/* Modern CSS Stylesheet for Lei Wang's Website */

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

:root {
    /* Modern Color Palette */
    --primary-color: #2c3e50;
    --secondary-color: #3498db;
    --accent-color: #e74c3c;
    --text-color: #333;
    --text-light: #666;
    --bg-color: #ffffff;
    --bg-secondary: #f8f9fa;
    --border-color: #e1e4e8;
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-hover: 0 4px 16px rgba(0, 0, 0, 0.15);
    
    /* Typography */
    --font-primary: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Roboto', 'Oxygen', 'Ubuntu', 'Cantarell', 'Fira Sans', 'Droid Sans', 'Helvetica Neue', sans-serif;
    --font-serif: 'Georgia', 'Times New Roman', serif;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2.5rem;
    --spacing-xl: 4rem;
    
    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    
    /* Transitions */
    --transition: all 0.3s ease;
}

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

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

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

.container-narrow {
    max-width: 900px;
    margin: 0 auto;
    padding: var(--spacing-lg) var(--spacing-md);
}

/* Header Styles */
header {
    background: linear-gradient(135deg, var(--primary-color) 0%, #34495e 100%);
    color: white;
    padding: var(--spacing-lg) 0;
    box-shadow: var(--shadow);
}

.hero {
    text-align: center;
    padding: var(--spacing-xl) var(--spacing-md);
}

.hero h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    letter-spacing: -0.5px;
    color: white;
}

.hero h2 {
    font-size: 1.25rem;
    font-weight: 400;
    margin-bottom: var(--spacing-lg);
    opacity: 0.95;
}

.profile-description {
    color: #e8f4f8 !important;
    text-shadow: 0 1px 2px rgba(0, 0, 0, 0.2);
}

.profile-image {
    max-width: 400px;
    width: 100%;
    height: auto;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-hover);
    margin: var(--spacing-lg) auto;
    display: block;
    transition: var(--transition);
}

.profile-image:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.2);
}

/* Responsive image sizing */
@media (max-width: 768px) {
    .profile-image {
        max-width: 300px;
    }
}

@media (max-width: 480px) {
    .profile-image {
        max-width: 250px;
    }
}

/* Navigation Links */
.nav-links {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: var(--spacing-md);
    margin-top: var(--spacing-lg);
}

.nav-links a {
    color: white;
    text-decoration: none;
    font-weight: 500;
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-sm);
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    transition: var(--transition);
    border: 1px solid rgba(255, 255, 255, 0.2);
}

.nav-links a:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: translateY(-2px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
}

/* Main Content */
main {
    min-height: 60vh;
}

/* Typography in Content */
h1, h2, h3, h4, h5, h6 {
    color: var(--primary-color);
    font-weight: 600;
    line-height: 1.3;
    margin-bottom: var(--spacing-sm);
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }

/* Links in Content */
a {
    color: var(--secondary-color);
    text-decoration: none;
    transition: var(--transition);
    position: relative;
}

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

main a:not(.nav-links a) {
    border-bottom: 1px solid transparent;
}

main a:not(.nav-links a):hover {
    border-bottom: 1px solid currentColor;
}

/* Content Lists */
.content-list {
    list-style: none;
    padding: 0;
}

.content-list li {
    background: var(--bg-secondary);
    padding: var(--spacing-md);
    margin-bottom: var(--spacing-sm);
    border-radius: var(--radius-md);
    border-left: 4px solid var(--secondary-color);
    transition: var(--transition);
}

.content-list li:hover {
    transform: translateX(4px);
    box-shadow: var(--shadow);
    border-left-color: var(--accent-color);
}

.content-list h2 {
    font-size: 1.125rem;
    margin: 0;
    line-height: 1.5;
}

.content-list a {
    display: block;
    color: var(--text-color);
}

.content-list a:hover {
    color: var(--secondary-color);
}

/* Cards */
.card {
    background: white;
    border-radius: var(--radius-md);
    padding: var(--spacing-lg);
    margin-bottom: var(--spacing-md);
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.card:hover {
    box-shadow: var(--shadow-hover);
    transform: translateY(-2px);
}

/* Footer */
footer {
    background: var(--bg-secondary);
    padding: var(--spacing-md) 0;
    margin-top: var(--spacing-lg);
    border-top: 1px solid var(--border-color);
    text-align: center;
    color: var(--text-light);
    font-size: 0.875rem;
}

/* Hit Counter */
.hit-counter {
    display: none;
    text-align: center;
    padding: var(--spacing-md);
    margin-top: var(--spacing-lg);
}

/* Responsive Design */
@media (max-width: 768px) {
    :root {
        --spacing-lg: 1.5rem;
        --spacing-xl: 2.5rem;
    }
    
    .hero h1 {
        font-size: 1.875rem;
    }
    
    .hero h2 {
        font-size: 1.125rem;
    }
    
    .nav-links {
        gap: var(--spacing-sm);
    }
    
    .nav-links a {
        font-size: 0.875rem;
        padding: var(--spacing-xs) var(--spacing-sm);
    }
    
    .container,
    .container-narrow {
        padding: var(--spacing-md) var(--spacing-sm);
    }
    
    h1 { font-size: 1.875rem; }
    h2 { font-size: 1.5rem; }
    h3 { font-size: 1.25rem; }
}

@media (max-width: 480px) {
    .hero h1 {
        font-size: 1.5rem;
    }
    
    .nav-links {
        flex-direction: column;
        gap: var(--spacing-xs);
    }
    
    .nav-links a {
        width: 100%;
        text-align: center;
    }
}

/* Print Styles */
@media print {
    header {
        background: none;
        color: black;
        box-shadow: none;
    }
    
    .nav-links a {
        background: none;
        color: black;
        border: 1px solid black;
    }
    
    .hit-counter {
        display: none;
    }
}

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

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

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

/* Loading States */
img {
    max-width: 100%;
    height: auto;
}

/* Selection Color */
::selection {
    background-color: var(--secondary-color);
    color: white;
}

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

/* Loading and Error States */
.loading {
    text-align: center;
    padding: var(--spacing-xl);
    color: var(--text-light);
    font-size: 1.125rem;
}

.loading::after {
    content: '...';
    animation: loadingDots 1.5s infinite;
}

@keyframes loadingDots {
    0%, 20% { content: '.'; }
    40% { content: '..'; }
    60%, 100% { content: '...'; }
}

.error-message {
    background: #fee;
    border: 1px solid #fcc;
    border-radius: var(--radius-md);
    padding: var(--spacing-lg);
    margin: var(--spacing-lg) 0;
    text-align: center;
}

.error-message h2 {
    color: var(--accent-color);
    margin-bottom: var(--spacing-sm);
}

/* Markdown Content Styling */
#markdown-content h2 {
    margin-top: var(--spacing-lg);
    padding-bottom: var(--spacing-xs);
    border-bottom: 2px solid var(--border-color);
}

#markdown-content h3 {
    margin-top: var(--spacing-md);
    color: var(--text-color);
}

#markdown-content ul:not(.content-list) {
    margin-left: var(--spacing-md);
}

#markdown-content ul:not(.content-list) li {
    margin-bottom: var(--spacing-xs);
}

/* Supplementary Links Styling (links in brackets) */
#markdown-content .content-list li {
    line-height: 1.8;
}

/* Main title links - keep normal */
#markdown-content .content-list li a:first-of-type {
    display: inline;
    color: var(--text-color);
    background: none;
}

#markdown-content .content-list li a:first-of-type:hover {
    color: var(--secondary-color);
    background: none;
}

/* Style supplementary links (after the first link) as badges */
#markdown-content .content-list li a:not(:first-of-type) {
    display: inline-block;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white !important;
    padding: 0.2em 0.6em;
    border-radius: 4px;
    font-size: 0.85em;
    margin: 0.2em 0.3em;
    transition: var(--transition);
    border: none !important;
    text-decoration: none;
    font-weight: 500;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

#markdown-content .content-list li a:not(:first-of-type):hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.2);
    background: linear-gradient(135deg, #764ba2 0%, #667eea 100%);
}

/* Different colors for different types of supplementary links */
#markdown-content .content-list li a:not(:first-of-type)[href*="github"] {
    background: linear-gradient(135deg, #24292e 0%, #4a5568 100%);
}

#markdown-content .content-list li a:not(:first-of-type)[href*="youtube"],
#markdown-content .content-list li a:not(:first-of-type)[href*="bilibili"],
#markdown-content .content-list li a:not(:first-of-type)[href*="koushare"] {
    background: linear-gradient(135deg, #e74c3c 0%, #c0392b 100%);
}

#markdown-content .content-list li a:not(:first-of-type)[href$=".pdf"] {
    background: linear-gradient(135deg, #3498db 0%, #2980b9 100%);
}

/* Add icons using pseudo-elements - only to supplementary links */
#markdown-content .content-list li a:not(:first-of-type)[href*="github"]:before {
    content: "📦 ";
}

#markdown-content .content-list li a:not(:first-of-type)[href*="youtube"]:before,
#markdown-content .content-list li a:not(:first-of-type)[href*="bilibili"]:before,
#markdown-content .content-list li a:not(:first-of-type)[href*="koushare"]:before {
    content: "📹 ";
}

#markdown-content .content-list li a:not(:first-of-type)[href$=".pdf"]:before {
    content: "📄 ";
}