/* ===========================
   CSS Variables - Dark & Light Mode
   =========================== */

:root[data-theme="dark"] {
    /* Dark Theme Colors */
    --color-bg-primary: #0a0a0a;
    --color-bg-secondary: #111111;
    --color-bg-tertiary: #1a1a1a;
    --color-bg-sidebar: #0d0d0d;
    
    --color-text-primary: #e5e5e5;
    --color-text-secondary: #a0a0a0;
    --color-text-tertiary: #6b6b6b;
    --color-text-comment: #5c5c5c;
    
    --color-accent: #10b981;
    --color-accent-hover: #059669;
    
    --color-border: #1f1f1f;
    --color-border-light: #2a2a2a;
}

:root[data-theme="light"] {
    /* Light Theme Colors */
    --color-bg-primary: #ffffff;
    --color-bg-secondary: #f8f9fa;
    --color-bg-tertiary: #e9ecef;
    --color-bg-sidebar: #f5f7fa;
    
    --color-text-primary: #1a1a1a;
    --color-text-secondary: #4a4a4a;
    --color-text-tertiary: #7a7a7a;
    --color-text-comment: #9a9a9a;
    
    --color-accent: #10b981;
    --color-accent-hover: #059669;
    
    --color-border: #e0e0e0;
    --color-border-light: #d0d0d0;
}

:root {
    /* Typography - Monospace */
    --font-mono: 'JetBrains Mono', 'Consolas', 'Monaco', monospace;
    
    /* Spacing */
    --space-xs: 0.5rem;
    --space-sm: 0.75rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    
    /* Sidebar Widths */
    --sidebar-left-width: 280px;
    --sidebar-right-width: 200px;
    
    /* Transitions */
    --transition: 0.2s ease;
    --theme-transition: 0.3s ease;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-mono);
    font-size: 13px;
    background-color: var(--color-bg-primary);
    color: var(--color-text-primary);
    line-height: 1.6;
    overflow-x: hidden;
    transition: background-color var(--theme-transition), color var(--theme-transition);
}

/* ===========================
   Theme Toggle Button
   =========================== */

.theme-toggle {
    position: fixed;
    top: var(--space-md);
    right: var(--space-md);
    z-index: 1000;
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all var(--transition);
}

.theme-toggle:hover {
    background: var(--color-bg-tertiary);
    border-color: var(--color-accent);
    transform: rotate(15deg);
}

.sun-icon,
.moon-icon {
    position: absolute;
    color: var(--color-accent);
    transition: opacity var(--transition), transform var(--transition);
}

:root[data-theme="dark"] .sun-icon {
    opacity: 1;
    transform: rotate(0deg);
}

:root[data-theme="dark"] .moon-icon {
    opacity: 0;
    transform: rotate(180deg);
}

:root[data-theme="light"] .sun-icon {
    opacity: 0;
    transform: rotate(-180deg);
}

:root[data-theme="light"] .moon-icon {
    opacity: 1;
    transform: rotate(0deg);
}

/* ===========================
   Main Container - 3 Column Layout
   =========================== */

.container {
    display: grid;
    grid-template-columns: var(--sidebar-left-width) 1fr var(--sidebar-right-width);
    min-height: 100vh;
}

/* ===========================
   Left Sidebar
   =========================== */

.left-sidebar {
    background: var(--color-bg-sidebar);
    border-right: 1px solid var(--color-border);
    padding: var(--space-lg);
    position: sticky;
    top: 0;
    height: 100vh;
    overflow-y: auto;
    display: flex;
    flex-direction: column;
    transition: background-color var(--theme-transition), border-color var(--theme-transition);
}

.sidebar-header {
    margin-bottom: var(--space-xl);
    padding-bottom: var(--space-md);
    border-bottom: 1px solid var(--color-border);
}

.code-comment {
    color: var(--color-text-comment);
    font-size: 12px;
    font-style: italic;
}

/* Profile Section */
.profile-section {
    text-align: center;
    margin-bottom: var(--space-xl);
}

.profile-image {
    width: 80px;
    height: 80px;
    border-radius: 50%;
    object-fit: cover;
    margin-bottom: var(--space-md);
    border: 2px solid var(--color-border-light);
    transition: border-color var(--theme-transition);
}

.profile-name {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: var(--space-xs);
    color: var(--color-text-primary);
}

.profile-title {
    font-size: 13px;
    color: var(--color-text-secondary);
    font-weight: 400;
}

/* Bio Section */
.bio-section {
    margin-bottom: var(--space-xl);
    padding-bottom: var(--space-xl);
    border-bottom: 1px solid var(--color-border);
}

.bio-section p {
    font-size: 12px;
    line-height: 1.7;
    color: var(--color-text-secondary);
}

/* Contact Section */
.contact-section {
    margin-bottom: var(--space-lg);
    padding-bottom: var(--space-lg);
    border-bottom: 1px solid var(--color-border);
}

.contact-item {
    display: flex;
    align-items: flex-start;
    gap: var(--space-sm);
    margin-bottom: var(--space-sm);
    font-size: 11px;
    color: var(--color-text-secondary);
    text-decoration: none;
    transition: color var(--transition);
}

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

.contact-item svg {
    flex-shrink: 0;
    margin-top: 2px;
}

/* Social Section */
.social-section {
    margin-bottom: var(--space-xl);
    padding-bottom: var(--space-xl);
    border-bottom: 1px solid var(--color-border);
}

.social-link {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-sm);
    background: var(--color-bg-tertiary);
    border: 1px solid var(--color-border);
    border-radius: 4px;
    color: var(--color-text-secondary);
    text-decoration: none;
    font-size: 12px;
    transition: all var(--transition);
}

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

/* Action Buttons */
.action-buttons {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
    margin-top: auto;
}

.btn {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-sm);
    padding: var(--space-sm) var(--space-md);
    border-radius: 4px;
    text-decoration: none;
    font-size: 12px;
    font-weight: 500;
    transition: all var(--transition);
    border: 1px solid var(--color-border-light);
}

.btn-primary {
    background: var(--color-accent);
    color: #ffffff;
    border-color: var(--color-accent);
}

.btn-primary:hover {
    background: var(--color-accent-hover);
    border-color: var(--color-accent-hover);
}

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

.btn-secondary:hover {
    background: var(--color-bg-tertiary);
    border-color: var(--color-border-light);
}

/* ===========================
   Main Content Area
   =========================== */

.main-content {
    background: var(--color-bg-primary);
    padding: var(--space-xl);
    overflow-y: auto;
    max-width: 900px;
    transition: background-color var(--theme-transition);
}

.content-section {
    margin-bottom: var(--space-2xl);
    animation: fadeIn 0.5s ease;
}

.section-comment {
    color: var(--color-text-comment);
    font-size: 12px;
    margin-bottom: var(--space-md);
}

.section-comment::before {
    content: '<!-- ';
}

.section-comment::after {
    content: ' -->';
}

.section-title {
    font-size: 28px;
    font-weight: 700;
    margin-bottom: var(--space-xl);
    color: var(--color-text-primary);
}

/* Hero Section */
.hero-title {
    font-size: 48px;
    font-weight: 700;
    margin-bottom: var(--space-lg);
    color: var(--color-text-primary);
    letter-spacing: -0.5px;
}

.hero-description {
    font-size: 14px;
    line-height: 1.8;
    color: var(--color-text-secondary);
    margin-bottom: var(--space-xl);
    max-width: 700px;
}

/* About Section */
.about-text {
    font-size: 14px;
    line-height: 1.8;
    color: var(--color-text-secondary);
    margin-bottom: var(--space-lg);
}

/* Timeline */
.timeline {
    display: flex;
    flex-direction: column;
    gap: var(--space-xl);
}

.timeline-item {
    position: relative;
    padding-left: var(--space-lg);
    border-left: 1px solid var(--color-border);
    transition: border-color var(--theme-transition);
}

.timeline-item::before {
    content: '';
    position: absolute;
    left: -5px;
    top: 4px;
    width: 8px;
    height: 8px;
    background: var(--color-accent);
    border-radius: 50%;
}

.timeline-period {
    font-size: 11px;
    color: var(--color-accent);
    margin-bottom: var(--space-xs);
    font-weight: 500;
}

.timeline-title {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: var(--space-xs);
    color: var(--color-text-primary);
}

.timeline-company {
    font-size: 13px;
    color: var(--color-text-tertiary);
    margin-bottom: var(--space-sm);
}

.timeline-description {
    font-size: 13px;
    line-height: 1.7;
    color: var(--color-text-secondary);
    padding-left: var(--space-md);
}

.timeline-description li {
    margin-bottom: var(--space-xs);
}

/* Awards List */
.awards-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-lg);
}

.award-item {
    display: grid;
    grid-template-columns: 60px 1fr;
    gap: var(--space-lg);
    padding: var(--space-lg);
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: 6px;
    transition: all var(--transition);
}

.award-item.highlight {
    border-color: var(--color-accent);
    background: var(--color-bg-tertiary);
}

.award-item:hover {
    border-color: var(--color-accent);
}

.award-year {
    font-size: 11px;
    color: var(--color-accent);
    font-weight: 600;
}

.award-content h3 {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: var(--space-xs);
    color: var(--color-text-primary);
}

.award-subtitle {
    font-size: 12px;
    color: var(--color-accent);
    margin-bottom: var(--space-sm);
    font-style: italic;
}

.award-description {
    font-size: 13px;
    line-height: 1.7;
    color: var(--color-text-secondary);
}

/* Publications List */
.publications-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-lg);
}

.publication-item {
    padding: var(--space-lg);
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: 6px;
    transition: all var(--transition);
}

.publication-item:hover {
    border-color: var(--color-accent);
}

.publication-item h3 {
    font-size: 15px;
    font-weight: 600;
    margin-bottom: var(--space-xs);
    color: var(--color-text-primary);
}

.publication-venue {
    font-size: 12px;
    color: var(--color-text-tertiary);
    margin-bottom: var(--space-xs);
}

.publication-description {
    font-size: 13px;
    line-height: 1.7;
    color: var(--color-text-secondary);
    margin-bottom: var(--space-sm);
}

.publication-status {
    display: inline-block;
    padding: 3px 10px;
    background: var(--color-bg-tertiary);
    border: 1px solid var(--color-border);
    border-radius: 3px;
    font-size: 10px;
    color: var(--color-accent);
    font-weight: 500;
}

/* Skills Section */
.skills-division {
    margin-bottom: var(--space-xl);
}

.skills-division:last-child {
    margin-bottom: 0;
}

.skills-division-title {
    font-size: 14px;
    font-weight: 600;
    color: var(--color-text-primary);
    margin-bottom: var(--space-md);
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
    gap: var(--space-md);
}

.skill-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    padding: var(--space-lg);
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: 6px;
    transition: all var(--transition);
}

.skill-item:hover {
    border-color: var(--color-accent);
}

.skill-name {
    font-size: 12px;
    font-weight: 500;
    color: var(--color-text-primary);
    text-align: center;
    line-height: 1.3;
}

/* Books List */
.books-list {
    display: flex;
    flex-direction: column;
    gap: var(--space-lg);
}

.book-item {
    display: grid;
    grid-template-columns: 60px 1fr;
    gap: var(--space-lg);
    padding: var(--space-lg);
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: 6px;
    transition: all var(--transition);
}

.book-item:hover {
    border-color: var(--color-accent);
}

.book-cover {
    width: 60px;
    height: 90px;
    border-radius: 4px;
    overflow: hidden;
    flex-shrink: 0;
    background: var(--color-bg-tertiary);
}

.book-cover img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    display: block;
}

.book-info h3 {
    font-size: 14px;
    font-weight: 600;
    margin-bottom: var(--space-xs);
    color: var(--color-text-primary);
}

.book-status {
    font-size: 11px;
    color: var(--color-accent);
    margin-bottom: var(--space-sm);
    font-weight: 500;
}

.book-note {
    font-size: 12px;
    line-height: 1.6;
    color: var(--color-text-secondary);
    font-style: italic;
}

/* Contact Section */
.contact-intro {
    font-size: 14px;
    line-height: 1.8;
    color: var(--color-text-secondary);
    margin-bottom: var(--space-xl);
}

.contact-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--space-lg);
}

.contact-card {
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: 6px;
    padding: var(--space-lg);
    text-align: center;
    transition: all var(--transition);
}

.contact-card:hover {
    border-color: var(--color-accent);
}

.contact-card svg {
    color: var(--color-accent);
    margin-bottom: var(--space-md);
}

.contact-card h3 {
    font-size: 13px;
    font-weight: 600;
    margin-bottom: var(--space-sm);
    color: var(--color-text-primary);
}

.contact-card a {
    font-size: 12px;
    color: var(--color-text-secondary);
    text-decoration: none;
    transition: color var(--transition);
}

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

/* ===========================
   Right Sidebar - Index
   =========================== */

.right-sidebar {
    background: var(--color-bg-sidebar);
    border-left: 1px solid var(--color-border);
    padding: var(--space-xl) var(--space-lg);
    position: sticky;
    top: 0;
    height: 100vh;
    overflow-y: auto;
    transition: background-color var(--theme-transition), border-color var(--theme-transition);
}

.index-title {
    font-size: 16px;
    font-weight: 600;
    margin-bottom: var(--space-lg);
    color: var(--color-text-primary);
}

.index-nav {
    display: flex;
    flex-direction: column;
    gap: 2px;
}

.index-link {
    padding: var(--space-sm) var(--space-md);
    color: var(--color-text-secondary);
    text-decoration: none;
    font-size: 13px;
    border-radius: 4px;
    transition: all var(--transition);
    position: relative;
}

.index-link:hover {
    color: var(--color-accent);
    background: var(--color-bg-tertiary);
}

.index-link.active {
    color: var(--color-accent);
    background: var(--color-bg-tertiary);
}

.index-link.active::before {
    content: '';
    position: absolute;
    left: 0;
    top: 50%;
    transform: translateY(-50%);
    width: 2px;
    height: 70%;
    background: var(--color-accent);
}

/* ===========================
   Mobile Menu
   =========================== */

.mobile-menu-toggle {
    display: none;
    position: fixed;
    top: var(--space-md);
    left: var(--space-md);
    z-index: 1000;
    background: var(--color-bg-secondary);
    border: 1px solid var(--color-border);
    border-radius: 4px;
    padding: 8px;
    cursor: pointer;
    flex-direction: column;
    gap: 4px;
}

.mobile-menu-toggle span {
    width: 20px;
    height: 2px;
    background: var(--color-text-primary);
    transition: all var(--transition);
}

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

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

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

/* ===========================
   Animations
   =========================== */

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* ===========================
   Scrollbar Styling
   =========================== */

::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--color-bg-primary);
}

::-webkit-scrollbar-thumb {
    background: var(--color-border-light);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--color-text-tertiary);
}

/* ===========================
   Responsive Design
   =========================== */

/* Tablet */
@media (max-width: 1024px) {
    :root {
        --sidebar-left-width: 260px;
        --sidebar-right-width: 180px;
    }
    
    .main-content {
        padding: var(--space-lg);
    }
    
    .hero-title {
        font-size: 36px;
    }
}

/* Mobile */
@media (max-width: 768px) {
    .container {
        grid-template-columns: 1fr;
    }
    
    .left-sidebar,
    .right-sidebar {
        display: none;
    }
    
    .left-sidebar.active {
        display: flex;
        position: fixed;
        top: 0;
        left: 0;
        width: 280px;
        height: 100vh;
        z-index: 999;
        box-shadow: 4px 0 12px rgba(0,0,0,0.3);
    }
    
    .mobile-menu-toggle {
        display: flex;
    }
    
    .theme-toggle {
        top: var(--space-md);
        right: 60px;
    }
    
    .main-content {
        padding: var(--space-xl) var(--space-md);
        max-width: 100%;
    }
    
    .hero-title {
        font-size: 32px;
    }
    
    .contact-grid {
        grid-template-columns: 1fr;
    }
    
    .timeline-item {
        padding-left: var(--space-md);
    }
}

/* Small Mobile */
@media (max-width: 480px) {
    .hero-title {
        font-size: 28px;
    }
    
    .section-title {
        font-size: 24px;
    }
    
    body {
        font-size: 12px;
    }
    
    .profile-image {
        width: 70px;
        height: 70px;
    }
}

/* Tablet Landscape */
@media (min-width: 768px) and (max-width: 1024px) and (orientation: landscape) {
    .container {
        grid-template-columns: 240px 1fr 160px;
    }
    
    .profile-section {
        margin-bottom: var(--space-lg);
    }
    
    .profile-image {
        width: 70px;
        height: 70px;
    }
}