/* ============================================
   OPUS Landing Page — Design System
   ============================================ */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800;900&display=swap');

:root {
  --bg-primary: #030712;
  --bg-secondary: #0f172a;
  --bg-tertiary: #1e293b;
  --bg-card: rgba(15, 23, 42, 0.6);
  --bg-card-hover: rgba(15, 23, 42, 0.85);
  --bg-glass: rgba(255, 255, 255, 0.03);
  --border-subtle: rgba(255, 255, 255, 0.06);
  --border-hover: rgba(245, 158, 11, 0.4);
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  --accent-blue: #f59e0b;
  --accent-cyan: #d97706;
  --accent-purple: #ea580c;
  --accent-orange: #f97316;
  --accent-green: #22c55e;
  --accent-red: #ef4444;
  --gradient-primary: linear-gradient(135deg, #f59e0b, #ea580c);
  --gradient-accent: linear-gradient(135deg, #f59e0b, #d97706);
  --gradient-cta: linear-gradient(135deg, #f97316, #ef4444);
  --gradient-hero: linear-gradient(160deg, #030712 0%, #0f172a 40%, #1e150a 70%, #0f172a 100%);
  --shadow-sm: 0 2px 8px rgba(0,0,0,0.2);
  --shadow-md: 0 4px 24px rgba(0,0,0,0.3);
  --shadow-lg: 0 20px 40px rgba(0,0,0,0.4);
  --shadow-glow: 0 0 40px rgba(245, 158, 11, 0.12);
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  --radius-full: 9999px;
  --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
  --font: 'Inter', system-ui, -apple-system, sans-serif;
}

/* Reset */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; font-size: 16px; }
body {
  font-family: var(--font);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}
a { text-decoration: none; color: inherit; }
ul { list-style: none; }
img { max-width: 100%; display: block; }
button { font-family: var(--font); cursor: pointer; border: none; }

/* ============ NAVBAR ============ */
.navbar {
  position: fixed; top: 0; left: 0; right: 0; z-index: 100;
  padding: 1rem 2rem;
  transition: var(--transition);
}
.navbar.scrolled {
  background: rgba(3, 7, 18, 0.85);
  backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-subtle);
  padding: 0.75rem 2rem;
}
.navbar .container {
  max-width: 1200px; margin: 0 auto;
  display: flex; align-items: center; justify-content: space-between;
}
.nav-logo { display: flex; align-items: center; gap: 0.75rem; }
.nav-logo-img {
  width: 40px;
  height: 40px;
  border-radius: var(--radius-sm);
  object-fit: contain;
  background: var(--bg-secondary);
  padding: 4px;
  border: 1px solid var(--border-subtle);
  transition: var(--transition);
}
.nav-logo:hover .nav-logo-img {
  border-color: var(--border-hover);
  box-shadow: 0 0 15px rgba(245, 158, 11, 0.3);
  transform: scale(1.05);
}
.nav-logo-text { font-size: 1.4rem; font-weight: 700; letter-spacing: -0.02em; }
.nav-links { display: flex; gap: 2rem; align-items: center; }
.nav-links a {
  color: var(--text-secondary); font-size: 0.9rem; font-weight: 500;
  transition: var(--transition);
}
.nav-links a:hover { color: var(--text-primary); }
.nav-cta {
  background: var(--gradient-primary); color: white !important;
  padding: 0.6rem 1.5rem; border-radius: var(--radius-full);
  font-weight: 600; font-size: 0.85rem;
  transition: var(--transition);
}
.nav-cta:hover { transform: translateY(-2px); box-shadow: var(--shadow-glow); }
.mobile-toggle { display: none; background: none; color: var(--text-primary); font-size: 1.5rem; }

/* ============ HERO ============ */
.hero {
  min-height: 100vh; display: flex; align-items: center;
  padding: 8rem 2rem 4rem;
  background: var(--gradient-hero);
  position: relative; overflow: hidden;
}
.hero::before {
  content: ''; position: absolute; top: -50%; right: -20%;
  width: 800px; height: 800px; border-radius: 50%;
  background: radial-gradient(circle, rgba(245,158,11,0.08) 0%, transparent 70%);
  animation: float 20s ease-in-out infinite;
}
.hero::after {
  content: ''; position: absolute; bottom: -30%; left: -10%;
  width: 600px; height: 600px; border-radius: 50%;
  background: radial-gradient(circle, rgba(217,119,6,0.06) 0%, transparent 70%);
  animation: float 15s ease-in-out infinite reverse;
}
.hero .container {
  max-width: 1200px; margin: 0 auto; width: 100%;
  display: grid; grid-template-columns: 1fr 1fr; gap: 4rem; align-items: center;
  position: relative; z-index: 1;
}
.hero-badge {
  display: inline-flex; align-items: center; gap: 0.5rem;
  background: rgba(59,130,246,0.1); border: 1px solid rgba(59,130,246,0.2);
  padding: 0.4rem 1rem; border-radius: var(--radius-full);
  font-size: 0.8rem; color: var(--accent-blue); font-weight: 500;
  margin-bottom: 1.5rem;
}
.hero-badge .dot {
  width: 6px; height: 6px; border-radius: 50%;
  background: var(--accent-green);
  animation: pulse 2s ease-in-out infinite;
}
.hero h1 {
  font-size: clamp(2.5rem, 5vw, 3.8rem); font-weight: 800;
  line-height: 1.1; letter-spacing: -0.03em; margin-bottom: 1.5rem;
}
.hero h1 .gradient-text {
  background: var(--gradient-accent);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text;
}
.hero-subtitle {
  font-size: 1.15rem; color: var(--text-secondary);
  line-height: 1.7; margin-bottom: 2rem; max-width: 520px;
}
.hero-actions { display: flex; gap: 1rem; flex-wrap: wrap; }
.btn-primary {
  background: var(--gradient-primary); color: white;
  padding: 0.9rem 2rem; border-radius: var(--radius-full);
  font-weight: 600; font-size: 0.95rem;
  transition: var(--transition); display: inline-flex; align-items: center; gap: 0.5rem;
}
.btn-primary:hover { transform: translateY(-2px); box-shadow: 0 10px 30px rgba(245, 158, 11, 0.3); }
.btn-secondary {
  background: transparent; color: var(--text-primary);
  padding: 0.9rem 2rem; border-radius: var(--radius-full);
  font-weight: 600; font-size: 0.95rem;
  border: 1px solid var(--border-subtle);
  transition: var(--transition); display: inline-flex; align-items: center; gap: 0.5rem;
}
.btn-secondary:hover { border-color: var(--border-hover); background: var(--bg-glass); }
.hero-image {
  position: relative;
  perspective: 1000px;
}
.hero-image img {
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-lg), var(--shadow-glow);
  border: 1px solid var(--border-subtle);
  transform: rotateY(-5deg) rotateX(2deg);
  transition: transform 0.5s ease;
}
.hero-image:hover img { transform: rotateY(0deg) rotateX(0deg); }

/* ============ STATS ============ */
.stats {
  padding: 4rem 2rem;
  border-top: 1px solid var(--border-subtle);
  border-bottom: 1px solid var(--border-subtle);
  background: var(--bg-glass);
}
.stats .container {
  max-width: 1200px; margin: 0 auto;
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 2rem;
  text-align: center;
}
.stat-item h3 {
  font-size: clamp(2rem, 4vw, 2.8rem); font-weight: 800;
  background: var(--gradient-accent);
  -webkit-background-clip: text; -webkit-text-fill-color: transparent;
  background-clip: text;
}
.stat-item p { color: var(--text-muted); font-size: 0.9rem; margin-top: 0.25rem; }

/* ============ SECTION COMMON ============ */
.section { padding: 6rem 2rem; }
.section .container { max-width: 1200px; margin: 0 auto; }
.section-header { text-align: center; max-width: 700px; margin: 0 auto 4rem; }
.section-label {
  display: inline-block; font-size: 0.8rem; font-weight: 600;
  text-transform: uppercase; letter-spacing: 0.1em;
  color: var(--accent-blue); margin-bottom: 1rem;
}
.section-title {
  font-size: clamp(2rem, 3.5vw, 2.8rem); font-weight: 800;
  line-height: 1.15; letter-spacing: -0.02em; margin-bottom: 1rem;
}
.section-subtitle { color: var(--text-secondary); font-size: 1.05rem; line-height: 1.7; }

/* ============ FEATURES ============ */
.features { background: var(--bg-secondary); }
.features-grid {
  display: grid; grid-template-columns: repeat(3, 1fr); gap: 1.5rem;
}
.feature-card {
  background: var(--bg-card); border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg); padding: 2rem;
  transition: var(--transition); position: relative; overflow: hidden;
}
.feature-card::before {
  content: ''; position: absolute; top: 0; left: 0; right: 0; height: 3px;
  background: var(--gradient-primary); opacity: 0; transition: var(--transition);
}
.feature-card:hover {
  transform: translateY(-4px); border-color: var(--border-hover);
  box-shadow: var(--shadow-md), var(--shadow-glow);
}
.feature-card:hover::before { opacity: 1; }
.feature-icon {
  width: 48px; height: 48px; border-radius: var(--radius-md);
  display: flex; align-items: center; justify-content: center;
  font-size: 1.4rem; margin-bottom: 1.25rem;
}
.feature-icon.blue { background: rgba(245,158,11,0.12); color: var(--accent-blue); }
.feature-icon.cyan { background: rgba(217,119,6,0.12); color: var(--accent-cyan); }
.feature-icon.purple { background: rgba(234,88,12,0.12); color: var(--accent-purple); }
.feature-icon.orange { background: rgba(249,115,22,0.12); color: var(--accent-orange); }
.feature-icon.green { background: rgba(34,197,94,0.12); color: var(--accent-green); }
.feature-icon.red { background: rgba(239,68,68,0.12); color: var(--accent-red); }
.feature-card h3 { font-size: 1.15rem; font-weight: 700; margin-bottom: 0.75rem; }
.feature-card p { color: var(--text-secondary); font-size: 0.9rem; line-height: 1.6; }

/* ============ DIFFERENTIALS ============ */
.differentials-grid {
  display: grid; grid-template-columns: repeat(2, 1fr); gap: 1.5rem;
}
.diff-card {
  background: var(--bg-card); border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg); padding: 2rem;
  display: flex; gap: 1.5rem; align-items: flex-start;
  transition: var(--transition);
}
.diff-card:hover {
  transform: translateY(-3px); border-color: var(--border-hover);
  box-shadow: var(--shadow-md);
}
.diff-number {
  width: 40px; height: 40px; min-width: 40px; border-radius: 50%;
  background: var(--gradient-primary);
  display: flex; align-items: center; justify-content: center;
  font-weight: 800; font-size: 0.9rem;
}
.diff-card h3 { font-size: 1.05rem; font-weight: 700; margin-bottom: 0.5rem; }
.diff-card p { color: var(--text-secondary); font-size: 0.88rem; line-height: 1.6; }
.diff-badge {
  display: inline-block; font-size: 0.7rem; font-weight: 600;
  text-transform: uppercase; letter-spacing: 0.05em;
  padding: 0.2rem 0.6rem; border-radius: var(--radius-full);
  background: rgba(34,197,94,0.1); color: var(--accent-green);
  margin-top: 0.5rem;
}

/* ============ PRICING ============ */
.pricing { background: var(--bg-secondary); }
.pricing-grid {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 1.25rem;
  align-items: start;
}
.pricing-card {
  background: var(--bg-card); border: 1px solid var(--border-subtle);
  border-radius: var(--radius-lg); padding: 2rem;
  transition: var(--transition); position: relative;
}
.pricing-card.featured {
  border-color: var(--accent-blue);
  box-shadow: var(--shadow-glow);
  transform: scale(1.03);
}
.pricing-card.featured .pricing-popular {
  position: absolute; top: -12px; left: 50%; transform: translateX(-50%);
  background: var(--gradient-primary); color: white;
  padding: 0.3rem 1rem; border-radius: var(--radius-full);
  font-size: 0.75rem; font-weight: 600; white-space: nowrap;
}
.pricing-card h3 { font-size: 1.15rem; font-weight: 700; margin-bottom: 0.5rem; }
.pricing-card .price {
  font-size: 2.2rem; font-weight: 800; margin: 1rem 0 0.25rem;
}
.pricing-card .price span { font-size: 0.9rem; font-weight: 400; color: var(--text-muted); }
.pricing-card .price-desc { font-size: 0.82rem; color: var(--text-muted); margin-bottom: 1.5rem; }
.pricing-card ul { margin-bottom: 1.5rem; }
.pricing-card li {
  padding: 0.4rem 0; font-size: 0.88rem; color: var(--text-secondary);
  display: flex; align-items: center; gap: 0.5rem;
}
.pricing-card li .check { color: var(--accent-green); font-weight: 700; }
.pricing-btn {
  display: block; width: 100%; text-align: center;
  padding: 0.8rem; border-radius: var(--radius-md); font-weight: 600; font-size: 0.9rem;
  transition: var(--transition);
}
.pricing-btn.primary { background: var(--gradient-primary); color: white; }
.pricing-btn.primary:hover { box-shadow: 0 8px 24px rgba(245, 158, 11, 0.3); transform: translateY(-2px); }
.pricing-btn.outline {
  background: transparent; color: var(--text-primary);
  border: 1px solid var(--border-subtle);
}
.pricing-btn.outline:hover { border-color: var(--border-hover); }

/* ============ FAQ ============ */
.faq-list { max-width: 800px; margin: 0 auto; }
.faq-item {
  border: 1px solid var(--border-subtle); border-radius: var(--radius-md);
  margin-bottom: 0.75rem; overflow: hidden;
  transition: var(--transition);
}
.faq-item.active { border-color: var(--border-hover); }
.faq-question {
  width: 100%; padding: 1.25rem 1.5rem;
  background: var(--bg-card); color: var(--text-primary);
  font-size: 0.95rem; font-weight: 600; text-align: left;
  display: flex; justify-content: space-between; align-items: center;
  transition: var(--transition);
}
.faq-question:hover { background: var(--bg-card-hover); }
.faq-icon { transition: transform 0.3s ease; font-size: 1.2rem; color: var(--text-muted); }
.faq-item.active .faq-icon { transform: rotate(45deg); color: var(--accent-blue); }
.faq-answer {
  max-height: 0; overflow: hidden; transition: max-height 0.4s ease;
  background: var(--bg-card);
}
.faq-answer-inner {
  padding: 0 1.5rem 1.25rem;
  color: var(--text-secondary); font-size: 0.9rem; line-height: 1.7;
}

/* ============ CTA FINAL ============ */
.cta-final {
  padding: 6rem 2rem; text-align: center;
  background: linear-gradient(180deg, var(--bg-primary) 0%, var(--bg-secondary) 100%);
  position: relative; overflow: hidden;
}
.cta-final::before {
  content: ''; position: absolute; top: 50%; left: 50%;
  transform: translate(-50%, -50%);
  width: 600px; height: 600px; border-radius: 50%;
  background: radial-gradient(circle, rgba(245, 158, 11, 0.08) 0%, transparent 60%);
}
.cta-final .container { position: relative; z-index: 1; max-width: 700px; margin: 0 auto; }
.cta-final h2 {
  font-size: clamp(2rem, 4vw, 2.8rem); font-weight: 800;
  margin-bottom: 1rem; letter-spacing: -0.02em;
}
.cta-final p { color: var(--text-secondary); font-size: 1.1rem; margin-bottom: 2rem; }

/* ============ FOOTER ============ */
.footer {
  padding: 3rem 2rem 2rem;
  border-top: 1px solid var(--border-subtle);
  background: var(--bg-primary);
}
.footer .container { max-width: 1200px; margin: 0 auto; }
.footer-grid {
  display: grid; grid-template-columns: 2fr 1fr 1fr 1fr; gap: 3rem;
  margin-bottom: 3rem;
}
.footer-brand p { color: var(--text-muted); font-size: 0.88rem; margin-top: 1rem; line-height: 1.6; }
.footer h4 { font-size: 0.85rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.08em; margin-bottom: 1rem; color: var(--text-secondary); }
.footer ul li { margin-bottom: 0.5rem; }
.footer ul a { color: var(--text-muted); font-size: 0.88rem; transition: var(--transition); }
.footer ul a:hover { color: var(--text-primary); }
.footer-bottom {
  border-top: 1px solid var(--border-subtle); padding-top: 1.5rem;
  display: flex; justify-content: space-between; align-items: center;
}
.footer-bottom p { color: var(--text-muted); font-size: 0.8rem; }

/* ============ ANIMATIONS ============ */
@keyframes float {
  0%, 100% { transform: translate(0, 0); }
  50% { transform: translate(30px, -30px); }
}
@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.4; }
}
@keyframes fadeInUp {
  from { opacity: 0; transform: translateY(30px); }
  to { opacity: 1; transform: translateY(0); }
}
.animate { opacity: 0; transform: translateY(30px); transition: all 0.6s cubic-bezier(0.4, 0, 0.2, 1); }
.animate.visible { opacity: 1; transform: translateY(0); }
.animate-delay-1 { transition-delay: 0.1s; }
.animate-delay-2 { transition-delay: 0.2s; }
.animate-delay-3 { transition-delay: 0.3s; }
.animate-delay-4 { transition-delay: 0.4s; }

/* ============ RESPONSIVE ============ */
@media (max-width: 1024px) {
  .hero .container { grid-template-columns: 1fr; text-align: center; }
  .hero-subtitle { margin: 0 auto 2rem; }
  .hero-actions { justify-content: center; }
  .hero-image { margin-top: 2rem; }
  .hero-image img { transform: none; }
  .features-grid { grid-template-columns: repeat(2, 1fr); }
  .pricing-grid { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 768px) {
  .nav-links { display: none; position: fixed; top: 0; left: 0; right: 0; bottom: 0;
    background: rgba(3,7,18,0.97); backdrop-filter: blur(20px);
    flex-direction: column; justify-content: center; align-items: center; gap: 2rem;
  }
  .nav-links.active { display: flex; }
  .mobile-toggle { display: block; }
  .hero { padding: 7rem 1.5rem 3rem; min-height: auto; }
  .features-grid, .differentials-grid { grid-template-columns: 1fr; }
  .pricing-grid { grid-template-columns: 1fr; }
  .pricing-card.featured { transform: none; }
  .stats .container { grid-template-columns: repeat(2, 1fr); }
  .footer-grid { grid-template-columns: 1fr; gap: 2rem; }
  .footer-bottom { flex-direction: column; gap: 0.5rem; text-align: center; }
  .section { padding: 4rem 1.5rem; }
}