/* ==========================================================================
   HASSAN NABIL - PERSONAL BRAND DESIGN SYSTEM
   Futuristic AI + Technology + Executive Professional Branding
   ========================================================================== */

:root {
  /* Dark Theme Palette (Default) */
  --bg-primary: #080D1B;
  --bg-surface: #0B1020;
  --bg-surface-elevated: #11182E;
  --bg-glass: rgba(11, 16, 32, 0.75);
  --bg-glass-hover: rgba(17, 24, 46, 0.85);

  --border-subtle: rgba(255, 255, 255, 0.08);
  --border-glow-cyan: rgba(0, 217, 255, 0.35);
  --border-glow-purple: rgba(139, 92, 246, 0.35);

  --accent-blue: #2563EB;
  --accent-cyan: #00D9FF;
  --accent-purple: #8B5CF6;
  --accent-purple-glow: rgba(139, 92, 246, 0.25);
  --accent-cyan-glow: rgba(0, 217, 255, 0.25);

  --text-primary: #FFFFFF;
  --text-secondary: #AAB4C8;
  --text-muted: #64748B;
  --text-accent: #00D9FF;

  --gradient-cyber: linear-gradient(135deg, #00D9FF 0%, #2563EB 50%, #8B5CF6 100%);
  --gradient-surface: linear-gradient(180deg, rgba(17, 24, 46, 0.8) 0%, rgba(11, 16, 32, 0.95) 100%);
  --gradient-glow: radial-gradient(circle at 50% 0%, rgba(0, 217, 255, 0.15) 0%, transparent 70%);

  --shadow-sm: 0 4px 12px rgba(0, 0, 0, 0.25);
  --shadow-md: 0 8px 24px rgba(0, 0, 0, 0.35);
  --shadow-lg: 0 16px 40px rgba(0, 0, 0, 0.5);
  --shadow-cyan-glow: 0 0 25px rgba(0, 217, 255, 0.2);
  --shadow-purple-glow: 0 0 25px rgba(139, 92, 246, 0.2);

  --font-family-base: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Helvetica, Arial, sans-serif;
  --font-family-arabic: 'Tajawal', 'Cairo', 'Segoe UI', Tahoma, Arial, sans-serif;

  --nav-height: 80px;
  --container-max-width: 1240px;
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-full: 9999px;
  --transition-fast: 0.2s ease;
  --transition-normal: 0.3s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-smooth: 0.4s cubic-bezier(0.16, 1, 0.3, 1);
}

/* Light Theme Variables */
[data-theme="light"] {
  --bg-primary: #F4F7FB;
  --bg-surface: #FFFFFF;
  --bg-surface-elevated: #F8FAFC;
  --bg-glass: rgba(255, 255, 255, 0.88);
  --bg-glass-hover: rgba(248, 250, 252, 0.95);

  --border-subtle: rgba(15, 23, 42, 0.1);
  --border-glow-cyan: rgba(2, 132, 199, 0.3);
  --border-glow-purple: rgba(124, 58, 237, 0.3);

  --accent-blue: #1D4ED8;
  --accent-cyan: #0284C7;
  --accent-purple: #7C3AED;
  --accent-purple-glow: rgba(124, 58, 237, 0.15);
  --accent-cyan-glow: rgba(2, 132, 199, 0.15);

  --text-primary: #0F172A;
  --text-secondary: #475569;
  --text-muted: #94A3B8;
  --text-accent: #0284C7;

  --gradient-cyber: linear-gradient(135deg, #0284C7 0%, #1D4ED8 50%, #7C3AED 100%);
  --gradient-surface: linear-gradient(180deg, #FFFFFF 0%, #F8FAFC 100%);
  --gradient-glow: radial-gradient(circle at 50% 0%, rgba(2, 132, 199, 0.1) 0%, transparent 70%);

  --shadow-sm: 0 4px 12px rgba(15, 23, 42, 0.05);
  --shadow-md: 0 8px 24px rgba(15, 23, 42, 0.08);
  --shadow-lg: 0 16px 40px rgba(15, 23, 42, 0.12);
  --shadow-cyan-glow: 0 0 20px rgba(2, 132, 199, 0.15);
  --shadow-purple-glow: 0 0 20px rgba(124, 58, 237, 0.15);
}

/* ==========================================================================
   Base Reset
   ========================================================================== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  scroll-padding-top: calc(var(--nav-height) + 24px);
}

body {
  font-family: var(--font-family-base);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.65;
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
  transition: background-color var(--transition-normal), color var(--transition-normal);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Background Cyber Grid / Ambient Light */
.cyber-background {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  pointer-events: none;
  z-index: -1;
  background-image: 
    radial-gradient(circle at 15% 20%, rgba(0, 217, 255, 0.07) 0%, transparent 40%),
    radial-gradient(circle at 85% 75%, rgba(139, 92, 246, 0.07) 0%, transparent 45%);
}

[data-theme="light"] .cyber-background {
  background-image: 
    radial-gradient(circle at 15% 20%, rgba(2, 132, 199, 0.05) 0%, transparent 40%),
    radial-gradient(circle at 85% 75%, rgba(124, 58, 237, 0.05) 0%, transparent 45%);
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  color: var(--text-primary);
  line-height: 1.25;
  font-weight: 700;
  letter-spacing: -0.02em;
}

h1 {
  font-size: clamp(2.25rem, 5vw, 3.75rem);
}

h2 {
  font-size: clamp(1.85rem, 3.5vw, 2.5rem);
}

h3 {
  font-size: clamp(1.35rem, 2.5vw, 1.75rem);
}

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

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

img {
  max-width: 100%;
  height: auto;
  display: block;
}

button, input, textarea, select {
  font-family: inherit;
  font-size: inherit;
}

/* Layout Utilities */
.container {
  width: 100%;
  max-width: var(--container-max-width);
  margin-left: auto;
  margin-right: auto;
  padding-left: 24px;
  padding-right: 24px;
}

.section {
  padding: 90px 0;
  position: relative;
}

.section-alt {
  background-color: var(--bg-surface);
}

.section-header {
  text-align: center;
  max-width: 780px;
  margin: 0 auto 56px;
}

.section-badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 6px 16px;
  border-radius: var(--radius-full);
  background: rgba(0, 217, 255, 0.08);
  border: 1px solid var(--border-glow-cyan);
  color: var(--accent-cyan);
  font-size: 0.85rem;
  font-weight: 600;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  margin-bottom: 16px;
}

.section-title {
  margin-bottom: 16px;
}

.section-subtitle {
  font-size: 1.125rem;
  color: var(--text-secondary);
}

/* Futuristic Text Gradients & Glows */
.text-gradient {
  background: var(--gradient-cyber);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  display: inline-block;
}

.glow-cyan {
  text-shadow: 0 0 16px rgba(0, 217, 255, 0.4);
}

.glow-purple {
  text-shadow: 0 0 16px rgba(139, 92, 246, 0.4);
}

/* Glassmorphism Card Base */
.glass-panel {
  background: var(--bg-glass);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-normal), border-color var(--transition-normal), box-shadow var(--transition-normal);
}

.glass-panel:hover {
  border-color: var(--border-glow-cyan);
  box-shadow: var(--shadow-cyan-glow);
}

/* Custom Scrollbar */
::-webkit-scrollbar {
  width: 9px;
  height: 9px;
}

::-webkit-scrollbar-track {
  background: var(--bg-primary);
}

::-webkit-scrollbar-thumb {
  background: #1E293B;
  border-radius: var(--radius-full);
  border: 2px solid var(--bg-primary);
}

::-webkit-scrollbar-thumb:hover {
  background: var(--accent-cyan);
}

/* Accessibility: Focus Visible */
a:focus-visible, button:focus-visible, input:focus-visible, textarea:focus-visible {
  outline: 2px solid var(--accent-cyan);
  outline-offset: 3px;
}