/* -------------------------------------------------------------
 * GvdDool.github.io - Main stylesheet
 * Design System: Modern Minimalist Editorial
 * Typography: Lora (headings) & Plus Jakarta Sans (body)
 * Colors: Off-whites, warm slates, charcoal and muted earth tones
 * ------------------------------------------------------------- */

/* Custom properties / Tokens */
:root {
    --font-sans: 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    --font-serif: 'Lora', Georgia, serif;
    
    /* Elegant warm-light color palette */
    --color-bg-primary: #FAF9F6;     /* Warm alabaster cream */
    --color-bg-secondary: #F3F1EC;   /* Warm soft stone */
    --color-text-primary: #1F2421;   /* Rich charcoal */
    --color-text-secondary: #5C625E; /* Muted olive-slate */
    --color-accent: #8E7C68;         /* Earth clay gold */
    --color-accent-light: #EBE7E0;   /* Light clay background */
    --color-border: rgba(31, 36, 33, 0.08);
    --color-border-focus: rgba(142, 124, 104, 0.4);
    
    /* Layout */
    --header-height: 80px;
    --container-max-width: 1200px;
    --transition-smooth: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

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

html {
    scroll-behavior: smooth;
    scroll-padding-top: var(--header-height);
}

body {
    font-family: var(--font-sans);
    background-color: var(--color-bg-primary);
    color: var(--color-text-primary);
    line-height: 1.625;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Typography base */
h1, h2, h3, h4 {
    font-family: var(--font-serif);
    font-weight: 500;
    line-height: 1.25;
    color: var(--color-text-primary);
}

p {
    font-weight: 400;
    color: var(--color-text-secondary);
}

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

/* Layout Utilities */
.section-container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 2rem;
}

/* Header & Navigation */
.site-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: var(--header-height);
    background-color: rgba(250, 249, 246, 0.85);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--color-border);
    z-index: 1000;
    display: flex;
    align-items: center;
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    width: 100%;
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 2rem;
}

.site-logo {
    font-family: var(--font-serif);
    font-size: 1.5rem;
    font-weight: 600;
    letter-spacing: -0.02em;
}

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

.site-nav ul {
    display: flex;
    list-style: none;
    align-items: center;
    gap: 2.5rem;
}

.site-nav a {
    font-size: 0.925rem;
    font-weight: 500;
    color: var(--color-text-secondary);
    position: relative;
    padding: 0.25rem 0;
}

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

/* Navigation Line Hover Animation */
.site-nav a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 1px;
    background-color: var(--color-accent);
    transition: var(--transition-smooth);
}

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

.site-nav a.nav-cta {
    background-color: var(--color-text-primary);
    color: var(--color-bg-primary);
    padding: 0.6rem 1.25rem;
    border-radius: 4px;
    transition: var(--transition-smooth);
}

.site-nav a.nav-cta:hover {
    background-color: var(--color-accent);
    color: var(--color-bg-primary);
}

.site-nav a.nav-cta::after {
    display: none;
}

/* Hero Section */
.hero-section {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: var(--header-height);
    background: radial-gradient(circle at 80% 20%, rgba(142, 124, 104, 0.05) 0%, transparent 60%);
}

.hero-container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 2rem;
    width: 100%;
}

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

.hero-tagline {
    display: inline-block;
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 0.15em;
    font-weight: 600;
    color: var(--color-accent);
    margin-bottom: 1.5rem;
}

.hero-title {
    font-size: 3.5rem;
    line-height: 1.15;
    margin-bottom: 1.75rem;
    letter-spacing: -0.015em;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--color-text-secondary);
    margin-bottom: 2.5rem;
    line-height: 1.6;
}

.hero-actions {
    display: flex;
    gap: 1rem;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.875rem 2rem;
    font-size: 0.95rem;
    font-weight: 500;
    border-radius: 4px;
    cursor: pointer;
    border: 1px solid transparent;
}

.btn-primary {
    background-color: var(--color-text-primary);
    color: var(--color-bg-primary);
}

.btn-primary:hover {
    background-color: var(--color-accent);
}

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

.btn-secondary:hover {
    border-color: var(--color-text-primary);
    background-color: rgba(31, 36, 33, 0.02);
}

/* Sections - Editorial layout */
.content-section {
    padding: 7rem 0;
    border-top: 1px solid var(--color-border);
}

.alt-bg {
    background-color: var(--color-bg-secondary);
}

.section-grid {
    display: grid;
    grid-template-columns: 1fr 2.5fr;
    gap: 4rem;
}

.section-header {
    position: sticky;
    top: calc(var(--header-height) + 2rem);
    height: fit-content;
}

.section-label {
    display: block;
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--color-accent);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    margin-bottom: 0.5rem;
}

.section-title {
    font-size: 2rem;
    letter-spacing: -0.01em;
}

.section-body {
    max-width: 750px;
}

.lead-text {
    font-size: 1.25rem;
    line-height: 1.55;
    color: var(--color-text-primary);
    margin-bottom: 1.5rem;
    font-family: var(--font-sans);
    font-weight: 300;
}

.section-body p:not(.lead-text) {
    margin-bottom: 1.5rem;
    font-size: 1.05rem;
}

/* Profile / Skills Section */
.skills-highlight {
    margin-top: 2.5rem;
    padding-top: 2rem;
    border-top: 1px solid var(--color-border);
}

.skills-highlight h3 {
    font-family: var(--font-sans);
    font-size: 1rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-text-primary);
    margin-bottom: 1.25rem;
}

.skills-list {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
    list-style: none;
}

.skills-list li {
    font-size: 0.95rem;
    color: var(--color-text-secondary);
    position: relative;
    padding-left: 1.5rem;
}

.skills-list li::before {
    content: '—';
    position: absolute;
    left: 0;
    color: var(--color-accent);
}

/* Activities Cards Grid */
.activities-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
    margin-top: 2.5rem;
}

.activity-card {
    background-color: var(--color-bg-primary);
    padding: 2.5rem;
    border-radius: 6px;
    border: 1px solid var(--color-border);
    transition: var(--transition-smooth);
}

.alt-bg .activity-card {
    background-color: var(--color-bg-primary);
}

.activity-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 30px rgba(31, 36, 33, 0.04);
    border-color: rgba(142, 124, 104, 0.2);
}

.activity-icon {
    color: var(--color-accent);
    margin-bottom: 1.5rem;
    display: inline-flex;
    padding: 0.75rem;
    border-radius: 4px;
    background-color: var(--color-bg-secondary);
}

.activity-title {
    font-size: 1.35rem;
    margin-bottom: 0.75rem;
    font-family: var(--font-sans);
    font-weight: 600;
}

.activity-desc {
    font-size: 0.975rem;
    color: var(--color-text-secondary);
    line-height: 1.6;
}

.activity-list {
    margin-top: 1rem;
    list-style-type: disc;
    padding-left: 1.25rem;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.activity-list li {
    font-size: 0.95rem;
    color: var(--color-text-secondary);
    line-height: 1.6;
}

.activity-list li strong {
    color: var(--color-text-primary);
}

/* TBC / Placeholder Design */
.tbc-placeholder {
    padding: 4rem 3rem;
    border: 2px dashed var(--color-border);
    border-radius: 8px;
    background-color: rgba(31, 36, 33, 0.01);
    text-align: left;
}

.tbc-badge {
    display: inline-block;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    background-color: var(--color-accent-light);
    color: var(--color-accent);
    padding: 0.25rem 0.75rem;
    border-radius: 20px;
    margin-bottom: 1.5rem;
}

.tbc-placeholder h3 {
    font-family: var(--font-sans);
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
}

.tbc-placeholder p {
    font-size: 0.95rem;
    max-width: 550px;
    color: var(--color-text-secondary);
}

/* Contact Section Links */
.contact-methods {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    margin-top: 3rem;
}

.contact-method-card {
    border: 1px solid var(--color-border);
    padding: 2.5rem;
    border-radius: 6px;
    background-color: var(--color-bg-secondary);
    display: flex;
    flex-direction: column;
    justify-content: space-between;
}

.contact-method-card h3 {
    font-family: var(--font-sans);
    font-weight: 600;
    font-size: 1.15rem;
    margin-bottom: 0.5rem;
}

.contact-method-card p {
    font-size: 0.95rem;
    color: var(--color-text-secondary);
    margin-bottom: 2rem;
}

.contact-link {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-top: 1rem;
    border-top: 1px solid var(--color-border);
    font-weight: 500;
    color: var(--color-text-primary);
    font-size: 0.95rem;
}

.contact-link svg {
    transition: var(--transition-smooth);
    color: var(--color-accent);
}

.contact-method-card:hover .contact-link svg {
    transform: translateX(4px);
}

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

/* Footer styling */
.site-footer {
    padding: 4rem 0;
    background-color: var(--color-text-primary);
    color: #8C9690;
    font-size: 0.9rem;
    border-top: 1px solid rgba(250, 249, 246, 0.05);
}

.footer-container {
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.footer-meta a {
    color: #8C9690;
}

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

/* GitHub Callout Card in Projects */
.project-github-card {
    border: 1px solid var(--color-border);
    padding: 2.5rem;
    border-radius: 6px;
    background-color: var(--color-bg-secondary);
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    margin-bottom: 3rem;
    transition: var(--transition-smooth);
}

.project-github-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 30px rgba(31, 36, 33, 0.04);
    border-color: rgba(142, 124, 104, 0.2);
}

.project-github-card h3 {
    font-family: var(--font-sans);
    font-weight: 600;
    font-size: 1.15rem;
    margin-bottom: 0.5rem;
}

.project-github-card p {
    font-size: 0.95rem;
    color: var(--color-text-secondary);
    margin-bottom: 2rem;
}

.project-github-card:hover .contact-link svg {
    transform: translateX(4px);
}

/* Projects Grid & Cards */
.projects-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    margin-top: 1rem;
}

.project-card {
    background-color: var(--color-bg-primary);
    padding: 2.5rem;
    border-radius: 6px;
    border: 1px solid var(--color-border);
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    transition: var(--transition-smooth);
}

.project-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 30px rgba(31, 36, 33, 0.04);
    border-color: rgba(142, 124, 104, 0.2);
}

.project-meta {
    font-size: 0.85rem;
    color: var(--color-accent);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    font-weight: 600;
    margin-bottom: 0.75rem;
}

.project-title {
    font-size: 1.35rem;
    margin-bottom: 1rem;
    font-family: var(--font-sans);
    font-weight: 600;
}

.project-desc {
    font-size: 0.975rem;
    color: var(--color-text-secondary);
    line-height: 1.6;
    margin-bottom: 1.5rem;
}

.project-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-top: auto;
}

.project-tag {
    font-size: 0.75rem;
    background-color: var(--color-bg-secondary);
    color: var(--color-text-secondary);
    padding: 0.25rem 0.6rem;
    border-radius: 4px;
    font-weight: 500;
}

/* Publications List */
.publications-list {
    display: flex;
    flex-direction: column;
    gap: 1.75rem;
}

.publication-item {
    padding-bottom: 1.75rem;
    border-bottom: 1px solid var(--color-border);
    display: flex;
    flex-direction: column;
}

.publication-item:last-child {
    border-bottom: none;
    padding-bottom: 0;
}

.publication-meta {
    display: flex;
    align-items: center;
    gap: 1rem;
    margin-bottom: 0.5rem;
}

.pub-year {
    font-size: 0.8rem;
    font-weight: 700;
    color: var(--color-accent);
    background-color: var(--color-accent-light);
    padding: 0.15rem 0.5rem;
    border-radius: 4px;
}

.pub-type {
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-text-secondary);
}

.publication-title {
    font-size: 1.15rem;
    font-weight: 600;
    font-family: var(--font-sans);
    color: var(--color-text-primary);
    margin-bottom: 0.35rem;
    line-height: 1.4;
}

.publication-journal {
    font-size: 0.95rem;
    font-style: italic;
    color: var(--color-text-secondary);
}

.publication-authors {
    font-size: 0.9rem;
    color: var(--color-text-secondary);
    margin-top: 0.25rem;
}

.pub-doi {
    margin-top: 0.35rem;
}

.pub-doi a {
    font-size: 0.85rem;
    color: var(--color-accent);
    text-decoration: underline;
    text-underline-offset: 3px;
    display: inline-flex;
    align-items: center;
    gap: 0.35rem;
}

.pub-doi a:hover {
    color: var(--color-text-primary);
}

/* Responsive Design Queries */
@media (max-width: 1024px) {
    .section-grid {
        gap: 3rem;
    }
    .hero-title {
        font-size: 3rem;
    }
}

@media (max-width: 768px) {
    :root {
        --header-height: 70px;
    }
    
    .section-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .section-header {
        position: relative;
        top: 0;
    }
    
    .hero-title {
        font-size: 2.5rem;
    }
    
    .skills-list {
        grid-template-columns: 1fr;
    }
    
    .projects-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    
    .contact-methods {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    
    .site-nav ul {
        gap: 1.5rem;
    }
    
    .site-nav a.nav-cta {
        padding: 0.5rem 1rem;
    }
    
    .content-section {
        padding: 4rem 0;
    }
    
    .footer-container {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .site-nav {
        display: none;
    }
    
    .hero-actions {
        flex-direction: column;
        width: 100%;
    }
    
    .btn {
        width: 100%;
        text-align: center;
    }
}

/* -------------------------------------------------------------
 * Data / Training Tables
 * ------------------------------------------------------------- */
.page-header-section {
    padding: 8rem 0 3rem;
    background-color: var(--color-bg-secondary);
    border-bottom: 1px solid var(--color-border);
}

.table-container {
    overflow-x: auto;
    margin-top: 1.5rem;
    margin-bottom: 3rem;
}

.data-table {
    width: 100%;
    border-collapse: collapse;
    font-size: 0.95rem;
    text-align: left;
}

.data-table th,
.data-table td {
    padding: 1rem 1.25rem;
    border-bottom: 1px solid var(--color-border);
}

.data-table th {
    font-family: var(--font-sans);
    font-weight: 600;
    font-size: 0.825rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--color-accent);
    background-color: var(--color-bg-secondary);
}

.data-table tbody tr {
    transition: var(--transition-smooth);
}

.data-table tbody tr:hover {
    background-color: rgba(142, 124, 104, 0.05);
}

.data-table td a {
    color: var(--color-accent);
    font-weight: 500;
    text-decoration: underline;
    text-underline-offset: 3px;
}

.data-table td a:hover {
    color: var(--color-text-primary);
}