:root {
    --primary-color: #1e40af;
    --secondary-color: #3b82f6;
    --accent-color: #f59e0b;
    --text-dark: #1f2937;
    --text-light: #6b7280;
    --bg-light: #f9fafb;
    --bg-white: #ffffff;
    --border-color: #e5e7eb;
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px 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);
}

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

html {
    scroll-behavior: smooth;
}

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

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Navigation */
.navbar {
    background: var(--bg-white);
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
    padding: 1rem 0;
}

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

.nav-brand {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--primary-color);
}

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

.nav-menu a {
    color: var(--text-dark);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s;
}

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

/* Hero Section */
.hero {
    background: linear-gradient(135deg, #1e40af 0%, #3b82f6 100%);
    color: white;
    padding: 6rem 0;
    text-align: center;
}

.hero h1 {
    font-size: 3rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.credentials {
    font-size: 1.1rem;
    margin-bottom: 0.5rem;
    opacity: 0.95;
}

.tagline {
    font-size: 1.3rem;
    margin-bottom: 2rem;
    opacity: 0.9;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    margin-top: 2rem;
}

.btn {
    padding: 0.875rem 2rem;
    border-radius: 0.5rem;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s;
    display: inline-block;
}

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

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

.btn-secondary {
    background: transparent;
    color: white;
    border: 2px solid white;
}

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

/* Sections */
.section {
    padding: 5rem 0;
}

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

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 3rem;
    color: var(--primary-color);
}

/* About Section */
.about-content {
    max-width: 900px;
    margin: 0 auto;
    font-size: 1.1rem;
    line-height: 1.8;
    color: var(--text-light);
}

.about-content p {
    margin-bottom: 1.5rem;
}

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

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

.timeline-item {
    position: relative;
    padding-left: 60px;
    margin-bottom: 3rem;
}

.timeline-marker {
    position: absolute;
    left: 11px;
    top: 5px;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--primary-color);
    border: 4px solid var(--bg-light);
}

.timeline-content h3 {
    font-size: 1.4rem;
    color: var(--primary-color);
    margin-bottom: 0.5rem;
}

.institution {
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 0.25rem;
}

.details {
    color: var(--accent-color);
    font-weight: 500;
}

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

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

.award-card {
    background: var(--bg-white);
    padding: 2rem;
    border-radius: 0.5rem;
    box-shadow: var(--shadow);
    transition: transform 0.3s;
}

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

.award-year {
    display: inline-block;
    background: var(--primary-color);
    color: white;
    padding: 0.25rem 0.75rem;
    border-radius: 0.25rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.award-card h3 {
    color: var(--primary-color);
    font-size: 1.3rem;
    margin-bottom: 0.5rem;
}

.award-org {
    font-weight: 600;
    color: var(--text-dark);
    margin-bottom: 0.5rem;
}

.award-card p:last-child {
    color: var(--text-light);
    line-height: 1.6;
}

/* Experience Section */
.experience-list {
    max-width: 900px;
    margin: 0 auto;
}

.experience-item {
    background: var(--bg-white);
    padding: 2rem;
    margin-bottom: 1.5rem;
    border-radius: 0.5rem;
    border-left: 4px solid var(--primary-color);
    box-shadow: var(--shadow);
    transition: all 0.3s;
}

.experience-item:hover {
    transform: translateX(5px);
    box-shadow: var(--shadow-lg);
}

.experience-item.highlight {
    border-left-color: var(--accent-color);
    background: linear-gradient(to right, #fffbeb 0%, var(--bg-white) 100%);
}

.exp-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: 1rem;
}

.experience-item h3 {
    color: var(--primary-color);
    font-size: 1.3rem;
    margin-bottom: 0.5rem;
}

.company {
    font-weight: 600;
    color: var(--text-dark);
}

.details {
    color: var(--text-light);
    font-style: italic;
}

.exp-header .date {
    white-space: nowrap;
    color: var(--text-light);
    font-weight: 600;
}

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

.skill-category {
    background: var(--bg-white);
    padding: 2rem;
    border-radius: 0.5rem;
    box-shadow: var(--shadow);
}

.skill-category h3 {
    color: var(--primary-color);
    font-size: 1.4rem;
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--primary-color);
}

.skill-category ul {
    list-style: none;
}

.skill-category li {
    padding: 0.5rem 0;
    padding-left: 1.5rem;
    position: relative;
    color: var(--text-light);
}

.skill-category li::before {
    content: '▹';
    position: absolute;
    left: 0;
    color: var(--primary-color);
    font-weight: 700;
}

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

.cert-card {
    background: var(--bg-white);
    padding: 2rem;
    border-radius: 0.5rem;
    box-shadow: var(--shadow);
    text-align: center;
    transition: transform 0.3s;
}

.cert-card:hover {
    transform: scale(1.05);
}

.cert-card h3 {
    color: var(--primary-color);
    font-size: 1.5rem;
    margin-bottom: 0.5rem;
}

.cert-card p {
    color: var(--text-light);
    margin-bottom: 0.25rem;
}

.cert-org {
    font-weight: 600;
    color: var(--text-dark);
}

/* Projects Section */
.projects-list {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 1.5rem;
}

.project-item {
    background: var(--bg-white);
    padding: 1.5rem;
    border-radius: 0.5rem;
    box-shadow: var(--shadow);
    border-top: 3px solid var(--primary-color);
    transition: all 0.3s;
}

.project-item:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.project-item h3 {
    color: var(--primary-color);
    font-size: 1.2rem;
    margin-bottom: 0.75rem;
}

.project-item p {
    color: var(--text-light);
    line-height: 1.6;
}

/* Contact Section */
.contact-section {
    background: linear-gradient(135deg, #1e40af 0%, #3b82f6 100%);
    color: white;
}

.contact-section .section-title {
    color: white;
}

.contact-info {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    max-width: 900px;
    margin: 0 auto;
}

.contact-item {
    text-align: center;
}

.contact-item h3 {
    font-size: 1.3rem;
    margin-bottom: 0.5rem;
    opacity: 0.9;
}

.contact-item a {
    color: white;
    text-decoration: none;
    font-size: 1.1rem;
    font-weight: 500;
    transition: opacity 0.3s;
}

.contact-item a:hover {
    opacity: 0.8;
    text-decoration: underline;
}

.contact-item p {
    font-size: 1.1rem;
}

/* Footer */
footer {
    background: var(--text-dark);
    color: white;
    text-align: center;
    padding: 2rem 0;
}

/* Responsive Design */
@media (max-width: 768px) {
    .hero h1 {
        font-size: 2rem;
    }

    .tagline {
        font-size: 1.1rem;
    }

    .nav-menu {
        flex-direction: column;
        gap: 0.5rem;
    }

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

    .section-title {
        font-size: 2rem;
    }

    .exp-header {
        flex-direction: column;
    }

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

    .timeline-item {
        padding-left: 50px;
    }

    .timeline-marker {
        left: 1px;
    }
}

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

    .credentials {
        font-size: 0.9rem;
    }

    .section {
        padding: 3rem 0;
    }
}