:root {
  --brand: #1d4ed8;
  --brand-dark: #1e3a8a;
  --brand-soft: #eaf0ff;
  --accent: #06b6d4;
  --bg: #ffffff;
  --bg-alt: #f4f7fb;
  --ink: #0f172a;
  --muted: #64748b;
  --border: #e2e8f0;
  --radius: 12px;
  --shadow: 0 10px 30px rgba(15, 23, 42, .08);
  --shadow-lg: 0 20px 50px rgba(15, 23, 42, .12);
  --maxw: 1140px;
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.65;
  font-size: 17px;
}

img { max-width: 100%; height: auto; }
a { color: var(--brand); text-decoration: none; }
a:hover { text-decoration: underline; }
h1, h2, h3, h4 { line-height: 1.2; font-weight: 700; letter-spacing: -.01em; }
.container { max-width: var(--maxw); margin: 0 auto; padding: 0 20px; }

.skip-link {
  position: absolute; left: -9999px; top: 0;
  background: var(--ink); color: #fff; padding: 8px 14px; z-index: 100; border-radius: 0 0 8px 0;
}
.skip-link:focus { left: 0; }

/* ---------- Header ---------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: rgba(255, 255, 255, .92);
  backdrop-filter: saturate(180%) blur(8px);
  border-bottom: 1px solid var(--border);
}
.header-inner { display: flex; align-items: center; gap: 18px; min-height: 64px; }

.brand { display: inline-flex; align-items: center; gap: 10px; font-weight: 800; color: var(--ink); font-size: 1.2rem; }
.brand:hover { text-decoration: none; }
.brand-logo {
  display: inline-flex; align-items: center; justify-content: center;
  width: 34px; height: 34px; border-radius: 9px;
  background: linear-gradient(135deg, var(--brand), var(--accent));
  color: #fff; font-size: .8rem; font-weight: 800;
}

.site-nav { display: flex; gap: 4px; margin-left: auto; }
.site-nav a { padding: 8px 12px; border-radius: 8px; color: var(--ink); font-weight: 600; font-size: .95rem; }
.site-nav a:hover { background: var(--brand-soft); color: var(--brand); text-decoration: none; }

.lang-switcher { display: flex; gap: 4px; }
.lang-link {
  padding: 6px 10px; border-radius: 8px; color: var(--muted); font-weight: 600; font-size: .85rem;
  border: 1px solid var(--border);
}
.lang-link:hover { text-decoration: none; border-color: var(--brand); color: var(--brand); }
.lang-link.is-active { background: var(--brand); color: #fff; border-color: var(--brand); }

.nav-toggle, .nav-toggle-label { display: none; }

/* ---------- Hero ---------- */
.hero {
  padding: 84px 0 64px;
  background:
    radial-gradient(900px 400px at 80% -10%, rgba(6, 182, 212, .18), transparent 60%),
    radial-gradient(700px 400px at 10% 0%, rgba(29, 78, 216, .16), transparent 55%),
    var(--bg);
  text-align: center;
}
.hero-title { font-size: clamp(2rem, 5vw, 3.4rem); margin: 0 0 18px; max-width: 20ch; margin-inline: auto; }
.hero-subtitle { font-size: 1.2rem; color: var(--muted); max-width: 62ch; margin: 0 auto 30px; }
.hero-cta { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }

.btn {
  display: inline-block; padding: 13px 26px; border-radius: 999px; font-weight: 700; font-size: 1rem;
  transition: transform .15s ease, box-shadow .15s ease, background .15s ease;
}
.btn:hover { text-decoration: none; transform: translateY(-1px); }
.btn-primary { background: var(--brand); color: #fff; box-shadow: 0 8px 20px rgba(29, 78, 216, .3); }
.btn-primary:hover { background: var(--brand-dark); }
.btn-ghost { background: transparent; color: var(--brand); border: 2px solid var(--brand); }
.btn-ghost:hover { background: var(--brand-soft); }
.btn-light { background: #fff; color: var(--brand-dark); }
.btn-light:hover { background: #eef3ff; }

/* ---------- Stats ---------- */
.stats { background: var(--brand); color: #fff; }
.stats-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; padding: 34px 20px; text-align: center; }
.stat-value { display: block; font-size: 2rem; font-weight: 800; }
.stat-label { color: #cfe0ff; font-size: .95rem; }

/* ---------- Sections ---------- */
.section { padding: 64px 0; }
.section-alt { background: var(--bg-alt); }
.section-title { font-size: 1.9rem; text-align: center; margin: 0 0 38px; }

/* ---------- Features ---------- */
.features-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.feature-card {
  background: var(--bg); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 26px; box-shadow: var(--shadow);
}
.feature-card h3 { margin: 0 0 8px; font-size: 1.15rem; }
.feature-card p { margin: 0; color: var(--muted); }
.feature-icon {
  display: inline-block; width: 14px; height: 14px; border-radius: 50%;
  background: linear-gradient(135deg, var(--brand), var(--accent)); margin-bottom: 14px;
  box-shadow: 0 0 0 6px var(--brand-soft);
}
/* ---------- Steps ---------- */
.steps-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; }
.step { background: var(--bg); border-radius: var(--radius); padding: 26px; border: 1px solid var(--border); }
.step-num {
  display: inline-flex; align-items: center; justify-content: center;
  width: 40px; height: 40px; border-radius: 50%; background: var(--brand); color: #fff;
  font-weight: 800; margin-bottom: 12px;
}
.step h3 { margin: 0 0 8px; }
.step p { margin: 0; color: var(--muted); }

/* ---------- CTA bands ---------- */
.cta-band { background: var(--brand-soft); padding: 56px 20px; text-align: center; }
.cta-band h2 { margin: 0 0 10px; }
.cta-band p { color: var(--muted); max-width: 56ch; margin: 0 auto 22px; }
.cta-final { background: var(--brand-dark); color: #fff; padding: 64px 20px; text-align: center; }
.cta-final h2 { margin: 0 0 10px; }
.cta-final p { color: #cfe0ff; max-width: 56ch; margin: 0 auto 24px; }

/* ---------- Cards / lists ---------- */
.cards-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; margin: 26px 0; }
.card {
  display: flex; flex-direction: column; gap: 8px;
  border: 1px solid var(--border); border-radius: var(--radius); padding: 24px; box-shadow: var(--shadow);
}
.card-title { margin: 0; font-size: 1.15rem; }
.card-title a { color: var(--ink); }
.card-title a:hover { color: var(--brand); }
.card-desc { color: var(--muted); margin: 0; font-size: .98rem; }
.card-categories { margin: 0; display: flex; gap: 6px; flex-wrap: wrap; }
.card-link { font-weight: 700; margin-top: auto; }

/* ---------- Badges ---------- */
.badge {
  display: inline-block; padding: 3px 11px; border-radius: 999px; font-size: .82rem; font-weight: 600;
  background: var(--brand-soft); color: var(--brand);
}
.badge:hover { text-decoration: none; background: var(--brand); color: #fff; }

/* ---------- Page (single) ---------- */
.page { padding: 48px 0 72px; }
.page-header { margin-bottom: 26px; }
.page-title { font-size: clamp(1.7rem, 4vw, 2.6rem); margin: 0 0 10px; }
.page-desc { color: var(--muted); font-size: 1.1rem; margin: 0 0 10px; }
.page-meta { color: var(--muted); font-size: .9rem; margin: 0 0 6px; }
.page-categories { margin: 8px 0 0; display: flex; gap: 6px; align-items: center; flex-wrap: wrap; color: var(--muted); font-size: .92rem; }

.page-content { max-width: 760px; }
.page-content h2 { margin-top: 2em; font-size: 1.55rem; }
.page-content h3 { margin-top: 1.6em; font-size: 1.25rem; }
.page-content p { color: #1e293b; }
.page-content ul, .page-content ol { padding-left: 1.4em; }
.page-content li { margin: 6px 0; }
.page-content blockquote {
  margin: 1.4em 0; padding: 14px 20px; border-left: 4px solid var(--brand);
  background: var(--bg-alt); border-radius: 0 8px 8px 0; color: var(--muted);
}
.page-content code {
  background: var(--bg-alt); border: 1px solid var(--border); border-radius: 6px; padding: 1px 6px; font-size: .9em;
}
.page-content pre { background: #0f172a; color: #e2e8f0; padding: 18px; border-radius: 10px; overflow-x: auto; }
.page-content pre code { background: transparent; border: 0; color: inherit; }
.page-content table { border-collapse: collapse; width: 100%; margin: 1.4em 0; }
.page-content th, .page-content td { border: 1px solid var(--border); padding: 9px 12px; text-align: left; }
.page-content th { background: var(--bg-alt); }
.page-content a { text-decoration: underline; }
/* ---------- TOC ---------- */
.toc {
  background: var(--bg-alt); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 16px 20px; margin-bottom: 24px; max-width: 760px;
}
.toc summary { font-weight: 700; cursor: pointer; color: var(--ink); }
.toc nav ul { margin: 10px 0 0; padding-left: 1.2em; }
.toc li { margin: 4px 0; }
.toc a { color: var(--brand); }

/* ---------- Plans / pricing ---------- */
.plans { display: grid; grid-template-columns: repeat(3, 1fr); gap: 22px; margin: 30px 0; }
.plan {
  display: flex; flex-direction: column; gap: 12px;
  border: 1px solid var(--border); border-radius: var(--radius); padding: 28px; box-shadow: var(--shadow);
}
.plan--featured { border: 2px solid var(--brand); box-shadow: var(--shadow-lg); position: relative; }
.plan--featured::before {
  content: "★"; position: absolute; top: -14px; right: 20px; background: var(--brand); color: #fff;
  width: 30px; height: 30px; border-radius: 50%; display: flex; align-items: center; justify-content: center; font-size: .9rem;
}
.plan-name { margin: 0; font-size: 1.2rem; }
.plan-price { font-size: 2.1rem; font-weight: 800; margin: 0; }
.plan-price span { font-size: 1rem; color: var(--muted); font-weight: 500; }
.plan-features { list-style: none; padding: 0; margin: 4px 0 8px; color: #1e293b; }
.plan-features li { padding: 6px 0 6px 26px; position: relative; border-bottom: 1px dashed var(--border); }
.plan-features li::before { content: "✓"; position: absolute; left: 0; color: var(--brand); font-weight: 800; }
.plan .btn { text-align: center; margin-top: auto; }

/* ---------- FAQ ---------- */
.faq-item {
  border: 1px solid var(--border); border-radius: var(--radius); margin-bottom: 12px; background: var(--bg);
  overflow: hidden;
}
.faq-item summary { cursor: pointer; padding: 16px 20px; font-weight: 700; list-style: none; position: relative; }
.faq-item summary::after { content: "+"; position: absolute; right: 20px; top: 12px; font-size: 1.4rem; color: var(--brand); }
.faq-item[open] summary::after { content: "–"; }
.faq-answer { padding: 0 20px 18px; color: var(--muted); }

/* ---------- Error page ---------- */
.error-page { text-align: center; padding: 90px 20px; }
.error-code { font-size: 5rem; font-weight: 800; color: var(--brand); margin: 0; letter-spacing: .04em; }
.error-page h1 { font-size: 2rem; margin: 0 0 10px; }
.error-page p { color: var(--muted); margin: 0 auto 24px; max-width: 46ch; }

/* ---------- Footer ---------- */
.site-footer { background: #0b1220; color: #cbd5e1; margin-top: 64px; }
.footer-inner { padding: 44px 20px; display: grid; gap: 22px; grid-template-columns: 1.4fr 1fr; align-items: start; }
.footer-brand .brand-logo { background: linear-gradient(135deg, var(--brand), var(--accent)); }
.footer-brand p { color: #94a3b8; max-width: 44ch; margin: 10px 0 0; }
.footer-nav { display: flex; flex-direction: column; gap: 8px; }
.footer-nav a { color: #cbd5e1; font-weight: 600; }
.footer-nav a:hover { color: #fff; }
.footer-legal { grid-column: 1 / -1; color: #64748b; font-size: .88rem; margin: 0; border-top: 1px solid #1e293b; padding-top: 18px; }

/* ---------- Responsive ---------- */
@media (max-width: 900px) {
  .features-grid, .steps-grid, .cards-grid, .plans { grid-template-columns: repeat(2, 1fr); }
}

@media (max-width: 720px) {
  body { font-size: 16px; }
  .features-grid, .steps-grid, .cards-grid, .plans { grid-template-columns: 1fr; }
  .stats-grid { grid-template-columns: 1fr; gap: 14px; }
  .footer-inner { grid-template-columns: 1fr; }

  .nav-toggle-label {
    display: inline-flex; align-items: center; gap: 8px; margin-left: auto;
    cursor: pointer; font-weight: 700; color: var(--ink); font-size: .95rem;
  }
  .nav-toggle-label span {
    display: inline-block; width: 20px; height: 2px; background: var(--ink); position: relative;
  }
  .nav-toggle-label span::before, .nav-toggle-label span::after {
    content: ""; position: absolute; left: 0; width: 20px; height: 2px; background: var(--ink);
  }
  .nav-toggle-label span::before { top: -6px; }
  .nav-toggle-label span::after { top: 6px; }

  .site-nav {
    display: none; flex-direction: column; position: absolute; top: 64px; left: 0; right: 0;
    background: #fff; border-bottom: 1px solid var(--border); padding: 12px 20px; gap: 4px;
  }
  .nav-toggle:checked ~ .site-nav { display: flex; }
  .lang-switcher { margin-left: 0; }
}