/* ============================================================
   ai-robotik.cz — style.css
   Dark portfolio landing · statický HTML+CSS+JS (Apache)
   ============================================================ */

:root {
  --night-950: #06070B;
  --night-900: #0A0C12;
  --night-800: #11141D;
  --night-700: #1A1E2A;
  --neon-400: #38BDF8;
  --neon-300: #7DD3FC;
  --neon-500: #0EA5E9;
  --text: #E5E7EB;
  --text-dim: #9CA3AF;
  --font-sans: 'Inter', ui-sans-serif, system-ui, sans-serif;
  --font-display: 'Space Grotesk', 'Inter', ui-sans-serif, system-ui, sans-serif;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--font-sans);
  background: var(--night-950);
  color: var(--text);
  -webkit-font-smoothing: antialiased;
  overflow-x: clip;
  line-height: 1.6;
}

img, video { max-width: 100%; display: block; }

a { color: inherit; text-decoration: none; }

::selection { background: rgba(56, 189, 248, 0.35); color: #fff; }

::-webkit-scrollbar { width: 10px; }
::-webkit-scrollbar-track { background: var(--night-950); }
::-webkit-scrollbar-thumb { background: #232838; border-radius: 5px; }
::-webkit-scrollbar-thumb:hover { background: #2f3649; }

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 24px;
}

.center { text-align: center; }

.eyebrow {
  display: inline-block;
  font-family: var(--font-display);
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--neon-400);
  margin-bottom: 16px;
}

.eyebrow.center { display: block; }

.h2 {
  font-family: var(--font-display);
  font-size: clamp(28px, 4vw, 44px);
  font-weight: 600;
  line-height: 1.15;
  letter-spacing: -0.02em;
  color: #fff;
  margin-bottom: 16px;
}

.h2.center { text-align: center; }

.section-sub {
  color: var(--text-dim);
  font-size: 16px;
  max-width: 640px;
  margin-bottom: 48px;
}

.section-sub.center { margin-left: auto; margin-right: auto; }

/* ---------- Buttons ---------- */
.btn-primary, .btn-ghost {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 600;
  padding: 14px 28px;
  border-radius: 12px;
  transition: all 0.2s ease;
  cursor: pointer;
  border: 1px solid transparent;
}

.btn-primary {
  background: linear-gradient(135deg, var(--neon-400), var(--neon-500));
  color: #04121C;
}

.btn-primary:hover { filter: brightness(1.1); transform: translateY(-1px); }

.btn-primary.big { font-size: 17px; padding: 16px 34px; }

.btn-ghost {
  background: transparent;
  color: var(--text);
  border-color: rgba(255, 255, 255, 0.18);
}

.btn-ghost:hover { border-color: rgba(56, 189, 248, 0.5); color: var(--neon-300); }

.arrow { transition: transform 0.2s ease; }
.btn-primary:hover .arrow { transform: translateX(3px); }

/* ============================================================
   LOADING SCREEN
   ============================================================ */
.loader {
  position: fixed;
  inset: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--night-950);
}

.loader-inner { display: flex; flex-direction: column; align-items: center; }

.loader-logo {
  display: flex;
  align-items: center;
  gap: 14px;
  margin-bottom: 32px;
}

.loader-logo-box {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 52px;
  height: 52px;
  border-radius: 14px;
  background: linear-gradient(135deg, var(--neon-400), var(--neon-500));
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 700;
  color: var(--night-950);
}

.loader-logo-text {
  font-family: var(--font-display);
  font-size: 24px;
  font-weight: 600;
  letter-spacing: -0.02em;
  color: #fff;
}

.loader-bar {
  width: 224px;
  height: 3px;
  border-radius: 999px;
  background: rgba(255, 255, 255, 0.1);
  overflow: hidden;
}

.loader-bar-fill {
  height: 100%;
  border-radius: 999px;
  background: linear-gradient(90deg, var(--neon-400), var(--neon-500));
  width: 0%;
  transition: width 0.15s ease-out;
}

.loader-pct {
  margin-top: 16px;
  font-family: ui-monospace, monospace;
  font-size: 12px;
  letter-spacing: 0.2em;
  color: rgba(255, 255, 255, 0.4);
}

/* ============================================================
   NAVBAR
   ============================================================ */
.nav {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 50;
  padding: 16px 0;
  transition: background 0.3s ease, padding 0.3s ease, backdrop-filter 0.3s ease;
}

.nav.is-scrolled {
  background: rgba(6, 7, 11, 0.85);
  backdrop-filter: blur(12px);
  padding: 10px 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.06);
}

.nav-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.nav-brand {
  display: flex;
  align-items: center;
  gap: 10px;
}

.nav-brand-box {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border-radius: 10px;
  background: linear-gradient(135deg, var(--neon-400), var(--neon-500));
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 700;
  color: var(--night-950);
}

.nav-brand-text {
  font-family: var(--font-display);
  font-size: 18px;
  font-weight: 600;
  letter-spacing: -0.02em;
  color: #fff;
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 28px;
}

.nav-links a {
  font-size: 14px;
  font-weight: 500;
  color: rgba(255, 255, 255, 0.75);
  transition: color 0.2s ease;
}

.nav-links a:hover { color: var(--neon-300); }

.nav-links .nav-cta {
  font-family: var(--font-display);
  font-weight: 600;
  padding: 10px 20px;
  border-radius: 10px;
  background: linear-gradient(135deg, var(--neon-400), var(--neon-500));
  color: #04121C;
}

.nav-links .nav-cta:hover { filter: brightness(1.1); color: #04121C; }

.nav-burger {
  display: none;
  flex-direction: column;
  justify-content: center;
  gap: 5px;
  width: 44px;
  height: 44px;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid rgba(255, 255, 255, 0.12);
  border-radius: 10px;
  cursor: pointer;
}

.nav-burger span {
  display: block;
  width: 20px;
  height: 2px;
  margin: 0 auto;
  background: #fff;
  border-radius: 2px;
  transition: transform 0.3s cubic-bezier(0.77, 0, 0.175, 1), opacity 0.2s ease;
}

.nav-burger.open span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
.nav-burger.open span:nth-child(2) { transform: rotate(-45deg) translate(4px, -4px); }

/* ============================================================
   HERO
   ============================================================ */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: flex-end;
  overflow: hidden;
}

.hero-video {
  position: absolute;
  inset: 0;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.hero-overlay {
  position: absolute;
  inset: 0;
  background: linear-gradient(to bottom, rgba(6, 7, 11, 0.55) 0%, rgba(6, 7, 11, 0.35) 50%, rgba(6, 7, 11, 0.88) 100%);
}

.hero-content {
  position: relative;
  z-index: 2;
  padding-bottom: 96px;
  padding-top: 120px;
  max-width: 860px;
}

.hero-eyebrow {
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--neon-300);
  margin-bottom: 24px;
  opacity: 0;
}

.hero-title {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: clamp(40px, 7vw, 84px);
  line-height: 1.05;
  letter-spacing: -0.03em;
  color: #fff;
  margin-bottom: 24px;
}

.hero-line { display: block; }

.hero-accent {
  font-family: 'Instrument Serif', Georgia, serif;
  font-style: italic;
  font-weight: 400;
  background: linear-gradient(120deg, var(--neon-300), var(--neon-400));
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}

.hero-sub {
  max-width: 520px;
  color: rgba(255, 255, 255, 0.8);
  font-size: 16px;
  font-weight: 400;
  margin-bottom: 36px;
}

.hero-cta { display: flex; align-items: center; gap: 16px; flex-wrap: wrap; }

.hero-scroll {
  position: absolute;
  bottom: 32px;
  left: 50%;
  transform: translateX(-50%);
  z-index: 2;
  width: 24px;
  height: 40px;
  border: 2px solid rgba(255, 255, 255, 0.3);
  border-radius: 12px;
}

.hero-scroll span {
  position: absolute;
  top: 7px;
  left: 50%;
  width: 4px;
  height: 8px;
  margin-left: -2px;
  border-radius: 2px;
  background: var(--neon-300);
  animation: scroll-dot 1.8s ease-in-out infinite;
}

@keyframes scroll-dot {
  0% { transform: translateY(0); opacity: 1; }
  70% { transform: translateY(12px); opacity: 0; }
  100% { transform: translateY(0); opacity: 0; }
}

/* ============================================================
   ABOUT
   ============================================================ */
.about {
  background: var(--night-900);
  padding: 100px 0;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
}

.about-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 64px;
  align-items: start;
}

.about-lede {
  font-size: 18px;
  line-height: 1.7;
  color: rgba(255, 255, 255, 0.85);
  margin-bottom: 40px;
}

.about-stats {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}

.stat-num {
  display: block;
  font-family: var(--font-display);
  font-size: 34px;
  font-weight: 700;
  color: var(--neon-400);
  margin-bottom: 6px;
}

.stat-label {
  font-size: 13px;
  color: var(--text-dim);
  line-height: 1.4;
}

/* ============================================================
   SERVICES
   ============================================================ */
.services {
  background: var(--night-950);
  padding: 110px 0;
}

.services-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 24px;
}

.service-card {
  background: var(--night-800);
  border: 1px solid rgba(255, 255, 255, 0.07);
  border-radius: 20px;
  padding: 36px;
  transition: border-color 0.25s ease, transform 0.25s ease, background 0.25s ease;
  position: relative;
  overflow: hidden;
}

.service-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: linear-gradient(90deg, transparent, var(--neon-400), transparent);
  opacity: 0;
  transition: opacity 0.25s ease;
}

.service-card:hover {
  border-color: rgba(56, 189, 248, 0.35);
  transform: translateY(-4px);
  background: var(--night-700);
}

.service-card:hover::before { opacity: 1; }

.service-icon {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 52px;
  height: 52px;
  border-radius: 14px;
  background: rgba(56, 189, 248, 0.1);
  color: var(--neon-400);
  margin-bottom: 20px;
}

.service-icon svg { width: 26px; height: 26px; }

.service-title {
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 600;
  color: #fff;
  margin-bottom: 10px;
}

.service-desc {
  font-size: 15px;
  color: var(--text-dim);
  line-height: 1.65;
}

/* ============================================================
   PROCESS
   ============================================================ */
.process {
  background: var(--night-900);
  padding: 110px 0;
  border-top: 1px solid rgba(255, 255, 255, 0.05);
}

.process-steps {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 24px;
  margin-top: 48px;
}

.step {
  position: relative;
  padding: 28px 24px;
  border-radius: 16px;
  background: var(--night-800);
  border: 1px solid rgba(255, 255, 255, 0.06);
}

.step-num {
  display: block;
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.1em;
  color: var(--neon-400);
  margin-bottom: 14px;
}

.step-title {
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 600;
  color: #fff;
  margin-bottom: 8px;
}

.step-desc {
  font-size: 14px;
  color: var(--text-dim);
  line-height: 1.6;
}

/* ============================================================
   CONTACT
   ============================================================ */
.contact {
  background: var(--night-950);
  padding: 120px 0;
  position: relative;
  overflow: hidden;
}

.contact::before {
  content: '';
  position: absolute;
  top: -200px;
  left: 50%;
  transform: translateX(-50%);
  width: 700px;
  height: 400px;
  background: radial-gradient(ellipse, rgba(56, 189, 248, 0.12), transparent 65%);
  pointer-events: none;
}

.contact-cta {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 16px;
  flex-wrap: wrap;
  margin-top: 8px;
  position: relative;
}

/* ============================================================
   FOOTER
   ============================================================ */
.site-footer {
  background: var(--night-900);
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  padding: 64px 0 0;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 48px;
  padding-bottom: 48px;
}

.footer-note {
  font-size: 14px;
  color: var(--text-dim);
  margin-top: 16px;
  max-width: 340px;
  line-height: 1.6;
}

.footer-head {
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 600;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: #fff;
  margin-bottom: 16px;
}

.footer-grid p { margin-bottom: 8px; }

.footer-grid a { font-size: 14px; color: var(--text-dim); transition: color 0.2s ease; }
.footer-grid a:hover { color: var(--neon-300); }

.footer-bottom {
  border-top: 1px solid rgba(255, 255, 255, 0.06);
  padding: 20px 0;
  font-size: 13px;
  color: rgba(255, 255, 255, 0.4);
}

/* ============================================================
   REVEAL ANIMACE (GSAP nastavuje opacity/transform)
   ============================================================ */
[data-reveal] {
  opacity: 0;
  transform: translateY(28px);
}

[data-reveal].is-visible {
  opacity: 1;
  transform: translateY(0);
}

/* ============================================================
   RESPONSIVE
   ============================================================ */
@media (max-width: 900px) {
  .about-grid { grid-template-columns: 1fr; gap: 40px; }
  .services-grid { grid-template-columns: 1fr; }
  .process-steps { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr; gap: 32px; }
}

@media (max-width: 640px) {
  .nav-links {
    position: fixed;
    top: 72px;
    left: 16px;
    right: 16px;
    flex-direction: column;
    align-items: stretch;
    gap: 4px;
    background: rgba(10, 12, 18, 0.97);
    border: 1px solid rgba(255, 255, 255, 0.1);
    border-radius: 16px;
    padding: 16px;
    opacity: 0;
    pointer-events: none;
    transform: translateY(-8px);
    transition: opacity 0.25s ease, transform 0.25s ease;
  }

  .nav-links.open {
    opacity: 1;
    pointer-events: auto;
    transform: translateY(0);
  }

  .nav-links a { padding: 12px 8px; font-size: 15px; }
  .nav-links .nav-cta { text-align: center; margin-top: 8px; }

  .nav-burger { display: flex; }

  .hero-content { padding-bottom: 88px; }
  .hero-scroll { display: none; }
  .about-stats { grid-template-columns: 1fr; gap: 20px; }
  .process-steps { grid-template-columns: 1fr; }
  .contact { padding: 90px 0; }
}