:root{
  --eh-bg:#07100d;
  --eh-bg-2:#0b1512;
  --eh-panel:#0f1b17;
  --eh-panel-2:#13241f;
  --eh-text:#effff7;
  --eh-muted:#9db7ad;
  --eh-border:rgba(135,255,203,.15);
  --eh-primary:#20e58f;
  --eh-cyan:#7cf7ff;
  --eh-warn:#ffd166;
  --eh-shadow:0 18px 60px rgba(0,0,0,.28);
  --eh-radius:8px;
}
:root[data-theme=light]{
  --eh-bg:#f7faf8;
  --eh-bg-2:#eef5f0;
  --eh-panel:#ffffff;
  --eh-panel-2:#edf7f1;
  --eh-text:#102019;
  --eh-muted:#52645b;
  --eh-border:rgba(20,80,55,.16);
  --eh-shadow:0 18px 50px rgba(21,60,42,.12);
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--eh-bg);color:var(--eh-text);font-family:Inter,system-ui,sans-serif;line-height:1.6}
body:before{content:"";position:fixed;inset:0;pointer-events:none;background:linear-gradient(rgba(124,247,255,.03) 1px,transparent 1px),linear-gradient(90deg,rgba(124,247,255,.03) 1px,transparent 1px);background-size:44px 44px;mask-image:linear-gradient(to bottom,#000,transparent 78%);z-index:-1}
a{color:inherit}
img{max-width:100%;height:auto}
h1,h2,h3{font-family:Poppins,Inter,sans-serif;line-height:1.08;margin:0 0 .8rem}
h1{font-size:clamp(2.35rem,5vw,5.5rem)}
h2{font-size:clamp(1.6rem,3vw,3rem)}
p{margin:0 0 1rem;color:var(--eh-muted)}
.skip-link{position:absolute;left:-999px;top:0}.skip-link:focus{left:1rem;z-index:10;background:var(--eh-primary);color:#03120c;padding:.7rem}
.site-header{position:sticky;top:0;z-index:20;border-bottom:1px solid var(--eh-border);background:color-mix(in srgb,var(--eh-bg) 86%,transparent);backdrop-filter:blur(18px)}
.header-inner{display:grid;grid-template-columns:auto minmax(220px,1fr) auto auto auto;gap:1rem;align-items:center;max-width:1240px;margin:0 auto;padding:.85rem 1rem}
.brand{display:inline-flex;align-items:center;gap:.6rem;font-weight:900;text-decoration:none}
.brand-mark{display:grid;place-items:center;width:38px;height:38px;border:1px solid rgba(32,229,143,.55);border-radius:8px;background:linear-gradient(135deg,rgba(32,229,143,.18),rgba(124,247,255,.08));color:var(--eh-primary);box-shadow:0 0 24px rgba(32,229,143,.12)}
.primary-nav ul{display:flex;gap:.8rem;list-style:none;margin:0;padding:0}
.primary-nav a{text-decoration:none;color:var(--eh-muted);font-weight:700}.primary-nav a:hover{color:var(--eh-text)}
.account-nav{display:flex;gap:.55rem;align-items:center}
.account-nav a{display:inline-flex;align-items:center;min-height:38px;border:1px solid var(--eh-border);border-radius:8px;padding:.45rem .7rem;text-decoration:none;color:var(--eh-text);font-weight:800;white-space:nowrap}
.account-nav__primary{background:var(--eh-primary);border-color:transparent!important;color:#03120c!important}
.header-search{position:relative}
.header-search input{width:100%;border:1px solid var(--eh-border);border-radius:8px;background:var(--eh-panel);color:var(--eh-text);padding:.75rem .9rem}
.search-results{position:absolute;left:0;right:0;top:calc(100% + .35rem);background:var(--eh-panel);border:1px solid var(--eh-border);border-radius:8px;box-shadow:var(--eh-shadow);overflow:hidden}
.search-results a{display:flex;justify-content:space-between;gap:1rem;padding:.75rem .9rem;text-decoration:none;border-bottom:1px solid var(--eh-border)}
.search-results small{color:var(--eh-primary)}
.theme-toggle,.icon-button{width:42px;height:42px;border:1px solid var(--eh-border);border-radius:8px;background:var(--eh-panel);color:var(--eh-text);cursor:pointer}
.site-main{min-height:70vh}
.hero{padding:4rem 1rem 2rem}
.hero-grid{max-width:1240px;margin:auto;display:grid;grid-template-columns:minmax(0,1.05fr) minmax(320px,.95fr);gap:2rem;align-items:center}
.hero-copy p{font-size:1.12rem;max-width:680px}
.kicker{display:inline-block;color:var(--eh-primary);font-weight:900;text-transform:uppercase;letter-spacing:.08em;font-size:.78rem;margin-bottom:.65rem}
.hero-actions,.meta-row,.lesson-actions{display:flex;gap:.75rem;flex-wrap:wrap;align-items:center}
.button{display:inline-flex;align-items:center;justify-content:center;min-height:44px;border-radius:8px;padding:.78rem 1rem;font-weight:900;text-decoration:none;border:1px solid var(--eh-border);cursor:pointer}
.button-primary{background:var(--eh-primary);color:#03120c;border-color:transparent}.button-ghost{background:var(--eh-panel);color:var(--eh-text)}
.terminal-panel{border:1px solid var(--eh-border);border-radius:8px;background:linear-gradient(145deg,var(--eh-panel),var(--eh-bg-2));box-shadow:var(--eh-shadow);overflow:hidden}
.terminal-bar{display:flex;gap:.45rem;padding:.8rem;border-bottom:1px solid var(--eh-border)}.terminal-bar span{width:11px;height:11px;border-radius:50%;background:var(--eh-primary)}.terminal-bar span:nth-child(2){background:var(--eh-warn)}.terminal-bar span:nth-child(3){background:var(--eh-cyan)}
pre{overflow:auto;border:1px solid var(--eh-border);border-radius:8px;background:#06110d;color:#b7ffd8;padding:1rem}code{font-family:"SFMono-Regular",Consolas,monospace}
.terminal-panel pre{border:0;margin:0;border-radius:0;min-height:300px}
.track-strip{display:flex;gap:.75rem;overflow:auto;max-width:1240px;margin:0 auto;padding:0 1rem 2rem}
.track-strip a{flex:0 0 auto;text-decoration:none;border:1px solid var(--eh-border);border-radius:8px;background:var(--eh-panel);padding:.72rem 1rem;color:var(--eh-muted);font-weight:800}
.page-section{max-width:1240px;margin:0 auto;padding:3rem 1rem}.page-section.narrow{max-width:850px}
.section-head{max-width:760px;margin-bottom:1.4rem}
.course-grid,.post-grid{display:grid;grid-template-columns:repeat(auto-fit,minmax(280px,1fr));gap:1rem}
.course-card,.post-card{border:1px solid var(--eh-border);border-radius:8px;background:var(--eh-panel);overflow:hidden;box-shadow:var(--eh-shadow)}
.course-thumb,.post-thumb{display:grid;place-items:center;aspect-ratio:16/9;background:linear-gradient(135deg,rgba(32,229,143,.15),rgba(124,247,255,.12));text-decoration:none}
.course-thumb span{font-size:3rem;color:var(--eh-primary);font-weight:900}
.course-thumb img,.post-thumb img{width:100%;height:100%;object-fit:cover}
.course-card__body,.post-card{padding:1rem}.course-card h2,.post-card h2{font-size:1.25rem}.course-card h2 a,.post-card h2 a{text-decoration:none}
.meta-row span{border:1px solid var(--eh-border);border-radius:8px;padding:.32rem .55rem;color:var(--eh-muted);font-size:.86rem;font-weight:800}
.inline-link{color:var(--eh-primary);font-weight:900;text-decoration:none}
.split-band{display:grid;grid-template-columns:1fr 1fr;gap:2rem;border-block:1px solid var(--eh-border);max-width:none;padding-inline:max(1rem,calc((100vw - 1240px)/2))}
.feature-list{display:grid;gap:.65rem}.feature-list p{padding:.9rem;border:1px solid var(--eh-border);border-radius:8px;background:var(--eh-panel);margin:0}
.course-hero{padding:3rem 1rem;border-bottom:1px solid var(--eh-border);background:radial-gradient(circle at 70% 10%,rgba(32,229,143,.16),transparent 30%)}
.course-hero>div{max-width:1020px;margin:auto}
.learn-layout{display:grid;grid-template-columns:310px minmax(0,1fr);gap:1.25rem;max-width:1320px;margin:0 auto;padding:1.25rem 1rem 3rem}
.course-rail{min-width:0}
.course-sidebar-toggle{display:none;border:1px solid var(--eh-border);border-radius:8px;background:var(--eh-primary);color:#03120c;font-weight:900;min-height:44px;padding:.75rem 1rem;text-align:left}
.course-sidebar-toggle:before{content:"+";margin-right:.5rem}
.course-sidebar{position:sticky;top:82px;align-self:start;max-height:calc(100vh - 100px);overflow:auto;border:1px solid var(--eh-border);border-radius:8px;background:var(--eh-panel)}
.course-sidebar__head{padding:1rem;border-bottom:1px solid var(--eh-border)}
.course-sidebar details{border-bottom:1px solid var(--eh-border)}.course-sidebar summary{cursor:pointer;padding:.85rem 1rem;font-weight:900}
.course-sidebar ol{list-style:none;margin:0;padding:0 .55rem .7rem}.course-sidebar li a{display:grid;grid-template-columns:1fr auto;gap:.7rem;padding:.55rem;border-radius:8px;text-decoration:none;color:var(--eh-muted)}
.course-sidebar li.is-active a,.course-sidebar li a:hover{background:var(--eh-panel-2);color:var(--eh-text)}.course-sidebar li.is-done a:before{content:"✓";color:var(--eh-primary)}.course-sidebar li.is-locked a{opacity:.55}
.lesson-content{min-width:0;border:1px solid var(--eh-border);border-radius:8px;background:var(--eh-panel);padding:1.25rem}
.lesson-progress{position:sticky;top:70px;z-index:15;height:5px;background:var(--eh-bg-2)}.lesson-progress span{display:block;height:100%;background:linear-gradient(90deg,var(--eh-primary),var(--eh-cyan))}
.lesson-head{display:flex;justify-content:space-between;gap:1rem;align-items:flex-start;margin-bottom:1rem}
.prose{font-size:1.03rem}.prose h2,.prose h3{margin-top:2rem}.prose a{color:var(--eh-primary)}.prose img,.post-cover img{border-radius:8px;border:1px solid var(--eh-border)}
.resource-link{display:inline-flex;margin:1rem 0;padding:.8rem 1rem;border-radius:8px;background:var(--eh-panel-2);text-decoration:none;color:var(--eh-primary);font-weight:900}
.lesson-nav{display:flex;justify-content:space-between;gap:1rem;margin-top:2rem}.lesson-nav a{border:1px solid var(--eh-border);border-radius:8px;padding:.8rem 1rem;text-decoration:none;background:var(--eh-panel-2)}
.breadcrumbs{display:flex;gap:.45rem;flex-wrap:wrap;color:var(--eh-muted);font-size:.88rem;margin-bottom:1rem}.breadcrumbs a{text-decoration:none;color:var(--eh-primary)}.breadcrumbs>*:not(:last-child):after{content:"/";color:var(--eh-muted);margin-left:.45rem}
.comments-area{margin-top:2rem;border-top:1px solid var(--eh-border);padding-top:1rem}.comment-list{padding-left:1.2rem}
.site-footer{border-top:1px solid var(--eh-border);background:var(--eh-bg-2);padding:2rem 1rem}.footer-grid{max-width:1240px;margin:auto;display:grid;grid-template-columns:1.4fr 1fr 1fr;gap:1rem}
.ad-slot{max-width:1240px;margin:1rem auto;padding:0 1rem}
.ad-slot .widget{display:grid;place-items:center;min-height:90px;border:1px dashed var(--eh-border);border-radius:8px;background:var(--eh-panel);overflow:hidden}
.ad-slot--ad-sidebar{padding:0;margin:1rem 0}.ad-slot--ad-sidebar .widget{min-height:250px}
.ad-slot--ad-in-content .widget{min-height:120px}
@media (max-width:900px){
  .header-inner{grid-template-columns:1fr auto}.header-search,.primary-nav,.account-nav{grid-column:1/-1}.primary-nav ul,.account-nav{overflow:auto}
  .hero-grid,.split-band,.learn-layout{grid-template-columns:1fr}
  .course-sidebar-toggle{display:block;position:sticky;top:74px;z-index:12}
  .course-rail{display:none}
  .course-sidebar{display:block;position:relative;top:0;max-height:62vh}
  .learn-layout.is-sidebar-open .course-rail{display:block}
  .lesson-head{display:block}.footer-grid{grid-template-columns:1fr}
}
@media (max-width:560px){
  .hero{padding-top:2rem}.page-section{padding-block:2rem}.meta-row span{font-size:.78rem}.lesson-content{padding:1rem}
}