/* ===== BASE STYLES ===== */
/* CSS Variables for consistent theming */
:root {
  /* Colors — monochrome, Vercel-inspired */
  --primary-color: #ffffff;
  --secondary-color: #a1a1a1;
  --accent-color: #0070f3;
  --dark-bg: #000000;
  --darker-bg: #000000;
  --light-bg: #0a0a0a;
  --text-primary: #fafafa;
  --text-secondary: #a1a1a1;
  --text-muted: #666666;
  --glass-bg: rgba(255, 255, 255, 0.04);
  --glass-border: rgba(255, 255, 255, 0.14);
  --shadow-color: rgba(255, 255, 255, 0.12);

  /* Gradients — subtle grayscale, used sparingly */
  --gradient-primary: linear-gradient(135deg, #ffffff 0%, #a1a1a1 100%);
  --gradient-secondary: linear-gradient(135deg, #fafafa 0%, #666666 100%);
  --gradient-accent: linear-gradient(135deg, #0070f3 0%, #0059c1 100%);
  --gradient-bg: linear-gradient(180deg, #000000 0%, #000000 100%);

  /* Typography — Inter stands in for Geist Sans */
  --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', ui-monospace, monospace;
  --font-size-xs: 0.75rem;
  --font-size-sm: 0.875rem;
  --font-size-base: 1rem;
  --font-size-lg: 1.125rem;
  --font-size-xl: 1.25rem;
  --font-size-2xl: 1.5rem;
  --font-size-3xl: 1.875rem;
  --font-size-4xl: 2.25rem;
  --font-size-5xl: 3rem;

  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-2xl: 3rem;
  --spacing-3xl: 4rem;

  /* Border radius — tighter, boxier corners */
  --radius-sm: 4px;
  --radius-md: 6px;
  --radius-lg: 8px;
  --radius-xl: 12px;
  --radius-full: 9999px;

  /* Shadows — flat, low-contrast, no color glow */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.4);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.35);
  --shadow-lg: 0 10px 25px -5px rgba(0, 0, 0, 0.45);
  --shadow-xl: 0 20px 40px -10px rgba(0, 0, 0, 0.5);
  --shadow-glow: 0 0 0 1px var(--shadow-color);

  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.2s ease;
  --transition-slow: 0.4s ease;

  /* Z-index */
  --z-dropdown: 1000;
  --z-sticky: 1020;
  --z-fixed: 1030;
  --z-modal-backdrop: 1040;
  --z-modal: 1050;
  --z-popover: 1060;
  --z-tooltip: 1070;
}

/* Dark theme (default) */
[data-theme="dark"] {
  --primary-color: #ffffff;
  --secondary-color: #a1a1a1;
  --accent-color: #0070f3;
  --dark-bg: #000000;
  --darker-bg: #000000;
  --light-bg: #0a0a0a;
  --text-primary: #fafafa;
  --text-secondary: #a1a1a1;
  --text-muted: #666666;
  --glass-bg: rgba(255, 255, 255, 0.04);
  --glass-border: rgba(255, 255, 255, 0.14);
  --shadow-color: rgba(255, 255, 255, 0.12);
}

/* Light theme */
[data-theme="light"] {
  --primary-color: #000000;
  --secondary-color: #444444;
  --accent-color: #0070f3;
  --dark-bg: #ffffff;
  --darker-bg: #ffffff;
  --light-bg: #fafafa;
  --text-primary: #171717;
  --text-secondary: #666666;
  --text-muted: #999999;
  --glass-bg: rgba(0, 0, 0, 0.03);
  --glass-border: rgba(0, 0, 0, 0.12);
  --shadow-color: rgba(0, 0, 0, 0.1);
}

/* ===== RESET & BASE ===== */
*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  padding: 0;
  font-family: var(--font-primary);
  font-size: var(--font-size-base);
  line-height: 1.6;
  color: var(--text-primary);
  background: var(--gradient-bg);
  background-attachment: fixed;
  overflow-x: hidden;
}

/* ===== UTILITY CLASSES ===== */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-lg);
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-sm);
  padding: var(--spacing-md) var(--spacing-xl);
  font-size: var(--font-size-sm);
  font-weight: 500;
  text-decoration: none;
  border: none;
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-normal);
  position: relative;
  overflow: hidden;
}

.btn::before {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(90deg, transparent, rgba(255, 255, 255, 0.2), transparent);
  transition: left var(--transition-slow);
}

.btn:hover::before {
  left: 100%;
}

.btn-primary {
  background: var(--text-primary);
  color: var(--dark-bg);
  box-shadow: none;
}

.btn-primary:hover {
  transform: translateY(-1px);
  opacity: 0.85;
}

.btn-secondary {
  background: transparent;
  border: 1px solid var(--glass-border);
  color: var(--text-primary);
}

.btn-secondary:hover {
  border-color: var(--text-secondary);
  transform: translateY(-1px);
}

.section {
  padding: var(--spacing-3xl) 0;
}

.section-header {
  text-align: center;
  margin-bottom: var(--spacing-3xl);
}

.section-title {
  font-size: var(--font-size-4xl);
  font-weight: 600;
  letter-spacing: -0.02em;
  margin-bottom: var(--spacing-sm);
  color: var(--text-primary);
}

.section-subtitle {
  font-size: var(--font-size-lg);
  color: var(--text-secondary);
  margin: 0;
}

/* ===== GLASSMORPHISM UTILITY ===== */
.glass {
  background: var(--glass-bg);
  backdrop-filter: blur(20px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
}

/* ===== RESPONSIVE UTILITIES ===== */
@media (max-width: 768px) {
  .container {
    padding: 0 var(--spacing-md);
  }

  .section {
    padding: var(--spacing-2xl) 0;
  }

  .section-title {
    font-size: var(--font-size-3xl);
  }
}

@media (max-width: 480px) {
  .container {
    padding: 0 var(--spacing-sm);
  }

  .section {
    padding: var(--spacing-xl) 0;
  }

  .section-title {
    font-size: var(--font-size-2xl);
  }

  .btn {
    padding: var(--spacing-sm) var(--spacing-lg);
    font-size: var(--font-size-xs);
  }
}