:root{
  --bg:#f4f6fa;--card:#ffffff;--soft:#f8f9fc;--text:#171a22;
  --muted:#737b8b;--line:#e2e6ee;--accent:#6655e8;--hero:#181a29;
}
[data-theme="dark"]{
  --bg:#0b0d12;--card:#151820;--soft:#1b1e27;--text:#f4f5f8;
  --muted:#9aa2b1;--line:#292e39;--accent:#9688ff;--hero:#0e1018;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{margin:0;background:var(--bg);color:var(--text);font-family:Inter,system-ui,-apple-system,"Segoe UI",Arial,sans-serif}
a{text-decoration:none;color:inherit}

header{
  height:70px;background:var(--card);border-bottom:1px solid var(--line);
  display:flex;align-items:center;padding:0 28px;position:sticky;top:0;z-index:30
}
.brand{display:flex;align-items:center;gap:10px;font-size:20px;font-weight:850}
.logo{width:38px;height:38px;border-radius:11px;background:linear-gradient(135deg,#6b59ec,#9c7dff);display:grid;place-items:center;color:#fff}
nav{margin-left:auto;display:flex;align-items:center;gap:24px}
nav a{font-size:12px;color:var(--muted);font-weight:750}
nav a:hover{color:var(--accent)}
.theme{width:38px;height:38px;border:1px solid var(--line);background:var(--soft);color:var(--text);border-radius:10px;cursor:pointer}

.layout{
  width:100%;max-width:1500px;margin:0 auto;
  padding:22px 18px 55px;
  display:grid;grid-template-columns:300px minmax(620px,1fr) 300px;
  gap:22px;align-items:start
}
main{min-width:0}
.ad-side{width:300px}
.ad-frame{
  width:300px;height:250px;display:block;border:0;
  overflow:hidden;background:transparent
}

.hero{
  background:linear-gradient(135deg,#171927 0%,#282443 55%,#4a3d82 100%);
  color:#fff;border-radius:24px;padding:48px 46px;
  min-height:250px;display:flex;flex-direction:column;justify-content:center
}
.eyebrow{font-size:10px;letter-spacing:2px;color:#bdb5ff;font-weight:900}
.hero h1{font-size:42px;line-height:1.04;letter-spacing:-2px;margin:14px 0}
.hero p{max-width:720px;color:#d0d3dc;line-height:1.65;font-size:14px;margin:0}

.section{padding-top:30px}
.section h2{font-size:22px;margin:0 0 6px}
.section>p{font-size:12px;color:var(--muted);margin:0 0 18px}

.page{background:var(--card);border:1px solid var(--line);border-radius:22px;padding:30px}
.crumb{font-size:12px;color:var(--muted);margin-bottom:22px}
.crumb a{color:var(--accent);font-weight:800}
.title{display:flex;align-items:center;gap:14px}
.icon{width:58px;height:58px;border-radius:16px;background:var(--soft);display:grid;place-items:center;font-size:28px}
.title h1{margin:0;font-size:29px}
.title p{margin:5px 0 0;color:var(--muted);font-size:13px}

.grid{display:grid;grid-template-columns:repeat(3,minmax(0,1fr));gap:15px}
.subgrid,.contentgrid{display:grid;grid-template-columns:repeat(2,minmax(0,1fr));gap:15px}
.card{
  display:block;background:var(--card);border:1px solid var(--line);
  border-radius:16px;padding:20px;cursor:pointer;transition:.16s
}
.card:hover{transform:translateY(-2px);border-color:#c9c2fa;box-shadow:0 12px 30px #18213d12}
.topic-icon{font-size:25px}
.card h3{font-size:17px;margin:12px 0 7px}
.card p{font-size:12px;line-height:1.65;color:var(--muted);margin:0}
.open{display:inline-block;margin-top:15px;border:0;background:none;color:var(--accent);font-size:11px;font-weight:850;cursor:pointer;padding:0}
.number{font-size:10px;letter-spacing:1px;color:var(--accent);font-weight:900}

footer{border-top:1px solid var(--line);max-width:1500px;margin:auto;padding:20px 18px;color:var(--muted);font-size:11px}

/* Advertisement design: exactly 300 x 250, no internal page scroll */
.ad-body{margin:0;padding:0;overflow:hidden;background:transparent}
.ad{
  width:300px;height:250px;margin:0;padding:20px 18px;
  background:var(--card);border:1px solid var(--line);border-radius:14px;
  display:flex;flex-direction:column;align-items:center;text-align:center;
  overflow:hidden;box-shadow:0 8px 24px #18213d08
}
.ad-type{font-size:8px;letter-spacing:1.4px;color:var(--accent);font-weight:900}
.ad-icon{font-size:25px;margin:8px 0 5px}
.ad strong{font-size:15px;line-height:1.25}
.ad-text{
  font-size:10px;line-height:1.45;color:var(--muted);
  margin:8px 0;display:-webkit-box;-webkit-line-clamp:6;
  -webkit-box-orient:vertical;overflow:hidden
}
.ad-button{margin-top:auto;background:var(--accent);color:#fff;border-radius:8px;padding:8px 12px;font-size:9px;font-weight:850}

.modal{
  display:none;position:fixed;inset:0;background:rgba(5,7,12,.78);
  z-index:9999;align-items:center;justify-content:center;padding:20px
}
.modal.show{display:flex}
.popup{
  width:min(880px,100%);max-height:88vh;overflow:auto;
  background:var(--card);color:var(--text);border-radius:22px;
  padding:32px;position:relative;box-shadow:0 30px 90px #0009
}
.close{
  position:absolute;right:18px;top:18px;width:40px;height:40px;
  border-radius:50%;border:1px solid var(--line);background:var(--soft);
  color:var(--text);font-size:22px;cursor:pointer
}
.popup h2{font-size:28px;margin:0 50px 8px 0}
.popup h3{font-size:11px;letter-spacing:1px;text-transform:uppercase;color:var(--accent);margin:25px 0 9px}
.copy{white-space:pre-line;background:var(--soft);border:1px solid var(--line);border-radius:12px;padding:19px;font-size:14px;line-height:1.8}

@media(max-width:1200px){
  .layout{grid-template-columns:250px minmax(500px,1fr) 250px}
  .ad-side,.ad-frame,.ad{width:250px}
}
@media(max-width:980px){
  .layout{grid-template-columns:1fr}
  .ad-side{display:none}
  .grid{grid-template-columns:repeat(2,minmax(0,1fr))}
}
@media(max-width:650px){
  nav a{display:none}.layout{padding:12px}
  .hero{padding:32px 24px}.hero h1{font-size:32px}
  .page{padding:20px}.grid,.subgrid,.contentgrid{grid-template-columns:1fr}
}