/* CSS Variables for Easy Customisation */
:root {
    /* Color Palette - Earthy, Educational, Sophisticated */
    --primary-sage: #7A9B76;        /* Soft sage green */
    --primary-teal: #5B9AA9;        /* Muted teal */
    --primary-forest: #4A6B5C;      /* Deep forest green */
    --accent-terracotta: #C17767;   /* Warm accent */
    --accent-gold: #B8956A;         /* Subtle gold */
    
    /* Neutrals */
    --off-white: #FDFBF7;           /* Warm off-white */
    --cream: #F5F1E8;               /* Soft cream */
    --stone: #E8E4DA;               /* Light stone */
    --charcoal: #2C3531;            /* Deep charcoal */
    --slate: #545B5A;               /* Medium slate */
    --light-gray: #A8ACA9;          /* Soft grey */
    
    /* Typography */
    --font-serif: 'Baskerville', 'Libre Baskerville', 'Baskerville Old Face', 'Times New Roman', serif;
    --font-sans: 'Baskerville', 'Libre Baskerville', 'Baskerville Old Face', 'Times New Roman', serif;
    
    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 2rem;
    --spacing-lg: 3rem;
    --spacing-xl: 5rem;
    
    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    
    /* Shadows */
    --shadow-subtle: 0 2px 8px rgba(44, 53, 49, 0.08);
    --shadow-medium: 0 4px 16px rgba(44, 53, 49, 0.12);
    --shadow-strong: 0 8px 24px rgba(44, 53, 49, 0.16);
}

/* ===================================
   Base Styles
   =================================== */

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    background-color: var(--off-white);
    color: var(--charcoal);
    line-height: 1.8;
    font-size: 19px;
}

/* ===================================
   Typography
   =================================== */

h1, h2, h3, h4, h5, h6 {
    font-family: var(--font-serif);
    font-weight: 600;
    line-height: 1.3;
    color: var(--charcoal);
    margin-bottom: var(--spacing-sm);
}

h1 {
    font-size: 3.75rem;
    letter-spacing: -0.02em;
}

h2 {
    font-size: 2.75rem;
    letter-spacing: -0.01em;
}

h3 {
    font-size: 2rem;
}

h4 {
    font-size: 1.5rem;
}

p {
    margin-bottom: var(--spacing-sm);
    color: var(--slate);
    font-size: 1.15rem;
    line-height: 1.8;
}

li {
    font-size: 1.15rem;
    line-height: 1.8;
    color: var(--slate);
    margin-bottom: 0.5rem;
}

a {
    color: var(--primary-teal);
    text-decoration: none;
    transition: color 0.3s ease;
}

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

strong {
    font-weight: 600;
    color: var(--charcoal);
}

em {
    font-style: italic;
    color: var(--slate);
}

/* ===================================
   Navigation Bar
   =================================== */

nav {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background-color: rgba(253, 251, 247, 0.95);
    backdrop-filter: blur(10px);
    z-index: 1000;
    border-bottom: 1px solid var(--stone);
    padding: var(--spacing-sm) 0;
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    font-family: var(--font-serif);
    font-size: 1.5rem;
    font-weight: 600;
    color: var(--charcoal);
    letter-spacing: -0.01em;
}

.nav-links {
    display: flex;
    gap: var(--spacing-md);
    list-style: none;
}

.nav-links a {
    font-family: var(--font-sans);
    font-size: 0.95rem;
    font-weight: 500;
    color: var(--slate);
    padding: 0.5rem 0;
    position: relative;
    transition: color 0.3s ease;
}

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--primary-teal);
    transition: width 0.3s ease;
}

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

.nav-links a:hover::after,
.nav-links a.active::after {
    width: 100%;
}

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

/* ===================================
   Layout & Containers
   =================================== */

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

.container-narrow {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

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

.section-hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    text-align: center;
    background: linear-gradient(135deg, var(--primary-sage) 0%, var(--primary-teal) 100%);
    color: var(--off-white);
    padding: var(--spacing-xl) var(--spacing-md);
}

/* ===================================
   Cards & Content Boxes
   =================================== */

.card {
    background: white;
    border-radius: var(--radius-lg);
    padding: var(--spacing-md);
    box-shadow: var(--shadow-subtle);
    transition: transform 0.3s ease, box-shadow 0.3s ease;
}

.card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-medium);
}

.card-title {
    font-family: var(--font-serif);
    font-size: 1.5rem;
    color: var(--charcoal);
    margin-bottom: var(--spacing-sm);
}

.card-text {
    color: var(--slate);
    line-height: 1.7;
}

.content-box {
    background: var(--cream);
    border-left: 4px solid var(--primary-sage);
    padding: var(--spacing-md);
    border-radius: var(--radius-sm);
    margin: var(--spacing-md) 0;
}

/* ===================================
   Buttons
   =================================== */

.btn {
    display: inline-block;
    padding: 0.9rem 2rem;
    font-family: var(--font-sans);
    font-size: 0.95rem;
    font-weight: 500;
    border-radius: var(--radius-md);
    transition: all 0.3s ease;
    cursor: pointer;
    border: none;
    text-align: center;
}

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

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

.btn-secondary {
    background-color: transparent;
    color: var(--primary-teal);
    border: 2px solid var(--primary-teal);
}

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

/* ===================================
   Grid Layouts
   =================================== */

.grid {
    display: grid;
    gap: var(--spacing-md);
}

.grid-2 {
    grid-template-columns: repeat(2, 1fr);
}

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

/* ===================================
   Visualisation Containers
   =================================== */

.viz-container {
    background: white;
    padding: var(--spacing-md);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-subtle);
    margin: var(--spacing-md) 0;
}

.viz-title {
    font-family: var(--font-serif);
    font-size: 1.8rem;
    color: var(--charcoal);
    margin-bottom: var(--spacing-sm);
    text-align: center;
}

.viz-description {
    color: var(--slate);
    text-align: center;
    margin-bottom: var(--spacing-md);
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

/* Centre all visualisations */
.vis-center {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 100%;
    margin: var(--spacing-lg) auto;
}

.vis-center > div {
    display: flex;
    justify-content: center;
}

/* Smooth transitions for map switching */
.map-section {
    transition: opacity 0.3s ease-in-out;
}

/* Chart notes and captions */
.chart-note {
    font-size: 1rem;
    font-style: italic;
    color: var(--slate);
    text-align: center;
    margin-top: var(--spacing-sm);
    max-width: 900px;
    margin-left: auto;
    margin-right: auto;
    line-height: 1.6;
}

.transition-text {
    text-align: center;
    font-size: 1.35rem;
    font-style: italic;
    color: var(--primary-forest);
    margin: var(--spacing-xl) auto;
    max-width: 800px;
    line-height: 1.7;
}

/* ===================================
   Footer
   =================================== */

footer {
    background-color: var(--charcoal);
    color: var(--cream);
    padding: var(--spacing-lg) 0;
    text-align: center;
    margin-top: var(--spacing-xl);
}

footer a {
    color: var(--primary-sage);
}

footer a:hover {
    color: var(--accent-gold);
}

/* ===================================
   Utility Classes
   =================================== */

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

.text-left {
    text-align: left;
}

.mt-sm { margin-top: var(--spacing-sm); }
.mt-md { margin-top: var(--spacing-md); }
.mt-lg { margin-top: var(--spacing-lg); }
.mt-xl { margin-top: var(--spacing-xl); }

.mb-sm { margin-bottom: var(--spacing-sm); }
.mb-md { margin-bottom: var(--spacing-md); }
.mb-lg { margin-bottom: var(--spacing-lg); }
.mb-xl { margin-bottom: var(--spacing-xl); }

.color-sage { color: var(--primary-sage); }
.color-teal { color: var(--primary-teal); }
.color-forest { color: var(--primary-forest); }

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

@media (max-width: 768px) {
    body {
        font-size: 17px;
    }
    
    h1 { font-size: 2.75rem; }
    h2 { font-size: 2.25rem; }
    h3 { font-size: 1.75rem; }
    
    p, li {
        font-size: 1.05rem;
    }
    
    .nav-links {
        gap: var(--spacing-sm);
    }
    
    .grid-2,
    .grid-3 {
        grid-template-columns: 1fr;
    }
    
    .section {
        padding: var(--spacing-md) 0;
    }
}

@media (max-width: 480px) {
    body {
        font-size: 16px;
    }
    
    h1 { font-size: 2.25rem; }
    h2 { font-size: 1.85rem; }
    h3 { font-size: 1.5rem; }
    
    p, li {
        font-size: 1rem;
    }
    
    .nav-container {
        flex-direction: column;
        gap: var(--spacing-sm);
    }
}
/* ===================================
   Portfolio Page Specific Styles
   =================================== */

.portfolio-page figure {
    margin: var(--spacing-md) auto;
    display: flex;
    justify-content: center;
    width: 100%;
    max-width: 1000px;
}

.portfolio-page figure > div {
    margin: 0 auto;
}

.portfolio-page .vega-embed {
    margin: 0 auto;
    display: flex;
    justify-content: center;
}

.portfolio-page .info-box {
    margin-left: auto !important;
    margin-right: auto !important;
    display: block;
}

/* ===================================
   Disclosure Section
   =================================== */

.ai-disclosure {
    max-width: 600px;
    margin: 0 auto 20px auto;
    font-size: 0.9rem;
}

.ai-disclosure summary {
    cursor: pointer;
    color: var(--primary-sage);
    opacity: 0.7;
    padding: 8px;
    border-radius: 4px;
    transition: opacity 0.3s ease;
}

.ai-disclosure summary:hover {
    opacity: 1;
}

.ai-disclosure p {
    margin: 10px 0 0 0;
    padding: 12px;
    background-color: #8DA097;
    border-radius: 4px;
    line-height: 1.5;
    font-size: 0.85rem;  
}