/* ===== CSS Variables ===== */
:root {
    --primary: #2563eb;
    --primary-dark: #1d4ed8;
    --secondary: #64748b;
    --text: #1e293b;
    --text-light: #64748b;
    --background: #ffffff;
    --background-alt: #f8fafc;
    --border: #e2e8f0;
    --success: #10b981;
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --shadow: 0 1px 3px rgba(0,0,0,0.1), 0 1px 2px rgba(0,0,0,0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.1), 0 4px 6px -2px rgba(0,0,0,0.05);
    --transition: all 0.3s ease;
    --max-width: 1200px;
}

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

html {
    scroll-behavior: smooth;
}

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

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

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

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

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

/* ===== Typography ===== */
h1, h2, h3, h4 {
    font-weight: 700;
    line-height: 1.2;
    color: var(--text);
}

h1 { font-size: 3rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.25rem; }

.section-title {
    text-align: center;
    margin-bottom: 48px;
    position: relative;
}

.section-title::after {
    content: '';
    display: block;
    width: 60px;
    height: 4px;
    background: var(--primary);
    margin: 16px auto 0;
    border-radius: 2px;
}

/* ===== Buttons ===== */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 24px;
    font-size: 1rem;
    font-weight: 600;
    border-radius: 8px;
    cursor: pointer;
    transition: var(--transition);
    border: 2px solid transparent;
}

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

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

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

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

/* ===== Navigation ===== */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    z-index: 1000;
    box-shadow: var(--shadow);
}

.nav-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 16px 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text);
}

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

.nav-menu {
    display: flex;
    list-style: none;
    gap: 32px;
}

.nav-link {
    color: var(--text);
    font-weight: 500;
    font-size: 0.95rem;
}

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

.hamburger {
    display: none;
    flex-direction: column;
    gap: 5px;
    cursor: pointer;
}

.bar {
    width: 25px;
    height: 3px;
    background: var(--text);
    border-radius: 2px;
    transition: var(--transition);
}

/* ===== Hero Section ===== */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: 120px 0 80px;
    background: linear-gradient(135deg, #f8fafc 0%, #e2e8f0 100%);
}

.hero-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 24px;
}

.hero-greeting {
    font-size: 1.1rem;
    color: var(--primary);
    font-weight: 600;
    margin-bottom: 8px;
}

.hero-title {
    font-size: 3.5rem;
    margin-bottom: 16px;
    background: linear-gradient(135deg, var(--text) 0%, var(--primary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.5rem;
    color: var(--secondary);
    font-weight: 500;
    margin-bottom: 24px;
}

.hero-description {
    font-size: 1.1rem;
    color: var(--text-light);
    max-width: 600px;
    margin-bottom: 32px;
    line-height: 1.8;
}

.hero-cta {
    display: flex;
    gap: 16px;
    margin-bottom: 48px;
    flex-wrap: wrap;
}

.hero-stats {
    display: flex;
    gap: 48px;
    flex-wrap: wrap;
}

.stat {
    text-align: center;
}

.stat-number {
    display: block;
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--primary);
}

.stat-label {
    font-size: 0.9rem;
    color: var(--text-light);
}

/* ===== About Section ===== */
.about {
    padding: 100px 0;
    background: var(--background);
}

.about-content {
    max-width: 800px;
    margin: 0 auto;
}

.about-text p {
    margin-bottom: 20px;
    font-size: 1.1rem;
    color: var(--text-light);
}

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

.about-cta {
    margin-top: 32px;
}

/* ===== Expertise Section ===== */
.expertise {
    padding: 100px 0;
    background: var(--background-alt);
}

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

.expertise-card {
    background: var(--background);
    padding: 32px;
    border-radius: 12px;
    box-shadow: var(--shadow);
    transition: var(--transition);
}

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

.expertise-icon {
    width: 56px;
    height: 56px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 20px;
    color: white;
}

.expertise-card h3 {
    margin-bottom: 12px;
}

.expertise-card p {
    color: var(--text-light);
    font-size: 0.95rem;
}

/* ===== Projects Section ===== */
.projects {
    padding: 100px 0;
    background: var(--background);
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
    margin-bottom: 48px;
}

.project-card {
    background: var(--background-alt);
    padding: 28px;
    border-radius: 12px;
    border: 1px solid var(--border);
    transition: var(--transition);
}

.project-card:hover {
    border-color: var(--primary);
    box-shadow: var(--shadow-lg);
}

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

.project-header h3 {
    flex: 1;
}

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

.project-card p {
    color: var(--text-light);
    margin-bottom: 16px;
    font-size: 0.95rem;
}

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

.project-tech span {
    background: var(--border);
    color: var(--text);
    padding: 4px 10px;
    border-radius: 4px;
    font-size: 0.8rem;
    font-weight: 500;
}

.projects-cta {
    text-align: center;
}

/* ===== Experience Section ===== */
.experience {
    padding: 100px 0;
    background: var(--background-alt);
}

.timeline {
    max-width: 800px;
    margin: 0 auto;
    position: relative;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 20px;
    top: 0;
    bottom: 0;
    width: 2px;
    background: var(--border);
}

.timeline-item {
    position: relative;
    padding-left: 60px;
    padding-bottom: 40px;
}

.timeline-item:last-child {
    padding-bottom: 0;
}

.timeline-marker {
    position: absolute;
    left: 12px;
    top: 4px;
    width: 18px;
    height: 18px;
    background: var(--primary);
    border-radius: 50%;
    border: 3px solid var(--background-alt);
}

.timeline-content {
    background: var(--background);
    padding: 24px;
    border-radius: 12px;
    box-shadow: var(--shadow);
}

.timeline-content h3 {
    color: var(--text);
    margin-bottom: 4px;
}

.timeline-role {
    color: var(--primary);
    font-weight: 600;
    margin-bottom: 4px;
}

.timeline-date {
    color: var(--text-light);
    font-size: 0.9rem;
    margin-bottom: 12px;
}

.timeline-content > p:last-child {
    color: var(--text-light);
    margin: 0;
}

/* ===== Contact Section ===== */
.contact {
    padding: 100px 0;
    background: var(--background);
}

.contact-content {
    max-width: 600px;
    margin: 0 auto;
    text-align: center;
}

.contact-intro {
    font-size: 1.1rem;
    color: var(--text-light);
    margin-bottom: 32px;
}

.contact-methods {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    gap: 16px;
    margin-bottom: 24px;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 12px 20px;
    background: var(--background-alt);
    border-radius: 8px;
    color: var(--text);
    font-weight: 500;
    transition: var(--transition);
}

.contact-item:hover {
    background: var(--primary);
    color: white;
}

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

.contact-location {
    color: var(--text-light);
    font-size: 0.95rem;
}

/* ===== Footer ===== */
.footer {
    padding: 32px 0;
    background: var(--text);
    color: white;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 16px;
}

.footer-content p {
    color: rgba(255,255,255,0.7);
    font-size: 0.9rem;
}

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

.footer-links a {
    color: rgba(255,255,255,0.7);
    font-size: 0.9rem;
}

.footer-links a:hover {
    color: white;
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
    h1, .hero-title { font-size: 2.5rem; }
    h2 { font-size: 1.75rem; }
    .hero-subtitle { font-size: 1.2rem; }

    .nav-menu {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: 24px;
        gap: 16px;
        box-shadow: var(--shadow-lg);
    }

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

    .hamburger {
        display: flex;
    }

    .hero-stats {
        gap: 24px;
    }

    .stat-number {
        font-size: 2rem;
    }

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

    .btn {
        width: 100%;
    }

    .footer-content {
        flex-direction: column;
        text-align: center;
    }

    .timeline::before {
        left: 10px;
    }

    .timeline-item {
        padding-left: 40px;
    }

    .timeline-marker {
        left: 2px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }

    section {
        padding: 60px 0;
    }

    .hero {
        padding: 100px 0 60px;
    }

    .expertise-card,
    .project-card,
    .timeline-content {
        padding: 20px;
    }
}