/* CSS Variables */
:root {
    /* Colors */
    --primary-color: #2c3e50;
    --secondary-color: #34495e;
    --accent-color: #0056b3;
    --text-primary: #2c3e50;
    --text-secondary: #666;
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --border-color: #eaeaea;
    --card-bg: #ffffff;
    --shadow-sm: 0 2px 4px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 8px rgba(0, 0, 0, 0.15);
    --shadow-lg: 0 4px 12px rgba(0, 0, 0, 0.2);
    
    /* Spacing */
    --spacing-xs: 5px;
    --spacing-sm: 10px;
    --spacing-md: 15px;
    --spacing-lg: 20px;
    --spacing-xl: 30px;
    
    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    
    /* Transitions */
    --transition-default: all 0.3s ease;
}

/* Dark Theme Variables */
[data-theme="dark"] {
    --primary-color: #66b3ff;
    --secondary-color: #505050;
    --accent-color: #66b3ff;
    --text-primary: #e0e0e0;
    --text-secondary: #b0b0b0;
    --bg-primary: #1a1a1a;
    --bg-secondary: #2d2d2d;
    --border-color: #404040;
    --card-bg: rgba(255, 255, 255, 0.05);
}

/* Base Styles */
body {
    font-family: 'Arial', sans-serif;
    max-width: 1000px;
    margin: 0 auto;
    padding: var(--spacing-lg);
    line-height: 1.6;
    background-color: var(--bg-primary);
    color: var(--text-primary);
}

/* Typography */
h1, h2, h3 {
    color: var(--text-primary);
}

h2 {
    font-size: 1.8em;
    margin-top: var(--spacing-md);
    margin-bottom: var(--spacing-sm);
    padding-bottom: var(--spacing-sm);
    border-bottom: 2px solid var(--border-color);
    position: relative;
    display: inline-block;
}

h2::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 100%;
    height: 2px;
    background-color: var(--primary-color);
}

h3 {
    font-size: 1.4em;
    margin-top: 25px;
    margin-bottom: var(--spacing-md);
    padding-left: var(--spacing-md);
    border-left: 4px solid var(--primary-color);
}

/* Layout Components */
.header {
    display: flex;
    align-items: center;
    gap: var(--spacing-xl);
    margin-bottom: 40px;
}

.section {
    margin-bottom: var(--spacing-xl);
}

/* Profile Image */
.profile-img {
    width: 200px;
    height: auto;
    border-radius: var(--radius-md);
    box-shadow: var(--shadow-sm);
}

/* Controls */
.controls {
    position: fixed;
    top: var(--spacing-lg);
    right: var(--spacing-lg);
    z-index: 1000;
    display: flex;
    gap: var(--spacing-sm);
    align-items: center;
}

/* Language Switch */
.language-switch {
    text-align: right;
    margin-bottom: var(--spacing-lg);
}

.language-btn {
    display: inline-block;
    padding: 8px 16px;
    background-color: var(--primary-color);
    color: white;
    text-decoration: none;
    border-radius: var(--radius-sm);
    transition: var(--transition-default);
}

.language-btn:hover {
    background-color: var(--secondary-color);
}

/* Theme Switch */
.theme-switch {
    position: static;
    margin: 0;
    width: 40px;
    height: 40px;
    background: none;
    border: none;
    cursor: pointer;
    font-size: 24px;
    padding: 8px;
    border-radius: 50%;
    background-color: var(--primary-color);
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* Table of Contents */
.toc {
    position: fixed;
    left: var(--spacing-lg);
    top: 50%;
    transform: translateY(-50%);
    width: 140px;
    background-color: var(--card-bg);
    padding: 25px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    max-height: 80vh;
    overflow-y: auto;
    border: 1px solid var(--border-color);
    transition: var(--transition-default);
}

.toc ul {
    list-style: none;
    padding-left: 0;
    margin: 0;
}

.toc ul ul {
    padding-left: 16px;
    margin: var(--spacing-sm) 0;
    border-left: 2px solid var(--border-color);
}

.toc li {
    margin-bottom: var(--spacing-sm);
    line-height: 1.3;
}

.toc li li {
    margin-bottom: 6px;
}

.toc a {
    color: var(--text-primary);
    text-decoration: none;
    font-size: 18px;
    transition: var(--transition-default);
    display: block;
    padding: 3px 6px;
    border-radius: var(--radius-sm);
    position: relative;
    overflow: hidden;
    text-align: center;
}

.toc a:hover {
    color: var(--accent-color);
    background-color: var(--bg-secondary);
    transform: translateX(4px);
}

/* Scrollbar Styles */
.toc::-webkit-scrollbar {
    width: 6px;
}

.toc::-webkit-scrollbar-track {
    background: transparent;
}

.toc::-webkit-scrollbar-thumb {
    background-color: var(--border-color);
    border-radius: 3px;
}

/* Publication Styles */
.publication {
    margin-bottom: 0;
    padding: var(--spacing-xs) var(--spacing-sm) var(--spacing-xs) var(--spacing-sm);
    border-bottom: 1px solid var(--border-color);
    transition: var(--transition-default);
    border-left: 3px solid transparent;
    cursor: pointer;
}

.publication:hover {
    background-color: var(--bg-secondary);
    border-left-color: var(--primary-color);
    padding-left: var(--spacing-md);
    transform: translateX(5px);
}

.publication:last-child {
    border-bottom: none;
}

.journal-tag {
    display: inline-block;
    padding: 2px 8px;
    margin-left: 8px;
    font-size: 0.8em;
    border-radius: var(--radius-sm);
    background-color: var(--primary-color);
    color: white;
    font-weight: 500;
}

[data-theme="dark"] .journal-tag {
    background-color: var(--accent-color);
    color: var(--bg-primary);
}

.paper-title {
    font-weight: 500;
    margin: var(--spacing-xs) 0;
    font-size: 1.05em;
}

.authors {
    margin: 3px 0;
    color: var(--text-secondary);
}

.journal {
    font-size: 0.95em;
    margin: 3px 0;
    color: var(--text-secondary);
}

/* Date Styles */
.date {
    display: inline-block;
    width: 220px;
    vertical-align: top;
}

.date-compact {
    display: inline-block;
    width: 120px;
    vertical-align: top;
}

/* Card Components */
.education-cards,
.experience-cards {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-lg);
    margin-top: var(--spacing-lg);
}

.education-card,
.experience-card,
.intro-section {
    background: var(--card-bg);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
    transition: var(--transition-default);
}

.education-card:hover,
.experience-card:hover,
.intro-section:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.education-header,
.experience-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: var(--spacing-sm);
}

.education-header .date,
.experience-header .date {
    color: var(--text-secondary);
    font-size: 0.9em;
    width: auto;
}

.education-header .degree,
.experience-header .company {
    font-weight: bold;
    color: var(--text-primary);
}

.experience-header .company {
    text-align: right;
}

.institution,
.department {
    font-weight: 500;
    color: var(--text-primary);
    margin-bottom: var(--spacing-sm);
    font-size: 0.95em;
}

.details {
    color: var(--text-secondary);
    font-size: 0.95em;
}

.details p {
    margin: var(--spacing-sm) 0;
    line-height: 1.5;
}

/* Experience Item Styles */
.experience-item {
    display: flex;
    margin-bottom: 10px;
}

.experience-content {
    flex: 1;
}

/* Links */
.intro-section a {
    color: var(--text-primary);
    text-decoration: none;
    transition: var(--transition-default);
}

.intro-section a:hover {
    opacity: 0.8;
}

/* Language-specific Styles */
html[lang="zh"] body {
    font-family: 'Microsoft YaHei', sans-serif;
}

/* Introduction Section */
.intro-section {
    background: var(--card-bg);
    border-radius: 16px;
    padding: 30px;
    box-shadow: 0 2px 12px rgba(0, 0, 0, 0.06);
    margin: 20px 0;
    border: 1px solid rgba(0, 0, 0, 0.08);
    transition: var(--transition-default);
}

.intro-section p {
    font-size: 1.05em;
    line-height: 1.8;
    color: var(--text-primary);
    margin: 0;
}

.intro-section a {
    color: var(--text-primary);
    text-decoration: none;
    border-bottom: 2px solid var(--text-primary);
    transition: var(--transition-default);
    padding-bottom: 2px;
}

.intro-section a:hover {
    color: var(--secondary-color);
    border-bottom-color: transparent;
}

/* List Styles */
.section ul {
    list-style: none;
    padding-left: 0;
}

/* Publications */
.publications-note {
    font-size: 0.9em;
    color: var(--text-secondary);
    margin-top: -10px;
    margin-bottom: 20px;
}

/* Responsive Styles */
@media (max-width: 1440px) {
    .toc {
        left: var(--spacing-lg);
    }
}

@media (max-width: 1200px) {
    .toc {
        display: none;
    }
    
    body {
        padding: var(--spacing-lg);
    }
}

@media (max-width: 768px) {
    .header {
        flex-direction: column;
        text-align: center;
        gap: var(--spacing-md);
    }
    
    .profile-img {
        width: 150px;
    }
}

@media (max-width: 480px) {
    .profile-img {
        width: 120px;
    }
}

/* Dark Theme Styles */
[data-theme="dark"] {
    background-color: var(--bg-primary);
    color: var(--text-primary);
}

[data-theme="dark"] h1, 
[data-theme="dark"] h2,
[data-theme="dark"] h3 {
    color: var(--text-primary);
}

[data-theme="dark"] a {
    color: var(--accent-color);
}

[data-theme="dark"] .language-btn {
    background-color: var(--primary-color);
    border: 1px solid transparent;
    color: var(--bg-primary);
}

[data-theme="dark"] .language-btn:hover {
    background-color: var(--bg-secondary);
    border-color: var(--primary-color);
    color: var(--primary-color);
    transform: translateY(-2px);
    box-shadow: var(--shadow-sm);
}

[data-theme="dark"] .theme-switch {
    background-color: var(--secondary-color);
}

[data-theme="dark"] .toc {
    background-color: var(--card-bg);
    border-color: var(--border-color);
    box-shadow: var(--shadow-md);
}

[data-theme="dark"] .toc ul ul {
    border-left-color: var(--border-color);
}

[data-theme="dark"] .toc a {
    color: var(--text-primary);
}

[data-theme="dark"] .toc a:hover {
    color: var(--accent-color);
    background-color: var(--bg-secondary);
}

[data-theme="dark"] .publication {
    border-bottom-color: var(--border-color);
}

[data-theme="dark"] .publication:hover {
    background-color: var(--bg-secondary);
    border-left-color: var(--primary-color);
}

[data-theme="dark"] .paper-title {
    color: var(--text-primary);
}

[data-theme="dark"] .authors {
    color: var(--text-secondary);
}

[data-theme="dark"] .journal {
    color: var(--text-secondary);
}

[data-theme="dark"] .education-card,
[data-theme="dark"] .experience-card,
[data-theme="dark"] .intro-section {
    background: var(--card-bg);
    border-color: var(--border-color);
}

[data-theme="dark"] .education-card:hover,
[data-theme="dark"] .experience-card:hover,
[data-theme="dark"] .intro-section:hover {
    box-shadow: var(--shadow-lg);
}

[data-theme="dark"] .education-header .date,
[data-theme="dark"] .experience-header .date {
    color: var(--text-secondary);
}

[data-theme="dark"] .education-header .degree,
[data-theme="dark"] .experience-header .company {
    color: var(--text-primary);
}

[data-theme="dark"] .institution,
[data-theme="dark"] .department {
    color: var(--text-primary);
}

[data-theme="dark"] .details {
    color: var(--text-secondary);
}

[data-theme="dark"] .intro-section a {
    color: var(--accent-color);
}

[data-theme="dark"] .intro-section a:hover {
    color: var(--primary-color);
}

[data-theme="dark"] .intro-section {
    background: var(--card-bg);
    border-color: var(--border-color);
    box-shadow: var(--shadow-lg);
}

[data-theme="dark"] .intro-section p {
    color: var(--text-primary);
}

[data-theme="dark"] .intro-section a {
    color: var(--accent-color);
    border-bottom-color: var(--accent-color);
}

[data-theme="dark"] .intro-section a:hover {
    color: var(--primary-color);
}