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

:root {
    --color-primary: #1a365d;
    --color-primary-light: #2c5282;
    --color-accent: #3182ce;
    --color-text: #2d3748;
    --color-text-light: #4a5568;
    --color-text-muted: #718096;
    --color-bg: #ffffff;
    --color-bg-alt: #f7fafc;
    --color-bg-card: #ffffff;
    --color-border: #e2e8f0;
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 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);
    --transition: all 0.3s ease;
}

html {
    scroll-behavior: smooth;
}

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

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 24px;
}

/* Typography */
h1, h2, h3, h4 {
    font-weight: 600;
    line-height: 1.3;
    color: var(--color-primary);
}

h1 { font-size: 3rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.25rem; }
h4 { font-size: 1.1rem; }

p {
    margin-bottom: 1rem;
}

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

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

ul {
    list-style: none;
}

/* Navigation */
.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(--color-border);
    z-index: 1000;
}

.nav-container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 64px;
    position: relative;
}

.nav-logo {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--color-primary);
    letter-spacing: -0.3px;
}

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

.nav-menu a {
    font-size: 0.9rem;
    font-weight: 500;
    color: var(--color-text-light);
    padding: 8px 0;
    position: relative;
}

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--color-accent);
    transition: var(--transition);
}

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

.nav-menu a:hover::after {
    width: 100%;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 4px;
    position: absolute;
    right: 24px;
}

.nav-toggle span {
    width: 24px;
    height: 2px;
    background: var(--color-text);
    transition: var(--transition);
}

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding: 100px 24px 60px;
    background: linear-gradient(135deg, var(--color-bg) 0%, var(--color-bg-alt) 100%);
}

.hero-content {
    max-width: 1100px;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 60px;
}

.hero-text {
    flex: 1;
}

.hero-image {
    flex-shrink: 0;
}

.hero-image img {
    width: 280px;
    height: 280px;
    object-fit: cover;
    border-radius: 50%;
    border: 4px solid white;
    box-shadow: var(--shadow-lg);
}

.hero-greeting {
    font-size: 1rem;
    color: var(--color-text-muted);
    margin-bottom: 8px;
    font-weight: 500;
}

.hero-name {
    font-size: clamp(2.5rem, 6vw, 4rem);
    font-weight: 700;
    color: var(--color-primary);
    margin-bottom: 20px;
    letter-spacing: -1px;
}

.hero-tagline {
    font-size: 1.2rem;
    color: var(--color-text-light);
    max-width: 600px;
    margin-bottom: 40px;
    line-height: 1.7;
}

.hero-stats {
    display: flex;
    gap: 48px;
    margin-bottom: 40px;
    flex-wrap: wrap;
}

.stat {
    display: flex;
    flex-direction: column;
}

.stat-number {
    font-size: 2rem;
    font-weight: 700;
    color: var(--color-primary);
    line-height: 1;
}

.stat-label {
    font-size: 0.85rem;
    color: var(--color-text-muted);
    margin-top: 4px;
}

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

.btn {
    display: inline-flex;
    align-items: center;
    padding: 12px 28px;
    border-radius: 6px;
    font-size: 0.95rem;
    font-weight: 500;
    transition: var(--transition);
    cursor: pointer;
}

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

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

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

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

/* Section Styles */
section {
    padding: 100px 0;
}

.section-title {
    font-size: 1.75rem;
    margin-bottom: 48px;
    position: relative;
    display: inline-block;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -12px;
    left: 0;
    width: 48px;
    height: 3px;
    background: var(--color-accent);
}

.subsection-title {
    font-size: 1.25rem;
    color: var(--color-primary);
    margin-bottom: 24px;
    margin-top: 48px;
}

/* About Section */
.about {
    background: var(--color-bg);
}

.about-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 60px;
    align-items: start;
}

.about-text p {
    color: var(--color-text-light);
    font-size: 1.05rem;
    line-height: 1.8;
}

.about-interests h3 {
    font-size: 1rem;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--color-text-muted);
    margin-bottom: 16px;
}

.interest-list li {
    padding: 8px 0;
    color: var(--color-text);
    font-size: 0.95rem;
    border-bottom: 1px solid var(--color-border);
}

.interest-list li:last-child {
    border-bottom: none;
}

/* Experience Section */
.experience {
    background: var(--color-bg-alt);
}

.experience-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 24px;
}

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

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

.experience-card.featured {
    grid-column: span 2;
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-primary-light) 100%);
    color: white;
    border: none;
}

.experience-card.featured h3,
.experience-card.featured .card-tag {
    color: white;
}

.experience-card.featured p,
.experience-card.featured li {
    color: rgba(255, 255, 255, 0.9);
}

.experience-card.featured .card-date {
    color: rgba(255, 255, 255, 0.7);
}

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

.card-tag {
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--color-accent);
}

.card-date {
    font-size: 0.8rem;
    color: var(--color-text-muted);
}

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

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

.card-highlights {
    font-size: 0.85rem;
}

.card-highlights li {
    padding: 4px 0;
    padding-left: 16px;
    position: relative;
    color: var(--color-text-muted);
}

.card-highlights li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 12px;
    width: 6px;
    height: 6px;
    background: var(--color-accent);
    border-radius: 50%;
}

.experience-card.featured .card-highlights li::before {
    background: rgba(255, 255, 255, 0.7);
}

/* Research Section */
.research {
    background: var(--color-bg);
}

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

.paper-card {
    background: var(--color-bg-alt);
    border-radius: 12px;
    padding: 28px;
    border-left: 4px solid var(--color-accent);
}

.paper-card h4 {
    font-size: 1.1rem;
    margin-bottom: 12px;
    color: var(--color-primary);
}

.paper-card p {
    font-size: 0.9rem;
    color: var(--color-text-light);
    margin-bottom: 0;
}

.programs-list {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.program-item {
    display: flex;
    gap: 20px;
    align-items: flex-start;
    padding: 20px;
    background: var(--color-bg-alt);
    border-radius: 12px;
}

.program-icon {
    width: 48px;
    height: 48px;
    background: var(--color-primary);
    color: white;
    border-radius: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.1rem;
    flex-shrink: 0;
}

.program-details h4 {
    font-size: 1rem;
    margin-bottom: 4px;
    color: var(--color-primary);
}

.program-date {
    font-size: 0.8rem;
    color: var(--color-text-muted);
    display: block;
    margin-bottom: 8px;
}

.program-details p {
    font-size: 0.9rem;
    color: var(--color-text-light);
    margin-bottom: 0;
}

/* Education Section */
.education {
    background: var(--color-bg-alt);
}

.education-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 24px;
}

.education-card {
    background: var(--color-bg-card);
    border-radius: 12px;
    padding: 28px;
    border: 1px solid var(--color-border);
}

.education-card h3 {
    font-size: 1.15rem;
    margin-bottom: 8px;
}

.education-card .school {
    font-size: 0.9rem;
    color: var(--color-text-muted);
    margin-bottom: 4px;
}

.education-card .grade {
    font-size: 0.9rem;
    color: var(--color-accent);
    font-weight: 500;
    margin-bottom: 20px;
}

.subjects {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 20px;
}

.subject-label {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    color: var(--color-text-muted);
    display: block;
    margin-bottom: 8px;
}

.subjects ul li {
    font-size: 0.9rem;
    padding: 4px 0;
    display: flex;
    justify-content: space-between;
    color: var(--color-text-light);
}

.subjects .score {
    font-weight: 600;
    color: var(--color-primary);
}

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

.igcse-grades p {
    margin-bottom: 8px;
}

.igcse-grades strong {
    color: var(--color-primary);
}

.grade-note {
    font-size: 0.8rem;
    color: var(--color-text-muted);
    font-style: italic;
    margin-top: 16px;
    margin-bottom: 0;
}

.achievements-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 24px;
}

.achievement {
    text-align: center;
    padding: 24px;
    background: var(--color-bg-card);
    border-radius: 12px;
    border: 1px solid var(--color-border);
}

.achievement-number {
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--color-primary);
    display: block;
    line-height: 1;
}

.achievement-icon {
    font-size: 2rem;
    color: var(--color-accent);
    display: block;
    line-height: 1;
    margin-bottom: 4px;
}

.achievement-label {
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--color-text);
    display: block;
    margin-top: 8px;
}

.achievement-detail {
    font-size: 0.8rem;
    color: var(--color-text-muted);
    display: block;
    margin-top: 4px;
}

.certifications-list {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.certifications-list li {
    padding: 12px 16px;
    background: var(--color-bg-card);
    border-radius: 8px;
    border: 1px solid var(--color-border);
    font-size: 0.9rem;
    color: var(--color-text-light);
}

/* Contact Section */
.contact {
    background: var(--color-primary);
    color: white;
    text-align: center;
}

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

.contact .section-title::after {
    background: rgba(255, 255, 255, 0.5);
    left: 50%;
    transform: translateX(-50%);
}

.contact-intro {
    font-size: 1.1rem;
    color: rgba(255, 255, 255, 0.8);
    max-width: 500px;
    margin: 0 auto 32px;
}

.contact-links {
    display: flex;
    justify-content: center;
    gap: 24px;
    flex-wrap: wrap;
}

.contact-link {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 16px 28px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 8px;
    color: white;
    font-size: 0.95rem;
    transition: var(--transition);
}

.contact-link:hover {
    background: rgba(255, 255, 255, 0.2);
    color: white;
}

.contact-icon {
    font-weight: 700;
    font-size: 1rem;
}

/* Footer */
.footer {
    background: var(--color-primary);
    color: rgba(255, 255, 255, 0.6);
    padding: 24px 0;
    text-align: center;
    font-size: 0.85rem;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

/* Responsive */
@media (max-width: 768px) {
    .nav-menu {
        position: fixed;
        top: 64px;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: 24px;
        gap: 16px;
        border-bottom: 1px solid var(--color-border);
        transform: translateY(-100%);
        opacity: 0;
        visibility: hidden;
        transition: var(--transition);
    }

    .nav-menu.active {
        transform: translateY(0);
        opacity: 1;
        visibility: visible;
    }

    .nav-toggle {
        display: flex;
    }

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

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

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

    .hero {
        padding: 100px 24px 60px;
    }

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

    .hero-image img {
        width: 200px;
        height: 200px;
    }

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

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

    .hero-stats {
        gap: 32px;
    }

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

    .btn {
        width: 100%;
        justify-content: center;
    }

    .about-content {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    .experience-card.featured {
        grid-column: span 1;
    }

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

    .contact-links {
        flex-direction: column;
        align-items: center;
    }

    .contact-link {
        width: 100%;
        max-width: 280px;
        justify-content: center;
    }
}

@media (max-width: 480px) {
    section {
        padding: 60px 0;
    }

    .section-title {
        font-size: 1.5rem;
    }

    h1 { font-size: 2rem; }

    .hero-tagline {
        font-size: 1rem;
    }

    .stat-number {
        font-size: 1.5rem;
    }

    .experience-card,
    .paper-card,
    .education-card,
    .program-item {
        padding: 20px;
    }
}