/* 
 * Portfolio Website Styles
 * A clean, minimalist design inspired by simple portfolio templates
 */

/* ============================
   CSS Custom Properties
   ============================ */
:root {
    /* Colors */
    --color-bg: #ffffff;
    --color-text: #1a1a1a;
    --color-text-muted: #666666;
    --color-text-light: #999999;
    --color-border: #e5e5e5;
    --color-accent: #1a1a1a;
    --color-accent-hover: #333333;
    
    /* Typography */
    --font-sans: 'DM Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --font-serif: 'Instrument Serif', Georgia, 'Times New Roman', serif;
    
    /* Spacing */
    --section-padding: 120px;
    --container-width: 1100px;
    
    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-normal: 0.3s ease;
}

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

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

body {
    font-family: var(--font-sans);
    font-size: 1rem;
    line-height: 1.7;
    color: var(--color-text);
    background-color: var(--color-bg);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

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

ul {
    list-style: none;
}

/* ============================
   Container
   ============================ */
.container {
    width: 100%;
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 24px;
}

/* ============================
   Typography
   ============================ */
h1, h2, h3, h4 {
    font-weight: 400;
    line-height: 1.2;
}

h1 {
    font-family: var(--font-serif);
    font-size: clamp(2.5rem, 6vw, 4.5rem);
    letter-spacing: -0.02em;
}

h2.section-title {
    font-family: var(--font-serif);
    font-size: clamp(1.75rem, 4vw, 2.5rem);
    margin-bottom: 48px;
    position: relative;
}

h2.section-title + .section-subtitle {
    margin-top: -32px;
}

.section-subtitle {
    font-size: 1rem;
    color: var(--color-text-muted);
    font-style: italic;
    margin-bottom: 48px;
}

h3 {
    font-size: 1.125rem;
    font-weight: 500;
}

/* ============================
   Buttons
   ============================ */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 10px 24px;
    font-size: 0.875rem;
    font-weight: 500;
    border-radius: 4px;
    transition: all var(--transition-fast);
    cursor: pointer;
}

.btn-outline {
    border: 1px solid var(--color-border);
    background: transparent;
}

.btn-outline:hover {
    border-color: var(--color-text);
    background: var(--color-text);
    color: var(--color-bg);
}

.btn-primary {
    background: var(--color-accent);
    color: var(--color-bg);
    border: 1px solid var(--color-accent);
}

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

.btn-linkedin {
    background: #0A66C2;
    color: #ffffff;
    border: 1px solid #0A66C2;
}

.btn-linkedin:hover {
    background: #004182;
    border-color: #004182;
}

.btn-large {
    padding: 16px 40px;
    font-size: 1rem;
}

/* ============================
   Header
   ============================ */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 100;
    background: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
}

.header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 72px;
}

.logo {
    font-family: monospace;
    font-size: 1.25rem;
    font-weight: 600;
}

.nav {
    display: flex;
    align-items: center;
    gap: 48px;
}

.nav-list {
    display: flex;
    gap: 32px;
}

.nav-list a {
    font-size: 0.875rem;
    color: var(--color-text-muted);
    transition: color var(--transition-fast);
}

.nav-list a:hover {
    color: var(--color-text);
}

.nav-buttons {
    display: flex;
    gap: 12px;
}

/* Hamburger Menu */
.hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
}

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

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

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

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

/* Mobile Navigation */
.mobile-nav {
    display: none;
    position: fixed;
    top: 72px;
    left: 0;
    right: 0;
    bottom: 0;
    background: var(--color-bg);
    z-index: 99;
    padding: 32px 24px;
    opacity: 0;
    visibility: hidden;
    transition: all var(--transition-normal);
}

.mobile-nav.active {
    opacity: 1;
    visibility: visible;
}

.mobile-nav-list {
    display: flex;
    flex-direction: column;
    gap: 24px;
}

.mobile-nav-list a {
    font-size: 1.5rem;
    font-family: var(--font-serif);
}

.mobile-nav-list .highlight {
    color: var(--color-accent);
}

.mobile-nav-list .highlight-linkedin {
    color: #0A66C2;
}

/* ============================
   Hero Section
   ============================ */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: 72px;
}

.hero-content {
    width: 100%;
}

.hero-text {
    max-width: 700px;
}

.hero-text h1 {
    margin-bottom: 16px;
}

.tagline {
    font-size: 1.25rem;
    color: var(--color-text-muted);
    margin-bottom: 48px;
}

.scroll-indicator {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: -8px;
    color: var(--color-text-light);
    animation: bounce 2s ease infinite;
}

.scroll-indicator svg {
    margin-top: -12px;
}

.scroll-indicator svg:first-child {
    margin-top: 0;
}

@keyframes bounce {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(8px); }
}

/* ============================
   About Section
   ============================ */
.about {
    padding: var(--section-padding) 0;
    border-top: 1px solid var(--color-border);
}

.about-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 64px;
    align-items: center;
}

.about-text p {
    margin-bottom: 24px;
    color: var(--color-text-muted);
}

.about-text p:last-child {
    margin-bottom: 0;
}

.about-text strong {
    color: var(--color-text);
    font-weight: 500;
}

.about-image {
    position: relative;
}

.about-image img {
    width: 100%;
    max-width: 400px;
    margin: 0 auto;
    border-radius: 8px;
    filter: grayscale(20%);
    transition: filter var(--transition-normal);
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.12);
}

.about-image:hover img {
    filter: grayscale(0%);
}

/* ============================
   Experience Section
   ============================ */
.experience {
    padding: var(--section-padding) 0;
    background: #fafafa;
}

.experience-list {
    display: flex;
    flex-direction: column;
    gap: 0;
}

.experience-item {
    display: grid;
    grid-template-columns: 280px 1px 1fr;
    gap: 40px;
    padding: 40px 0;
    border-bottom: 1px solid var(--color-border);
}

.experience-item:first-child {
    padding-top: 0;
}

.experience-item:last-child {
    border-bottom: none;
    padding-bottom: 0;
}

.experience-left {
    display: flex;
    flex-direction: column;
}

.job-title {
    font-size: 1.25rem;
    font-weight: 500;
    margin-bottom: 4px;
}

.company {
    font-size: 1rem;
    color: var(--color-text-muted);
    margin-bottom: 12px;
}

.period {
    display: inline-block;
    font-size: 0.75rem;
    color: var(--color-text-light);
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

.experience-divider {
    width: 1px;
    background: var(--color-border);
    align-self: stretch;
}

.experience-right {
    display: flex;
    flex-direction: column;
    justify-content: center;
    gap: 20px;
}

.experience-right p {
    font-size: 0.875rem;
    color: var(--color-text-muted);
    line-height: 1.7;
    margin-top: 6px;
}

.role {
    padding-bottom: 16px;
    border-bottom: 1px solid var(--color-border);
}

.role:last-child {
    padding-bottom: 0;
    border-bottom: none;
}

.role-title {
    display: block;
    font-size: 1rem;
    font-weight: 500;
    color: var(--color-text);
    margin-bottom: 2px;
}

.role-period {
    display: block;
    font-size: 0.75rem;
    color: var(--color-text-light);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* ============================
   Projects Section
   ============================ */
.projects {
    padding: var(--section-padding) 0;
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 48px;
}

.project-card {
    background: #fafafa;
    border-radius: 8px;
    overflow: hidden;
    transition: transform var(--transition-normal), box-shadow var(--transition-normal);
}

.project-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.08);
}

.project-images {
    display: flex;
    gap: 8px;
    padding: 24px;
    background: #f0f0f0;
    justify-content: center;
}

.project-images img {
    max-height: 280px;
    width: auto;
    border-radius: 4px;
    box-shadow: 0 4px 16px rgba(0, 0, 0, 0.1);
}

.project-info {
    padding: 24px;
}

.project-info h3 {
    margin-bottom: 8px;
}

.project-info p {
    font-size: 0.875rem;
    color: var(--color-text-muted);
    margin-bottom: 16px;
}

.project-tags {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

.project-tags span {
    font-size: 0.75rem;
    padding: 4px 12px;
    background: var(--color-text);
    color: var(--color-bg);
    border-radius: 100px;
}

/* ============================
   Skills Section
   ============================ */
.skills {
    padding: var(--section-padding) 0;
    background: #fafafa;
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(120px, 1fr));
    gap: 32px;
}

.skill-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
    padding: 24px;
    background: var(--color-bg);
    border-radius: 8px;
    transition: transform var(--transition-fast);
}

.skill-item:hover {
    transform: translateY(-4px);
}

.skill-item img {
    width: 48px;
    height: 48px;
    object-fit: contain;
}

.skill-item span {
    font-size: 0.875rem;
    font-weight: 500;
    text-align: center;
}

/* ============================
   Publications Section
   ============================ */
.publications {
    padding: var(--section-padding) 0;
    background: #fafafa;
}

.publications-list {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 32px;
}

.publication-item {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    gap: 16px;
    padding: 32px;
    background: var(--color-bg);
    border-radius: 8px;
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
}

.publication-item:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 32px rgba(0, 0, 0, 0.08);
}

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

.publication-content h3 {
    font-size: 1.125rem;
    font-weight: 500;
    margin-bottom: 4px;
}

.publication-title {
    font-size: 0.875rem;
    color: var(--color-text-muted);
    margin-bottom: 8px;
}

.publication-year {
    font-size: 0.75rem;
    color: var(--color-text-light);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    display: block;
    margin-bottom: 16px;
}

.publication-link {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--color-text);
    transition: gap var(--transition-fast);
}

.publication-link:hover {
    gap: 10px;
}

.publication-link svg {
    transition: transform var(--transition-fast);
}

.publication-link:hover svg {
    transform: translate(2px, -2px);
}

/* ============================
   Education Section
   ============================ */
.education {
    padding: var(--section-padding) 0;
}

.education-list {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 48px;
}

.education-item {
    display: flex;
    gap: 24px;
    align-items: flex-start;
}

.education-icon {
    flex-shrink: 0;
    color: var(--color-text);
    opacity: 0.8;
}

.education-content h3 {
    font-size: 1.125rem;
    font-weight: 500;
    margin-bottom: 4px;
}

.institution {
    display: block;
    color: var(--color-text-muted);
    margin-bottom: 8px;
}

/* ============================
   Contact Section
   ============================ */
.contact {
    padding: var(--section-padding) 0;
    background: #fafafa;
    text-align: center;
}

.contact-intro {
    font-size: 1.125rem;
    color: var(--color-text-muted);
    max-width: 500px;
    margin: 0 auto 48px;
}

.contact-methods {
    display: flex;
    justify-content: center;
    gap: 48px;
    margin-bottom: 48px;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 12px;
    color: var(--color-text-muted);
    transition: color var(--transition-fast);
}

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

.contact-item img {
    width: 24px;
    height: 24px;
    opacity: 0.7;
}

/* ============================
   Footer
   ============================ */
.footer {
    padding: 48px 0;
    border-top: 1px solid var(--color-border);
}

.footer .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.footer p {
    font-size: 0.875rem;
    color: var(--color-text-muted);
}

.social-links {
    display: flex;
    gap: 24px;
}

.social-links a {
    color: var(--color-text-muted);
    transition: color var(--transition-fast);
}

.social-links a:hover {
    color: var(--color-text);
}

.social-links svg {
    width: 20px;
    height: 20px;
}

/* ============================
   Responsive Design
   ============================ */
@media (max-width: 1024px) {
    :root {
        --section-padding: 80px;
    }
    
    .about-content {
        gap: 48px;
    }
    
    .projects-grid {
        gap: 32px;
    }
    
    .experience-item {
        grid-template-columns: 220px 1px 1fr;
        gap: 24px;
    }
    
    .publications-list {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 768px) {
    :root {
        --section-padding: 64px;
    }
    
    /* Navigation */
    .nav {
        display: none;
    }
    
    .hamburger {
        display: flex;
    }
    
    .mobile-nav {
        display: block;
    }
    
    /* Hero */
    .hero {
        min-height: 80vh;
    }
    
    .tagline {
        font-size: 1.1rem;
    }
    
    /* About */
    .about-content {
        grid-template-columns: 1fr;
        gap: 32px;
    }
    
    .about-image {
        order: -1;
    }
    
    .about-image img {
        max-width: 280px;
    }
    
    /* Experience */
    .experience-item {
        grid-template-columns: 1fr;
        gap: 16px;
    }
    
    .experience-divider {
        width: 100%;
        height: 1px;
    }
    
    /* Publications */
    .publications-list {
        grid-template-columns: 1fr;
    }
    
    /* Projects */
    .projects-grid {
        grid-template-columns: 1fr;
    }
    
    .project-images img {
        max-height: 200px;
    }
    
    /* Education */
    .education-list {
        grid-template-columns: 1fr;
        gap: 32px;
    }
    
    /* Contact */
    .contact-methods {
        flex-direction: column;
        gap: 24px;
    }
    
    /* Footer */
    .footer .container {
        flex-direction: column;
        gap: 24px;
        text-align: center;
    }
}

@media (max-width: 480px) {
    :root {
        --section-padding: 48px;
    }
    
    h2.section-title {
        margin-bottom: 32px;
    }
    
    .skills-grid {
        grid-template-columns: repeat(2, 1fr);
        gap: 16px;
    }
    
    .skill-item {
        padding: 16px;
    }
    
    .skill-item img {
        width: 40px;
        height: 40px;
    }
    
    .project-images {
        flex-direction: column;
        align-items: center;
    }
    
    .project-images img {
        max-height: 300px;
    }
}

/* ============================
   Animations
   ============================ */
@media (prefers-reduced-motion: no-preference) {
    .about-image img,
    .project-card,
    .skill-item,
    .experience-item {
        animation: fadeInUp 0.6s ease both;
    }
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}