar); border-top: 1px solid var(--prsr-border);
	font-family: var(--prsr-sans);
	-webkit-backdrop-filter: saturate(1.4) blur(8px); backdrop-filter: saturate(1.4) blur(8px);
}
.prsr-pager__status { font-size: 14px; color: var(--prsr-muted); text-align: center; flex: 1 1 auto; font-variant-numeric: tabular-nums; }

/* Small screens */
@media (max-width: 640px) {
	.prsr-btn__label { display: none; }
	.prsr-toolbar { gap: .3rem; padding-left: .5rem; padding-right: .5rem; }
	.prsr-toolbar__title { display: none; }
	.prsr-toolbar__tools { flex: 1 1 auto; justify-content: center; }
	.prsr-themes { margin-left: .15rem; gap: .2rem; }
	.prsr-theme-btn { width: 1.7rem; height: 1.7rem; }
	.prsr-main { padding: 1.25rem 1rem 6rem; }
	.prsr-titlepage__inner { padding-top: 1.5rem; }
	.prsr-content pre { margin-left: -1rem; margin-right: -1rem; border-radius: 0; border-left: 0; border-right: 0; }
	.prsr-content div.sourceCode pre { margin-left: -1rem; margin-right: -1rem; }
}

@media print {
	.prsr-toolbar, .prsr-pager, .prsr-drawer, .prsr-overlay, .prsr-resume, .prsr-r-progress { display: none !important; }
}