:root{
  --bg:#0b1117;
  --bg-soft:#111a23;
  --panel:#121c26;
  --panel-2:#172433;
  --text:#eef4f8;
  --muted:#a7b3be;
  --line:rgba(255,255,255,.12);
  --accent:#f97316;
  --accent-2:#ffb15c;
  --code:#071018;
  --shadow:0 24px 60px rgba(0,0,0,.35);
  --radius:22px;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0;
  font-family:Inter,Segoe UI,Roboto,Arial,sans-serif;
  color:var(--text);
  background:
    radial-gradient(circle at top left, rgba(249,115,22,.22), transparent 36rem),
    radial-gradient(circle at top right, rgba(255,177,92,.11), transparent 30rem),
    linear-gradient(180deg,#081018 0%,#0b1117 42%,#090d12 100%);
  line-height:1.65;
}
a{color:inherit;text-decoration:none}
img{max-width:100%;height:auto}
.container{width:min(1160px,92%);margin:auto}
.topbar{
  position:sticky;top:0;z-index:50;
  backdrop-filter:blur(18px);
  background:rgba(8,16,24,.82);
  border-bottom:1px solid var(--line);
}
.nav{
  min-height:72px;
  display:flex;
  align-items:center;
  justify-content:space-between;
  gap:1rem;
}
.brand{
  display:flex;
  align-items:center;
  gap:.75rem;
  font-weight:900;
  letter-spacing:.2px;
}
.logo{
  width:42px;height:42px;
  border-radius:14px;
  display:grid;place-items:center;
  background:linear-gradient(135deg,var(--accent),#9a3412);
  box-shadow:0 12px 30px rgba(249,115,22,.28);
  font-weight:900;
}
.navlinks{
  display:flex;
  align-items:center;
  gap:1.15rem;
  color:var(--muted);
  font-weight:700;
  font-size:.95rem;
}
.navlinks a:hover{color:var(--text)}
.menu-btn{
  display:none;
  border:1px solid var(--line);
  background:var(--panel);
  color:var(--text);
  border-radius:12px;
  padding:.55rem .75rem;
}
.hero{padding:72px 0 48px}
.hero-grid{
  display:grid;
  grid-template-columns:minmax(0,1.15fr) minmax(280px,.85fr);
  align-items:center;
  gap:3rem;
}
.badge{
  display:inline-flex;
  align-items:center;
  gap:.5rem;
  padding:.45rem .8rem;
  border:1px solid rgba(249,115,22,.35);
  color:#ffd8b7;
  background:rgba(249,115,22,.11);
  border-radius:999px;
  font-weight:800;
  font-size:.9rem;
}
h1,h2,h3{line-height:1.15;margin:0 0 1rem}
h1{
  font-size:clamp(2.7rem,6vw,5.6rem);
  letter-spacing:-.06em;
}
h1 span,.accent{color:var(--accent-2)}
.lead{
  font-size:clamp(1.08rem,2vw,1.3rem);
  color:#d2dce5;
  max-width:780px;
  margin:0 0 1.5rem;
}
.actions{
  display:flex;
  flex-wrap:wrap;
  gap:.9rem;
  margin-top:1.5rem;
}
.btn{
  display:inline-flex;
  align-items:center;
  justify-content:center;
  gap:.55rem;
  padding:.88rem 1.15rem;
  border-radius:14px;
  border:1px solid transparent;
  font-weight:900;
  transition:.2s ease;
}
.btn-primary{
  color:#111827;
  background:linear-gradient(135deg,var(--accent-2),var(--accent));
  box-shadow:0 18px 34px rgba(249,115,22,.24);
}
.btn-primary:hover{transform:translateY(-2px)}
.btn-secondary{
  border-color:var(--line);
  background:rgba(255,255,255,.05);
  color:var(--text);
}
.btn-secondary:hover{background:rgba(255,255,255,.09)}
.cover-card{
  position:relative;
  max-width:430px;
  justify-self:center;
}
.cover-glow{
  position:absolute;
  inset:8% 0 -4%;
  background:rgba(249,115,22,.23);
  filter:blur(45px);
  border-radius:40px;
}
.cover-card img{
  position:relative;
  border-radius:22px;
  box-shadow:var(--shadow);
  border:1px solid rgba(255,255,255,.14);
}
.stats{
  display:grid;
  grid-template-columns:repeat(4,1fr);
  gap:1rem;
  margin-top:3rem;
}
.stat{
  padding:1.25rem;
  background:rgba(255,255,255,.045);
  border:1px solid var(--line);
  border-radius:18px;
}
.stat strong{
  display:block;
  font-size:1.6rem;
  color:#fff;
}
.stat span{color:var(--muted);font-weight:700}
.section{padding:56px 0}
.section-head{
  display:flex;
  justify-content:space-between;
  align-items:end;
  gap:1rem;
  margin-bottom:1.5rem;
}
.section h2{
  font-size:clamp(2rem,4vw,3rem);
  letter-spacing:-.04em;
}
.section-intro{
  color:var(--muted);
  max-width:720px;
  margin:.25rem 0 0;
}
.grid{display:grid;gap:1rem}
.grid-3{grid-template-columns:repeat(3,1fr)}
.grid-4{grid-template-columns:repeat(4,1fr)}
.card{
  background:linear-gradient(180deg,rgba(255,255,255,.065),rgba(255,255,255,.035));
  border:1px solid var(--line);
  border-radius:var(--radius);
  padding:1.25rem;
  box-shadow:0 16px 40px rgba(0,0,0,.18);
}
.card h3{font-size:1.18rem}
.card p{color:var(--muted);margin:.25rem 0 0}
.icon{
  width:48px;height:48px;
  border-radius:15px;
  display:grid;place-items:center;
  background:rgba(249,115,22,.13);
  color:var(--accent-2);
  border:1px solid rgba(249,115,22,.25);
  font-weight:900;
  margin-bottom:1rem;
}
.lesson-list{
  display:grid;
  grid-template-columns:repeat(3,1fr);
  gap:1rem;
}
.lesson-card{
  display:flex;
  flex-direction:column;
  min-height:220px;
  background:linear-gradient(180deg,rgba(23,36,51,.95),rgba(18,28,38,.95));
  border:1px solid var(--line);
  border-radius:20px;
  padding:1.15rem;
  transition:.2s ease;
}
.lesson-card:hover{
  transform:translateY(-3px);
  border-color:rgba(249,115,22,.45);
}
.lesson-num{
  color:var(--accent-2);
  font-weight:900;
  font-size:.88rem;
  text-transform:uppercase;
  letter-spacing:.08em;
}
.lesson-card h3{margin:.5rem 0 .55rem;font-size:1.15rem}
.lesson-card p{color:var(--muted);margin:0 0 1rem}
.lesson-card .link{
  margin-top:auto;
  color:#ffd2ad;
  font-weight:900;
}
.cta{
  background:
    radial-gradient(circle at top left,rgba(249,115,22,.22),transparent 28rem),
    linear-gradient(135deg,rgba(23,36,51,.98),rgba(12,18,26,.98));
  border:1px solid rgba(249,115,22,.24);
  border-radius:28px;
  padding:2rem;
  display:grid;
  grid-template-columns:1.2fr .8fr;
  align-items:center;
  gap:1.5rem;
}
.footer{
  padding:36px 0;
  border-top:1px solid var(--line);
  color:var(--muted);
}
.footer-grid{
  display:flex;
  justify-content:space-between;
  gap:1rem;
  flex-wrap:wrap;
}
.breadcrumb{
  color:var(--muted);
  font-weight:700;
  font-size:.92rem;
  margin-bottom:1.1rem;
}
.lesson-layout{
  display:grid;
  grid-template-columns:280px minmax(0,1fr);
  gap:2rem;
  padding:46px 0 60px;
}
.sidebar{
  position:sticky;
  top:92px;
  align-self:start;
  background:rgba(18,28,38,.82);
  border:1px solid var(--line);
  border-radius:22px;
  padding:1rem;
}
.sidebar-title{
  font-weight:950;
  margin:.25rem 0 .75rem;
}
.sidebar a{
  display:block;
  padding:.55rem .65rem;
  border-radius:12px;
  color:var(--muted);
  font-weight:750;
  font-size:.94rem;
}
.sidebar a:hover,.sidebar a.active{
  color:var(--text);
  background:rgba(249,115,22,.13);
}
.article{
  background:rgba(255,255,255,.04);
  border:1px solid var(--line);
  border-radius:28px;
  padding:clamp(1.15rem,3vw,2.1rem);
}
.article h1{font-size:clamp(2.2rem,5vw,4rem)}
.article h2{font-size:1.55rem;margin-top:2rem}
.article p,.article li{color:#d3dde5}
.article ul{padding-left:1.25rem}
pre{
  background:var(--code);
  border:1px solid rgba(255,255,255,.12);
  border-radius:18px;
  padding:1.1rem;
  overflow:auto;
  box-shadow:inset 0 0 0 1px rgba(249,115,22,.06);
}
code{
  font-family:"Courier New",Consolas,monospace;
  color:#f8fafc;
}
.inline-code{
  background:rgba(255,255,255,.08);
  border:1px solid var(--line);
  padding:.1rem .35rem;
  border-radius:7px;
  color:#fff;
}
.note{
  border-left:4px solid var(--accent);
  background:rgba(249,115,22,.1);
  border-radius:16px;
  padding:1rem;
  color:#ffe3cc;
}
.lesson-nav{
  display:flex;
  justify-content:space-between;
  gap:1rem;
  margin-top:2rem;
}
.lesson-nav a{
  flex:1;
  border:1px solid var(--line);
  border-radius:16px;
  padding:1rem;
  color:var(--text);
  background:rgba(255,255,255,.045);
  font-weight:900;
}
.lesson-nav a:last-child{text-align:right}
.promo-mini{
  display:grid;
  grid-template-columns:90px 1fr;
  gap:1rem;
  align-items:center;
  margin-top:1.25rem;
  border:1px solid rgba(249,115,22,.3);
  background:rgba(249,115,22,.09);
  border-radius:18px;
  padding:1rem;
}
.promo-mini img{border-radius:12px}
@media(max-width:960px){
  .hero-grid,.cta,.lesson-layout{grid-template-columns:1fr}
  .stats,.grid-4{grid-template-columns:repeat(2,1fr)}
  .grid-3,.lesson-list{grid-template-columns:repeat(2,1fr)}
  .sidebar{position:static}
}
@media(max-width:720px){
  .menu-btn{display:inline-flex}
  .navlinks{
    display:none;
    position:absolute;
    left:4%;
    right:4%;
    top:72px;
    flex-direction:column;
    align-items:flex-start;
    padding:1rem;
    background:#0b1117;
    border:1px solid var(--line);
    border-radius:18px;
  }
  .navlinks.open{display:flex}
  .stats,.grid-3,.grid-4,.lesson-list{grid-template-columns:1fr}
  .hero{padding-top:44px}
  .lesson-nav{flex-direction:column}
  .lesson-nav a:last-child{text-align:left}
  .promo-mini{grid-template-columns:1fr}
}