:root{
  --accent:#3390ec; --accent2:#7c5cff; --ink:#0e1621; --muted:#5b6875;
  --bg:#ffffff; --soft:#f5f8fc; --line:#e7edf5;
}
*{box-sizing:border-box}
html{scroll-behavior:smooth}
body{
  margin:0; color:var(--ink); background:var(--bg);
  font:16px/1.65 -apple-system,BlinkMacSystemFont,"Segoe UI",Roboto,Helvetica,Arial,sans-serif;
}
h1,h2,h3{line-height:1.2; letter-spacing:-0.02em}
a{color:inherit}
.grad{background:linear-gradient(90deg,var(--accent),var(--accent2)); -webkit-background-clip:text; background-clip:text; color:transparent}
.center{text-align:center}
.wrap-narrow{max-width:760px; margin:0 auto}

/* nav */
.nav{
  position:sticky; top:0; z-index:30; display:flex; align-items:center; gap:20px;
  padding:14px 24px; background:rgba(255,255,255,.9); backdrop-filter:blur(10px); border-bottom:1px solid var(--line);
}
.brand{font-weight:800; letter-spacing:-0.02em; text-decoration:none}
.nav-links{display:flex; gap:22px; margin-left:auto; font-size:14.5px}
.nav-links a{text-decoration:none; color:var(--muted)}
.nav-links a:hover{color:var(--ink)}
.nav-cta{text-decoration:none; background:var(--accent); color:#fff; padding:9px 16px; border-radius:10px; font-weight:600; font-size:14px}
.nav-cta:hover{background:#2b7fd4}
@media(max-width:760px){ .nav-links{display:none} .nav-cta{margin-left:auto} }

/* buttons */
.btn-cta{
  display:inline-block; text-decoration:none; background:linear-gradient(90deg,var(--accent),var(--accent2));
  color:#fff; padding:14px 28px; border-radius:12px; font-weight:700; font-size:16px;
  box-shadow:0 8px 24px rgba(51,144,236,.28);
}
.btn-cta:hover{filter:brightness(1.05)}
.btn-cta.big{padding:16px 34px; font-size:17px}
.btn-ghost{display:inline-block; text-decoration:none; padding:14px 22px; border-radius:12px; border:1px solid var(--line); font-weight:600; color:var(--ink)}
.btn-ghost:hover{background:var(--soft)}

/* section rhythm */
section{padding:64px 24px}
section h2{font-size:32px; text-align:center; margin:0 0 12px}
.section-sub{color:var(--muted); max-width:660px; margin:0 auto 40px; text-align:center}
@media(max-width:600px){ section h2{font-size:26px} }

/* hero */
.hero{
  padding:74px 24px 46px; text-align:center;
  background:
    radial-gradient(1200px 500px at 50% -10%, rgba(124,92,255,.12), transparent 60%),
    radial-gradient(900px 400px at 80% 10%, rgba(51,144,236,.12), transparent 60%);
}
.hero-inner{max-width:840px; margin:0 auto}
.badge{display:inline-block; background:var(--soft); border:1px solid var(--line); color:var(--accent); padding:6px 14px; border-radius:999px; font-size:13px; font-weight:600; margin-bottom:22px}
.hero h1{font-size:50px; margin:0 0 18px; text-align:center}
.lead{font-size:19px; color:var(--muted); max-width:680px; margin:0 auto 28px}
.hero-actions{display:flex; gap:12px; justify-content:center; flex-wrap:wrap}
.hero-note{margin-top:16px; color:var(--muted); font-size:14px}
@media(max-width:600px){ .hero h1{font-size:34px} .lead{font-size:17px} }

/* generic mockup (hero) */
.mock{max-width:560px; margin:44px auto 0; background:#fff; border:1px solid var(--line); border-radius:16px; box-shadow:0 24px 60px rgba(14,22,33,.12); overflow:hidden; text-align:left}
.mock-bar{display:flex; gap:6px; padding:12px 16px; background:var(--soft); border-bottom:1px solid var(--line)}
.mock-bar span{width:11px; height:11px; border-radius:50%; background:#d6dee8}
.mock-body{padding:20px 22px}

/* shared mock content */
.m-h1{font-size:21px; font-weight:800; margin-bottom:10px}
.m-h2{font-size:18px; font-weight:800; margin-bottom:8px}
.m-sub{color:var(--muted); font-size:12.5px; margin:-4px 0 10px}
.m-p{margin-bottom:10px}
.m-spoiler{background:#c9ced6; color:transparent; border-radius:4px; padding:0 6px}
.m-list{margin:0 0 12px; padding:0; color:#33475b; list-style:none}
.m-list li{margin:3px 0}
.m-ol{margin:0 0 10px; padding-left:20px; color:#33475b}
.m-ol li{margin:3px 0}
.m-quote{border-left:3px solid var(--accent); padding:4px 0 4px 14px; color:#33475b; font-style:italic; margin-bottom:6px}
.m-media{height:150px; border-radius:12px; background:linear-gradient(120deg,#c9d9f4,#dfd2ff)}
.m-media.sm{height:96px; margin-bottom:10px}
.m-link{color:var(--accent); font-weight:600; margin-top:6px}
.m-check{display:flex; flex-direction:column; gap:4px; color:#33475b; margin-bottom:10px}
.m-check label{font-size:14px}
.m-spoiler-block{background:var(--soft); border:1px solid var(--line); border-radius:8px; padding:8px 10px; color:var(--muted); font-size:14px}
.m-table{width:100%; border-collapse:collapse; margin-bottom:12px; font-size:14px}
.m-table th,.m-table td{border:1px solid var(--line); padding:6px 8px; text-align:left}
.m-table th{background:var(--soft)}
.m-carousel{display:flex; gap:6px; margin-bottom:8px}
.m-carousel span{flex:1; height:90px; border-radius:10px; background:linear-gradient(120deg,#c9d9f4,#dfd2ff)}
.m-carousel span:nth-child(2){background:linear-gradient(120deg,#ffe0c2,#ffd0e0)}
.m-carousel span:nth-child(3){background:linear-gradient(120deg,#c9f4d9,#d0f0ff)}
.m-dots{display:flex; gap:5px; justify-content:center; margin-bottom:8px}
.m-dots i{width:6px; height:6px; border-radius:50%; background:#cfd6df}
.m-dots i.on{background:var(--accent)}

/* about — две колонки: текст слева, пример справа */
.about{background:var(--bg)}
.about-grid{display:grid; grid-template-columns:1.05fr .95fr; gap:48px; align-items:center; max-width:1080px; margin:0 auto}
.about-text h2{text-align:left; margin:0 0 16px}
.about-text p{margin:0 0 16px; font-size:17px}
.about-text .btn-cta{margin-top:6px}
.about-demo .mock{margin:0; max-width:none}
@media(max-width:860px){ .about-grid{grid-template-columns:1fr; gap:30px} .about-demo{max-width:520px} }

/* steps */
.steps{background:var(--soft)}
.steps-row{display:grid; grid-template-columns:repeat(4,1fr); gap:16px; max-width:1000px; margin:0 auto 34px}
@media(max-width:820px){ .steps-row{grid-template-columns:1fr 1fr} }
@media(max-width:480px){ .steps-row{grid-template-columns:1fr} }
.step{background:var(--bg); border:1px solid var(--line); border-radius:16px; padding:24px 20px}
.step-n{width:36px; height:36px; border-radius:50%; background:var(--accent); color:#fff; font-weight:700; display:flex; align-items:center; justify-content:center; margin-bottom:12px}
.step-t{font-weight:700; margin-bottom:6px}
.step-d{color:var(--muted); font-size:14.5px}

/* features */
.features{background:var(--bg)}
.grid{display:grid; grid-template-columns:repeat(3,1fr); gap:16px; max-width:1080px; margin:0 auto; text-align:left}
@media(max-width:860px){ .grid{grid-template-columns:1fr 1fr} }
@media(max-width:560px){ .grid{grid-template-columns:1fr} }
.card{background:var(--bg); border:1px solid var(--line); border-radius:16px; padding:22px; transition:transform .15s, box-shadow .15s}
.card:hover{transform:translateY(-3px); box-shadow:0 12px 30px rgba(14,22,33,.08)}
.card-ico{width:44px; height:44px; border-radius:12px; display:flex; align-items:center; justify-content:center; font-size:20px; background:linear-gradient(135deg,rgba(51,144,236,.14),rgba(124,92,255,.14)); margin-bottom:14px}
.card-t{font-size:17px; margin:0 0 10px}
.card-list{margin:0; padding-left:0; list-style:none}
.card-list li{position:relative; padding-left:24px; margin:7px 0; color:var(--muted); font-size:14.5px}
.card-list li:before{content:"✓"; position:absolute; left:0; color:var(--accent); font-weight:700}

/* examples */
.examples{background:var(--soft)}
.ex-grid{display:grid; grid-template-columns:repeat(4,1fr); gap:20px; max-width:1120px; margin:0 auto}
@media(max-width:900px){ .ex-grid{grid-template-columns:1fr 1fr} }
@media(max-width:520px){ .ex-grid{grid-template-columns:1fr; max-width:340px} }
.phone{margin:0}
.ph-screen{
  background:#fff; border:1px solid var(--line); border-radius:20px; padding:16px;
  box-shadow:0 16px 40px rgba(14,22,33,.10); min-height:280px; text-align:left;
}
.phone figcaption{color:var(--muted); font-size:13.5px; margin-top:12px; text-align:center; padding:0 6px}

/* usecases */
.usecases{background:var(--bg)}
.uc-card{background:var(--bg); border:1px solid var(--line); border-radius:16px; padding:24px}
.uc-ico{font-size:26px; margin-bottom:10px}
.uc-t{font-size:17px; margin:0 0 8px}
.uc-d{color:var(--muted); font-size:14.5px; margin:0}

/* nuances */
.nuances{background:var(--soft)}
.nu-list{display:flex; flex-direction:column; gap:14px}
.nu-item{background:var(--bg); border:1px solid var(--line); border-radius:14px; padding:18px 20px; border-left:4px solid var(--accent)}
.nu-item h3{margin:0 0 6px; font-size:16.5px}
.nu-item p{margin:0; color:var(--muted); font-size:15px}

/* faq */
.faq{background:var(--bg)}
.faq-item{border:1px solid var(--line); border-radius:12px; margin-bottom:10px; overflow:hidden; background:var(--bg)}
.faq-item summary{
  cursor:pointer; list-style:none; padding:16px 44px 16px 18px; font-weight:600; position:relative; font-size:16px;
}
.faq-item summary::-webkit-details-marker{display:none}
.faq-item summary:after{content:"+"; position:absolute; right:18px; top:14px; font-size:22px; color:var(--accent); font-weight:400}
.faq-item[open] summary:after{content:"–"}
.faq-item[open] summary{border-bottom:1px solid var(--line)}
.faq-a{padding:14px 18px; color:var(--muted); font-size:15px}

/* final cta */
.cta-final{text-align:center; background:linear-gradient(135deg,rgba(51,144,236,.08),rgba(124,92,255,.10))}
.cta-final p{color:var(--muted); max-width:520px; margin:0 auto 26px}

/* support */
.support{background:var(--bg)}
.support p{color:var(--muted); margin:0 auto 24px; max-width:560px}
.support-btns{display:flex; gap:12px; justify-content:center; flex-wrap:wrap}
.s-btn{text-decoration:none; border:1px solid var(--line); border-radius:12px; padding:12px 20px; font-weight:600; color:var(--ink)}
.s-btn:hover{background:var(--soft)}
.s-btn.donate{background:var(--accent); border-color:var(--accent); color:#fff}
.s-btn.donate:hover{background:#2b7fd4}

/* footer */
.foot{display:flex; justify-content:space-between; align-items:center; flex-wrap:wrap; gap:12px; max-width:1120px; margin:0 auto; padding:28px 24px; border-top:1px solid var(--line); color:var(--muted); font-size:14px}
.foot-links{display:flex; gap:18px}
.foot-links a{text-decoration:none; color:var(--muted)}
.foot-links a:hover{color:var(--ink)}