/* ==========================================
   CSS Variables & Themes
   ========================================== */
:root {
    /* Light Theme (default) */
    --bg-primary: #ffffff;
    --bg-secondary: #f8f9fa;
    --bg-tertiary: #e9ecef;
    --text-primary: #212529;
    --text-secondary: #6c757d;
    --accent: #0066cc;
    --accent-hover: #0052a3;
    --border: #dee2e6;
    --shadow: rgba(0, 0, 0, 0.1);
    --card-bg: #ffffff;

    /* Layout */
    --max-width: 900px;
    --nav-height: 60px;
    --section-gap: 80px;
    --border-radius: 8px;
    --border-radius-lg: 12px;

    /* Transitions */
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s ease;
}

/* Dark Theme */
[data-theme="dark"] {
    --bg-primary: #121212;
    --bg-secondary: #1e1e1e;
    --bg-tertiary: #2d2d2d;
    --text-primary: #e0e0e0;
    --text-secondary: #a0a0a0;
    --accent: #4da6ff;
    --accent-hover: #7bbfff;
    --border: #333333;
    --shadow: rgba(0, 0, 0, 0.3);
    --card-bg: #1e1e1e;
}

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: var(--nav-height);
}

body {
    font-family: 'Inter', 'Noto Sans SC', 'PingFang SC', 'Microsoft YaHei', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    transition: background-color var(--transition-normal), color var(--transition-normal);
}

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

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

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

/* ==========================================
   Container
   ========================================== */
.container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
}

/* ==========================================
   Navigation
   ========================================== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--nav-height);
    background-color: var(--bg-primary);
    border-bottom: 1px solid var(--border);
    z-index: 1000;
    transition: background-color var(--transition-normal), border-color var(--transition-normal);
}

.nav-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
}

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

.nav-menu {
    display: flex;
    list-style: none;
    gap: 32px;
}

.nav-link {
    color: var(--text-secondary);
    font-size: 0.95rem;
    font-weight: 500;
    padding: 8px 0;
    position: relative;
}

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

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

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

.nav-controls {
    display: flex;
    align-items: center;
    gap: 12px;
}

.theme-toggle,
.lang-toggle {
    background: none;
    border: 1px solid var(--border);
    border-radius: var(--border-radius);
    padding: 8px 12px;
    cursor: pointer;
    color: var(--text-primary);
    font-size: 0.9rem;
    font-weight: 500;
    transition: all var(--transition-fast);
}

.theme-toggle:hover,
.lang-toggle:hover {
    background-color: var(--bg-secondary);
    border-color: var(--accent);
}

.nav-hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
}

.nav-hamburger span {
    width: 24px;
    height: 2px;
    background-color: var(--text-primary);
    transition: all var(--transition-fast);
}

/* ==========================================
   Main Content
   ========================================== */
.main-content {
    padding-top: var(--nav-height);
}

.section {
    padding: var(--section-gap) 0;
}

.section-title {
    font-size: 1.75rem;
    font-weight: 600;
    margin-bottom: 40px;
    color: var(--text-primary);
    position: relative;
    display: inline-block;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -8px;
    left: 0;
    width: 40px;
    height: 3px;
    background-color: var(--accent);
    border-radius: 2px;
}

/* ==========================================
   Home Section
   ========================================== */
.section-home {
    min-height: calc(100vh - var(--nav-height));
    display: flex;
    align-items: center;
}

.home-content {
    display: flex;
    gap: 48px;
    align-items: flex-start;
}

.home-avatar-container {
    flex-shrink: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 16px;
    width: 200px;
}

.home-avatar {
    flex-shrink: 0;
}

.home-avatar img {
    width: 200px;
    height: 200px;
    border-radius: 50%;
    object-fit: cover;
    border: 4px solid var(--border);
    transition: border-color var(--transition-normal);
}

.wakatime-chart {
    width: 200px;
    overflow: hidden;
    border-radius: var(--border-radius);
}

.wakatime-chart embed {
    width: auto;
    height: 150px;
    display: block;
    animation: scroll-left 20s linear infinite;
}

@keyframes scroll-left {
    0% {
        transform: translateX(0);
    }
    50% {
        transform: translateX(calc(-100% + 200px));
    }
    100% {
        transform: translateX(0);
    }
}

.home-social {
    display: flex;
    flex-direction: column;
    gap: 8px;
    width: 100%;
}

.social-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 8px 12px;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--border-radius);
    color: var(--text-primary);
    font-size: 0.85rem;
    font-weight: 500;
    transition: all var(--transition-fast);
}

.social-link:hover {
    background-color: var(--accent);
    border-color: var(--accent);
    color: #ffffff;
}

.social-link i {
    font-size: 1rem;
}

.home-info {
    flex: 1;
}

.home-name {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.home-title {
    font-size: 1.25rem;
    color: var(--accent);
    font-weight: 500;
    margin-bottom: 4px;
}

.home-affiliation {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 24px;
}

.home-bio {
    font-size: 1rem;
    line-height: 1.8;
    color: var(--text-primary);
    margin-bottom: 24px;
}

.home-bio p {
    margin-bottom: 12px;
}

.home-bio strong {
    color: var(--accent);
}

.home-cv {
    margin-bottom: 16px;
}

.cv-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 20px;
    background-color: var(--accent);
    color: #ffffff;
    border-radius: var(--border-radius);
    font-size: 0.95rem;
    font-weight: 500;
    transition: background-color var(--transition-fast);
}

.cv-link:hover {
    background-color: var(--accent-hover);
    color: #ffffff;
}

.home-social {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
}

.social-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 10px 16px;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--border-radius);
    color: var(--text-primary);
    font-size: 0.9rem;
    font-weight: 500;
    transition: all var(--transition-fast);
}

.social-link:hover {
    background-color: var(--accent);
    border-color: var(--accent);
    color: #ffffff;
}

.social-link i {
    font-size: 1.1rem;
}

/* ==========================================
   News Section
   ========================================== */
.news-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.news-item {
    display: flex;
    gap: 16px;
    padding: 16px;
    background-color: var(--bg-secondary);
    border-radius: var(--border-radius);
    border-left: 3px solid var(--accent);
}

.news-date {
    flex-shrink: 0;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--accent);
    min-width: 80px;
}

.news-content {
    flex: 1;
    color: var(--text-primary);
}

/* ==========================================
   Publications Section
   ========================================== */
.publications-list {
    display: flex;
    flex-direction: column;
    gap: 32px;
}

.publication-card {
    background-color: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: var(--border-radius-lg);
    overflow: hidden;
    transition: box-shadow var(--transition-fast), transform var(--transition-fast);
}

.publication-card:hover {
    box-shadow: 0 4px 20px var(--shadow);
    transform: translateY(-2px);
}

.publication-media {
    width: 100%;
    max-height: 400px;
    overflow: hidden;
    background-color: var(--bg-tertiary);
}

.publication-media video,
.publication-media img {
    width: 100%;
    height: auto;
    max-height: 400px;
    object-fit: contain;
    display: block;
}

.publication-info {
    padding: 24px;
}

.publication-title {
    font-size: 1.15rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 8px;
    line-height: 1.4;
}

.publication-authors {
    font-size: 0.95rem;
    color: var(--text-secondary);
    margin-bottom: 8px;
}

.publication-authors strong {
    color: var(--text-primary);
    font-weight: 600;
}

.publication-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin-bottom: 16px;
    font-size: 0.9rem;
}

.publication-venue {
    color: var(--accent);
    font-weight: 500;
}

.publication-year {
    color: var(--text-secondary);
}

.publication-type {
    display: inline-block;
    padding: 2px 8px;
    background-color: var(--bg-tertiary);
    border-radius: 4px;
    font-size: 0.8rem;
    color: var(--text-secondary);
}

.publication-links {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
}

.publication-link {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 12px;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--border-radius);
    font-size: 0.85rem;
    color: var(--text-primary);
    transition: all var(--transition-fast);
}

.publication-link:hover {
    background-color: var(--accent);
    border-color: var(--accent);
    color: #ffffff;
}

/* ==========================================
   Education Section
   ========================================== */
.education-list {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.education-item {
    display: flex;
    gap: 20px;
    padding: 24px;
    background-color: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: var(--border-radius-lg);
    transition: box-shadow var(--transition-fast);
}

.education-item:hover {
    box-shadow: 0 4px 20px var(--shadow);
}

.education-logo {
    flex-shrink: 0;
    width: 80px;
    height: 80px;
}

.education-logo img {
    width: 100%;
    height: 100%;
    object-fit: contain;
}

.education-info {
    flex: 1;
}

.education-school {
    font-size: 1.15rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 4px;
}

.education-degree {
    font-size: 0.95rem;
    color: var(--accent);
    margin-bottom: 4px;
}

.education-date {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: 8px;
}

.education-details {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

.education-details ul {
    margin-top: 8px;
    padding-left: 20px;
}

.education-details li {
    list-style-type: disc;
    margin-bottom: 4px;
}

/* ==========================================
   Experience Section
   ========================================== */
.experience-list {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.experience-item {
    display: flex;
    gap: 20px;
    padding: 24px;
    background-color: var(--card-bg);
    border: 1px solid var(--border);
    border-radius: var(--border-radius-lg);
    transition: box-shadow var(--transition-fast);
}

.experience-item:hover {
    box-shadow: 0 4px 20px var(--shadow);
}

.experience-logo {
    flex-shrink: 0;
    width: 80px;
    height: 80px;
}

.experience-logo img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    border-radius: var(--border-radius);
}

.experience-info {
    flex: 1;
}

.experience-company {
    font-size: 1.15rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 4px;
}

.experience-role {
    font-size: 0.95rem;
    color: var(--accent);
    margin-bottom: 4px;
}

.experience-date {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: 8px;
}

.experience-description {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

.experience-description ul {
    margin-top: 8px;
    padding-left: 20px;
}

.experience-description li {
    list-style-type: disc;
    margin-bottom: 6px;
}

/* ==========================================
   Awards Section
   ========================================== */
.awards-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.award-item {
    display: flex;
    gap: 16px;
    padding: 16px;
    background-color: var(--bg-secondary);
    border-radius: var(--border-radius);
    border-left: 3px solid var(--accent);
}

.award-date {
    flex-shrink: 0;
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--accent);
    min-width: 80px;
}

.award-content {
    flex: 1;
    color: var(--text-primary);
    font-size: 0.95rem;
}

/* ==========================================
   CV Section
   ========================================== */
.cv-content {
    text-align: center;
}

.cv-preview {
    width: 100%;
    height: 600px;
    margin-bottom: 24px;
    border: 1px solid var(--border);
    border-radius: var(--border-radius-lg);
    overflow: hidden;
    background-color: var(--bg-secondary);
}

.cv-preview iframe {
    width: 100%;
    height: 100%;
    border: none;
}

.cv-download {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 24px;
    background-color: var(--accent);
    color: #ffffff;
    border-radius: var(--border-radius);
    font-size: 1rem;
    font-weight: 500;
    transition: background-color var(--transition-fast);
}

.cv-download:hover {
    background-color: var(--accent-hover);
    color: #ffffff;
}

/* ==========================================
   Footer
   ========================================== */
.footer {
    padding: 32px 0;
    background-color: var(--bg-secondary);
    border-top: 1px solid var(--border);
    text-align: center;
}

.footer-copyright {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: 8px;
}

.footer-last-modified {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-top: 8px;
    opacity: 0.8;
}

.footer-wakatime {
    margin-bottom: 20px;
}

.footer-wakatime embed {
    max-width: 100%;
    border-radius: var(--border-radius);
}

.footer-clustermaps {
    margin-bottom: 20px;
}

.footer-stats {
    font-size: 0.85rem;
    color: var(--text-secondary);
}

/* ==========================================
   Utilities
   ========================================== */
.hidden {
    display: none !important;
}

/* ==========================================
   Responsive Design
   ========================================== */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: var(--nav-height);
        left: 0;
        right: 0;
        background-color: var(--bg-primary);
        flex-direction: column;
        padding: 24px;
        gap: 16px;
        border-bottom: 1px solid var(--border);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: all var(--transition-normal);
    }

    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .nav-hamburger {
        display: flex;
    }

    .nav-hamburger.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }

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

    .nav-hamburger.active span:nth-child(3) {
        transform: rotate(-45deg) translate(5px, -5px);
    }

    .home-content {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }

    .home-avatar-container {
        width: 100%;
    }

    .wakatime-chart {
        width: 100%;
        max-width: 250px;
    }

    .home-avatar img {
        width: 150px;
        height: 150px;
    }

    .home-name {
        font-size: 2rem;
    }

    .home-social {
        justify-content: center;
    }

    .section {
        padding: 60px 0;
    }

    .section-title {
        font-size: 1.5rem;
    }

    .publication-info,
    .project-info {
        padding: 16px;
    }

    .cv-preview {
        height: 400px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }

    .home-name {
        font-size: 1.75rem;
    }

    .home-avatar img {
        width: 120px;
        height: 120px;
    }

    .social-link {
        padding: 8px 12px;
        font-size: 0.85rem;
    }

    .news-item {
        flex-direction: column;
        gap: 8px;
    }

    .news-date {
        min-width: auto;
    }
}