/* ==========================================================================
   Senior Engineer Portfolio - Refined Editorial Style
   ========================================================================== */

/* --------------------------------------------------------------------------
   CSS Custom Properties
   -------------------------------------------------------------------------- */
:root {
    /* Colors */
    --color-primary: #1a1a2e;
    --color-background: #fafaf8;
    --color-accent: #b8860b;
    --color-accent-hover: #9a7209;
    --color-secondary: #64748b;
    --color-border: #e2e2e0;
    --color-surface: #ffffff;
    --color-muted: #94a3b8;
    
    /* Typography */
    --font-display: 'Playfair Display', Georgia, serif;
    --font-body: 'Source Sans 3', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: 'JetBrains Mono', Consolas, monospace;
    
    /* Spacing (8px base unit) */
    --space-xs: 0.5rem;   /* 8px */
    --space-sm: 1rem;     /* 16px */
    --space-md: 1.5rem;   /* 24px */
    --space-lg: 2rem;     /* 32px */
    --space-xl: 3rem;     /* 48px */
    --space-2xl: 4rem;    /* 64px */
    --space-3xl: 6rem;    /* 96px */
    --space-4xl: 8rem;    /* 128px */
    
    /* Layout */
    --max-width: 1200px;
    --content-width: 800px;
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
    --transition-slow: 400ms ease;
}

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

html {
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-body);
    font-size: 1.0625rem;
    font-weight: 400;
    line-height: 1.7;
    color: var(--color-primary);
    background-color: var(--color-background);
}

::selection {
    background-color: var(--color-accent);
    color: var(--color-surface);
}

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-accent-hover);
}

a:focus-visible {
    outline: 2px solid var(--color-accent);
    outline-offset: 2px;
}

ul, ol {
    list-style: none;
}

strong {
    font-weight: 600;
}

/* --------------------------------------------------------------------------
   Typography
   -------------------------------------------------------------------------- */
h1, h2, h3, h4 {
    font-family: var(--font-display);
    font-weight: 500;
    line-height: 1.2;
    letter-spacing: -0.02em;
}

h1 {
    font-size: clamp(3rem, 8vw, 6rem);
    font-weight: 400;
}

h2 {
    font-size: clamp(2rem, 4vw, 2.75rem);
}

h3 {
    font-size: 1.375rem;
    font-weight: 600;
}

h4 {
    font-size: 1rem;
    font-weight: 600;
    font-family: var(--font-body);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--color-secondary);
}

p {
    margin-bottom: 1em;
}

p:last-child {
    margin-bottom: 0;
}

/* --------------------------------------------------------------------------
   Navigation
   -------------------------------------------------------------------------- */
.nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background-color: rgba(250, 250, 248, 0.95);
    backdrop-filter: blur(10px);
    border-bottom: 1px solid var(--color-border);
}

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

.nav-logo {
    font-family: var(--font-display);
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--color-primary);
    letter-spacing: -0.02em;
}

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

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

.nav-links a {
    font-size: 0.9375rem;
    font-weight: 500;
    color: var(--color-secondary);
    transition: color var(--transition-fast);
}

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

.nav-cta {
    padding: var(--space-xs) var(--space-sm);
    border: 1px solid var(--color-primary);
    color: var(--color-primary) !important;
    transition: all var(--transition-fast);
}

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

/* Mobile navigation */
@media (max-width: 768px) {
    .nav-links {
        display: none;
    }
}

/* --------------------------------------------------------------------------
   Hero Section
   -------------------------------------------------------------------------- */
.hero {
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    padding: var(--space-4xl) var(--space-lg) var(--space-2xl);
    position: relative;
}

.hero-content {
    max-width: var(--max-width);
    margin: 0 auto;
    width: 100%;
}

.hero-eyebrow {
    font-family: var(--font-mono);
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--color-accent);
    text-transform: uppercase;
    letter-spacing: 0.15em;
    margin-bottom: var(--space-sm);
}

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

.hero-tagline {
    font-size: clamp(1.125rem, 2vw, 1.375rem);
    color: var(--color-secondary);
    max-width: 650px;
    margin-bottom: var(--space-xl);
    line-height: 1.6;
}

.hero-stats {
    display: flex;
    gap: var(--space-xl);
    padding-top: var(--space-lg);
    border-top: 1px solid var(--color-border);
}

.stat {
    display: flex;
    flex-direction: column;
    gap: 0.25rem;
}

.stat-number {
    font-family: var(--font-display);
    font-size: 2rem;
    font-weight: 500;
    color: var(--color-primary);
    letter-spacing: -0.02em;
}

.stat-label {
    font-size: 0.875rem;
    color: var(--color-secondary);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

/* Scroll indicator */
.scroll-indicator {
    position: absolute;
    bottom: var(--space-lg);
    left: var(--space-lg);
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    color: var(--color-muted);
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.15em;
}

.scroll-line {
    width: 60px;
    height: 1px;
    background-color: var(--color-muted);
    position: relative;
    overflow: hidden;
}

.scroll-line::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: var(--color-accent);
    animation: scrollLine 2s ease-in-out infinite;
}

@keyframes scrollLine {
    0% { transform: translateX(-100%); }
    50% { transform: translateX(0); }
    100% { transform: translateX(100%); }
}

/* --------------------------------------------------------------------------
   Section Styles (Shared)
   -------------------------------------------------------------------------- */
.section {
    padding: var(--space-4xl) var(--space-lg);
}

.section-container {
    max-width: var(--max-width);
    margin: 0 auto;
}

.section-header {
    display: flex;
    align-items: baseline;
    gap: var(--space-md);
    margin-bottom: var(--space-2xl);
    padding-bottom: var(--space-sm);
    border-bottom: 1px solid var(--color-border);
}

.section-number {
    font-family: var(--font-mono);
    font-size: 0.875rem;
    color: var(--color-accent);
    letter-spacing: 0.05em;
}

.section-title {
    color: var(--color-primary);
}

/* --------------------------------------------------------------------------
   About Section
   -------------------------------------------------------------------------- */
.about-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: var(--space-3xl);
}

.about-lead {
    font-size: 1.25rem;
    font-weight: 400;
    color: var(--color-primary);
    line-height: 1.6;
    margin-bottom: var(--space-md);
}

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

.about-text p:not(.about-lead) {
    font-size: 1rem;
}

.about-details {
    display: flex;
    flex-direction: column;
    gap: var(--space-lg);
    padding-left: var(--space-lg);
    border-left: 1px solid var(--color-border);
}

.detail-block h3 {
    font-family: var(--font-body);
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--color-muted);
    margin-bottom: var(--space-xs);
}

.detail-block p {
    font-size: 1rem;
    color: var(--color-primary);
    line-height: 1.5;
}

@media (max-width: 768px) {
    .about-content {
        grid-template-columns: 1fr;
        gap: var(--space-xl);
    }
    
    .about-details {
        flex-direction: row;
        flex-wrap: wrap;
        padding-left: 0;
        padding-top: var(--space-lg);
        border-left: none;
        border-top: 1px solid var(--color-border);
    }
    
    .detail-block {
        flex: 1;
        min-width: 150px;
    }
}

/* --------------------------------------------------------------------------
   Projects Section
   -------------------------------------------------------------------------- */
.projects {
    background-color: var(--color-surface);
}

.projects-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--space-lg);
}

.project-card {
    padding: var(--space-lg);
    background-color: var(--color-background);
    border: 1px solid var(--color-border);
    transition: all var(--transition-base);
    display: flex;
    flex-direction: column;
}

.project-card:hover {
    border-color: var(--color-accent);
    transform: translateY(-4px);
    box-shadow: 0 12px 40px rgba(26, 26, 46, 0.08);
}

.project-header {
    margin-bottom: var(--space-sm);
}

.project-category {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    font-weight: 500;
    color: var(--color-accent);
    text-transform: uppercase;
    letter-spacing: 0.1em;
}

.project-title {
    font-size: 1.5rem;
    margin-top: var(--space-xs);
    color: var(--color-primary);
}

.project-description {
    color: var(--color-secondary);
    font-size: 0.9375rem;
    line-height: 1.6;
    margin-bottom: var(--space-md);
}

.project-impact {
    background-color: var(--color-surface);
    padding: var(--space-sm);
    margin-bottom: var(--space-md);
    border-left: 3px solid var(--color-accent);
}

.project-impact h4 {
    font-size: 0.6875rem;
    margin-bottom: var(--space-xs);
}

.project-impact ul {
    display: flex;
    flex-direction: column;
    gap: 0.375rem;
}

.project-impact li {
    font-size: 0.875rem;
    color: var(--color-primary);
    position: relative;
    padding-left: var(--space-sm);
}

.project-impact li::before {
    content: '→';
    position: absolute;
    left: 0;
    color: var(--color-accent);
}

.project-tech {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-bottom: var(--space-md);
    margin-top: auto;
}

.tech-tag {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    padding: 0.25rem 0.625rem;
    background-color: var(--color-surface);
    border: 1px solid var(--color-border);
    color: var(--color-secondary);
}

.project-links {
    display: flex;
    gap: var(--space-md);
    padding-top: var(--space-sm);
    border-top: 1px solid var(--color-border);
}

.project-link {
    font-size: 0.875rem;
    font-weight: 500;
}

@media (max-width: 900px) {
    .projects-grid {
        grid-template-columns: 1fr;
    }
}

/* --------------------------------------------------------------------------
   Skills Section
   -------------------------------------------------------------------------- */
.skills-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-xl) var(--space-lg);
}

.skill-category h3 {
    font-family: var(--font-body);
    font-size: 0.8125rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--color-accent);
    margin-bottom: var(--space-sm);
    padding-bottom: var(--space-xs);
    border-bottom: 1px solid var(--color-border);
}

.skill-list {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.skill-list li {
    font-size: 0.9375rem;
    color: var(--color-secondary);
    transition: color var(--transition-fast);
}

.skill-list li:hover {
    color: var(--color-primary);
}

@media (max-width: 900px) {
    .skills-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 600px) {
    .skills-grid {
        grid-template-columns: 1fr;
    }
}

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

.timeline {
    display: flex;
    flex-direction: column;
    gap: var(--space-xl);
    position: relative;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 7px;
    top: 0;
    bottom: 0;
    width: 1px;
    background-color: var(--color-border);
}

.timeline-item {
    display: grid;
    grid-template-columns: auto 1fr;
    gap: var(--space-lg);
    position: relative;
}

.timeline-marker {
    width: 15px;
    height: 15px;
    border-radius: 50%;
    border: 3px solid var(--color-accent);
    background-color: var(--color-surface);
    position: relative;
    z-index: 1;
    flex-shrink: 0;
}

.timeline-content {
    padding-bottom: var(--space-lg);
    border-bottom: 1px solid var(--color-border);
}

.timeline-item:last-child .timeline-content {
    border-bottom: none;
}

.timeline-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    gap: var(--space-md);
    margin-bottom: var(--space-sm);
}

.timeline-company {
    font-size: 1.375rem;
    color: var(--color-primary);
}

.timeline-role {
    font-size: 1rem;
    color: var(--color-accent);
    font-weight: 500;
    margin-top: 0.25rem;
}

.timeline-date {
    font-family: var(--font-mono);
    font-size: 0.8125rem;
    color: var(--color-muted);
    white-space: nowrap;
}

.timeline-description {
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.timeline-description li {
    font-size: 0.9375rem;
    color: var(--color-secondary);
    line-height: 1.6;
    position: relative;
    padding-left: var(--space-sm);
}

.timeline-description li::before {
    content: '—';
    position: absolute;
    left: 0;
    color: var(--color-muted);
}

@media (max-width: 600px) {
    .timeline::before {
        display: none;
    }
    
    .timeline-item {
        grid-template-columns: 1fr;
    }
    
    .timeline-marker {
        display: none;
    }
    
    .timeline-header {
        flex-direction: column;
        gap: 0.25rem;
    }
    
    .timeline-date {
        order: -1;
    }
}

/* --------------------------------------------------------------------------
   Contact Section
   -------------------------------------------------------------------------- */
.contact-content {
    max-width: var(--content-width);
}

.contact-lead {
    font-size: 1.25rem;
    color: var(--color-secondary);
    margin-bottom: var(--space-xl);
}

.contact-methods {
    margin-bottom: var(--space-lg);
}

.contact-email {
    font-family: var(--font-display);
    font-size: clamp(1.5rem, 3vw, 2.25rem);
    font-weight: 400;
    color: var(--color-primary);
    display: inline-block;
    margin-bottom: var(--space-md);
    position: relative;
}

.contact-email::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 2px;
    background-color: var(--color-accent);
    transform: scaleX(0);
    transform-origin: right;
    transition: transform var(--transition-base);
}

.contact-email:hover::after {
    transform: scaleX(1);
    transform-origin: left;
}

.contact-links {
    display: flex;
    gap: var(--space-lg);
    flex-wrap: wrap;
}

.contact-link {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.9375rem;
    color: var(--color-secondary);
    transition: color var(--transition-fast);
}

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

.contact-link svg {
    width: 20px;
    height: 20px;
}

.contact-availability {
    font-size: 0.9375rem;
    color: var(--color-muted);
    font-style: italic;
    padding-top: var(--space-lg);
    border-top: 1px solid var(--color-border);
}

/* --------------------------------------------------------------------------
   Footer
   -------------------------------------------------------------------------- */
.footer {
    padding: var(--space-xl) var(--space-lg);
    border-top: 1px solid var(--color-border);
}

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

.footer-copyright {
    font-size: 0.875rem;
    color: var(--color-secondary);
}

.footer-note {
    font-size: 0.8125rem;
    color: var(--color-muted);
}

@media (max-width: 600px) {
    .footer-container {
        flex-direction: column;
        gap: var(--space-xs);
        text-align: center;
    }
}

/* --------------------------------------------------------------------------
   Animations & Effects
   -------------------------------------------------------------------------- */

/* Fade in animation for sections */
.section {
    animation: fadeIn 0.6s ease-out;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Hover effects */
.project-card,
.timeline-item,
.skill-category {
    transition: transform var(--transition-base);
}

/* Smooth focus for accessibility */
*:focus-visible {
    outline: 2px solid var(--color-accent);
    outline-offset: 3px;
}

/* --------------------------------------------------------------------------
   Print Styles
   -------------------------------------------------------------------------- */
@media print {
    .nav,
    .scroll-indicator,
    .project-links,
    .contact-links {
        display: none;
    }
    
    .hero {
        min-height: auto;
        padding-top: var(--space-lg);
    }
    
    .section {
        padding: var(--space-lg) 0;
        break-inside: avoid;
    }
    
    body {
        font-size: 11pt;
    }
    
    a {
        color: inherit;
    }
}

/* --------------------------------------------------------------------------
   Utility Classes
   -------------------------------------------------------------------------- */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}