/* ===================================
   CSS Variables & Reset
   =================================== */
:root {
    /* Colors */
    --color-primary: #1a365d;
    --color-primary-light: #2c5282;
    --color-primary-dark: #0f2544;
    --color-accent: #3182ce;
    --color-accent-light: #63b3ed;

    --color-text: #1a202c;
    --color-text-light: #4a5568;
    --color-text-muted: #718096;

    --color-bg: #ffffff;
    --color-bg-alt: #f7fafc;
    --color-bg-dark: #1a202c;

    --color-border: #e2e8f0;
    --color-border-light: #edf2f7;

    /* Typography */
    --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-serif: 'Playfair Display', Georgia, serif;

    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 1.5rem;
    --space-xl: 2rem;
    --space-2xl: 3rem;
    --space-3xl: 4rem;
    --space-4xl: 6rem;

    /* Container */
    --container-max: 1200px;
    --container-narrow: 800px;

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
    --transition-slow: 400ms ease;

    /* Shadows */
    --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);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
}

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

html {
    scroll-behavior: smooth;
    -webkit-text-size-adjust: 100%;
}

body {
    font-family: var(--font-sans);
    font-size: 1rem;
    line-height: 1.6;
    color: var(--color-text);
    background-color: var(--color-bg);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

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

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

ul {
    list-style: none;
}

/* ===================================
   Typography
   =================================== */
h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-serif);
    font-weight: 600;
    line-height: 1.2;
    color: var(--color-primary);
}

h1 { font-size: clamp(2.5rem, 5vw, 4rem); }
h2 { font-size: clamp(1.75rem, 3vw, 2.5rem); }
h3 { font-size: clamp(1.25rem, 2vw, 1.5rem); }
h4 { font-size: 1.125rem; }

.lead {
    font-size: clamp(1.125rem, 2vw, 1.375rem);
    color: var(--color-text-light);
    line-height: 1.7;
}

/* ===================================
   Layout
   =================================== */
.container {
    width: 100%;
    max-width: var(--container-max);
    margin: 0 auto;
    padding: 0 var(--space-lg);
}

.section {
    padding: var(--space-4xl) 0;
}

.section-title {
    text-align: center;
    margin-bottom: var(--space-3xl);
    position: relative;
}

.section-title::after {
    content: '';
    display: block;
    width: 60px;
    height: 3px;
    background: var(--color-accent);
    margin: var(--space-md) auto 0;
}

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

.navbar.scrolled {
    border-bottom-color: var(--color-border);
    box-shadow: var(--shadow-sm);
}

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

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

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

.nav-menu {
    display: flex;
    align-items: center;
    gap: var(--space-xl);
}

.nav-link {
    font-size: 0.9375rem;
    font-weight: 500;
    color: var(--color-text-light);
    transition: color var(--transition-fast);
}

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

.nav-cta {
    background: var(--color-primary);
    color: white !important;
    padding: var(--space-sm) var(--space-lg);
    border-radius: 6px;
}

.nav-cta:hover {
    background: var(--color-primary-light);
    color: white !important;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    gap: 5px;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--space-sm);
}

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

/* ===================================
   Hero Section
   =================================== */
.hero {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: var(--space-4xl) var(--space-lg);
    background: linear-gradient(135deg, var(--color-bg) 0%, var(--color-bg-alt) 100%);
    position: relative;
}

.hero-content {
    max-width: 800px;
}

.hero-subtitle {
    font-size: 0.875rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.15em;
    color: var(--color-accent);
    margin-bottom: var(--space-md);
}

.hero-title {
    margin-bottom: var(--space-md);
    color: var(--color-primary);
}

.hero-tagline {
    font-size: 1.125rem;
    color: var(--color-text-muted);
    margin-bottom: var(--space-xl);
}

.hero-description {
    font-size: clamp(1rem, 2vw, 1.25rem);
    color: var(--color-text-light);
    max-width: 600px;
    margin: 0 auto var(--space-2xl);
    line-height: 1.8;
}

.hero-actions {
    display: flex;
    gap: var(--space-md);
    justify-content: center;
    flex-wrap: wrap;
}

.hero-scroll {
    position: absolute;
    bottom: var(--space-2xl);
    left: 50%;
    transform: translateX(-50%);
    animation: bounce 2s infinite;
}

.hero-scroll svg {
    width: 32px;
    height: 32px;
    color: var(--color-text-muted);
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% { transform: translateX(-50%) translateY(0); }
    40% { transform: translateX(-50%) translateY(-10px); }
    60% { transform: translateX(-50%) translateY(-5px); }
}

/* ===================================
   Buttons
   =================================== */
.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-md) var(--space-xl);
    font-family: var(--font-sans);
    font-size: 0.9375rem;
    font-weight: 500;
    border-radius: 8px;
    border: 2px solid transparent;
    cursor: pointer;
    transition: all var(--transition-base);
}

.btn-icon {
    width: 18px;
    height: 18px;
}

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

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

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

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

.btn-large {
    padding: var(--space-lg) var(--space-2xl);
    font-size: 1rem;
}

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

.about-content {
    max-width: var(--container-narrow);
    margin: 0 auto;
}

.about-intro {
    margin-bottom: var(--space-2xl);
    text-align: center;
}

.about-text p {
    margin-bottom: var(--space-lg);
    color: var(--color-text-light);
}

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

/* ===================================
   Philosophy Section
   =================================== */
.philosophy {
    background: var(--color-bg-alt);
}

.philosophy-content {
    max-width: var(--container-narrow);
    margin: 0 auto;
}

.philosophy-intro {
    text-align: center;
    margin-bottom: var(--space-2xl);
}

.philosophy-belief {
    margin-bottom: var(--space-2xl);
}

.belief-list {
    margin-top: var(--space-md);
    padding-left: var(--space-xl);
}

.belief-list li {
    position: relative;
    padding: var(--space-sm) 0;
    color: var(--color-text-light);
}

.belief-list li::before {
    content: '';
    position: absolute;
    left: -1.5rem;
    top: 50%;
    transform: translateY(-50%);
    width: 6px;
    height: 6px;
    background: var(--color-accent);
    border-radius: 50%;
}

.focus-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: var(--space-lg);
    margin-top: var(--space-xl);
}

.focus-item {
    background: var(--color-bg);
    padding: var(--space-xl);
    border-radius: 12px;
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-base);
}

.focus-item:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.focus-item h4 {
    font-family: var(--font-sans);
    font-weight: 600;
    margin-bottom: var(--space-sm);
}

.focus-item p {
    font-size: 0.9375rem;
    color: var(--color-text-muted);
}

.philosophy-quote {
    margin-top: var(--space-3xl);
    padding: var(--space-2xl);
    background: var(--color-primary);
    border-radius: 12px;
    text-align: center;
}

.philosophy-quote p {
    font-family: var(--font-serif);
    font-size: clamp(1.125rem, 2vw, 1.5rem);
    font-style: italic;
    color: white;
    line-height: 1.6;
}

/* ===================================
   AI Approach Section
   =================================== */
.ai-approach {
    background: var(--color-bg);
}

.ai-content {
    max-width: var(--container-narrow);
    margin: 0 auto;
}

.ai-content > p {
    color: var(--color-text-light);
    margin-bottom: var(--space-lg);
}

.ai-content .lead {
    text-align: center;
    margin-bottom: var(--space-2xl);
}

.ai-practice {
    background: var(--color-bg-alt);
    padding: var(--space-xl);
    border-radius: 12px;
    margin: var(--space-2xl) 0;
}

.ai-practice h3 {
    font-family: var(--font-sans);
    font-weight: 600;
    margin-bottom: var(--space-md);
}

.ai-list {
    padding-left: var(--space-xl);
}

.ai-list li {
    position: relative;
    padding: var(--space-sm) 0;
    color: var(--color-text-light);
}

.ai-list li::before {
    content: '';
    position: absolute;
    left: -1.5rem;
    top: 50%;
    transform: translateY(-50%);
    width: 6px;
    height: 6px;
    background: var(--color-accent);
    border-radius: 50%;
}

.ai-focus {
    font-weight: 500;
    color: var(--color-text) !important;
    text-align: center;
}

/* ===================================
   Expertise Section
   =================================== */
.expertise {
    background: var(--color-bg-alt);
}

.expertise-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--space-lg);
    margin-bottom: var(--space-3xl);
}

.expertise-item {
    background: var(--color-bg);
    padding: var(--space-xl);
    border-radius: 12px;
    text-align: center;
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-base);
}

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

.expertise-icon {
    width: 48px;
    height: 48px;
    margin: 0 auto var(--space-md);
    color: var(--color-accent);
}

.expertise-icon svg {
    width: 100%;
    height: 100%;
}

.expertise-item h3 {
    font-family: var(--font-sans);
    font-size: 1rem;
    font-weight: 600;
    margin-bottom: var(--space-sm);
}

.expertise-item p {
    font-size: 0.875rem;
    color: var(--color-text-muted);
}

.platforms {
    text-align: center;
    padding: var(--space-2xl);
    background: var(--color-bg);
    border-radius: 12px;
}

.platforms h3 {
    font-family: var(--font-sans);
    font-weight: 600;
    margin-bottom: var(--space-md);
}

.platforms-list {
    color: var(--color-text-light);
    max-width: var(--container-narrow);
    margin: 0 auto;
}

/* ===================================
   Background Section
   =================================== */
.background {
    background: var(--color-bg);
}

.background-content {
    display: grid;
    grid-template-columns: 1fr;
    gap: var(--space-3xl);
}

.career-narrative {
    max-width: var(--container-narrow);
    margin: 0 auto;
}

.career-narrative h3 {
    margin-bottom: var(--space-lg);
}

.career-narrative p {
    color: var(--color-text-light);
    margin-bottom: var(--space-lg);
}

.career-pattern {
    font-size: 1.125rem;
    color: var(--color-text) !important;
    text-align: center;
    padding: var(--space-xl);
    background: var(--color-bg-alt);
    border-radius: 12px;
    margin-top: var(--space-xl);
}

.education-certs {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--space-2xl);
    max-width: var(--container-narrow);
    margin: 0 auto;
}

.education h3,
.certifications h3 {
    font-family: var(--font-sans);
    font-weight: 600;
    margin-bottom: var(--space-lg);
    padding-bottom: var(--space-sm);
    border-bottom: 2px solid var(--color-accent);
}

.education-item h4 {
    font-family: var(--font-sans);
    font-weight: 600;
    color: var(--color-text);
}

.education-item p {
    color: var(--color-text-light);
    margin-top: var(--space-xs);
}

.education-detail {
    font-size: 0.875rem;
    color: var(--color-text-muted) !important;
}

.education-concentrations {
    margin-top: var(--space-md) !important;
    font-size: 0.9375rem;
}

.cert-list li {
    padding: var(--space-sm) 0;
    color: var(--color-text-light);
    border-bottom: 1px solid var(--color-border-light);
}

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

.cert-note {
    margin-top: var(--space-md);
    font-size: 0.875rem;
    color: var(--color-text-muted);
}

/* ===================================
   Personal Section
   =================================== */
.personal {
    background: var(--color-bg-alt);
}

.personal-content {
    max-width: var(--container-narrow);
    margin: 0 auto;
    text-align: center;
}

.personal-content p {
    color: var(--color-text-light);
    margin-bottom: var(--space-md);
}

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

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

.contact .section-title::after {
    background: var(--color-accent-light);
}

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

.contact-intro {
    font-size: 1.125rem;
    margin-bottom: var(--space-2xl);
    opacity: 0.9;
}

.contact-actions {
    display: flex;
    gap: var(--space-md);
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: var(--space-xl);
}

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

.contact .btn-primary:hover {
    background: var(--color-bg-alt);
    border-color: var(--color-bg-alt);
    color: var(--color-primary);
}

.contact .btn-secondary {
    background: transparent;
    color: white;
    border-color: white;
}

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

.contact-note {
    font-size: 0.875rem;
    opacity: 0.7;
}

/* ===================================
   Footer
   =================================== */
.footer {
    background: var(--color-bg-dark);
    color: white;
    padding: var(--space-xl) 0;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--space-md);
}

.footer-copyright {
    font-size: 0.875rem;
    opacity: 0.7;
}

.footer-social a {
    color: white;
    opacity: 0.7;
    transition: opacity var(--transition-fast);
}

.footer-social a:hover {
    opacity: 1;
}

.footer-social svg {
    width: 24px;
    height: 24px;
}

/* ===================================
   Responsive Design
   =================================== */

/* Tablet */
@media (max-width: 768px) {
    :root {
        --space-4xl: 4rem;
        --space-3xl: 3rem;
    }

    .nav-toggle {
        display: flex;
    }

    .nav-menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: 280px;
        height: 100vh;
        background: var(--color-bg);
        flex-direction: column;
        justify-content: center;
        gap: var(--space-xl);
        padding: var(--space-2xl);
        box-shadow: var(--shadow-xl);
        transition: right var(--transition-base);
    }

    .nav-menu.active {
        right: 0;
    }

    .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 {
        min-height: auto;
        padding: calc(80px + var(--space-3xl)) var(--space-lg) var(--space-3xl);
    }

    .hero-scroll {
        display: none;
    }

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

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

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

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

/* Mobile */
@media (max-width: 480px) {
    :root {
        --space-4xl: 3rem;
        --space-3xl: 2rem;
        --space-2xl: 1.5rem;
    }

    .container {
        padding: 0 var(--space-md);
    }

    .hero-actions {
        flex-direction: column;
        width: 100%;
    }

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

    .contact-actions {
        flex-direction: column;
        width: 100%;
    }

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

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

    .focus-item,
    .expertise-item {
        padding: var(--space-lg);
    }
}

/* Accessibility */
@media (prefers-reduced-motion: reduce) {
    html {
        scroll-behavior: auto;
    }

    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Focus styles */
:focus-visible {
    outline: 2px solid var(--color-accent);
    outline-offset: 2px;
}

/* High contrast mode */
@media (prefers-contrast: high) {
    :root {
        --color-text-light: #2d3748;
        --color-text-muted: #4a5568;
    }
}

/* Print styles */
@media print {
    .navbar,
    .hero-scroll,
    .contact-actions {
        display: none;
    }

    .section {
        padding: var(--space-xl) 0;
        break-inside: avoid;
    }

    .hero {
        min-height: auto;
        padding: var(--space-xl);
    }
}