/* ============================================
   CSS Variables - TEMPLATE: Customize colors here
   ============================================ */
:root {
    /* Primary Colors */
    --primary-color: #2563eb;
    --primary-dark: #1e40af;
    --primary-light: #3b82f6;
    
    /* Neutral Colors */
    --bg-color: #ffffff;
    --bg-alt: #f8fafc;
    --text-color: #1e293b;
    --text-light: #64748b;
    --border-color: #e2e8f0;
    
    /* Accent Colors */
    --accent-color: #10b981;
    --accent-dark: #059669;
    
    /* Typography */
    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-heading: 'Crimson Text', Georgia, serif;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 3rem;
    --spacing-xl: 4rem;
    
    /* Layout */
    --container-width: 1200px;
    --nav-height: 70px;
    --header-height: 60px;
    --sidebar-width: 320px;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    
    /* Transitions */
    --transition: all 0.3s ease;
}

/* Dark mode support (optional) */
@media (prefers-color-scheme: dark) {
    :root {
        --bg-color: #0f172a;
        --bg-alt: #1e293b;
        --text-color: #f1f5f9;
        --text-light: #94a3b8;
        --border-color: #334155;
    }
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-primary);
    font-size: 16px;
    line-height: 1.6;
    color: var(--text-color);
    background-color: var(--bg-color);
    overflow-x: hidden;
}

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

h1 {
    font-size: 3rem;
}

h2 {
    font-size: 2.5rem;
}

h3 {
    font-size: 1.75rem;
}

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

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

a:hover {
    color: var(--primary-dark);
}

/* ============================================
   Header Bar
   ============================================ */
.header-bar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    background-color: var(--bg-color);
    border-bottom: 1px solid var(--border-color);
    z-index: 200;
    box-shadow: var(--shadow-sm);
}

.header-content {
    max-width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: flex-end;
    padding: 0 var(--spacing-md);
    margin-left: var(--sidebar-width);
}

.top-nav {
    display: flex;
    gap: var(--spacing-sm);
    align-items: center;
}

.nav-button {
    padding: 0.5rem 1.25rem;
    background-color: transparent;
    color: var(--text-color);
    border: none;
    border-radius: 6px;
    font-size: 0.9rem;
    font-weight: 500;
    text-decoration: none;
    transition: var(--transition);
    cursor: pointer;
}

.nav-button:hover {
    background-color: var(--bg-alt);
    color: var(--primary-color);
}

/* ============================================
   Sidebar
   ============================================ */
.sidebar {
    position: fixed;
    top: var(--header-height);
    left: 0;
    width: var(--sidebar-width);
    height: calc(100vh - var(--header-height));
    background-color: var(--bg-alt);
    border-right: 1px solid var(--border-color);
    overflow-y: auto;
    z-index: 100;
    padding: var(--spacing-lg) var(--spacing-md);
    display: flex;
    align-items: flex-start;
    justify-content: center;
}

/* Custom scrollbar for sidebar */
.sidebar::-webkit-scrollbar {
    width: 6px;
}

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

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

.sidebar::-webkit-scrollbar-thumb:hover {
    background-color: var(--text-light);
}

.sidebar-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    width: 100%;
    max-width: 280px;
}

.hero-image {
    margin-bottom: var(--spacing-md);
}

.hero-image img {
    width: 180px;
    height: 180px;
    border-radius: 50%;
    object-fit: cover;
    border: 4px solid var(--primary-color);
    box-shadow: var(--shadow-lg);
}

.hero-name {
    font-size: 2rem;
    margin-bottom: var(--spacing-xs);
    color: var(--text-color);
    line-height: 1.2;
}

.hero-title {
    font-size: 1.125rem;
    color: var(--text-light);
    margin-bottom: var(--spacing-sm);
    font-weight: 500;
}

.hero-description {
    font-size: 0.95rem;
    color: var(--text-light);
    margin-bottom: var(--spacing-md);
    line-height: 1.6;
}

.hero-social {
    display: flex;
    justify-content: center;
    gap: var(--spacing-sm);
    margin-top: var(--spacing-sm);
    flex-wrap: wrap;
}

.social-icon {
    width: 20px;
    height: 20px;
    color: var(--text-light);
    transition: var(--transition);
}

.social-icon:hover {
    color: var(--primary-color);
    transform: translateY(-2px);
}

/* ============================================
   Main Content
   ============================================ */
.main-content {
    margin-left: var(--sidebar-width);
    padding-top: var(--header-height);
    min-height: 100vh;
}

/* ============================================
   Container & Sections
   ============================================ */
.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

section {
    padding: var(--spacing-xl) 0;
}

.section-title {
    text-align: center;
    margin-bottom: var(--spacing-lg);
}

.section-subtitle {
    text-align: center;
    color: var(--text-light);
    margin-bottom: var(--spacing-lg);
}

/* ============================================
   About Section
   ============================================ */
.about {
    background-color: var(--bg-alt);
}

.about-content {
    margin-top: var(--spacing-lg);
    max-width: 800px;
    margin-left: auto;
    margin-right: auto;
}

.about-text {
    font-size: 1.125rem;
    line-height: 1.8;
}

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

.detail-section h3 {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-sm);
    color: var(--primary-color);
}

.detail-item {
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-md);
    border-bottom: 1px solid var(--border-color);
}

.detail-item:last-child {
    border-bottom: none;
}

.detail-item strong {
    color: var(--text-color);
}

.detail-item small {
    color: var(--text-light);
    font-style: italic;
}

.interests-list {
    list-style: none;
    padding-left: 0;
}

.interests-list li {
    padding: var(--spacing-xs) 0;
    padding-left: 1.5rem;
    position: relative;
}

.interests-list li::before {
    content: '▸';
    position: absolute;
    left: 0;
    color: var(--primary-color);
}

.skills {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
}

.skill-tag {
    display: inline-block;
    padding: 0.375rem 0.75rem;
    background-color: var(--primary-color);
    color: white;
    border-radius: 20px;
    font-size: 0.875rem;
    font-weight: 500;
}

/* ============================================
   Portfolio Section
   ============================================ */
.projects-grid {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xl);
    margin-top: var(--spacing-lg);
}

/* Horizontal Project Layout (Image Left, Text Right) */
.project-horizontal {
    display: flex;
    gap: var(--spacing-lg);
    align-items: flex-start;
    padding: var(--spacing-md);
    background-color: var(--bg-color);
    border-radius: 8px;
    border: 1px solid var(--border-color);
    transition: var(--transition);
}

.project-horizontal:hover {
    box-shadow: var(--shadow-md);
}

.project-image-left {
    flex: 0 0 300px;
    max-width: 300px;
    height: 200px;
    overflow: hidden;
    /* border-radius: 6px; */
    /* background-color: var(--bg-alt); */
}

.project-image-left img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition);
}

.project-horizontal:hover .project-image-left img {
    transform: scale(1.05);
}

.project-content-right {
    flex: 1;
    display: flex;
    flex-direction: column;
}

.project-card {
    background-color: var(--bg-color);
    border-radius: 8px;
    overflow: hidden;
    box-shadow: var(--shadow-md);
    transition: var(--transition);
    border: 1px solid var(--border-color);
}

.project-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.project-image {
    width: 100%;
    height: 200px;
    overflow: hidden;
    background-color: var(--bg-alt);
}

.project-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: var(--transition);
}

.project-card:hover .project-image img {
    transform: scale(1.05);
}

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

.project-title {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-sm);
    color: var(--text-color);
}

.project-description {
    color: var(--text-light);
    margin-bottom: var(--spacing-md);
    line-height: 1.6;
}

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
    margin-bottom: var(--spacing-md);
}

.tech-tag {
    display: inline-block;
    padding: 0.25rem 0.5rem;
    background-color: var(--bg-alt);
    color: var(--text-color);
    border-radius: 4px;
    font-size: 0.75rem;
    border: 1px solid var(--border-color);
}

.project-links {
    display: flex;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

.project-links a {
    color: var(--primary-color);
    font-weight: 500;
    font-size: 0.875rem;
    padding: 0.5rem 1rem;
    border: 1px solid var(--primary-color);
    border-radius: 4px;
    transition: var(--transition);
}

.project-links a:hover {
    background-color: var(--primary-color);
    color: white;
}

/* ============================================
   Publications Section
   ============================================ */
.publications {
    background-color: var(--bg-alt);
}

.publications-list {
    margin-top: var(--spacing-lg);
}

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

.pub-category-title {
    font-size: 1.5rem;
    margin-bottom: var(--spacing-xs);
    color: var(--text-color);
    font-weight: 600;
}

.pub-category-note {
    color: var(--text-light);
    font-size: 0.9rem;
    margin-bottom: var(--spacing-md);
}

.publication-item {
    margin-bottom: var(--spacing-sm);
    color: var(--text-color);
    font-size: 0.95rem;
    line-height: 1.6;
}

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

.pub-links {
    display: flex;
    gap: var(--spacing-md);
    flex-wrap: wrap;
}

.pub-links a {
    color: var(--primary-color);
    font-size: 0.875rem;
    padding: 0.25rem 0.75rem;
    border: 1px solid var(--primary-color);
    border-radius: 4px;
    transition: var(--transition);
}

.pub-links a:hover {
    background-color: var(--primary-color);
    color: white;
}

/* ============================================
   Contact Section
   ============================================ */
.contact-content {
    text-align: center;
    max-width: 600px;
    margin: 0 auto;
}

.contact-info {
    margin-top: var(--spacing-md);
    text-align: left;
}

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

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

.footer-note {
    font-size: 0.875rem;
    margin-top: var(--spacing-xs);
}

/* ============================================
   Responsive Design
   ============================================ */
@media (max-width: 768px) {
    :root {
        --spacing-xl: 3rem;
        --spacing-lg: 2rem;
    }
    
    h1 {
        font-size: 2.5rem;
    }
    
    h2 {
        font-size: 2rem;
    }
    
    /* Header Bar adjustments for mobile */
    .header-content {
        margin-left: 0;
        padding: 0 var(--spacing-sm);
    }
    
    .nav-button {
        padding: 0.4rem 1rem;
        font-size: 0.85rem;
    }
    
    /* Sidebar becomes top section on mobile */
    .sidebar {
        position: relative;
        top: 0;
        width: 100%;
        height: auto;
        border-right: none;
        border-bottom: 1px solid var(--border-color);
        padding: var(--spacing-md);
    }
    
    .sidebar-content {
        padding: var(--spacing-sm) 0;
    }
    
    .main-content {
        margin-left: 0;
        padding-top: var(--header-height);
    }
    
    .hero-image img {
        width: 150px;
        height: 150px;
    }
    
    .hero-name {
        font-size: 1.75rem;
    }
    
    .project-horizontal {
        flex-direction: column;
        gap: var(--spacing-md);
    }
    
    .project-image-left {
        flex: 0 0 auto;
        max-width: 100%;
        width: 100%;
    }
}

@media (max-width: 480px) {
    .hero-name {
        font-size: 2rem;
    }
    
    .hero-title {
        font-size: 1.25rem;
    }
    
    .section-title {
        font-size: 2rem;
    }
}

/* ============================================
   Print Styles
   ============================================ */
@media print {
    .navbar,
    .hero-social,
    .project-links,
    .pub-links,
    .footer {
        display: none;
    }
    
    .hero {
        padding-top: var(--spacing-md);
    }
    
    section {
        page-break-inside: avoid;
    }
}