/* ==========================================================================
   PhysicsDNA - main stylesheet
   A physics textbook page: navy on paper, cobalt for trust, amber for energy.
   Sections: 1 tokens · 2 base · 3 header/footer · 4 post layout · 5 components
             6 pattern blocks · 7 WordPress core blocks · 8 archives/cards
             9 search/404/comments/page · 10 format tweaks · 11 utilities
   ========================================================================== */

/* 1. Tokens ---------------------------------------------------------------- */
:root{
  --paper:#FFFFFF; --surface:#FFFFFF; --sunk:#F5F7FA; --tint:#F8F9FB;
  --ink:#14213D; --ink-2:#36435C; --muted:#667189; --line:#E6EAF0; --grid:rgba(36,83,214,.05);
  --accent:#2453D6; --accent-ink:#FFFFFF; --accent-soft:#E7EDFC;
  --signal:#E89B2C; --signal-soft:#FDF1DD;
  --good:#16805A; --good-soft:#E3F4EC; --bad:#C2413A; --bad-soft:#FBE8E6;
  --band:#0D1B33; --band-2:#152645; --band-ink:#F2F5FB; --band-muted:#A9B6CE; --band-line:#263A60;
  --t-concept:#2453D6; --t-num:#16805A; --t-mistake:#C2413A; --t-book:#C98A1E; --t-road:#7A4FD1; --t-answer:#0E7C86; --t-platform:#3B5B8C; --t-exam:#B5462F; --t-notes:#2453D6;
  --t-diary:color-mix(in srgb,var(--t-mistake) 78%,var(--signal));
  --type:var(--accent);
  --shadow:0 1px 2px rgba(13,27,51,.04),0 8px 24px -12px rgba(13,27,51,.12);
  --f-display:"Newsreader","Iowan Old Style","Georgia",serif;
  --f-body:"Instrument Sans",system-ui,-apple-system,"Segoe UI",sans-serif;
  --f-mono:"JetBrains Mono",ui-monospace,"SFMono-Regular",Menlo,monospace;
  --f-hand:"Caveat","Segoe Print","Bradley Hand",cursive;
  --wrap:1280px; --gut:clamp(16px,4vw,40px); --r:14px;
}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]){
  --paper:#0B1220; --surface:#101A2C; --sunk:#0D1627; --tint:#0E1829;
  --ink:#E9EEF8; --ink-2:#C9D3E6; --muted:#93A1BB; --line:#1F2D47; --grid:rgba(124,156,255,.07);
  --accent:#7C9CFF; --accent-ink:#0A111F; --accent-soft:#17264A;
  --signal:#F2B456; --signal-soft:#2E2414;
  --good:#4CC994; --good-soft:#12301F; --bad:#F08077; --bad-soft:#36191A;
  --band:#111E36; --band-2:#16264A; --band-ink:#EEF2FA; --band-muted:#9BAACA; --band-line:#263A60;
  --t-concept:#7C9CFF; --t-num:#4CC994; --t-mistake:#F08077; --t-book:#F2B456; --t-road:#B39BFF; --t-answer:#4FC7CF; --t-platform:#8EA9D8; --t-exam:#F0907A; --t-notes:#7C9CFF;
  --shadow:0 1px 2px rgba(0,0,0,.3),0 8px 24px -12px rgba(0,0,0,.5);
  color-scheme:dark}}
:root[data-theme="dark"]{
  --paper:#0B1220; --surface:#101A2C; --sunk:#0D1627; --tint:#0E1829;
  --ink:#E9EEF8; --ink-2:#C9D3E6; --muted:#93A1BB; --line:#1F2D47; --grid:rgba(124,156,255,.07);
  --accent:#7C9CFF; --accent-ink:#0A111F; --accent-soft:#17264A;
  --signal:#F2B456; --signal-soft:#2E2414;
  --good:#4CC994; --good-soft:#12301F; --bad:#F08077; --bad-soft:#36191A;
  --band:#111E36; --band-2:#16264A; --band-ink:#EEF2FA; --band-muted:#9BAACA; --band-line:#263A60;
  --t-concept:#7C9CFF; --t-num:#4CC994; --t-mistake:#F08077; --t-book:#F2B456; --t-road:#B39BFF; --t-answer:#4FC7CF; --t-platform:#8EA9D8; --t-exam:#F0907A; --t-notes:#7C9CFF;
  --shadow:0 1px 2px rgba(0,0,0,.3),0 8px 24px -12px rgba(0,0,0,.5);
  color-scheme:dark}
:root[data-theme="light"]{color-scheme:light}

/* format colour on <body> (also printed inline by PHP) */
.pd-format-concept{--type:var(--t-concept)} .pd-format-numericals{--type:var(--t-num)} .pd-format-mistakes{--type:var(--t-mistake)}
.pd-format-book-review,.pd-format-book-comparison{--type:var(--t-book)} .pd-format-roadmap{--type:var(--t-road)}
.pd-format-answer-writing{--type:var(--t-answer)} .pd-format-platform-review{--type:var(--t-platform)} .pd-format-exam-update{--type:var(--t-exam)}
.pd-format-notes{--type:var(--t-notes)} .pd-format-mind-map{--type:var(--t-road)} .pd-format-pyq{--type:var(--t-num)}
.pd-format-practical,.pd-format-derivation{--type:var(--t-answer)} .pd-format-diary{--type:var(--t-diary)}

/* 2. Base ------------------------------------------------------------------ */
*,*::before,*::after{box-sizing:border-box}
[hidden]{display:none!important}
html{scroll-behavior:smooth;scroll-padding-top:96px;-webkit-text-size-adjust:100%}
body{margin:0;background:var(--paper);color:var(--ink-2);font-family:var(--f-body);font-size:16px;line-height:1.7;-webkit-font-smoothing:antialiased;overflow-x:hidden}
a{color:inherit;text-decoration:none}
button{font:inherit;color:inherit;cursor:pointer;background:none;border:0;padding:0}
img,svg,video{max-width:100%}
img{height:auto}
:focus-visible{outline:2px solid var(--accent);outline-offset:3px;border-radius:6px}
.wrap{max-width:var(--wrap);margin-inline:auto;padding-inline:var(--gut)}
h1,h2,h3,h4,h5,h6{color:var(--ink);font-family:var(--f-display);font-weight:400;letter-spacing:-.012em;text-wrap:balance;margin:0;line-height:1.15}
p{margin:0}
hr{border:0;border-top:1px solid var(--line);margin:2em 0}
.mono{font-family:var(--f-mono)}
.eyebrow{font-family:var(--f-mono);font-size:.72rem;letter-spacing:.12em;text-transform:uppercase;color:var(--muted)}
.lede{color:var(--muted);font-size:1.075rem;max-width:58ch}
em.hl{font-style:italic;color:var(--accent)}
.link-arrow{color:var(--accent);font-weight:600;display:inline-flex;gap:8px;align-items:center}
.link-arrow svg{transition:transform .2s}
.link-arrow:hover svg{transform:translateX(3px)}
.pd-small{font-size:.86rem}
.screen-reader-text{border:0;clip:rect(1px,1px,1px,1px);clip-path:inset(50%);height:1px;margin:-1px;overflow:hidden;padding:0;position:absolute!important;width:1px;word-wrap:normal!important}
.screen-reader-text:focus{background:var(--surface);color:var(--ink);clip:auto!important;clip-path:none;display:block;height:auto;left:8px;top:8px;padding:12px 18px;width:auto;z-index:100000;border-radius:10px;box-shadow:var(--shadow);font-weight:600}
.skip-link{position:absolute;left:-9999px;top:8px;z-index:100000;background:var(--accent);color:var(--accent-ink);padding:10px 16px;border-radius:10px;font-weight:600}
.skip-link:focus{left:8px}

.btn{display:inline-flex;align-items:center;justify-content:center;gap:9px;padding:12px 20px;border-radius:999px;font-weight:600;font-size:.93rem;line-height:1.3;border:1px solid transparent;transition:transform .2s,border-color .2s,background .2s,box-shadow .2s;white-space:nowrap;cursor:pointer;text-decoration:none}
.btn svg{transition:transform .2s;flex:none}
.btn-primary{background:var(--accent);color:var(--accent-ink);box-shadow:0 6px 18px -8px var(--accent)}
.btn-primary:hover{transform:translateY(-1px)}
.btn-ghost{border-color:var(--line);background:var(--surface);color:var(--ink)}
.btn-ghost:hover{border-color:var(--accent);color:var(--accent)}
.btn-signal{background:var(--signal);color:#1A1205}
.btn-sm{padding:8px 14px;font-size:.85rem}
.chip{display:inline-block;font-family:var(--f-mono);font-size:.7rem;line-height:1.5;padding:4px 10px;border-radius:999px;background:var(--sunk);color:var(--ink-2);border:1px solid var(--line);white-space:nowrap}
a.chip:hover{border-color:var(--accent);color:var(--accent)}
.chips{display:flex;flex-wrap:wrap;gap:6px}
.icon-btn{width:40px;height:40px;border-radius:10px;border:1px solid var(--line);background:var(--surface);display:grid;place-items:center;color:var(--ink);flex:none}
.icon-btn:hover{border-color:var(--accent)}
input[type=range]{-webkit-appearance:none;appearance:none;width:100%;height:6px;border-radius:99px;background:linear-gradient(90deg,var(--accent) var(--p,50%),var(--line) var(--p,50%))}
input[type=range]::-webkit-slider-thumb{-webkit-appearance:none;width:18px;height:18px;border-radius:50%;background:var(--surface);border:2px solid var(--accent)}
input[type=range]::-moz-range-thumb{width:16px;height:16px;border-radius:50%;background:var(--surface);border:2px solid var(--accent)}
mjx-container{color:var(--ink)}
mjx-container[display="true"]{overflow-x:auto;overflow-y:hidden;max-width:100%;padding-block:2px}

/* 3. Header + footer ---------------------------------------------------------- */
.progress{position:fixed;top:0;left:0;height:3px;width:0;background:var(--type,var(--accent));z-index:80;transition:width .1s linear;pointer-events:none}
.notice{background:var(--band);color:var(--band-ink);font-size:.85rem;position:relative}
.notice .wrap{display:flex;justify-content:center;align-items:center;gap:12px;padding-block:9px;text-align:center;flex-wrap:wrap;padding-right:calc(var(--gut) + 36px)}
.notice b,.notice strong{color:var(--signal);font-weight:600}
.notice a{text-decoration:underline;text-underline-offset:3px;text-decoration-color:var(--band-muted)}
.notice-close{position:absolute;right:calc(var(--gut) - 8px);top:50%;transform:translateY(-50%);width:32px;height:32px;border-radius:8px;display:grid;place-items:center;color:var(--band-muted)}
.notice-close:hover{color:var(--band-ink);background:rgba(255,255,255,.08)}
header.nav{position:sticky;top:0;z-index:50;background:color-mix(in srgb,var(--paper) 86%,transparent);backdrop-filter:saturate(1.4) blur(14px);-webkit-backdrop-filter:saturate(1.4) blur(14px);border-bottom:1px solid var(--line)}
.admin-bar header.nav{top:32px}
@media (max-width:782px){.admin-bar header.nav{top:46px}}
@media (max-width:600px){.admin-bar header.nav{top:0}}
.nav .wrap{display:flex;align-items:center;gap:24px;height:70px}
.logo{display:flex;align-items:center;gap:10px;font-weight:700;font-size:1.15rem;letter-spacing:-.01em;color:var(--ink);flex:none}
.logo b{color:var(--accent);font-weight:700}
.pd-custom-logo img{max-height:44px;width:auto;display:block}
/* Logo that follows light / dark mode */
.pd-custom-logo .custom-logo-link{display:block;line-height:0}
.pd-custom-logo .pd-logo-dark{display:none}
:root[data-theme="dark"] .pd-custom-logo .pd-logo-light{display:none}
:root[data-theme="dark"] .pd-custom-logo .pd-logo-dark{display:block}
@media (prefers-color-scheme:dark){
  :root:not([data-theme="light"]) .pd-custom-logo .pd-logo-light{display:none}
  :root:not([data-theme="light"]) .pd-custom-logo .pd-logo-dark{display:block}
}
/* single plain white logo: dark in light mode, original in dark mode */
.pd-logo-fix-white img{filter:brightness(0)}
:root[data-theme="dark"] .pd-logo-fix-white img{filter:none}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]) .pd-logo-fix-white img{filter:none}}
/* single plain dark logo: original in light mode, white in dark mode */
:root[data-theme="dark"] .pd-logo-fix-dark img{filter:brightness(0) invert(1)}
@media (prefers-color-scheme:dark){:root:not([data-theme="light"]) .pd-logo-fix-dark img{filter:brightness(0) invert(1)}}
.pd-primary{margin-left:auto;min-width:0}
.menu{display:flex;gap:2px;margin:0;list-style:none;padding:0}
.menu li{position:relative}
.menu a{display:block;padding:8px 12px;border-radius:8px;font-size:.93rem;color:var(--ink-2);font-weight:500;transition:background .15s,color .15s;white-space:nowrap}
.menu a:hover,.menu .current-menu-item>a,.menu .current-menu-ancestor>a,.menu .current_page_item>a{background:var(--sunk);color:var(--ink)}
.menu .sub-menu{display:none;position:absolute;top:100%;left:0;min-width:220px;list-style:none;margin:0;padding:8px;background:var(--surface);border:1px solid var(--line);border-radius:12px;box-shadow:var(--shadow);z-index:60}
.menu li:hover>.sub-menu,.menu li:focus-within>.sub-menu{display:block}
.menu .sub-menu .sub-menu{left:100%;top:0}
.nav-cta{display:flex;align-items:center;gap:10px}
.nav-cta .btn{padding:10px 18px}
.menu+.nav-cta{margin-left:4px}
.burger{display:none}
.mobile-panel{border-top:1px solid var(--line);background:var(--surface);max-height:calc(100vh - 70px);overflow-y:auto}
.mobile-panel ul{list-style:none;margin:0;padding:12px var(--gut) 20px;display:grid;gap:2px}
.mobile-panel ul ul{padding:0 0 0 16px}
.mobile-panel a{display:block;padding:12px 4px;border-bottom:1px solid var(--line);font-weight:500;color:var(--ink-2)}
.mobile-panel .btn{margin-top:12px;border:0;color:var(--accent-ink);display:flex}
.pd-foot-col{min-width:0}
@media (max-width:1060px){.pd-primary{display:none}.menu{display:none}.burger{display:grid}.nav-cta{margin-left:auto}}
@media (max-width:520px){.nav-cta .btn{display:none}.nav .wrap{gap:12px}}

footer.site-footer{border-top:1px solid var(--line);background:var(--tint);padding-block:56px 32px;font-size:.92rem;margin-top:0}
.foot{display:grid;grid-template-columns:1.4fr repeat(3,1fr);gap:32px}
.foot h2,.foot h4{font-family:var(--f-mono);font-size:.72rem;letter-spacing:.12em;text-transform:uppercase;color:var(--muted);font-weight:500;margin:0 0 14px}
.foot ul{list-style:none;padding:0;margin:0;display:grid;gap:9px}
.foot a{color:var(--ink-2)}
.foot a:hover{color:var(--accent)}
.foot .about p{color:var(--muted);max-width:34ch;margin-top:14px}
.foot .social{display:flex;gap:8px;margin-top:16px}
.legal{display:flex;justify-content:space-between;gap:12px;flex-wrap:wrap;margin-top:44px;padding-top:22px;border-top:1px solid var(--line);color:var(--muted);font-size:.82rem}
@media (max-width:820px){.foot{grid-template-columns:1fr 1fr}.foot .about{grid-column:span 2}}
@media (max-width:400px){.foot{grid-template-columns:1fr}.foot .about{grid-column:auto}}

/* 4. Post layout --------------------------------------------------------------- */
.site-main{display:block;min-height:50vh}
.post-head{padding-block:clamp(32px,5vw,56px) clamp(28px,4vw,40px);border-bottom:1px solid var(--line)}
.post-head .inner{max-width:880px;display:grid;gap:18px;min-width:0}
.crumbs{display:flex;flex-wrap:wrap;gap:8px;font-size:.84rem;color:var(--muted)}
.crumbs a:hover{color:var(--accent)}
.crumbs .sep{opacity:.5}
.crumbs .cur{color:var(--ink-2)}
.ptype{display:inline-flex;align-items:center;gap:8px;font-family:var(--f-mono);font-size:.72rem;letter-spacing:.1em;text-transform:uppercase;color:var(--type,var(--accent));background:color-mix(in srgb,var(--type,var(--accent)) 10%,transparent);border:1px solid color-mix(in srgb,var(--type,var(--accent)) 30%,transparent);padding:5px 11px;border-radius:999px;justify-self:start;line-height:1.4}
.ptype i{width:7px;height:7px;border-radius:50%;background:currentColor;flex:none}
a.ptype:hover{background:color-mix(in srgb,var(--type,var(--accent)) 16%,transparent)}
.post-head h1{font-size:clamp(2.1rem,4.6vw,3.5rem);line-height:1.08;overflow-wrap:break-word}
.dek{font-size:clamp(1.05rem,1.6vw,1.2rem);color:var(--muted);max-width:62ch}
.dek p+p{margin-top:.6em}
.post-head .meta{display:flex;flex-wrap:wrap;align-items:center;gap:10px 22px;font-size:.88rem;color:var(--muted);padding-top:6px}
.pd-meta .author{display:flex;align-items:center;gap:10px;color:var(--ink);font-weight:600}
.avatar{width:34px;height:34px;border-radius:50%;background:var(--accent-soft);color:var(--accent);display:grid;place-items:center;font-family:var(--f-display);font-style:italic;font-size:1rem;flex:none}
.post-head .meta .dot{width:3px;height:3px;border-radius:50%;background:var(--muted);opacity:.5}
.post-head .tldr{max-width:780px}

.post-grid{display:grid;grid-template-columns:200px minmax(0,1fr) 290px;gap:clamp(28px,4vw,56px);padding-block:40px 80px;align-items:start}
.post-grid.no-toc{grid-template-columns:minmax(0,1fr) 290px}
.toc{position:sticky;top:96px;display:grid;gap:12px;font-size:.86rem;min-width:0}
.toc ol{list-style:none;margin:0;padding:0;display:grid;gap:2px;border-left:1px solid var(--line)}
.toc a{display:block;padding:6px 0 6px 14px;margin-left:-1px;border-left:2px solid transparent;color:var(--muted);line-height:1.35;transition:color .15s,border-color .15s}
.toc a:hover{color:var(--ink)}
.toc a.on{color:var(--type,var(--accent));border-left-color:var(--type,var(--accent));font-weight:600}
.toc .time{font-family:var(--f-mono);font-size:.72rem;color:var(--muted)}
.toc:empty,.toc.is-empty{visibility:hidden}
.toc-mobile{display:none}
.toc-mobile details{border:1px solid var(--line);border-radius:12px;background:var(--tint)}
.toc-mobile summary{padding:12px 16px;font-weight:600;cursor:pointer;color:var(--ink);font-size:.95rem}
.toc-mobile ol{margin:0;padding:0 16px 14px 34px;display:grid;gap:4px;font-size:.92rem}
.toc-mobile a{color:var(--accent)}
.rail{position:sticky;top:96px;display:grid;gap:18px;min-width:0}
.admin-bar .toc,.admin-bar .rail{top:128px}
.pd-main-col{min-width:0;display:grid;gap:40px;align-content:start}
@media (max-width:1180px){.post-grid{grid-template-columns:minmax(0,1fr) 280px}.toc{display:none}.toc-mobile{display:block}}
@media (max-width:960px){.post-grid,.post-grid.no-toc{grid-template-columns:minmax(0,1fr)}.rail{position:static}}

/* article typography */
.pd-content{max-width:700px;min-width:0;font-size:calc(1.0625rem * var(--pd-scale,1));line-height:1.78;overflow-wrap:break-word}
.pd-content > *{margin-block:0}
.pd-content > * + *{margin-top:1.4em}
.pd-content h2{font-size:clamp(1.6rem,2.6vw,2.05rem);margin-top:2.4em;padding-top:.2em;scroll-margin-top:96px}
.pd-content h2 .n{font-family:var(--f-mono);font-size:.8rem;color:var(--type,var(--accent));display:block;margin-bottom:6px;letter-spacing:.08em}
.pd-content h3{font-size:1.3rem;margin-top:1.8em}
.pd-content h4{font-size:1.12rem;margin-top:1.6em}
.pd-content h2+*,.pd-content h3+*,.pd-content h4+*{margin-top:.8em}
.pd-content > :first-child{margin-top:0}
.pd-content p strong,.pd-content li strong{color:var(--ink)}
.pd-content a:not(.btn):not(.chip):not(.video):not(.wp-block-button__link){color:var(--accent);text-decoration:underline;text-decoration-thickness:1px;text-underline-offset:3px;text-decoration-color:color-mix(in srgb,var(--accent) 40%,transparent)}
.pd-content a:not(.btn):not(.chip):not(.video):not(.wp-block-button__link):hover{text-decoration-color:var(--accent)}
.pd-content ul,.pd-content ol{padding-left:1.3em}
.pd-content li+li{margin-top:.45em}
.pd-content ul li::marker{color:var(--accent)}
.pd-content ol li::marker{font-family:var(--f-mono);color:var(--accent);font-size:.88em}
.pd-content ul.clean{padding-left:1.1em;display:grid;gap:.5em}
.pd-content code,.pd-content kbd{font-family:var(--f-mono);font-size:.88em;background:var(--sunk);border:1px solid var(--line);border-radius:6px;padding:.08em .36em}
.pd-content pre{font-family:var(--f-mono);font-size:.88rem;background:var(--sunk);border:1px solid var(--line);border-radius:12px;padding:16px 18px;overflow-x:auto;line-height:1.6}
.pd-content pre code{background:none;border:0;padding:0}
.pd-content .pd-help,.pd-home .pd-help{display:none!important}
.pd-editor-note{font-size:.88rem;background:var(--signal-soft);border:1px dashed var(--signal);border-radius:10px;padding:10px 14px;color:var(--ink)}

/* 5. Components (from the post previews) --------------------------------------- */
.tldr{border:1px solid color-mix(in srgb,var(--accent) 28%,var(--line));background:var(--accent-soft);border-radius:16px;padding:22px 24px;display:grid;gap:10px}
.tldr .eyebrow{color:var(--accent)}
.tldr p{color:var(--ink);font-size:1.05rem}
.callout{border-radius:14px;padding:18px 20px 18px 22px;display:grid;gap:6px;border:1px solid var(--line);background:var(--tint);position:relative}
.callout b.t{font-family:var(--f-mono);font-size:.72rem;letter-spacing:.1em;text-transform:uppercase}
.callout.key b.t{color:var(--accent)}
.callout.warn{background:var(--signal-soft);border-color:color-mix(in srgb,var(--signal) 35%,transparent)}
.callout.warn b.t{color:var(--signal)}
.callout a{color:var(--accent);font-weight:600}
.eqn{background:var(--tint);border:1px solid var(--line);border-radius:14px;padding:18px 20px;overflow-x:auto;text-align:center;color:var(--ink)}
.eqn .tag{display:block;font-family:var(--f-mono);font-size:.7rem;color:var(--muted);text-align:left;margin-bottom:4px}
.sym{width:100%;border-collapse:collapse;font-size:.95rem}
.sym-wrap{overflow-x:auto;border:1px solid var(--line);border-radius:14px}
.sym th,.sym td{padding:11px 16px;text-align:left;border-bottom:1px solid var(--line)}
.sym tr:last-child td{border-bottom:0}
.sym th{font-family:var(--f-mono);font-size:.7rem;letter-spacing:.08em;text-transform:uppercase;color:var(--muted);font-weight:500;background:var(--tint)}
.sym td:first-child{color:var(--ink);white-space:nowrap}
.sym td:last-child{font-family:var(--f-mono);font-size:.85rem;white-space:nowrap}

.figure{border:1px solid var(--line);border-radius:18px;background:var(--surface);box-shadow:var(--shadow);overflow:hidden;margin-inline:0;min-width:0}
.fig-top,.fig-foot{display:flex;justify-content:space-between;align-items:center;gap:10px;flex-wrap:wrap;padding:11px 16px;font-family:var(--f-mono);font-size:.72rem;color:var(--muted)}
.fig-top{border-bottom:1px solid var(--line)}
.fig-top b{color:var(--ink);font-weight:500}
.fig-foot{border-top:1px solid var(--line);font-size:.7rem}
.cv,.canvas-wrap{background-image:linear-gradient(var(--grid) 1px,transparent 1px),linear-gradient(90deg,var(--grid) 1px,transparent 1px);background-size:22px 22px;position:relative}
.fig-ctrl{display:grid;grid-template-columns:1fr 1fr auto;gap:16px 22px;padding:16px;border-top:1px solid var(--line);align-items:end}
.ctrl{display:grid;gap:6px;min-width:0}
.ctrl label{display:flex;justify-content:space-between;font-size:.84rem;font-weight:500;color:var(--ink)}
.ctrl output{font-family:var(--f-mono);color:var(--accent)}
.toggles{display:flex;gap:6px;flex-wrap:wrap;padding:0 16px 16px}
.tg{font-family:var(--f-mono);font-size:.74rem;padding:6px 12px;border-radius:999px;border:1px solid var(--line);color:var(--muted)}
.tg[aria-pressed="true"]{color:var(--c);border-color:var(--c);background:color-mix(in srgb,var(--c) 10%,transparent)}
.reads{display:grid;grid-template-columns:repeat(4,minmax(0,1fr));border-top:1px solid var(--line)}
.reads div{padding:12px 16px;display:grid;gap:0}
.reads div+div{border-left:1px solid var(--line)}
.reads span{font-size:.72rem;color:var(--muted)}
.reads b{font-family:var(--f-mono);font-weight:500;font-size:.98rem;color:var(--ink);font-variant-numeric:tabular-nums}
@media (max-width:620px){.fig-ctrl{grid-template-columns:1fr 1fr}.fig-ctrl .btn{grid-column:span 2}.reads{grid-template-columns:repeat(2,minmax(0,1fr))}.reads div:nth-child(3){border-left:0}.reads div:nth-child(n+3){border-top:1px solid var(--line)}}

.steps{border:1px solid var(--line);border-radius:18px;overflow:hidden}
.steps-head{display:flex;justify-content:space-between;align-items:center;gap:12px;padding:14px 18px;background:var(--tint);border-bottom:1px solid var(--line);flex-wrap:wrap}
.steps-head b{color:var(--ink);font-weight:600}
.steps ol{list-style:none;margin:0;padding:0}
.steps .step{display:grid;grid-template-columns:36px minmax(0,1fr);gap:14px;padding:16px 18px;border-bottom:1px solid var(--line);margin:0}
.steps .step:last-child{border-bottom:0}
.steps .step .no{width:28px;height:28px;border-radius:50%;border:1px solid var(--accent);color:var(--accent);display:grid;place-items:center;font-family:var(--f-mono);font-size:.75rem}
.steps .step p{font-size:.97rem}
.steps .step .m{overflow-x:auto;color:var(--ink);padding-top:2px}
.steps .step.hidden{display:none}

.rw{border:1px solid var(--line);border-radius:18px;overflow:hidden;background:var(--surface)}
.rw-tabs{display:flex;border-bottom:1px solid var(--line);background:var(--tint);overflow-x:auto;scrollbar-width:thin}
.rw-tabs button{padding:13px 18px;font-weight:600;font-size:.9rem;color:var(--muted);border-bottom:2px solid transparent;white-space:nowrap;flex:none}
.rw-tabs button:hover{color:var(--ink)}
.rw-tabs button[aria-selected="true"]{color:var(--accent);border-bottom-color:var(--accent);background:var(--surface)}
.rw-panel{display:grid;grid-template-columns:130px minmax(0,1fr);gap:20px;padding:20px;align-items:center}
.rw-panel svg{width:100%;height:auto}
.rw-panel p{font-size:.97rem}
.rw-panel .f{font-family:var(--f-mono);font-size:.85rem;color:var(--accent);margin-top:8px;display:block}
@media (max-width:520px){.rw-panel{grid-template-columns:1fr}.rw-panel svg{max-width:140px}}

.video{display:grid;grid-template-columns:220px minmax(0,1fr);border:1px solid var(--line);border-radius:18px;overflow:hidden;background:var(--surface);transition:border-color .2s;color:inherit}
.video:hover{border-color:var(--accent)}
.thumb{background:var(--band);position:relative;aspect-ratio:16/10;display:grid;place-items:center;max-width:100%;overflow:hidden}
.thumb img{position:absolute;inset:0;width:100%;height:100%;object-fit:cover;opacity:.85}
.thumb svg.wave{position:absolute;inset:0;width:100%;height:100%}
.play{width:54px;height:54px;border-radius:50%;background:#fff;display:grid;place-items:center;position:relative;box-shadow:0 8px 20px rgba(0,0,0,.3)}
.thumb .dur{position:absolute;right:8px;bottom:8px;background:rgba(0,0,0,.6);color:#fff;font-family:var(--f-mono);font-size:.7rem;padding:2px 6px;border-radius:4px}
.video .vb{padding:18px 20px;display:grid;gap:6px;align-content:center;min-width:0}
.video .vb b{color:var(--ink);font-size:1.05rem}
.video .vb span:not(.eyebrow){font-size:.9rem;color:var(--muted)}
@media (max-width:560px){.video{grid-template-columns:1fr}}

.pdf{border:1px solid var(--line);border-radius:20px;background:var(--tint);padding:clamp(18px,3vw,26px);display:grid;grid-template-columns:200px minmax(0,1fr);gap:clamp(18px,3vw,28px);align-items:start}
.flip{display:grid;gap:10px;justify-items:center}
.pdf .page{width:100%;max-width:180px;aspect-ratio:1/1.414;background:#fff;border-radius:6px;box-shadow:0 1px 0 var(--line),0 14px 26px -14px rgba(20,33,61,.45);padding:14px 12px;display:flex;flex-direction:column;gap:6px;position:relative;overflow:hidden;color:#14213D;transition:transform .35s}
.pdf .page::after{content:"";position:absolute;right:0;top:0;border-width:0 18px 18px 0;border-style:solid;border-color:var(--tint) var(--tint) #E6EAF0 #E6EAF0}
.pdf .page h5{margin:0;font-family:var(--f-display);font-weight:500;font-size:.82rem;line-height:1.2;color:#14213D;display:-webkit-box;-webkit-line-clamp:3;-webkit-box-orient:vertical;overflow:hidden}
.pdf .page .ln{height:4px;border-radius:3px;background:#E6EAF0;flex:none}
.pdf .page .hi{height:9px;border-radius:2px;background:#FDF3E2;font-family:var(--f-mono);font-size:6.5px;color:#14213D;padding-left:3px;line-height:9px;flex:none;width:70%}
.pdf .page .brand{position:absolute;bottom:8px;left:12px;right:12px;display:flex;justify-content:space-between;font-family:var(--f-mono);font-size:6px;color:#667189}
.pd-page-sub{font-family:var(--f-mono);font-size:6.5px;color:#2453D6;text-transform:uppercase;letter-spacing:.06em;white-space:nowrap;overflow:hidden;text-overflow:ellipsis}
.pd-stack-pages{position:relative;width:100%;max-width:180px;aspect-ratio:1/1.414}
.pdf .pd-stack-pages .page{position:absolute;inset:0;max-width:none}
.pd-stack-pages .pd-pdfback-2{transform:rotate(-6deg) translate(-6px,6px);opacity:.7}
.pd-stack-pages .pd-pdfback-1{transform:rotate(3.5deg) translate(5px,3px);opacity:.88}
.pd-stack-pages .pd-pdfback{background:#fff}
.pd-stack-pages .pd-pdfback::after{display:none}
.pd-pdf:hover .pd-stack-pages .page:last-child{transform:translateY(-4px) rotate(-1deg)}
.pd-stack-note{font-family:var(--f-mono);font-size:.75rem;color:var(--muted);margin-top:8px}
.flip-ctl{display:flex;align-items:center;gap:10px;font-family:var(--f-mono);font-size:.75rem;color:var(--muted)}
.flip-ctl button{width:30px;height:30px;border-radius:50%;border:1px solid var(--line);background:var(--surface);display:grid;place-items:center;color:var(--ink)}
.flip-ctl button:hover{border-color:var(--accent)}
.pdf-body{display:grid;gap:12px;min-width:0}
.pdf-body h3{font-size:1.45rem;margin:0}
.pdf-body ul{margin:0;padding-left:1.1em;font-size:.93rem;display:grid;gap:3px}
.pdf-facts{display:flex;flex-wrap:wrap;gap:6px}
.pdf-actions{display:flex;flex-wrap:wrap;gap:10px;align-items:center}
.share{display:flex;gap:8px;align-items:center;flex-wrap:wrap;font-size:.82rem;color:var(--muted);padding-top:12px;border-top:1px dashed var(--line)}
.share a,.share button{display:inline-flex;align-items:center;gap:6px;padding:6px 11px;border-radius:999px;border:1px solid var(--line);background:var(--surface);color:var(--ink)!important;font-size:.8rem;font-weight:500;text-decoration:none!important;line-height:1.4}
.share a:hover,.share button:hover{border-color:var(--accent)}
.gate{display:grid;gap:8px;background:var(--surface);border:1px solid var(--line);border-radius:12px;padding:14px}
.gate label{font-size:.8rem;font-weight:600;color:var(--ink)}
.gate .row{display:flex;gap:8px;flex-wrap:wrap}
.gate input{flex:1;min-width:180px;font:inherit;padding:10px 12px;border-radius:10px;border:1px solid var(--line);background:var(--paper);color:var(--ink)}
.gate .ok{color:var(--good);font-weight:600;font-size:.9rem}
.nosign{display:inline-flex;align-items:center;gap:6px;font-size:.8rem;color:var(--good);font-weight:600}
.dl-btn.busy{pointer-events:none;opacity:.85}
.dl-btn.busy svg{animation:dlb .8s ease-in-out infinite}
@keyframes dlb{50%{transform:translateY(3px)}}
@media (max-width:620px){.pdf{grid-template-columns:1fr}.pd-stack{max-width:150px;justify-self:center;width:100%}}

.quiz{border:1px solid var(--line);border-radius:20px;overflow:hidden}
.quiz-head{display:flex;justify-content:space-between;align-items:center;gap:10px;padding:14px 18px;background:var(--tint);border-bottom:1px solid var(--line);flex-wrap:wrap}
.quiz-head b{color:var(--ink)}
.quiz .score{font-family:var(--f-mono);font-size:.8rem;color:var(--muted)}
.q{padding:18px;border-bottom:1px solid var(--line);display:grid;gap:12px}
.q:last-child{border-bottom:0}
.q p.qt{color:var(--ink);font-weight:500}
.q .opts{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:8px}
.q .o{text-align:left;padding:10px 14px;border-radius:10px;border:1px solid var(--line);background:var(--surface);font-size:.93rem;transition:border-color .15s}
.q .o:hover:not([disabled]){border-color:var(--accent)}
.q .o[disabled]{cursor:default}
.q .o.right{border-color:var(--good);background:var(--good-soft);color:var(--good);font-weight:600}
.q .o.wrong{border-color:var(--bad);background:var(--bad-soft);color:var(--bad)}
.q .why{font-size:.9rem;color:var(--ink-2);background:var(--tint);border-radius:10px;padding:10px 14px}
@media (max-width:520px){.q .opts{grid-template-columns:1fr}}

.cards{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:12px}
.fc{perspective:900px;min-height:170px}
.fc button{width:100%;height:100%;min-height:170px;position:relative;transform-style:preserve-3d;transition:transform .5s;text-align:left}
.fc button.on{transform:rotateY(180deg)}
.fc .face{position:absolute;inset:0;border-radius:16px;padding:18px;display:flex;flex-direction:column;justify-content:space-between;backface-visibility:hidden;-webkit-backface-visibility:hidden;border:1px solid var(--line)}
.fc .front{background:var(--surface)}
.fc .front b{font-family:var(--f-display);font-size:1.15rem;font-weight:400;color:var(--ink);line-height:1.3}
.fc .back{background:var(--accent);color:var(--accent-ink);transform:rotateY(180deg);border-color:var(--accent)}
.fc .back b{font-size:.98rem;line-height:1.45}
.fc small{font-family:var(--f-mono);font-size:.68rem;opacity:.7;letter-spacing:.06em}
@media (max-width:700px){.cards{grid-template-columns:1fr}.fc,.fc button{min-height:130px}}

.takeaways{border-top:2px solid var(--ink);padding-top:18px;display:grid;gap:12px}
.takeaways ol{margin:0;padding-left:1.3em;display:grid;gap:8px}
.takeaways li::marker{font-family:var(--f-mono);color:var(--accent);font-size:.85em}
.helpful{display:flex;align-items:center;justify-content:space-between;gap:12px;flex-wrap:wrap;padding:16px 18px;border:1px solid var(--line);border-radius:14px;font-size:.93rem}
.helpful div{display:flex;gap:8px}
.helpful button{padding:7px 14px;border-radius:999px;border:1px solid var(--line);font-size:.85rem;font-weight:500}
.helpful button:hover{border-color:var(--accent);color:var(--accent)}

.pn{display:grid;grid-template-columns:1fr 1fr;gap:12px}
.pn a{border:1px solid var(--line);border-radius:14px;padding:16px 18px;display:grid;gap:4px;transition:border-color .2s;min-width:0}
.pn a:hover{border-color:var(--accent)}
.pn a.pn-next{text-align:right}
.pn small{font-family:var(--f-mono);font-size:.7rem;color:var(--muted);letter-spacing:.06em;text-transform:uppercase}
.pn b{color:var(--ink);font-weight:600;font-size:.97rem;line-height:1.35}
@media (max-width:520px){.pn{grid-template-columns:1fr}.pn a.pn-next{text-align:left}.pn>span:empty{display:none}}

.authorbox{display:grid;grid-template-columns:64px minmax(0,1fr);gap:16px;padding:20px;border-radius:16px;background:var(--tint);border:1px solid var(--line)}
.authorbox .avatar{width:64px;height:64px;font-size:1.6rem}
.authorbox b{color:var(--ink)}
.authorbox p{font-size:.93rem}
.pd-ab-body{display:grid;gap:4px}
.pd-ab-years{font-family:var(--f-mono);font-size:.72rem;color:var(--muted)}

.rcard{border:1px solid var(--line);border-radius:16px;background:var(--surface);padding:18px;display:grid;gap:12px;min-width:0}
.rcard h4{font-size:1.15rem}
.rcard .eyebrow{font-size:.66rem}
.rcard .share{border-top:0;padding-top:0}
.rpdf{background:var(--accent-soft);border-color:color-mix(in srgb,var(--accent) 25%,var(--line))}
.rpdf .row{display:flex;gap:12px;align-items:center}
.rpdf .ic{width:40px;height:50px;border-radius:5px;background:#fff;border:1px solid var(--line);display:grid;place-items:center;font-family:var(--f-mono);font-size:.6rem;color:#C2413A;font-weight:600;flex:none}
.rpdf p{font-size:.85rem;color:var(--muted)}
.fl{display:grid;gap:0}
.fl div{display:flex;justify-content:space-between;gap:10px;padding:9px 0;border-bottom:1px dashed var(--line);font-size:.85rem;align-items:center}
.fl div:last-child{border-bottom:0}
.fl span{color:var(--muted)}
.fl code{font-family:var(--f-mono);font-size:.8rem;color:var(--ink);white-space:nowrap}
.path{list-style:none;margin:0;padding:0;display:grid;gap:2px}
.path a{display:flex;align-items:flex-start;gap:10px;padding:8px 10px;border-radius:10px;font-size:.88rem;line-height:1.35}
.path a span{min-width:0;flex:1;display:grid;gap:2px}
.path a:hover{background:var(--tint)}
.path i{width:8px;height:8px;border-radius:50%;background:var(--c);flex:none;margin-top:.4em}
.path .here{background:var(--tint);color:var(--ink);font-weight:600}
.path em{font-style:normal;font-family:var(--f-mono);font-size:.64rem;letter-spacing:.04em;color:var(--muted);font-weight:400}
.path .here em{color:var(--type,var(--accent))}

/* from the book review preview */
.disc{font-size:.72rem;color:var(--muted);line-height:1.4}
.fit-q{padding:16px 20px;border-bottom:1px solid var(--line);display:grid;gap:10px}
.fit-q b{color:var(--ink);font-size:.98rem}
.pills{display:flex;flex-wrap:wrap;gap:6px}
.pills button{padding:8px 14px;border-radius:999px;border:1px solid var(--line);font-size:.88rem;font-weight:500;background:var(--surface)}
.pills button:hover{border-color:var(--accent)}
.pills button[aria-pressed="true"]{border-color:var(--accent);background:var(--accent-soft);color:var(--accent);font-weight:600}
.faq{border:1px solid var(--line);border-radius:16px;overflow:hidden}
.faq details{border-bottom:1px solid var(--line)}
.faq details:last-child{border-bottom:0}
.faq summary{padding:14px 18px;cursor:pointer;font-weight:600;color:var(--ink);list-style:none;display:flex;justify-content:space-between;gap:12px}
.faq summary::-webkit-details-marker{display:none}
.faq summary::after{content:"+";font-family:var(--f-mono);color:var(--accent);font-size:1.1rem;line-height:1}
.faq details[open] summary::after{content:"−"}
.faq details p{padding:0 18px 16px;font-size:.95rem}

/* toast */
.pd-toast{position:fixed;left:50%;bottom:calc(24px + env(safe-area-inset-bottom,0px));transform:translate(-50%,20px);opacity:0;pointer-events:none;background:var(--ink);color:var(--paper);padding:12px 18px;border-radius:12px;font-size:.88rem;max-width:min(520px,calc(100vw - 32px));box-shadow:0 12px 30px -10px rgba(0,0,0,.4);transition:opacity .25s,transform .25s;z-index:1000;display:flex;gap:10px;align-items:flex-start;line-height:1.45}
.pd-toast.show{opacity:1;transform:translate(-50%,0)}
.pd-toast svg{flex:none;margin-top:2px}
.pd-toast b{color:inherit}

/* 6. Pattern blocks (as WordPress outputs them) ---------------------------------- */
.pd-content .pd-tldr{border:1px solid color-mix(in srgb,var(--accent) 28%,var(--line));background:var(--accent-soft);border-radius:16px;padding:22px 24px;display:grid;gap:10px}
.pd-content .pd-tldr > *{margin:0;max-width:none}
.pd-content .pd-tldr p{color:var(--ink);font-size:1.05rem}
.pd-content .pd-tldr .pd-eyebrow,.pd-eyebrow{font-family:var(--f-mono);font-size:.72rem!important;letter-spacing:.12em;text-transform:uppercase;color:var(--accent)!important;line-height:1.5}
.pd-content .pd-key,.pd-content .pd-warn{border-radius:14px;padding:18px 20px 18px 22px;display:grid;gap:6px;border:1px solid var(--line);background:var(--tint)}
.pd-content .pd-key > *,.pd-content .pd-warn > *{margin:0;max-width:none}
.pd-content .pd-warn{background:var(--signal-soft);border-color:color-mix(in srgb,var(--signal) 35%,transparent)}
.pd-content .pd-label{font-family:var(--f-mono);font-size:.72rem;font-weight:700;letter-spacing:.1em;text-transform:uppercase;line-height:1.5;color:var(--muted)}
.pd-content .pd-key .pd-label{color:var(--accent)}
.pd-content .pd-warn .pd-label{color:var(--signal)}
.pd-content .pd-formula{background:var(--tint);border:1px solid var(--line);border-radius:14px;padding:18px 20px;overflow-x:auto;text-align:center;color:var(--ink);display:grid;gap:4px}
.pd-content .pd-formula > *{margin:0;max-width:none}
.pd-content .pd-formula .pd-label{text-align:left;font-weight:400;letter-spacing:.04em;text-transform:none;font-size:.7rem}
.pd-content .pd-symbols{margin-inline:0;overflow-x:auto;border:1px solid var(--line);border-radius:14px}
.pd-content .pd-symbols table{width:100%;border-collapse:collapse;font-size:.95rem;table-layout:auto;margin:0;border:0}
.pd-content .pd-symbols th,.pd-content .pd-symbols td{padding:11px 16px;text-align:left;border:0;border-bottom:1px solid var(--line)}
.pd-content .pd-symbols tr:last-child td{border-bottom:0}
.pd-content .pd-symbols th,.pd-content .pd-symbols thead td{font-family:var(--f-mono);font-size:.7rem;letter-spacing:.08em;text-transform:uppercase;color:var(--muted);font-weight:500;background:var(--tint)}
.pd-content .pd-symbols thead{border:0}
.pd-content .pd-symbols td:first-child{color:var(--ink);white-space:nowrap}
.pd-content .pd-symbols td:last-child{font-family:var(--f-mono);font-size:.85rem;white-space:nowrap}
.pd-content .pd-symbols figcaption{padding:8px 16px;margin:0}
.pd-content ol.pd-takeaways{border-top:2px solid var(--ink);padding:18px 0 0 1.6em;display:grid;gap:8px;list-style:decimal}
.pd-content ol.pd-takeaways::before{content:"Key takeaways";display:block;margin-left:-1.6em;margin-bottom:4px;font-family:var(--f-mono);font-size:.72rem;letter-spacing:.12em;text-transform:uppercase;color:var(--muted)}
.pd-content ol.pd-takeaways li{margin:0}
.pd-content ol.pd-takeaways li::marker{font-family:var(--f-mono);color:var(--accent);font-size:.85em}
.pd-content .pd-faq{border:1px solid var(--line);border-radius:16px;overflow:hidden;display:block;background:var(--surface)}
.pd-content .pd-faq > *{margin:0;max-width:none}
.pd-content .pd-faq details,.pd-content .pd-faq details.wp-block-details{border:0;border-bottom:1px solid var(--line);border-radius:0;padding:0;margin:0}
.pd-content .pd-faq details:last-child{border-bottom:0}
.pd-content .pd-faq summary{padding:14px 18px;cursor:pointer;font-weight:600;color:var(--ink);list-style:none;display:flex;justify-content:space-between;gap:12px;line-height:1.45}
.pd-content .pd-faq summary::-webkit-details-marker{display:none}
.pd-content .pd-faq summary::after{content:"+";font-family:var(--f-mono);color:var(--accent);font-size:1.1rem;line-height:1.3;flex:none}
.pd-content .pd-faq details[open] summary::after{content:"−"}
.pd-content .pd-faq details > :not(summary){padding:0 18px;margin:0 0 .8em;font-size:.95rem}
.pd-content .pd-faq details > :last-child{padding-bottom:6px}
.pd-content .pd-faq summary:hover{background:var(--tint)}
/* tabs pattern before JS: heading + text blocks (selectors include .wp-block-group to win over other .pd-tabs rules) */
.pd-content .wp-block-group.pd-tabs{display:block;gap:0;flex-wrap:nowrap;border-top:0;padding-top:0}
.pd-content .wp-block-group.pd-tabs:not(.is-tabbed){border-left:3px solid var(--line);padding-left:18px}
.pd-content .pd-tabs:not(.is-tabbed) > *{margin:0;max-width:none}
.pd-content .pd-tabs:not(.is-tabbed) > * + *{margin-top:.6em}
.pd-content .pd-tabs:not(.is-tabbed) h3{font-size:1.12rem;margin-top:1.2em}
.pd-content .pd-tabs:not(.is-tabbed) h3:first-of-type{margin-top:0}
.pd-content .wp-block-group.pd-tabs.is-tabbed{padding:0;border:1px solid var(--line);border-radius:18px;overflow:hidden;background:var(--surface)}
.pd-content .pd-tabs.is-tabbed > .rw-tabs{margin:0}
.pd-tab-panel{padding:20px;display:grid;gap:10px}
.pd-tab-panel > *{margin:0!important;max-width:none}
.pd-tab-panel p{font-size:.97rem}
.pd-content .pd-tab-formula{font-family:var(--f-mono);font-size:.88rem;color:var(--accent)}
.pd-content .pd-video{margin-top:1.4em}

/* block styles */
.pd-content p.is-style-pd-lead{font-size:1.22rem;line-height:1.6;color:var(--ink)}
.pd-content .is-style-pd-pull{margin:1.8em 0;padding:6px 0 6px 26px;border-left:3px solid var(--type,var(--accent));font-family:var(--f-display);font-style:italic;font-size:1.6rem;line-height:1.3;color:var(--ink);background:none}
.pd-content .is-style-pd-pull p{font-size:inherit}
.pd-content .is-style-pd-pull cite{display:block;margin-top:10px;font-family:var(--f-mono);font-style:normal;font-size:.7rem;letter-spacing:.1em;text-transform:uppercase;color:var(--muted)}
.pd-content ul.is-style-pd-check{list-style:none;padding-left:0}
.pd-content ul.is-style-pd-check li{position:relative;padding-left:28px}
.pd-content ul.is-style-pd-check li::before{content:"";position:absolute;left:2px;top:.45em;width:14px;height:8px;border-left:2px solid var(--good);border-bottom:2px solid var(--good);transform:rotate(-45deg)}

/* 7. WordPress core blocks & classes --------------------------------------------- */
.alignleft{float:left;margin:.3em 1.4em 1em 0;max-width:50%}
.alignright{float:right;margin:.3em 0 1em 1.4em;max-width:50%}
.aligncenter{margin-inline:auto;display:block;text-align:center}
.pd-content .alignwide,.pd-content .alignfull{max-width:none}
.pd-page .pd-content .alignwide{margin-inline:calc(50% - min(500px,50vw - var(--gut)));max-width:min(1000px,100vw - 2*var(--gut))}
.pd-page .pd-content .alignfull{margin-inline:calc(50% - 50vw);max-width:100vw;width:100vw}
.pd-content figure{margin-inline:0}
.wp-caption,.wp-block-image{max-width:100%}
.wp-block-image img{border-radius:12px;display:block}
.wp-block-image.is-style-rounded img{border-radius:999px}
.wp-element-caption,.wp-caption-text,.wp-block-image figcaption,.wp-block-embed figcaption,.gallery-caption{font-size:.84rem;color:var(--muted);margin-top:8px;text-align:center;line-height:1.5}
.pd-content blockquote,.wp-block-quote{margin:1.6em 0;padding:4px 0 4px 22px;border-left:3px solid var(--accent);font-family:var(--f-display);font-size:1.25rem;line-height:1.5;color:var(--ink)}
.wp-block-quote cite,.pd-content blockquote cite{display:block;margin-top:8px;font-family:var(--f-mono);font-style:normal;font-size:.72rem;letter-spacing:.08em;text-transform:uppercase;color:var(--muted)}
.wp-block-pullquote{border-block:2px solid var(--ink);padding:24px 0;text-align:center;font-family:var(--f-display);font-size:1.5rem;color:var(--ink)}
.wp-block-pullquote blockquote{border:0;padding:0;margin:0}
.pd-content .wp-block-table{overflow-x:auto;margin-inline:0}
.pd-content .wp-block-table table{width:100%;border-collapse:collapse;font-size:.95rem}
.pd-content .wp-block-table:not(.pd-symbols) th,.pd-content .wp-block-table:not(.pd-symbols) td{border:1px solid var(--line);padding:10px 14px;text-align:left;vertical-align:top}
.pd-content .wp-block-table:not(.pd-symbols) thead{border-bottom:2px solid var(--line)}
.pd-content .wp-block-table:not(.pd-symbols) th{background:var(--tint);color:var(--ink);font-weight:600}
.pd-content .wp-block-table.is-style-stripes tbody tr:nth-child(odd){background:var(--tint)}
.pd-content .wp-block-table.is-style-stripes{border-bottom:0}
.wp-block-code{font-family:var(--f-mono)}
.wp-block-separator{border:0;border-top:1px solid var(--line);margin:2.4em auto;opacity:1}
.wp-block-separator.is-style-dots{border:0;text-align:center;color:var(--muted)}
.wp-block-separator.is-style-dots::before{content:"· · ·";letter-spacing:1em}
.wp-block-button__link{border-radius:999px;background:var(--accent);color:var(--accent-ink);padding:12px 22px;font-weight:600;text-decoration:none}
.is-style-outline>.wp-block-button__link{background:transparent;color:var(--accent);border:1px solid currentColor}
.wp-block-columns{gap:24px}
.wp-block-embed{margin-inline:0}
.wp-block-embed iframe{border-radius:14px;max-width:100%}
.wp-block-embed-youtube .wp-block-embed__wrapper{border-radius:16px;overflow:hidden;background:var(--band)}
.wp-block-gallery,.gallery{display:flex;flex-wrap:wrap;gap:12px}
.gallery-item{margin:0;flex:1 1 160px}
.gallery-item img{border-radius:10px}
.wp-block-details{border:1px solid var(--line);border-radius:12px;padding:12px 16px}
.wp-block-details summary{cursor:pointer;font-weight:600;color:var(--ink)}
.pd-content > .wp-block-details[open] > summary{margin-bottom:.5em}
.has-text-align-center{text-align:center}
.has-text-align-right{text-align:right}
.has-small-font-size{font-size:.85rem}
.has-large-font-size{font-size:1.4rem}
.sticky .pd-card{border-color:color-mix(in srgb,var(--accent) 45%,var(--line))}
.bypostauthor > .comment-body .fn::after{content:"Teacher";margin-left:8px;font-family:var(--f-mono);font-size:.62rem;letter-spacing:.08em;text-transform:uppercase;color:var(--accent);background:var(--accent-soft);padding:2px 7px;border-radius:999px;vertical-align:middle}
.wp-block-search__input,.search-field{font:inherit}

/* 8. Archives + cards ------------------------------------------------------------ */
.pd-archive-head{border-bottom:0;padding-bottom:20px}
.pd-archive-head .dek{max-width:68ch}
.pd-archive-head .ptype{--type:var(--accent)}
.pd-has-format .pd-archive-head .ptype{--type:inherit}
.pd-filter{margin:0 0 28px;overflow-x:auto;scrollbar-width:thin;padding-bottom:4px}
.pd-filter ul{list-style:none;margin:0;padding:0;display:flex;gap:8px;flex-wrap:wrap}
.pd-fchip{display:inline-flex;align-items:center;gap:8px;padding:7px 14px;border-radius:999px;border:1px solid var(--line);background:var(--surface);font-size:.86rem;font-weight:500;color:var(--ink-2);white-space:nowrap;transition:border-color .15s,background .15s}
.pd-fchip i{width:8px;height:8px;border-radius:50%;background:var(--c,var(--accent))}
.pd-fchip:hover{border-color:var(--c,var(--accent))}
.pd-fchip.on{background:var(--ink);border-color:var(--ink);color:var(--paper)}
.pd-fchip.on i{background:var(--paper)}
.pd-listing{padding-block:28px 80px;border-top:1px solid var(--line)}
.pd-grid-cards{display:grid;grid-template-columns:repeat(auto-fill,minmax(min(100%,300px),1fr));gap:20px}
.pd-card{position:relative;background:var(--surface);border:1px solid var(--line);border-radius:var(--r);overflow:hidden;display:flex;flex-direction:column;transition:transform .25s,border-color .25s,box-shadow .25s;min-width:0;--c:var(--accent)}
.pd-card:hover{transform:translateY(-3px);border-color:color-mix(in srgb,var(--c) 45%,var(--line));box-shadow:var(--shadow)}
.pd-card:focus-within{border-color:var(--c)}
.pd-card-art{position:relative;height:150px;background-color:var(--sunk);background-image:linear-gradient(var(--grid) 1px,transparent 1px),linear-gradient(90deg,var(--grid) 1px,transparent 1px);background-size:20px 20px;border-bottom:1px solid var(--line);overflow:hidden;display:flex;align-items:flex-end;padding:16px 18px}
.pd-card-art::before{content:"";position:absolute;left:0;top:0;right:0;height:4px;background:var(--c)}
.pd-card-art img{position:absolute;inset:0;width:100%;height:100%;object-fit:cover}
.pd-card-art .pd-card-glyph{font-family:var(--f-display);font-style:italic;font-size:2.4rem;line-height:1;color:color-mix(in srgb,var(--c) 70%,var(--ink));opacity:.9;position:relative}
.pd-card-art svg{position:absolute;right:-10px;bottom:-10px;width:150px;height:110px;opacity:.5}
.pd-card-body{padding:20px 22px 22px;display:grid;gap:10px;flex:1;align-content:start}
.pd-card .ptype{font-size:.64rem;padding:4px 9px;position:relative;z-index:2}
.pd-card h2,.pd-card h3{font-size:1.32rem;line-height:1.22}
.pd-card h2 a::after,.pd-card h3 a::after{content:"";position:absolute;inset:0;z-index:1}
.pd-card h2 a:hover,.pd-card h3 a:hover{color:var(--accent)}
.pd-card-ex{color:var(--muted);font-size:.93rem;line-height:1.6}
.pd-card-meta{display:flex;flex-wrap:wrap;gap:8px 14px;align-items:center;margin-top:6px;padding-top:12px;border-top:1px dashed var(--line);font-family:var(--f-mono);font-size:.72rem;color:var(--muted)}
.pd-card-meta .pd-pdf-badge{color:#C2413A;border:1px solid color-mix(in srgb,#C2413A 35%,transparent);border-radius:4px;padding:1px 6px;font-weight:600}
:root[data-theme="dark"] .pd-card-meta .pd-pdf-badge{color:var(--bad)}
.pd-card-meta .pd-chapter{color:var(--ink-2)}
.pd-empty{border:1px dashed var(--line);border-radius:16px;padding:40px 24px;text-align:center;display:grid;gap:14px;justify-items:center;color:var(--muted)}
.pd-empty h2{font-size:1.6rem}
.navigation.pagination{margin-top:44px}
.nav-links{display:flex;flex-wrap:wrap;gap:6px;justify-content:center;align-items:center}
.page-numbers{display:inline-grid;place-items:center;min-width:42px;height:42px;padding:0 12px;border-radius:999px;border:1px solid var(--line);background:var(--surface);font-weight:600;font-size:.9rem;color:var(--ink-2)}
a.page-numbers:hover{border-color:var(--accent);color:var(--accent)}
.page-numbers.current{background:var(--ink);border-color:var(--ink);color:var(--paper)}
.page-numbers.dots{border:0;background:none}
.pd-subcats{display:flex;flex-wrap:wrap;gap:8px;margin-top:4px}

/* 9. Search, 404, comments, pages ------------------------------------------------- */
.pd-search{display:flex;gap:8px;max-width:560px;width:100%}
.pd-search label{flex:1;min-width:0;position:relative}
.pd-search .search-field{width:100%;padding:12px 16px 12px 42px;border-radius:999px;border:1px solid var(--line);background:var(--surface);color:var(--ink);font-size:1rem;-webkit-appearance:none;appearance:none}
.pd-search .search-field:focus{outline:2px solid var(--accent);outline-offset:0;border-color:transparent}
.pd-search .pd-search-ic{position:absolute;left:15px;top:50%;transform:translateY(-50%);color:var(--muted);pointer-events:none;display:flex}
.pd-search .search-submit{flex:none}
.pd-search-head .pd-search{margin-top:8px}
.pd-404{padding-block:clamp(48px,8vw,96px);display:grid;grid-template-columns:minmax(0,1.1fr) minmax(0,.9fr);gap:clamp(28px,5vw,64px);align-items:center}
.pd-404 h1{font-size:clamp(2.2rem,5vw,3.6rem);line-height:1.05}
.pd-404 .copy{display:grid;gap:20px}
.pd-404-fig{margin:0}
.pd-404-fig .big{font-family:var(--f-display);font-size:clamp(5rem,14vw,9rem);line-height:1;color:var(--accent);font-style:italic;text-align:center;padding:24px 0 8px}
.pd-404-fig svg{display:block;width:100%;height:120px}
.pd-404 .pd-formats{display:flex;flex-wrap:wrap;gap:8px}
@media (max-width:860px){.pd-404{grid-template-columns:1fr}}

.pd-comments{display:grid;gap:24px;margin-top:8px;padding-top:32px;border-top:1px solid var(--line)}
.pd-comments-title{font-size:1.6rem}
.comment-list{list-style:none;margin:0;padding:0;display:grid;gap:14px}
.comment-list .children{list-style:none;margin:14px 0 0;padding:0 0 0 clamp(14px,4vw,32px);border-left:2px solid var(--line);display:grid;gap:14px}
.comment-body{border:1px solid var(--line);border-radius:14px;padding:16px 18px;background:var(--surface);display:grid;gap:8px}
.comment-meta{display:flex;flex-wrap:wrap;gap:6px 12px;align-items:center;font-size:.84rem;color:var(--muted)}
.comment-author{display:flex;align-items:center;gap:10px;color:var(--ink)}
.comment-author .avatar{width:32px;height:32px;border-radius:50%;font-size:.9rem}
.comment-author img.avatar{display:block}
.comment-author .says{display:none}
.comment-author .fn{font-style:normal;font-weight:600}
.comment-metadata a{color:var(--muted)}
.comment-content{font-size:.97rem}
.comment-content p+p{margin-top:.7em}
.comment-content a{color:var(--accent);text-decoration:underline}
.reply a,.comment-reply-link{font-size:.82rem;font-weight:600;color:var(--accent)}
.comment-awaiting-moderation{font-size:.84rem;color:var(--signal)}
.comment-respond{border:1px solid var(--line);border-radius:16px;padding:20px;background:var(--tint);display:grid;gap:12px}
.comment-reply-title{font-size:1.35rem}
.comment-reply-title small{font-family:var(--f-body);font-size:.82rem;margin-left:10px}
.comment-reply-title small a{color:var(--accent)}
.comment-form{display:grid;gap:12px}
.comment-form p{margin:0;display:grid;gap:6px}
.comment-form label{font-size:.84rem;font-weight:600;color:var(--ink-2)}
.comment-form input[type=text],.comment-form input[type=email],.comment-form input[type=url],.comment-form textarea{font:inherit;width:100%;padding:12px 14px;border-radius:10px;border:1px solid var(--line);background:var(--surface);color:var(--ink)}
.comment-form textarea{height:150px;resize:vertical}
.comment-form input:focus,.comment-form textarea:focus{outline:2px solid var(--accent);outline-offset:0;border-color:transparent}
.comment-form .comment-form-cookies-consent{display:flex;gap:8px;align-items:flex-start}
.comment-form .comment-form-cookies-consent label{font-weight:400}
.comment-notes,.logged-in-as{font-size:.84rem;color:var(--muted)}
.logged-in-as a{color:var(--accent)}
.form-submit .submit{justify-self:start;background:var(--accent);color:var(--accent-ink);border:0;border-radius:999px;padding:12px 22px;font:inherit;font-weight:600;cursor:pointer}
.no-comments{color:var(--muted)}
.comment-navigation .nav-links{justify-content:space-between}

.pd-page .post-head .inner{max-width:720px;margin-inline:auto}
.pd-page-body{padding-block:40px 80px}
.pd-page-body .pd-content{margin-inline:auto;max-width:720px}
.pd-page-thumb{margin:28px 0 0}
.pd-page-thumb img{border-radius:18px;display:block;width:100%}
.post-thumbnail{margin:0 0 1.4em}
.post-thumbnail img{border-radius:16px;display:block;width:100%}
.page-links{display:flex;gap:6px;align-items:center;flex-wrap:wrap;font-size:.9rem}

/* 10. Format tweaks ------------------------------------------------------------- */
.pd-format-diary .pd-content > p,.pd-format-diary .pd-content > ul li,.pd-format-diary .pd-content > ol li{font-family:var(--f-display);font-size:1.2rem;line-height:1.85}
.pd-format-diary .pd-content > p strong{font-weight:500}
.pd-format-diary .pd-content > p:first-of-type::first-letter{float:left;font-family:var(--f-display);font-size:4.6em;line-height:.82;padding:.06em .1em 0 0;color:var(--t-diary);font-weight:500}
.pd-format-diary .post-head h1{font-size:clamp(2.3rem,5vw,4rem);letter-spacing:-.02em;line-height:1.04}
.pd-format-diary .post-head .dek{font-family:var(--f-display);font-size:clamp(1.15rem,1.8vw,1.35rem);line-height:1.5;color:var(--ink-2)}
.pd-format-diary .pd-content blockquote{border-left-color:var(--t-diary);font-style:italic;font-size:1.55rem;line-height:1.3}
.pd-format-diary .pd-content h2{font-style:normal}
.pd-format-diary .ptype{border-style:dashed;transform:rotate(-1.5deg)}
.pd-format-diary .pd-content .wp-block-image figcaption{font-family:var(--f-hand);font-size:1.25rem;color:var(--muted)}

/* 11. Motion + print ----------------------------------------------------------------- */
@media (prefers-reduced-motion:reduce){*,*::before,*::after{transition:none!important;animation:none!important;scroll-behavior:auto!important}}
@media print{
  .notice,header.nav,.toc,.toc-mobile,.rail,footer.site-footer,.share,.pn,.pd-comments,.progress,.pd-toast{display:none!important}
  .post-grid{display:block}
  body{background:#fff;color:#000}
}
.pd-page-comments{max-width:720px;margin:40px auto 0}

/* ==========================================================================
   v1.1 additions: logo, colour toggle, chapter hubs, reader tools
   ========================================================================== */
.logo .pd-mark{border-radius:9px;display:block}
.pd-theme-toggle span{display:grid;place-items:center}
.pd-theme-toggle .pd-i-sun{display:none}
:root[data-theme="dark"] .pd-theme-toggle .pd-i-sun{display:grid}
:root[data-theme="dark"] .pd-theme-toggle .pd-i-moon{display:none}
@media (prefers-color-scheme:dark){
  :root:not([data-theme="light"]) .pd-theme-toggle .pd-i-sun{display:grid}
  :root:not([data-theme="light"]) .pd-theme-toggle .pd-i-moon{display:none}
}

/* chapter + class hubs */
.pd-hub-head .dek{max-width:68ch}
.pd-hub-topics{margin-top:14px;display:grid;gap:8px}
.pd-hub-topics ul{list-style:none;margin:0;padding:0;display:flex;flex-wrap:wrap;gap:8px}
.pd-hub-topics li{font-size:.86rem;border:1px solid var(--line);background:var(--surface);border-radius:999px;padding:4px 12px;color:var(--ink-2)}
.pd-hub-progress{display:flex;align-items:center;gap:12px;margin-top:16px;max-width:420px}
.pd-hub-progress[hidden]{display:none}
.pd-hub-bar{flex:1;height:8px;border-radius:99px;background:var(--line);overflow:hidden}
.pd-hub-bar i{display:block;height:100%;width:0;background:var(--good);border-radius:99px;transition:width .4s}
.pd-hub-ptext{font-family:var(--f-mono);font-size:.75rem;color:var(--muted);white-space:nowrap}
.pd-hub-soon{border:1px solid var(--signal);background:var(--signal-soft);border-radius:12px;padding:14px 18px;margin:8px 0 22px;color:var(--ink-2)}
.pd-path{list-style:none;margin:8px 0 40px;padding:0;display:grid;gap:0;counter-reset:none}
.pd-lp{display:grid;grid-template-columns:44px minmax(0,1fr);gap:16px;position:relative;padding-bottom:26px}
.pd-lp:not(:last-child)::before{content:"";position:absolute;left:21px;top:44px;bottom:0;width:2px;background:var(--line)}
.pd-lp-n{width:44px;height:44px;border-radius:50%;display:grid;place-items:center;font-weight:700;font-family:var(--f-mono);background:var(--c);color:#fff;position:relative;z-index:1}
.pd-lp.is-empty .pd-lp-n{background:var(--surface);color:var(--muted);border:2px dashed var(--line)}
.pd-lp-body{min-width:0;border:1px solid var(--line);border-radius:var(--r);background:var(--surface);padding:16px 18px;box-shadow:var(--shadow)}
.pd-lp.is-empty .pd-lp-body{box-shadow:none;background:transparent;border-style:dashed}
.pd-lp-body h2{font-family:var(--f-display);font-size:1.35rem;margin:0;line-height:1.25}
.pd-lp-help{margin:4px 0 10px;color:var(--muted);font-size:.93rem}
.pd-lp-soon{margin:0;font-family:var(--f-mono);font-size:.75rem;letter-spacing:.08em;text-transform:uppercase;color:var(--muted)}
.pd-hub-list{list-style:none;margin:0;padding:0;display:grid}
.pd-hub-row{display:flex;align-items:center;gap:8px;border-top:1px solid var(--line)}
.pd-hub-row:first-child{border-top:0}
.pd-hub-row>a{flex:1;min-width:0;display:flex;align-items:center;gap:12px;padding:11px 2px;color:var(--ink);text-decoration:none}
.pd-hub-row>a:hover .pd-hub-t{color:var(--accent);text-decoration:underline;text-underline-offset:3px}
.pd-hub-dot{width:10px;height:10px;border-radius:50%;background:var(--c,var(--accent));flex:none}
.pd-hub-t{flex:1;min-width:0;font-weight:600;line-height:1.35}
.pd-hub-m{font-family:var(--f-mono);font-size:.72rem;color:var(--muted);white-space:nowrap}
.pd-hub-m b{color:var(--bad);font-weight:600}
.pd-hub-done{display:none;width:22px;height:22px;border-radius:50%;background:var(--good);color:#fff;font-size:.75rem;place-items:center;flex:none}
.pd-hub-row.is-done .pd-hub-done{display:grid}
.pd-hub-row.is-done .pd-hub-t{color:var(--muted)}
.pd-hub-more,.pd-hub-all{margin:10px 0 40px}
.pd-hub-more h2,.pd-hub-all h2,.pd-latest-h{font-family:var(--f-display);font-size:1.5rem;margin:0 0 14px}
.pd-hub-more .pd-hub-list{border:1px solid var(--line);border-radius:var(--r);padding:4px 16px;background:var(--surface)}
.pd-chap-pn{margin:0 0 36px}
.pd-chap-grid{list-style:none;margin:0;padding:0;display:grid;grid-template-columns:repeat(auto-fill,minmax(230px,1fr));gap:12px}
.pd-chap a{display:grid;grid-template-columns:auto minmax(0,1fr);grid-template-areas:"n t" "n c";column-gap:12px;row-gap:2px;align-items:center;border:1px solid var(--line);border-radius:14px;padding:14px 16px;background:var(--surface);color:var(--ink);text-decoration:none;height:100%;transition:border-color .2s,transform .2s}
.pd-chap a:hover{border-color:var(--accent);transform:translateY(-2px)}
.pd-chap-n{grid-area:n;font-family:var(--f-mono);font-weight:700;color:var(--accent);background:var(--accent-soft);border-radius:10px;width:40px;height:40px;display:grid;place-items:center;font-size:.85rem}
.pd-chap-t{grid-area:t;font-weight:600;line-height:1.3}
.pd-chap-c{grid-area:c;font-family:var(--f-mono);font-size:.7rem;color:var(--good);letter-spacing:.04em}
.pd-chap.is-empty .pd-chap-c{color:var(--muted)}
.pd-chap.is-empty .pd-chap-n{background:var(--sunk);color:var(--muted)}
.pd-chap.is-current a{border-color:var(--accent);box-shadow:0 0 0 3px var(--accent-soft)}
.pd-class-hub{margin-top:8px}
.pd-empty-links{display:flex;flex-wrap:wrap;gap:10px;justify-content:center}
@media (max-width:600px){
  .pd-lp{grid-template-columns:34px minmax(0,1fr);gap:10px}
  .pd-lp-n{width:34px;height:34px;font-size:.85rem}
  .pd-lp:not(:last-child)::before{left:16px;top:34px}
  .pd-lp-body{padding:14px}
  .pd-hub-row>a{flex-wrap:wrap;row-gap:2px}
  .pd-hub-t{flex-basis:calc(100% - 60px)}
  .pd-hub-m{margin-left:22px}
}

/* v1.2: sections hidden from PhysicsDNA → Site Control */
.pd-hide-header_cta .nav-cta .btn,.pd-hide-header_cta .pd-mobile-menu li:has(>.btn){display:none!important}
.pd-hide-theme_toggle .pd-theme-toggle{display:none!important}
.pd-hide-footer_social .site-footer .social{display:none!important}
.pd-hide-footer_note .pd-foot-note{display:none!important}
.pd-hide-progress #pd-progress{display:none!important}
.pd-hide-toc .toc,.pd-hide-toc .toc-mobile{display:none!important}
.pd-hide-rail .rail{display:none!important}
.pd-hide-text_size .pd-fs{display:none!important}
.pd-hide-study_bar .pd-study-bar{display:none!important}
.pd-hide-author_box .authorbox{display:none!important}
.pd-hide-prev_next.single .pd-main-col>.pn{display:none!important}
.pd-hide-back_top .pd-top{display:none!important}
.pd-hide-hub_topics .pd-hub-topics{display:none!important}
.pd-hide-hub_tests .pd-lp#tests{display:none!important}
@media (min-width:1181px){
  .pd-hide-toc .post-grid{grid-template-columns:minmax(0,1fr) 290px}
  .pd-hide-rail .post-grid{grid-template-columns:200px minmax(0,1fr)}
  .pd-hide-toc.pd-hide-rail .post-grid{grid-template-columns:minmax(0,760px);justify-content:center}
}
@media (min-width:961px) and (max-width:1180px){.pd-hide-rail .post-grid{grid-template-columns:minmax(0,760px);justify-content:center}}