/* ЧекХаб — тёмная тема «стекло». Без внешних зависимостей. */
:root {
  color-scheme: dark;
  --bg: #070b14;
  --card: rgba(255, 255, 255, .06);
  --text: #e9f1fc;
  --muted: #9db0cb;
  --line: rgba(255, 255, 255, .12);
  --accent: #6fb3ff;
  --accent-strong: #2f7cf6;
  --accent-dark: #1b5fd0;
  --ok: #3ddc9a;
  --radius: 18px;
  --shadow: 0 18px 44px rgba(0, 0, 0, .45);

  /* стекло (glassmorphism, тёмное) */
  --glass: linear-gradient(160deg, rgba(255, 255, 255, .17), rgba(255, 255, 255, .075));
  --glass-border: rgba(255, 255, 255, .22);
  --glass-blur: blur(18px) saturate(150%);
  --glass-shadow: 0 18px 44px rgba(0, 0, 0, .46), inset 0 1px 0 rgba(255, 255, 255, .22);
  /* плотная панель — для длинного текста, чтобы читалось поверх любых пятен */
  --glass-panel: linear-gradient(160deg, rgba(20, 28, 46, .76), rgba(11, 17, 30, .58));
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; }

body {
  margin: 0;
  font: 16px/1.65 -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  color: var(--text);
  background-color: var(--bg);
  min-height: 100vh;
}

/* фон: картинка на весь экран + тонкая сетка поверх */
body::before {
  content: ""; position: fixed; inset: 0; z-index: -2;
  background: url("bg.webp") center center / cover no-repeat;
}
body::after {
  content: ""; position: fixed; inset: 0; z-index: -1; pointer-events: none;
  background-image:
    linear-gradient(rgba(255, 255, 255, .030) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, .030) 1px, transparent 1px);
  background-size: 64px 64px;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
img, svg { max-width: 100%; }
::selection { background: rgba(111, 179, 255, .35); color: #fff; }
a:focus-visible, .btn:focus-visible, .burger:focus-visible {
  outline: 2px solid rgba(111, 179, 255, .7); outline-offset: 2px; border-radius: 10px;
}

.wrap { width: 100%; max-width: 1080px; margin: 0 auto; padding: 0 20px; }

/* шапка — матовое стекло поверх контента */
.site-header {
  position: sticky; top: 0; z-index: 20;
  background: rgba(10, 15, 26, .74);
  -webkit-backdrop-filter: blur(18px) saturate(160%);
  backdrop-filter: blur(18px) saturate(160%);
  border-bottom: 1px solid rgba(255, 255, 255, .10);
  box-shadow: 0 8px 30px rgba(0, 0, 0, .38);
}
.header-row { display: flex; align-items: center; gap: 18px; min-height: 64px; position: relative; }
.logo { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 18px; color: var(--text); }
.logo:hover { text-decoration: none; }
.logo-mark {
  width: 32px; height: 32px; border-radius: 10px; flex: 0 0 auto;
  background: linear-gradient(135deg, #2f7cf6, #16c2b0);
  display: grid; place-items: center; color: #fff; font-size: 15px; font-weight: 700;
  box-shadow: 0 8px 22px rgba(47, 124, 246, .45), inset 0 1px 0 rgba(255, 255, 255, .45);
}
.nav { display: flex; gap: 20px; margin-left: auto; font-size: 15px; }
.nav a { color: var(--muted); }
.nav a:hover, .nav a[aria-current="page"] { color: var(--text); text-decoration: none; }
.burger { display: none; margin-left: auto; }

/* кнопки */
.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  padding: 11px 20px; border-radius: 12px; border: 1px solid transparent;
  font: inherit; font-weight: 600; cursor: pointer; text-decoration: none;
  transition: background .15s, transform .15s, box-shadow .15s, border-color .15s;
}
.btn:hover { text-decoration: none; }
.btn-primary {
  background: linear-gradient(135deg, #2f7cf6, #14a6d8); color: #fff;
  box-shadow: 0 10px 26px rgba(47, 124, 246, .38), inset 0 1px 0 rgba(255, 255, 255, .34);
}
.btn-primary:hover {
  background: linear-gradient(135deg, #2569d8, #0f93c2);
  transform: translateY(-1px);
  box-shadow: 0 14px 30px rgba(47, 124, 246, .5), inset 0 1px 0 rgba(255, 255, 255, .34);
}
.btn-ghost {
  background: rgba(255, 255, 255, .07); color: var(--text);
  border-color: var(--glass-border);
  -webkit-backdrop-filter: blur(12px) saturate(140%);
  backdrop-filter: blur(12px) saturate(140%);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, .14), 0 6px 18px rgba(0, 0, 0, .30);
}
.btn-ghost:hover { background: rgba(255, 255, 255, .13); border-color: rgba(111, 179, 255, .45); }
.btn-lg { padding: 14px 26px; font-size: 17px; }

/* типографика блоков */
section { padding: 56px 0; }
.section-head { max-width: 720px; margin-bottom: 26px; }
h1 { font-size: 40px; line-height: 1.15; margin: 0 0 16px; letter-spacing: -.5px; }
h2 { font-size: 28px; line-height: 1.25; margin: 0 0 12px; letter-spacing: -.3px; }
h3 { font-size: 19px; margin: 0 0 8px; }
p { margin: 0 0 14px; }
.lead { font-size: 18px; color: var(--muted); }
.muted { color: var(--muted); }
.small { font-size: 14px; }

/* герой */
.hero { padding: 64px 0 48px; }
.hero-grid { display: grid; grid-template-columns: 1.15fr .85fr; gap: 40px; align-items: start; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin: 24px 0 18px; }
.hero-facts { display: flex; flex-wrap: wrap; gap: 8px 22px; color: var(--muted); font-size: 14px; padding: 0; margin: 0; list-style: none; }
.hero-facts li::before { content: "✓"; color: var(--ok); font-weight: 700; margin-right: 6px; }

/* карточка-стекло */
.card {
  background: var(--glass);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius);
  padding: 22px;
  box-shadow: var(--glass-shadow);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
  transition: transform .18s, box-shadow .18s, border-color .18s;
}
.card:hover {
  transform: translateY(-2px);
  border-color: rgba(111, 179, 255, .40);
  box-shadow: 0 26px 58px rgba(0, 0, 0, .52), inset 0 1px 0 rgba(255, 255, 255, .22);
}

.cards { display: grid; gap: 18px; }
.cards-3 { grid-template-columns: repeat(3, 1fr); }
.cards-2 { grid-template-columns: repeat(2, 1fr); }

.step-num {
  width: 32px; height: 32px; border-radius: 50%; display: grid; place-items: center;
  background: rgba(111, 179, 255, .14); color: #9cc8ff; font-weight: 700; margin-bottom: 10px;
  border: 1px solid rgba(111, 179, 255, .32);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, .18), 0 4px 14px rgba(47, 124, 246, .18);
}


/* статьи */
.article-list { display: grid; gap: 14px; }
.article-item {
  display: block; background: var(--glass); border: 1px solid var(--glass-border);
  border-radius: var(--radius); padding: 18px 20px; color: var(--text);
  box-shadow: var(--glass-shadow);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
  transition: transform .18s, box-shadow .18s, border-color .18s;
}
.article-item:hover {
  border-color: rgba(111, 179, 255, .40); text-decoration: none;
  transform: translateY(-2px);
  box-shadow: 0 26px 58px rgba(0, 0, 0, .5), inset 0 1px 0 rgba(255, 255, 255, .22);
}
.article-item h3 { margin-bottom: 4px; }

/* текст статьи — плотнее стекла, чтобы длинный текст легко читался */
.prose {
  background: var(--glass-panel);
  border: 1px solid rgba(255, 255, 255, .14);
  border-radius: var(--radius);
  padding: 32px;
  box-shadow: var(--glass-shadow);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
}
.prose h2 { margin-top: 32px; }
.prose h3 { margin-top: 22px; }
.prose ul, .prose ol { padding-left: 22px; }
.prose li { margin-bottom: 8px; }
.prose table { width: 100%; border-collapse: collapse; margin: 18px 0; font-size: 15px; }
.prose th, .prose td { border: 1px solid rgba(255, 255, 255, .13); padding: 10px 12px; text-align: left; vertical-align: top; }
.prose th { background: rgba(255, 255, 255, .07); }
.prose blockquote {
  margin: 18px 0; padding: 14px 18px; border-left: 3px solid var(--accent);
  background: rgba(255, 255, 255, .06); border-radius: 0 12px 12px 0;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, .10);
}
.prose code {
  background: rgba(255, 255, 255, .10); border: 1px solid rgba(255, 255, 255, .14);
  padding: 2px 6px; border-radius: 7px; font-size: 14px; color: #dbe9ff;
}
.crumbs { font-size: 14px; color: var(--muted); margin: 20px 0 12px; }
.crumbs a { color: var(--muted); }
.note {
  background: rgba(255, 196, 87, .10);
  border: 1px solid rgba(255, 196, 87, .34);
  border-radius: 14px; padding: 14px 18px; font-size: 15px; color: #ffe9bf;
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, .10);
}
.note a { color: #ffd489; }

/* калькулятор */
.calc { display: grid; grid-template-columns: 1fr 1fr; gap: 22px; align-items: start; }
.field { margin-bottom: 14px; }
.field label { display: block; font-size: 14px; color: var(--muted); margin-bottom: 6px; }
.field input, .field select {
  width: 100%; padding: 10px 12px; font: inherit; color: var(--text);
  border: 1px solid rgba(255, 255, 255, .16); border-radius: 12px;
  background: rgba(255, 255, 255, .07);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, .10), 0 4px 14px rgba(0, 0, 0, .25);
  -webkit-backdrop-filter: blur(8px);
  backdrop-filter: blur(8px);
  transition: border-color .15s, box-shadow .15s, background .15s;
}
.field input::placeholder { color: rgba(157, 176, 203, .75); }
.field input:hover, .field select:hover { background: rgba(255, 255, 255, .10); }
.field input:focus, .field select:focus {
  outline: none; border-color: rgba(111, 179, 255, .60); background: rgba(255, 255, 255, .12);
  box-shadow: 0 0 0 4px rgba(111, 179, 255, .20);
}
.field select option { background: #0f1626; color: var(--text); }
.calc-result {
  background: linear-gradient(160deg, rgba(47, 124, 246, .26), rgba(255, 255, 255, .06));
  border: 1px solid rgba(255, 255, 255, .18); border-radius: 16px; padding: 20px;
  box-shadow: var(--glass-shadow);
  -webkit-backdrop-filter: var(--glass-blur);
  backdrop-filter: var(--glass-blur);
}
.calc-price { font-size: 32px; font-weight: 700; letter-spacing: -.5px; color: #fff; }
.calc-actions { display: flex; flex-wrap: wrap; gap: 10px; margin-top: 12px; }


/* cta / футер */
.cta-band {
  position: relative; overflow: hidden;
  background: linear-gradient(135deg, #1b47c8, #0d8f7e);
  color: #fff; border-radius: 22px; padding: 34px;
  box-shadow: 0 26px 60px rgba(20, 70, 190, .40), inset 0 1px 0 rgba(255, 255, 255, .22);
}
.cta-band::after {
  content: ""; position: absolute; inset: 0; pointer-events: none;
  background:
    radial-gradient(28rem 18rem at 88% -30%, rgba(255, 255, 255, .26), transparent 62%),
    radial-gradient(22rem 16rem at -6% 120%, rgba(255, 255, 255, .14), transparent 60%);
}
.cta-band > * { position: relative; }
.cta-band h2 { color: #fff; }
.cta-band .btn-primary {
  background: rgba(255, 255, 255, .96); color: #0a4fbe;
  box-shadow: 0 10px 26px rgba(3, 22, 60, .30), inset 0 1px 0 #fff;
}
.cta-band .btn-primary:hover { background: #fff; color: #08408f; }
.cta-band .btn-ghost {
  background: rgba(255, 255, 255, .14); color: #fff;
  border-color: rgba(255, 255, 255, .55);
  box-shadow: inset 0 1px 0 rgba(255, 255, 255, .28);
  -webkit-backdrop-filter: blur(10px);
  backdrop-filter: blur(10px);
}
.cta-band .btn-ghost:hover { background: rgba(255, 255, 255, .26); border-color: #fff; }
.site-footer {
  border-top: 1px solid rgba(255, 255, 255, .10); padding: 30px 0; color: var(--muted); font-size: 14px;
  background: rgba(8, 12, 22, .62);
  -webkit-backdrop-filter: blur(14px) saturate(140%);
  backdrop-filter: blur(14px) saturate(140%);
}
.footer-row { display: flex; flex-wrap: wrap; gap: 14px 26px; justify-content: space-between; }
.footer-links { display: flex; flex-wrap: wrap; gap: 16px; }

/* адаптив */
@media (max-width: 900px) {
  h1 { font-size: 32px; }
  h2 { font-size: 24px; }
  .hero-grid, .calc, .cards-3, .cards-2 { grid-template-columns: 1fr; }
  .nav {
    display: none; position: absolute; top: 64px; left: -20px; right: -20px;
    flex-direction: column; gap: 0;
    background: rgba(9, 14, 25, .96);
    -webkit-backdrop-filter: blur(18px) saturate(160%);
    backdrop-filter: blur(18px) saturate(160%);
    border-bottom: 1px solid rgba(255, 255, 255, .12);
    box-shadow: 0 18px 40px rgba(0, 0, 0, .55);
    padding: 8px 20px 16px;
  }
  .nav.is-open { display: flex; }
  .nav a { padding: 10px 0; }
  .burger {
    display: inline-flex; align-items: center; justify-content: center;
    width: 40px; height: 40px; border: 1px solid var(--glass-border); border-radius: 12px;
    background: rgba(255, 255, 255, .09); color: var(--text);
    -webkit-backdrop-filter: blur(12px);
    backdrop-filter: blur(12px);
    cursor: pointer; font-size: 18px;
  }
  .prose { padding: 22px; }
}

@media (max-width: 560px) {
  /* на маленьких экранах кнопка в шапке не нужна: CTA есть в контенте */
  .header-row > .btn-primary { display: none; }
  /* fixed-слой с картинкой на телефонах иногда «дёргается» — фиксируем к верху */
  body::before { background-attachment: scroll; background-size: auto 100vh; background-position: center top; }
  body::after { background-size: 48px 48px; }
}

/* Если браузер не умеет размытие (старые Safari/Firefox) — плотный фон без стекла */
@supports not ((backdrop-filter: blur(1px)) or (-webkit-backdrop-filter: blur(1px))) {
  .site-header { background: rgba(10, 15, 26, .98); }
  .card, .article-item { background: rgba(16, 23, 38, .96); }
  .prose { background: #0f1626; }
  .btn-ghost, .burger, .nav { background: #131c2e; }
  .site-footer { background: #0a1020; }
}

/* Для тех, кому анимации мешают */
@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .card, .article-item, .btn { transition: none; }
  .card:hover, .article-item:hover, .btn-primary:hover { transform: none; }
}