/* OK Energo – modern tech design */
@import url('https://fonts.googleapis.com/css2?family=Plus+Jakarta+Sans:wght@400;500;600;700;800&display=swap');

:root {
  --bg-color: #0c1222;
  --bg-mesh: radial-gradient(ellipse 80% 50% at 50% -20%, rgba(13, 148, 136, 0.18), transparent),
    radial-gradient(ellipse 60% 40% at 100% 50%, rgba(6, 182, 212, 0.08), transparent);
  --surface-color: #131c2e;
  --surface-glass: rgba(19, 28, 46, 0.85);
  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --brand-primary: #f8fafc;
  --brand-accent: #2dd4bf;
  --brand-accent-hover: #5eead4;
  --brand-glow: rgba(45, 212, 191, 0.25);
  --border-color: #1e293b;
  --nav-bg: rgba(12, 18, 34, 0.88);
  --font-main: 'Plus Jakarta Sans', 'Segoe UI', system-ui, sans-serif;
  --radius: 12px;
  --radius-lg: 20px;
  --shadow: 0 4px 24px rgba(0, 0, 0, 0.3);
  --shadow-hover: 0 12px 40px rgba(45, 212, 191, 0.15);
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

* { margin: 0; padding: 0; box-sizing: border-box; }

body {
  font-family: var(--font-main);
  background-color: var(--bg-color);
  background-image: var(--bg-mesh);
  background-attachment: fixed;
  color: var(--text-primary);
  line-height: 1.65;
  transition: var(--transition);
}

/* Skip link – přístupnost */
.skip-link {
  position: absolute;
  top: -100px;
  left: 1rem;
  z-index: 10000;
  padding: 0.75rem 1.25rem;
  background: var(--brand-accent);
  color: #fff !important;
  border-radius: var(--radius);
  font-weight: 600;
  transition: top 0.2s ease;
}
.skip-link:focus {
  top: 1rem;
  outline: 3px solid var(--brand-accent-hover);
  outline-offset: 2px;
}

/* Typography */
h1, h2, h3 { color: var(--brand-primary); line-height: 1.2; margin-bottom: 1rem; }
h1 { font-size: clamp(2.5rem, 5vw, 3.75rem); font-weight: 800; letter-spacing: -0.02em; }
h2 { font-size: clamp(1.75rem, 3vw, 2.25rem); font-weight: 700; }
h3 { font-size: 1.25rem; font-weight: 600; }
a { color: var(--brand-accent); text-decoration: none; transition: var(--transition); }
a:hover { color: var(--brand-accent-hover); }

/* Focus – viditelný obrys pro klávesnici */
a:focus-visible,
button:focus-visible,
input:focus-visible,
select:focus-visible,
textarea:focus-visible {
  outline: 2px solid var(--brand-accent);
  outline-offset: 2px;
}

/* Header – glass, větší touch target */
header {
  position: fixed;
  width: 100%;
  top: 0;
  z-index: 1000;
  background: var(--nav-bg);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-color);
}
.nav-container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 1rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
}
.logo {
  font-size: 1.35rem;
  font-weight: 700;
  color: var(--brand-primary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
  letter-spacing: -0.02em;
}
.logo img {
  height: 40px;
  width: auto;
  max-height: 48px;
  object-fit: contain;
  display: block;
}
.logo svg {
  width: 32px;
  height: 32px;
  fill: var(--brand-accent);
  filter: drop-shadow(0 0 8px var(--brand-glow));
}
.nav-links { display: flex; gap: 2rem; align-items: center; }
.nav-links a { color: var(--text-primary); font-weight: 600; font-size: 0.95rem; }
.nav-links a:hover, .nav-links a.active { color: var(--brand-accent); }
.controls { display: flex; gap: 0.5rem; align-items: center; }
.btn-icon {
  width: 44px;
  height: 44px;
  min-width: 44px;
  min-height: 44px;
  display: inline-flex;
  align-items: center;
  justify-content: center;
  background: var(--surface-color);
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  cursor: pointer;
  color: var(--text-primary);
  font-size: 1rem;
  transition: var(--transition);
}
.btn-icon:hover { border-color: var(--brand-accent); color: var(--brand-accent); }

/* Tlačítka */
.btn {
  display: inline-block;
  padding: 0.9rem 1.75rem;
  background: var(--brand-accent);
  color: #fff !important;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 1rem;
  border: none;
  cursor: pointer;
  transition: var(--transition);
  box-shadow: 0 4px 14px var(--brand-glow);
}
.btn:hover {
  background: var(--brand-accent-hover);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px var(--brand-glow);
}
.btn-outline {
  background: transparent;
  border: 2px solid var(--brand-accent);
  color: var(--brand-accent) !important;
  box-shadow: none;
}
.btn-outline:hover { background: rgba(13, 148, 136, 0.08); box-shadow: none; }

/* Main & sections */
main { margin-top: 80px; min-height: calc(100vh - 80px - 320px); }
section { padding: 5rem 2rem; max-width: 1200px; margin: 0 auto; }

/* Úvodní blok na homepage – pozadí hero-bg-01.webp zde */
.home-hero-block {
  position: relative;
  overflow: hidden;
}
.home-hero-block::before {
  content: '';
  position: absolute;
  inset: 0;
  z-index: 0;
  background-image: url('../img/hero-bg-01.webp');
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
}
.home-hero-block::after {
  content: '';
  position: absolute;
  inset: 0;
  z-index: 0;
  background: linear-gradient(180deg, rgba(12, 18, 34, 0.88) 0%, rgba(12, 18, 34, 0.96) 100%);
}
.home-hero-block > * { position: relative; z-index: 1; }
.home-hero-block .bg-light::before { opacity: 0.2; }
.home-hero-block .bg-light {
  background: rgba(19, 28, 46, 0.85);
  border-color: rgba(30, 41, 59, 0.9);
}
.home-hero-block .card {
  background: rgba(19, 28, 46, 0.9);
  border-color: rgba(30, 41, 59, 0.95);
}
.home-hero-block .card--highlight {
  background: linear-gradient(135deg, rgba(45, 212, 191, 0.35), rgba(15, 118, 110, 0.5));
}

/* Hero – na celou šířku; pozadí v .home-hero-block (homepage) a v .hero--sub (podstránky) */
.hero {
  position: relative;
  text-align: center;
  padding: 8rem 2rem 5rem;
  max-width: none;
  width: 100%;
  margin-left: 0;
  margin-right: 0;
  box-sizing: border-box;
}
.hero--sub {
  padding: 6rem 2rem 3rem;
  overflow: hidden;
}
.hero--sub::before {
  content: '';
  position: absolute;
  inset: 0;
  z-index: 0;
  background-image: url('../img/hero-bg-01.webp');
  background-size: cover;
  background-position: center;
  background-repeat: no-repeat;
}
.hero--sub::after {
  content: '';
  position: absolute;
  inset: 0;
  z-index: 0;
  background: linear-gradient(180deg, rgba(12, 18, 34, 0.88) 0%, rgba(12, 18, 34, 0.96) 100%);
}
.hero--sub > * { position: relative; z-index: 1; }
.hero p {
  font-size: 1.2rem;
  color: var(--text-secondary);
  max-width: 720px;
  margin: 0 auto 2rem;
  line-height: 1.7;
}
.hero-btns { display: flex; flex-wrap: wrap; gap: 1rem; justify-content: center; }

/* Steps list (Jak to probíhá) */
.steps-list {
  max-width: 800px;
  margin: 0 auto;
  padding-left: 2rem;
  line-height: 2.4;
  font-size: 1.1rem;
  color: var(--text-secondary);
}
.steps-list li { margin-bottom: 0.25rem; }

/* CTA hero (dolní sekce) */
.hero-cta {
  padding-top: 5rem;
  border-top: 1px solid var(--border-color);
}

/* Light band – volitelně obrázek: assets/img/section-bg.jpg */
.bg-light {
  position: relative;
  background: var(--surface-color);
  max-width: 100%;
  padding: 5rem 2rem;
  border-top: 1px solid var(--border-color);
  border-bottom: 1px solid var(--border-color);
  overflow: hidden;
}
.bg-light::before {
  content: '';
  position: absolute;
  inset: 0;
  z-index: 0;
  background-image: url('../img/section-bg.webp');
  background-size: cover;
  background-position: center;
  opacity: 0.28;
}
.bg-light > * { position: relative; z-index: 1; }

/* Grid & cards – modern glass/card */
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(280px, 1fr)); gap: 2rem; }
.grid-2 { grid-template-columns: 1fr 1fr; }
.card {
  background: var(--surface-color);
  padding: 2rem;
  border-radius: var(--radius-lg);
  border: 1px solid var(--border-color);
  transition: var(--transition);
  box-shadow: var(--shadow);
}
.card:hover {
  transform: translateY(-6px);
  box-shadow: var(--shadow-hover);
  border-color: var(--brand-accent);
}
.card--highlight {
  background: linear-gradient(135deg, var(--brand-accent), #0f766e);
  color: #fff;
  border: none;
  text-align: center;
}
.card--highlight h3 { color: #fff; }
.card--highlight p { color: rgba(255,255,255,0.9); }
.card ul { margin-left: 1.5rem; margin-bottom: 0.5rem; }
.card ul li { margin-bottom: 0.25rem; }
.card--accent { border-color: var(--brand-accent); }

/* Formuláře */
.form-group { margin-bottom: 1.5rem; }
.form-group label { display: block; margin-bottom: 0.5rem; font-weight: 600; font-size: 0.95rem; }
.form-control {
  width: 100%;
  padding: 0.85rem 1rem;
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  background: var(--bg-color);
  color: var(--text-primary);
  font-family: inherit;
  font-size: 1rem;
  transition: var(--transition);
}
.form-control:focus { outline: none; border-color: var(--brand-accent); box-shadow: 0 0 0 3px var(--brand-glow); }
.btn--full { width: 100%; }

/* Realizace */
.badge {
  display: inline-block;
  padding: 0.35rem 0.9rem;
  background: var(--border-color);
  border-radius: 999px;
  font-size: 0.8rem;
  font-weight: 600;
  margin-bottom: 1rem;
  letter-spacing: 0.02em;
}
.badge--accent { background: var(--brand-accent); color: #fff; }

/* FAQ – accordion */
.faq-item {
  border-bottom: 1px solid var(--border-color);
  transition: var(--transition);
}
.faq-item:first-child { border-top: 1px solid var(--border-color); }
.faq-head {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 1rem;
  padding: 1.25rem 0;
  background: none;
  border: none;
  cursor: pointer;
  text-align: left;
  font-family: inherit;
  font-size: 1.1rem;
  font-weight: 600;
  color: var(--brand-accent);
  transition: var(--transition);
}
.faq-head:hover { color: var(--brand-accent-hover); }
.faq-head::after {
  content: '';
  flex-shrink: 0;
  width: 20px;
  height: 20px;
  border-right: 2px solid currentColor;
  border-bottom: 2px solid currentColor;
  transform: rotate(45deg) translateY(-4px);
  transition: transform 0.3s ease;
}
.faq-item.open .faq-head::after { transform: rotate(-135deg) translateY(2px); }
.faq-body {
  max-height: 0;
  overflow: hidden;
  transition: max-height 0.35s ease;
}
.faq-item.open .faq-body { max-height: 280px; }
.faq-body-inner { padding-bottom: 1.25rem; color: var(--text-secondary); line-height: 1.7; }
.faq-item h3 { margin: 0; cursor: pointer; }

/* Služby – průmyslový segment */
.industry-label {
  color: var(--brand-accent);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  font-size: 0.85rem;
}
.industry-block { max-width: 800px; margin: 0 auto; text-align: left; }
.industry-block .btn { margin-top: 0.5rem; }

/* Footer – jednotný */
footer {
  background: var(--surface-color);
  padding: 4rem 2rem 2rem;
  border-top: 1px solid var(--border-color);
}
.footer-grid {
  max-width: 1200px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 2rem;
}
.footer-grid h3 { font-size: 1.1rem; margin-bottom: 0.75rem; }
.footer-grid .logo img { height: 44px; }
.footer-grid p { color: var(--text-secondary); font-size: 0.95rem; margin-bottom: 0.5rem; }
.footer-bottom {
  text-align: center;
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border-color);
  color: var(--text-secondary);
  font-size: 0.9rem;
}

/* Mobile */
.menu-toggle {
  display: none;
  width: 44px;
  height: 44px;
  min-width: 44px;
  min-height: 44px;
  align-items: center;
  justify-content: center;
  background: none;
  border: 1px solid var(--border-color);
  border-radius: var(--radius);
  font-size: 1.35rem;
  color: var(--text-primary);
  cursor: pointer;
  transition: var(--transition);
}
.menu-toggle:hover { border-color: var(--brand-accent); color: var(--brand-accent); }

@media (max-width: 768px) {
  .nav-links {
    display: none;
    position: absolute;
    top: 100%;
    left: 0;
    width: 100%;
    background: var(--surface-color);
    flex-direction: column;
    padding: 1.5rem 2rem;
    border-bottom: 1px solid var(--border-color);
    box-shadow: 0 10px 40px rgba(0,0,0,0.08);
  }
  .nav-links.show { display: flex; }
  .menu-toggle { display: flex; }
  .grid { grid-template-columns: 1fr; }
  .grid-2 { grid-template-columns: 1fr; }
  section { padding: 3rem 1.25rem; }
  .hero { padding: 6rem 1.25rem 4rem; }
  .hero--sub { padding: 5rem 1.25rem 2.5rem; }
}

/* Utilities */
.text-center { text-align: center; }
.mt-2 { margin-top: 2rem; }
.mb-2 { margin-bottom: 2rem; }
.mb-4 { margin-bottom: 4rem; }
.hidden { position: absolute; width: 1px; height: 1px; padding: 0; margin: -1px; overflow: hidden; clip: rect(0,0,0,0); border: 0; }
.honeypot { display: none !important; }