/* Тушэм - дизайн-система сайта о потолках. Палитра: прохладная, «воздушная» (потолок/небо). */
:root{
  --bg:#eef3f6;          /* облачно-серый фон */
  --bg-soft:#f6f9fb;
  --card:#ffffff;
  --ink:#19232e;         /* сланцево-чёрный текст */
  --muted:#5d6b78;
  --line:#dde6ec;
  --brand:#1f6e8c;       /* глубокий тёплый-сине-зелёный (teal) */
  --brand-d:#185a73;
  --brand-l:#2e93b0;
  --accent:#eaf3f6;      /* лёгкая заливка */
  --ring:rgba(31,110,140,.18);
  --shadow:0 1px 2px rgba(20,40,60,.04),0 10px 30px rgba(20,40,60,.08);
  --radius:16px;
}
*{box-sizing:border-box;margin:0;padding:0}
html{scroll-behavior:smooth}
body{font:16px/1.65 -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,"Helvetica Neue",Arial,sans-serif;color:var(--ink);background:var(--bg);-webkit-font-smoothing:antialiased}
img{max-width:100%;display:block}
a{color:var(--brand)}
.wrap{max-width:1080px;margin:0 auto;padding:0 20px}

/* Header */
header.site{position:sticky;top:0;z-index:40;background:rgba(238,243,246,.9);backdrop-filter:saturate(160%) blur(10px);border-bottom:1px solid var(--line)}
.site .nav{display:flex;align-items:center;justify-content:space-between;height:64px;gap:16px}
.logo{display:flex;align-items:center;gap:9px;font-weight:800;font-size:21px;letter-spacing:.4px;color:var(--ink);text-decoration:none}
.logo svg{width:26px;height:26px;flex:0 0 auto}
.logo b{color:var(--brand)}
.site nav.links{display:flex;gap:22px}
.site nav.links a{color:var(--muted);text-decoration:none;font-size:15px;font-weight:500}
.site nav.links a:hover{color:var(--brand)}
.btn{display:inline-flex;align-items:center;justify-content:center;gap:8px;border:0;cursor:pointer;font:inherit;font-weight:700;text-decoration:none;border-radius:12px;transition:transform .12s,box-shadow .2s,background .2s}
.btn-primary{background:var(--brand);color:#fff;padding:13px 22px;box-shadow:0 6px 18px var(--ring)}
.btn-primary:hover{background:var(--brand-d);transform:translateY(-1px)}
.btn-ghost{background:#fff;color:var(--ink);border:1px solid var(--line);padding:13px 20px}
.btn-ghost:hover{border-color:var(--brand);color:var(--brand)}
.btn-sm{padding:9px 16px;font-size:14px;border-radius:10px}

/* Hero */
.hero{position:relative;overflow:hidden;border-bottom:1px solid var(--line)}
.hero .hero-bg{position:absolute;inset:0;width:100%;height:100%;object-fit:cover;z-index:0}
.hero .hero-shade{position:absolute;inset:0;z-index:1;background:linear-gradient(100deg,rgba(16,30,42,.78) 0%,rgba(16,30,42,.55) 42%,rgba(16,30,42,.15) 100%)}
.hero .hero-inner{position:relative;z-index:2;padding:84px 0 76px;color:#fff;max-width:620px}
.hero h1{font-size:clamp(28px,4.4vw,46px);line-height:1.1;letter-spacing:-.5px}
.hero p.sub{margin:18px 0 28px;font-size:clamp(16px,2vw,19px);color:#e8eef2;max-width:540px}
.hero .cta{display:flex;gap:12px;flex-wrap:wrap}

/* Sections */
section{padding:54px 0}
section.alt{background:var(--bg-soft)}
h2{font-size:clamp(24px,3vw,32px);letter-spacing:-.3px;margin-bottom:8px}
.lead{color:var(--muted);font-size:17px;margin-bottom:28px;max-width:680px}
.grid{display:grid;grid-template-columns:repeat(3,1fr);gap:18px}
.grid-2{display:grid;grid-template-columns:repeat(2,1fr);gap:18px}
.card{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);overflow:hidden;box-shadow:var(--shadow);transition:transform .15s,box-shadow .2s}
.card:hover{transform:translateY(-3px);box-shadow:0 14px 36px rgba(20,40,60,.12)}
.card .ph{aspect-ratio:16/10;width:100%;object-fit:cover;background:var(--accent)}
.card .pad{padding:18px 20px}
.card h3,.card h4{font-size:18px;margin-bottom:6px}
.card p{color:var(--muted);font-size:14.5px}
.card a.more{display:inline-block;margin-top:10px;color:var(--brand);font-weight:600;text-decoration:none;font-size:14.5px}

/* Steps */
.steps{display:grid;grid-template-columns:repeat(3,1fr);gap:18px;counter-reset:s}
.step{background:var(--card);border:1px solid var(--line);border-radius:var(--radius);padding:24px 22px 22px 66px;position:relative;box-shadow:var(--shadow)}
.step::before{counter-increment:s;content:counter(s);position:absolute;left:20px;top:22px;width:32px;height:32px;border-radius:50%;background:var(--brand);color:#fff;display:grid;place-items:center;font-weight:800}
.step h4{font-size:17px;margin-bottom:6px}.step p{color:var(--muted);font-size:14.5px}

/* CTA band */
.cta-band{background:linear-gradient(120deg,var(--brand),var(--brand-l));color:#fff;border-radius:22px;padding:44px;text-align:center}
.cta-band h2{color:#fff}.cta-band p{opacity:.94;margin:10px 0 22px;font-size:17px}
.cta-band .btn-primary{background:#fff;color:var(--brand)}
.cta-band .btn-primary:hover{background:#eef6f9}

/* Footer */
footer.site{border-top:1px solid var(--line);background:var(--bg-soft);color:var(--muted);font-size:14px;padding:34px 0;margin-top:8px}
footer.site .cols{display:flex;justify-content:space-between;gap:24px;flex-wrap:wrap}
footer.site a{color:var(--muted);text-decoration:none}
footer.site a:hover{color:var(--brand)}
footer.site .fcol h5{color:var(--ink);font-size:15px;margin-bottom:10px}
footer.site .fcol a{display:block;padding:3px 0}

/* Article */
.article{background:#fff}
.crumbs{font-size:13px;color:var(--muted);padding:16px 0}
.crumbs a{color:var(--muted);text-decoration:none}.crumbs a:hover{color:var(--brand)}
.article-hero{max-width:860px;margin:0 auto;padding:0 20px}
.article-hero h1{font-size:clamp(26px,3.6vw,38px);line-height:1.15;letter-spacing:-.4px;margin:6px 0 14px}
.article-hero .meta{color:var(--muted);font-size:14px;margin-bottom:20px}
.article-body{max-width:760px;margin:0 auto;padding:0 20px 10px;font-size:17px;line-height:1.75}
.article-body h2{margin:34px 0 12px;font-size:25px}
.article-body h3{margin:24px 0 8px;font-size:20px}
.article-body p{margin:0 0 16px}
.article-body ul,.article-body ol{margin:0 0 16px 22px}
.article-body li{margin:6px 0}
.article-body figure{margin:24px 0}
.article-body figure img{border-radius:var(--radius);width:100%;border:1px solid var(--line)}
.article-body figcaption{font-size:12.5px;color:var(--muted);margin-top:7px;text-align:center}
.article-body .credit{font-size:11px;color:#9aa6b0}
.callout{background:var(--accent);border:1px solid var(--line);border-left:4px solid var(--brand);border-radius:12px;padding:16px 18px;margin:22px 0}
.faq{margin:28px 0}
.faq details{border:1px solid var(--line);border-radius:12px;padding:4px 16px;margin:10px 0;background:#fff}
.faq summary{cursor:pointer;font-weight:600;padding:12px 0;list-style:none}
.faq summary::-webkit-details-marker{display:none}
.faq details[open] summary{border-bottom:1px solid var(--line)}
.faq details p{padding:12px 0;color:var(--muted)}
.related{max-width:860px;margin:10px auto 0;padding:0 20px}
.related h2{font-size:22px;margin-bottom:16px}
.related .grid{grid-template-columns:repeat(3,1fr)}
.cta-inline{max-width:760px;margin:30px auto;padding:0 20px}
.cta-inline .box{background:linear-gradient(120deg,var(--brand),var(--brand-l));color:#fff;border-radius:18px;padding:26px 28px;display:flex;align-items:center;justify-content:space-between;gap:18px;flex-wrap:wrap}
.cta-inline .box h3{font-size:20px}.cta-inline .box p{opacity:.92;font-size:15px}
.cta-inline .box .btn-primary{background:#fff;color:var(--brand);white-space:nowrap}

@media(max-width:840px){
  .grid,.steps,.grid-2,.related .grid{grid-template-columns:1fr}
  .site nav.links{display:none}
  .hero .hero-inner{padding:60px 0 54px}
  .cta-band{padding:30px 22px}
}