:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --primary-light: #3b82f6;
    --text: #1f2937;
    --text-light: #6b7280;
    --text-lighter: #9ca3af;
    --bg: #ffffff;
    --bg-alt: #f9fafb;
    --border: #e5e7eb;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --radius: 8px;
    --radius-lg: 12px;
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    color: var(--text);
    background: var(--bg);
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* Navbar */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--border);
    z-index: 1000;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
    height: 64px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.nav-logo {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary);
    text-decoration: none;
}

.nav-avatar {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    object-fit: cover;
    border: 2px solid var(--primary);
}

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

.nav-links a {
    text-decoration: none;
    color: var(--text-light);
    font-size: 0.9rem;
    font-weight: 500;
    transition: color 0.2s;
}

.nav-links a:hover {
    color: var(--primary);
}

.lang-toggle {
    background: var(--primary);
    color: white;
    border: none;
    padding: 8px 16px;
    border-radius: var(--radius);
    font-weight: 600;
    font-size: 0.85rem;
    cursor: pointer;
    transition: background 0.2s;
}

.lang-toggle:hover {
    background: var(--primary-dark);
}

.mobile-menu-btn {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 5px;
}

.mobile-menu-btn span {
    width: 24px;
    height: 2px;
    background: var(--text);
    transition: 0.2s;
}

/* Hero Section */
.hero {
    min-height: auto;
    display: flex;
    align-items: center;
    padding: 100px 24px 60px;
    background: linear-gradient(135deg, #f0f7ff 0%, #ffffff 100%);
}

.hero-content {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    align-items: center;
}

.hero-greeting {
    font-size: 1.1rem;
    color: var(--primary);
    font-weight: 500;
    margin-bottom: 8px;
}

.hero-name {
    font-size: 3.5rem;
    font-weight: 700;
    color: var(--text);
    margin-bottom: 12px;
    line-height: 1.1;
}

.hero-title {
    font-size: 1.5rem;
    font-weight: 500;
    color: var(--text-light);
    margin-bottom: 20px;
}

.hero-description {
    font-size: 1.1rem;
    color: var(--text-light);
    margin-bottom: 32px;
    max-width: 500px;
}

.hero-buttons {
    display: flex;
    gap: 16px;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 14px 28px;
    border-radius: var(--radius);
    font-weight: 600;
    font-size: 1rem;
    text-decoration: none;
    transition: all 0.2s;
}

.btn-primary {
    background: var(--primary);
    color: white;
}

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn-secondary {
    background: white;
    color: var(--text);
    border: 2px solid var(--border);
}

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

.hero-image {
    display: flex;
    justify-content: center;
}

.profile-image {
    width: 350px;
    height: 350px;
    border-radius: 50%;
    object-fit: cover;
    object-position: center top;
    box-shadow: var(--shadow-lg);
    border: 6px solid white;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
}

/* Sections */
.section {
    padding: 60px 24px;
}

.section-alt {
    background: var(--bg-alt);
}

.section-title {
    font-size: 2rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 40px;
    position: relative;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -12px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 4px;
    background: var(--primary);
    border-radius: 2px;
}

/* Timeline */
.timeline {
    max-width: 800px;
    margin: 0 auto;
}

.timeline-item {
    display: grid;
    grid-template-columns: 180px 1fr;
    gap: 40px;
    margin-bottom: 48px;
    position: relative;
}

.timeline-item:not(:last-child)::before {
    content: '';
    position: absolute;
    left: 192px;
    top: 24px;
    bottom: -56px;
    width: 2px;
    background: var(--border);
}

.timeline-item::after {
    content: '';
    position: absolute;
    left: 184px;
    top: 8px;
    width: 12px;
    height: 12px;
    background: var(--primary);
    border-radius: 50%;
    border: 3px solid var(--bg);
    box-shadow: var(--shadow);
}

.timeline-date {
    text-align: right;
    padding-top: 4px;
}

.timeline-date span {
    font-size: 0.9rem;
    color: var(--text-light);
    font-weight: 500;
}

.timeline-content h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 4px;
}

.timeline-content h4 {
    font-size: 1rem;
    color: var(--primary);
    font-weight: 500;
    margin-bottom: 12px;
}

.timeline-content .role-context {
    font-style: italic;
    font-size: 0.9rem;
    color: var(--text-light);
    margin-bottom: 16px;
    line-height: 1.5;
}

.timeline-content ul {
    list-style: none;
}

.timeline-content li {
    position: relative;
    padding-left: 20px;
    margin-bottom: 8px;
    color: var(--text-light);
    font-size: 0.95rem;
}

.timeline-content li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 10px;
    width: 6px;
    height: 6px;
    background: var(--primary-light);
    border-radius: 50%;
}

/* Education */
.education-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 24px;
}

.education-card {
    background: var(--bg);
    padding: 32px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    transition: transform 0.2s, box-shadow 0.2s;
}

.education-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.education-icon {
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, #e0e7ff 0%, #c7d2fe 100%);
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 16px;
    color: var(--primary);
}

.education-date {
    font-size: 0.85rem;
    color: var(--text-lighter);
    font-weight: 500;
}

.education-card h3 {
    font-size: 1.1rem;
    font-weight: 600;
    margin: 8px 0 4px;
}

.education-card h4 {
    font-size: 0.95rem;
    color: var(--primary);
    font-weight: 500;
    margin-bottom: 8px;
}

.education-card p {
    font-size: 0.9rem;
    color: var(--text-light);
}

/* Projects */
.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(340px, 1fr));
    gap: 24px;
}

.project-card {
    background: var(--bg);
    border: 1px solid var(--border);
    padding: 28px;
    border-radius: var(--radius-lg);
    transition: transform 0.2s, box-shadow 0.2s;
}

.project-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--primary-light);
}

.project-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 12px;
}

.project-date {
    font-size: 0.85rem;
    color: var(--text-lighter);
}

.project-tag {
    font-size: 0.75rem;
    padding: 4px 10px;
    background: linear-gradient(135deg, #e0e7ff 0%, #c7d2fe 100%);
    color: var(--primary-dark);
    border-radius: 20px;
    font-weight: 500;
}

.project-card h3 {
    font-size: 1.15rem;
    font-weight: 600;
    margin-bottom: 12px;
}

.project-card p {
    font-size: 0.9rem;
    color: var(--text-light);
    margin-bottom: 16px;
}

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

.project-tech span {
    font-size: 0.75rem;
    padding: 4px 10px;
    background: var(--bg-alt);
    color: var(--text-light);
    border-radius: var(--radius);
    font-weight: 500;
}

/* Skills */
.skills-container {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 32px;
}

.skill-category {
    background: var(--bg);
    padding: 28px;
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
}

.skill-category h3 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 20px;
    padding-bottom: 12px;
    border-bottom: 2px solid var(--border);
}

.skill-items {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.skill-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.skill-name {
    font-size: 0.95rem;
    color: var(--text);
}

.skill-level {
    font-size: 0.85rem;
    color: var(--text-light);
    padding: 2px 10px;
    background: var(--bg-alt);
    border-radius: var(--radius);
}

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

.tech-tag {
    font-size: 0.85rem;
    padding: 6px 12px;
    background: linear-gradient(135deg, #e0e7ff 0%, #c7d2fe 100%);
    color: var(--primary-dark);
    border-radius: var(--radius);
    font-weight: 500;
}

.certification-item {
    display: flex;
    align-items: center;
    gap: 12px;
}

.cert-badge {
    font-size: 0.75rem;
    padding: 4px 10px;
    background: var(--primary);
    color: white;
    border-radius: var(--radius);
    font-weight: 600;
}

.interests-list {
    display: flex;
    flex-direction: column;
    gap: 16px;
}

.interest-item {
    display: flex;
    align-items: flex-start;
    gap: 12px;
}

.interest-icon {
    font-size: 1.5rem;
}

.interest-item strong {
    font-size: 0.95rem;
    display: block;
}

.interest-item p {
    font-size: 0.85rem;
    color: var(--text-light);
}

/* Contact */
.contact-content {
    max-width: 700px;
    margin: 0 auto;
    text-align: center;
}

.contact-intro {
    font-size: 1.2rem;
    color: var(--text-light);
    margin-bottom: 40px;
}

.contact-cards {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
}

.contact-card {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 20px 24px;
    background: var(--bg-alt);
    border-radius: var(--radius-lg);
    text-decoration: none;
    color: var(--text);
    transition: all 0.2s;
}

.contact-card:hover {
    background: var(--primary);
    color: white;
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.contact-card svg {
    flex-shrink: 0;
}

.contact-card span {
    font-size: 0.9rem;
    font-weight: 500;
}

/* Footer */
.footer {
    background: var(--text);
    color: var(--text-lighter);
    padding: 32px 24px;
    text-align: center;
}

.footer p {
    font-size: 0.9rem;
}

/* Mobile Responsive */
@media (max-width: 900px) {
    .nav-links {
        display: none;
        position: absolute;
        top: 64px;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: 24px;
        gap: 16px;
        border-bottom: 1px solid var(--border);
        box-shadow: var(--shadow-md);
    }

    .nav-links.active {
        display: flex;
    }

    .mobile-menu-btn {
        display: flex;
    }

    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .hero-name {
        font-size: 2.5rem;
    }

    .hero-title {
        font-size: 1.25rem;
    }

    .hero-description {
        margin: 0 auto 32px;
    }

    .hero-buttons {
        justify-content: center;
    }

    .hero-image {
        order: -1;
    }

    .profile-image {
        width: 250px;
        height: 250px;
    }

    .timeline-item {
        grid-template-columns: 1fr;
        gap: 8px;
        padding-left: 32px;
        margin-bottom: 40px;
    }

    .timeline-item:not(:last-child)::before {
        left: 8px;
        top: 0;
        bottom: -40px;
    }

    .timeline-item::after {
        left: 0;
        top: 0;
    }

    .timeline-date {
        text-align: left;
    }

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

    .contact-cards {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 480px) {
    .hero-buttons {
        flex-direction: column;
        width: 100%;
    }

    .btn {
        width: 100%;
    }

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

    .skills-container {
        grid-template-columns: 1fr;
    }
}