:root {
  --bg: #f7f7f5;
  --surface: #ffffff;
  --text: #14161a;
  --text-2: #4b4f57;
  --muted: #8a8f98;
  --border: #e7e6e1;
  --primary: #2f6bf6;
  --primary-hover: #1f57db;
  --radius: 14px;
  --maxw: 720px;
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0e1016; --surface: #171a22; --text: #f0f2f6; --text-2: #b4bccb;
    --muted: #7d8698; --border: #262b36; --primary: #5b8bff; --primary-hover: #6f99ff;
  }
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}
a { color: var(--primary); text-decoration: none; }
a:hover { text-decoration: underline; }
img { max-width: 100%; }

/* Header */
.site-header {
  position: sticky; top: 0; z-index: 10;
  background: color-mix(in srgb, var(--surface) 88%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--border);
}
.site-header__in {
  max-width: 1080px; margin: 0 auto; padding: 14px 22px;
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 750; font-size: 19px; color: var(--text); }
.brand:hover { text-decoration: none; }
.brand svg { width: 30px; height: 34px; display: block; }
.site-nav { display: flex; align-items: center; gap: 20px; font-size: 14.5px; font-weight: 550; }
.site-nav a { color: var(--text-2); }
.btn-app {
  background: var(--primary); color: #fff !important; padding: 9px 16px;
  border-radius: 10px; font-weight: 650; font-size: 14px;
}
.btn-app:hover { background: var(--primary-hover); text-decoration: none; }

/* Layout */
.wrap { max-width: var(--maxw); margin: 0 auto; padding: 0 22px; }
.wrap-wide { max-width: 1080px; margin: 0 auto; padding: 0 22px; }

/* Article */
.article { padding: 44px 0 60px; }
.article__eyebrow { color: var(--primary); font-weight: 650; font-size: 13.5px; letter-spacing: .02em; text-transform: uppercase; }
.article h1 { font-size: clamp(28px, 5vw, 40px); line-height: 1.18; letter-spacing: -.02em; margin: 10px 0 12px; }
.article__meta { color: var(--muted); font-size: 14px; margin-bottom: 8px; }
.article__lead { font-size: 19px; color: var(--text-2); margin: 0 0 8px; }
.article h2 { font-size: 24px; letter-spacing: -.01em; margin: 40px 0 12px; }
.article h3 { font-size: 19px; margin: 28px 0 8px; }
.article p { margin: 0 0 18px; }
.article ul, .article ol { margin: 0 0 18px; padding-left: 22px; }
.article li { margin-bottom: 8px; }
.article strong { color: var(--text); }
.callout {
  background: var(--surface); border: 1px solid var(--border);
  border-left: 3px solid var(--primary); border-radius: 12px;
  padding: 16px 18px; margin: 24px 0; color: var(--text-2);
}
.callout strong { color: var(--text); }
hr { border: none; border-top: 1px solid var(--border); margin: 40px 0; }

/* Blog index */
.hero { padding: 60px 0 24px; text-align: center; }
.hero h1 { font-size: clamp(30px, 6vw, 46px); letter-spacing: -.02em; margin: 0 0 12px; }
.hero p { font-size: 19px; color: var(--text-2); max-width: 620px; margin: 0 auto; }
.post-list { display: grid; gap: 16px; padding: 20px 0 60px; }
.post-card {
  display: block; background: var(--surface); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 22px 24px; transition: border-color .15s, transform .12s;
}
.post-card:hover { border-color: color-mix(in srgb, var(--primary) 40%, var(--border)); transform: translateY(-2px); text-decoration: none; }
.post-card__cat { color: var(--primary); font-size: 13px; font-weight: 650; text-transform: uppercase; letter-spacing: .02em; }
.post-card h2 { font-size: 21px; margin: 6px 0 8px; color: var(--text); letter-spacing: -.01em; }
.post-card p { margin: 0; color: var(--text-2); font-size: 15.5px; }

/* Ad slot */
.ad {
  margin: 32px 0; padding: 8px 14px 14px; text-align: center;
  background: color-mix(in srgb, var(--text) 3%, var(--surface));
  border: 1px solid var(--border); border-radius: 12px; overflow: hidden;
}
.ad__label { display: block; font-size: 10.5px; font-weight: 600; letter-spacing: .08em; text-transform: uppercase; color: var(--muted); margin-bottom: 8px; }
.ad ins { display: block; min-height: 90px; }

/* Footer */
.site-footer { border-top: 1px solid var(--border); background: var(--surface); margin-top: 40px; }
.site-footer__in { max-width: 1080px; margin: 0 auto; padding: 32px 22px; display: flex; flex-wrap: wrap; gap: 8px 24px; align-items: center; justify-content: space-between; }
.site-footer a { color: var(--text-2); font-size: 14px; }
.site-footer .muted { color: var(--muted); font-size: 13.5px; }
.foot-links { display: flex; flex-wrap: wrap; gap: 18px; }

@media (max-width: 560px) {
  .site-nav { gap: 12px; font-size: 13.5px; }
  .site-nav .hide-sm { display: none; }
}