/* ===================================
   MODERN PORTFOLIO 2025 - MAHMOUD YOUSIF
   Design System & Core Styles
   =================================== */

/* CSS Custom Properties for Design System */
:root {
  /* Color Palette - Modern Tech Theme */
  --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  --secondary-gradient: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
  --accent-gradient: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
  --success-gradient: linear-gradient(135deg, #43e97b 0%, #38f9d7 100%);

  /* Light Mode Colors */
  --bg-primary: #ffffff;
  --bg-secondary: #f8f9fa;
  --bg-tertiary: #e9ecef;
  --text-primary: #1a202c;
  --text-secondary: #4a5568;
  --text-tertiary: #718096;
  --border-color: rgba(0, 0, 0, 0.1);
  --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07);
  --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.1);
  --shadow-xl: 0 20px 40px rgba(0, 0, 0, 0.15);

  /* Glassmorphism */
  --glass-bg: rgba(255, 255, 255, 0.7);
  --glass-border: rgba(255, 255, 255, 0.3);
  --glass-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);

  /* Accent Colors */
  --accent-primary: #667eea;
  --accent-secondary: #764ba2;
  --accent-success: #43e97b;
  --accent-warning: #f5576c;

  /* Typography */
  --font-primary: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --font-heading: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Courier New', monospace;

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

  /* Border Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.5rem;
  --radius-full: 9999px;

  /* Transitions */
  --transition-fast: 150ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-base: 300ms cubic-bezier(0.4, 0, 0.2, 1);
  --transition-slow: 500ms cubic-bezier(0.4, 0, 0.2, 1);
}

/* Dark Mode Colors */
[data-theme="dark"] {
  --bg-primary: #0f172a;
  --bg-secondary: #1e293b;
  --bg-tertiary: #334155;
  --text-primary: #f8fafc;
  --text-secondary: #cbd5e1;
  --text-tertiary: #94a3b8;
  --border-color: rgba(255, 255, 255, 0.1);
  --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 10px 25px rgba(0, 0, 0, 0.5);
  --shadow-xl: 0 20px 40px rgba(0, 0, 0, 0.6);

  --glass-bg: rgba(30, 41, 59, 0.7);
  --glass-border: rgba(255, 255, 255, 0.1);
  --glass-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
}

/* Reset & Base Styles */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

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

body {
  font-family: var(--font-primary);
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  transition: background-color var(--transition-base), color var(--transition-base);
  overflow-x: hidden;
  margin: 0;
  padding: 0;
  width: 100%;
}

main {
  margin: 0;
  padding: 0;
  width: 100%;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.2;
  margin-bottom: var(--space-md);
}

h1 { font-size: clamp(2.5rem, 5vw, 4rem); }
h2 { font-size: clamp(2rem, 4vw, 3rem); }
h3 { font-size: clamp(1.5rem, 3vw, 2rem); }
h4 { font-size: 1.5rem; }
h5 { font-size: 1.25rem; }
h6 { font-size: 1rem; }

p {
  margin-bottom: var(--space-md);
  color: var(--text-secondary);
}

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

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

/* Utility Classes */
.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-lg);
}

.container-fluid {
  width: 100%;
  padding: 0 var(--space-lg);
}

.section {
  padding: var(--space-3xl) 0;
  position: relative;
}

.text-gradient {
  color: #ffffff !important;
  background: none;
  -webkit-text-fill-color: #ffffff;
  display: inline-block;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-shadow: 0 4px 20px rgba(0, 0, 0, 0.8), 0 2px 10px rgba(0, 0, 0, 0.6);
  font-weight: 900;
  filter: none;
}

/* Glassmorphism Cards */
.glass-card {
  background: var(--glass-bg);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-xl);
  padding: var(--space-xl);
  box-shadow: var(--glass-shadow);
  transition: transform var(--transition-base), box-shadow var(--transition-base);
}

.glass-card:hover {
  transform: translateY(-5px);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.2);
}

/* Modern Buttons */
.btn {
  display: inline-block;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-full);
  font-weight: 600;
  text-align: center;
  transition: all var(--transition-base);
  cursor: pointer;
  border: none;
  font-size: 1rem;
}

.btn-primary {
  background: var(--primary-gradient);
  color: white;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 10px 20px rgba(102, 126, 234, 0.4);
  color: white;
}

.btn-outline {
  background: transparent;
  border: 2px solid var(--accent-primary);
  color: var(--accent-primary);
}

.btn-outline:hover {
  background: var(--accent-primary);
  color: white;
}

.btn-sm {
  padding: 0.5rem 1rem;
  font-size: 0.875rem;
}

/* Mobile Menu Toggle */
.mobile-menu-toggle {
  display: none;
  background: none;
  border: none;
  font-size: 1.5rem;
  color: var(--text-primary);
  cursor: pointer;
}

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

/* Navigation */
.navbar {
  position: fixed;
  top: 0;
  width: 100%;
  background: var(--glass-bg);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--glass-border);
  z-index: 1000;
  transition: all var(--transition-base);
}

.navbar.scrolled {
  box-shadow: var(--shadow-lg);
}

.nav-container {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: var(--space-md) var(--space-lg);
  max-width: 1400px;
  margin: 0 auto;
}

.nav-logo {
  font-size: 1.5rem;
  font-weight: 700;
  background: var(--primary-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

.nav-menu {
  display: flex;
  list-style: none;
  gap: var(--space-xl);
  align-items: center;
}

.nav-link {
  color: var(--text-primary);
  font-weight: 500;
  position: relative;
  padding: 0.5rem 0;
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background: var(--primary-gradient);
  transition: width var(--transition-base);
}

.nav-link:hover::after,
.nav-link.active::after {
  width: 100%;
}

/* Dark Mode Toggle */
.theme-toggle {
  background: var(--bg-tertiary);
  border: none;
  width: 50px;
  height: 28px;
  border-radius: var(--radius-full);
  cursor: pointer;
  position: relative;
  transition: background var(--transition-base);
}

.theme-toggle::before {
  content: '';
  position: absolute;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: white;
  top: 3px;
  left: 3px;
  transition: transform var(--transition-base);
}

[data-theme="dark"] .theme-toggle::before {
  transform: translateX(22px);
}

/* Hero Section */
.hero {
  min-height: 100vh;
  display: flex;
  align-items: center;
  justify-content: center;
  position: relative;
  overflow: hidden;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  padding: 0 var(--space-lg);
}

.hero-content {
  position: relative;
  z-index: 2;
  text-align: center;
  color: white;
  max-width: 900px;
  width: 100%;
  padding: var(--space-2xl);
  margin: 0 auto;
}

.hero-title {
  font-size: clamp(2.5rem, 6vw, 5rem);
  margin-bottom: var(--space-lg);
  animation: fadeInUp 0.8s ease-out;
  text-shadow: 0 4px 20px rgba(0, 0, 0, 0.8), 0 2px 10px rgba(0, 0, 0, 0.6);
  font-weight: 900;
  line-height: 1.1;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.hero-subtitle {
  font-size: clamp(1.2rem, 2.5vw, 1.8rem);
  margin-bottom: var(--space-xl);
  opacity: 1;
  animation: fadeInUp 0.8s ease-out 0.2s backwards;
  text-shadow: 0 4px 20px rgba(0, 0, 0, 0.8), 0 2px 10px rgba(0, 0, 0, 0.6);
  font-weight: 700;
  background: rgba(0, 0, 0, 0.4);
  padding: 0.75rem 1.5rem;
  border-radius: 50px;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  display: inline-block;
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.hero-description {
  font-size: 1.1rem;
  margin-bottom: var(--space-2xl);
  opacity: 1;
  animation: fadeInUp 0.8s ease-out 0.4s backwards;
  text-shadow: 0 4px 20px rgba(0, 0, 0, 0.8), 0 2px 10px rgba(0, 0, 0, 0.6);
  font-weight: 600;
  background: rgba(0, 0, 0, 0.5);
  padding: 1.25rem 2rem;
  border-radius: 15px;
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  max-width: 800px;
  margin-left: auto;
  margin-right: auto;
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.hero-cta {
  display: flex;
  gap: var(--space-md);
  justify-content: center;
  animation: fadeInUp 0.8s ease-out 0.6s backwards;
  flex-wrap: wrap;
}

/* Particle Background */
#particle-canvas {
  position: absolute;
  width: 100%;
  height: 100%;
  top: 0;
  left: 0;
  z-index: 1;
  pointer-events: none;
}

/* Section Titles */
.section-title {
  text-align: center;
  margin-bottom: var(--space-3xl);
}

.section-title h2 {
  font-size: clamp(2rem, 4vw, 3rem);
  margin-bottom: var(--space-md);
}

.section-title .underline {
  width: 80px;
  height: 4px;
  background: var(--primary-gradient);
  margin: 0 auto;
  border-radius: var(--radius-full);
}

/* Experience Cards */
.experience-grid {
  display: grid;
  gap: var(--space-xl);
}

.experience-card {
  background: var(--glass-bg);
  backdrop-filter: blur(10px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-xl);
  padding: var(--space-xl);
  transition: all var(--transition-base);
}

.experience-card:hover {
  transform: translateX(10px);
  box-shadow: var(--shadow-xl);
}

.experience-header {
  display: flex;
  align-items: center;
  gap: var(--space-lg);
  margin-bottom: var(--space-lg);
}

.company-logo {
  width: 60px;
  height: 60px;
  object-fit: contain;
  border-radius: var(--radius-md);
}

.experience-info h3 {
  margin-bottom: var(--space-xs);
  color: var(--text-primary);
}

.job-title {
  color: var(--accent-primary);
  font-weight: 600;
  font-size: 1.1rem;
  margin-bottom: var(--space-xs);
}

.job-duration {
  color: var(--text-tertiary);
  font-size: 0.9rem;
}

.experience-highlights {
  list-style: none;
}

.experience-highlights li {
  padding-left: 1.5rem;
  margin-bottom: var(--space-sm);
  position: relative;
  color: var(--text-secondary);
}

.experience-highlights li::before {
  content: '▹';
  position: absolute;
  left: 0;
  color: var(--accent-primary);
  font-weight: bold;
}

/* Project Cards */
.projects-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
  gap: var(--space-xl);
}

.project-card {
  background: var(--glass-bg);
  backdrop-filter: blur(10px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-xl);
  overflow: hidden;
  transition: all var(--transition-base);
}

.project-card:hover {
  transform: translateY(-10px);
  box-shadow: var(--shadow-xl);
}

.project-image {
  width: 100%;
  height: 200px;
  object-fit: cover;
  transition: transform var(--transition-slow);
}

.project-card:hover .project-image {
  transform: scale(1.05);
}

.project-content {
  padding: var(--space-xl);
}

.project-title {
  margin-bottom: var(--space-sm);
  color: var(--text-primary);
}

.project-description {
  color: var(--text-secondary);
  margin-bottom: var(--space-lg);
  font-size: 0.95rem;
}

.project-tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
  margin-bottom: var(--space-lg);
}

.tag {
  background: var(--bg-tertiary);
  color: var(--accent-primary);
  padding: 0.25rem 0.75rem;
  border-radius: var(--radius-full);
  font-size: 0.85rem;
  font-weight: 500;
}

.project-links {
  display: flex;
  gap: var(--space-md);
}

/* Skills Section */
.skills-container {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--space-xl);
}

.skill-category {
  background: var(--glass-bg);
  backdrop-filter: blur(10px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-xl);
  padding: var(--space-xl);
}

.skill-category h3 {
  margin-bottom: var(--space-lg);
  color: var(--text-primary);
}

.skill-items {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-sm);
}

.skill-item {
  background: var(--primary-gradient);
  color: white;
  padding: 0.5rem 1rem;
  border-radius: var(--radius-full);
  font-size: 0.9rem;
  font-weight: 500;
  transition: transform var(--transition-fast);
}

.skill-item:hover {
  transform: scale(1.05);
}

/* Animations */
@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes float {
  0%, 100% {
    transform: translateY(0);
  }
  50% {
    transform: translateY(-20px);
  }
}

/* Responsive Design */
@media (max-width: 768px) {
  .nav-menu {
    position: fixed;
    top: 70px;
    right: -100%;
    flex-direction: column;
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    width: 70%;
    padding: var(--space-xl);
    border-radius: var(--radius-xl) 0 0 var(--radius-xl);
    transition: right var(--transition-base);
    box-shadow: var(--shadow-xl);
  }

  .nav-menu.active {
    right: 0;
  }

  .hero-cta {
    flex-direction: column;
    align-items: center;
  }

  .hero-content {
    padding: var(--space-lg);
  }

  .hero-title {
    font-size: 2rem;
  }

  .hero-subtitle {
    font-size: 1.2rem;
  }

  .hero-description {
    font-size: 1rem;
  }

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

  .skills-container {
    grid-template-columns: 1fr;
  }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

/* Selection */
::selection {
  background: var(--accent-primary);
  color: white;
}

/* Scrollbar */
::-webkit-scrollbar {
  width: 10px;
}

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

::-webkit-scrollbar-thumb {
  background: var(--accent-primary);
  border-radius: var(--radius-full);
}

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

/* Critical Hero Fix - Override any conflicts */
section#home.hero {
  width: 100vw !important;
  margin: 0 !important;
  padding: 0 1rem !important;
  left: 0 !important;
  right: 0 !important;
  box-sizing: border-box !important;
}

section#home.hero .hero-content {
  max-width: 900px !important;
  width: 100% !important;
  margin: 0 auto !important;
  padding: 2rem !important;
  text-align: center !important;
  box-sizing: border-box !important;
}

/* Statistics Section */
.stats-section {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  padding: 4rem 2rem;
  margin: 0;
}

.stats-grid {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
  max-width: 500px;
  margin: 0 auto;
  padding: 2rem 0;
}

.stat-card {
  text-align: center;
  padding: 2.5rem 1.5rem;
  background: rgba(255, 255, 255, 0.15);
  border-radius: 20px;
  backdrop-filter: blur(15px);
  border: none;
  transition: all var(--transition-base);
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.1);
}

.stat-card:hover {
  transform: translateY(-8px) scale(1.02);
  background: rgba(255, 255, 255, 0.2);
  box-shadow: 0 12px 40px rgba(0, 0, 0, 0.15);
}

.stat-icon {
  font-size: 3.5rem;
  margin-bottom: 1rem;
  display: block;
  filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.2));
}

.stat-number {
  font-size: clamp(2.8rem, 5vw, 4rem);
  font-weight: 900;
  margin-bottom: 0.5rem;
  line-height: 1;
  color: #ffffff;
  text-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
}

.stat-label {
  font-size: 1rem;
  opacity: 0.95;
  font-weight: 600;
  color: #ffffff;
  letter-spacing: 0.5px;
  text-transform: uppercase;
  font-size: 0.85rem;
}

/* Scroll Progress Bar */
.scroll-progress {
  position: fixed;
  top: 0;
  left: 0;
  width: 0%;
  height: 4px;
  background: var(--primary-gradient);
  z-index: 9999;
  transition: width 0.1s ease-out;
}

/* Skills Filtering */
.skill-item {
  cursor: pointer;
  transition: all var(--transition-base);
  position: relative;
}

.skill-item:hover {
  transform: scale(1.08);
  box-shadow: 0 4px 12px rgba(102, 126, 234, 0.3);
}

.skill-item.skill-active {
  background: linear-gradient(135deg, #43e97b 0%, #38f9d7 100%);
  transform: scale(1.1);
  box-shadow: 0 6px 20px rgba(67, 233, 123, 0.4);
}

.project-card.filtered-out {
  opacity: 0;
  transform: scale(0.9);
  transition: all 0.3s ease-out;
}

.skills-reset-btn {
  background: var(--primary-gradient);
  color: white;
  padding: 0.75rem 1.5rem;
  border-radius: var(--radius-full);
  cursor: pointer;
  margin-bottom: var(--space-xl);
  text-align: center;
  font-weight: 600;
  transition: all var(--transition-base);
  display: inline-block;
}

.skills-reset-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 8px 20px rgba(102, 126, 234, 0.4);
}

.skills-reset-btn i {
  margin-right: 0.5rem;
}

/* Mobile Menu Improvements */
@media (max-width: 768px) {
  .mobile-menu-toggle {
    display: block !important;
    z-index: 1001;
  }

  .nav-menu {
    position: fixed;
    top: 70px;
    right: -100%;
    flex-direction: column;
    background: var(--glass-bg);
    backdrop-filter: blur(20px);
    width: 80%;
    max-width: 300px;
    padding: var(--space-2xl) var(--space-xl);
    border-radius: var(--radius-xl) 0 0 var(--radius-xl);
    transition: right var(--transition-base);
    box-shadow: var(--shadow-xl);
    height: calc(100vh - 70px);
    overflow-y: auto;
  }

  .nav-menu.active {
    right: 0;
  }

  .nav-menu li {
    margin: var(--space-md) 0;
  }

  .stats-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}