/* ========================================
   1. CSS CUSTOM PROPERTIES
   ======================================== */

:root {
    --color-bg: #ffffff;
    --color-bg-alt: #f8f8f8;
    --color-text: #333333;
    --color-text-light: #666666;
    --color-text-muted: #999999;
    --color-accent: #2a2a2a;
    --color-overlay: rgba(0, 0, 0, 0.70);
    --color-overlay-text: #ffffff;
    --color-border: #e5e5e5;

    --font-primary: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    --font-size-base: 16px;
    --font-size-small: 14px;
    --font-size-h1: 2.5rem;
    --font-size-h2: 1.75rem;
    --font-size-h3: 1.25rem;
    --line-height: 1.6;

    --space-xs: 0.5rem;
    --space-sm: 1rem;
    --space-md: 2rem;
    --space-lg: 4rem;
    --space-xl: 6rem;

    --max-width: 1000px;
    --nav-height: 72px;
    --grid-gap: 24px;
    --border-radius: 4px;

    --transition-fast: 0.2s ease;
    --transition-med: 0.3s ease;

    --page-padding: clamp(2rem, 5vw, 5rem);
}

/* ========================================
   2. RESET & BASE STYLES
   ======================================== */

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

html {
    font-size: var(--font-size-base);
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-primary);
    color: var(--color-text);
    background-color: var(--color-bg);
    line-height: var(--line-height);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

a {
    color: inherit;
    text-decoration: none;
}

ul {
    list-style: none;
}

/* ========================================
   3. TYPOGRAPHY
   ======================================== */

h1 {
    font-size: var(--font-size-h1);
    font-weight: 600;
    line-height: 1.2;
    letter-spacing: -0.02em;
}

h2 {
    font-size: var(--font-size-h2);
    font-weight: 600;
    line-height: 1.3;
    margin-bottom: var(--space-sm);
}

h3 {
    font-size: var(--font-size-h3);
    font-weight: 500;
    line-height: 1.4;
}

p {
    margin-bottom: var(--space-sm);
    color: var(--color-text-light);
}

/* ========================================
   4. LAYOUT
   ======================================== */

.main-content {
    min-height: calc(100vh - var(--nav-height) - 80px);
    padding-top: var(--space-lg);
}

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

/* ========================================
   5. NAVIGATION
   ======================================== */

.site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background-color: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    height: var(--nav-height);
}

.nav-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--page-padding);
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 100%;
}

.nav-logo {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--color-text);
    text-decoration: none;
    letter-spacing: -0.01em;
}

.nav-links {
    display: flex;
    gap: var(--space-md);
}

.nav-links a {
    text-decoration: none;
    color: var(--color-text-light);
    font-size: var(--font-size-small);
    font-weight: 400;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    transition: color var(--transition-fast);
    position: relative;
}

.nav-links a:hover,
.nav-links a.active {
    color: var(--color-text);
}

.nav-links a.active::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    right: 0;
    height: 1px;
    background-color: var(--color-text);
}

.nav-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
    z-index: 101;
}

.hamburger {
    display: block;
    width: 24px;
    height: 2px;
    background-color: var(--color-text);
    position: relative;
    transition: background-color var(--transition-fast);
}

.hamburger::before,
.hamburger::after {
    content: '';
    position: absolute;
    left: 0;
    width: 24px;
    height: 2px;
    background-color: var(--color-text);
    transition: transform var(--transition-med);
}

.hamburger::before {
    top: -7px;
}

.hamburger::after {
    top: 7px;
}

/* Hamburger open state */
.nav-toggle[aria-expanded="true"] .hamburger {
    background-color: transparent;
}

.nav-toggle[aria-expanded="true"] .hamburger::before {
    top: 0;
    transform: rotate(45deg);
}

.nav-toggle[aria-expanded="true"] .hamburger::after {
    top: 0;
    transform: rotate(-45deg);
}

/* ========================================
   6. HERO SECTION
   ======================================== */

.hero-section {
    text-align: center;
    padding: 0 var(--page-padding) var(--space-lg);
}

.hero-title {
    margin-bottom: var(--space-xs);
}

.hero-subtitle {
    font-size: 1.125rem;
    color: var(--color-text-muted);
    font-weight: 300;
    white-space: nowrap;
    margin: 0 auto;
}

.hero-divider {
    border: none;
    border-top: 1px solid var(--color-border);
    max-width: var(--max-width);
    margin: var(--space-md) auto 0;
}

/* ========================================
   7. PROJECT GRID
   ======================================== */

.projects-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--grid-gap);
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--page-padding) var(--space-xl);
}

.project-card {
    display: block;
    overflow: hidden;
    border-radius: var(--border-radius);
}

.card-image-wrapper {
    position: relative;
    overflow: hidden;
    aspect-ratio: 4 / 3;
    background-color: var(--color-bg-alt);
}

.card-image-wrapper img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition-med);
}

.card-overlay {
    position: absolute;
    inset: 0;
    background: var(--color-overlay);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: var(--space-md);
    opacity: 0;
    transition: opacity var(--transition-med);
}

.card-overlay .card-title {
    color: var(--color-overlay-text);
    font-size: var(--font-size-h3);
    margin-bottom: var(--space-xs);
}

.card-overlay .card-description {
    color: rgba(255, 255, 255, 0.85);
    font-size: var(--font-size-small);
    max-width: 300px;
    margin-bottom: var(--space-sm);
    line-height: 1.5;
}

.card-overlay .card-cta {
    color: var(--color-overlay-text);
    font-size: var(--font-size-small);
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.08em;
}

.project-card:hover .card-image-wrapper img {
    transform: scale(1.05);
}

.project-card:hover .card-overlay {
    opacity: 1;
}

/* ========================================
   8. PROJECT PAGE
   ======================================== */

.project-header {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--page-padding) var(--space-lg);
    text-align: center;
}

.project-tagline {
    font-size: 1.125rem;
    color: var(--color-text-muted);
    font-weight: 300;
    margin-top: var(--space-xs);
}

.project-meta {
    display: flex;
    justify-content: center;
    gap: var(--space-lg);
    margin-top: var(--space-md);
    padding-top: var(--space-md);
    border-top: 1px solid var(--color-border);
}

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

.meta-label {
    display: block;
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--color-text-muted);
    margin-bottom: 4px;
}

.meta-value {
    font-size: var(--font-size-small);
    color: var(--color-text);
    font-weight: 500;
}

.project-section {
    max-width: var(--max-width);
    margin: 0 auto var(--space-lg);
    padding: 0 var(--page-padding);
}

.project-section h2 {
    margin-bottom: var(--space-sm);
}

.project-image {
    max-width: 1000px;
    margin: var(--space-md) auto;
}

.project-image img {
    width: 100%;
    height: auto;
    border-radius: var(--border-radius);
    box-shadow: 0 2px 20px rgba(0, 0, 0, 0.08);
}

.project-image figcaption {
    margin-top: var(--space-sm);
    font-size: var(--font-size-small);
    color: var(--color-text-muted);
    text-align: center;
    font-style: italic;
}

/* Side-by-side images layout */
.images-side-by-side {
    display: flex;
    gap: var(--grid-gap);
    align-items: flex-start;
    margin: var(--space-md) auto;
    max-width: 1000px;
}

.images-side-by-side .project-image {
    margin: 0;
}

.images-side-by-side .project-image.side-small {
    flex: 0 0 40%;
}

.images-side-by-side .project-image.side-large {
    flex: 1;
}

/* Three-column side-by-side layout */
.images-side-by-side-three {
    display: flex;
    gap: var(--grid-gap);
    align-items: flex-start;
    margin: var(--space-md) auto;
    max-width: 1000px;
}

.images-side-by-side-three .project-image {
    flex: 1;
    margin: 0;
}

@media (max-width: 767px) {
    .images-side-by-side,
    .images-side-by-side-three {
        flex-direction: column;
    }

    .images-side-by-side .project-image.side-small {
        flex: none;
    }

    .images-side-by-side-three .project-image {
        flex: none;
    }
}

/* AI Prompt display */
.ai-prompt {
    background-color: var(--color-bg-alt);
    border-left: 3px solid var(--color-accent);
    padding: var(--space-sm) var(--space-md);
    margin: var(--space-sm) 0 var(--space-md);
    border-radius: 0 var(--border-radius) var(--border-radius) 0;
    font-size: var(--font-size-small);
    color: var(--color-text-light);
    font-style: italic;
}

.ai-prompt .prompt-label {
    display: block;
    font-style: normal;
    font-weight: 600;
    font-size: 0.7rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--color-text-muted);
    margin-bottom: 4px;
}

/* Tech stack table */
.tech-table {
    width: 100%;
    border-collapse: collapse;
    margin: var(--space-md) 0;
    font-size: var(--font-size-small);
    color: var(--color-text-light);
}

.tech-table th {
    text-align: left;
    font-weight: 600;
    color: var(--color-text);
    padding: 0.75rem 1rem;
    border-bottom: 2px solid var(--color-border);
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
}

.tech-table td {
    padding: 0.75rem 1rem;
    border-bottom: 1px solid var(--color-border);
    vertical-align: top;
}

.tech-table code {
    font-family: 'SF Mono', 'Fira Code', 'Fira Mono', monospace;
    font-size: 0.8rem;
    background-color: var(--color-bg-alt);
    padding: 0.15rem 0.4rem;
    border-radius: 3px;
}

@media (max-width: 767px) {
    .tech-table {
        font-size: 0.8rem;
    }
    .tech-table th,
    .tech-table td {
        padding: 0.5rem 0.5rem;
    }
}

.project-nav {
    display: flex;
    justify-content: space-between;
    max-width: var(--max-width);
    margin: var(--space-xl) auto var(--space-lg);
    padding: var(--space-md) var(--page-padding);
    border-top: 1px solid var(--color-border);
}

.project-nav-link {
    display: flex;
    flex-direction: column;
    gap: 4px;
    transition: color var(--transition-fast);
}

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

.project-nav-link.next {
    text-align: right;
    margin-left: auto;
}

.nav-direction {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--color-text-muted);
}

.nav-project-name {
    font-size: var(--font-size-small);
    font-weight: 500;
    color: var(--color-text-light);
}

.project-nav-link:hover .nav-project-name {
    color: var(--color-text);
}

/* ========================================
   9. ABOUT PAGE
   ======================================== */

.about-section {
    max-width: 900px;
    margin: 0 auto;
    padding: 0 var(--page-padding) var(--space-xl);
}

.about-section h1 {
    margin-bottom: var(--space-md);
}

.about-layout {
    display: flex;
    gap: var(--space-lg);
    align-items: flex-start;
}

.about-image {
    flex: 0 0 280px;
}

.about-image img {
    width: 100%;
    border-radius: var(--border-radius);
}

.about-image .placeholder-photo {
    width: 100%;
    aspect-ratio: 3 / 4;
    background-color: var(--color-bg-alt);
    border-radius: var(--border-radius);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--color-text-muted);
    font-size: var(--font-size-small);
}

.about-text {
    flex: 1;
}

.about-text h2 {
    margin-top: var(--space-md);
    font-size: var(--font-size-h3);
}

.skills-list {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-xs);
}

.skills-list li {
    background: var(--color-bg-alt);
    padding: 0.4rem 0.8rem;
    border-radius: 2px;
    font-size: var(--font-size-small);
    color: var(--color-text-light);
}

/* ========================================
   10. CONTACT PAGE
   ======================================== */

.contact-section {
    max-width: 600px;
    margin: 0 auto;
    padding: 0 var(--page-padding) var(--space-xl);
    text-align: center;
}

.contact-section h1 {
    margin-bottom: var(--space-sm);
}

.contact-intro {
    margin-bottom: var(--space-lg);
    font-size: 1.125rem;
    white-space: nowrap;
}

.contact-links {
    display: flex;
    flex-direction: column;
    gap: var(--space-sm);
}

.contact-link {
    display: flex;
    align-items: center;
    gap: var(--space-sm);
    padding: var(--space-sm) var(--space-md);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    transition: border-color var(--transition-fast), box-shadow var(--transition-fast);
    text-align: left;
}

.contact-link:hover {
    border-color: var(--color-text-muted);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.06);
}

.contact-icon {
    font-size: 1.5rem;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background-color: var(--color-bg-alt);
    border-radius: 50%;
    flex-shrink: 0;
    font-weight: 600;
}

.contact-label {
    font-weight: 500;
    color: var(--color-text);
    display: block;
    font-size: var(--font-size-small);
}

.contact-value {
    color: var(--color-text-muted);
    font-size: var(--font-size-small);
}

.contact-info {
    display: flex;
    flex-direction: column;
}

/* ========================================
   11. RESUME PAGE
   ======================================== */

.resume-section {
    max-width: 900px;
    margin: 0 auto;
    padding: 0 var(--page-padding) var(--space-xl);
    text-align: center;
}

.resume-section h1 {
    margin-bottom: var(--space-md);
}

.resume-download-btn {
    display: inline-block;
    padding: 0.75rem 2rem;
    background-color: var(--color-text);
    color: var(--color-bg);
    border-radius: var(--border-radius);
    font-size: var(--font-size-small);
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    transition: background-color var(--transition-fast);
    margin-bottom: var(--space-lg);
}

.resume-download-btn:hover {
    background-color: var(--color-text-light);
}

.resume-embed {
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    overflow: hidden;
}

.resume-embed iframe {
    width: 100%;
    height: 800px;
    border: none;
}

.resume-placeholder {
    padding: var(--space-xl);
    background-color: var(--color-bg-alt);
    color: var(--color-text-muted);
    border-radius: var(--border-radius);
}

/* ========================================
   12. FOOTER
   ======================================== */

.site-footer {
    border-top: 1px solid var(--color-border);
    padding: var(--space-md) 0;
}

.footer-container {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--page-padding);
    text-align: center;
}

.footer-container p {
    font-size: var(--font-size-small);
    color: var(--color-text-muted);
}

/* ========================================
   13. RESPONSIVE
   ======================================== */

/* Mobile (default) */
.nav-toggle {
    display: block;
}

.nav-links {
    display: none;
    position: absolute;
    top: var(--nav-height);
    left: 0;
    right: 0;
    background-color: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    flex-direction: column;
    padding: var(--space-sm) var(--page-padding);
}

.nav-links.nav-open {
    display: flex;
}

.nav-links li {
    padding: var(--space-xs) 0;
}

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

.about-layout {
    flex-direction: column;
}

.about-image {
    flex: none;
    max-width: 220px;
}

.project-meta {
    flex-direction: column;
    gap: var(--space-sm);
}

/* Tablet and up */
@media (min-width: 768px) {
    .nav-toggle {
        display: none;
    }

    .nav-links {
        display: flex;
        position: static;
        border-bottom: none;
        flex-direction: row;
        padding: 0;
    }

    .projects-grid {
        grid-template-columns: repeat(3, 1fr);
    }

    .about-layout {
        flex-direction: row;
    }

    .about-image {
        flex: 0 0 280px;
    }

    .project-meta {
        flex-direction: row;
    }
}

/* Desktop */
@media (min-width: 1024px) {
    :root {
        --font-size-h1: 3rem;
    }
}