@import url('https://fonts.googleapis.com/css2?family=Figtree:wght@400;500;600;700;800&family=Inter:wght@400;500&display=swap');

:root{
  --paper:#fafaff;
  --paper-soft:#f3f1fb;
  --surface:#ffffff;
  --ink:#1a1530;
  --ink-2:#4a4566;
  --ink-3:#7d7895;
  --line:#e6e3f0;
  --line-soft:#f0eef7;
  --brand:#6d28d9;
  --brand-deep:#5b21b6;
  --brand-soft:#ede9fe;
  --brand-tint:#f5f3ff;
  --accent:#0891b2;
  --accent-soft:#cffafe;
  --highlight:#fbbf24;
  --highlight-soft:#fef3c7;
  --beginner:#10b981;
  --intermediate:#f59e0b;
  --advanced:#ef4444;
  --shadow-sm:0 1px 3px rgba(26,21,48,.05),0 1px 2px rgba(26,21,48,.04);
  --shadow:0 4px 12px rgba(26,21,48,.06),0 2px 4px rgba(26,21,48,.04);
  --shadow-lg:0 16px 32px rgba(109,40,217,.12);
  --radius:10px;
  --radius-lg:16px;
  --sans:'Inter',sans-serif,-apple-system,BlinkMacSystemFont,'Segoe UI',Roboto,sans-serif;
  --mono:'JetBrains Mono','SF Mono',Consolas,monospace;
}

*,*::before,*::after{box-sizing:border-box}
html{-webkit-text-size-adjust:100%;scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--ink);font-family:var(--sans);font-size:16px;line-height:1.65}

a:focus-visible,button:focus-visible,summary:focus-visible,input:focus-visible,select:focus-visible,textarea:focus-visible{outline:2px solid var(--primary);outline-offset:2px;border-radius:2px}

img,svg,video{max-width:100%;height:auto;display:block}
a{color:var(--brand);text-decoration:none;transition:color .15s ease}
a:hover{color:var(--brand-deep)}
h1,h2,h3,h4,h5,h6{font-family:var(--display);font-weight:800;line-height:1.25;letter-spacing:-0.015em;margin:0 0 .5em;color:var(--ink)}
h1{font-size:clamp(1.9rem,3.6vw,2.8rem);font-weight:800}
h2{font-size:clamp(1.4rem,2.2vw,1.8rem)}
h3{font-size:1.15rem}
h4{font-size:.95rem}
h5,h6{font-size:.78rem;font-weight:700;letter-spacing:0.06em;text-transform:uppercase;color:var(--ink-2)}
p{margin:0 0 1em}
ul,ol{margin:0;padding:0;list-style:none}
button{font-family:inherit}

.skip-main{position:absolute;left:8px;top:-100px;background:var(--brand);color:#fff;padding:8px 16px;z-index:999;border-radius:8px}
.skip-main:focus{top:8px}
.bay{max-width:1200px;margin:0 auto;padding:0 24px}

/* topnav */
.topnav{background:var(--surface);border-bottom:1px solid var(--line);position:sticky;top:0;z-index:50}
.topnav-row{display:flex;align-items:center;gap:20px;padding:14px 24px}
.bar-brand-stack{display:inline-flex;align-items:center;gap:12px;color:var(--ink);flex-shrink:0}
.bar-brand-stack:hover{color:var(--ink)}
.bar-brand-glyph{display:inline-flex;align-items:center;justify-content:center;width:38px;height:38px;background:linear-gradient(135deg,var(--brand) 0%,var(--accent) 100%);color:#fff;border-radius:10px;font-weight:800;font-size:16px;flex-shrink:0;box-shadow:var(--shadow-sm)}
.bar-brand-glyph-lg{width:54px;height:54px;font-size:22px;border-radius:14px}
.bar-brand-stack-text{display:flex;flex-direction:column;line-height:1.1}
.bar-brand-stack-name{font-weight:800;font-size:16px;color:var(--ink);letter-spacing:-0.01em}
.bar-brand-stack-strap{font-size:11px;color:var(--ink-3);font-weight:500;margin-top:2px;font-family:var(--mono);letter-spacing:0.04em}
.lessons-nav{display:flex;align-items:center;gap:2px;flex:1;overflow-x:auto;scrollbar-width:none}
.lessons-nav::-webkit-scrollbar{display:none}
.lessons-nav-item{display:inline-flex;align-items:center;gap:6px;padding:9px 14px;color:var(--ink-2);font-weight:500;font-size:14px;border-radius:8px;white-space:nowrap;transition:all .15s ease}
.lessons-nav-item:hover{color:var(--brand);background:var(--brand-tint)}.lessons-nav-item:focus-visible{outline:2px solid var(--brand);outline-offset:2px;border-radius:4px}
.lessons-nav-item.is-on{color:var(--brand);background:var(--brand-soft);font-weight:600}
.lessons-nav-icon{display:inline-block;font-size:12px}
.topnav-tools{display:flex;align-items:center;gap:10px;flex-shrink:0}
.lesson-search{display:flex;align-items:stretch;background:var(--paper-soft);border:1px solid var(--line);border-radius:10px;padding:0;overflow:hidden;transition:all .15s ease;height:38px}
.lesson-search:focus-within{border-color:var(--brand);background:#fff;box-shadow:0 0 0 3px var(--brand-soft)}
.lesson-search input{border:0;background:transparent;padding:0 14px;font-size:14px;outline:0;font-family:var(--sans);color:var(--ink);min-width:180px}
.lesson-search input::placeholder{color:var(--ink-3)}
.lesson-search button{background:var(--ink);color:#fff;border:0;width:38px;display:inline-flex;align-items:center;justify-content:center;cursor:pointer;flex-shrink:0}
.lesson-search button:hover{background:var(--brand)}
.topnav-cta{display:inline-block;background:var(--brand);color:#fff;padding:9px 16px;border-radius:8px;font-weight:600;font-size:13px;transition:all .15s ease}
.topnav-cta:hover{background:var(--brand-deep);color:#fff;transform:translateY(-1px);box-shadow:var(--shadow-sm)}
@media(max-width:980px){.lessons-nav{display:none}.lesson-search input{min-width:120px}}
@media(max-width:560px){.bar-brand-stack-strap{display:none}.topnav-cta{display:none}}

/* welcome (home hero) */
.welcome{padding:48px 0 32px;background:linear-gradient(180deg,var(--brand-tint) 0%,var(--paper) 100%);border-bottom:1px solid var(--line)}
.welcome-row{display:grid;grid-template-columns:1.6fr 1fr;gap:48px;align-items:start}
.welcome-eyebrow{display:inline-block;background:var(--brand-soft);color:var(--brand);font-weight:600;font-size:13px;padding:6px 14px;border-radius:999px;margin:0 0 18px;letter-spacing:0.01em}
.welcome-headline{font-size:clamp(2rem,4.2vw,3.4rem);font-weight:800;letter-spacing:-0.025em;line-height:1.05;margin:0 0 .4em;color:var(--ink)}
.welcome-deck{font-size:1.15rem;color:var(--ink-2);margin-bottom:1.4em;max-width:620px;line-height:1.55}
.lesson-search-big{height:54px;border-radius:14px;max-width:580px;border-width:2px}
.lesson-search-big input{font-size:16px;padding:0 20px}
.lesson-search-big button{width:auto;padding:0 24px;font-size:14px;font-weight:600;background:var(--brand)}
.lesson-search-big button:hover{background:var(--brand-deep)}
.welcome-aside-card{background:var(--surface);padding:22px 24px;border-radius:var(--radius-lg);border:1px solid var(--line);box-shadow:var(--shadow-sm)}
.welcome-aside-card h4{font-size:11px;color:var(--ink-3);text-transform:uppercase;letter-spacing:0.08em;margin:0 0 14px;font-weight:700}
.level-pick{display:flex;flex-direction:column;gap:6px}
.level-pick a{display:flex;align-items:center;gap:12px;padding:10px 14px;border-radius:8px;color:var(--ink);font-weight:500;font-size:14px;transition:all .15s ease}
.level-pick a:hover{background:var(--paper-soft);color:var(--brand)}
.level-dot{display:inline-block;width:10px;height:10px;border-radius:50%;flex-shrink:0}
.level-dot-1{background:var(--beginner);box-shadow:0 0 0 3px rgba(16,185,129,.18)}
.level-dot-2{background:var(--intermediate);box-shadow:0 0 0 3px rgba(245,158,11,.18)}
.level-dot-3{background:var(--advanced);box-shadow:0 0 0 3px rgba(239,68,68,.18)}
@media(max-width:880px){.welcome-row{grid-template-columns:1fr}}

/* track sections */
.track{padding:48px 0}
.track-head{display:flex;align-items:flex-end;justify-content:space-between;gap:24px;margin-bottom:24px;flex-wrap:wrap}
.track-head h2{margin:0;font-size:clamp(1.4rem,2.2vw,1.9rem)}
.track-eyebrow{display:inline-block;font-size:11px;font-weight:700;color:var(--brand);background:var(--brand-soft);padding:5px 11px;border-radius:999px;letter-spacing:0.06em;text-transform:uppercase;margin-bottom:8px}
.track-link{font-weight:600;font-size:14px;color:var(--brand);display:inline-flex;align-items:center;gap:4px}
.track-link:hover{color:var(--brand-deep)}

.track-grid{display:grid;grid-template-columns:repeat(auto-fill,minmax(300px,1fr));gap:18px;padding:0}
.track-grid-tight{grid-template-columns:repeat(auto-fill,minmax(260px,1fr));gap:14px}

/* lesson tile */
.lesson-tile{background:var(--surface);border-radius:var(--radius-lg);border:1px solid var(--line);overflow:hidden;display:flex;flex-direction:column;transition:all .25s ease;list-style:none}
.lesson-tile:hover{transform:translateY(-3px);box-shadow:var(--shadow-lg);border-color:var(--brand-soft)}
.lesson-tile-art{display:block;aspect-ratio:16/10;background:var(--paper-soft);position:relative;overflow:hidden}
.lesson-tile-art img{width:100%;height:100%;object-fit:cover;transition:transform .4s ease}
.lesson-tile:hover .lesson-tile-art img{transform:scale(1.05)}
.lesson-tile-badge{position:absolute;top:12px;left:12px;background:rgba(26,21,48,.85);color:#fff;font-size:11px;font-weight:600;padding:5px 10px;border-radius:6px;font-family:var(--mono);letter-spacing:0.03em;backdrop-filter:blur(6px)}
.lesson-tile-badge-new{background:var(--highlight);color:var(--ink)}
.lesson-tile-body{padding:18px 20px;flex:1;display:flex;flex-direction:column}
.lesson-tile-track{display:inline-block;font-size:11px;font-weight:600;color:var(--accent);background:var(--accent-soft);padding:3px 9px;border-radius:5px;text-transform:uppercase;letter-spacing:0.04em;margin-bottom:10px;align-self:flex-start}
.lesson-tile-body h3{font-size:1.05rem;line-height:1.35;margin:0 0 .4em;font-weight:700}
.lesson-tile-body h3 a{color:var(--ink)}
.lesson-tile-body h3 a:hover{color:var(--brand)}
.lesson-tile-body p{font-size:13px;color:var(--ink-2);margin:0 0 12px;line-height:1.5;flex:1;display:-webkit-box;-webkit-line-clamp:3;line-clamp:3;-webkit-box-orient:vertical;overflow:hidden}
.lesson-tile-stats{display:flex;align-items:center;gap:14px;font-size:12px;color:var(--ink-3);padding-top:12px;border-top:1px solid var(--line-soft);flex-wrap:wrap}
.lesson-tile-stats li{display:inline-flex;align-items:center;gap:5px;font-weight:500}
.stat-glyph{display:inline-block;font-size:12px}

/* track-by-cat (pillar sections) */
.track-by-cat{padding:48px 0;background:var(--surface);border-top:1px solid var(--line);border-bottom:1px solid var(--line)}
.track-by-cat-row{display:grid;grid-template-columns:280px 1fr;gap:48px;align-items:start}
.track-by-cat-head{position:sticky;top:80px}
.track-by-cat-head h2{font-size:clamp(1.5rem,2.4vw,2.1rem);margin:.2em 0 .4em}
.track-aim{font-size:14px;color:var(--ink-2);margin:0 0 1.2em;line-height:1.5}
@media(max-width:880px){.track-by-cat-row{grid-template-columns:1fr;gap:20px}.track-by-cat-head{position:static}}

/* lesson stack (numbered list) */
.lesson-stack{display:flex;flex-direction:column;gap:0;padding:0}
.lesson-stack-item{display:grid;grid-template-columns:auto 1fr auto;gap:22px;padding:20px 22px;background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);align-items:center;transition:all .2s ease;list-style:none;margin-bottom:10px}
.lesson-stack-item:hover{border-color:var(--brand);transform:translateX(4px);box-shadow:var(--shadow)}
.lesson-stack-num{display:inline-flex;align-items:center;justify-content:center;width:46px;height:46px;background:var(--brand-soft);color:var(--brand);font-weight:800;font-size:1rem;border-radius:12px;font-family:var(--mono);flex-shrink:0;letter-spacing:-0.02em}
.lesson-stack-item:hover .lesson-stack-num{background:var(--brand);color:#fff}
.lesson-stack-body{min-width:0}
.lesson-stack-body h3{font-size:1.1rem;margin:0 0 .3em;font-weight:700;line-height:1.3}
.lesson-stack-body h3 a{color:var(--ink)}
.lesson-stack-body h3 a:hover{color:var(--brand)}
.lesson-stack-body p{font-size:14px;color:var(--ink-2);margin:0 0 10px;line-height:1.5;display:-webkit-box;-webkit-line-clamp:2;line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.lesson-stack-body .lesson-tile-stats{padding-top:0;border-top:0;font-size:12px}
.lesson-stack-go{flex-shrink:0;background:var(--paper-soft);color:var(--brand);font-weight:600;font-size:13px;padding:9px 16px;border-radius:8px;border:1px solid var(--line);white-space:nowrap;transition:all .15s ease}
.lesson-stack-item:hover .lesson-stack-go{background:var(--brand);color:#fff;border-color:var(--brand)}
@media(max-width:680px){.lesson-stack-item{grid-template-columns:auto 1fr;padding:16px}.lesson-stack-go{grid-column:1/-1;text-align:center;margin-top:8px}}

/* track-banner (category, tag, search, write-for-us) */
.track-banner{padding:40px 0 32px;background:var(--surface);border-bottom:1px solid var(--line)}
.lesson-rail-trail{font-size:13px;color:var(--ink-3);margin:0 0 14px;font-family:var(--mono)}
.lesson-rail-trail a{color:var(--ink-2);font-weight:500}
.lesson-rail-trail a:hover{color:var(--brand)}
.track-banner-title{font-size:clamp(2rem,3.8vw,2.8rem);font-weight:800;letter-spacing:-0.02em;margin:.1em 0 .4em}
.track-banner-deck{font-size:1.1rem;color:var(--ink-2);max-width:720px;margin-bottom:.8em;line-height:1.55}
.track-banner-meta{font-size:13px;color:var(--ink-3);font-family:var(--mono);margin:0;text-transform:uppercase;letter-spacing:0.04em}
.subtrack-pills{display:flex;flex-wrap:wrap;gap:8px;margin-top:18px}
.subtrack-pills a{display:inline-block;font-size:13px;color:var(--ink-2);background:var(--paper-soft);padding:7px 14px;border-radius:999px;font-weight:500;border:1px solid var(--line);transition:all .15s ease}
.subtrack-pills a:hover{background:var(--ink);color:#fff;border-color:var(--ink)}
.subtrack-pills a.is-on{background:var(--brand);color:#fff;border-color:var(--brand)}

.learn-empty{text-align:center;padding:80px 24px;background:var(--surface);border-radius:var(--radius-lg);border:1px dashed var(--line)}
.learn-empty h2{color:var(--ink-2);margin-bottom:.4em}
.learn-empty p{color:var(--ink-3);margin:0}

/* lesson-page (article) */
.lesson-page{padding:32px 0 64px}
.lesson-page-row{display:grid;grid-template-columns:280px 1fr;gap:48px;align-items:start}
.lesson-page-row-narrow{grid-template-columns:1fr;max-width:780px;margin:0 auto}

.lesson-rail{position:sticky;top:80px;display:flex;flex-direction:column;gap:18px}
.lesson-rail-card{background:var(--surface);padding:20px 22px;border-radius:var(--radius-lg);border:1px solid var(--line);box-shadow:var(--shadow-sm)}
.lesson-rail-track-tag{display:inline-block;font-size:11px;font-weight:700;color:var(--brand);background:var(--brand-soft);padding:4px 10px;border-radius:5px;text-transform:uppercase;letter-spacing:0.06em;margin-bottom:12px}
.lesson-rail-title{font-size:.95rem;font-weight:700;line-height:1.35;margin:0 0 14px;color:var(--ink)}
.lesson-rail-meta{display:flex;flex-direction:column;gap:8px;padding-top:12px;border-top:1px solid var(--line-soft)}
.lesson-rail-meta li{display:inline-flex;align-items:center;gap:8px;font-size:13px;color:var(--ink-2)}
.lesson-progress{margin-top:16px;padding-top:14px;border-top:1px solid var(--line-soft)}
.lesson-progress-label{display:block;font-size:11px;color:var(--ink-3);text-transform:uppercase;letter-spacing:0.06em;font-weight:600;margin-bottom:8px}
.lesson-progress-track{display:block;height:6px;background:var(--paper-soft);border-radius:3px;overflow:hidden}
.lesson-progress-bar{display:block;height:100%;background:linear-gradient(90deg,var(--brand) 0%,var(--accent) 100%);border-radius:3px;width:0%;transition:width .1s ease-out}

.lesson-toc{background:var(--surface);padding:20px 22px;border-radius:var(--radius-lg);border:1px solid var(--line)}
.lesson-toc-head{font-size:11px;color:var(--ink-3);text-transform:uppercase;letter-spacing:0.08em;margin:0 0 14px;font-weight:700;padding-bottom:10px;border-bottom:1px solid var(--line-soft)}
.lesson-toc ol{counter-reset:tt;display:flex;flex-direction:column;gap:4px}
.lesson-toc ol li{counter-increment:tt}
.lesson-toc a{display:grid;grid-template-columns:auto 1fr;gap:8px;padding:7px 10px;border-radius:6px;font-size:13px;line-height:1.4;color:var(--ink-2);align-items:start}
.lesson-toc a:hover{background:var(--paper-soft);color:var(--brand)}
.toc-step{font-size:10px;font-weight:700;color:var(--brand);background:var(--brand-soft);padding:2px 6px;border-radius:4px;font-family:var(--mono);align-self:start;margin-top:1px;letter-spacing:0.02em}
.toc-text{font-weight:500}

/* lesson-content */
.lesson-content{background:var(--surface);border-radius:var(--radius-lg);border:1px solid var(--line);overflow:hidden;box-shadow:var(--shadow-sm)}
.lesson-content-head{padding:36px 40px 28px;border-bottom:1px solid var(--line-soft)}
.lesson-track-chip{display:inline-block;font-size:11px;font-weight:700;color:var(--brand);background:var(--brand-soft);padding:5px 12px;border-radius:999px;text-transform:uppercase;letter-spacing:0.06em;margin-bottom:14px}
.lesson-content-title{font-size:clamp(1.8rem,3.4vw,2.6rem);font-weight:800;letter-spacing:-0.025em;line-height:1.15;margin:0 0 .5em;color:var(--ink)}
.lesson-content-deck{font-size:1.1rem;color:var(--ink-2);line-height:1.55;margin-bottom:1.4em;max-width:720px}
.lesson-content-byline{display:flex;align-items:center;justify-content:space-between;gap:20px;padding-top:18px;border-top:1px solid var(--line-soft);flex-wrap:wrap}
.lesson-author{display:flex;align-items:center;gap:12px}
.lesson-author-pic{display:inline-flex;align-items:center;justify-content:center;width:42px;height:42px;background:linear-gradient(135deg,var(--brand) 0%,var(--accent) 100%);color:#fff;border-radius:50%;font-weight:700;font-size:15px;font-family:var(--mono)}
.lesson-author-by{display:block;font-size:11px;color:var(--ink-3);text-transform:uppercase;letter-spacing:0.06em;font-weight:600;margin-bottom:1px}
.lesson-author-name{display:block;font-size:14px;font-weight:600;color:var(--ink)}
.lesson-author-name a{color:var(--ink)}
.lesson-author-name a:hover{color:var(--brand)}
.lesson-stats-strip{display:flex;gap:24px}
.lesson-stats-strip li{display:flex;flex-direction:column;align-items:flex-end;line-height:1.1}
.stat-num{font-family:var(--mono);font-weight:700;font-size:1.2rem;color:var(--ink);letter-spacing:-0.02em}
.stat-lab{font-size:10px;color:var(--ink-3);text-transform:uppercase;letter-spacing:0.06em;font-weight:600;margin-top:3px}

.lesson-cover{margin:0 auto;padding:0;max-width:1180px}
.lesson-cover img{width:100%;max-height:440px;object-fit:cover}

.lesson-body{padding:40px;font-size:1.05rem;line-height:1.75;color:var(--ink)}
.lesson-body p{margin:0 0 1.2em}
.lesson-body h2{font-size:1.55rem;margin:2em 0 .7em;font-weight:800;color:var(--ink);position:relative;padding-left:18px}
.lesson-body h2::before{content:'';position:absolute;left:0;top:.15em;bottom:.15em;width:4px;background:linear-gradient(180deg,var(--brand) 0%,var(--accent) 100%);border-radius:2px}
.lesson-body h3{font-size:1.25rem;margin:1.6em 0 .5em;font-weight:700}
.lesson-body h4{font-size:1.05rem;margin:1.4em 0 .5em;font-weight:600;color:var(--ink-2)}
.lesson-body blockquote{margin:1.4em 0;padding:18px 24px;background:var(--brand-tint);border-radius:var(--radius);border-left:4px solid var(--brand);color:var(--ink);font-style:normal;position:relative}
.lesson-body blockquote::before{content:'\1F4A1';margin-right:8px;font-style:normal}
.lesson-body ul,.lesson-body ol{margin:0 0 1.2em 1.4em;list-style:disc}
.lesson-body ol{list-style:decimal}
.lesson-body li{margin-bottom:.4em}
.lesson-body a{color:var(--brand);font-weight:500;text-decoration:underline;text-decoration-color:var(--brand-soft);text-decoration-thickness:2px;text-underline-offset:3px}
.lesson-body a:hover{text-decoration-color:var(--brand)}
.lesson-body img{margin:1.6em 0;border-radius:var(--radius);border:1px solid var(--line)}
.lesson-body code{font-family:var(--mono);background:var(--paper-soft);padding:2px 7px;font-size:.9em;border-radius:5px;color:var(--brand-deep)}
.lesson-body pre{background:var(--ink);color:#e0d4ff;padding:18px 22px;overflow-x:auto;font-size:.88em;margin:1.4em 0;border-radius:var(--radius);box-shadow:inset 0 1px 2px rgba(0,0,0,.2)}
.lesson-body pre code{background:none;color:inherit;padding:0}
.lesson-body table{border-collapse:separate;border-spacing:0;width:100%;margin:1.4em 0;font-size:.95em;border:1px solid var(--line);border-radius:var(--radius);overflow:hidden}
.lesson-body th,.lesson-body td{border-bottom:1px solid var(--line);padding:11px 16px;text-align:left}
.lesson-body th{font-size:12px;font-weight:700;background:var(--paper-soft);text-transform:uppercase;letter-spacing:0.04em;color:var(--ink-2)}
.lesson-body tr:last-child td{border-bottom:0}

.lesson-ad{display:block;margin:1.6em 0;padding:14px;background:var(--paper-soft);border:1px dashed var(--line);text-align:center;border-radius:var(--radius);font-size:12px;color:var(--ink-3)}

/* lesson footer */
.lesson-content-foot{padding:28px 40px;background:var(--paper-soft);border-top:1px solid var(--line-soft);display:flex;flex-direction:column;gap:18px}
.lesson-helpful{display:flex;align-items:center;gap:12px;flex-wrap:wrap}
.lesson-helpful-q{font-weight:600;color:var(--ink);font-size:14px;margin-right:8px}
.lesson-helpful-btn{background:var(--surface);border:1.5px solid var(--line);color:var(--ink-2);padding:9px 18px;border-radius:8px;font-weight:600;font-size:13px;cursor:pointer;transition:all .15s ease;font-family:var(--sans)}
.lesson-helpful-btn:hover{border-color:var(--brand);color:var(--brand);background:var(--brand-tint)}
.lesson-helpful-btn.is-voted{background:var(--brand);color:#fff;border-color:var(--brand)}
.lesson-tags,.lesson-share{display:flex;align-items:center;gap:8px;flex-wrap:wrap;font-size:13px;color:var(--ink-3)}
.lesson-tags span,.lesson-share span{font-weight:600;color:var(--ink-2);margin-right:4px}
.lesson-tag-pill{display:inline-block;background:var(--surface);color:var(--ink-2);padding:5px 12px;border-radius:999px;font-size:12px;font-weight:500;border:1px solid var(--line)}
.lesson-tag-pill:hover{background:var(--brand);color:#fff;border-color:var(--brand)}
.lesson-share-link{display:inline-block;background:var(--surface);color:var(--ink-2);padding:5px 14px;border-radius:6px;font-size:12px;font-weight:600;border:1px solid var(--line)}
.lesson-share-link:hover{background:var(--ink);color:#fff;border-color:var(--ink)}

@media(max-width:980px){.lesson-page-row{grid-template-columns:1fr}.lesson-rail{position:static;display:none}}
@media(max-width:600px){.lesson-content-head{padding:28px 24px}.lesson-body{padding:28px 24px}.lesson-content-foot{padding:20px 24px}.lesson-stats-strip{gap:18px}}

/* lesson faqzone */
.lesson-faqzone{padding:36px 40px;background:var(--paper-soft);border-top:1px solid var(--line-soft)}
.lesson-faqzone h2{font-size:1.5rem;margin:0 0 20px;padding:0}
.lesson-faqzone h2::before{display:none}
.lesson-qa{display:flex;flex-direction:column;gap:10px}
.lesson-qa-row{background:var(--surface);border:1px solid var(--line);border-radius:var(--radius);transition:all .2s ease;overflow:hidden}
.lesson-qa-row[open]{border-color:var(--brand);box-shadow:0 0 0 3px var(--brand-soft)}
.lesson-qa-row summary{padding:16px 20px;cursor:pointer;list-style:none;font-weight:600;font-size:.98rem;color:var(--ink);display:flex;align-items:center;gap:12px}
.lesson-qa-row summary::-webkit-details-marker{display:none}
.lesson-qa-row summary::before{content:'+';display:inline-flex;align-items:center;justify-content:center;width:24px;height:24px;background:var(--brand-soft);color:var(--brand);border-radius:6px;font-weight:700;font-size:14px;flex-shrink:0;transition:all .2s ease}
.lesson-qa-row[open] summary::before{content:'\2212';background:var(--brand);color:#fff}
.lesson-qa-row > div{padding:0 20px 18px 56px;font-size:.96rem;color:var(--ink-2);line-height:1.65}

/* nextup */
.lesson-nextup{padding:36px 40px;border-top:1px solid var(--line-soft);max-width:880px;margin:0 auto}
.lesson-nextup-head{font-size:1.4rem;margin:0 0 20px;padding:0}
.lesson-nextup-head::before{display:none}

/* teacher banner / page */
.teacher-banner{padding:40px 0;background:linear-gradient(135deg,var(--brand-tint) 0%,var(--paper) 100%);border-bottom:1px solid var(--line)}
.teacher-banner-row{display:grid;grid-template-columns:120px 1fr;gap:32px;align-items:center}
.teacher-pic{width:120px;height:120px;border-radius:50%;background:linear-gradient(135deg,var(--brand) 0%,var(--accent) 100%);overflow:hidden;display:flex;align-items:center;justify-content:center;color:#fff;font-weight:700;font-size:42px;box-shadow:var(--shadow-lg)}
.teacher-pic img{width:100%;height:100%;object-fit:cover}
.teacher-name{font-size:clamp(1.8rem,3.4vw,2.4rem);margin:.2em 0 .3em;font-weight:800;letter-spacing:-0.02em}
.teacher-stat{font-size:14px;color:var(--brand);font-weight:600;margin:0 0 1em;font-family:var(--mono);letter-spacing:0.02em;text-transform:uppercase}
.teacher-bio{font-size:1.05rem;color:var(--ink-2);max-width:720px;margin:0;line-height:1.6}
@media(max-width:560px){.teacher-banner-row{grid-template-columns:1fr;text-align:center}.teacher-pic{margin:0 auto}}

/* teacher tiers (write-for-us) */
.teacher-tiers{padding:32px 0}
.teacher-tiers-row{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
@media(max-width:760px){.teacher-tiers-row{grid-template-columns:1fr}}
.teacher-tier{background:var(--surface);padding:24px 26px;border-radius:var(--radius-lg);border:1px solid var(--line);transition:all .2s ease}
.teacher-tier:hover{transform:translateY(-3px);box-shadow:var(--shadow-lg);border-color:var(--brand-soft)}
.teacher-tier-glyph{display:inline-block;font-size:32px;margin-bottom:12px}
.teacher-tier h3{font-size:1.1rem;margin:0 0 .4em;font-weight:700}
.teacher-tier p{font-size:14px;color:var(--ink-2);margin:0;line-height:1.55}

.teacher-form-zone{padding:32px 0 64px}
.teacher-form-row{display:grid;grid-template-columns:1.6fr 1fr;gap:32px;align-items:start;max-width:1080px;margin:0 auto}
@media(max-width:880px){.teacher-form-row{grid-template-columns:1fr}}
.teacher-checklist{background:var(--surface);padding:22px 24px;border-radius:var(--radius-lg);border:1px solid var(--line);position:sticky;top:80px}
.teacher-checklist h4{font-size:11px;color:var(--brand);text-transform:uppercase;letter-spacing:0.08em;margin:0 0 14px;font-weight:700}
.teacher-checklist ul li{font-size:14px;color:var(--ink-2);padding:8px 0 8px 26px;position:relative;border-bottom:1px solid var(--line-soft);line-height:1.5}
.teacher-checklist ul li:last-child{border-bottom:0}
.teacher-checklist ul li::before{content:'\2713';position:absolute;left:0;top:8px;color:var(--beginner);font-weight:700;font-size:14px;background:var(--accent-soft);width:18px;height:18px;border-radius:50%;display:inline-flex;align-items:center;justify-content:center}

/* learn-bar (newsletter) */
.learn-bar{padding:48px 0;background:linear-gradient(135deg,var(--brand) 0%,var(--brand-deep) 100%);color:#fff}
.learn-bar-row{display:grid;grid-template-columns:1.4fr 1fr;gap:48px;align-items:center}
.learn-bar-eyebrow{display:inline-block;font-size:13px;color:var(--highlight);font-weight:600;margin:0 0 10px}
.learn-bar-text h3{color:#fff;font-size:1.6rem;font-weight:800;margin:0 0 .3em;letter-spacing:-0.015em}
.learn-bar-text p{margin:0;color:rgba(255,255,255,.8);font-size:14px;line-height:1.5}
.learn-bar-form{display:flex;gap:8px;background:rgba(255,255,255,.1);padding:6px;border-radius:14px;backdrop-filter:blur(8px)}
.learn-bar-form input{flex:1;background:transparent;border:0;color:#fff;padding:12px 16px;font-size:14px;outline:0;min-width:0;font-family:var(--sans)}
.learn-bar-form input::placeholder{color:rgba(255,255,255,.5)}
.learn-bar-form button{background:#fff;color:var(--brand);border:0;padding:12px 22px;border-radius:10px;font-weight:700;font-size:14px;cursor:pointer}
.learn-bar-form button:hover{background:var(--highlight);color:var(--ink)}
@media(max-width:760px){.learn-bar-row{grid-template-columns:1fr}.learn-bar-form{flex-direction:column}.learn-bar-form button,.learn-bar-form input{width:100%}}

/* ground (footer) */
.ground{background:var(--surface);padding:48px 0 24px;border-top:1px solid var(--line)}
.ground-row{display:grid;grid-template-columns:1.5fr 4fr;gap:48px;margin-bottom:32px}
.ground-brand .bar-brand-glyph{margin-bottom:14px}
.ground-blurb{font-size:14px;color:var(--ink-2);margin:0 0 8px;line-height:1.5}
.ground-note{font-size:13px;color:var(--ink-3);margin:0;font-style:italic}
.ground-cols{display:grid;grid-template-columns:repeat(4,1fr);gap:24px}
.ground-cols h6{font-size:11px;color:var(--ink);font-weight:800;letter-spacing:0.08em;text-transform:uppercase;margin:0 0 14px}
.ground-cols ul li{margin-bottom:8px;font-size:14px}
.ground-cols a{color:var(--ink-2)}
.ground-cols a:hover{color:var(--brand)}
.ground-strip{padding:16px 0;border-top:1px solid var(--line);display:flex;flex-wrap:wrap;align-items:center;gap:8px 16px;font-size:13px;color:var(--ink-3);font-family:var(--mono)}
.ground-strip span{font-weight:700;color:var(--ink-2);text-transform:uppercase;letter-spacing:0.06em;font-size:11px}
.ground-strip a{color:var(--ink-2);font-size:13px;font-family:var(--sans)}
.ground-base{display:flex;justify-content:space-between;padding-top:18px;margin-top:16px;border-top:1px solid var(--line);font-size:12px;color:var(--ink-3);flex-wrap:wrap;gap:8px;font-family:var(--mono)}
@media(max-width:880px){.ground-row{grid-template-columns:1fr}.ground-cols{grid-template-columns:1fr 1fr}}

/* pager */
.pager{margin-top:32px;display:flex;justify-content:center}
.pager ul{display:flex;gap:6px}
.pager a,.pager span{display:inline-flex;align-items:center;justify-content:center;min-width:38px;padding:8px 14px;font-size:13px;border:1.5px solid var(--line);background:var(--surface);border-radius:8px;color:var(--ink-2);font-weight:600;font-family:var(--mono)}
.pager a:hover{border-color:var(--brand);color:var(--brand);transform:translateY(-1px)}
.pager .active span,.pager .active a{background:var(--brand);color:#fff;border-color:var(--brand)}

/* 404 */
.learn-404{padding:96px 0;text-align:center}
.learn-404-row{max-width:560px;margin:0 auto}
.learn-404-glyph{display:block;font-size:72px;margin-bottom:18px}
.learn-404 h1{font-size:clamp(1.7rem,3vw,2.2rem);margin-bottom:.4em;font-weight:800}
.learn-404 p{color:var(--ink-2);font-size:1rem;margin-bottom:1.5em}
.learn-404-actions{display:flex;gap:14px;justify-content:center;flex-wrap:wrap;align-items:center}
.learn-404-text{font-weight:600;color:var(--brand);border-bottom:2px solid var(--brand-soft);padding-bottom:2px}
.learn-404-text:hover{border-color:var(--brand)}
.splash{padding:56px 0 40px;background:linear-gradient(135deg,var(--primary-tint) 0%,var(--accent-tint) 100%)}
.splash-inner{max-width:720px}
.splash-pill{display:inline-block;font-size:12px;font-weight:700;color:var(--primary);background:var(--surface);padding:5px 14px;border-radius:999px;border:1px solid var(--line);margin-bottom:18px}
.splash h1{letter-spacing:-.03em;margin-bottom:.35em}
.splash-sub{font-size:clamp(1.05rem,1.4vw,1.2rem);color:var(--ink-2);max-width:620px;margin-bottom:1.6em;line-height:1.55}
.splash-btns{display:flex;gap:14px;flex-wrap:wrap}
.btn-hot{display:inline-block;background:var(--primary);color:#fff;padding:13px 26px;border-radius:999px;font-weight:700;font-size:15px;transition:.2s}
.btn-hot:hover{background:var(--primary-dark);color:#fff;transform:translateY(-2px);box-shadow:var(--shadow-lg)}
.btn-subtle{color:var(--ink-2);font-weight:600;padding:13px 0;border-bottom:2px solid var(--line-2)}
.btn-subtle:hover{color:var(--primary);border-color:var(--primary)}

.zone{padding:40px 0}
.zone+.zone{padding-top:0}
.zone+.zone{margin-top:28px}
.zone-head{display:flex;align-items:flex-end;justify-content:space-between;gap:20px;margin-bottom:24px;flex-wrap:wrap}
.zone-head h2{margin:0}
.zone-see{font-size:14px;font-weight:600;color:var(--primary)}
.tile-grid{display:grid;grid-template-columns:repeat(2,1fr);gap:20px}
@media(max-width:880px){.tile-grid{grid-template-columns:repeat(2,1fr)}}
@media(max-width:520px){.tile-grid{grid-template-columns:1fr}}

.tile{background:var(--surface);border-radius:var(--radius);overflow:hidden;border:1px solid var(--line);transition:.2s;display:flex;flex-direction:column}
.tile:hover{border-color:var(--primary);box-shadow:var(--shadow-lg);transform:translateY(-3px)}
.tile-img{aspect-ratio:16/9;background:var(--bg-tint);overflow:hidden;position:relative}
.tile-img img{width:100%;height:100%;object-fit:cover;transition:transform .4s}
.tile:hover .tile-img img{transform:scale(1.04)}
.tile-label{position:absolute;top:10px;left:10px;background:var(--surface);color:var(--primary);font-size:10px;font-weight:700;padding:4px 10px;border-radius:999px;text-transform:uppercase;letter-spacing:.06em;border:1px solid var(--line)}
.tile-body{padding:16px 18px 18px;flex:1;display:flex;flex-direction:column}
.tile-body h3{font-size:.98rem;margin-bottom:.35em}
.tile-body h3 a{color:var(--ink)}
.tile-body h3 a:hover{color:var(--primary)}
.tile-body p{font-size:13px;color:var(--ink-2);margin:0 0 14px;line-height:1.5;flex:1;display:-webkit-box;-webkit-line-clamp:2;line-clamp:2;-webkit-box-orient:vertical;overflow:hidden}
.tile-foot{display:flex;align-items:center;gap:10px;font-size:12px;color:var(--ink-3);padding-top:12px;border-top:1px solid var(--line)}

.scroll-strip{padding:32px 0 48px;overflow:hidden}
.scroll-strip-head{display:flex;align-items:baseline;justify-content:space-between;margin-bottom:20px;gap:16px}
.scroll-strip-head h2{margin:0}
.scroll-track{display:flex;gap:16px;overflow-x:auto;scroll-snap-type:x mandatory;-webkit-overflow-scrolling:touch;padding-bottom:6px}
.scroll-track::-webkit-scrollbar{height:3px}
.scroll-track::-webkit-scrollbar-track{background:var(--bg-tint)}
.scroll-track::-webkit-scrollbar-thumb{background:var(--line-2);border-radius:3px}
.scroll-track .tile{flex:0 0 300px;scroll-snap-align:start}

.sidebar-split{display:grid;grid-template-columns:1fr 1fr;gap:40px;padding:36px 0}
@media(max-width:760px){.sidebar-split{grid-template-columns:1fr;gap:24px}}
.mini-label{font-size:11px;font-weight:700;color:var(--ink-3);letter-spacing:.12em;text-transform:uppercase;margin-bottom:14px}
.ranked-list{counter-reset:rl}
.ranked-list li{counter-increment:rl;border-bottom:1px solid var(--line);padding:12px 0 12px 34px;position:relative}
.ranked-list li::before{content:counter(rl,decimal-leading-zero);position:absolute;left:0;top:12px;font-family:var(--display);font-weight:700;color:var(--primary);font-size:14px}
.ranked-list a{color:var(--ink);font-weight:500}
.ranked-list a:hover{color:var(--primary)}
.pill-row{display:flex;flex-wrap:wrap;gap:8px}
.pill-row a{display:inline-block;background:var(--surface);color:var(--ink-2);padding:6px 14px;border-radius:999px;font-size:13px;font-weight:500;border:1px solid var(--line);transition:.15s}
.pill-row a:hover{background:var(--primary);color:#fff;border-color:var(--primary)}

.post-body-frame{max-width:780px;margin:0 auto;padding:0 24px}
.post-body{font-size:1.08rem;line-height:1.72}
.post-body p{margin:0 0 1.2em}
.post-body h2{font-size:1.7rem;margin:2em 0 .7em;font-weight:800}