/* Prashnika brand: "Shirorekha Readout" (docs/plans/brand/, owner's pick 2026-10-17). Loaded AFTER site.css and overrides it:
   cream paper and serif, the Devanagari headline bar as the page's one heavy rule, square corners, rules instead of glass, a dark
   readout panel with a lamp where the server has checked something, turmeric as the only accent. The two themes keep their names
   (`silver` shows as the light paper, `glass` as the dark slate) so the saved choice and the scripts keep working. @map:brand */

/* @fonts-begin: written by docs/plans/brand/get_fonts.py; the licences are in static/fonts/LICENSES.md */
@font-face { font-family: "JetBrains Mono"; font-style: normal; font-weight: 400 500; font-display: swap; src: url("/static/fonts/jetbrains-mono-normal-latin.woff2?v=612aec61ba") format("woff2"); unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD; }
@font-face { font-family: "JetBrains Mono"; font-style: normal; font-weight: 400 500; font-display: swap; src: url("/static/fonts/jetbrains-mono-normal-latin-ext.woff2?v=ea07cc5a05") format("woff2"); unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C4, U+2113, U+2C60-2C7F, U+A720-A7FF; }
@font-face { font-family: "Newsreader"; font-style: italic; font-weight: 400 500; font-display: swap; src: url("/static/fonts/newsreader-italic-latin.woff2?v=c3f1cb5416") format("woff2"); unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD; }
@font-face { font-family: "Newsreader"; font-style: italic; font-weight: 400 500; font-display: swap; src: url("/static/fonts/newsreader-italic-latin-ext.woff2?v=30d55c3a49") format("woff2"); unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C4, U+2113, U+2C60-2C7F, U+A720-A7FF; }
@font-face { font-family: "Newsreader"; font-style: normal; font-weight: 400 700; font-display: swap; src: url("/static/fonts/newsreader-normal-latin.woff2?v=601e69e732") format("woff2"); unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD; }
@font-face { font-family: "Newsreader"; font-style: normal; font-weight: 400 700; font-display: swap; src: url("/static/fonts/newsreader-normal-latin-ext.woff2?v=0f0fa00669") format("woff2"); unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C4, U+2113, U+2C60-2C7F, U+A720-A7FF; }
@font-face { font-family: "Yatra One"; font-style: normal; font-weight: 400; font-display: swap; src: url("/static/fonts/yatra-one-normal-devanagari.woff2?v=e795e6542d") format("woff2"); unicode-range: U+0900-097F, U+1CD0-1CF4, U+1CF7-1CF9, U+200C-200D, U+20A8, U+20B9, U+20F0, U+25CC, U+A830-A839, U+A8E0-A8FF, U+11B00-11B0A; }
@font-face { font-family: "Yatra One"; font-style: normal; font-weight: 400; font-display: swap; src: url("/static/fonts/yatra-one-normal-latin.woff2?v=86e1ebd676") format("woff2"); unicode-range: U+0000-00FF, U+0131, U+0152-0153, U+02BB-02BC, U+02C6, U+02DA, U+02DC, U+0304, U+0308, U+0329, U+2000-206F, U+20AC, U+2122, U+2191, U+2193, U+2212, U+2215, U+FEFF, U+FFFD; }
@font-face { font-family: "Yatra One"; font-style: normal; font-weight: 400; font-display: swap; src: url("/static/fonts/yatra-one-normal-latin-ext.woff2?v=0ebd96e548") format("woff2"); unicode-range: U+0100-02BA, U+02BD-02C5, U+02C7-02CC, U+02CE-02D7, U+02DD-02FF, U+0304, U+0308, U+0329, U+1D00-1DBF, U+1E00-1E9F, U+1EF2-1EFF, U+2020, U+20A0-20AB, U+20AD-20C4, U+2113, U+2C60-2C7F, U+A720-A7FF; }
/* @fonts-end */

/* ------------------------------------------------------------ tokens: one set of values per theme; most glass effects are tokens, so they go flat here */
:root {
  --f-text: "Newsreader", Georgia, "Times New Roman", serif;
  --f-dev: "Yatra One", "Nirmala UI", "Noto Sans Devanagari", sans-serif;
  --f-mono: "JetBrains Mono", ui-monospace, Consolas, monospace;
  --lamp: #4ADE80; --turmeric: #F2B90D;
  --rule-y: 43px; --rule-h: 7px; --mark-fs: 56px;     /* where the wordmark's own bar sits at 56px in the left menu: the rule is drawn at the same height */
}
:root[data-theme="silver"] {
  color-scheme: light;
  --qb-bg-base: #F3EDE0; --qb-bg-glow: none; --qb-surface: transparent; --qb-surface-strong: #EBE4D3; --qb-bar-bg: #EFE8D8; --qb-blur: none;
  --qb-text-heading: #1C1B18; --qb-text-primary: #1C1B18; --qb-text-secondary: #3A372F; --qb-text-muted: #5C574B;
  --qb-border: #CFC5AB; --qb-border-strong: #8F8567; --qb-accent: #F2B90D; --qb-accent-tint: rgba(242, 185, 13, 0.28); --qb-accent-fg: #1C1B18;
  --qb-link: #1C1B18; --qb-primary-fg: #1C1B18; --qb-backdrop: rgba(28, 27, 24, 0.35); --qb-mark-bg: rgba(242, 185, 13, 0.5); --qb-mark-fg: #1C1B18;
  --qb-notice-bg: #F6E7B8; --qb-notice-border: #B79B3A; --qb-ai-bg: transparent; --qb-ai-border: #8F8567;
  --qb-correct-bg: rgba(46, 107, 62, 0.12); --qb-correct-border: #2E6B3E; --qb-correct-fg: #2E6B3E; --qb-code-bg: #EAE2CF;
  --qb-shadow: none; --qb-glass-fill: transparent; --qb-glass-shadow: none; --qb-glass-shadow-sm: none; --qb-sheet-fill: #F3EDE0; --qb-menu-fill: #EFE8D8;
  --qb-badge-bg: transparent; --qb-rail: rgba(28, 27, 24, 0.06); --qb-hero-bg: transparent;
  --sub-cs: #4B5BC4; --sub-ph: #B8610F; --sub-ch: #B5456B; --sub-ma: #2F8044; --sub-el: #0F7C7C; --sub-lt: #8A3FA0; --sub-pe: #7D6310;
  /* the answer panel and a tool's readout follow the theme: light cream with an ink rule here, the dark panel in `glass` (a light page with a dark panel was reported as a bug, 2026-10-18) @map:readout */
  --panel: #EBE4D3; --panel-ink: #1C1B18; --panel-2: #3A372F; --panel-muted: #5C574B; --panel-line: #CFC5AB; --panel-edge: #8F8567; --panel-code: #E0D7C0;
  --panel-ok: #2E6B3E; --panel-ok-bg: rgba(46, 107, 62, 0.12); --panel-accent: #7A5C00; --panel-lamp: #2E6B3E; --panel-glow: none;
}
:root[data-theme="glass"] {
  color-scheme: dark;
  --qb-bg-base: #1A1814; --qb-bg-glow: none; --qb-surface: transparent; --qb-surface-strong: #23201A; --qb-bar-bg: #151310; --qb-blur: none;
  --qb-text-heading: #F0EADC; --qb-text-primary: #F0EADC; --qb-text-secondary: #D8D0BC; --qb-text-muted: #BDB49D;
  --qb-border: #3C372D; --qb-border-strong: #5A5345; --qb-accent: #F2B90D; --qb-accent-tint: rgba(242, 185, 13, 0.22); --qb-accent-fg: #F2B90D;
  --qb-link: #F0EADC; --qb-primary-fg: #1A1814; --qb-backdrop: rgba(10, 9, 7, 0.55); --qb-mark-bg: rgba(242, 185, 13, 0.45); --qb-mark-fg: #FFFFFF;
  --qb-notice-bg: #3A3018; --qb-notice-border: #8A6D1A; --qb-ai-bg: transparent; --qb-ai-border: #5A5345;
  --qb-correct-bg: rgba(134, 204, 149, 0.14); --qb-correct-border: #86CC95; --qb-correct-fg: #86CC95; --qb-code-bg: #12100D;
  --qb-shadow: none; --qb-glass-fill: transparent; --qb-glass-shadow: none; --qb-glass-shadow-sm: none; --qb-sheet-fill: #1F1C17; --qb-menu-fill: #23201A;
  --qb-badge-bg: transparent; --qb-rail: rgba(240, 234, 220, 0.07); --qb-hero-bg: transparent;
  --sub-cs: #8E9BFF; --sub-ph: #F0A04B; --sub-ch: #F08AAE; --sub-ma: #7FD08F; --sub-el: #4FC3C3; --sub-lt: #D08CE6; --sub-pe: #D8BE5B;
  --panel: #15130F; --panel-ink: #F0EADC; --panel-2: #CFC8B6; --panel-muted: #ABA498; --panel-line: #37332B; --panel-edge: #4D473C; --panel-code: #080706;
  --panel-ok: #86D096; --panel-ok-bg: rgba(134, 208, 150, 0.16); --panel-accent: #F2B90D; --panel-lamp: #4ADE80; --panel-glow: 0 0 6px #4ADE80;
}
/* site.css re-tints the home, tools and guides pages (body.soft) with their own softer values: here every page uses the same set */
:root[data-theme="silver"] body.soft, :root[data-theme="silver"].is-home body {
  --qb-text-heading: #1C1B18; --qb-text-primary: #1C1B18; --qb-text-secondary: #3A372F; --qb-text-muted: #5C574B; --qb-border: #CFC5AB; --qb-border-strong: #8F8567;
  --qb-accent-fg: #1C1B18; --qb-link: #1C1B18; --qb-glass-shadow: none; }
:root[data-theme="glass"] body.soft, :root[data-theme="glass"].is-home body {
  --qb-text-heading: #F0EADC; --qb-text-primary: #F0EADC; --qb-text-secondary: #D8D0BC; --qb-text-muted: #BDB49D; --qb-border: #3C372D; --qb-border-strong: #5A5345;
  --qb-accent-fg: #F2B90D; --qb-link: #F0EADC; --qb-glass-shadow: none; }
:root[data-theme] .sub-computer-science { --sub: var(--sub-cs); } :root[data-theme] .sub-physics { --sub: var(--sub-ph); }
:root[data-theme] .sub-chemistry { --sub: var(--sub-ch); } :root[data-theme] .sub-mathematics { --sub: var(--sub-ma); }
:root[data-theme] .sub-english-language { --sub: var(--sub-el); } :root[data-theme] .sub-english-literature { --sub: var(--sub-lt); }
:root[data-theme] .sub-physical-education { --sub: var(--sub-pe); }

/* ------------------------------------------------------------ the one rule: nothing is rounded, raised or blurred, except a lamp or a dot */
:root[data-theme] *, :root[data-theme] *::before, :root[data-theme] *::after { border-radius: 0 !important; box-shadow: none !important; text-shadow: none !important; }
:root[data-theme] .sdot, :root[data-theme] .dot, :root[data-theme] .lamp, :root[data-theme] .lamp i, :root[data-theme] .led, :root[data-theme] input[type="radio"], :root[data-theme] .tdot { border-radius: 50% !important; }
:root[data-theme] body::before { background: none; }
:root[data-theme] .blurred, :root[data-theme] .bar, :root[data-theme] .dialog-box { backdrop-filter: none !important; -webkit-backdrop-filter: none !important; }
:root[data-theme] body { font: 17px/1.6 var(--f-text); font-feature-settings: "lnum"; background-color: var(--qb-bg-base); }
:root[data-theme] button, :root[data-theme] input, :root[data-theme] select, :root[data-theme] textarea { font-family: var(--f-text); }
:root[data-theme] h1, :root[data-theme] h2, :root[data-theme] h3 { font-family: var(--f-text); letter-spacing: -0.015em; }
:root[data-theme] h1 { font-weight: 700; letter-spacing: -0.025em; }
:root[data-theme] a { text-decoration-thickness: 2px; text-decoration-skip-ink: none; text-underline-offset: 3px; }
:root[data-theme] p, :root[data-theme] li { text-wrap: pretty; }

/* ------------------------------------------------------------ the heavy rule across the top, and the logo hung from it */
:root[data-theme] body::after { content: ""; position: absolute; left: 0; right: 0; top: var(--rule-y); height: var(--rule-h); background: var(--qb-text-heading); z-index: 15; pointer-events: none; }
@media (min-width: 900px) { :root[data-theme] .top { padding-top: 66px; } :root[data-theme].is-list main { padding-top: 66px; } }   /* below the rule, never through the search row */
:root[data-theme] .sph, :root[data-theme] .hm-hero::before, :root[data-theme] .hm-hero::after, :root[data-theme] .hero::before, :root[data-theme] .hero::after, :root[data-theme] .pg-hero::before, :root[data-theme] .pg-hero::after { display: none !important; }
/* the highlighter on the hero's key words: a turmeric bar under them in light, ink on turmeric in dark; never a blue word */
:root[data-theme] .hm-hero h1 em, :root[data-theme] .hero h1 em, :root[data-theme] h1 em { font-style: normal; color: inherit; background: linear-gradient(transparent 64%, var(--qb-accent) 64%, var(--qb-accent) 94%, transparent 94%); padding: 0 2px; }
:root[data-theme="glass"] .hm-hero h1 em, :root[data-theme="glass"] .hero h1 em, :root[data-theme="glass"] h1 em { background: var(--qb-accent); color: #1A1814; padding: 0 6px; }
:root[data-theme] .bar { background: var(--qb-bar-bg); border-bottom: 0; border-right: 1px solid var(--qb-border-strong); }
:root[data-theme] .brand .bubble { display: none !important; }
:root[data-theme] .brand .word { display: flex !important; flex-direction: column; align-items: flex-start; gap: 0; line-height: 1; }
:root[data-theme] .brand .word span { order: -1; font: 400 var(--mark-fs)/1.25 var(--f-dev); letter-spacing: 0; color: var(--qb-text-heading); }
:root[data-theme] .brand .word b { order: 0; font: 700 11px/1 var(--f-text); letter-spacing: 0.34em; margin: 2px 0 0; text-transform: uppercase; color: var(--qb-text-heading); }
:root[data-theme] .topnav, :root[data-theme] .topnav a { border-radius: 0; }
:root[data-theme] .topnav { background: none; border: 0; padding: 0; }
:root[data-theme] .topnav a { font: 600 15px/1.2 var(--f-text); font-variant: small-caps; letter-spacing: 0.06em; height: auto; min-height: 36px; border-bottom: 3px solid transparent; }
:root[data-theme] .topnav a:hover { background: none; color: var(--qb-text-heading); border-bottom-color: var(--qb-border-strong); }
:root[data-theme] .topnav a.on { background: none; color: var(--qb-text-heading); border-bottom-color: var(--qb-accent); font-weight: 700; }
:root[data-theme] .nl, :root[data-theme] .ntag { font-family: var(--f-text); font-variant: small-caps; letter-spacing: 0.1em; }
:root[data-theme] .icon { background: none; border: 1px solid var(--qb-border-strong); }

/* ------------------------------------------------------------ buttons, chips, fields: ink, rules, small caps */
:root[data-theme] .btn { background: transparent; border: 1px solid var(--qb-text-heading); color: var(--qb-text-heading); font: 600 15px/1 var(--f-text); height: 44px; }
:root[data-theme] .btn:hover { background: var(--qb-rail); }
:root[data-theme] .btn.primary, :root[data-theme="silver"] .btn.primary { background: var(--qb-text-heading); color: var(--qb-bg-base); border-color: var(--qb-text-heading); font-weight: 700; }
:root[data-theme] .btn.primary:hover { background: var(--qb-text-secondary); }
:root[data-theme] .pill, :root[data-theme] .chip, :root[data-theme] .fchip, :root[data-theme] .tagchip, :root[data-theme] .sortbtn { background: none; border: 0; border-bottom: 3px solid transparent;
  padding: 0 2px; min-height: 32px; font: 500 15px/1.3 var(--f-text); font-variant: small-caps; letter-spacing: 0.05em; color: var(--qb-text-secondary); }
:root[data-theme] .pill.on, :root[data-theme] .chip.on, :root[data-theme] .fchip.on { background: none; border-bottom-color: var(--qb-accent); color: var(--qb-text-heading); font-weight: 700; }
:root[data-theme] .tagchip { min-height: 0; color: var(--qb-text-muted); border-bottom: 0; }
/* version buttons of a note (@map:note-versions): square, ruled, the open one filled with ink */
:root[data-theme] .versions .vtab { border-radius: 0; border: 1px solid var(--qb-text-heading); background: transparent; color: var(--qb-text-heading); font: 600 15px/1 var(--f-text); }
:root[data-theme] .versions .vtab:hover { background: var(--qb-rail); }
:root[data-theme] .versions .vtab[aria-current="page"] { background: var(--qb-text-heading); color: var(--qb-bg-base); border-color: var(--qb-text-heading); }
:root[data-theme] .versions .vhead { font-variant: small-caps; text-transform: none; letter-spacing: 0.05em; font-size: 14px; }
:root[data-theme] .search, :root[data-theme] .fsearch, :root[data-theme] .hero-search input, :root[data-theme] .tool-search input, :root[data-theme] .bs-input, :root[data-theme] .field input, :root[data-theme] .field select, :root[data-theme] .field textarea {
  background: transparent !important; border: 0; border-bottom: 2px solid var(--qb-text-heading); }
:root[data-theme] .search { border: 0; border-bottom: 2px solid var(--qb-text-heading); }
:root[data-theme] .sortmenu, :root[data-theme] .dialog-box { background: var(--qb-menu-fill); border: 1px solid var(--qb-border-strong); }
:root[data-theme] .count { background: var(--qb-text-heading); color: var(--qb-bg-base); }
:root[data-theme] ::selection { background: var(--qb-accent); color: #1C1B18; }

/* ------------------------------------------------------------ boxes become rules: hairline outlines, a heavy rule at the top of a section */
:root[data-theme] .glass, :root[data-theme] .card, :root[data-theme] .hero, :root[data-theme] .hm-hero, :root[data-theme] .pg-hero, :root[data-theme] .sidecard, :root[data-theme] .q-card,
:root[data-theme] .ans-card, :root[data-theme] .bs-card, :root[data-theme] .feature, :root[data-theme] .sub-card, :root[data-theme] .kpi, :root[data-theme] .chcard, :root[data-theme] .home-subject, :root[data-theme] .qcard {
  background: transparent; border: 0; border-top: 2px solid var(--qb-text-heading); }
:root[data-theme] .card { border-top-width: 1px; border-top-color: var(--qb-border-strong); border-bottom: 0; }
:root[data-theme] .hm-hero, :root[data-theme] .pg-hero { border-top: 0; }
:root[data-theme] .kpi b, :root[data-theme] .kpi .big, :root[data-theme] .hm-stats .big { font-family: var(--f-text); font-weight: 700; letter-spacing: -0.03em; }
/* the home figures as a ledger: big numerals under a rule */
:root[data-theme] .hm-stats li { background: none; border: 0; border-top: 2px solid var(--qb-text-heading); padding: 10px 0 4px; }
:root[data-theme] .hm-stats li b { font: 700 clamp(34px, 4.4vw, 50px)/1 var(--f-text); letter-spacing: -0.03em; display: block; }
:root[data-theme] .hm-stats li span { font-variant: small-caps; letter-spacing: 0.1em; color: var(--qb-text-muted); }
:root[data-theme] .ic { background: none; border: 0; color: var(--sub, var(--qb-text-heading)); }
:root[data-theme] .eyebrow, :root[data-theme] .hm-eyebrow { font-family: var(--f-text); font-variant: small-caps; letter-spacing: 0.12em; color: var(--qb-text-muted); background: none; border: 0; padding: 0; }
:root[data-theme] .crumbs a, :root[data-theme] .backlink { border: 0; background: none; padding: 0; color: var(--qb-text-secondary); text-decoration: underline; }

/* ------------------------------------------------------------ the question and its answer: a readout panel with a lamp */
:root[data-theme] .q-card h1 { font-size: clamp(26px, 3.4vw, 36px); line-height: 1.2; font-weight: 600; letter-spacing: -0.015em; }
:root[data-theme] .q-card .lead { font-style: italic; color: var(--qb-text-muted); }
:root[data-theme] .ans-card { border-top: 0; padding: 0; margin: 18px 0; background: none; }
:root[data-theme] .ans-card > h2 { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); }
:root[data-theme] .answer { background: var(--panel); color: var(--panel-ink); border: 0; padding: 0; margin: 0 0 12px; --qb-text-primary: var(--panel-ink); --qb-text-heading: var(--panel-ink);
  --qb-text-secondary: var(--panel-2); --qb-text-muted: var(--panel-muted); --qb-border: var(--panel-line); --qb-link: var(--panel-ink); --qb-code-bg: var(--panel-code); --qb-correct-fg: var(--panel-ok); --qb-correct-bg: var(--panel-ok-bg); }
:root[data-theme] .answer { outline: 1px solid var(--panel-edge); outline-offset: -1px; }
:root[data-theme="silver"] .answer { border-top: 2px solid var(--qb-text-heading); }
:root[data-theme] .answer .answer-head { display: flex; justify-content: space-between; align-items: center; gap: 12px; padding: 9px 14px; border-bottom: 1px solid var(--panel-line); margin: 0; }
:root[data-theme] .answer .answer-head .ah { font: 500 11px/1 var(--f-mono); letter-spacing: 0.14em; text-transform: uppercase; color: var(--panel-accent); margin: 0; }
/* the lamp says only what the site knows: green for the official answer key. AI answers carry no lamp (removed 2026-10-18; the About page says some answers may be written by AI) */
:root[data-theme] .answer .who { font-size: 0; color: var(--panel-ink); background: none; border: 0; padding: 0; display: inline-flex; align-items: center; gap: 7px; }
:root[data-theme] .answer .who::before { content: ""; width: 8px; height: 8px; border-radius: 50% !important; background: var(--panel-lamp); box-shadow: var(--panel-glow) !important; }
:root[data-theme] .answer .who::after { content: "Official key"; font: 500 11px/1 var(--f-mono); letter-spacing: 0.12em; text-transform: uppercase; }
:root[data-theme] .answer > :not(.answer-head) { margin-left: 14px; margin-right: 14px; } :root[data-theme] .answer > p:first-of-type { margin-top: 12px; } :root[data-theme] .answer > :last-child { margin-bottom: 14px; }
:root[data-theme] .answer .body { line-height: 1.55; }
:root[data-theme] .answer svg:not(.dg) { background: #fff; }
/* KaTeX draws square roots, tall matrix and determinant brackets, braces and reaction arrows as <svg> in the ink colour; on the white card above the ink vanished (2026-10-17 hunt, B1.5) @map:brand-diagrams */
:root[data-theme] .answer .katex svg, :root[data-theme] .answer .katex svg path { background: none; }
/* server-drawn diagrams (class dg, palette in qh/palette.py): drawn in the brand's ink on a transparent ground so they take the page; the dark theme and the dark
   readout panel flip the lightness and keep the hues (ink -> light, paper -> the page's dark, magenta stays magenta) @map:brand-diagrams */
:root[data-theme="glass"] svg.dg { filter: invert(1) hue-rotate(180deg); }
/* the paper-coloured parts (label masks, halos, K-map cells) must come out of that flip as exactly the dark they sit on - the filter alone gives a yellowish #171104 -
   so they are drawn in the colour the filter turns into the page's dark (#1A1814) or the answer panel's (#15130F); worked out in docs/brand.md */
:root[data-theme="glass"] svg.dg [fill="#F3EDE0"], :root[data-theme="glass"] svg.dg [style*="fill:#F3EDE0"] { fill: #E9E7E3 !important; }
:root[data-theme="glass"] svg.dg [stroke="#F3EDE0"], :root[data-theme="glass"] svg.dg [style*="stroke:#F3EDE0"] { stroke: #E9E7E3 !important; }
:root[data-theme="glass"] .answer svg.dg [fill="#F3EDE0"], :root[data-theme="glass"] .answer svg.dg [style*="fill:#F3EDE0"] { fill: #EEECE8 !important; }
:root[data-theme="glass"] .answer svg.dg [stroke="#F3EDE0"], :root[data-theme="glass"] .answer svg.dg [style*="stroke:#F3EDE0"] { stroke: #EEECE8 !important; }
:root[data-theme] .opt.correct, :root[data-theme] [data-correct] .correct { background: var(--qb-correct-bg); border-color: var(--qb-correct-border); }

/* ------------------------------------------------------------ keyboard focus: ink on the cream page, turmeric on the dark one (turmeric on cream is 1.5 : 1, WCAG asks 3 : 1) @map:focus-ring */
:root[data-theme] { --focus: var(--qb-text-heading); }
:root[data-theme="glass"] { --focus: var(--turmeric); }
:root[data-theme] :focus-visible { outline: 2px solid var(--focus); outline-offset: 2px; }
:root[data-theme] .field input:focus, :root[data-theme] .field textarea:focus, :root[data-theme] .field select:focus, :root[data-theme] .trybox textarea:focus,
:root[data-theme] .bs-input:focus, :root[data-theme] .hero-search input:focus, :root[data-theme] .mx-cell:focus, :root[data-theme] .dd-btn:focus-visible,
:root[data-theme] .gen-sub .gen-opt:has(input:focus-visible), :root[data-theme] .gen-grid .gen-opt:has(input:focus-visible),
:root[data-theme] .tool-mode input:focus-visible + span { outline: 2px solid var(--focus); outline-offset: 2px; }
:root[data-theme] .search:focus-within, :root[data-theme] .tsearch:focus-within, :root[data-theme] .fsearch:focus-within { border-color: var(--focus); }
:root[data-theme] .filterbox input:focus { border-color: var(--focus); }

/* ------------------------------------------------------------ the tools as framed boxes with a header strip (template 3's boxes) @map:tool-boxes */
:root[data-theme] .tgrid { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 14px; list-style: none; padding: 0; margin: 0; }
:root[data-theme] .tcard { display: block; padding: 0; background: transparent; border: 1px solid var(--qb-text-heading); text-decoration: none; color: var(--qb-text-primary); height: 100%; }
:root[data-theme] .tcard .tc-head { display: flex; justify-content: space-between; gap: 10px; padding: 6px 12px; border-bottom: 1px solid var(--qb-text-heading);
  font: 500 11.5px/1.4 var(--f-mono); letter-spacing: 0.1em; text-transform: uppercase; color: var(--qb-text-heading); }
:root[data-theme] .tcard .tc-head .tc-state { display: inline-flex; align-items: center; gap: 6px; }
:root[data-theme] .tcard .tc-head .tc-state i { width: 7px; height: 7px; border-radius: 50% !important; background: var(--lamp); box-shadow: 0 0 5px var(--lamp) !important; }
:root[data-theme] .tcard > .ic { display: none; }
:root[data-theme] .tcard > span:not(.tc-head):not(.ic) { display: block; padding: 12px 14px 14px; }
:root[data-theme] .tcard b { display: block; font: 700 21px/1.15 var(--f-text); letter-spacing: -0.01em; color: var(--qb-text-heading); margin-bottom: 6px; }
:root[data-theme] .tcard .d { display: block; color: var(--qb-text-secondary); font-size: 16px; line-height: 1.45; }
:root[data-theme] .tcard .you { display: block; margin-top: 8px; font: 400 12.5px/1.45 var(--f-mono); color: var(--qb-text-muted); } :root[data-theme] .tcard .you i { font-style: normal; text-transform: uppercase; letter-spacing: 0.08em; }
:root[data-theme] .tcard:hover { background: var(--qb-rail); } :root[data-theme] .tcard:hover .tc-head { background: var(--qb-accent); color: #1C1B18; border-color: var(--qb-accent); }
:root[data-theme] .tgrp-head { border-top: 2px solid var(--qb-text-heading); padding-top: 10px; } :root[data-theme] .tgrp-head h2 { font-size: 26px; }

/* ------------------------------------------------------------ small things */
:root[data-theme] .foot { border-top: 5px solid var(--qb-text-heading); background: none; }
:root[data-theme] table { font-variant-numeric: lining-nums tabular-nums; }
:root[data-theme] th { font: 600 14px/1.3 var(--f-text); font-variant: small-caps; letter-spacing: 0.08em; text-transform: none; }
:root[data-theme] code, :root[data-theme] pre, :root[data-theme] kbd { font-family: var(--f-mono); }
@media (max-width: 899px) { :root { --mark-fs: 30px; --rule-y: 20px; --rule-h: 4px; }
  :root[data-theme] .brand .word span { display: block; }                    /* site.css hides it on phones: the Devanagari mark is the logo here too */
  :root[data-theme] .brand .word b { font-size: 9px; letter-spacing: 0.3em; margin: 0; }
  :root[data-theme] .bar { height: 58px; padding-top: 0; padding-bottom: 0; flex-wrap: nowrap; border-right: 0; border-bottom: 1px solid var(--qb-border); }   /* the left menu's right edge line is gone; a hairline closes the sticky bar */
  :root[data-theme] .bar .icon { align-self: center; margin-bottom: 0; }
  /* the heavy rule is the wordmark's own headline bar here, not a line across the page: a full-width rule ran on past the wordmark and through the theme button's edge (owner, 2026-10-18),
     and it scrolled away while the sticky bar stayed. The bar is drawn on the Devanagari line, at the height body::after used (--rule-y 20px beside the 30px mark). @map:phone-rule */
  :root[data-theme] body::after { display: none; }
  :root[data-theme] .brand .word span { position: relative; }
  :root[data-theme] .brand .word span::after { content: ""; position: absolute; left: 0; right: 0; top: 10px; height: var(--rule-h); background: var(--qb-text-heading); }
  :root[data-theme] .hm-hero .hero-search input { flex: none; height: 48px; background: transparent !important; border: 0; border-bottom: 2px solid var(--qb-text-heading); padding: 0 2px; } }

/* ------------------------------------------------------------ the top bar (the 4th artifact): no side menu. One row: the wordmark, the links, the theme switch; the
   search sits in a thin strip above the heavy rule. Everything below is one centred column, 1100px wide. @map:topbar */
@media (min-width: 900px) {
  :root { --rule-y: 35px; --rule-h: 7px; --mark-fs: 56px; }
  body { padding-left: 0; }
  :root[data-theme] body::after { left: 0; right: 0; width: min(1100px, calc(100% - 48px)); margin: 0 auto; }   /* the heavy rule runs from the wordmark's left edge to the column's right edge, not past them to the window's edges */
  :root[data-theme] .bar { position: relative; left: auto; top: auto; bottom: auto; z-index: 16; width: min(1100px, calc(100% - 48px)); max-width: none; height: auto; margin: 0 auto; padding: 18px 0 0;
    flex-direction: row; flex-wrap: wrap; align-items: flex-start; gap: 0 18px; background: none; border: 0; overflow: visible; }
  :root[data-theme] .topnav .ni, :root[data-theme] .topnav .ntag, :root[data-theme] .topnav .nl .wide { display: none; }
  :root[data-theme] .brand { padding: 0; flex: none; }
  :root[data-theme] .topnav { order: 1; flex: 1 1 auto; flex-direction: row; flex-wrap: wrap; justify-content: flex-end; align-items: center; gap: 0; width: auto; margin: 0; padding: 40px 0 0; }
  :root[data-theme] .topnav a { flex: none; justify-content: center; gap: 0; height: auto; min-height: 0; padding: 4px 10px 5px; font-size: 15.5px; }
  :root[data-theme] .rail-actions { order: 2; margin: 0; padding: 38px 0 0; position: relative; flex-direction: row; align-items: center; gap: 0; }
  :root[data-theme] .tseg { display: flex; padding: 0; background: none; border: 1px solid var(--qb-border-strong); }
  :root[data-theme] .tseg button { height: 28px; padding: 0 11px; border: 0; background: none; font: 500 13px/1 var(--f-text); font-variant: small-caps; letter-spacing: 0.08em; color: var(--qb-text-secondary); }
  :root[data-theme="glass"] .tseg [data-set-theme="glass"], :root[data-theme="silver"] .tseg [data-set-theme="silver"] { background: var(--qb-text-heading); color: var(--qb-bg-base); font-weight: 700; }
  :root[data-theme] .rail-actions #theme { display: none; }
  /* search and About: a thin strip above the rule, at the right */
  :root[data-theme] .top { position: absolute; top: 4px; left: 0; right: 0; width: min(1100px, calc(100% - 48px)); max-width: none; margin: 0 auto; padding: 0; height: 28px; justify-content: flex-end; gap: 22px; z-index: 17; }
  :root[data-theme] .tsearch { flex: 0 1 320px; height: 28px; padding: 0 2px; gap: 8px; background: none; border: 0; border-bottom: 1px solid var(--qb-border-strong); }
  :root[data-theme] .tsearch input { font-size: 14px; }
  :root[data-theme] .tsearch kbd { display: none; }
  :root[data-theme] .top .btn.sm { margin-left: 0; height: auto; padding: 0; border: 0; background: none; font: 500 14px/1 var(--f-text); font-variant: small-caps; letter-spacing: 0.08em; text-decoration: underline; text-underline-offset: 3px; }
  /* one column under the bar */
  :root[data-theme] main, :root[data-theme] main.page, :root[data-theme].is-list main { width: min(1100px, calc(100% - 48px)); max-width: none; margin: 0 auto; padding: 0; }
  :root[data-theme]:not(.is-home) main::before { content: ""; display: block; margin: 30px 0 22px; border-top: 5px solid var(--qb-text-heading); }
  :root[data-theme] .foot { width: min(1100px, calc(100% - 48px)); max-width: none; margin: 56px auto 0; padding: 18px 0 36px; border-top: 1px solid var(--qb-border-strong); }
  :root[data-theme].is-list .top { display: none; }
}
@media (min-width: 900px) and (max-width: 1119px) {
  :root[data-theme] .bar { flex-wrap: nowrap; gap: 0 10px; }
  :root[data-theme] .topnav { min-width: 0; }
  :root[data-theme] .topnav a { padding: 4px 5px 5px; font-size: 14px; letter-spacing: 0.03em; }
  :root[data-theme] .rail-actions { flex: none; }
}
@media (min-width: 900px) and (max-width: 999px) {   /* a half-width window: the nine links must stay on one line */
  :root[data-theme] .bar { gap: 0 6px; }
  :root[data-theme] .topnav a { padding: 4px 3px 5px; font-size: 13px; letter-spacing: 0.01em; }
  :root[data-theme] .tseg button { padding: 0 8px; }
}

/* ------------------------------------------------------------ the home page, laid out like the 4th artifact @map:home-4 (markup: site/hubs.py home_html) */
:root[data-theme] .hm4-hero { display: grid; grid-template-columns: minmax(0, 1.4fr) minmax(0, 1fr); gap: 48px; align-items: end; padding: 38px 0 34px; }
:root[data-theme] .hm4-kick { margin: 0 0 12px; font-variant: small-caps; letter-spacing: 0.12em; color: var(--qb-text-muted); }
:root[data-theme] .hm4-hero h1 { margin: 0 0 16px; font-size: clamp(34px, 4.8vw, 54px); line-height: 1.06; letter-spacing: -0.025em; font-weight: 700; }
:root[data-theme] .hm4-lead { max-width: 36em; margin: 0 0 22px; font-size: 1.1em; }
:root[data-theme] .hm4-cta { display: flex; flex-wrap: wrap; gap: 14px 24px; align-items: center; margin: 0; }
:root[data-theme] .hm4-cta .btn { padding: 0 22px; height: 48px; display: inline-flex; align-items: center; text-decoration: none; }
:root[data-theme] .hm4-ledger { list-style: none; margin: 0; padding: 0; }
:root[data-theme] .hm4-ledger li { border-top: 2px solid var(--qb-text-heading); padding: 8px 0 6px; }
:root[data-theme] .hm4-ledger a { display: flex; align-items: baseline; gap: 18px; color: inherit; text-decoration: none; }
:root[data-theme] .hm4-ledger a:hover b, :root[data-theme] .hm4-ledger a:focus-visible b { text-decoration: underline; text-decoration-thickness: 3px; text-underline-offset: 5px; }
:root[data-theme] .hm4-ledger b { min-width: 3.4ch; font-size: clamp(36px, 5vw, 52px); line-height: 1; letter-spacing: -0.02em; font-weight: 700; }
:root[data-theme] .hm4-ledger span { font-variant: small-caps; letter-spacing: 0.1em; color: var(--qb-text-muted); }
:root[data-theme] .hm4-two { display: grid; grid-template-columns: minmax(0, 1.15fr) minmax(0, 1fr); gap: 44px; border-top: 5px solid var(--qb-text-heading); padding-top: 26px; align-items: start; }
:root[data-theme] .hm4-q { display: grid; grid-template-columns: minmax(64px, auto) minmax(0, 1fr); gap: 8px 16px; }
:root[data-theme] .hm4-qn b { display: block; font-size: clamp(48px, 6vw, 76px); line-height: 0.9; font-weight: 700; letter-spacing: -0.04em; }
:root[data-theme] .hm4-qn small { display: block; margin-top: 4px; font-size: 19px; line-height: 1.2; color: var(--qb-text-secondary); }
:root[data-theme] .hm4-meta { display: flex; flex-wrap: wrap; gap: 4px 14px; align-items: center; font-variant: small-caps; letter-spacing: 0.08em; color: var(--qb-text-muted); }
:root[data-theme] .hm4-meta .mk { font: 500 0.92em var(--f-mono); font-variant: normal; letter-spacing: 0; color: var(--qb-text-primary); }
:root[data-theme] .hm4-meta .dot { display: inline-block; width: 8px; height: 8px; margin-right: 6px; background: var(--sub, var(--qb-accent)); }
:root[data-theme] .hm4-q .qt { margin: 8px 0 14px; font-size: 1.04em; }
:root[data-theme] .hm4-q .answer { margin: 16px 0; }
:root[data-theme] .hm4-tool { border-top: 5px solid var(--qb-text-heading); align-self: start; }
:root[data-theme] .hm4-toolhead { display: flex; flex-wrap: wrap; justify-content: space-between; align-items: center; gap: 6px 14px; padding: 10px 0 6px; }
:root[data-theme] .hm4-toolhead h2 { margin: 0; font-size: 1.4em; font-weight: 700; }
:root[data-theme] .hm4-lamp { display: inline-flex; align-items: center; gap: 6px; font: 500 11px/1 var(--f-mono); letter-spacing: 0.1em; text-transform: uppercase; color: var(--qb-text-secondary); }
:root[data-theme] .hm4-lamp i { width: 7px; height: 7px; border-radius: 50% !important; background: var(--lamp); box-shadow: 0 0 5px var(--lamp) !important; }
:root[data-theme] .hm4-toolbody .flab { font-variant: small-caps; letter-spacing: 0.1em; color: var(--qb-text-muted); }
:root[data-theme] .hm4-typed { margin: 4px 0 8px; padding: 2px 0; font: 400 1.2em/1.4 var(--f-mono); border-bottom: 2px solid var(--qb-text-heading); }
:root[data-theme] .hm4-out .tool-out, :root[data-theme] .hm4-out .tool-sample { margin: 0; }
:root[data-theme] .hm4-more { margin: 12px 0 0; font-size: 0.95em; color: var(--qb-text-muted); }
/* the subject cards: a rule, a square in the subject's colour, the name, the counts */
:root[data-theme] .hm4-block { margin: 40px 0 0; border-top: 5px solid var(--qb-text-heading); padding-top: 22px; }
:root[data-theme] .hm4-block h2, :root[data-theme] .hm4-three h2 { margin: 0 0 10px; font-size: 1.5em; font-weight: 700; letter-spacing: -0.01em; }
:root[data-theme] .bento { display: grid; grid-template-columns: repeat(auto-fill, minmax(260px, 1fr)); gap: 0 32px; }
:root[data-theme] .bento .sub-card { grid-column: auto !important; grid-row: auto !important; display: block; min-height: 0; padding: 12px 0; background: none; border: 0; border-top: 2px solid var(--qb-text-heading); }
:root[data-theme] .bento .sub-card .ic, :root[data-theme] .bento .sub-card .blurb, :root[data-theme] .bento .sub-card .chips { display: none; }
:root[data-theme] .bento .sub-card h3 { display: flex; align-items: baseline; gap: 10px; margin: 0; font-size: 1.15em; font-weight: 700; }
:root[data-theme] .bento .sub-card h3::before { content: ""; flex: none; width: 0.7em; height: 0.7em; background: var(--sub, var(--qb-accent)); }
:root[data-theme] .bento .sub-card .meta { display: block; margin: 2px 0 0 calc(0.7em + 10px); color: var(--qb-text-muted); font-size: 0.92em; }
:root[data-theme] .bento .sub-card:hover h3 { text-decoration: underline; text-decoration-thickness: 2px; text-underline-offset: 3px; }
:root[data-theme] .hm4-three { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 36px; border-top: 5px solid var(--qb-text-heading); padding-top: 22px; margin-top: 40px; }
:root[data-theme] .hm4-three p { margin: 0 0 14px; }
:root[data-theme] .hm4-three .btn { display: inline-flex; align-items: center; padding: 0 22px; text-decoration: none; }
:root[data-theme] .home-about > .about { margin-top: 36px; color: var(--qb-text-muted); font-size: 0.95em; }
:root[data-theme] .home-howto, :root[data-theme] .home-about > section:not(.hm4-two):not(.hm4-block):not(.hm4-three) { margin-top: 40px; }
@media (max-width: 860px) {
  :root[data-theme] .hm4-hero, :root[data-theme] .hm4-two { grid-template-columns: minmax(0, 1fr); gap: 28px; }
  :root[data-theme] .hm4-hero { padding-top: 26px; }
}
/* inner boxes that carried their own side padding sit flush with the column */
:root[data-theme] .pg-hero, :root[data-theme] .hero { padding-left: 0; padding-right: 0; }

/* ------------------------------------------------------------ headings: real serif headings as in the artifact; only a side card's title stays a small label */
:root[data-theme] main h2, :root[data-theme] .home-about h2, :root[data-theme] .bs-card h2, :root[data-theme] main.page h2 {
  margin: 28px 0 8px; font: 700 1.5em/1.2 var(--f-text); letter-spacing: -0.01em; text-transform: none; color: var(--qb-text-heading); }
:root[data-theme] main.page .sidecard h2, :root[data-theme] .chcard-head h2, :root[data-theme] .tool-sample-head .eyebrow {
  margin: 0; font: 700 14px/1.3 var(--f-text); font-variant: small-caps; letter-spacing: 0.12em; text-transform: none; color: var(--qb-text-muted); }
:root[data-theme] .fgroup h3, :root[data-theme] .flist-group h3 { font: 500 15px/1.3 var(--f-text); font-variant: small-caps; letter-spacing: 0.1em; text-transform: none; color: var(--qb-text-muted); }
:root[data-theme] .hm4-toolhead h2 { margin: 0; font-size: 1.4em; }
:root[data-theme] .hm4-block h2, :root[data-theme] .hm4-three h2 { margin: 0 0 10px; }
/* a tool's worked result is a readout: dark panel, lamp-green figures in mono, no inner boxes */
:root[data-theme] .hm4-out .bs-scroll, :root[data-theme] .hm4-out table { width: 100%; }

/* ------------------------------------------------------------ the question list: every question in its own box @map:list-boxes (rows are drawn by site.js cardHtml) */
:root[data-theme] .cards { gap: 12px; }
:root[data-theme] .cardrow { gap: 0; background: transparent; border: 1px solid var(--qb-border-strong); }
:root[data-theme] .cardrow:hover, :root[data-theme] .cardrow:focus-within { border-color: var(--qb-text-heading); }
:root[data-theme] .cardrow .card { border: 0; background: none; }
:root[data-theme] .cardrow .pick { width: 50px; background: none; border: 0; border-left: 1px solid var(--qb-border); }
:root[data-theme] .cardrow .pick[aria-pressed="true"] { background: var(--qb-accent-tint); border-left-color: var(--qb-border-strong); }
:root[data-theme] .card .badge b { font: 700 21px/1 var(--f-text); }
:root[data-theme] .card .badge span { font: 500 12px/1.2 var(--f-mono); color: var(--qb-text-muted); }
:root[data-theme] .card .body { padding: 14px 16px 14px 6px; gap: 8px; }
:root[data-theme] .card .snippet { font-size: 1.04em; }

/* ------------------------------------------------------------ boxes that were only a rule on top sit flush with the column (no inset text) */
:root[data-theme] .chcard, :root[data-theme] .q-card, :root[data-theme] .bs-card, :root[data-theme] .sidecard, :root[data-theme] .feature, :root[data-theme] .kpi, :root[data-theme] .sub-card.big { padding-left: 0; padding-right: 0; }
:root[data-theme] .chcard-head { padding-left: 0; }
/* a year tile: a hairline box; the board paper of the year gets the turmeric tint (the one accent), never a subject colour */
:root[data-theme] .yp { background: none; border: 1px solid var(--qb-border-strong); }
:root[data-theme] .yp:hover { border-color: var(--qb-text-heading); }
:root[data-theme] .yp.board { background: var(--qb-accent-tint); border-color: var(--qb-text-heading); }
:root[data-theme] .yp.board span { color: var(--qb-text-heading); font-weight: 700; }
:root[data-theme] .yp b { font-weight: 700; }

/* a tool's final answer is a readout wherever it appears: the card that holds the answer list becomes the dark panel with mono figures @map:readout */
:root[data-theme] .bs-card:has(> .bs-answer) { background: var(--panel); color: var(--panel-ink); border: 0; padding: 14px 18px 8px; margin-bottom: 18px; --qb-text-primary: var(--panel-ink); --qb-text-heading: var(--panel-ink);
  --qb-text-secondary: var(--panel-2); --qb-text-muted: var(--panel-muted); --qb-border: var(--panel-line); --qb-link: var(--panel-ink); --qb-code-bg: var(--panel-code); }
:root[data-theme] .bs-card:has(> .bs-answer) { outline: 1px solid var(--panel-edge); outline-offset: -1px; }
:root[data-theme="silver"] .bs-card:has(> .bs-answer) { border-top: 2px solid var(--qb-text-heading); }
:root[data-theme] .bs-card:has(> .bs-answer) > h2 { margin: 0 0 10px; font: 500 11px/1 var(--f-mono); letter-spacing: 0.14em; text-transform: uppercase; color: var(--panel-accent); }
:root[data-theme] .bs-card:has(> .bs-answer) .bs-answer dd.big, :root[data-theme] .bs-card:has(> .bs-answer) .bs-answer .big { color: var(--panel-accent); }
:root[data-theme] .bs-card:has(> .bs-answer) .bs-answer dt { color: var(--panel-muted); }
:root[data-theme] .hm4-out .bs-result { display: block; margin: 0; column-count: 1; }
:root[data-theme] .hm4-out .bs-card { width: auto; max-width: none; }
:root[data-theme] .hm4-out .bs-card:not(:has(> .bs-answer)) h2 { font-size: 1.2em; margin-top: 18px; }
:root[data-theme] .hm4-search { display: flex; gap: 10px; align-items: flex-end; max-width: 34em; margin: 0 0 18px; }
:root[data-theme] .hm4-search input { flex: 1; min-width: 0; height: 48px; padding: 0 2px; background: transparent; border: 0; border-bottom: 2px solid var(--qb-text-heading); border-radius: 0; font-size: 1em; color: var(--qb-text-primary); }
:root[data-theme] .hm4-search .btn { height: 48px; padding: 0 20px; }
@media (min-width: 900px) { :root[data-theme] .hm4-search { display: none; } }          /* the header's own search strip is there */

/* ------------------------------------------------------------ picture boxes: no white card. A raster diagram (the logic circuits qh/circuit.py draws, the AI-made diagrams of the Diagrams tab) takes the page by
   blending: multiply on paper (white vanishes), and in the dark theme or the dark readout panel invert it first and screen it (black vanishes) @map:brand-diagrams */
:root[data-theme] .bs-paper { background: transparent; padding: 0; border-radius: 0; }
/* a drawing the server makes (K-map, tree, structure, ray diagram...) takes the page too: site.css gives .fig.drawn a white card, and in the dark theme or the dark
   answer panel the flipped (light) ink would sit on white and vanish */
:root[data-theme] .fig.drawn { background: transparent; border: 0; padding: 0; }
:root[data-theme] .bs-paper img, :root[data-theme] .fig img[alt^="Diagram for this answer"] { mix-blend-mode: multiply; border-radius: 0; }
:root[data-theme="glass"] .bs-paper img, :root[data-theme="glass"] .fig img[alt^="Diagram for this answer"] {
  filter: invert(1) hue-rotate(180deg); mix-blend-mode: screen; }
:root[data-theme] main, :root[data-theme] main.page { z-index: auto; }   /* a stacking context here would keep a picture from blending with the page behind it */

/* ------------------------------------------------------------ small fixes of the 2026-10-17 hunts */
/* the open question's title (subject, year, paper number) wraps to a second line instead of "Chemistry · 20…" (B1.j) */
:root[data-theme] .dialog-title { white-space: normal; line-height: 1.25; font-size: 14px; overflow: visible; text-overflow: clip; overflow-wrap: anywhere; }
/* tablets (600-899px) get the phone layout, whose header had no search: the only search was on the home page and the list (B2.b) */
@media (min-width: 600px) and (max-width: 899px) {
  :root[data-theme] .top { display: flex; align-items: center; gap: 12px; padding: 12px 24px 0; }
  :root[data-theme].is-list .top { display: none; }
  :root[data-theme] .tsearch { height: 40px; max-width: none; }
}
/* the examples under the home search box (the placeholder is short now: a long one was cut off on a phone) */
:root[data-theme] .hm4-try { margin: -6px 0 18px; font-size: 15px; color: var(--qb-text-muted); }
:root[data-theme] .hm4-try a { color: var(--qb-text-primary); text-decoration: underline; text-underline-offset: 3px; }
@media (min-width: 900px) { :root[data-theme] .hm4-try { display: none; } }          /* with the hero search box: the header's own search is there */

/* ------------------------------------------------------------ the home page on a phone @map:home-phone (markup: site/hubs.py home_html; owner, 2026-10-18)
   One column, read in the order a student uses it: what this is, the numbers, the search, the subjects (two to a row), the three things to do, then the sample
   question and the tool. The hero's two wrappers dissolve (display: contents) so the subjects can sit between the search and the links; the markup keeps its desktop order. */
:root[data-theme] .hm4-block .hm-pills { display: none; }                    /* the subject cards below say the same; the scrolling pill row hid most of them */
:root[data-theme] .bento .sub-card .mq { display: inline; }                  /* site.css hid it on a phone when it held the board and the questions together */
@media (max-width: 640px) {
  :root[data-theme] .home-about { gap: 0; }
  :root[data-theme] .home-about > * { order: 20; }
  :root[data-theme] .hm4-hero, :root[data-theme] .hm4-hero > div { display: contents; }
  :root[data-theme] .hm4-x { display: none; }                                /* the long half of the kicker and of the lead: the links below say it */
  :root[data-theme] .hm4-kick { order: 1; margin: 20px 0 8px; font-size: 13px; letter-spacing: 0.1em; }
  :root[data-theme] .hm4-hero h1 { order: 2; margin: 0 0 12px; font-size: 31px; line-height: 1.08; }
  :root[data-theme] .hm4-lead { order: 3; margin: 0 0 18px; font-size: 16.5px; line-height: 1.5; }
  /* the numbers as one strip of four under a rule each */
  :root[data-theme] .hm4-ledger { order: 4; display: grid; grid-template-columns: repeat(4, minmax(0, 1fr)); gap: 0 12px; margin: 0 0 22px; }
  :root[data-theme] .hm4-ledger li { padding: 8px 0 0; }
  :root[data-theme] .hm4-ledger a { display: block; }
  :root[data-theme] .hm4-ledger b { display: block; min-width: 0; font-size: 26px; }
  :root[data-theme] .hm4-ledger span { display: block; margin-top: 3px; font-size: 12px; line-height: 1.2; letter-spacing: 0.06em; }
  :root[data-theme] .hm4-search { order: 5; width: 100%; margin: 0 0 12px; }
  :root[data-theme] .hm4-try { order: 6; margin: 0; }
  /* the subjects: two to a row, each a framed tap target with the subject's stripe (as in the question list); an odd last one takes the full row */
  :root[data-theme] .hm4-block { order: 7; margin: 28px 0 0; padding-top: 14px; }
  :root[data-theme] .hm4-block h2 { margin: 0 0 12px; font-size: 1.3em; }
  :root[data-theme] .bento { grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 10px; }
  :root[data-theme] .bento .sub-card { min-height: 84px; padding: 11px 12px 12px 14px; border: 1px solid var(--qb-border-strong); border-left: 5px solid var(--sub, var(--qb-accent)); }
  :root[data-theme] .bento .sub-card:last-child:nth-child(odd) { grid-column: 1 / -1 !important; }
  :root[data-theme] .bento .sub-card h3 { display: block; margin: 0 0 6px; font-size: 17px; line-height: 1.15; }
  :root[data-theme] .bento .sub-card h3::before { display: none; }
  :root[data-theme] .bento .sub-card .meta { margin: 0; font-size: 13.5px; line-height: 1.35; }
  :root[data-theme] .bento .sub-card .mb, :root[data-theme] .bento .sub-card .ms { display: none; }
  :root[data-theme] .bento .sub-card .mq, :root[data-theme] .bento .sub-card .mp { display: block; }
  /* the three things to do: full-width rows */
  :root[data-theme] .hm4-cta { order: 8; display: grid; grid-template-columns: minmax(0, 1fr); gap: 10px; margin: 22px 0 0; }
  :root[data-theme] .hm4-cta > a { display: flex; align-items: center; justify-content: space-between; height: 54px; padding: 0 16px; font-size: 17px; font-weight: 600; text-decoration: none; }
  :root[data-theme] .hm4-cta .btn.primary { justify-content: flex-start; }
  :root[data-theme] .hm4-cta .hm4-go { color: var(--qb-text-heading); border: 1px solid var(--qb-text-heading); }
  :root[data-theme] .hm4-cta .hm4-go::after { content: "\2192"; }
  /* the sample question: its printed number on a line with the facts, then the text and the answer across the whole column (a code line with no spaces used to run off the screen) */
  :root[data-theme] .hm4-two { order: 9; margin-top: 34px; gap: 34px; }
  :root[data-theme] .hm4-q { grid-template-columns: minmax(0, 1fr); gap: 4px; }
  :root[data-theme] .hm4-qn { display: flex; align-items: baseline; gap: 8px; }
  :root[data-theme] .hm4-qn b { font-size: 44px; }
  :root[data-theme] .hm4-qn small { margin: 0; font-size: 18px; }
  :root[data-theme] .hm4-q .qt { overflow-wrap: anywhere; }
  :root[data-theme] .hm4-three { order: 10; margin-top: 34px; }
}

/* note boxes are smaller than tool boxes: shorter title and text, the text cut at 3 lines (2026-10-20) @map:note-versions */
:root[data-theme] .tc-group .tcard > span:not(.tc-head):not(.ic) { padding: 9px 12px 10px; }
:root[data-theme] .tc-group .tcard .tc-head { padding: 4px 10px; font-size: 10px; letter-spacing: 0.03em; gap: 6px; white-space: nowrap; }
:root[data-theme] .tc-group .tcard b { font-size: 17px; margin-bottom: 3px; }
:root[data-theme] .tc-group .tcard .d { font-size: 14px; line-height: 1.4; display: -webkit-box; -webkit-line-clamp: 3; -webkit-box-orient: vertical; overflow: hidden; }
:root[data-theme] .tc-group .tc-versions { padding: 5px 12px; }
:root[data-theme] .tgrid:has(.tc-group) { grid-template-columns: repeat(auto-fill, minmax(230px, 1fr)); gap: 10px; }

/* the other versions of a program, along the bottom of its box (pages.note_cards) @map:note-versions */
:root[data-theme] .tc-versions { border: 1px solid var(--qb-text-heading); border-radius: 0; margin-top: -1px; padding: 8px 14px; gap: 6px 14px;
  font: 500 12.5px/1.4 var(--f-mono); color: var(--qb-text-muted); }
:root[data-theme] .tc-versions span { font: 500 11.5px/1.4 var(--f-mono); letter-spacing: 0.1em; text-transform: uppercase; }
:root[data-theme] .tc-versions a { color: var(--qb-text-heading); font-weight: 600; text-decoration: underline; text-underline-offset: 3px; }
:root[data-theme] .tc-versions a:hover { background: var(--qb-accent); color: #1C1B18; text-decoration: none; }

/* ------------------------------------------------------------ Back and Redo, top left of every page @map:nav-buttons (markup in templates/page.html and index.html, behaviour in common.js) */
.navbtns { display: flex; align-items: center; gap: 2px; flex: none; }
:root[data-theme] .navbtns button { display: inline-flex; align-items: center; gap: 3px; height: 34px; min-width: 34px; justify-content: center; padding: 0 6px; border: 0; background: none; color: var(--qb-text-heading);
  font: 500 14px/1 var(--f-text); font-variant: small-caps; letter-spacing: 0.08em; cursor: pointer; }
:root[data-theme] .navbtns button span { display: none; }
:root[data-theme] .navbtns button:not(:disabled):hover { text-decoration: underline; text-underline-offset: 3px; }
:root[data-theme] .navbtns button:disabled { opacity: 0.32; cursor: default; }
@media (min-width: 900px) {
  :root[data-theme] .navbtns { position: absolute; top: 0; left: -6px; z-index: 17; height: 28px; }
  :root[data-theme] .navbtns button { height: 28px; }
  :root[data-theme] .navbtns button span { display: inline; }
  :root[data-theme] .top { pointer-events: none; }     /* the search strip spans the column, over the buttons: only its own search box and link take clicks */
  :root[data-theme] .top > * { pointer-events: auto; }
}

/* Sign in / Sign out (@map:google-signin): small-caps text like the About link, shown by common.js once /auth/me answers */
:root[data-theme] .acct { margin-left: 14px; padding: 0; border: 0; background: none; font: 500 14px/1 var(--f-text); font-variant: small-caps; letter-spacing: 0.08em;
  color: var(--qb-text-secondary); text-decoration: underline; text-underline-offset: 3px; cursor: pointer; white-space: nowrap; }
:root[data-theme] .acct:hover { color: var(--qb-text-heading); }
:root[data-theme] .acct[hidden] { display: none; }
@media (max-width: 899px) {
  :root[data-theme] .acct { margin: 4px 0 0 6px; text-align: left; font-size: 13px; letter-spacing: 0.04em; }
  :root[data-theme] #pk-streak { display: none; }      /* @map:daily-practice: on a phone the header has room for Account and Sign out only; the streak is on /daily and the account page */
}

/* @map:visitor-data: the signed-in controls under a question (acct-*.js each add one child): Save and My note share a row, the progress buttons take the next, an open note takes a whole row */
.q-acct { display: flex; flex-wrap: wrap; align-items: center; gap: 10px 12px; margin: 14px 0; }
.q-acct:empty { display: none; }
.q-acct > * { margin: 0 !important; }
.q-acct > .pgs { flex: 1 1 100%; }
.q-acct > .q-note:has(.q-note-panel:not([hidden])) { flex: 1 1 100%; }
.q-acct > .pk-save { order: 1; }
.q-acct > .q-note { order: 2; }
.q-acct > .pgs { order: 3; }