/* 
 * Main CSS for Yang Li's GitHub Pages
 * Python programming style with code editor aesthetics
 */

/* Import Python Theme */
@import url('python-theme.css');

/* ===== Variables ===== */
:root {
  /* Light theme (default) */
  --color-background: var(--bg-color);
  --color-text-primary: var(--text-color);
  --color-text-secondary: var(--comment-color);
  --color-accent: var(--function-color);
  --color-accent-hover: var(--constant-color);
  --color-border: var(--card-border);
  --color-background-secondary: var(--card-bg);
  
  /* Typography */
  --font-primary: var(--code-font);
  --font-display: var(--code-font);
  
  /* Spacing */
  --spacing-xs: 0.5rem;
  --spacing-sm: 1rem;
  --spacing-md: 2rem;
  --spacing-lg: 3rem;
  --spacing-xl: 5rem;
  
  /* Container width */
  --container-width: 1000px;
  --container-padding: 1.5rem;
}

/* Dark theme */
[data-theme="dark"] {
  --color-background: var(--bg-color);
  --color-text-primary: var(--text-color);
  --color-text-secondary: var(--comment-color);
  --color-accent: var(--function-color);
  --color-accent-hover: var(--constant-color);
  --color-border: var(--card-border);
  --color-background-secondary: var(--card-bg);
}

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

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

body {
  font-family: var(--font-primary);
  line-height: 1.5;
  color: var(--color-text-primary);
  background-color: var(--color-background);
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

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

a {
  color: var(--color-accent);
  text-decoration: none;
  transition: color 0.2s ease;
}

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

/* ===== Layout ===== */
.container {
  max-width: var(--container-width);
  margin: 0 auto;
  padding: 0 var(--container-padding);
}

.header {
  padding: var(--spacing-md) 0;
  border-bottom: 1px solid var(--color-border);
}

.content {
  padding: var(--spacing-lg) 0;
}

.footer {
  padding: var(--spacing-md) 0;
  border-top: 1px solid var(--color-border);
  color: var(--color-text-secondary);
  font-size: 0.9rem;
}

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

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

h1 {
  font-size: 2.5rem;
  letter-spacing: -0.02em;
}

h2 {
  font-size: 2rem;
  letter-spacing: -0.01em;
  margin-top: var(--spacing-lg);
}

h3 {
  font-size: 1.5rem;
  margin-top: var(--spacing-md);
}

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

/* ===== Navigation ===== */
.nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.nav-logo {
  font-weight: 600;
  font-size: 1.25rem;
  color: var(--color-text-primary);
  display: flex;
  align-items: center;
  gap: 0.5rem;
}

.nav-links {
  display: flex;
  gap: var(--spacing-md);
  list-style: none;
}

/* Theme Toggle */
.theme-toggle {
  margin-left: var(--spacing-md);
  display: flex;
  align-items: center;
}

#theme-toggle-btn {
  background: none;
  border: none;
  cursor: pointer;
  color: var(--color-text-primary);
  font-size: 1.2rem;
  padding: 0.5rem;
  border-radius: 50%;
  transition: all 0.2s ease;
  display: flex;
  align-items: center;
  justify-content: center;
}

#theme-toggle-btn:hover {
  background-color: var(--color-background-secondary);
  transform: translateY(-2px);
}

.nav-link {
  color: var(--color-text-primary);
  font-weight: 500;
  transition: color 0.2s ease;
}

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

/* Mobile Navigation Toggle */
.nav-toggle {
  display: none;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.5rem;
  z-index: 100;
}

.nav-toggle span {
  display: block;
  width: 24px;
  height: 2px;
  margin: 5px 0;
  background-color: var(--color-text-primary);
  transition: transform 0.3s ease, opacity 0.3s ease;
}

.nav-toggle.active span:nth-child(1) {
  transform: translateY(7px) rotate(45deg);
}

.nav-toggle.active span:nth-child(2) {
  opacity: 0;
}

.nav-toggle.active span:nth-child(3) {
  transform: translateY(-7px) rotate(-45deg);
}

/* ===== Hero Section ===== */
.hero-compact {
  padding: var(--spacing-md) 0;
  text-align: left;
}

.hero-content {
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
}

.hero-text {
  max-width: 60%;
}

.hero-compact h1 {
  font-size: 2.2rem;
  margin-bottom: var(--spacing-xs);
  line-height: 1.1;
}

.hero-subtitle {
  font-size: 1rem;
  color: var(--color-text-secondary);
  margin: 0;
}

/* ===== Social Icons ===== */
.social-icons {
  display: flex;
  gap: var(--spacing-xs);
  margin: var(--spacing-xs) 0;
}

.social-icons a {
  color: var(--color-text-secondary);
  font-size: 1.2rem;
  transition: color 0.2s ease, transform 0.2s ease;
}

.social-icons a:hover {
  color: var(--color-accent);
  transform: translateY(-2px);
}

/* ===== Navigation Social Icons ===== */
.nav-social-icons {
  display: flex;
  gap: var(--spacing-xs);
  margin-left: auto;
  margin-right: var(--spacing-sm);
}

.nav-social-icons a {
  color: var(--color-text-secondary);
  font-size: 1.2rem;
  transition: color 0.2s ease, transform 0.2s ease;
  padding: 0.25rem;
}

.nav-social-icons a:hover {
  color: var(--color-accent);
  transform: translateY(-2px);
}



/* ===== Cards ===== */
.card {
  background-color: var(--color-background);
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.05);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
  margin-bottom: var(--spacing-md);
}

.card:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.1);
}

.card-content {
  padding: var(--spacing-md);
}

/* ===== Buttons ===== */
.button {
  display: inline-block;
  background-color: var(--color-accent);
  color: white;
  padding: 0.75rem 1.5rem;
  border-radius: 8px;
  font-weight: 500;
  transition: background-color 0.2s ease, transform 0.2s ease;
}

.button:hover {
  background-color: var(--color-accent-hover);
  color: white;
  transform: translateY(-2px);
}

.button-secondary {
  background-color: var(--color-background-secondary);
  color: var(--color-text-primary);
}

.button-secondary:hover {
  background-color: var(--color-border);
  color: var(--color-text-primary);
}

/* ===== Animations ===== */
.fade-in {
  animation: fadeIn 0.8s ease forwards;
}

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

.animate-on-scroll {
  opacity: 0;
  transform: translateY(30px);
  transition: opacity 0.8s ease, transform 0.8s ease;
}

.animate-on-scroll.animated {
  opacity: 1;
  transform: translateY(0);
}

/* ===== Responsive Design ===== */
@media (max-width: 768px) {
  :root {
    --container-padding: 1rem;
  }
  
  h1 {
    font-size: 2rem;
  }
  
  h2 {
    font-size: 1.5rem;
  }
  
  .hero-compact h1 {
    font-size: 1.8rem;
  }
  
  .hero-subtitle {
    font-size: 0.9rem;
  }
  
  .hero-content {
    flex-direction: column;
    align-items: flex-start;
  }
  
  .hero-text {
    max-width: 100%;
    margin-bottom: var(--spacing-xs);
  }
  
  /* Mobile Navigation */
  .nav {
    position: relative;
  }
  
  .nav-toggle {
    display: block;
  }
  
  .nav-links {
    position: fixed;
    top: 0;
    right: -100%;
    width: 70%;
    height: 100vh;
    background-color: var(--color-background);
    flex-direction: column;
    padding: 80px 2rem 2rem;
    transition: right 0.3s ease;
    box-shadow: -5px 0 15px rgba(0, 0, 0, 0.1);
    z-index: 90;
  }
  
  .nav-links.active {
    right: 0;
  }
  
  .nav-links li {
    margin-bottom: var(--spacing-md);
  }
}

@media (max-width: 480px) {
  html {
    font-size: 14px;
  }
  
  .hero {
    padding: var(--spacing-lg) 0;
  }
  
  .social-icons {
    flex-wrap: wrap;
  }
}

/* ===== Section Header ===== */
.section-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: var(--spacing-md);
}

.section-link {
  font-weight: 500;
  font-size: 0.9rem;
}



.featured-label {
  display: inline-block;
  background-color: var(--color-accent);
  color: white;
  font-size: 0.8rem;
  font-weight: 500;
  padding: 0.25rem 0.5rem;
  border-radius: 4px;
  margin-bottom: var(--spacing-xs);
}



/* ===== Multi-column Layout ===== */
.content-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--spacing-md);
  margin-top: var(--spacing-lg);
}

.content-grid-item {
  background-color: var(--color-background);
  border-radius: 12px;
  overflow: hidden;
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.05);
  border: 1px solid var(--color-border);
  transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.content-grid-item:hover {
  transform: translateY(-5px);
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.1);
}

.content-grid-content {
  padding: var(--spacing-md);
}

.content-grid-title {
  font-size: 1.2rem;
  margin-bottom: var(--spacing-xs);
}

.content-grid-meta {
  font-size: 0.8rem;
  color: var(--color-text-secondary);
  margin-bottom: var(--spacing-xs);
}

/* Media queries for responsiveness */
@media (max-width: 768px) {
  .section-header {
    flex-direction: column;
    align-items: flex-start;
    gap: var(--spacing-xs);
  }
  

}