/*
Theme Name: Narada Mathematics Study
Description: A clear AS Level learning theme with light and dark modes.
Version: 3.3.0
Requires at least: 6.0
Requires PHP: 7.4
Text Domain: narada-mathematics-study
*/
:root{color-scheme:light;--bg:#f6f8fc;--surface:#fff;--surface-soft:#eef3fb;--text:#172339;--muted:#596b84;--navy:#112a50;--accent:#285bad;--border:#dce4f0;--shadow:0 12px 36px rgba(24,47,78,.05);--button:#173e79;--button-text:#fff;--focus:#f28c43}
:root[data-theme="dark"]{color-scheme:dark;--bg:#101827;--surface:#192437;--surface-soft:#202f47;--text:#ecf2fc;--muted:#b5c4d8;--navy:#f4f7ff;--accent:#a9c9ff;--border:#34465f;--shadow:0 12px 36px rgba(0,0,0,.18);--button:#a9c9ff;--button-text:#102038;--focus:#ffd16b}
*,*::before,*::after{box-sizing:border-box}html{scroll-behavior:smooth}body{margin:0;background:var(--bg);color:var(--text);font-family:system-ui,-apple-system,BlinkMacSystemFont,"Segoe UI",sans-serif;line-height:1.65}a{color:var(--accent)}a:hover{text-decoration-thickness:2px}button{font:inherit}button:focus-visible,a:focus-visible{outline:3px solid var(--focus);outline-offset:3px}[hidden]{display:none!important}.shell{width:min(1400px,calc(100% - 80px));margin-inline:auto}.skip-link{position:absolute;left:-9999px;z-index:99;padding:10px;background:var(--surface);color:var(--text)}.skip-link:focus{left:12px;top:12px}.site-header{background:var(--surface);border-bottom:1px solid var(--border)}.header-inner{min-height:80px;display:flex;align-items:center;gap:30px}.brand{display:inline-flex;align-items:center;gap:12px;text-decoration:none;color:var(--navy);font-size:19px;font-weight:750;letter-spacing:-.5px;white-space:nowrap}.brand-mark{font-family:Georgia,serif;display:grid;place-items:center;color:var(--button-text);background:var(--button);border-radius:8px;width:37px;height:37px;font-size:21px;line-height:1}.main-nav{display:flex;align-items:center;justify-content:center;flex:1;gap:clamp(15px,2vw,34px);flex-wrap:wrap}.main-nav a{font-size:14px;font-weight:600;text-decoration:none;color:var(--text)}.main-nav a:hover{color:var(--accent)}.theme-toggle{display:flex;align-items:center;justify-content:center;gap:8px;white-space:nowrap;background:var(--surface);color:var(--text);border:1px solid var(--border);border-radius:9px;padding:8px 12px;cursor:pointer;font-size:13px;font-weight:650}.theme-toggle:hover{background:var(--surface-soft)}.mode-icon{font-size:19px;line-height:1}.page-intro{background:var(--surface-soft);border-bottom:1px solid var(--border);padding:32px 0 38px}.breadcrumb{display:flex;gap:12px;align-items:center;font-size:13px;color:var(--muted);margin:0 0 24px}.breadcrumb a{text-decoration:none}.eyebrow,.side-label,.resource-kicker{font-weight:750;font-size:11px;letter-spacing:.14em;color:var(--accent);margin:0 0 13px}.page-intro h1{font-size:clamp(38px,4vw,58px);line-height:1.1;letter-spacing:-.035em;margin:0;color:var(--navy)}.lesson-layout{display:grid;grid-template-columns:minmax(170px,215px) minmax(0,1fr) minmax(185px,245px);gap:40px;padding-block:45px 80px;align-items:start}.chapter-nav,.lesson-aside{position:sticky;top:24px}.side-label{color:var(--muted)}.chapter-links{display:flex;flex-direction:column;gap:3px}.chapter-links a{text-decoration:none;color:var(--muted);font-weight:600;font-size:14px;padding:9px 11px;border-radius:7px}.chapter-links a:hover{background:var(--surface-soft);color:var(--accent)}.chapter-links .subheading-link{font-size:13px;font-weight:450;padding-left:22px}.lesson-article{background:var(--surface);border:1px solid var(--border);border-radius:14px;box-shadow:var(--shadow);padding:clamp(24px,3vw,48px);min-width:0}.lesson-content{font-size:16px;line-height:1.8;overflow-wrap:anywhere}.lesson-content h2,.lesson-content h3,.lesson-content h4{scroll-margin-top:30px;line-height:1.3;color:var(--navy);margin:2em 0 .6em}.lesson-content h2:first-child,.lesson-content h3:first-child{margin-top:0}.lesson-content h2{font-size:clamp(24px,2.5vw,32px);letter-spacing:-.025em;border-bottom:1px solid var(--border);padding-bottom:12px}.lesson-content h3{font-size:20px}.lesson-content p{margin:0 0 1.1em}.lesson-content a{color:var(--accent)}.lesson-content img{max-width:100%;height:auto}.lesson-content iframe,.lesson-content video{max-width:100%}.lesson-content blockquote{margin:1.5em 0;padding:14px 20px;background:var(--surface-soft);border-left:3px solid var(--accent);border-radius:0 8px 8px 0}.lesson-content blockquote p:last-child{margin-bottom:0}.lesson-content table{width:100%;border-collapse:collapse}.lesson-content td,.lesson-content th{padding:10px;border:1px solid var(--border)}.lesson-content .wp-block-file{padding:18px;border:1px solid var(--border);border-radius:10px;background:var(--surface-soft)}.lesson-content .wp-block-file .wp-block-file__button{background:var(--button)!important;color:var(--button-text)!important;border-radius:8px;padding:10px 17px;text-decoration:none;font-size:14px;font-weight:700}.lesson-content .wp-block-file .wp-block-file__button:hover{opacity:.85}.lesson-content .wp-block-file a:not(.wp-block-file__button){color:var(--accent)}.resource-card,.resources-discovered{background:var(--surface);border:1px solid var(--border);border-radius:12px;padding:20px;margin-bottom:16px}.resource-card h2{font-size:18px;line-height:1.3;color:var(--navy);margin:0 0 8px}.resource-card p{font-size:14px;color:var(--muted);margin:0 0 15px}.resource-shortcut,.resource-link{color:var(--accent);font-size:14px;font-weight:700;text-decoration:none}.resource-link{display:block;padding:10px 0}.resource-link+.resource-link{border-top:1px solid var(--border)}.general-page{padding-block:65px;min-height:60vh}.general-page h1{color:var(--navy);font-size:44px}.home-hero{padding:clamp(55px,7vw,95px) 0;border-bottom:1px solid var(--border)}.hero-grid{display:grid;grid-template-columns:1.06fr .94fr;align-items:center;gap:8%}.home-hero h1{font-size:clamp(40px,4.8vw,66px);line-height:1.08;letter-spacing:-.04em;color:var(--navy);margin:0 0 18px;max-width:650px}.hero-description{font-size:18px;color:var(--muted);max-width:520px}.hero-actions{display:flex;gap:12px;flex-wrap:wrap;margin-top:28px}.primary-button,.secondary-button{display:inline-flex;align-items:center;gap:24px;padding:12px 18px;border-radius:9px;font-weight:700;font-size:14px;text-decoration:none}.primary-button{background:var(--button);color:var(--button-text)}.secondary-button{border:1px solid var(--border);background:var(--surface);color:var(--text)}.primary-button:hover,.secondary-button:hover{opacity:.85}.hero-art{border-radius:16px;background:var(--surface);border:1px solid var(--border);padding:25px;box-shadow:var(--shadow)}.art-grid{background-color:var(--surface-soft);background-image:linear-gradient(var(--border) 1px,transparent 1px),linear-gradient(90deg,var(--border) 1px,transparent 1px);background-size:32px 32px;border-radius:10px;padding:12px}.art-grid svg{display:block;width:100%;height:auto;max-height:300px}.axis{stroke:var(--muted);stroke-width:2;fill:none}.curve{stroke:var(--accent);stroke-width:4;fill:none}.dot{fill:var(--accent)}.art-grid text{fill:var(--text);font:italic 18px Georgia,serif}.art-caption{display:block;padding-top:16px;font-size:13px;color:var(--muted)}.section{padding-block:60px}.section-heading{display:flex;justify-content:space-between;align-items:end;gap:20px;margin-bottom:26px}.section-heading h2,.statistics-card h2{color:var(--navy);font-size:clamp(26px,3vw,36px);letter-spacing:-.03em;line-height:1.2;margin:0}.section-heading>p,.statistics-card p:not(.eyebrow){color:var(--muted);margin:0}.topic-grid{display:grid;grid-template-columns:repeat(3,1fr);gap:14px}.topic-card{background:var(--surface);border:1px solid var(--border);border-radius:12px;display:flex;align-items:center;gap:15px;padding:20px;text-decoration:none;min-height:92px;color:var(--text)}a.topic-card:hover{border-color:var(--accent);box-shadow:var(--shadow)}.topic-number{font-size:12px;font-weight:750;color:var(--accent);padding:7px 8px;background:var(--surface-soft);border-radius:6px}.topic-title{font-weight:700;font-size:16px;flex:1}.topic-title small{display:block;font-weight:400;font-size:12px;color:var(--muted)}.topic-arrow{color:var(--accent);font-size:20px}.is-unavailable{color:var(--muted)}.statistics-card{display:flex;justify-content:space-between;align-items:center;gap:25px;background:var(--surface-soft);border:1px solid var(--border);border-radius:14px;padding:36px}.statistics-card h2{margin-bottom:10px}.coming{font-size:13px;color:var(--muted);white-space:nowrap}.resource-row{display:grid;grid-template-columns:repeat(3,1fr);gap:24px;border-top:1px solid var(--border)}.resource-row h3{color:var(--navy);font-size:17px;margin:0}.resource-row p{font-size:14px;color:var(--muted);margin:6px 0}.site-footer{border-top:1px solid var(--border);background:var(--surface);padding:26px 0}.footer-inner{display:flex;justify-content:space-between;gap:15px;font-size:13px;color:var(--muted)}.footer-inner strong{color:var(--navy)}
@media(max-width:1050px){.lesson-layout{grid-template-columns:190px minmax(0,1fr);gap:24px}.lesson-aside{grid-column:2;position:static;display:grid;grid-template-columns:1fr 1fr;gap:14px}.header-inner{flex-wrap:wrap;padding-block:15px}.main-nav{order:3;justify-content:flex-start;flex-basis:100%}.theme-toggle{margin-left:auto}}
@media(max-width:700px){.shell{width:min(100% - 36px,1400px)}.header-inner{gap:14px}.brand{font-size:16px}.main-nav{gap:12px 18px}.main-nav a{font-size:13px}.mode-label{font-size:12px}.hero-grid{grid-template-columns:1fr}.hero-art{margin-top:22px}.topic-grid{grid-template-columns:1fr}.section{padding-block:40px}.section-heading,.statistics-card{align-items:flex-start;flex-direction:column}.statistics-card{padding:25px}.resource-row{grid-template-columns:1fr}.lesson-layout{display:flex;flex-direction:column;padding-block:24px 50px}.chapter-nav,.lesson-aside{position:static;width:100%}.chapter-links{flex-direction:row;overflow-x:auto;padding-bottom:5px}.chapter-links a,.chapter-links .subheading-link{white-space:nowrap;padding:8px 10px}.lesson-article{width:100%}.lesson-aside{display:block}.page-intro{padding-block:24px 30px}.breadcrumb{margin-bottom:17px}.footer-inner{flex-direction:column;gap:0}}
@media(prefers-reduced-motion:reduce){html{scroll-behavior:auto}}


/* Narada Mathematics: cool, high-contrast study layout with a yellow accent. */
:root {
  --bg: #f5f7fc;
  --surface: #ffffff;
  --surface-soft: #eaf0fc;
  --text: #14284b;
  --muted: #4f6481;
  --navy: #102c55;
  --accent: #2858ad;
  --border: #d5dff0;
  --shadow: 0 12px 30px rgba(17, 42, 80, .06);
  --button: #183e78;
  --button-text: #ffffff;
  --focus: #966400;
  --highlight: #ffc83d;
  --highlight-text: #142a4b;
  --header-bg: #102d59;
  --header-text: #f6f8ff;
  --hero-bg: #f1f5fd;
  --hero-wave: #dae5fa;
  --nav-active: #dce5fb;
  --worked-bg: #eaf1ff;
  --worked-border: #b8cdf2;
  --worked-ribbon: #28549a;
  --worked-label: #ffffff;
  --practice-bg: #f8faff;
  --practice-border: #cbd8ee;
}
:root[data-theme="dark"] {
  color-scheme: dark;
  --bg: #0e1829;
  --surface: #17253a;
  --surface-soft: #20324d;
  --text: #f0f5ff;
  --muted: #bdcbe0;
  --navy: #f4f7ff;
  --accent: #b8d0ff;
  --border: #3c506d;
  --shadow: 0 12px 30px rgba(0, 0, 0, .16);
  --button: #bcd3ff;
  --button-text: #112441;
  --focus: #ffd45c;
  --highlight: #ffd04e;
  --highlight-text: #11223e;
  --header-bg: #0b1930;
  --header-text: #f6f8ff;
  --hero-bg: #172941;
  --hero-wave: #263e62;
  --nav-active: #243c60;
  --worked-bg: #1d304b;
  --worked-border: #46638c;
  --worked-ribbon: #31588e;
  --worked-label: #ffffff;
  --practice-bg: #192a42;
  --practice-border: #405674;
}
.site-header { background: var(--header-bg); border-bottom: 1px solid rgba(255,255,255,.12); }
.header-inner { min-height: 72px; }
.brand { color: var(--header-text); font-family: Georgia, 'Times New Roman', serif; font-size: 21px; letter-spacing: -.02em; }
.brand-mark { background: #dce7ff; color: #102d59; }
.main-nav a { color: var(--header-text); border-radius: 9px; padding: 8px 11px; }
.main-nav a:hover, .main-nav a.is-current { color: #ffffff; background: #315a9f; }
.theme-toggle { color: var(--header-text); background: transparent; border-color: rgba(220,232,255,.48); }
.theme-toggle:hover { color: #ffffff; background: rgba(255,255,255,.12); }
.page-intro { position: relative; overflow: hidden; background: var(--hero-bg); padding: 32px 0 40px; }
.page-intro::after { content: ''; position: absolute; z-index: 0; right: -8%; bottom: -150px; width: 65%; height: 220px; border-radius: 50% 50% 0 0; background: var(--hero-wave); opacity: .72; pointer-events: none; transform: rotate(-5deg); }
.page-intro-inner { position: relative; z-index: 1; display: flex; align-items: center; justify-content: space-between; gap: 30px; }
.page-intro-copy { max-width: 690px; }
.breadcrumb { margin-bottom: 17px; }
.page-intro h1, .home-hero h1, .section-heading h2, .statistics-card h2 { font-family: Georgia, 'Times New Roman', serif; }
.page-intro h1 { font-size: clamp(42px, 4.6vw, 66px); }
.page-intro h1::after { content: ''; display: block; width: 72px; height: 5px; border-radius: 5px; background: var(--highlight); margin-top: 15px; }
.page-intro-description { color: var(--text); margin: 16px 0 0; max-width: 620px; font-size: 16px; }
.page-intro-graph { display: block; flex: 0 0 auto; width: clamp(190px, 21vw, 270px); max-height: 170px; }
.graph-axis { fill: none; stroke: var(--muted); stroke-width: 1.5; }
.graph-curve { fill: none; stroke: var(--accent); stroke-width: 3; }
.graph-point { fill: var(--highlight); stroke: var(--navy); stroke-width: 1.5; }
.lesson-layout { grid-template-columns: minmax(190px, 240px) minmax(0, 1fr); gap: 42px; padding-block: 38px 72px; }
.chapter-nav { top: 18px; max-height: calc(100vh - 36px); overflow-y: auto; background: var(--surface); border: 1px solid var(--border); border-radius: 14px; padding: 17px 13px; }
.chapter-nav .side-label { color: var(--navy); font-family: Georgia, 'Times New Roman', serif; letter-spacing: 0; font-size: 16px; margin: 0 8px 12px; }
.chapter-links a { border-left: 4px solid transparent; color: var(--text); }
.chapter-links a:hover { background: var(--surface-soft); color: var(--navy); }
.chapter-links a.is-active { border-left-color: var(--highlight); background: var(--nav-active); color: var(--navy); }
.lesson-article { background: transparent; border: 0; border-radius: 0; box-shadow: none; padding: 0; }
.lesson-content { font-size: 16px; line-height: 1.8; }
.lesson-content h2 { font-family: Georgia, 'Times New Roman', serif; font-weight: 700; border-bottom: 1px solid var(--border); }
.lesson-content h2::after { content: ''; display: block; width: 46px; height: 4px; margin-top: 10px; border-radius: 4px; background: var(--highlight); }
.lesson-content .worked-example-card { background: var(--worked-bg) !important; border-color: var(--worked-border) !important; }
.lesson-content .worked-example-card > p:first-child { display: table; max-width: calc(100% + 40px); margin: -20px 0 18px -20px !important; padding: 9px 16px; border-radius: 9px 0 12px 0; background: var(--worked-ribbon); color: var(--worked-label); font-size: .9em; }
.lesson-content .nm-practice-set { background: var(--practice-bg) !important; border-color: var(--practice-border) !important; border-left: 4px solid var(--highlight) !important; }
.lesson-content .nm-practice-set > p:first-child { display: table; max-width: calc(100% + 40px); margin: -20px 0 14px -20px !important; padding: 9px 16px; border-radius: 7px 0 12px 0; background: var(--highlight); color: var(--highlight-text) !important; font-size: .82em !important; letter-spacing: .06em; }
.lesson-content .nm-past-paper { border-left: 4px solid var(--accent) !important; }
.lesson-content blockquote { border-left-color: var(--highlight); }
.lesson-aside { grid-column: 2; position: static; display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 16px; }
.lesson-aside > * { margin-bottom: 0; }
.topic-card:hover, a.topic-card:focus-visible { border-color: var(--accent); }
.topic-number { color: var(--highlight-text); background: var(--highlight); }
.art-grid .dot { fill: var(--highlight); }
.primary-button, .wp-block-file__button { box-shadow: 0 3px 0 rgba(0,0,0,.06); }
@media (max-width: 1050px) {
  .lesson-layout { grid-template-columns: minmax(155px, 190px) minmax(0, 1fr); gap: 24px; }
  .main-nav { order: 3; justify-content: flex-start; flex-basis: 100%; }
}
@media (max-width: 700px) {
  .brand { font-size: 17px; }
  .main-nav { gap: 4px; }
  .main-nav a { padding: 6px 8px; font-size: 12px; }
  .page-intro { padding-block: 24px 30px; }
  .page-intro-graph { display: none; }
  .page-intro::after { width: 85%; opacity: .38; }
  .page-intro-description { font-size: 15px; }
  .lesson-layout { display: flex; flex-direction: column; gap: 22px; padding-block: 24px 50px; }
  .chapter-nav { position: static; width: 100%; max-height: none; overflow: visible; padding: 12px; }
  .chapter-nav .side-label { margin: 0 6px 8px; }
  .chapter-links { flex-direction: row; overflow-x: auto; }
  .chapter-links a, .chapter-links .subheading-link { white-space: nowrap; border-left-width: 0; border-bottom: 3px solid transparent; padding: 8px 10px; }
  .chapter-links a.is-active { border-bottom-color: var(--highlight); }
  .lesson-article { width: 100%; }
  .lesson-aside { display: grid; grid-template-columns: 1fr; width: 100%; }
  .lesson-content table { display: block; overflow-x: auto; max-width: 100%; }
}
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }

/* A simple count-up timer and a connected introduction to the graph visual. */
.nm-timer-line { display:flex; align-items:center; flex-wrap:wrap; gap:9px 12px; }
.nm-timer-title { color:var(--navy); font-size:.77em; font-weight:750; letter-spacing:.06em; text-transform:uppercase; }
.nm-timer-display { color:var(--navy); font-size:1.16em; font-weight:750; font-variant-numeric:tabular-nums; min-width:4.2ch; }
.nm-timer-button { padding:7px 15px; border:1px solid var(--button); border-radius:8px; background:var(--button); color:var(--button-text); font-size:.9em; font-weight:700; cursor:pointer; }
.nm-timer-button:hover { opacity:.88; }
.nm-timer-hint { color:var(--muted); font-size:.84em; }
.lesson-content .nm-timer-reminder { margin:12px 0 0; padding:10px 12px; border-left:3px solid var(--highlight); border-radius:0 7px 7px 0; background:var(--surface); color:var(--text); font-size:.9em; line-height:1.55; }
.lesson-content .nm-timer-reminder:empty { display:none; }
.lesson-content .nm-visual-transition { margin:2rem 0 0; padding:18px 20px 14px; border:1px solid var(--border); border-bottom:0; border-radius:12px 12px 0 0; background:var(--surface-soft); }
.nm-visual-kicker { display:inline-flex; align-items:center; gap:8px; color:var(--accent); font-size:.75em; font-weight:750; letter-spacing:.08em; text-transform:uppercase; }
.nm-visual-kicker::before { content:''; width:8px; height:8px; border-radius:2px; background:var(--highlight); }
.lesson-content .nm-visual-transition p { color:var(--text); margin:5px 0 0; line-height:1.55; }
.lesson-content figure.nm-transform-visual { display:block; width:100%; margin:0 0 2rem; padding:0 20px 20px; border:1px solid var(--border); border-top:0; border-radius:0 0 12px 12px; background:var(--surface-soft); }
.lesson-content figure.nm-transform-visual img { display:block; max-width:100%; height:auto; margin-inline:auto; border-radius:7px; }
@media (max-width:700px) {
  .lesson-content .nm-visual-transition { padding:16px 14px 12px; }
  .lesson-content figure.nm-transform-visual { padding:0 14px 14px; }
}

/* A comfortable reading face paired with traditional mathematics fonts. */
@font-face { font-family:'Narada Sans'; src:url('assets/fonts/NotoSans-Regular.woff') format('woff'); font-style:normal; font-weight:400; font-display:swap; }
@font-face { font-family:'Narada Sans'; src:url('assets/fonts/NotoSans-Bold.woff') format('woff'); font-style:normal; font-weight:700; font-display:swap; }
@font-face { font-family:'Narada Math Text'; src:url('assets/fonts/LMRoman-Regular.woff') format('woff'); font-style:normal; font-weight:400; font-display:swap; }
@font-face { font-family:'Narada Math Text'; src:url('assets/fonts/LMRoman-Italic.woff') format('woff'); font-style:italic; font-weight:400; font-display:swap; }
@font-face { font-family:'Narada Math Text'; src:url('assets/fonts/LMRoman-Bold.woff') format('woff'); font-style:normal; font-weight:700; font-display:swap; }
@font-face { font-family:'Narada Math Text'; src:url('assets/fonts/LMRoman-BoldItalic.woff') format('woff'); font-style:italic; font-weight:700; font-display:swap; }
@font-face { font-family:'Narada Math'; src:url('assets/fonts/LMMath-Regular.woff') format('woff'); font-style:normal; font-weight:400; font-display:swap; }
body { font-family:'Narada Sans', 'Segoe UI', system-ui, sans-serif; }
.lesson-content { font-size:16px; line-height:1.82; }
.lesson-content em, .lesson-content i { font-family:'Narada Math Text', Cambria, 'Times New Roman', serif; font-style:italic; font-size:1.06em; }
.lesson-content math { font-family:'Narada Math', 'Cambria Math', serif; }
.lesson-content .nm-formula-line { font-family:'Narada Math Text', Cambria, 'Times New Roman', serif; font-size:1.12em; line-height:1.75; }
.lesson-content .nm-formula-line em, .lesson-content .nm-formula-line i { font-size:1em; }
.lesson-content .worked-example-card > p:first-child::before {
  content:''; display:inline-block; width:1.2em; height:1.2em; margin-right:.6em; vertical-align:-.22em;
  background:center / contain no-repeat url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 24 24' fill='none' stroke='%23ffda66' stroke-width='1.8' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpath d='M9 18h6M10 21h4M8.5 14.5c-1.45-1.1-2.3-2.62-2.3-4.5a5.8 5.8 0 0 1 11.6 0c0 1.88-.85 3.4-2.3 4.5-.73.56-1 1.19-1 2h-5c0-.81-.27-1.44-1-2Z'/%3E%3Cpath d='M12 2V.9M4.4 4.5l-.8-.8M19.6 4.5l.8-.8'/%3E%3C/svg%3E");
}
.lesson-content .nm-practice-set > p:nth-child(2) { color:var(--muted); }
.lesson-content .nm-question-card { padding:clamp(16px,2.4vw,23px); border:1px solid var(--practice-border); border-radius:11px; background:var(--surface); color:var(--text); }
.nm-question-heading { display:flex; align-items:center; justify-content:space-between; gap:12px; color:var(--navy); font-size:.87em; font-weight:700; }
.nm-question-heading:focus-visible { outline:2px solid var(--focus); outline-offset:4px; border-radius:3px; }
.nm-question-step { color:var(--accent); font-size:.83em; letter-spacing:.05em; white-space:nowrap; }
.nm-question-track { height:4px; margin:10px 0 18px; border-radius:99px; background:var(--border); overflow:hidden; }
.nm-question-track > span { display:block; height:100%; background:var(--highlight); border-radius:inherit; }
.nm-question-content { font-size:1em; line-height:1.8; }
.nm-question-context { margin:0 0 15px; padding:11px 13px; border-left:3px solid var(--accent); border-radius:0 7px 7px 0; background:var(--surface-soft); font-size:.92em; }
.nm-question-context-label { display:block; margin-bottom:3px; color:var(--accent); font-size:.78em; font-weight:700; letter-spacing:.05em; text-transform:uppercase; }
.nm-answer-details { margin-top:16px; border-top:1px solid var(--border); }
.nm-answer-details summary { padding:13px 0 4px; color:var(--accent); font-size:.92em; font-weight:700; cursor:pointer; }
.nm-answer-details summary:focus-visible { outline:3px solid var(--focus); outline-offset:3px; }
.nm-answer-content { margin-top:10px; padding:14px 16px; border-radius:8px; background:var(--surface-soft); }
.lesson-content .nm-answer-content > p { margin:0 !important; }
.nm-question-nav { display:flex; flex-wrap:wrap; justify-content:space-between; gap:10px; margin-top:14px; }
.nm-question-nav button { padding:8px 13px; border:1px solid var(--border); border-radius:8px; background:var(--surface); color:var(--navy); font-size:.88em; font-weight:700; cursor:pointer; }
.nm-question-nav .nm-question-next { margin-left:auto; background:var(--button); border-color:var(--button); color:var(--button-text); }
.nm-question-nav button:hover { opacity:.88; }
@media(max-width:700px) { .lesson-content .nm-question-card { padding:16px; } .nm-question-nav button { min-height:42px; } }


/* Keep mathematical superscripts consistent and stacked working legible. */
.lesson-content em, .lesson-content i { font-size:1em; }
.lesson-content sup { font-family:'Narada Math Text', Cambria, 'Times New Roman', serif; font-size:.74em; font-style:normal; line-height:0; vertical-align:super; }
.lesson-content p:has(br):has(math mfrac),
.lesson-content p:has(br):has(math msqrt),
.lesson-content p:has(br):has(math mroot),
.lesson-content li:has(br):has(math mfrac),
.lesson-content li:has(br):has(math msqrt),
.lesson-content li:has(br):has(math mroot),
.lesson-content .nm-question-content:has(br):has(math mfrac),
.lesson-content .nm-question-content:has(br):has(math msqrt),
.lesson-content .nm-question-content:has(br):has(math mroot),
.lesson-content .nm-math-tall { line-height:2.45 !important; }