/* ===== VARIABLES ===== */
:root {
  --accent: #4F46E5;
  --accent-light: #818CF8;
  --accent-dark: #3730A3;
  --bg: #FAFAFA;
  --bg-dark: #0F0F14;
  --bg-card: #FFFFFF;
  --text: #1A1A2E;
  --text-secondary: #64748B;
  --border: #E2E8F0;
  --radius: 12px;
  --radius-lg: 20px;
  --shadow: 0 1px 3px rgba(0,0,0,0.08), 0 4px 12px rgba(0,0,0,0.04);
  --shadow-lg: 0 4px 24px rgba(0,0,0,0.1);
  --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --container: 1200px;
}

/* ===== RESET ===== */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; scroll-padding-top: 80px; }
body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
}
a { text-decoration: none; color: inherit; }
img { max-width: 100%; display: block; }
button { cursor: pointer; border: none; background: none; font-family: inherit; }
input, textarea, select { font-family: inherit; font-size: inherit; }

/* ===== UTILITIES ===== */
.container {
  max-width: var(--container);
  margin: 0 auto;
  padding: 0 24px;
}
.section__title {
  font-size: clamp(1.75rem, 4vw, 2.5rem);
  font-weight: 800;
  text-align: center;
  margin-bottom: 8px;
  letter-spacing: -0.02em;
}
.section__title--left { text-align: left; }
.section__subtitle {
  text-align: center;
  color: var(--text-secondary);
  font-size: 1.1rem;
  margin-bottom: 48px;
}

/* ===== BUTTONS ===== */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 14px 32px;
  border-radius: var(--radius);
  font-weight: 600;
  font-size: 0.95rem;
  transition: var(--transition);
  letter-spacing: -0.01em;
}
.btn--primary {
  background: var(--accent);
  color: #fff;
}
.btn--primary:hover {
  background: var(--accent-dark);
  transform: translateY(-2px);
  box-shadow: 0 8px 24px rgba(79,70,229,0.3);
}
.btn--outline {
  border: 2px solid var(--border);
  color: var(--text);
}
.btn--outline:hover {
  border-color: var(--accent);
  color: var(--accent);
}
.btn--sm {
  padding: 10px 24px;
  font-size: 0.875rem;
  width: 100%;
}

/* ===== HEADER ===== */
.header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 1000;
  background: rgba(250,250,250,0.85);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border);
  transition: var(--transition);
}
.header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 72px;
}

/* Logo */
.logo {
  font-size: 1.5rem;
  font-weight: 800;
  letter-spacing: -0.03em;
}
.logo__quantum { color: var(--text); }
.logo__x { color: var(--accent); }

/* Nav */
.nav {
  display: flex;
  gap: 32px;
}
.nav__link {
  font-size: 0.9rem;
  font-weight: 500;
  color: var(--text-secondary);
  transition: var(--transition);
  position: relative;
}
.nav__link:hover { color: var(--accent); }
.nav__link::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--accent);
  transition: var(--transition);
}
.nav__link:hover::after { width: 100%; }

/* Header Actions */
.header__actions {
  display: flex;
  align-items: center;
  gap: 16px;
}

/* Language Selector */
.lang-selector { position: relative; }
.lang-selector__btn {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 8px 14px;
  border-radius: 8px;
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text);
  background: var(--bg-card);
  border: 1px solid var(--border);
  transition: var(--transition);
}
.lang-selector__btn:hover {
  border-color: var(--accent);
  color: var(--accent);
}
.lang-selector__dropdown {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  box-shadow: var(--shadow-lg);
  min-width: 160px;
  opacity: 0;
  visibility: hidden;
  transform: translateY(-8px);
  transition: var(--transition);
  z-index: 100;
}
.lang-selector__dropdown.active {
  opacity: 1;
  visibility: visible;
  transform: translateY(0);
}
.lang-option {
  display: block;
  width: 100%;
  padding: 10px 16px;
  text-align: left;
  font-size: 0.875rem;
  color: var(--text);
  transition: var(--transition);
}
.lang-option:hover {
  background: rgba(79,70,229,0.05);
  color: var(--accent);
}
.lang-option:first-child { border-radius: var(--radius) var(--radius) 0 0; }
.lang-option:last-child { border-radius: 0 0 var(--radius) var(--radius); }

/* Hamburger */
.hamburger {
  display: none;
  flex-direction: column;
  gap: 5px;
  padding: 4px;
}
.hamburger span {
  display: block;
  width: 24px;
  height: 2px;
  background: var(--text);
  transition: var(--transition);
}

/* ===== HERO ===== */
.hero {
  padding: 140px 0 80px;
  background: linear-gradient(135deg, var(--bg) 0%, #EEF2FF 100%);
  overflow: hidden;
}
.hero__inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
}
.hero__title {
  font-size: clamp(2.5rem, 6vw, 4rem);
  font-weight: 800;
  line-height: 1.1;
  letter-spacing: -0.03em;
  margin-bottom: 20px;
}
.hero__subtitle {
  font-size: 1.15rem;
  color: var(--text-secondary);
  line-height: 1.7;
  margin-bottom: 32px;
  max-width: 500px;
}
.hero__actions {
  display: flex;
  gap: 16px;
  flex-wrap: wrap;
}
.hero__visual {
  display: flex;
  justify-content: center;
  align-items: center;
}
.hero__image-placeholder {
  position: relative;
  width: 360px;
  height: 360px;
  display: flex;
  align-items: center;
  justify-content: center;
}
.hero__glow {
  position: absolute;
  width: 300px;
  height: 300px;
  background: radial-gradient(circle, rgba(79,70,229,0.15) 0%, transparent 70%);
  border-radius: 50%;
  animation: pulse 4s ease-in-out infinite;
}
.hero__icon {
  width: 200px;
  height: 200px;
  position: relative;
  z-index: 1;
}
@keyframes pulse {
  0%, 100% { transform: scale(1); opacity: 0.6; }
  50% { transform: scale(1.15); opacity: 1; }
}

/* ===== HERO BADGE ===== */
.hero__badge {
  display: inline-block;
  padding: 6px 16px;
  background: rgba(79,70,229,0.1);
  color: var(--accent);
  font-size: 0.85rem;
  font-weight: 600;
  border-radius: 20px;
  margin-bottom: 16px;
}

/* ===== PRODUCT SHOWCASE ===== */
.products {
  padding: 100px 0;
}
.product-showcase {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 60px;
  align-items: center;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 48px;
}
.product-showcase__image {
  display: flex;
  align-items: center;
  justify-content: center;
}
.product-showcase__image svg {
  width: 260px;
  height: 260px;
}
.product-showcase__highlights {
  display: flex;
  flex-direction: column;
  gap: 20px;
  margin-bottom: 32px;
}
.highlight {
  display: flex;
  gap: 14px;
  align-items: flex-start;
}
.highlight__icon {
  font-size: 1.5rem;
  flex-shrink: 0;
  width: 40px;
  text-align: center;
}
.highlight strong {
  display: block;
  font-size: 0.95rem;
  margin-bottom: 2px;
}
.highlight p {
  color: var(--text-secondary);
  font-size: 0.875rem;
  line-height: 1.5;
}
.product-showcase__price {
  display: flex;
  align-items: baseline;
  gap: 12px;
  margin-bottom: 24px;
  padding: 16px 0;
  border-top: 1px solid var(--border);
}
.price__label {
  font-size: 0.875rem;
  color: var(--text-secondary);
}
.price__amount {
  font-size: 2rem;
  font-weight: 800;
  color: var(--accent);
  letter-spacing: -0.02em;
}

/* ===== FEATURES ===== */
.features {
  padding: 100px 0;
  background: linear-gradient(180deg, #F8FAFC 0%, var(--bg) 100%);
}
.features__grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 24px;
}
.feature-card {
  padding: 32px;
  background: var(--bg-card);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  transition: var(--transition);
}
.feature-card:hover {
  border-color: var(--accent-light);
  transform: translateY(-2px);
}
.feature-card__icon {
  width: 48px;
  height: 48px;
  margin-bottom: 16px;
}
.feature-card__icon svg {
  width: 48px;
  height: 48px;
}
.feature-card__title {
  font-size: 1.1rem;
  font-weight: 700;
  margin-bottom: 8px;
}
.feature-card__desc {
  color: var(--text-secondary);
  font-size: 0.9rem;
  line-height: 1.6;
}

/* ===== ABOUT ===== */
.about {
  padding: 100px 0;
}
.about__inner {
  max-width: 800px;
}
.about__text {
  color: var(--text-secondary);
  font-size: 1.05rem;
  line-height: 1.7;
  margin-bottom: 16px;
}
.about__stats {
  display: flex;
  gap: 48px;
  margin-top: 40px;
}
.stat { text-align: center; }
.stat__number {
  display: block;
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--accent);
  letter-spacing: -0.03em;
}
.stat__label {
  font-size: 0.85rem;
  color: var(--text-secondary);
  font-weight: 500;
}

/* ===== CONTACT ===== */
.contact {
  padding: 100px 0;
  background: #F8FAFC;
}
.contact__form {
  max-width: 640px;
  margin: 0 auto;
}
.form__row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 20px;
}
.form__group {
  margin-bottom: 20px;
}
.form__group label {
  display: block;
  font-size: 0.875rem;
  font-weight: 600;
  margin-bottom: 6px;
  color: var(--text);
}
.form__group input,
.form__group textarea,
.form__group select {
  width: 100%;
  padding: 12px 16px;
  border: 1px solid var(--border);
  border-radius: var(--radius);
  background: var(--bg-card);
  color: var(--text);
  transition: var(--transition);
  outline: none;
}
.form__group input:focus,
.form__group textarea:focus,
.form__group select:focus {
  border-color: var(--accent);
  box-shadow: 0 0 0 3px rgba(79,70,229,0.1);
}
.form__group textarea { resize: vertical; }

/* ===== FOOTER ===== */
.footer {
  background: var(--bg-dark);
  color: #94A3B8;
  padding: 48px 0 24px;
}
.footer__inner {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 24px;
}
.footer__brand { text-align: center; }
.footer__brand .logo__quantum { color: #fff; }
.footer__tagline {
  font-size: 0.9rem;
  margin-top: 8px;
}
.footer__links {
  display: flex;
  gap: 32px;
}
.footer__links a {
  font-size: 0.875rem;
  transition: var(--transition);
}
.footer__links a:hover { color: #fff; }
.footer__bottom {
  font-size: 0.8rem;
  padding-top: 24px;
  border-top: 1px solid rgba(255,255,255,0.1);
  width: 100%;
  text-align: center;
}

/* ===== RESPONSIVE ===== */
@media (max-width: 1024px) {
  .product-showcase { grid-template-columns: 1fr; }
  .features__grid { grid-template-columns: repeat(2, 1fr); }
  .hero__inner { grid-template-columns: 1fr; text-align: center; }
  .hero__subtitle { margin: 0 auto 32px; }
  .hero__actions { justify-content: center; }
  .hero__visual { margin-top: 40px; }
}

@media (max-width: 768px) {
  .nav { display: none; }
  .nav.active {
    display: flex;
    flex-direction: column;
    position: absolute;
    top: 72px;
    left: 0;
    right: 0;
    background: var(--bg-card);
    border-bottom: 1px solid var(--border);
    padding: 24px;
    gap: 16px;
    box-shadow: var(--shadow-lg);
  }
  .hamburger { display: flex; }
  .hamburger.active span:nth-child(1) { transform: rotate(45deg) translate(5px, 5px); }
  .hamburger.active span:nth-child(2) { opacity: 0; }
  .hamburger.active span:nth-child(3) { transform: rotate(-45deg) translate(5px, -5px); }

  .product-showcase { padding: 28px; }
  .features__grid { grid-template-columns: 1fr; }
  .form__row { grid-template-columns: 1fr; }
  .about__stats { gap: 24px; }
  .stat__number { font-size: 2rem; }
  .hero__image-placeholder { width: 260px; height: 260px; }
  .footer__links { flex-wrap: wrap; justify-content: center; gap: 16px; }
}

@media (max-width: 480px) {
  .hero { padding: 120px 0 60px; }
  .hero__actions { flex-direction: column; }
  .btn { width: 100%; }
  .about__stats { flex-direction: column; gap: 16px; }
}