:root {
    --li-orange: #e56832;
    --li-orange-dark: #b8461e;
    --li-ink: #202124;
    --li-muted: #62666b;
    --li-line: #e5e4e1;
    --li-paper: #ffffff;
    --li-soft: #f7f7f5;
    --li-focus: #155eef;
    --li-radius: 18px;
    --li-radius-small: 10px;
    --li-shadow: 0 12px 32px rgba(32, 33, 36, .08);
    --li-container: 1120px;
    --li-gutter: clamp(1.1rem, 3vw, 2rem);
    --li-space-section: clamp(3.25rem, 6vw, 5.5rem);
    --li-type-display-mobile: clamp(2.05rem, 8.8vw, 2.75rem);
    --li-type-section-mobile: clamp(1.55rem, 6vw, 2.1rem);
    --li-type-subsection-mobile: 1.2rem;
    --li-type-body-mobile: 1rem;
    --li-leading-body-mobile: 1.58;
    --li-space-mobile-section: clamp(2.5rem, 8vw, 3.5rem);
    --li-font-sans: ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
    --li-font-serif: Georgia, "Times New Roman", serif;
}

*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body { margin: 0; color: var(--li-ink); background: var(--li-paper); font-family: var(--li-font-sans); font-size: 1rem; line-height: 1.65; }
a { color: inherit; text-decoration-thickness: .08em; text-underline-offset: .18em; }
a:hover { color: var(--li-orange-dark); }
img { display: block; max-width: 100%; height: auto; }
button, input, textarea, select { font: inherit; }
.container { width: min(var(--li-container), calc(100% - 2 * var(--li-gutter))); margin-inline: auto; }
.narrow-section { max-width: 900px; }
.section-shell { padding-block: var(--li-space-section); }
.section-soft { background: var(--li-soft); }
.section-accent { background: var(--li-orange); color: #fff; }
.screen-reader-text { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0, 0, 0, 0); white-space: nowrap; border: 0; }
.skip-link:focus { position: fixed; z-index: 20; inset: 1rem auto auto 1rem; width: auto; height: auto; margin: 0; padding: .6rem 1rem; background: var(--li-ink); color: #fff; clip: auto; }
:focus-visible { outline: 3px solid var(--li-focus); outline-offset: 3px; }

.site-header { border-bottom: 1px solid var(--li-line); background: rgba(255, 255, 255, .97); }
.header-inner { min-height: 72px; display: flex; align-items: center; gap: 1rem; position: relative; }
.site-brand { display: inline-flex; flex-direction: column; gap: .08rem; text-decoration: none; line-height: 1.05; flex-shrink: 0; }
.brand-wordmark { font-size: clamp(1.28rem, 2vw, 1.7rem); font-weight: 760; letter-spacing: -.055em; }
.brand-accent { color: var(--li-orange); }
.site-tagline { color: var(--li-muted); font-size: .64rem; letter-spacing: .02em; }
.menu-toggle { margin-left: auto; border: 1px solid var(--li-line); border-radius: 999px; background: #fff; color: var(--li-ink); width: 2.75rem; height: 2.75rem; cursor: pointer; }
.primary-nav { display: none; position: absolute; z-index: 10; inset: 100% 0 auto; padding: 1rem; background: #fff; border: 1px solid var(--li-line); border-top: 0; box-shadow: var(--li-shadow); }
.primary-nav.is-open { display: block; }
.menu, .menu ul { list-style: none; padding: 0; margin: 0; }
.primary-nav .menu { display: grid; gap: .25rem; }
.primary-nav a, .site-footer a { text-decoration: none; }
.primary-nav a { display: block; padding: .55rem .7rem; border-radius: var(--li-radius-small); }
.primary-nav a:hover { background: var(--li-soft); }
.header-cta { display: none; }

.button { display: inline-flex; align-items: center; justify-content: center; min-height: 2.65rem; padding: .58rem 1rem; border: 1px solid var(--li-orange); border-radius: 999px; background: var(--li-orange); color: #fff; font-weight: 700; font-size: .94rem; text-decoration: none; transition: background .18s ease, transform .18s ease; }
.button:hover { background: var(--li-orange-dark); color: #fff; transform: translateY(-1px); }
.button-small { min-height: 2.4rem; padding: .45rem .85rem; font-size: .9rem; }
.button-quiet { background: transparent; color: var(--li-orange-dark); }
.button-quiet:hover { color: #fff; }
.button-dark { border-color: var(--li-ink); background: var(--li-ink); }

.hero { padding-block: clamp(2.75rem, 5vw, 4.75rem) clamp(3.25rem, 6vw, 5.5rem); }
.hero-grid { display: grid; gap: clamp(2rem, 5vw, 3.75rem); align-items: center; }
.hero-grid-image-only { grid-template-columns: minmax(0, 1fr); }
.hero-grid-image-only .hero-media { width: min(100%, 860px); margin-inline: auto; }
.hero-copy { max-width: 32rem; }
.eyebrow { margin: 0 0 .8rem; color: var(--li-orange-dark); font-size: .76rem; font-weight: 800; letter-spacing: .12em; line-height: 1.3; text-transform: uppercase; }
.section-accent .eyebrow { color: #fff; opacity: .9; }
h1, h2, h3 { margin: 0 0 1rem; line-height: 1.12; letter-spacing: -.035em; }
h1 { font-size: clamp(2.35rem, 4.4vw, 4.15rem); max-width: 14ch; }
h2 { font-size: clamp(1.75rem, 3.2vw, 2.65rem); }
h3 { font-size: clamp(1.15rem, 1.8vw, 1.4rem); }
.hero-intro, .section-lead { max-width: 58ch; color: var(--li-muted); font-size: clamp(1rem, 1.4vw, 1.14rem); }
.hero-media { min-height: 0; overflow: hidden; border-radius: var(--li-radius); background: var(--li-soft); box-shadow: var(--li-shadow); }
.hero-media img { width: 100%; aspect-ratio: 4 / 3; object-fit: cover; }
.hero-media-placeholder { aspect-ratio: 4 / 3; display: grid; place-items: center; padding: 2rem; text-align: center; color: var(--li-muted); border: 1px dashed var(--li-orange); }

.section-heading-row { display: flex; flex-direction: column; gap: .75rem; margin-bottom: 1.5rem; }
.section-note { color: var(--li-muted); font-size: .9rem; }
.card-grid, .topic-grid { display: grid; gap: 1rem; }
.card-grid-three { grid-template-columns: 1fr; }
.feature-card, .exercise-card, .empty-state { padding: clamp(1.1rem, 2.4vw, 1.5rem); border: 1px solid var(--li-line); border-radius: var(--li-radius); background: #fff; }
.feature-card { display: flex; flex-direction: column; min-height: 12rem; }
.feature-card p, .exercise-card p { color: var(--li-muted); }
.card-title { font-size: 1.4rem; }
.card-title a { text-decoration: none; }
.card-image { order: -1; margin: -1.5rem -1.5rem 1rem; overflow: hidden; border-radius: var(--li-radius) var(--li-radius) 0 0; }
.card-image img { width: 100%; aspect-ratio: 16 / 9; object-fit: cover; }
.text-link { display: inline-flex; gap: .35rem; align-items: center; margin-top: auto; color: var(--li-orange-dark); font-weight: 750; }
.topic-grid { grid-template-columns: 1fr; }
.topic-card { display: flex; justify-content: space-between; gap: 1rem; padding: .9rem 1rem; border: 1px solid var(--li-line); border-radius: var(--li-radius-small); font-size: .98rem; text-decoration: none; }
.topic-card:hover { color: var(--li-orange-dark); border-color: var(--li-orange); }
.badge { display: inline-flex; align-items: center; width: fit-content; margin: 0 .35rem .8rem 0; padding: .25rem .55rem; border-radius: 999px; background: #fff0e9; color: var(--li-orange-dark); font-size: .72rem; font-weight: 800; letter-spacing: .04em; text-transform: uppercase; }
.badge-level { background: var(--li-ink); color: #fff; }
.badge-placeholder, .content-placeholder { color: var(--li-muted); }
.content-placeholder { display: none !important; font-style: italic; }
.empty-state { color: var(--li-muted); text-align: center; }
.split-callout { display: grid; gap: 1.25rem; align-items: center; }
.split-callout-light p { color: rgba(255, 255, 255, .88); }
.section-accent a:not(.button) { color: #fff; }

.content-area { padding-block: 2.5rem 4.5rem; }
.breadcrumbs { margin-bottom: 2.5rem; color: var(--li-muted); font-size: .9rem; }
.breadcrumbs ol { display: flex; flex-wrap: wrap; gap: .45rem; list-style: none; padding: 0; margin: 0; }
.breadcrumbs li:not(:last-child)::after { content: '/'; margin-left: .45rem; color: var(--li-line); }
.page-header, .article-header { max-width: 780px; margin-bottom: 2rem; }
.page-header h1, .article-header h1 { max-width: 20ch; }
.article-taxonomy { margin-bottom: 1rem; }
.article-meta { color: var(--li-muted); font-size: .92rem; }
.article-featured-image { margin: 0 0 2.5rem; }
.article-featured-image img { width: 100%; border-radius: var(--li-radius); }
.article-content { max-width: 740px; font-size: clamp(1.125rem, 1.15vw, 1.22rem); line-height: 1.78; }
.article-content > * + * { margin-top: 1.4em; }
.article-content h2 { margin-top: 2.7em; font-size: clamp(1.65rem, 3vw, 2.5rem); }
.article-content h3 { margin-top: 2em; font-size: clamp(1.3rem, 2.5vw, 1.8rem); }
.article-content ul, .article-content ol { padding-left: 1.3em; }
.article-content blockquote { margin-inline: 0; padding: 1rem 1.25rem; border-left: 4px solid var(--li-orange); background: var(--li-soft); }
.article-content table { display: block; max-width: 100%; overflow-x: auto; border-collapse: collapse; }
.article-content th, .article-content td { min-width: 8rem; padding: .7rem .8rem; border: 1px solid var(--li-line); text-align: left; }
.article-content th { background: var(--li-soft); }
.article-content img { border-radius: var(--li-radius-small); }
.learning-box { margin-block: 2rem; padding: 1.25rem; border: 1px solid var(--li-orange); border-radius: var(--li-radius-small); background: #fffaf7; }
.page-links { margin-top: 2rem; }
.article-exercises, .related-content { width: min(100%, 940px); margin-top: 4rem; padding-top: 2.5rem; border-top: 1px solid var(--li-line); }
.exercise-card { min-height: 11rem; }
.error-page { min-height: 55vh; }

.site-footer { padding-block: 3rem 1.25rem; border-top: 1px solid var(--li-line); background: var(--li-soft); }
.footer-grid { display: grid; gap: 2rem; }
.footer-brand { margin-bottom: 1rem; }
.footer-placeholder { color: var(--li-muted); }
.site-footer .menu { display: grid; gap: .6rem; }
.footer-bottom { padding-top: 2rem; margin-top: 2rem; border-top: 1px solid var(--li-line); color: var(--li-muted); }

@media (min-width: 48rem) {
    .header-inner { gap: 1.25rem; }
    .menu-toggle { display: none; }
    .primary-nav { display: block; position: static; padding: 0; border: 0; box-shadow: none; margin-left: auto; }
    .primary-nav .menu { display: flex; flex-wrap: wrap; justify-content: flex-end; gap: .15rem; }
    .primary-nav a { padding: .45rem .55rem; font-size: .9rem; }
    .header-cta { display: inline-flex; }
    .hero-grid { grid-template-columns: minmax(0, .95fr) minmax(22rem, 1.05fr); gap: clamp(2rem, 5vw, 3.75rem); }
    .card-grid-three { grid-template-columns: repeat(3, 1fr); }
    .topic-grid { grid-template-columns: repeat(2, 1fr); }
    .section-heading-row { flex-direction: row; justify-content: space-between; align-items: end; }
    .split-callout { grid-template-columns: 1fr 1fr; gap: clamp(2rem, 5vw, 3.75rem); }
    .footer-grid { grid-template-columns: 1fr auto; align-items: start; }
}

@media (min-width: 72rem) {
    .topic-grid { grid-template-columns: repeat(3, 1fr); }
    .article-content { margin-inline: 2.5rem 0; }
}

@media (max-width: 47.99rem) {
    .container { width: min(var(--li-container), calc(100% - 2rem)); }
    .header-inner { min-height: 64px; gap: .55rem; }
    .site-brand { min-width: 0; order: 1; }
    .brand-wordmark { font-size: clamp(1.12rem, 5vw, 1.28rem); white-space: nowrap; }
    .site-tagline { font-size: .58rem; letter-spacing: .01em; white-space: nowrap; }
    .header-cta { display: inline-flex; order: 2; margin-left: auto; min-height: 2.3rem; padding: .42rem .68rem; font-size: .78rem; white-space: nowrap; }
    .menu-toggle { order: 3; flex: 0 0 auto; width: 2.35rem; height: 2.35rem; }
    .primary-nav { order: 4; }
    .hero { padding-block: 1.5rem 2.75rem; }
    .hero-grid { gap: 1.25rem; }
    .hero-copy { max-width: none; }
    .hero h1, .page-header h1, .article-header h1 { max-width: 15ch; font-size: var(--li-type-display-mobile); }
    .hero-intro, .section-lead { font-size: var(--li-type-body-mobile); line-height: var(--li-leading-body-mobile); }
    .hero-media img, .hero-media-placeholder { aspect-ratio: 4 / 3; }
    .hero-media { border-radius: 14px; }
    .section-shell { padding-block: var(--li-space-mobile-section); }
    h2 { font-size: var(--li-type-section-mobile); }
    h3, .article-content h3 { font-size: var(--li-type-subsection-mobile); }
    .section-heading-row { margin-bottom: 1.1rem; }
    .article-content { font-size: var(--li-type-body-mobile); line-height: var(--li-leading-body-mobile); }
    .article-content h2 { font-size: var(--li-type-section-mobile); }
    .article-content table { font-size: .94rem; }
    .article-exercises, .related-content { margin-top: 3rem; padding-top: 2rem; }
}

@media (prefers-reduced-motion: reduce) {
    html { scroll-behavior: auto; }
    *, *::before, *::after { transition-duration: .01ms !important; animation-duration: .01ms !important; }
}