/* ===========================
   CSS Variables & Reset
   =========================== */
:root {
    --primary-color: #10b981;
    --primary-dark: #059669;
    --secondary-color: #14b8a6;
    --accent-color: #06b6d4;
    --text-dark: #1f2937;
    --text-light: #6b7280;
    --text-white: #ffffff;
    --bg-white: #ffffff;
    --bg-light: #f9fafb;
    --bg-dark: #111827;
    --bg-card: #ffffff;
    --border-color: #e5e7eb;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    --gradient-primary: linear-gradient(135deg, #10b981 0%, #059669 100%);
    --gradient-secondary: linear-gradient(135deg, #14b8a6 0%, #0d9488 100%);
    --gradient-accent: linear-gradient(135deg, #34d399 0%, #10b981 100%);
    --gradient-hero: linear-gradient(135deg, #10b981 0%, #059669 50%, #14b8a6 100%);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.7;
    color: var(--text-dark);
    background-color: var(--bg-light);
    overflow-x: hidden;
}

a {
    text-decoration: none;
    color: inherit;
    transition: all 0.3s ease;
}

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

/* ===========================
   Container & Layout
   =========================== */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

section {
    padding: 5rem 0;
}

/* ===========================
   Hero Section
   =========================== */
#hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
    background: var(--gradient-hero);
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 0;
}

.hero-image {
    width: 100%;
    height: 100%;
    object-fit: cover;
    opacity: 0.2;
}

.hero-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg,
        rgba(16, 185, 129, 0.95) 0%,
        rgba(5, 150, 105, 0.95) 50%,
        rgba(20, 184, 166, 0.9) 100%);
}

.hero-content {
    position: relative;
    z-index: 2;
    text-align: center;
    color: var(--text-white);
    padding: 2rem;
    animation: fadeInUp 1s ease-out;
}

.headshot {
    width: 200px;
    height: 200px;
    border-radius: 50%;
    object-fit: cover;
    margin: 0 auto 2rem;
    border: 6px solid rgba(255, 255, 255, 0.3);
    box-shadow: var(--shadow-xl);
    animation: scaleIn 0.8s ease-out;
}

.hero-title {
    font-size: 4rem;
    font-weight: 900;
    margin-bottom: 0.5rem;
    text-shadow: 2px 4px 8px rgba(0, 0, 0, 0.2);
}

.hero-subtitle {
    font-size: 1.5rem;
    font-weight: 300;
    margin-bottom: 1rem;
    opacity: 0.95;
}

.hero-tagline {
    font-size: 2rem;
    font-weight: 600;
    margin-bottom: 1rem;
    text-shadow: 1px 2px 4px rgba(0, 0, 0, 0.2);
}

.hero-description {
    font-size: 1.25rem;
    font-weight: 400;
    margin-bottom: 2rem;
    opacity: 0.9;
}

.cta-button {
    display: inline-block;
    padding: 1rem 2.5rem;
    background: var(--text-white);
    color: var(--primary-color);
    font-weight: 700;
    font-size: 1.1rem;
    border-radius: 50px;
    box-shadow: var(--shadow-xl);
    transition: all 0.3s ease;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.cta-button:hover {
    transform: translateY(-3px);
    box-shadow: 0 20px 40px -5px rgba(0, 0, 0, 0.3);
    background: var(--bg-light);
}

.cta-button-large {
    padding: 1.25rem 3rem;
    font-size: 1.2rem;
}

/* ===========================
   Section Titles
   =========================== */
.section-title {
    font-size: 3rem;
    font-weight: 800;
    text-align: center;
    margin-bottom: 1rem;
    background: var(--gradient-primary);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.section-subtitle {
    text-align: center;
    color: var(--text-light);
    font-size: 1.2rem;
    margin-bottom: 3rem;
}

/* ===========================
   Value Proposition Section
   =========================== */
#value-proposition {
    background: var(--bg-white);
}

.value-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.value-card {
    background: var(--bg-card);
    padding: 2.5rem;
    border-radius: 20px;
    box-shadow: var(--shadow-md);
    transition: all 0.3s ease;
    border: 1px solid var(--border-color);
}

.value-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-xl);
    border-color: var(--primary-color);
}

.value-icon {
    font-size: 4rem;
    margin-bottom: 1.5rem;
    text-align: center;
}

.value-card h3 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--text-dark);
}

.value-card p {
    color: var(--text-light);
    line-height: 1.8;
}

/* ===========================
   Technical Expertise Section
   =========================== */
#expertise {
    background: var(--bg-light);
}

.tech-categories {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.tech-category {
    background: var(--bg-white);
    padding: 2rem;
    border-radius: 15px;
    box-shadow: var(--shadow-sm);
}

.tech-category h3 {
    font-size: 1.3rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    color: var(--primary-color);
}

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

.tech-tag {
    display: inline-block;
    padding: 0.5rem 1rem;
    background: var(--gradient-accent);
    color: var(--text-white);
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 600;
    box-shadow: var(--shadow-sm);
    transition: all 0.3s ease;
}

.tech-tag:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

/* ===========================
   Experience Timeline
   =========================== */
#experience {
    background: var(--bg-white);
}

.timeline {
    position: relative;
    max-width: 900px;
    margin: 3rem auto;
    padding-left: 3rem;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    height: 100%;
    width: 4px;
    background: var(--gradient-primary);
    border-radius: 2px;
}

.timeline-item {
    position: relative;
    margin-bottom: 3rem;
}

.timeline-marker {
    position: absolute;
    left: -3.5rem;
    top: 0;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: var(--primary-color);
    border: 4px solid var(--bg-white);
    box-shadow: 0 0 0 4px var(--primary-color);
}

.timeline-content {
    background: var(--bg-card);
    padding: 2rem;
    border-radius: 15px;
    box-shadow: var(--shadow-md);
    transition: all 0.3s ease;
    border-left: 4px solid var(--primary-color);
}

.timeline-content:hover {
    transform: translateX(10px);
    box-shadow: var(--shadow-lg);
}

.timeline-date {
    display: inline-block;
    padding: 0.4rem 1rem;
    background: var(--gradient-primary);
    color: var(--text-white);
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.timeline-content h3 {
    font-size: 1.8rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: var(--text-dark);
}

.timeline-content h4 {
    font-size: 1.2rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-weight: 600;
}

.timeline-content p {
    color: var(--text-light);
    line-height: 1.8;
}

.highlight-badge {
    display: inline-block;
    margin-top: 1rem;
    padding: 0.5rem 1rem;
    background: var(--gradient-secondary);
    color: var(--text-white);
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

/* ===========================
   Publications Section
   =========================== */
#publications {
    background: var(--bg-light);
}

.publications-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.publication-card {
    background: var(--bg-white);
    padding: 2rem;
    border-radius: 15px;
    box-shadow: var(--shadow-md);
    transition: all 0.3s ease;
    border-top: 4px solid var(--accent-color);
}

.publication-card.featured {
    border-top: 4px solid var(--secondary-color);
    background: linear-gradient(135deg, rgba(20, 184, 166, 0.05) 0%, rgba(255, 255, 255, 1) 100%);
}

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

.publication-type {
    display: inline-block;
    padding: 0.4rem 0.8rem;
    background: var(--primary-color);
    color: var(--text-white);
    border-radius: 15px;
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 1rem;
}

.publication-card.featured .publication-type {
    background: var(--secondary-color);
}

.publication-card h3 {
    font-size: 1.2rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--text-dark);
    line-height: 1.4;
}

.authors {
    color: var(--text-light);
    font-size: 0.95rem;
    margin-bottom: 1rem;
    font-style: italic;
}

.publication-link {
    color: var(--primary-color);
    font-weight: 600;
    font-size: 0.9rem;
    transition: all 0.3s ease;
    display: inline-block;
}

.publication-link:hover {
    color: var(--primary-dark);
    transform: translateX(5px);
}

/* ===========================
   Education Section
   =========================== */
#education {
    background: var(--bg-white);
}

.education-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 3rem;
}

.education-card {
    background: var(--bg-card);
    padding: 2rem;
    border-radius: 15px;
    box-shadow: var(--shadow-md);
    border-left: 5px solid var(--primary-color);
    transition: all 0.3s ease;
}

.education-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
    border-left-color: var(--secondary-color);
}

.degree-year {
    display: inline-block;
    padding: 0.4rem 1rem;
    background: var(--primary-color);
    color: var(--text-white);
    border-radius: 20px;
    font-size: 0.9rem;
    font-weight: 600;
    margin-bottom: 1rem;
}

.education-card h3 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: var(--text-dark);
}

.education-card h4 {
    font-size: 1.1rem;
    color: var(--primary-color);
    margin-bottom: 1rem;
    font-weight: 600;
}

.education-card p {
    color: var(--text-light);
    line-height: 1.8;
}

/* ===========================
   Contact Form Section
   =========================== */
#contact-form-section {
    background: var(--gradient-hero);
    padding: 5rem 0;
}

#contact-form-section .section-title {
    color: var(--text-white);
    background: none;
    -webkit-text-fill-color: var(--text-white);
}

#contact-form-section .section-subtitle {
    color: rgba(255, 255, 255, 0.9);
}

.contact-wrapper {
    display: grid;
    grid-template-columns: 1.5fr 1fr;
    gap: 4rem;
    margin-top: 3rem;
    max-width: 1100px;
    margin-left: auto;
    margin-right: auto;
}

.contact-form {
    background: var(--bg-card);
    padding: 2.5rem;
    border-radius: 20px;
    box-shadow: var(--shadow-lg);
    border: 1px solid var(--border-color);
}

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 600;
    color: var(--text-dark);
    font-size: 0.95rem;
}

.form-group input,
.form-group textarea {
    width: 100%;
    padding: 0.875rem 1.25rem;
    border: 2px solid var(--border-color);
    border-radius: 10px;
    font-size: 1rem;
    font-family: inherit;
    transition: all 0.3s ease;
    background: var(--bg-white);
    color: var(--text-dark);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(16, 185, 129, 0.1);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

.contact-form button[type="submit"] {
    width: 100%;
    margin-top: 1rem;
}

.contact-info {
    background: var(--bg-light);
    padding: 2.5rem;
    border-radius: 20px;
    border-left: 5px solid var(--primary-color);
}

.contact-info h3 {
    font-size: 1.8rem;
    margin-bottom: 1rem;
    color: var(--text-dark);
}

.contact-info p {
    color: var(--text-light);
    margin-bottom: 1.5rem;
}

.direct-email {
    display: inline-block;
    color: var(--primary-color);
    font-weight: 700;
    font-size: 1.2rem;
    margin-bottom: 2.5rem;
    transition: all 0.3s ease;
}

.direct-email:hover {
    color: var(--primary-dark);
    transform: translateX(5px);
}

.contact-details {
    margin-top: 2.5rem;
    padding-top: 2rem;
    border-top: 2px solid var(--border-color);
}

.contact-details h4 {
    font-size: 1.2rem;
    margin-bottom: 0.75rem;
    color: var(--text-dark);
}

.contact-details p {
    color: var(--text-light);
    line-height: 1.8;
}

/* ===========================
   Footer Section
   =========================== */
#contact {
    background: #1f2937;
    color: var(--text-white);
    padding: 4rem 0 2rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 3rem;
    margin-bottom: 3rem;
}

.footer-main h3 {
    font-size: 1.8rem;
    margin-bottom: 1rem;
    margin-top: 1rem;
}

#logo {
    width: 120px;
    height: auto;
    margin-bottom: 1rem;
    filter: brightness(1.8) contrast(0.9);
    opacity: 0.95;
}

.footer-email {
    margin-top: 1rem;
}

.footer-email a {
    color: var(--accent-color);
    font-weight: 600;
    font-size: 1.1rem;
}

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

.footer-details {
    color: rgba(255, 255, 255, 0.8);
    line-height: 1.8;
}

.footer-link {
    display: inline-block;
    margin-top: 1rem;
    color: var(--accent-color);
    font-weight: 600;
}

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

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 2rem;
    text-align: center;
    color: rgba(255, 255, 255, 0.6);
}

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

@keyframes scaleIn {
    from {
        opacity: 0;
        transform: scale(0.8);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

.fade-in {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.6s ease, transform 0.6s ease;
}

.fade-in-visible {
    opacity: 1;
    transform: translateY(0);
}

/* ===========================
   Responsive Design
   =========================== */
@media (max-width: 768px) {
    .hero-title {
        font-size: 2.5rem;
    }

    .hero-tagline {
        font-size: 1.5rem;
    }

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

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

    .headshot {
        width: 150px;
        height: 150px;
    }

    .timeline {
        padding-left: 2rem;
    }

    .timeline-marker {
        left: -2.4rem;
        width: 16px;
        height: 16px;
    }

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

    .tech-categories {
        grid-template-columns: 1fr;
    }

    .contact-wrapper {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .form-row {
        grid-template-columns: 1fr;
        gap: 1rem;
    }

    .cta-button {
        padding: 0.875rem 2rem;
        font-size: 1rem;
    }

    section {
        padding: 3rem 0;
    }

    .container {
        padding: 0 1.5rem;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }

    .hero-tagline {
        font-size: 1.2rem;
    }

    .value-icon {
        font-size: 3rem;
    }

    .timeline-content h3 {
        font-size: 1.4rem;
    }
}