/* ==========================================================================
   1. Typography & Global Scaling Updates
   ========================================================================== */
/* Core Brand Color Tokens */
:root,
:root[data-theme="dark"] {
    --bg-dark: #020617;
    --bg-radial: radial-gradient(circle at 50% 0%, #0f172a 0%, #020617 80%);
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --accent: #3b82f6;
    --accent-glow: rgba(59, 130, 246, 0.25);
    --card-bg: rgba(15, 23, 42, 0.55);
    --border-color: rgba(255, 255, 255, 0.08);
    --border-hover: rgba(255, 255, 255, 0.15);
    --header-bg: rgba(2, 6, 23, 0.5);
    --commentary-bg: rgba(2, 6, 23, 0.3);
    --commentary-border: rgba(255, 255, 255, 0.05);
    --math-bg: rgba(2, 6, 23, 0.4);
    --scrollbar-thumb: rgba(255, 255, 255, 0.1);
    --scrollbar-thumb-hover: rgba(255, 255, 255, 0.2);
    --hero-title-gradient: linear-gradient(180deg, #ffffff 40%, #94a3b8 100%);
    --metric-num-gradient: linear-gradient(135deg, #ffffff 50%, var(--accent) 100%);
    --shadow-premium: 0 4px 30px rgba(0, 0, 0, 0.3);
    --tab-header-bg: rgba(2, 6, 23, 0.4);
    --tab-btn-hover-bg: rgba(255, 255, 255, 0.02);
    --tab-btn-active-bg: rgba(255, 255, 255, 0.03);

    --font-main: 'Inter', system-ui, -apple-system, sans-serif;
    --font-mono: 'JetBrains Mono', monospace;
    --max-width: 1200px;

    /* Categorical Colors matching Python */
    --color-romance: #EA4335;
    --color-slavic: #4285F4;
    --color-dravidian: #34A853;
    --color-celtic: #FBBC05;
    --color-nordic: #12B5CB;
    --color-austronesian: #9334E6;
    --color-eastasian: #FC5C9C;
    --color-afroasiatic: #FF6D00;
    --color-african: #795548;
    --color-americas: #607D8B;
}

:root[data-theme="light"] {
    --bg-dark: #f8fafc;
    --bg-radial: radial-gradient(circle at 50% 0%, #f1f5f9 0%, #e2e8f0 100%);
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --accent: #2563eb;
    --accent-glow: rgba(37, 99, 235, 0.12);
    --card-bg: rgba(255, 255, 255, 0.85);
    --border-color: rgba(15, 23, 42, 0.08);
    --border-hover: rgba(15, 23, 42, 0.15);
    --header-bg: rgba(248, 250, 252, 0.85);
    --commentary-bg: rgba(15, 23, 42, 0.02);
    --commentary-border: rgba(15, 23, 42, 0.04);
    --math-bg: rgba(15, 23, 42, 0.03);
    --scrollbar-thumb: rgba(0, 0, 0, 0.15);
    --scrollbar-thumb-hover: rgba(0, 0, 0, 0.25);
    --hero-title-gradient: linear-gradient(180deg, #0f172a 40%, #475569 100%);
    --metric-num-gradient: linear-gradient(135deg, #0f172a 50%, var(--accent) 100%);
    --shadow-premium: 0 4px 20px rgba(15, 23, 42, 0.05);
    --tab-header-bg: rgba(15, 23, 42, 0.02);
    --tab-btn-hover-bg: rgba(15, 23, 42, 0.02);
    --tab-btn-active-bg: rgba(37, 99, 235, 0.08);
}

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

body {
    background-color: var(--bg-dark);
    background-image: var(--bg-radial);
    background-attachment: fixed;
    color: var(--text-primary);
    font-family: var(--font-main);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

/* Scrollbar Styling */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background: var(--bg-dark);
}

::-webkit-scrollbar-thumb {
    background: var(--scrollbar-thumb);
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--scrollbar-thumb-hover);
}

/* Layout Container */
.container {
    width: 100%;
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 1.5rem; /* Balanced padding across viewports */
}

/* Translucent Navbar */
.site-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    padding: 0.8rem 0; /* Slimmer navbar for a compact, engineered look */
    z-index: 100;
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
    background-color: var(--header-bg);
    transition: all 0.3s ease;
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo-wrapper {
    display: inline-flex;
    align-items: center;
    gap: 0.75rem;
    text-decoration: none;
    cursor: pointer;
}

.swiss-flag-animated svg {
    width: 18px;
    height: 18px;
    display: block;
    filter: drop-shadow(0 0 2px rgba(218, 41, 28, 0.3));
    animation: flagPulse 3s infinite ease-in-out;
}

.brand-text {
    font-size: 1.rem;
    font-weight: 700;
    letter-spacing: 0.03em;
    background: linear-gradient(135deg, var(--text-primary) 0%, var(--text-secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.nav-back {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.8rem;
    font-weight: 600;
    letter-spacing: 0.1em;
    text-transform: uppercase;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: color 0.3s ease, transform 0.3s ease;
}

.nav-back:hover {
    color: var(--text-primary);
    transform: translateX(-3px);
}

@keyframes flagPulse {

    0%,
    100% {
        filter: drop-shadow(0 0 0 rgba(218, 41, 28, 0));
        transform: scale(1);
    }

    50% {
        filter: drop-shadow(0 0 8px rgba(218, 41, 28, 0.5));
        transform: scale(1.05);
    }
}

/* Main Content */
main {
    margin-top: 6.5rem;
    padding-bottom: 5rem;
}

/* ==========================================================================
   3. Hero Section (Controlled Scale)
   ========================================================================== */
/* Hero Banner section */
.hero-banner {
    text-align: left;
    padding: 3rem 0 1.5rem 0;
    margin-bottom: 1.5rem;
    position: relative;
}

.hero-pre {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.2em;
    color: var(--accent);
    margin-bottom: 0.5rem;
    font-weight: 600;
    text-shadow: 0 0 10px rgba(59, 130, 246, 0.4);
}

.hero-title {
    font-size: clamp(1.6rem, 4vw, 2.4rem);
    font-weight: 800;
    line-height: 1.2;
    letter-spacing: -0.02em;
    background: var(--hero-title-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 1rem;
}

.hero-desc {
    font-size: clamp(0.95rem, 2vw, 1rem);
    color: var(--text-secondary);
    max-width: 720px;
    margin: 0;
    line-height: 1.5;
}

/* Key Metrics Grid */
.metrics-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 1rem;
    margin-bottom: 2.5rem;
}

.metric-card {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    padding: 1.25rem;
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
    transition: border-color 0.2s, transform 0.3s;
}

.metric-card:hover {
    border-color: var(--border-hover);
    transform: translateY(-2px);
}

.metric-num {
    font-size: 1.8rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    font-family: var(--font-mono);
    background: var(--metric-num-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.metric-label {
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-secondary);
    font-weight: 600;
}

.metric-detail {
    font-size: 0.75rem;
    color: rgba(148, 163, 184, 0.6);
    line-height: 1.4;
}

/* Dashboard Visual Grid */
.visual-row {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2rem;
    margin-bottom: 3rem;
}

.visual-row-2col {
    display: grid;
    grid-template-columns: 1.4fr 1fr;
    gap: 2rem;
    margin-bottom: 3rem;
}

@media (max-width: 1024px) {
    .visual-row-2col {
        grid-template-columns: 1fr;
    }

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

@media (max-width: 768px) {
    .metrics-grid {
        grid-template-columns: 1fr;
    }

    .cart-container {
        min-width: 300px;
        aspect-ratio: 4 / 3;
    }

    .pie-charts-container {
        flex-direction: column;
        gap: 1rem;
    }

    .donut-card {
        height: 220px;
    }
}

/* ==========================================================================
   5. Chart Containers & Card Refinement
   ========================================================================== */
.dashboard-card {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    padding: 1.5rem;
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    box-shadow: var(--shadow-premium);
    display: flex;
    flex-direction: column;
    transition: border-color 0.3s;
}

.dashboard-card:hover {
    border-color: var(--border-hover);
}

.card-header {
    margin-bottom: 1.5rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 1rem;
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
}

.card-title-group h2 {
    font-size: 1.35rem;
    font-weight: 700;
    letter-spacing: -0.02em;
    color: var(--text-primary);
    margin-bottom: 0.35rem;
}

.card-title-group p {
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.4;
}

.card-badge {
    background-color: rgba(59, 130, 246, 0.1);
    border: 1px solid rgba(59, 130, 246, 0.25);
    color: var(--accent);
    font-family: var(--font-mono);
    font-size: 0.7rem;
    font-weight: 700;
    text-transform: uppercase;
    padding: 0.35rem 0.75rem;
    border-radius: 99px;
    letter-spacing: 0.05em;
}

/* Chart container anchors */
.chart-container {
    width: 100%;
    height: auto;
    min-height: 250px;
    position: relative;
    background-color: rgba(2, 6, 23, 0.2);
    aspect-ratio: 16 / 10;
    border-radius: 12px;
    overflow: hidden;
    /* Removed flex centering to avoid Plotly offset */
    display: block;
}

.pie-charts-container {
    display: flex;
    flex-direction: row;
    gap: 1rem;
    height: 100%;
    justify-content: space-between;
}

.donut-card {
    flex: 1;
    background-color: rgba(2, 6, 23, 0.25);
    border: 1px solid rgba(255, 255, 255, 0.03);
    border-radius: 10px;
    padding: 1rem;
    height: 250px;
    position: relative;
}

.donut-title {
    font-size: 0.85rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-secondary);
    margin-bottom: 0.5rem;
    text-align: center;
    border-bottom: 1px solid rgba(255, 255, 255, 0.03);
    padding-bottom: 0.25rem;
}

/* Geolinguistic Redlining conceptual zones legends */
.scatter-legend {
    display: flex;
    gap: 1.5rem;
    margin-top: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.legend-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.78rem;
    color: var(--text-secondary);
    background: rgba(255, 255, 255, 0.02);
    border: 1px solid rgba(255, 255, 255, 0.04);
    padding: 0.4rem 0.8rem;
    border-radius: 6px;
}

.legend-color {
    width: 12px;
    height: 12px;
    border-radius: 3px;
}

.legend-color.green-zone {
    background-color: rgba(46, 204, 113, 0.25);
    border: 1.5px dashed #27AE60;
}

.legend-color.red-zone {
    background-color: rgba(231, 76, 60, 0.25);
    border: 1.5px dashed #C0392B;
}

/* Commentary Blocks */
.commentary-box {
    margin-top: 1.5rem;
    background-color: rgba(255, 255, 255, 0.02);
    border-left: 3px solid var(--accent);
    border-radius: 0 8px 8px 0;
    padding: 1.25rem;
    font-size: 0.9rem;
    line-height: 1.6;
    color: var(--text-secondary);
}

.commentary-box strong {
    color: var(--text-primary);
}

.commentary-box.warning-theme {
    border-left-color: #EA4335;
}

/* ==========================================================================
   6. Document & Editorial Content Polish
   ========================================================================== */

/* Storytelling section */
.story-section {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    padding: 2rem;
    margin-bottom: 2.5rem;
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
}

.story-section h2 {
    font-size: 1.4rem;
    font-weight: 700;
    letter-spacing: -0.03em;
    margin-bottom: 1.5rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.75rem;
}

.story-grid {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 3rem;
}

@media (max-width: 1024px) {
    .story-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
    }

    .story-section {
        padding: 2rem;
    }

    .tabs-header {
        flex-direction: column; /* Stack tabs cleanly on small phone screens */
    }
    
    .tab-btn {
        width: 100%;
        text-align: left;
        padding: 0.8rem 1.2rem;
        border-bottom: 1px solid var(--border-color);
    }
    
    .tab-btn.active::after {
        left: 0;
        bottom: 0;
        width: 3px;
        height: 100%; /* Transforms bottom underline into an intentional left anchor bar */
    }    
}

.story-text p {
    font-size: 0.92rem;
    color: var(--text-secondary);
    line-height: 1.6;
    margin-bottom: 1.1rem;
}

.story-text em {
    color: var(--text-primary);
    font-style: italic;
}

.story-text strong {
    color: var(--text-primary);
    font-weight: 600;
}

.story-card {
    background-color: var(--commentary-bg);
    border: 1px solid var(--commentary-border);
    border-radius: 12px;
    padding: 1.75rem;
    display: flex;
    flex-direction: column;
    gap: 1.2rem;
    height: fit-content;
}

.story-card h3 {
    font-size: 1.1rem;
    font-weight: 600;
    color: var(--text-primary);
    border-bottom: 1px solid var(--commentary-border);
    padding-bottom: 0.5rem;
}

.paradox-item {
    display: flex;
    flex-direction: column;
    gap: 0.35rem;
}

.paradox-item h4 {
    font-size: 0.85rem;
    color: var(--accent);
    text-transform: uppercase;
    letter-spacing: 0.05em;
    font-family: var(--font-mono);
}

.paradox-item p {
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

/* Academic Reference Tabs */
.tabs-container {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    overflow: hidden;
    margin-bottom: 3rem;
    backdrop-filter: blur(16px);
}

.tabs-header {
    display: flex;
    background-color: var(--tab-header-bg);
    border-bottom: 1px solid var(--border-color);
}

.tab-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    font-family: var(--font-main);
    font-size: 0.85rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    padding: 1.2rem 2rem;
    cursor: pointer;
    transition: all 0.3s ease;
    position: relative;
}

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

.tab-btn.active {
    color: var(--accent);
    background-color: var(--tab-btn-active-bg);
}

.tab-btn.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    height: 2px;
    background-color: var(--accent);
    box-shadow: 0 0 10px var(--accent);
}

.tab-content {
    padding: 2.5rem;
    display: none;
}

.tab-content.active {
    display: block;
    animation: fadeIn 0.4s ease forwards;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(8px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.abstract-text {
    font-size: 1rem;
    color: var(--text-secondary);
    line-height: 1.8;
    margin-bottom: 1.5rem;
    text-align: justify;
}

.abstract-keywords {
    font-size: 0.85rem;
    font-family: var(--font-mono);
    color: rgba(148, 163, 184, 0.7);
}

.math-concept {
    display: grid;
    grid-template-columns: 1.5fr 1fr;
    gap: 2rem;
    align-items: center;
}

@media (max-width: 768px) {
    .math-concept {
        grid-template-columns: 1fr;
    }

    .tab-btn {
        padding: 1rem 1.2rem;
        font-size: 0.75rem;
    }

    .tab-content {
        padding: 1.5rem;
    }
}

.math-formulas {
    background-color: var(--math-bg);
    border: 1px solid var(--commentary-border);
    border-radius: 10px;
    padding: 1.5rem;
    font-family: var(--font-mono);
    display: flex;
    flex-direction: column;
    gap: 1rem;
    color: var(--accent);
}

.math-formulas div {
    border-bottom: 1px solid var(--commentary-border);
    padding-bottom: 0.5rem;
}

.math-formulas div:last-child {
    border: none;
    padding: 0;
}

.math-formulas span {
    color: var(--text-primary);
}

.references-list {
    display: flex;
    flex-direction: column;
    gap: 1.25rem;
}

.reference-item {
    font-size: 0.88rem;
    color: var(--text-secondary);
    line-height: 1.6;
    padding-left: 2rem;
    text-indent: -2rem;
}

.reference-item strong {
    color: var(--text-primary);
}

.reference-item a {
    color: var(--accent);
    text-decoration: none;
    transition: color 0.2s ease, text-decoration 0.2s ease;
}

.reference-item a:hover {
    color: #60a5fa;
    text-decoration: underline;
}

/* Site Footer */
.site-footer {
    padding: 4rem 0 2rem 0;
    border-top: 1px solid var(--border-color);
    background: linear-gradient(to top, rgba(2, 6, 23, 0.9), transparent);
    color: var(--text-secondary);
    margin-top: auto;
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.8rem;
}

.secure-badge {
    font-family: var(--font-mono);
    font-size: 0.75rem;
    letter-spacing: 0.05em;
    color: rgba(148, 163, 184, 0.4);
}

@media (max-width: 640px) {
    .footer-bottom {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }
}

/* Theme Toggle Button & Layout */
.header-actions {
    display: flex;
    align-items: center;
    gap: 1.5rem;
}

.theme-toggle-btn {
    background: var(--commentary-bg);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: 0.5rem 0.85rem;
    border-radius: 8px;
    font-size: 0.75rem;
    font-weight: 700;
    letter-spacing: 0.05em;
    text-transform: uppercase;
    cursor: pointer;
    transition: all 0.3s ease;
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.theme-toggle-btn:hover {
    border-color: var(--border-hover);
    background-color: var(--border-color);
}