/* ========================================
   PERSONAL WEBSITE - MAIN STYLESHEET
   Modern, minimal, developer-focused design
   ======================================== */

/* ========================================
   CSS VARIABLES - DESIGN TOKENS
   ======================================== */
:root {
  /* COLORS - Light Mode */
  --color-bg: #fafaf9;
  --color-surface: #ffffff;
  --color-text-primary: #1c1917;
  --color-text-secondary: #57534e;
  --color-text-muted: #78716c;
  --color-border: #e7e5e4;
  --color-accent: #ea580c;
  --color-accent-hover: #c2410c;
  --color-code-bg: #f5f5f4;
  --color-shadow: rgba(0, 0, 0, 0.05);
  
  /* TYPOGRAPHY */
  --font-display: 'Spectral', 'Georgia', serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  --font-mono: 'JetBrains Mono', 'Fira Code', 'Courier New', monospace;
  
  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 1.875rem;
  --text-4xl: 2.25rem;
  --text-5xl: 3rem;
  --text-6xl: 3.75rem;
  
  /* SPACING */
  --space-xs: 0.5rem;
  --space-sm: 0.75rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;
  --space-4xl: 6rem;
  
  /* LAYOUT */
  --max-width-prose: 65ch;
  --max-width-wide: 1200px;
  --max-width-full: 1400px;
  
  /* EFFECTS */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
  --transition-slow: 400ms ease;
  --shadow-sm: 0 1px 2px var(--color-shadow);
  --shadow-md: 0 4px 6px var(--color-shadow);
  --shadow-lg: 0 10px 15px var(--color-shadow);
}

/* Dark Mode Variables */
[data-theme="dark"] {
  --color-bg: #0c0a09;
  --color-surface: #1c1917;
  --color-text-primary: #fafaf9;
  --color-text-secondary: #d6d3d1;
  --color-text-muted: #a8a29e;
  --color-border: #292524;
  --color-accent: #fb923c;
  --color-accent-hover: #fdba74;
  --color-code-bg: #292524;
  --color-shadow: rgba(0, 0, 0, 0.3);
}

/* ========================================
   RESET & BASE STYLES
   ======================================== */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: var(--font-body);
  font-size: var(--text-base);
  line-height: 1.7;
  color: var(--color-text-primary);
  background-color: var(--color-bg);
  transition: background-color var(--transition-base), color var(--transition-base);
}

/* ========================================
   TYPOGRAPHY
   ======================================== */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-display);
  font-weight: 600;
  line-height: 1.2;
  color: var(--color-text-primary);
  margin-bottom: var(--space-lg);
}

h1 { font-size: var(--text-5xl); }
h2 { font-size: var(--text-4xl); }
h3 { font-size: var(--text-3xl); }
h4 { font-size: var(--text-2xl); }
h5 { font-size: var(--text-xl); }
h6 { font-size: var(--text-lg); }

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

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

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

strong { font-weight: 600; }
em { font-style: italic; }

/* Code Typography */
code, pre {
  font-family: var(--font-mono);
  font-size: 0.9em;
}

code {
  background-color: var(--color-code-bg);
  padding: 0.2em 0.4em;
  border-radius: 3px;
  color: var(--color-accent);
}

pre {
  background-color: var(--color-code-bg);
  padding: var(--space-lg);
  border-radius: 8px;
  overflow-x: auto;
  margin-bottom: var(--space-lg);
  border: 1px solid var(--color-border);
}

pre code {
  background: none;
  padding: 0;
  color: var(--color-text-secondary);
}

/* ========================================
   LAYOUT COMPONENTS
   ======================================== */

/* Header Navigation */
.header {
  position: sticky;
  top: 0;
  z-index: 100;
  background-color: var(--color-bg);
  border-bottom: 1px solid var(--color-border);
  backdrop-filter: blur(10px);
  background-color: rgba(250, 250, 249, 0.8);
  transition: all var(--transition-base);
}

[data-theme="dark"] .header {
  background-color: rgba(12, 10, 9, 0.8);
}

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

.logo {
  font-family: var(--font-display);
  font-size: var(--text-xl);
  font-weight: 700;
  color: var(--color-text-primary);
  transition: color var(--transition-fast);
}

.logo:hover {
  color: var(--color-accent);
}

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

.nav-link {
  font-size: var(--text-sm);
  font-weight: 500;
  color: var(--color-text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  position: relative;
  transition: color var(--transition-fast);
}

.nav-link::after {
  content: '';
  position: absolute;
  bottom: -4px;
  left: 0;
  width: 0;
  height: 2px;
  background-color: var(--color-accent);
  transition: width var(--transition-base);
}

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

.nav-link:hover,
.nav-link.active {
  color: var(--color-accent);
}

/* Theme Toggle Button */
.theme-toggle {
  background: none;
  border: 1px solid var(--color-border);
  width: 40px;
  height: 40px;
  border-radius: 50%;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
  color: var(--color-text-primary);
}

.theme-toggle:hover {
  background-color: var(--color-surface);
  border-color: var(--color-accent);
  transform: rotate(20deg);
}

/* Container Utilities */
.container {
  max-width: var(--max-width-wide);
  margin: 0 auto;
  padding: 0 var(--space-xl);
}

.container-narrow {
  max-width: var(--max-width-prose);
  margin: 0 auto;
  padding: 0 var(--space-xl);
}

/* ========================================
   HERO SECTION
   ======================================== */
.hero {
  min-height: 85vh;
  display: flex;
  align-items: center;
  padding: var(--space-4xl) 0;
}

.hero-content {
  max-width: 800px;
}

.hero-title {
  font-size: clamp(2.5rem, 8vw, 5rem);
  margin-bottom: var(--space-xl);
  line-height: 1.1;
  animation: fadeInUp 0.8s ease;
}

.hero-subtitle {
  font-size: var(--text-2xl);
  color: var(--color-text-secondary);
  margin-bottom: var(--space-2xl);
  animation: fadeInUp 0.8s ease 0.2s backwards;
}

.hero-description {
  font-size: var(--text-lg);
  color: var(--color-text-muted);
  margin-bottom: var(--space-2xl);
  max-width: 600px;
  animation: fadeInUp 0.8s ease 0.4s backwards;
}

/* ========================================
   BUTTONS
   ======================================== */
.btn {
  display: inline-block;
  padding: var(--space-md) var(--space-xl);
  font-family: var(--font-body);
  font-size: var(--text-base);
  font-weight: 500;
  text-align: center;
  border: none;
  border-radius: 6px;
  cursor: pointer;
  transition: all var(--transition-fast);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.btn-primary {
  background-color: var(--color-accent);
  color: white;
  box-shadow: 0 2px 4px rgba(234, 88, 12, 0.2);
}

.btn-primary:hover {
  background-color: var(--color-accent-hover);
  transform: translateY(-2px);
  box-shadow: 0 4px 8px rgba(234, 88, 12, 0.3);
  color: white;
}

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

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

/* ========================================
   CARD COMPONENTS
   ======================================== */
.card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: 12px;
  padding: var(--space-2xl);
  transition: all var(--transition-base);
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
  border-color: var(--color-accent);
}

.card-title {
  font-size: var(--text-2xl);
  margin-bottom: var(--space-md);
}

.card-meta {
  font-size: var(--text-sm);
  color: var(--color-text-muted);
  margin-bottom: var(--space-lg);
  display: flex;
  gap: var(--space-md);
  align-items: center;
}

.card-excerpt {
  color: var(--color-text-secondary);
  margin-bottom: var(--space-lg);
}

.card-link {
  font-weight: 500;
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
}

.card-link::after {
  content: '→';
  transition: transform var(--transition-fast);
}

.card-link:hover::after {
  transform: translateX(4px);
}

/* ========================================
   BLOG GRID
   ======================================== */
.blog-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
  gap: var(--space-2xl);
  margin-bottom: var(--space-4xl);
}

/* ========================================
   BLOG POST (DETAIL PAGE)
   ======================================== */
.post-header {
  text-align: center;
  max-width: var(--max-width-prose);
  margin: 0 auto var(--space-4xl);
  padding-top: var(--space-4xl);
}

.post-title {
  font-size: clamp(2rem, 5vw, 3.5rem);
  margin-bottom: var(--space-lg);
}

.post-meta {
  font-size: var(--text-base);
  color: var(--color-text-muted);
  display: flex;
  justify-content: center;
  gap: var(--space-lg);
  flex-wrap: wrap;
}

.post-content {
  max-width: var(--max-width-prose);
  margin: 0 auto;
  padding-bottom: var(--space-4xl);
}

.post-content h2 {
  margin-top: var(--space-3xl);
  margin-bottom: var(--space-lg);
}

.post-content h3 {
  margin-top: var(--space-2xl);
  margin-bottom: var(--space-md);
}

.post-content img {
  max-width: 100%;
  border-radius: 8px;
  margin: var(--space-2xl) 0;
}

.post-content ul, 
.post-content ol {
  margin-bottom: var(--space-lg);
  padding-left: var(--space-xl);
  color: var(--color-text-secondary);
}

.post-content li {
  margin-bottom: var(--space-sm);
}

.post-content blockquote {
  border-left: 4px solid var(--color-accent);
  padding-left: var(--space-lg);
  margin: var(--space-2xl) 0;
  font-style: italic;
  color: var(--color-text-secondary);
}

/* ========================================
   CONTACT FORM
   ======================================== */
.contact-section {
  max-width: 600px;
  margin: 0 auto;
  padding: var(--space-4xl) var(--space-xl);
}

.form-group {
  margin-bottom: var(--space-xl);
}

.form-label {
  display: block;
  font-size: var(--text-sm);
  font-weight: 500;
  margin-bottom: var(--space-sm);
  color: var(--color-text-primary);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.form-input,
.form-textarea {
  width: 100%;
  padding: var(--space-md);
  font-family: var(--font-body);
  font-size: var(--text-base);
  color: var(--color-text-primary);
  background-color: var(--color-surface);
  border: 2px solid var(--color-border);
  border-radius: 6px;
  transition: all var(--transition-fast);
}

.form-input:focus,
.form-textarea:focus {
  outline: none;
  border-color: var(--color-accent);
  box-shadow: 0 0 0 3px rgba(234, 88, 12, 0.1);
}

.form-textarea {
  min-height: 150px;
  resize: vertical;
}

.form-error {
  display: none;
  font-size: var(--text-sm);
  color: #dc2626;
  margin-top: var(--space-xs);
}

.form-error.active {
  display: block;
}

.form-input.error,
.form-textarea.error {
  border-color: #dc2626;
}

.form-success {
  display: none;
  padding: var(--space-lg);
  background-color: #dcfce7;
  color: #166534;
  border-radius: 6px;
  margin-bottom: var(--space-xl);
  text-align: center;
}

[data-theme="dark"] .form-success {
  background-color: #14532d;
  color: #86efac;
}

.form-success.active {
  display: block;
  animation: fadeInUp 0.5s ease;
}

/* ========================================
   FOOTER
   ======================================== */
.footer {
  border-top: 1px solid var(--color-border);
  padding: var(--space-3xl) 0;
  margin-top: var(--space-4xl);
}

.footer-content {
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: var(--space-lg);
}

.footer-text {
  color: var(--color-text-muted);
  font-size: var(--text-sm);
}

.social-links {
  display: flex;
  gap: var(--space-lg);
  list-style: none;
}

.social-link {
  color: var(--color-text-muted);
  transition: color var(--transition-fast);
  font-size: var(--text-lg);
}

.social-link:hover {
  color: var(--color-accent);
}

/* ========================================
   UTILITIES
   ======================================== */
.section {
  padding: var(--space-4xl) 0;
}

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

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

.mb-0 { margin-bottom: 0; }
.mb-sm { margin-bottom: var(--space-sm); }
.mb-md { margin-bottom: var(--space-md); }
.mb-lg { margin-bottom: var(--space-lg); }
.mb-xl { margin-bottom: var(--space-xl); }

.mt-0 { margin-top: 0; }
.mt-sm { margin-top: var(--space-sm); }
.mt-md { margin-top: var(--space-md); }
.mt-lg { margin-top: var(--space-lg); }
.mt-xl { margin-top: var(--space-xl); }

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

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

/* ========================================
   RESPONSIVE DESIGN
   ======================================== */

/* Tablet */
@media (max-width: 768px) {
  :root {
    --text-5xl: 2.5rem;
    --text-4xl: 2rem;
    --text-3xl: 1.5rem;
  }
  
  .nav-container {
    padding: var(--space-md) var(--space-lg);
  }
  
  .nav-menu {
    gap: var(--space-lg);
  }
  
  .hero {
    min-height: 70vh;
    padding: var(--space-3xl) 0;
  }
  
  .blog-grid {
    grid-template-columns: 1fr;
  }
  
  .footer-content {
    flex-direction: column;
    text-align: center;
  }
}

/* Mobile */
@media (max-width: 480px) {
  :root {
    --space-xl: 1.5rem;
    --space-2xl: 2rem;
    --space-3xl: 3rem;
    --space-4xl: 4rem;
  }
  
  .nav-menu {
    gap: var(--space-md);
  }
  
  .nav-link {
    font-size: var(--text-xs);
  }
  
  .hero-subtitle {
    font-size: var(--text-xl);
  }
  
  .hero-description {
    font-size: var(--text-base);
  }
  
  .card {
    padding: var(--space-lg);
  }
  
  .btn {
    width: 100%;
  }
}

/* ========================================
   PRINT STYLES
   ======================================== */
@media print {
  .header,
  .footer,
  .theme-toggle,
  .btn {
    display: none;
  }
  
  body {
    color: #000;
    background: #fff;
  }
}