/* ==========================================================================
   JACOB WAMBUA PORTFOLIO - UNIFIED STYLESHEET
   Mobile-first responsive design with enhanced accessibility
   ========================================================================== */

/* ==========================================================================
   CSS CUSTOM PROPERTIES & DESIGN SYSTEM
   ========================================================================== */

:root {
  /* ===== COLOR SYSTEM (WCAG AA Compliant) ===== */
  /* Primary brand colors */
  --color-primary-hue: 210;
  --color-secondary-hue: 230;
  --color-accent-hue: 350;
  
  /* Light mode palette */
  --color-primary: hsl(var(--color-primary-hue), 70%, 45%);
  --color-primary-light: hsl(var(--color-primary-hue), 70%, 55%);
  --color-primary-dark: hsl(var(--color-primary-hue), 70%, 35%);
  
  --color-secondary: hsl(var(--color-secondary-hue), 70%, 45%);
  --color-secondary-light: hsl(var(--color-secondary-hue), 70%, 55%);
  --color-secondary-dark: hsl(var(--color-secondary-hue), 70%, 35%);
  
  --color-accent: hsl(var(--color-accent-hue), 70%, 45%);
  --color-accent-light: hsl(var(--color-accent-hue), 70%, 55%);
  --color-accent-dark: hsl(var(--color-accent-hue), 70%, 35%);
  
  /* Neutral colors */
  --color-white: #ffffff;
  --color-black: #000000;
  --color-gray-50: #f9fafb;
  --color-gray-100: #f3f4f6;
  --color-gray-200: #e5e7eb;
  --color-gray-300: #d1d5db;
  --color-gray-400: #9ca3af;
  --color-gray-500: #6b7280;
  --color-gray-600: #4b5563;
  --color-gray-700: #374151;
  --color-gray-800: #1f2937;
  --color-gray-900: #111827;
  
  /* Semantic colors */
  --color-success: #10b981;
  --color-warning: #f59e0b;
  --color-error: #ef4444;
  --color-info: #3b82f6;
  
  /* Surface colors */
  --color-background: var(--color-gray-50);
  --color-surface: var(--color-white);
  --color-surface-hover: var(--color-gray-100);
  
  /* Text colors with high contrast ratios */
  --color-text-primary: var(--color-gray-900);
  --color-text-secondary: var(--color-gray-700);
  --color-text-muted: var(--color-gray-500);
  --color-text-inverse: var(--color-white);
  
  /* ===== TYPOGRAPHY SYSTEM ===== */
  /* Font families */
  --font-primary: 'Poppins', system-ui, -apple-system, 'Segoe UI', Roboto, sans-serif;
  
  /* Font weights */
  --font-weight-light: 300;
  --font-weight-regular: 400;
  --font-weight-medium: 500;
  --font-weight-semibold: 600;
  --font-weight-bold: 700;
  
  /* Font sizes (mobile-first) */
  --font-size-xs: 0.75rem;     /* 12px */
  --font-size-sm: 0.875rem;    /* 14px */
  --font-size-base: 1rem;      /* 16px */
  --font-size-lg: 1.125rem;    /* 18px */
  --font-size-xl: 1.25rem;     /* 20px */
  --font-size-2xl: 1.5rem;     /* 24px */
  --font-size-3xl: 1.875rem;   /* 30px */
  --font-size-4xl: 2.25rem;    /* 36px */
  --font-size-5xl: 3rem;       /* 48px */
  --font-size-6xl: 3.75rem;    /* 60px */
  
  /* Line heights */
  --line-height-tight: 1.25;
  --line-height-normal: 1.5;
  --line-height-relaxed: 1.75;
  
  /* Letter spacing */
  --letter-spacing-tight: -0.025em;
  --letter-spacing-normal: 0;
  --letter-spacing-wide: 0.025em;
  
  /* ===== SPACING SYSTEM ===== */
  --space-1: 0.25rem;   /* 4px */
  --space-2: 0.5rem;    /* 8px */
  --space-3: 0.75rem;   /* 12px */
  --space-4: 1rem;      /* 16px */
  --space-5: 1.25rem;   /* 20px */
  --space-6: 1.5rem;    /* 24px */
  --space-8: 2rem;      /* 32px */
  --space-10: 2.5rem;   /* 40px */
  --space-12: 3rem;     /* 48px */
  --space-16: 4rem;     /* 64px */
  --space-20: 5rem;     /* 80px */
  --space-24: 6rem;     /* 96px */
  --space-32: 8rem;     /* 128px */
  
  /* ===== BORDER RADIUS ===== */
  --radius-none: 0;
  --radius-sm: 0.25rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-2xl: 1.5rem;
  --radius-full: 9999px;
  
  /* ===== SHADOWS ===== */
  --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1), 0 1px 2px rgba(0, 0, 0, 0.06);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.07), 0 2px 4px rgba(0, 0, 0, 0.06);
  --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1), 0 4px 6px rgba(0, 0, 0, 0.05);
  --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.1), 0 10px 10px rgba(0, 0, 0, 0.05);
  --shadow-2xl: 0 25px 50px rgba(0, 0, 0, 0.15);
  
  /* ===== 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);
  
  /* ===== GRADIENTS ===== */
  --gradient-primary: linear-gradient(135deg, var(--color-secondary), var(--color-accent));
  --gradient-secondary: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
  
  /* ===== GLASS EFFECT ===== */
  --glass-background: rgba(255, 255, 255, 0.8);
  --glass-border: rgba(255, 255, 255, 0.2);
  --glass-blur: blur(12px);
  
  /* ===== Z-INDEX SCALE ===== */
  --z-dropdown: 1000;
  --z-sticky: 1020;
  --z-fixed: 1030;
  --z-modal-backdrop: 1040;
  --z-modal: 1050;
  --z-popover: 1060;
  --z-tooltip: 1070;
}

/* ===== DARK MODE COLORS ===== */
.dark-mode {
  /* Adjusted colors for dark mode with proper contrast */
  --color-primary: hsl(var(--color-primary-hue), 60%, 60%);
  --color-primary-light: hsl(var(--color-primary-hue), 60%, 70%);
  --color-primary-dark: hsl(var(--color-primary-hue), 60%, 50%);
  
  --color-secondary: hsl(var(--color-secondary-hue), 60%, 60%);
  --color-secondary-light: hsl(var(--color-secondary-hue), 60%, 70%);
  --color-secondary-dark: hsl(var(--color-secondary-hue), 60%, 50%);
  
  --color-accent: hsl(var(--color-accent-hue), 60%, 60%);
  --color-accent-light: hsl(var(--color-accent-hue), 60%, 70%);
  --color-accent-dark: hsl(var(--color-accent-hue), 60%, 50%);
  
  /* Dark surface colors */
  --color-background: var(--color-gray-900);
  --color-surface: var(--color-gray-800);
  --color-surface-hover: var(--color-gray-700);
  
  /* Dark text colors */
  --color-text-primary: var(--color-gray-100);
  --color-text-secondary: var(--color-gray-300);
  --color-text-muted: var(--color-gray-400);
  --color-text-inverse: var(--color-gray-900);
  
  /* Dark glass effect */
  --glass-background: rgba(31, 41, 55, 0.8);
  --glass-border: rgba(255, 255, 255, 0.1);
  
  /* Dark shadows */
  --shadow-xs: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.4), 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.4), 0 2px 4px rgba(0, 0, 0, 0.3);
  --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.4), 0 4px 6px rgba(0, 0, 0, 0.3);
  --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.4), 0 10px 10px rgba(0, 0, 0, 0.3);
  --shadow-2xl: 0 25px 50px rgba(0, 0, 0, 0.5);
}

/* ==========================================================================
   RESET & BASE STYLES
   ========================================================================== */

*,
*::before,
*::after {
  box-sizing: border-box;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  scroll-padding-top: var(--space-20);
}

body {
  margin: 0;
  font-family: var(--font-primary);
  font-size: var(--font-size-base);
  line-height: var(--line-height-normal);
  color: var(--color-text-primary);
  background-color: var(--color-background);
  transition: color var(--transition-base), background-color var(--transition-base);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* ==========================================================================
   TYPOGRAPHY
   ========================================================================== */

h1, h2, h3, h4, h5, h6 {
  margin: 0 0 var(--space-4) 0;
  font-weight: var(--font-weight-bold);
  letter-spacing: var(--letter-spacing-tight);
  line-height: var(--line-height-tight);
  color: var(--color-text-primary);
}

h1 {
  font-size: clamp(var(--font-size-3xl), 5vw, var(--font-size-5xl));
}

h2 {
  font-size: clamp(var(--font-size-2xl), 4vw, var(--font-size-4xl));
}

h3 {
  font-size: clamp(var(--font-size-xl), 3vw, var(--font-size-2xl));
}

h4 {
  font-size: var(--font-size-lg);
}

h5 {
  font-size: var(--font-size-base);
}

h6 {
  font-size: var(--font-size-sm);
}

p {
  margin: 0 0 var(--space-4) 0;
  line-height: var(--line-height-relaxed);
  color: var(--color-text-secondary);
}

.lead {
  font-size: var(--font-size-lg);
  font-weight: var(--font-weight-medium);
  color: var(--color-text-primary);
}

.text-gradient {
  background: var(--gradient-primary);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  color: transparent;
  display: inline-block;
}

/* ==========================================================================
   NAVIGATION
   ========================================================================== */

.navbar {
  background: var(--glass-background);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border-bottom: 1px solid var(--glass-border);
  padding: var(--space-4) 0;
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: var(--z-fixed);
  transition: all var(--transition-base);
}

.navbar-brand {
  font-weight: var(--font-weight-bold);
  font-size: var(--font-size-xl);
  color: var(--color-primary) !important;
  text-decoration: none;
  letter-spacing: var(--letter-spacing-tight);
}

.nav-link {
  color: var(--color-text-primary) !important;
  font-weight: var(--font-weight-medium);
  padding: var(--space-2) var(--space-4) !important;
  border-radius: var(--radius-md);
  transition: all var(--transition-base);
  position: relative;
  text-decoration: none;
}

.nav-link:hover,
.nav-link:focus {
  color: var(--color-primary) !important;
  background-color: var(--color-surface-hover);
  transform: translateY(-1px);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  width: 0;
  height: 2px;
  background: var(--gradient-primary);
  border-radius: var(--radius-full);
  transition: all var(--transition-base);
  transform: translateX(-50%);
}

.nav-link:hover::after {
  width: 80%;
}

/* Mobile navigation */
@media (max-width: 991.98px) {
  .navbar-collapse {
    background: var(--color-surface);
    border-radius: var(--radius-lg);
    margin-top: var(--space-4);
    padding: var(--space-4);
    box-shadow: var(--shadow-lg);
  }
  
  .nav-link {
    padding: var(--space-3) var(--space-4) !important;
    margin-bottom: var(--space-2);
  }
}

/* ==========================================================================
   BUTTONS
   ========================================================================== */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  font-weight: var(--font-weight-medium);
  line-height: 1;
  border: none;
  border-radius: var(--radius-md);
  text-decoration: none;
  cursor: pointer;
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
  padding: var(--space-3) var(--space-6);
  font-size: var(--font-size-base);
}

.btn:focus {
  outline: 3px solid var(--color-primary);
  outline-offset: 2px;
}

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

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: var(--shadow-lg);
  color: var(--color-white);
}

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

.btn-outline-primary:hover {
  background: var(--color-primary);
  color: var(--color-white);
  transform: translateY(-2px);
}

.btn-lg {
  padding: var(--space-4) var(--space-8);
  font-size: var(--font-size-lg);
  border-radius: var(--radius-lg);
}

.btn-sm {
  padding: var(--space-2) var(--space-4);
  font-size: var(--font-size-sm);
}

/* Button hover effect */
.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%;
}

/* ==========================================================================
   HERO SECTION
   ========================================================================== */

.hero {
  background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
  color: var(--color-white);
  padding: var(--space-32) 0 var(--space-24);
  position: relative;
  overflow: hidden;
  min-height: 100vh;
  display: flex;
  align-items: center;
}

.hero::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: url('../images/bg.webp') no-repeat center center;
  background-size: cover;
  opacity: 0.15;
  z-index: 0;
}

.hero .container {
  position: relative;
  z-index: 1;
}

.hero-image {
  position: relative;
  z-index: 2;
  animation: float 6s ease-in-out infinite;
}

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

.hero-shape {
  position: absolute;
  bottom: -10%;
  right: -10%;
  width: 40%;
  height: 40%;
  background: var(--color-secondary);
  border-radius: 50%;
  opacity: 0.1;
  animation: pulse 8s infinite alternate;
}

@keyframes pulse {
  0% { transform: scale(1); opacity: 0.1; }
  100% { transform: scale(1.3); opacity: 0.15; }
}

/* Mobile hero adjustments */
@media (max-width: 768px) {
  .hero {
    padding: var(--space-24) 0 var(--space-16);
    text-align: center;
  }
  
  .hero-shape {
    width: 60%;
    height: 60%;
  }
}

/* ==========================================================================
   CARDS
   ========================================================================== */

.card {
  background: var(--color-surface);
  border: none;
  border-radius: var(--radius-xl);
  box-shadow: var(--shadow-sm);
  transition: all var(--transition-base);
  overflow: hidden;
  height: 100%;
  display: flex;
  flex-direction: column;
}

.card:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-xl);
}

.card-img-top {
  height: 200px;
  object-fit: cover;
  transition: transform var(--transition-slow);
}

.card:hover .card-img-top {
  transform: scale(1.05);
}

.card-body {
  padding: var(--space-6);
  flex: 1;
  display: flex;
  flex-direction: column;
}

.card-title {
  color: var(--color-text-primary);
  font-weight: var(--font-weight-semibold);
  margin-bottom: var(--space-3);
  font-size: var(--font-size-lg);
}

.card-text {
  color: var(--color-text-secondary);
  flex: 1;
  margin-bottom: var(--space-4);
}

/* Service cards */
.service-card {
  background: var(--glass-background);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
}

/* Project cards */
.project-card {
  position: relative;
}

.project-card .card-body {
  position: relative;
  z-index: 2;
}

/* ==========================================================================
   SKILLS SECTION
   ========================================================================== */

.skill-item {
  text-align: center;
  padding: var(--space-6);
  border-radius: var(--radius-lg);
  background: var(--color-surface);
  box-shadow: var(--shadow-sm);
  transition: transform var(--transition-base);
  height: 100%;
}

.skill-item:hover {
  transform: translateY(-5px);
}

.skill-icon {
  font-size: var(--font-size-4xl);
  color: var(--color-primary);
  margin-bottom: var(--space-4);
  transition: all var(--transition-base);
}

.skill-item:hover .skill-icon {
  transform: scale(1.2) rotate(5deg);
  color: var(--color-accent);
}

.skill-name {
  font-weight: var(--font-weight-semibold);
  color: var(--color-text-primary);
  margin-bottom: var(--space-3);
}

.skill-bar {
  height: 8px;
  background: var(--color-gray-200);
  border-radius: var(--radius-full);
  overflow: hidden;
  margin-bottom: var(--space-2);
}

.dark-mode .skill-bar {
  background: var(--color-gray-700);
}

.skill-progress {
  height: 100%;
  background: var(--gradient-primary);
  border-radius: var(--radius-full);
  position: relative;
  overflow: hidden;
  transition: width 1s ease-out;
}

.skill-progress::after {
  content: '';
  position: absolute;
  top: 0;
  left: -100%;
  width: 100%;
  height: 100%;
  background: linear-gradient(
    90deg,
    transparent,
    rgba(255, 255, 255, 0.4),
    transparent
  );
  animation: shimmer 2s infinite;
}

@keyframes shimmer {
  0% { left: -100%; }
  100% { left: 100%; }
}

/* ==========================================================================
   PROJECTS SECTION
   ========================================================================== */

.projects {
  background: var(--color-gray-50);
  padding: var(--space-24) 0;
}

.dark-mode .projects {
  background: var(--color-gray-800);
}

.filter-btn {
  background: var(--color-surface);
  color: var(--color-text-primary);
  border: 2px solid var(--color-gray-300);
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-full);
  margin: 0 var(--space-2) var(--space-2) 0;
  font-weight: var(--font-weight-medium);
  transition: all var(--transition-base);
}

.filter-btn:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  transform: translateY(-2px);
}

.filter-btn.active {
  background: var(--color-primary);
  color: var(--color-white);
  border-color: var(--color-primary);
}

.dark-mode .filter-btn {
  background: var(--color-surface);
  border-color: var(--color-gray-600);
}

/* ==========================================================================
   FORMS
   ========================================================================== */

.form-control {
  width: 100%;
  padding: var(--space-3) var(--space-4);
  border: 2px solid var(--color-gray-300);
  border-radius: var(--radius-md);
  background: var(--color-surface);
  color: var(--color-text-primary);
  font-size: var(--font-size-base);
  transition: all var(--transition-base);
}

.form-control:focus {
  outline: none;
  border-color: var(--color-primary);
  box-shadow: 0 0 0 3px rgba(59, 130, 246, 0.1);
}

.form-label {
  display: block;
  margin-bottom: var(--space-2);
  font-weight: var(--font-weight-medium);
  color: var(--color-text-primary);
}

.dark-mode .form-control {
  background: var(--color-surface);
  border-color: var(--color-gray-600);
}

.dark-mode .form-control::placeholder {
  color: var(--color-text-muted);
}

/* ==========================================================================
   TESTIMONIALS
   ========================================================================== */

.testimonial-item {
  background: var(--glass-background);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-xl);
  padding: var(--space-8);
  text-align: center;
  box-shadow: var(--shadow-md);
  transition: transform var(--transition-base);
  height: 100%;
}

.testimonial-item:hover {
  transform: translateY(-5px);
}

.testimonial-text {
  font-style: italic;
  font-size: var(--font-size-lg);
  line-height: var(--line-height-relaxed);
  color: var(--color-text-secondary);
  position: relative;
  margin-bottom: var(--space-6);
}

.testimonial-text::before,
.testimonial-text::after {
  content: '"';
  font-size: var(--font-size-3xl);
  color: var(--color-primary);
  opacity: 0.5;
  position: absolute;
  font-family: Georgia, serif;
}

.testimonial-text::before {
  left: -10px;
  top: -10px;
}

.testimonial-text::after {
  right: -10px;
  bottom: -20px;
}

.testimonial-author {
  font-weight: var(--font-weight-semibold);
  color: var(--color-primary);
  font-size: var(--font-size-base);
}

/* ==========================================================================
   DARK MODE TOGGLE
   ========================================================================== */

.dark-mode-toggle {
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: transparent;
  border: 2px solid var(--color-primary);
  color: var(--color-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-base);
  position: relative;
  overflow: hidden;
}

.dark-mode-toggle:hover {
  background: var(--color-primary);
  color: var(--color-white);
  transform: rotate(180deg);
}

.dark-mode-toggle:focus {
  outline: 3px solid var(--color-primary);
  outline-offset: 2px;
}

.dark-mode .dark-mode-toggle {
  background: var(--color-primary);
  color: var(--color-white);
}

.dark-mode .dark-mode-toggle:hover {
  background: transparent;
  color: var(--color-primary);
  transform: rotate(-180deg);
}

/* ==========================================================================
   FOOTER
   ========================================================================== */

footer {
  background: var(--color-gray-900);
  color: var(--color-gray-300);
  padding: var(--space-16) 0;
  position: relative;
  overflow: hidden;
}

footer::before {
  content: '';
  position: absolute;
  top: -50%;
  left: -20%;
  width: 70%;
  height: 200%;
  background: var(--color-primary);
  border-radius: 50%;
  opacity: 0.05;
  transform: rotate(-15deg);
}

.social-icons {
  display: flex;
  gap: var(--space-4);
  justify-content: center;
  margin-top: var(--space-6);
  flex-wrap: wrap;
}

.social-icons a {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.1);
  color: var(--color-gray-300);
  text-decoration: none;
  transition: all var(--transition-base);
  font-size: var(--font-size-lg);
}

.social-icons a:hover {
  transform: translateY(-5px) rotate(8deg);
  background: var(--color-primary);
  color: var(--color-white);
}

/* ==========================================================================
   UTILITY CLASSES
   ========================================================================== */

.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }

.d-none { display: none; }
.d-block { display: block; }
.d-inline { display: inline; }
.d-inline-block { display: inline-block; }
.d-flex { display: flex; }

.align-items-center { align-items: center; }
.justify-content-center { justify-content: center; }
.justify-content-between { justify-content: space-between; }

.mb-4 { margin-bottom: var(--space-4); }
.mb-5 { margin-bottom: var(--space-5); }
.mt-4 { margin-top: var(--space-4); }
.mt-5 { margin-top: var(--space-5); }

.py-5 { padding: var(--space-12) 0; }
.bg-light { background-color: var(--color-gray-50); }

.dark-mode .bg-light {
  background-color: var(--color-gray-800);
}

/* ==========================================================================
   RESPONSIVE GRID SYSTEM
   ========================================================================== */

.container {
  width: 100%;
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--space-4);
}

.row {
  display: flex;
  flex-wrap: wrap;
  margin: 0 calc(-1 * var(--space-3));
}

.col, [class*="col-"] {
  padding: 0 var(--space-3);
  margin-bottom: var(--space-6);
  flex: 1;
}

/* Mobile-first responsive columns */
@media (min-width: 576px) {
  .col-sm-6 { flex: 0 0 50%; max-width: 50%; }
}

@media (min-width: 768px) {
  .container { padding: 0 var(--space-6); }
  .col-md-3 { flex: 0 0 25%; max-width: 25%; }
  .col-md-4 { flex: 0 0 33.333333%; max-width: 33.333333%; }
  .col-md-6 { flex: 0 0 50%; max-width: 50%; }
  .col-md-8 { flex: 0 0 66.666667%; max-width: 66.666667%; }
}

@media (min-width: 992px) {
  .col-lg-6 { flex: 0 0 50%; max-width: 50%; }
}

/* ==========================================================================
   ACCESSIBILITY IMPROVEMENTS
   ========================================================================== */

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}

.skip-link {
  position: absolute;
  top: -40px;
  left: var(--space-4);
  background: var(--color-primary);
  color: var(--color-white);
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-md);
  text-decoration: none;
  z-index: var(--z-tooltip);
  transition: top var(--transition-base);
}

.skip-link:focus {
  top: var(--space-4);
}

/* Focus styles for better accessibility */
*:focus {
  outline: 3px solid var(--color-primary);
  outline-offset: 2px;
}

button:focus,
.btn:focus,
a:focus {
  outline-color: var(--color-primary);
}

/* High contrast mode support */
@media (prefers-contrast: high) {
  :root {
    --color-text-primary: var(--color-black);
    --color-text-secondary: var(--color-gray-700);
  }
  
  .dark-mode {
    --color-text-primary: var(--color-white);
    --color-text-secondary: var(--color-gray-300);
  }
}

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

/* ==========================================================================
   CUSTOM SCROLLBAR
   ========================================================================== */

::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-track {
  background: var(--color-gray-100);
}

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

::-webkit-scrollbar-thumb:hover {
  background: var(--color-primary-dark);
}

.dark-mode ::-webkit-scrollbar-track {
  background: var(--color-gray-800);
}

/* ==========================================================================
   SELECTION STYLING
   ========================================================================== */

::selection {
  background: var(--color-primary);
  color: var(--color-white);
}

::-moz-selection {
  background: var(--color-primary);
  color: var(--color-white);
}

/* ==========================================================================
   BACK TO TOP BUTTON
   ========================================================================== */

.back-to-top {
  position: fixed;
  bottom: var(--space-6);
  right: var(--space-6);
  width: 48px;
  height: 48px;
  background: var(--color-primary);
  color: var(--color-white);
  border: none;
  border-radius: 50%;
  display: none;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  z-index: var(--z-fixed);
  transition: all var(--transition-base);
  box-shadow: var(--shadow-lg);
}

.back-to-top:hover {
  transform: translateY(-3px);
  box-shadow: var(--shadow-xl);
}

.back-to-top.show {
  display: flex;
}

/* ==========================================================================
   SERVICE FEATURES & ENHANCEMENTS
   ========================================================================== */

.service-features {
  list-style: none;
  padding: 0;
  margin-top: var(--space-4);
}

.service-features li {
  padding: var(--space-2) 0;
  border-bottom: 1px solid var(--color-gray-200);
  position: relative;
  padding-left: var(--space-6);
}

.service-features li:last-child {
  border-bottom: none;
}

.service-features li::before {
  content: '✓';
  position: absolute;
  left: 0;
  color: var(--color-primary);
  font-weight: var(--font-weight-bold);
}

.dark-mode .service-features li {
  border-bottom-color: var(--color-gray-600);
}

/* Card image container */
.card-img-container {
  position: relative;
  overflow: hidden;
}

/* Hero enhancements */
.hero-description {
  font-size: var(--font-size-lg);
  line-height: var(--line-height-relaxed);
  margin-bottom: var(--space-8);
  color: rgba(255, 255, 255, 0.9);
}

.hero-actions {
  display: flex;
  gap: var(--space-4);
  flex-wrap: wrap;
}

@media (max-width: 768px) {
  .hero-actions {
    flex-direction: column;
  }
}

/* Project enhancements */
.badge-featured {
  position: absolute;
  top: var(--space-4);
  right: var(--space-4);
  background: var(--color-accent);
  color: var(--color-white);
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-semibold);
  z-index: 2;
}

.tech-stack {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-bottom: var(--space-4);
}

.tech-tag {
  background: var(--color-primary);
  color: var(--color-white);
  padding: var(--space-1) var(--space-2);
  border-radius: var(--radius-sm);
  font-size: var(--font-size-xs);
  font-weight: var(--font-weight-medium);
}

.project-actions {
  display: flex;
  gap: var(--space-2);
  flex-wrap: wrap;
}

.project-actions .btn {
  flex: 1;
  min-width: auto;
}

@media (max-width: 576px) {
  .project-actions {
    flex-direction: column;
  }
}

/* Filter buttons */
.filter-buttons {
  display: flex;
  justify-content: center;
  flex-wrap: wrap;
  gap: var(--space-2);
}

/* Contact form enhancements */
.contact-form-container {
  background: var(--glass-background);
  backdrop-filter: var(--glass-blur);
  -webkit-backdrop-filter: var(--glass-blur);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-2xl);
  padding: var(--space-8);
  box-shadow: var(--shadow-xl);
}

.invalid-feedback {
  display: block;
  color: var(--color-error);
  font-size: var(--font-size-sm);
  margin-top: var(--space-1);
}

.form-control.is-invalid {
  border-color: var(--color-error);
}

.btn-loading {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

/* Skill enhancements */
.skill-description {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  margin-bottom: var(--space-3);
  text-align: center;
}

.skill-percentage {
  font-weight: var(--font-weight-semibold);
  color: var(--color-primary);
  font-size: var(--font-size-sm);
  text-align: center;
  display: block;
  margin-top: var(--space-2);
}

/* Testimonial enhancements */
.testimonial-rating {
  color: var(--color-warning);
  font-size: var(--font-size-lg);
  margin-bottom: var(--space-3);
}

.testimonial-position,
.testimonial-company {
  display: block;
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  font-weight: var(--font-weight-regular);
}

/* Notification system */
.notification {
  position: fixed;
  top: var(--space-6);
  right: var(--space-6);
  background: var(--color-surface);
  border-left: 4px solid var(--color-primary);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-xl);
  z-index: var(--z-tooltip);
  animation: slideInRight 0.3s ease-out;
  max-width: 400px;
}

.notification-success {
  border-left-color: var(--color-success);
}

.notification-error {
  border-left-color: var(--color-error);
}

.notification-content {
  display: flex;
  align-items: center;
  padding: var(--space-4);
  gap: var(--space-3);
}

.notification-close {
  background: none;
  border: none;
  color: var(--color-text-muted);
  cursor: pointer;
  padding: var(--space-1);
  margin-left: auto;
}

@keyframes slideInRight {
  from {
    transform: translateX(100%);
    opacity: 0;
  }
  to {
    transform: translateX(0);
    opacity: 1;
  }
}

/* Navbar scroll effect */
.navbar.scrolled {
  background: var(--color-surface);
  box-shadow: var(--shadow-md);
}

.dark-mode .navbar.scrolled {
  background: var(--color-surface);
}

/* ==========================================================================
   PRINT STYLES
   ========================================================================== */

@media print {
  *,
  *::before,
  *::after {
    background: transparent !important;
    color: black !important;
    box-shadow: none !important;
  }
  
  .navbar,
  .back-to-top,
  .dark-mode-toggle {
    display: none !important;
  }
  
  .hero {
    padding: var(--space-8) 0;
  }
}