/* ==========================================================================
   OP Easy Generator — Core Design System & Global Styles
   Futuristic 3D aesthetic with deep navy/charcoal base & glowing accents.
   ========================================================================== */

:root {
  /* Dark Theme Palette (Default) */
  --bg-primary: #060913;
  --bg-secondary: #0b1120;
  --bg-surface: #111a30;
  --bg-surface-translucent: rgba(17, 26, 48, 0.72);
  --bg-card: rgba(19, 29, 56, 0.65);
  --bg-card-hover: rgba(26, 40, 75, 0.85);

  /* Borders & Glows */
  --border-subtle: rgba(255, 255, 255, 0.08);
  --border-bright: rgba(168, 85, 247, 0.35);
  --border-cyan: rgba(6, 182, 212, 0.35);
  --glow-purple: rgba(168, 85, 247, 0.25);
  --glow-cyan: rgba(6, 182, 212, 0.25);
  --glow-blue: rgba(59, 130, 246, 0.25);

  /* Brand Accents */
  --accent-purple: #a855f7;
  --accent-blue: #3b82f6;
  --accent-cyan: #06b6d4;
  --accent-emerald: #10b981;
  --accent-amber: #f59e0b;
  --accent-rose: #f43f5e;

  /* Gradients */
  --gradient-primary: linear-gradient(135deg, #a855f7 0%, #3b82f6 50%, #06b6d4 100%);
  --gradient-glow: radial-gradient(circle, rgba(168, 85, 247, 0.18) 0%, rgba(6, 182, 212, 0.05) 50%, transparent 70%);
  --gradient-card: linear-gradient(145deg, rgba(255, 255, 255, 0.05) 0%, rgba(255, 255, 255, 0.01) 100%);

  /* Typography */
  --text-main: #f8fafc;
  --text-muted: #94a3b8;
  --text-dim: #64748b;
  --font-family: 'Outfit', 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', Consolas, Monaco, monospace;

  /* Shadows */
  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 16px 48px rgba(0, 0, 0, 0.6);
  --shadow-3d: 0 20px 40px -15px rgba(0, 0, 0, 0.7), 0 0 25px rgba(168, 85, 247, 0.15);

  /* Sizing & Transitions */
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-full: 9999px;
  --transition-fast: 0.15s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
}

/* Light Theme Overrides */
[data-theme="light"] {
  --bg-primary: #f8fafc;
  --bg-secondary: #f1f5f9;
  --bg-surface: #ffffff;
  --bg-surface-translucent: rgba(255, 255, 255, 0.82);
  --bg-card: rgba(255, 255, 255, 0.88);
  --bg-card-hover: rgba(255, 255, 255, 0.98);

  --border-subtle: rgba(0, 0, 0, 0.08);
  --border-bright: rgba(147, 51, 234, 0.4);
  --border-cyan: rgba(14, 165, 233, 0.4);
  --glow-purple: rgba(147, 51, 234, 0.15);
  --glow-cyan: rgba(14, 165, 233, 0.15);
  --glow-blue: rgba(37, 99, 235, 0.15);

  --text-main: #0f172a;
  --text-muted: #475569;
  --text-dim: #64748b;

  --shadow-sm: 0 2px 8px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 16px 48px rgba(0, 0, 0, 0.12);
  --shadow-3d: 0 20px 35px -10px rgba(0, 0, 0, 0.12), 0 0 20px rgba(147, 51, 234, 0.1);
}

/* Reset & Box Sizing */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  height: 100%;
}

body {
  font-family: var(--font-family);
  background-color: var(--bg-primary);
  color: var(--text-main);
  line-height: 1.6;
  min-height: 100%;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
  transition: background-color var(--transition-normal), color var(--transition-normal);
  background-image: 
    radial-gradient(at 10% 15%, rgba(168, 85, 247, 0.08) 0px, transparent 50%),
    radial-gradient(at 90% 85%, rgba(6, 182, 212, 0.06) 0px, transparent 50%);
  background-attachment: fixed;
}

/* Typography Styles */
h1, h2, h3, h4, h5, h6 {
  color: var(--text-main);
  font-weight: 700;
  line-height: 1.25;
}

h1 { font-size: 2.75rem; letter-spacing: -0.03em; }
h2 { font-size: 2rem; letter-spacing: -0.02em; }
h3 { font-size: 1.4rem; letter-spacing: -0.01em; }
h4 { font-size: 1.15rem; }

p {
  color: var(--text-muted);
}

a {
  color: var(--accent-cyan);
  text-decoration: none;
  transition: color var(--transition-fast);
}

a:hover {
  color: var(--accent-purple);
}

/* Container */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 1.5rem;
}

/* Sticky Glass Navbar */
.navbar {
  position: sticky;
  top: 0;
  z-index: 1000;
  background: var(--bg-surface-translucent);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border-bottom: 1px solid var(--border-subtle);
  transition: all var(--transition-normal);
}

.navbar .nav-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 4.5rem;
}

.brand-logo {
  display: flex;
  align-items: center;
  gap: 0.75rem;
  font-size: 1.25rem;
  font-weight: 800;
  color: var(--text-main);
  letter-spacing: -0.02em;
}

.brand-logo .logo-icon {
  width: 2.5rem;
  height: 2.5rem;
  border-radius: var(--radius-sm);
  background: var(--gradient-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 0 15px var(--glow-purple);
  color: #fff;
  font-size: 1.25rem;
}

.brand-logo:hover {
  color: var(--text-main);
}

.nav-links {
  display: flex;
  align-items: center;
  gap: 2rem;
  list-style: none;
}

.nav-link {
  color: var(--text-muted);
  font-weight: 500;
  font-size: 0.95rem;
  transition: color var(--transition-fast);
  position: relative;
  padding: 0.5rem 0;
}

.nav-link:hover, .nav-link.active {
  color: var(--text-main);
}

.nav-link.active::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: 2px;
  background: var(--gradient-primary);
  border-radius: var(--radius-full);
}

.nav-actions {
  display: flex;
  align-items: center;
  gap: 1rem;
}

/* Theme Toggle Button */
.theme-toggle-btn {
  background: var(--bg-surface);
  border: 1px solid var(--border-subtle);
  color: var(--text-main);
  width: 2.5rem;
  height: 2.5rem;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.theme-toggle-btn:hover {
  border-color: var(--border-bright);
  box-shadow: 0 0 12px var(--glow-purple);
}

/* Mobile Hamburger */
.mobile-nav-toggle {
  display: none;
  background: transparent;
  border: none;
  color: var(--text-main);
  font-size: 1.5rem;
  cursor: pointer;
  padding: 0.5rem;
}

/* Main Content Area */
main.main-content {
  flex: 1 0 auto;
  padding: 2.5rem 0 4rem;
}

/* Footer */
.footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-subtle);
  padding: 3rem 0 2rem;
  color: var(--text-muted);
  font-size: 0.9rem;
  margin-top: auto;
}

.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr 1fr;
  gap: 2.5rem;
  margin-bottom: 2.5rem;
}

.footer-brand p {
  margin-top: 0.75rem;
  font-size: 0.9rem;
  max-width: 320px;
}

.footer-column h4 {
  font-size: 0.95rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 1rem;
  color: var(--text-main);
}

.footer-links {
  list-style: none;
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
}

.footer-links a {
  color: var(--text-muted);
}

.footer-links a:hover {
  color: var(--text-main);
}

.footer-bottom {
  border-top: 1px solid var(--border-subtle);
  padding-top: 1.5rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 0.85rem;
}

/* Mobile Responsive Adjustments */
@media (max-width: 900px) {
  .footer-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (max-width: 768px) {
  .mobile-nav-toggle {
    display: block;
  }

  .nav-links {
    position: fixed;
    top: 4.5rem;
    left: 0;
    right: 0;
    background: var(--bg-surface);
    flex-direction: column;
    padding: 2rem;
    gap: 1.5rem;
    border-bottom: 1px solid var(--border-subtle);
    box-shadow: var(--shadow-lg);
    display: none;
  }

  .nav-links.open {
    display: flex;
  }

  .footer-grid {
    grid-template-columns: 1fr;
  }

  .footer-bottom {
    flex-direction: column;
    gap: 1rem;
    text-align: center;
  }

  h1 { font-size: 2.15rem; }
  h2 { font-size: 1.65rem; }
}