/* Modern CSS Reset and Base Styles (2025) */

/* CSS Custom Properties for consistent theming */
:root {
  /* Colors */
  --color-primary: #2c3e50;
  --color-secondary: #3498db;
  --color-accent: #e74c3c;
  --color-text: #333333;
  --color-text-light: #666666;
  --color-text-inverse: #ffffff;
  --color-background: #ffffff;
  --color-background-alt: #f8f9fa;
  --color-border: #e9ecef;
  
  /* Typography */
  --font-family-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-family-mono: 'SF Mono', Consolas, 'Liberation Mono', Menlo, monospace;
  
  /* Spacing */
  --spacing-xs: 0.25rem;
  --spacing-sm: 0.5rem;
  --spacing-md: 1rem;
  --spacing-lg: 1.5rem;
  --spacing-xl: 2rem;
  --spacing-xxl: 3rem;
  
  /* Border radius */
  --border-radius-sm: 4px;
  --border-radius-md: 8px;
  --border-radius-lg: 12px;
  
  /* Shadows */
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1), 0 2px 4px -2px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  
  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-normal: 250ms ease;
  --transition-slow: 500ms ease;
  
  /* Z-index scale */
  --z-dropdown: 1000;
  --z-sticky: 1020;
  --z-fixed: 1030;
  --z-modal: 1040;
  --z-popover: 1050;
  --z-tooltip: 1060;
}

/* Dark mode support */
@media (prefers-color-scheme: dark) {
  :root {
    --color-primary: #34495e;
    --color-text: #e9ecef;
    --color-text-light: #adb5bd;
    --color-background: #1a1a1a;
    --color-background-alt: #2d2d2d;
    --color-border: #444444;
  }
}

/* Modern CSS Reset */
*,
*::before,
*::after {
  box-sizing: border-box;
}

* {
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
  scroll-padding-top: 2rem;
}

body {
  font-family: var(--font-family-primary);
  font-size: 1rem;
  line-height: 1.6;
  color: var(--color-text);
  background-color: var(--color-background);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  text-rendering: optimizeLegibility;
}

/* Accessibility improvements */
.visually-hidden {
  position: absolute !important;
  width: 1px !important;
  height: 1px !important;
  padding: 0 !important;
  margin: -1px !important;
  overflow: hidden !important;
  clip: rect(0, 0, 0, 0) !important;
  white-space: nowrap !important;
  border: 0 !important;
}

.skip-link {
  position: absolute;
  top: -40px;
  left: 6px;
  background: var(--color-primary);
  color: var(--color-text-inverse);
  padding: 8px;
  text-decoration: none;
  border-radius: var(--border-radius-sm);
  z-index: var(--z-tooltip);
  transition: top var(--transition-fast);
}

.skip-link:focus {
  top: 6px;
}

/* Focus management */
:focus-visible {
  outline: 2px solid var(--color-secondary);
  outline-offset: 2px;
}

/* 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;
    scroll-behavior: auto !important;
  }
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-weight: 600;
  line-height: 1.2;
  margin-bottom: var(--spacing-md);
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }
h5 { font-size: 1.125rem; }
h6 { font-size: 1rem; }

p {
  margin-bottom: var(--spacing-md);
}

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

a:hover,
a:focus {
  color: var(--color-accent);
  text-decoration: underline;
}

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

/* Layout */
.container {
  max-width: 1200px;
  margin: 0 auto;
  padding: 0 var(--spacing-md);
}

/* Header */
#header {
  position: fixed;
  top: 0;
  left: 0;
  width: 280px;
  height: 100vh;
  background: var(--color-primary);
  color: var(--color-text-inverse);
  z-index: var(--z-fixed);
  display: flex;
  flex-direction: column;
  transform: translateX(-100%);
  transition: transform var(--transition-normal);
}

.header-visible #header {
  transform: translateX(0);
}

#header .top {
  flex: 1;
  padding: var(--spacing-xl);
}

#header .bottom {
  padding: var(--spacing-xl);
}

#logo h1 {
  font-size: 1.5rem;
  margin-bottom: var(--spacing-sm);
  color: var(--color-text-inverse);
}

#logo p {
  font-size: 0.9rem;
  opacity: 0.8;
  margin-bottom: 0;
}

/* Navigation */
#nav ul {
  list-style: none;
  margin-top: var(--spacing-xl);
}

#nav li {
  margin-bottom: var(--spacing-sm);
}

#nav a {
  display: flex;
  align-items: center;
  padding: var(--spacing-sm) var(--spacing-md);
  color: var(--color-text-inverse);
  border-radius: var(--border-radius-sm);
  transition: background-color var(--transition-fast);
}

#nav a:hover,
#nav a:focus,
#nav a.active {
  background-color: rgba(255, 255, 255, 0.1);
  text-decoration: none;
}

#nav .icon {
  margin-right: var(--spacing-sm);
  width: 1.2em;
}

/* Social icons */
.icons {
  list-style: none;
  display: flex;
  gap: var(--spacing-sm);
  flex-wrap: wrap;
}

.icons a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.5em;
  height: 2.5em;
  border-radius: 50%;
  background: rgba(255, 255, 255, 0.1);
  color: var(--color-text-inverse);
  transition: all var(--transition-fast);
}

.icons a:hover,
.icons a:focus {
  background: var(--color-secondary);
  transform: translateY(-2px);
  text-decoration: none;
}

/* Main content */
#main {
  margin-left: 0;
  min-height: 100vh;
  padding-top: var(--spacing-xxl);
}

/* Sections */
section {
  padding: var(--spacing-xxl) 0;
  min-height: 100vh;
  display: flex;
  align-items: center;
}

section:first-child {
  background: linear-gradient(135deg, var(--color-primary) 0%, #34495e 100%);
  color: var(--color-text-inverse);
}

section:nth-child(even) {
  background: var(--color-background-alt);
}

/* About section */
.about-content p {
  text-align: justify;
  margin-bottom: var(--spacing-lg);
}

/* Tools section */
.tools-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: var(--spacing-xl);
  margin-top: var(--spacing-xl);
}

.tool-item {
  background: var(--color-background);
  border-radius: var(--border-radius-lg);
  overflow: hidden;
  box-shadow: var(--shadow-md);
  transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}

.tool-item:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.tool-item img {
  width: 100%;
  height: 200px;
  object-fit: cover;
}

.tool-item header {
  padding: var(--spacing-lg);
}

.tool-item h3 {
  margin-bottom: var(--spacing-sm);
  color: var(--color-primary);
}

/* Contact section */
.contact-icons {
  justify-content: center;
  margin-top: var(--spacing-xl);
}

.contact-icons a {
  width: 4em;
  height: 4em;
  background: var(--color-secondary);
  color: var(--color-text-inverse);
  margin: var(--spacing-sm);
}

.contact-icons a:hover {
  background: var(--color-accent);
}

/* Footer */
#footer {
  background: var(--color-primary);
  color: var(--color-text-inverse);
  text-align: center;
  padding: var(--spacing-xl);
}

.copyright {
  list-style: none;
  display: flex;
  justify-content: center;
  gap: var(--spacing-lg);
  flex-wrap: wrap;
}

.copyright li {
  font-size: 0.9rem;
  opacity: 0.8;
}

/* Mobile menu toggle */
#headerToggle {
  position: fixed;
  top: var(--spacing-md);
  left: var(--spacing-md);
  z-index: var(--z-modal);
  display: none;
}

#headerToggle button {
  background: var(--color-primary);
  color: var(--color-text-inverse);
  border: none;
  padding: var(--spacing-sm);
  border-radius: var(--border-radius-sm);
  font-size: 1.2rem;
  cursor: pointer;
  transition: background-color var(--transition-fast);
}

#headerToggle button:hover,
#headerToggle button:focus {
  background: var(--color-secondary);
}

/* Responsive design */
@media (max-width: 1200px) {
  #main {
    margin-left: 0;
  }
  
  #header {
    transform: translateX(-100%);
  }
  
  #headerToggle {
    display: block;
  }
}

@media (max-width: 768px) {
  :root {
    --spacing-xxl: 2rem;
  }
  
  #header {
    width: 100%;
  }
  
  .container {
    padding: 0 var(--spacing-sm);
  }
  
  section {
    min-height: auto;
    padding: var(--spacing-xl) 0;
  }
  
  h1 { font-size: 2rem; }
  h2 { font-size: 1.75rem; }
  
  .tools-grid {
    grid-template-columns: 1fr;
    gap: var(--spacing-lg);
  }
  
  .copyright {
    flex-direction: column;
    gap: var(--spacing-sm);
  }
}

@media (max-width: 480px) {
  .contact-icons a {
    width: 3em;
    height: 3em;
    margin: var(--spacing-xs);
  }
}

/* Print styles */
@media print {
  #header,
  #headerToggle,
  .icons {
    display: none;
  }
  
  #main {
    margin-left: 0;
  }
  
  section {
    page-break-inside: avoid;
    min-height: auto;
  }
  
  a {
    color: var(--color-text);
    text-decoration: underline;
  }
}

/* High contrast mode support */
@media (prefers-contrast: high) {
  :root {
    --color-text: #000000;
    --color-background: #ffffff;
    --color-border: #000000;
  }
}

/* Animation for loading state */
@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.fade-in {
  animation: fadeIn 0.6s ease-out;
}

/* Loading state */
body.is-loading * {
  animation-play-state: paused !important;
}

/* Custom scrollbar */
::-webkit-scrollbar {
  width: 8px;
}

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

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

::-webkit-scrollbar-thumb:hover {
  background: var(--color-text-light);
}