:root {
    /* Colors - Light Theme */
    --bg: #ffffff;
    --bg-secondary: #f8f8f8;
    --text: #000000;
    --text-secondary: #666666;
    --text-tertiary: #999999;
    --border: #e8e8e8;
    --accent: #0066cc;
    
    /* Dark Theme */
    --bg-dark: #0a0a0a;
    --bg-secondary-dark: #1a1a1a;
    --text-dark: #ffffff;
    --text-secondary-dark: #b0b0b0;
    --text-tertiary-dark: #808080;
    --border-dark: #333333;
    --accent-dark: #4fa3ff;
}

[data-theme="dark"] {
    --bg: var(--bg-dark);
    --bg-secondary: var(--bg-secondary-dark);
    --text: var(--text-dark);
    --text-secondary: var(--text-secondary-dark);
    --text-tertiary: var(--text-tertiary-dark);
    --border: var(--border-dark);
    --accent: var(--accent-dark);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "Helvetica Neue", sans-serif;
    background-color: var(--bg);
    color: var(--text);
    line-height: 1.6;
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* Header Navigation */
.header {
    position: sticky;
    top: 0;
    background-color: var(--bg);
    border-bottom: 1px solid var(--border);
    z-index: 1000;
    transition: all 0.3s ease;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: 1.5rem;
}

.nav-logo {
    font-size: 0.85rem;
    font-weight: 700;
    letter-spacing: 0.15em;
    text-decoration: none;
    color: var(--text);
    transition: color 0.3s ease;
}

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

.nav-menu {
    display: flex;
    list-style: none;
    gap: 2rem;
    flex: 1;
    justify-content: center;
}

.nav-menu a {
    font-size: 0.75rem;
    font-weight: 500;
    letter-spacing: 0.1em;
    text-decoration: none;
    color: var(--text-secondary);
    transition: color 0.3s ease;
}

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

.nav-menu a.active {
    color: var(--accent);
    font-weight: 600;
    border-bottom: 2px solid var(--accent);
    padding-bottom: 0.25rem;
}

.theme-toggle {
    background: none;
    border: 1px solid var(--border);
    color: var(--text);
    cursor: pointer;
    font-size: 1rem;
    padding: 0.6rem 0.75rem;
    border-radius: 4px;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    justify-content: center;
    height: 2.5rem;
    min-width: 2.5rem;
    line-height: 1;
}

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

.theme-toggle i {
    display: flex;
    align-items: center;
    justify-content: center;
}

/* Main Content */
main {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* Hero Section */
.hero {
    padding: 6rem 0;
    text-align: center;
}

.hero h1 {
    font-size: 3.5rem;
    font-weight: 700;
    line-height: 1.2;
    margin-bottom: 1.5rem;
    letter-spacing: -0.02em;
}

.tagline {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 3rem;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

.intro {
    max-width: 800px;
    margin: 2rem auto;
    color: var(--text-secondary);
    line-height: 1.8;
}

.intro p {
    margin-bottom: 1.5rem;
    font-size: 1rem;
}

.cta-links {
    margin-top: 2rem;
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1rem;
    flex-wrap: wrap;
}

.cta-link {
    font-size: 0.85rem;
    font-weight: 600;
    letter-spacing: 0.1em;
    text-decoration: none;
    color: var(--text-secondary);
    padding: 0.75rem 1.5rem;
    border: 1px solid var(--border);
    border-radius: 4px;
    transition: all 0.3s ease;
}

.cta-link:hover {
    color: var(--accent);
    border-color: var(--accent);
}

.cta-link.primary {
    background-color: var(--accent);
    color: white;
    border-color: var(--accent);
}

.cta-link.primary:hover {
    opacity: 0.9;
}

.divider {
    color: var(--text-tertiary);
}

/* Section Header */
.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 3rem;
}

.section-header h2 {
    font-size: 2rem;
    font-weight: 700;
}

.view-all {
    font-size: 0.85rem;
    color: var(--text-secondary);
    text-decoration: none;
    transition: color 0.3s ease;
}

.view-all:hover {
    color: var(--accent);
}

/* Experience Section */
.experience-section {
    padding: 4rem 0;
    border-top: 1px solid var(--border);
}

.timeline {
    margin-top: 2rem;
}

.timeline-entry {
    display: flex;
    margin-bottom: 3rem;
    gap: 2rem;
}

.timeline-date {
    font-size: 0.75rem;
    font-weight: 600;
    letter-spacing: 0.1em;
    color: var(--text-tertiary);
    min-width: 140px;
    flex-shrink: 0;
}

.timeline-item h3 {
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.timeline-item .role {
    font-size: 0.95rem;
    color: var(--text-secondary);
    font-weight: 500;
    margin-bottom: 1rem;
}

.timeline-item .description {
    color: var(--text-secondary);
    line-height: 1.7;
}

/* Work Section */
.work-section {
    padding: 4rem 0;
    border-top: 1px solid var(--border);
}

.work-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.work-card {
    padding: 2rem;
    border: 1px solid var(--border);
    border-radius: 8px;
    transition: all 0.3s ease;
}

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

.work-card.featured {
    background-color: var(--bg-secondary);
}

.work-card .badge {
    font-size: 0.7rem;
    font-weight: 700;
    letter-spacing: 0.1em;
    color: var(--accent);
    text-transform: uppercase;
    margin-bottom: 1rem;
}

.work-card h3 {
    font-size: 1.3rem;
    font-weight: 700;
    margin-bottom: 1rem;
    line-height: 1.3;
}

.work-card p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    line-height: 1.7;
}

.tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.tags span {
    font-size: 0.75rem;
    padding: 0.4rem 0.8rem;
    background-color: var(--bg);
    border: 1px solid var(--border);
    border-radius: 4px;
    color: var(--text-tertiary);
}

/* Practices Section */
.practices-section {
    padding: 4rem 0;
    border-top: 1px solid var(--border);
}

.practices-section h2 {
    font-size: 1.8rem;
    margin-bottom: 3rem;
    text-align: left;
}

.practices-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
}

.practice {
    padding: 2rem;
    background-color: var(--bg-secondary);
    border-radius: 8px;
}

.practice h4 {
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--text);
}

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

/* Skills Section */
.skills-section {
    padding: 4rem 0;
    border-top: 1px solid var(--border);
}

.skills-section h2 {
    font-size: 1.8rem;
    margin-bottom: 3rem;
    text-align: left;
}

.skills {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

/* About Section */
.about-section {
    padding: 4rem 0;
    border-top: 1px solid var(--border);
}

.about-section h2 {
    font-size: 1.8rem;
    margin-bottom: 2rem;
    text-align: left;
}

/* Expertise Section */
.expertise-section {
    padding: 4rem 0;
    border-top: 1px solid var(--border);
}

.expertise-section h2 {
    font-size: 1.8rem;
    margin-bottom: 3rem;
    text-align: left;
}

.expertise-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.expertise-item {
    padding: 2rem;
    background-color: var(--bg-secondary);
    border-radius: 8px;
    transition: all 0.3s ease;
}

.expertise-item:hover {
    background-color: var(--border);
}

.expertise-item h3 {
    font-size: 1rem;
    font-weight: 700;
    margin-bottom: 0.75rem;
    color: var(--accent);
}

.expertise-item p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

/* Skills Section Grid */
.skills-section {
    padding: 4rem 0;
    border-top: 1px solid var(--border);
}

.skills-section h2 {
    font-size: 1.8rem;
    margin-bottom: 3rem;
}

.skills-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
}

.skill-column {
    padding: 2rem;
    background-color: var(--bg-secondary);
    border-radius: 8px;
}

.skill-column h4 {
    font-size: 0.95rem;
    font-weight: 700;
    margin-bottom: 0.75rem;
    color: var(--accent);
}

.skill-column p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.6;
}

.skill-group {
    padding-bottom: 1.5rem;
}

.skill-group h5 {
    font-size: 0.95rem;
    font-weight: 700;
    margin-bottom: 0.75rem;
    color: var(--accent);
}

.skill-group p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    line-height: 1.7;
}

/* Contact Section */
.contact-section {
    padding: 4rem 0;
    border-top: 1px solid var(--border);
    text-align: center;
}

.contact-section h2 {
    font-size: 2rem;
    margin-bottom: 1rem;
}

.contact-section p {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

.contact-links {
    display: flex;
    justify-content: center;
    gap: 2rem;
    flex-wrap: wrap;
}

.contact-link {
    font-size: 0.85rem;
    font-weight: 600;
    text-decoration: none;
    color: var(--text-secondary);
    padding: 0.75rem 1.5rem;
    border: 1px solid var(--border);
    border-radius: 4px;
    transition: all 0.3s ease;
}

.contact-link:hover {
    background-color: var(--accent);
    color: white;
    border-color: var(--accent);
}

/* Footer */
.footer {
    padding: 2rem 0;
    border-top: 1px solid var(--border);
    text-align: center;
    color: var(--text-tertiary);
    font-size: 0.9rem;
    margin-top: 4rem;
}

.footer a {
    color: var(--accent);
    text-decoration: none;
    transition: opacity 0.3s ease;
}

.footer a:hover {
    opacity: 0.8;
}

/* Animations */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

@keyframes fadeInLeft {
    from {
        opacity: 0;
        transform: translateX(-30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes fadeInRight {
    from {
        opacity: 0;
        transform: translateX(30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

@keyframes scaleIn {
    from {
        opacity: 0;
        transform: scale(0.95);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

@keyframes float {
    0%, 100% { transform: translateY(0px); }
    50% { transform: translateY(-20px); }
}

@keyframes slideUp {
    from {
        transform: translateY(50px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

/* Animation utility classes */
.animate-on-scroll {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease-out, transform 0.6s ease-out;
}

.animate-on-scroll.visible {
    opacity: 1;
    transform: translateY(0);
}

.fade-in-up {
    animation: fadeInUp 0.8s ease-out both;
}

.fade-in-left {
    animation: fadeInLeft 0.8s ease-out both;
}

.fade-in-right {
    animation: fadeInRight 0.8s ease-out both;
}

.scale-in {
    animation: scaleIn 0.8s ease-out both;
}

.float {
    animation: float 8s ease-in-out infinite;
}

/* Responsive */
@media (max-width: 768px) {
    .nav-menu {
        gap: 1rem;
        font-size: 0.7rem;
    }

    .hero h1 {
        font-size: 2rem;
    }

    .tagline {
        font-size: 1rem;
    }

    .section-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 1rem;
    }

    .timeline-entry {
        flex-direction: column;
        gap: 0.5rem;
    }

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

    .work-grid {
        grid-template-columns: 1fr;
    }

    main {
        padding: 0 1rem;
    }

    .hero {
        padding: 3rem 0;
    }

    .cta-links {
        flex-direction: column;
    }

    .cta-link {
        width: 100%;
    }

    .contact-links {
        flex-direction: column;
        gap: 1rem;
    }

    .contact-link {
        display: block;
        width: 100%;
    }
}

@media (max-width: 480px) {
    .hero h1 {
        font-size: 1.5rem;
    }

    .tagline {
        font-size: 0.95rem;
    }

    .nav-container {
        padding: 1rem;
    }

    .nav-menu {
        display: none;
    }
}