/* Custom Fonts with Fallbacks (Part 1) */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;600;700&family=Playfair+Display:wght@700&display=swap');

/* CSS Variables with Fallbacks (Part 1) */
:root {
  /* Colors */
  --color-primary: #2563eb;
  --color-primary-dark: #1e40af;
  --color-secondary: #7c3aed;
  --color-accent: #f59e0b;
  --color-text: #1f2937;
  --color-text-light: #6b7280;
  --color-background: #ffffff;
  --color-surface: #f3f4f6;
  --color-border: #e5e7eb;
  --color-success: #10b981;
  
  /* Spacing - Relative Units (Part 1) */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 1.5rem;
  --spacing-lg: 2rem;
  --spacing-xl: 3rem;
  --spacing-2xl: 4rem;
  
  /* Typography */
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-display: 'Playfair Display', Georgia, serif;
  --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: 2rem;
  
  /* Layout */
  --max-width: 1200px;
  --border-radius: 0.5rem;
  --transition-speed: 0.3s;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

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

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

body {
  font-family: var(--font-sans, sans-serif);
  color: var(--color-text, #1f2937);
  background-color: var(--color-background, #ffffff);
  line-height: 1.6;
  font-size: var(--font-size-base, 1rem);
}

/* Typography with Custom Fonts (Part 1) */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display, serif);
  line-height: 1.2;
  margin-bottom: 1rem;
  font-weight: 700;
}

h1 {
  font-size: clamp(2rem, 5vw, var(--font-size-3xl, 2rem));
  margin-bottom: 1.5rem;
}

h2 {
  font-size: clamp(1.5rem, 4vw, var(--font-size-2xl, 1.5rem));
  color: var(--color-primary, #2563eb);
  margin-top: 2rem;
}

h3 {
  font-size: var(--font-size-xl, 1.25rem);
}

p {
  margin-bottom: 1rem;
}

/* Links with Transitions (Part 1) */
a {
  color: var(--color-primary, #2563eb);
  text-decoration: none;
  transition: color var(--transition-speed, 0.3s) ease;
}

a:hover {
  color: var(--color-primary-dark, #1e40af);
  text-decoration: underline;
}

a:focus {
  outline: 2px solid var(--color-accent, #f59e0b);
  outline-offset: 2px;
}

/* Header with Flexbox (Part 1) */
header {
  background: linear-gradient(135deg, 
    var(--color-primary, #2563eb) 0%, 
    var(--color-secondary, #7c3aed) 100%);
  color: white;
  padding: var(--spacing-lg, 2rem) var(--spacing-md, 1.5rem);
  box-shadow: var(--shadow-md, 0 4px 6px -1px rgba(0, 0, 0, 0.1));
  position: sticky;
  top: 0;
  z-index: 1000;
}

header h1 {
  color: white;
  margin: 0 0 var(--spacing-sm, 1rem) 0;
  font-size: clamp(1.5rem, 4vw, 2.5rem);
}

header > p {
  margin: 0 0 var(--spacing-md, 1.5rem) 0;
  opacity: 0.9;
}


/* Navigation with nested selectors */
nav[aria-label="Main navigation"] {
  & ul {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm, 1rem);
    list-style: none;
    padding: 0;
    
    & li {
      & a {
        color: white;
        padding: var(--spacing-xs, 0.5rem) var(--spacing-sm, 1rem);
        border-radius: var(--border-radius, 0.5rem);
        display: block;
        font-weight: 600;
        transition: all var(--transition-speed, 0.3s) ease;
        background-color: rgba(255, 255, 255, 0.1);
        
        &:hover {
          background-color: rgba(255, 255, 255, 0.2);
          transform: translateY(-2px);
          text-decoration: none;
        }
        
        &:active {
          transform: translateY(0);
        }
      }
    }
  }
}

/* Sidebar with nested structure */
.sidebar {
  background-color: var(--color-background, #ffffff);
  padding: var(--spacing-lg, 2rem);
  border-radius: var(--border-radius, 0.5rem);
  border-left: 4px solid var(--color-accent, #f59e0b);
  
  & h3 {
    color: var(--color-accent, #f59e0b);
  }
  
  & ul,
  & ol {
    margin-left: var(--spacing-md, 1.5rem);
    
    & li {
      margin-bottom: var(--spacing-xs, 0.5rem);
    }
  }
}

/*Filter buttons with nested states */
.filter-btn {
  background-color: var(--color-surface, #f3f4f6);
  color: var(--color-text, #1f2937);
  border: 2px solid var(--color-border, #e5e7eb);
  padding: var(--spacing-xs, 0.5rem) var(--spacing-md, 1.5rem);
  border-radius: var(--border-radius, 0.5rem);
  font-size: var(--font-size-base, 1rem);
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-speed, 0.3s) ease;
  font-family: var(--font-sans, sans-serif);
  
  &:hover {
    background-color: var(--color-primary, #2563eb);
    color: white;
    border-color: var(--color-primary, #2563eb);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md, 0 4px 6px -1px rgba(0, 0, 0, 0.1));
  }
  
  &:active {
    transform: translateY(0);
  }
  
  &.active {
    background-color: var(--color-primary, #2563eb);
    color: white;
    border-color: var(--color-primary, #2563eb);
    box-shadow: var(--shadow-md, 0 4px 6px -1px rgba(0, 0, 0, 0.1));
  }
}

/*Form with deeply nested structure */
form {
  background-color: var(--color-background, #ffffff);
  padding: var(--spacing-xl, 3rem);
  border-radius: var(--border-radius, 0.5rem);
  
  & fieldset {
    border: 1px solid var(--color-border, #e5e7eb);
    border-radius: var(--border-radius, 0.5rem);
    padding: var(--spacing-lg, 2rem);
    margin-bottom: var(--spacing-lg, 2rem);
    
    & legend {
      font-weight: 600;
      color: var(--color-primary, #2563eb);
      padding: 0 var(--spacing-sm, 1rem);
    }
  }
  
  & button {
    background-color: var(--color-primary, #2563eb);
    color: white;
    padding: var(--spacing-sm, 1rem) var(--spacing-lg, 2rem);
    border: none;
    border-radius: var(--border-radius, 0.5rem);
    font-size: var(--font-size-base, 1rem);
    font-weight: 600;
    cursor: pointer;
    transition: all var(--transition-speed, 0.3s) ease;
    margin-right: var(--spacing-sm, 1rem);
    
    &:hover {
      background-color: var(--color-primary-dark, #1e40af);
      transform: translateY(-2px);
      box-shadow: var(--shadow-md, 0 4px 6px -1px rgba(0, 0, 0, 0.1));
    }
    
    &[type="reset"] {
      background-color: var(--color-text-light, #6b7280);
      
      &:hover {
        background-color: var(--color-text, #1f2937);
      }
    }
  }
}

/*Project grid with nested article styling */
.project-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--spacing-lg, 2rem);
  padding: var(--spacing-lg, 2rem);
  border: 2px solid var(--color-border, #e5e7eb);
  
  & > h2 {
    grid-column: 1 / -1;
    margin-bottom: var(--spacing-md, 1.5rem);
  }
  
  & article {
    display: flex;
    flex-direction: column;
    transition: transform var(--transition-speed, 0.3s) ease;
    
    &:hover {
      transform: translateY(-8px);
      box-shadow: var(--shadow-lg, 0 10px 15px -3px rgba(0, 0, 0, 0.1));
    }
  }
}

/* Responsive Navigation with Flexbox (Part 1 & 3) */
nav[aria-label="Main navigation"] ul {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-sm, 1rem);
  list-style: none;
  padding: 0;
}

nav[aria-label="Main navigation"] ul li a {
  color: white;
  padding: var(--spacing-xs, 0.5rem) var(--spacing-sm, 1rem);
  border-radius: var(--border-radius, 0.5rem);
  display: block;
  font-weight: 600;
  transition: all var(--transition-speed, 0.3s) ease;
  background-color: rgba(255, 255, 255, 0.1);
}

nav[aria-label="Main navigation"] ul li a:hover {
  background-color: rgba(255, 255, 255, 0.2);
  transform: translateY(-2px);
  text-decoration: none;
}

nav[aria-label="Main navigation"] ul li a:active {
  transform: translateY(0);
}


header:has(nav a:hover) {
  box-shadow: var(--shadow-lg, 0 10px 15px -3px rgba(0, 0, 0, 0.1));
}

/* Main Layout with Dynamic Viewport Units (Part 1) */
main {
  max-width: var(--max-width, 1200px);
  margin: 0 auto;
  padding: var(--spacing-xl, 3rem) var(--spacing-md, 1.5rem);
  min-height: 70dvh;
}

/* Section Styling (Part 1) */
section {
  margin-bottom: var(--spacing-2xl, 4rem);
  padding: var(--spacing-lg, 2rem);
  background-color: var(--color-surface, #f3f4f6);
  border-radius: var(--border-radius, 0.5rem);
  box-shadow: var(--shadow-sm, 0 1px 2px 0 rgba(0, 0, 0, 0.05));
}

section h2 {
  margin-top: 0;
  padding-bottom: var(--spacing-sm, 1rem);
  border-bottom: 2px solid var(--color-primary, #2563eb);
}

section article {
  background-color: var(--color-background, #ffffff);
  padding: var(--spacing-md, 1.5rem);
  border-radius: var(--border-radius, 0.5rem);
  margin-bottom: var(--spacing-md, 1.5rem);
}

section article h3,
section article h4 {
  color: var(--color-secondary, #7c3aed);
}

/* Flexbox layout for article content */
section article > div {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-md, 1.5rem);
}

section article > div picture {
  flex-shrink: 0;
}

section article > div > div {
  display: flex;
  flex-direction: column;
  gap: var(--spacing-sm, 1rem);
}

/* Project Grid with CSS Grid (Part 1) */
.project-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: var(--spacing-lg, 2rem);
  padding: var(--spacing-lg, 2rem);
  border: 2px solid var(--color-border, #e5e7eb);
}

.project-grid > h2 {
  grid-column: 1 / -1;
  margin-bottom: var(--spacing-md, 1.5rem);
}

.project-grid article {
  display: flex;
  flex-direction: column;
  transition: transform var(--transition-speed, 0.3s) ease;
}

.project-grid article:hover {
  transform: translateY(-8px);
  box-shadow: var(--shadow-lg, 0 10px 15px -3px rgba(0, 0, 0, 0.1));
}

/* Responsive Images (Part 2) */
img {
  max-width: 100%;
  height: auto;
  display: block;
  border-radius: var(--border-radius, 0.5rem);
}

picture {
  display: block;
  margin: var(--spacing-md, 1.5rem) 0;
}

picture img {
  width: 100%;
  object-fit: cover;
  object-position: center;
}

/* Sidebar */
.sidebar {
  background-color: var(--color-background, #ffffff);
  padding: var(--spacing-lg, 2rem);
  border-radius: var(--border-radius, 0.5rem);
  border-left: 4px solid var(--color-accent, #f59e0b);
}

.sidebar h3 {
  color: var(--color-accent, #f59e0b);
}

.sidebar ul,
.sidebar ol {
  margin-left: var(--spacing-md, 1.5rem);
}

.sidebar ul li,
.sidebar ol li {
  margin-bottom: var(--spacing-xs, 0.5rem);
}

/* Form Styling (Part 1) */
form {
  background-color: var(--color-background, #ffffff);
  padding: var(--spacing-xl, 3rem);
  border-radius: var(--border-radius, 0.5rem);
}

form fieldset {
  border: 1px solid var(--color-border, #e5e7eb);
  border-radius: var(--border-radius, 0.5rem);
  padding: var(--spacing-lg, 2rem);
  margin-bottom: var(--spacing-lg, 2rem);
}

form fieldset legend {
  font-weight: 600;
  color: var(--color-primary, #2563eb);
  padding: 0 var(--spacing-sm, 1rem);
}

form label {
  display: block;
  margin-bottom: var(--spacing-xs, 0.5rem);
  font-weight: 600;
  color: var(--color-text, #1f2937);
}

form input[type="text"],
form input[type="email"],
form input[type="tel"],
form textarea,
form select {
  width: 100%;
  padding: var(--spacing-sm, 1rem);
  border: 2px solid var(--color-border, #e5e7eb);
  border-radius: var(--border-radius, 0.5rem);
  font-size: var(--font-size-base, 1rem);
  font-family: var(--font-sans, sans-serif);
  transition: border-color var(--transition-speed, 0.3s) ease;
}

form input[type="text"]:focus,
form input[type="email"]:focus,
form input[type="tel"]:focus,
form textarea:focus,
form select:focus {
  outline: none;
  border-color: var(--color-primary, #2563eb);
  box-shadow: 0 0 0 3px rgba(37, 99, 235, 0.1);
}

form textarea {
  resize: vertical;
  min-height: 120px;
}

form button {
  background-color: var(--color-primary, #2563eb);
  color: white;
  padding: var(--spacing-sm, 1rem) var(--spacing-lg, 2rem);
  border: none;
  border-radius: var(--border-radius, 0.5rem);
  font-size: var(--font-size-base, 1rem);
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-speed, 0.3s) ease;
  margin-right: var(--spacing-sm, 1rem);
}

form button:hover {
  background-color: var(--color-primary-dark, #1e40af);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md, 0 4px 6px -1px rgba(0, 0, 0, 0.1));
}

form button:active {
  transform: translateY(0);
}

form button[type="reset"] {
  background-color: var(--color-text-light, #6b7280);
}

form button[type="reset"]:hover {
  background-color: var(--color-text, #1f2937);
}

form div {
  margin-bottom: var(--spacing-md, 1.5rem);
}

/* Progress Bar Styling */
progress {
  width: 100%;
  height: 1.5rem;
  border-radius: var(--border-radius, 0.5rem);
  overflow: hidden;
  appearance: none;
}

progress::-webkit-progress-bar {
  background-color: var(--color-surface, #f3f4f6);
  border-radius: var(--border-radius, 0.5rem);
}

progress::-webkit-progress-value {
  background: linear-gradient(90deg, 
    var(--color-primary, #2563eb), 
    var(--color-success, #10b981));
  border-radius: var(--border-radius, 0.5rem);
  transition: width 0.5s ease;
}

progress::-moz-progress-bar {
  background: linear-gradient(90deg, 
    var(--color-primary, #2563eb), 
    var(--color-success, #10b981));
  border-radius: var(--border-radius, 0.5rem);
}

/* CSS Animations, Transitions, and Transforms (Part 1) */
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes slideInFromLeft {
  from {
    opacity: 0;
    transform: translateX(-50px);
  }
  to {
    opacity: 1;
    transform: translateX(0);
  }
}

@keyframes pulse {
  0%, 100% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.05);
  }
}

section {
  animation: fadeIn 0.6s ease-out;
}

/* Button hover animation */
button,
input[type="submit"],
input[type="button"] {
  position: relative;
  overflow: hidden;
}

button::after,
input[type="submit"]::after,
input[type="button"]::after {
  content: '';
  position: absolute;
  top: 50%;
  left: 50%;
  width: 0;
  height: 0;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.3);
  transform: translate(-50%, -50%);
  transition: width 0.6s, height 0.6s;
}

button:hover::after,
input[type="submit"]:hover::after,
input[type="button"]:hover::after {
  width: 300px;
  height: 300px;
}

/* Navigation link animation */
nav a {
  position: relative;
}

nav a::before {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--color-accent, #f59e0b);
  transition: width var(--transition-speed, 0.3s) ease;
}

nav a:hover::before {
  width: 100%;
}

/* Dialog Styling */
dialog {
  border: none;
  border-radius: var(--border-radius, 0.5rem);
  padding: var(--spacing-lg, 2rem);
  box-shadow: var(--shadow-lg, 0 10px 15px -3px rgba(0, 0, 0, 0.1));
  background-color: var(--color-background, #ffffff);
  max-width: 90vw;
}

dialog[open] {
  animation: slideInFromLeft 0.4s ease-out;
}

/* Custom Elements Styling */
project-card,
demo-card {
  display: block;
  padding: var(--spacing-lg, 2rem);
  margin: var(--spacing-md, 1.5rem) 0;
  background-color: var(--color-surface, #f3f4f6);
  border-radius: var(--border-radius, 0.5rem);
  border-left: 4px solid var(--color-secondary, #7c3aed);
}

project-card h3,
project-card h4,
demo-card h3,
demo-card h4 {
  margin-top: 0;
  color: var(--color-secondary, #7c3aed);
}

/* Filter Buttons Styling */
.filter-buttons {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-sm, 1rem);
  align-items: center;
  margin-top: var(--spacing-md, 1.5rem);
}

.filter-buttons p {
  margin: 0;
  font-weight: 600;
  color: var(--color-text, #1f2937);
}

/* Filter button styling */
.filter-btn {
  background-color: var(--color-surface, #f3f4f6);
  color: var(--color-text, #1f2937);
  border: 2px solid var(--color-border, #e5e7eb);
  padding: var(--spacing-xs, 0.5rem) var(--spacing-md, 1.5rem);
  border-radius: var(--border-radius, 0.5rem);
  font-size: var(--font-size-base, 1rem);
  font-weight: 600;
  cursor: pointer;
  transition: all var(--transition-speed, 0.3s) ease;
  font-family: var(--font-sans, sans-serif);
}

.filter-btn:hover {
  background-color: var(--color-primary, #2563eb);
  color: white;
  border-color: var(--color-primary, #2563eb);
  transform: translateY(-2px);
  box-shadow: var(--shadow-md, 0 4px 6px -1px rgba(0, 0, 0, 0.1));
}

.filter-btn:active {
  transform: translateY(0);
}

.filter-btn.active {
  background-color: var(--color-primary, #2563eb);
  color: white;
  border-color: var(--color-primary, #2563eb);
  box-shadow: var(--shadow-md, 0 4px 6px -1px rgba(0, 0, 0, 0.1));
}

/* Hidden projects for filtering */
.project-grid article.hidden {
  display: none;
}

/* Breadcrumb Navigation */
nav[aria-label="Breadcrumb"] {
  margin-bottom: var(--spacing-lg, 2rem);
}

nav[aria-label="Breadcrumb"] ol {
  display: flex;
  gap: var(--spacing-xs, 0.5rem);
  list-style: none;
  flex-wrap: wrap;
}

nav[aria-label="Breadcrumb"] ol li {
  display: flex;
  align-items: center;
}

nav[aria-label="Breadcrumb"] ol li::after {
  content: '›';
  margin-left: var(--spacing-xs, 0.5rem);
  color: var(--color-text-light, #6b7280);
}

nav[aria-label="Breadcrumb"] ol li:last-child::after {
  content: '';
}

nav[aria-label="Breadcrumb"] ol li:last-child {
  font-weight: 600;
  color: var(--color-text, #1f2937);
}

/* Footer */
footer {
  background-color: var(--color-text, #1f2937);
  color: white;
  padding: var(--spacing-xl, 3rem) var(--spacing-md, 1.5rem);
  text-align: center;
  margin-top: var(--spacing-2xl, 4rem);
}

footer a {
  color: var(--color-accent, #f59e0b);
}

footer a:hover {
  color: white;
}

footer p {
  margin-bottom: var(--spacing-sm, 1rem);
}

footer p:last-child {
  margin-bottom: 0;
}

/* SVG Styling */
svg {
  max-width: 100%;
  height: auto;
  display: block;
  margin: var(--spacing-md, 1.5rem) auto;
}

/* Responsive Iframe */
iframe {
  max-width: 100%;
  border-radius: var(--border-radius, 0.5rem);
  display: block;
  margin: var(--spacing-md, 1.5rem) 0;
}

/* RESPONSIVE DESIGN - MOBILE FIRST (Part 3) */

/* Pure CSS Hamburger Menu (no JavaScript required) */
.menu-toggle-checkbox {
  display: none;
}

.menu-toggle-label {
  display: none;
  background: none;
  border: none;
  color: white;
  font-size: 1.5rem;
  cursor: pointer;
  padding: var(--spacing-xs, 0.5rem);
  position: relative;
  z-index: 1001;
}

.hamburger-icon {
  display: flex;
  flex-direction: column;
  gap: 4px;
  width: 24px;
}

.hamburger-icon span {
  display: block;
  width: 100%;
  height: 3px;
  background: white;
  border-radius: 2px;
  transition: all 0.3s ease;
}

/* Mobile Styles (< 768px) - Part 3 */
@media (max-width: 767px) {
  .menu-toggle-label {
    display: block;
    margin-bottom: var(--spacing-sm, 1rem);
  }
  
  header nav[aria-label="Main navigation"] ul {
    flex-direction: column;
    max-height: 0;
    overflow: hidden;
    transition: max-height 0.3s ease;
  }
  
  /* When checkbox is checked, show menu */
  .menu-toggle-checkbox:checked ~ nav[aria-label="Main navigation"] ul {
    max-height: 500px;
  }
  
  /* Animate hamburger to X when open */
  .menu-toggle-checkbox:checked ~ .menu-toggle-label .hamburger-icon span:nth-child(1) {
    transform: rotate(45deg) translateY(7px);
  }
  
  .menu-toggle-checkbox:checked ~ .menu-toggle-label .hamburger-icon span:nth-child(2) {
    opacity: 0;
  }
  
  .menu-toggle-checkbox:checked ~ .menu-toggle-label .hamburger-icon span:nth-child(3) {
    transform: rotate(-45deg) translateY(-7px);
  }
  
  header nav[aria-label="Main navigation"] ul li {
    width: 100%;
  }
  
  header nav[aria-label="Main navigation"] ul li a {
    width: 100%;
    text-align: center;
  }
  
  main {
    padding: var(--spacing-lg, 2rem) var(--spacing-sm, 1rem);
  }
  
  section {
    padding: var(--spacing-md, 1.5rem);
    margin-bottom: var(--spacing-lg, 2rem);
  }
  
  .project-grid {
    grid-template-columns: 1fr;
    gap: var(--spacing-md, 1.5rem);
  }
  
  form {
    padding: var(--spacing-lg, 2rem) var(--spacing-md, 1.5rem);
  }
  
  form button {
    width: 100%;
    margin-bottom: var(--spacing-sm, 1rem);
    margin-right: 0;
  }
  
  h1 {
    font-size: 1.75rem;
  }
  
  h2 {
    font-size: 1.5rem;
  }
  
  dialog {
    max-width: 95vw;
    padding: var(--spacing-md, 1.5rem);
  }
  
  iframe {
    width: 100%;
    height: auto;
    aspect-ratio: 16 / 9;
  }
  
  /* Touch-friendly sizing */
  button,
  a {
    min-height: 44px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
  }
  
  nav[aria-label="Main navigation"] ul li a {
    padding: var(--spacing-md, 1.5rem) var(--spacing-sm, 1rem);
  }
  
  /* Filter buttons stack on mobile */
  .filter-buttons {
    flex-direction: column;
    align-items: stretch;
  }
  
  .filter-btn {
    width: 100%;
    text-align: center;
  }
}

/* Tablet Styles (768px - 1023px) - Part 3 */
@media (min-width: 768px) and (max-width: 1023px) {
  header nav[aria-label="Main navigation"] ul {
    justify-content: center;
    gap: var(--spacing-xs, 0.5rem);
  }
  
  header nav[aria-label="Main navigation"] ul li a {
    padding: var(--spacing-xs, 0.5rem) var(--spacing-sm, 1rem);
    font-size: var(--font-size-sm, 0.875rem);
  }
  
  .project-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-md, 1.5rem);
  }
  
  main {
    padding: var(--spacing-xl, 3rem) var(--spacing-lg, 2rem);
  }
  
  section {
    padding: var(--spacing-lg, 2rem) var(--spacing-md, 1.5rem);
  }
  
  form fieldset > div {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-md, 1.5rem);
  }
  
  section:has(.sidebar) {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: var(--spacing-lg, 2rem);
    align-items: start;
  }
  
  section:has(.sidebar) > h2 {
    grid-column: 1 / -1;
    margin-bottom: var(--spacing-md, 1.5rem);
  }
  
  section:has(.sidebar) > article {
    margin-bottom: 0;
  }
  
  /* Article content side-by-side */
  article > div {
    flex-direction: row;
    align-items: flex-start;
  }
  
  article > div picture {
    flex: 0 0 45%;
    max-width: 45%;
  }
  
  article > div > div {
    flex: 1;
  }
}

/* Desktop Styles (1024px+) - Part 3 */
@media (min-width: 1024px) {
  header nav[aria-label="Main navigation"] ul {
    justify-content: flex-start;
    gap: var(--spacing-md, 1.5rem);
  }
  
  .project-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-lg, 2rem);
  }
  
  main {
    padding: var(--spacing-2xl, 4rem) var(--spacing-xl, 3rem);
  }
  
  section:has(article):has(.sidebar) {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: var(--spacing-xl, 3rem);
    align-items: start;
  }
  
  section:has(article):has(.sidebar) > h2 {
    grid-column: 1 / -1;
    margin-bottom: var(--spacing-lg, 2rem);
  }
  
  section:has(article):has(.sidebar) > article {
    margin-bottom: 0;
  }
  
  /* Article content optimized for desktop */
  article > div {
    gap: var(--spacing-lg, 2rem);
  }
  
  article > div picture {
    flex: 0 0 50%;
    max-width: 50%;
  }
  
  picture img {
    max-height: 600px;
    object-fit: cover;
  }
  
  .project-grid article:hover {
    transform: translateY(-12px);
  }
  
  form fieldset > div {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-lg, 2rem);
  }
  
  form fieldset > div:has(textarea),
  form fieldset > div:has(input[type="range"]) {
    grid-column: 1 / -1;
  }
}

/* Print Styles */
@media print {
  header,
  nav,
  footer,
  button,
  dialog {
    display: none;
  }
  
  main {
    max-width: 100%;
    padding: 0;
  }
  
  section {
    page-break-inside: avoid;
    box-shadow: none;
  }
  
  a {
    color: black;
    text-decoration: underline;
  }
  
  a[href]::after {
    content: " (" attr(href) ")";
    font-size: 0.8em;
  }
}

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

/* Dark Mode Support */
@media (prefers-color-scheme: dark) {
  :root {
    --color-text: #f3f4f6;
    --color-text-light: #d1d5db;
    --color-background: #1f2937;
    --color-surface: #374151;
    --color-border: #4b5563;
  }
  
  header {
    background: linear-gradient(135deg, #1e40af 0%, #6b21a8 100%);
  }
  
  img {
    opacity: 0.9;
  }
}

/* Landscape Orientation */
@media (orientation: landscape) and (max-height: 500px) {
  header {
    padding: var(--spacing-sm, 1rem);
  }
  
  header h1 {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-xs, 0.5rem);
  }
  
  header > p {
    display: none;
  }
  
  section {
    padding: var(--spacing-md, 1.5rem);
    margin-bottom: var(--spacing-md, 1.5rem);
  }
}

/* Accessibility */
*:focus-visible {
  outline: 3px solid var(--color-accent, #f59e0b);
  outline-offset: 2px;
}

.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  background: var(--color-primary, #2563eb);
  color: white;
  padding: var(--spacing-sm, 1rem);
  text-decoration: none;
  z-index: 100;
}

.skip-link:focus {
  top: 0;
}

/* High Contrast Mode Support */
@media (prefers-contrast: more) {
  * {
    border-width: 2px;
  }
  
  button,
  input,
  select,
  textarea {
    border: 2px solid currentColor;
  }
}

/* Noscript Styling */
noscript {
  display: block;
  padding: var(--spacing-md, 1.5rem);
  background-color: var(--color-accent, #f59e0b);
  color: var(--color-text, #1f2937);
  text-align: center;
  font-weight: 600;
}

@import url('project-cards-styles.css');