/* ==========================================================================
   Main Styles - Media Bias Visualization
   ========================================================================== */

/* CSS Custom Properties (Variables) */
:root {
    /* University of Genova Colors */
    --color-primary: #a32a26;
    /* Accent Red */
    --color-primary-dark: #cc6c27;
    --color-primary-light: #cc6c27;
    --color-secondary: #003366;
    /* Dark Blue */
    --color-secondary-light: #004C99;
    --color-accent: #FF6B35;
    /* Accent Orange */

    /* Neutral Palette */
    --color-black: #1A1A1A;
    --color-gray-900: #2D2D2D;
    --color-gray-800: #3D3D3D;
    --color-gray-700: #4D4D4D;
    --color-gray-600: #666666;
    --color-gray-500: #808080;
    --color-gray-400: #999999;
    --color-gray-300: #B3B3B3;
    --color-gray-200: #CCCCCC;
    --color-gray-100: #E6E6E6;
    --color-gray-50: #F5F5F5;
    --color-white: #FFFFFF;

    /* Semantic Colors */
    --color-positive: #2E7D32;
    --color-negative: #C62828;
    --color-neutral: #1565C0;
    --color-warning: #F9A825;
    --color-info: #0288D1;

    /* Sentiment Scale */
    --color-sentiment-negative: #C62828;
    --color-sentiment-neutral: #757575;
    --color-sentiment-positive: #2E7D32;

    /* Background Colors */
    --bg-primary: var(--color-white);
    --bg-secondary: var(--color-gray-50);
    --bg-dark: var(--color-gray-900);
    --bg-overlay: rgba(0, 0, 0, 0.7);

    /* Text Colors */
    --text-primary: var(--color-gray-900);
    --text-secondary: var(--color-gray-600);
    --text-muted: var(--color-gray-500);
    --text-light: var(--color-white);

    /* Spacing Scale */
    --space-xxs: 0.25rem;
    /* 4px */
    --space-xs: 0.5rem;
    /* 8px */
    --space-sm: 0.75rem;
    /* 12px */
    --space-md: 1rem;
    /* 16px */
    --space-lg: 1.5rem;
    /* 24px */
    --space-xl: 2rem;
    /* 32px */
    --space-xxl: 3rem;
    /* 48px */
    --space-xxxl: 4rem;
    /* 64px */

    /* Layout */
    --container-max-width: 1200px;
    --container-padding: var(--space-lg);
    --section-spacing: var(--space-xxxl);
    --header-height: 70px;

    /* Borders */
    --border-radius-sm: 4px;
    --border-radius-md: 8px;
    --border-radius-lg: 12px;
    --border-radius-xl: 20px;
    --border-color: var(--color-gray-200);

    /* Shadows */
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.08);
    --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.12);
    --shadow-xl: 0 16px 48px rgba(0, 0, 0, 0.15);

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
    --transition-slow: 400ms ease;

    /* Z-Index Scale */
    --z-base: 0;
    --z-dropdown: 100;
    --z-sticky: 200;
    --z-overlay: 300;
    --z-modal: 400;
    --z-tooltip: 500;
}

/* ==========================================================================
   Reset & Base Styles
   ========================================================================== */

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

html {
    font-size: 16px;
    scroll-behavior: smooth;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: 'Fira Sans', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    font-size: 1rem;
    font-weight: 400;
    line-height: 1.6;
    color: var(--text-primary);
    background-color: var(--bg-primary);
    overflow-x: hidden;
}

/* Selection */
::selection {
    background-color: var(--color-primary);
    color: var(--color-white);
}

/* Focus States */
:focus {
    outline: 2px solid var(--color-primary);
    outline-offset: 2px;
}

:focus:not(:focus-visible) {
    outline: none;
}

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

/* ==========================================================================
   Layout Components
   ========================================================================== */

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

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

/* ==========================================================================
   Header
   ========================================================================== */

.site-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: var(--header-height);
    background: transparent;
    backdrop-filter: none;
    border-bottom: none;
    z-index: var(--z-sticky);
    transition: transform var(--transition-base), background var(--transition-base);
}

.site-header.is-hidden {
    transform: translateY(-100%);
}

.site-header.is-scrolled {
    background: rgba(0, 20, 40, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-md);
}

.header-container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 80%;
    max-width: var(--container-max-width);
    margin: 0 auto;
    padding: 0 var(--container-padding);
}

.main-nav {
    display: flex;
    align-items: center;
}

.nav-list {
    display: flex;
    gap: var(--space-xl);
    list-style: none;
}

.nav-list a {
    color: var(--color-white);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.9375rem;
    padding: var(--space-xs) 0;
    position: relative;
    transition: color var(--transition-fast);
}

.nav-list a:visited,
.nav-list a:active,
.nav-list a:focus {
    color: var(--color-white);
}

.nav-list a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--color-white);
    transition: width var(--transition-base);
}

.nav-list a:hover {
    color: rgba(255, 255, 255, 0.8);
}

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

.nav-toggle {
    display: none;
    flex-direction: column;
    justify-content: center;
    width: 40px;
    height: 40px;
    background: none;
    border: none;
    cursor: pointer;
}

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

.hamburger::before,
.hamburger::after {
    content: '';
    position: absolute;
    left: 0;
    width: 100%;
    height: 2px;
    background-color: var(--text-primary);
    transition: transform var(--transition-base);
}

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

.hamburger::after {
    bottom: -7px;
}

/* ==========================================================================
   Hero Section
   ========================================================================== */

.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: url('../assets/images/heading-background.png') center center / cover no-repeat;
    overflow: hidden;
}

.hero::before {
    content: '';
    position: absolute;
    inset: 0;
    background: rgba(0, 20, 40, 0.4);
    z-index: 0;
}

.hero-background {
    position: absolute;
    inset: 0;
    z-index: 0;
}

.hero-particles {
    position: absolute;
    inset: 0;
    opacity: 0.3;
}

.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    padding: var(--space-xxl) var(--container-padding);
    max-width: 900px;
}

.hero-tagline {
    font-family: 'Fira Sans', sans-serif;
    font-size: clamp(0.875rem, 2vw, 1.125rem);
    font-weight: 400;
    color: rgba(255, 255, 255, 0.7);
    text-transform: uppercase;
    letter-spacing: 0.15em;
    margin-bottom: var(--space-sm);
}

.hero-subtitle {
    font-size: clamp(1.125rem, 2.5vw, 1.5rem);
    font-weight: 300;
    line-height: 1.6;
    color: rgba(255, 255, 255, 0.85);
    margin-bottom: var(--space-xl);
}

.hero-badge {
    display: inline-block;
    margin-bottom: var(--space-lg);
}

.hero-badge span {
    display: inline-block;
    padding: var(--space-xs) var(--space-md);
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: var(--border-radius-xl);
    color: var(--color-white);
    font-size: 0.875rem;
    font-weight: 500;
    letter-spacing: 0.05em;
    text-transform: uppercase;
}

.group-name {
    font-family: 'Roboto Slab', Georgia, serif;
    font-size: clamp(1.5rem, 4vw, 2.25rem);
    font-weight: 700;
    color: var(--color-white);
    margin-bottom: var(--space-lg);
    letter-spacing: 0.02em;
    text-shadow: 0 2px 20px rgba(0, 0, 0, 0.3);
}

.team-members {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: var(--space-md);
    flex-wrap: wrap;
    margin-bottom: var(--space-xxl);
}

.team-member-badge {
    display: inline-block;
    padding: var(--space-sm) var(--space-lg);
    background: rgba(255, 255, 255, 0.15);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: var(--border-radius-xl);
    color: var(--color-white);
    font-size: 1rem;
    font-weight: 500;
    transition: all 0.3s ease;
    text-decoration: none;
}

.team-member-badge:hover {
    background: rgba(255, 255, 255, 0.25);
    transform: translateY(-2px);
}

.team-member-badge:visited {
    color: var(--color-white);
}

.hero-title {
    font-family: 'Roboto Slab', Georgia, serif;
    font-size: clamp(2.5rem, 8vw, 5rem);
    font-weight: 700;
    line-height: 1.1;
    color: rgb(198, 83, 41);
    margin-bottom: var(--space-lg);
}

.title-line {
    display: block;
}

.title-line.accent {
    color: var(--color-primary-light);
}

.hero-subtitle {
    font-size: clamp(1.125rem, 2.5vw, 1.375rem);
    font-weight: 300;
    line-height: 1.6;
    color: rgba(255, 255, 255, 0.85);
    margin-bottom: var(--space-xxl);
}

.hero-cta {
    display: flex;
    gap: var(--space-md);
    justify-content: center;
    flex-wrap: wrap;
    margin-bottom: var(--space-xxxl);
}

.scroll-indicator {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--space-sm);
    color: rgba(255, 255, 255, 0.6);
    font-size: 0.875rem;
    animation: pulse 2s infinite;
    text-decoration: none;
    transition: color var(--transition-fast);
}

.scroll-indicator:hover {
    color: var(--color-white);
    cursor: pointer;
}

.scroll-indicator:visited,
.scroll-indicator:active,
.scroll-indicator:focus {
    color: rgba(255, 255, 255, 0.6);
}

.scroll-arrow {
    width: 24px;
    height: 24px;
    border-right: 2px solid currentColor;
    border-bottom: 2px solid currentColor;
    transform: rotate(45deg);
}

@keyframes pulse {

    0%,
    100% {
        opacity: 0.6;
        transform: translateY(0);
    }

    50% {
        opacity: 1;
        transform: translateY(5px);
    }
}

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

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-xs);
    padding: var(--space-sm) var(--space-xl);
    font-family: inherit;
    font-size: 1rem;
    font-weight: 500;
    line-height: 1.5;
    text-decoration: none;
    border: 2px solid transparent;
    border-radius: var(--border-radius-md);
    cursor: pointer;
    transition: all var(--transition-fast);
}

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

.btn-primary:hover {
    background-color: var(--color-primary-dark);
    border-color: var(--color-primary-dark);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(207, 0, 99, 0.3);
}

.btn-secondary {
    background-color: transparent;
    color: var(--color-white);
    border-color: rgba(255, 255, 255, 0.4);
}

.btn-secondary:hover {
    background-color: rgba(255, 255, 255, 0.1);
    border-color: var(--color-white);
}

/* ==========================================================================
   Section Headers
   ========================================================================== */

.section-header {
    text-align: center;
    margin-bottom: var(--space-xxl);
}

.section-number {
    display: block;
    font-family: 'Roboto Slab', Georgia, serif;
    font-size: 0.875rem;
    font-weight: 700;
    color: var(--color-primary);
    letter-spacing: 0.1em;
    margin-bottom: var(--space-sm);
}

.section-title {
    font-family: 'Roboto Slab', Georgia, serif;
    font-size: clamp(1.75rem, 4vw, 2.5rem);
    font-weight: 700;
    color: var(--text-primary);
    margin-bottom: var(--space-md);
}

.section-description {
    font-size: 1.125rem;
    color: var(--text-secondary);
    max-width: 700px;
    margin: 0 auto;
}

/* ==========================================================================
   Intro Section
   ========================================================================== */

.intro-section {
    background: var(--bg-secondary);
}

.intro-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--space-xxl);
    align-items: center;
}

.intro-text .lead {
    font-size: 1.25rem;
    font-weight: 500;
    line-height: 1.5;
    color: var(--text-primary);
    margin-bottom: var(--space-lg);
}

.intro-text p {
    margin-bottom: var(--space-md);
    color: var(--text-secondary);
}

.data-highlight {
    display: flex;
    gap: var(--space-xl);
    margin-top: var(--space-xl);
    padding-top: var(--space-xl);
    border-top: 1px solid var(--border-color);
}

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

.highlight-number {
    display: block;
    font-family: 'Roboto Slab', Georgia, serif;
    font-size: 2.5rem;
    font-weight: 700;
    color: var(--color-primary);
    line-height: 1;
    margin-bottom: var(--space-xs);
}

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

.intro-visual {
    background: var(--bg-primary);
    border-radius: var(--border-radius-lg);
    box-shadow: var(--shadow-lg);
    padding: var(--space-lg);
    height: auto;
    width: fit-content;
    max-width: 100%;
    margin: 0 auto;
    display: flex;
    align-items: center;
    justify-content: center;
    overflow: hidden;
}

.intro-image {
    max-height: 400px;
    width: auto;
    max-width: 100%;
    object-fit: contain;
    display: block;
}

/* ==========================================================================
   Methodology Section
   ========================================================================== */

.methodology-section {
    background: var(--bg-secondary);
}

.methodology-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-lg);
}

.method-card {
    background: var(--bg-primary);
    border-radius: var(--border-radius-lg);
    padding: var(--space-xl);
    box-shadow: var(--shadow-sm);
    border: 1px solid var(--border-color);
    transition: transform var(--transition-base), box-shadow var(--transition-base);
}

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

.method-icon {
    width: 48px;
    height: 48px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-gray-100);
    border-radius: var(--border-radius-md);
    margin-bottom: var(--space-md);
    color: var(--color-primary);
}

.method-icon svg {
    width: 24px;
    height: 24px;
}

.method-card h3 {
    font-family: 'Roboto Slab', Georgia, serif;
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--space-sm);
}

.method-card>p {
    color: var(--text-secondary);
    margin-bottom: var(--space-md);
}

.method-details,
.method-steps,
.limitations-list,
.tech-list {
    padding-left: var(--space-lg);
    color: var(--text-secondary);
    font-size: 0.9375rem;
}

.method-details li,
.method-steps li,
.limitations-list li,
.tech-list li {
    margin-bottom: var(--space-xs);
}

.method-caveat {
    margin-top: var(--space-md);
    padding: var(--space-md);
    background: rgba(249, 168, 37, 0.1);
    border-left: 3px solid var(--color-warning);
    border-radius: 0 var(--border-radius-sm) var(--border-radius-sm) 0;
    font-size: 0.875rem;
    color: var(--text-primary);
}

/* ==========================================================================
   About Section
   ========================================================================== */

.about-section {
    background: var(--bg-primary);
}

.about-content {
    max-width: 800px;
    margin: 0 auto;
}

.project-info,
.team-section,
.acknowledgments,
.citation {
    margin-bottom: var(--space-xxl);
}

.project-info h3,
.team-section h3,
.acknowledgments h3,
.citation h3 {
    font-family: 'Roboto Slab', Georgia, serif;
    font-size: 1.375rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--space-md);
}

.project-info p {
    color: var(--text-secondary);
    margin-bottom: var(--space-md);
}

.team-grid {
    display: grid;
    gap: var(--space-lg);
}

.team-member {
    display: flex;
    gap: var(--space-lg);
    padding: var(--space-lg);
    background: var(--bg-secondary);
    border-radius: var(--border-radius-lg);
}

.member-avatar {
    width: 64px;
    height: 64px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--color-primary);
    color: var(--color-white);
    font-family: 'Roboto Slab', Georgia, serif;
    font-size: 1.25rem;
    font-weight: 700;
    border-radius: 50%;
    flex-shrink: 0;
}

.member-info h4 {
    font-family: 'Roboto Slab', Georgia, serif;
    font-size: 1.125rem;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: var(--space-xxs);
}

.member-role {
    display: block;
    font-size: 0.875rem;
    color: var(--color-primary);
    font-weight: 500;
    margin-bottom: var(--space-xs);
}

.member-info p {
    font-size: 0.9375rem;
    color: var(--text-secondary);
}

.acknowledgments ul {
    list-style: none;
    padding-left: 0;
}

.acknowledgments li {
    padding-left: var(--space-lg);
    position: relative;
    color: var(--text-secondary);
    margin-bottom: var(--space-sm);
}

.acknowledgments li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: var(--color-primary);
}

.citation-box {
    padding: var(--space-lg);
    background: var(--bg-secondary);
    border-radius: var(--border-radius-md);
    border-left: 3px solid var(--color-primary);
}

.citation-box code {
    display: block;
    font-family: 'Fira Code', Consolas, monospace;
    font-size: 0.875rem;
    line-height: 1.6;
    color: var(--text-secondary);
    word-break: break-word;
}

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

.site-footer {
    background: var(--color-gray-900);
    color: var(--color-white);
    padding: var(--space-xxl) 0 var(--space-lg);
}

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

.footer-main {
    display: grid;
    grid-template-columns: 1.5fr 2fr;
    gap: var(--space-xxl);
    padding-bottom: var(--space-xl);
    border-bottom: 1px solid var(--color-gray-700);
}

.footer-logo {
    height: 50px;
    width: auto;
    filter: brightness(0) invert(1);
    margin-bottom: var(--space-md);
}

.footer-title {
    font-family: 'Roboto Slab', Georgia, serif;
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--color-primary);
    margin-bottom: var(--space-md);
}

.footer-brand p {
    color: var(--color-gray-400);
    font-size: 0.9375rem;
    max-width: 300px;
}

.footer-links {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--space-xl);
}

.footer-column h4 {
    font-family: 'Roboto Slab', Georgia, serif;
    font-size: 0.9375rem;
    font-weight: 600;
    color: var(--color-white);
    margin-bottom: var(--space-md);
}

.footer-column ul {
    list-style: none;
}

.footer-column li {
    margin-bottom: var(--space-xs);
}

.footer-column a {
    color: var(--color-gray-400);
    text-decoration: none;
    font-size: 0.9375rem;
    transition: color var(--transition-fast);
}

.footer-column a:visited,
.footer-column a:active,
.footer-column a:focus {
    color: var(--color-gray-400);
}

.footer-column a:hover {
    color: var(--color-white);
}

.footer-bottom {
    padding-top: var(--space-lg);
    text-align: center;
}

.copyright {
    font-size: 0.875rem;
    color: var(--color-gray-500);
    margin-bottom: var(--space-xs);
}

.copyright a {
    color: var(--color-gray-400);
}

.disclaimer {
    font-size: 0.8125rem;
    color: var(--color-gray-600);
    font-style: italic;
}

/* ==========================================================================
   Tooltip
   ========================================================================== */

.tooltip {
    position: fixed;
    padding: var(--space-sm) var(--space-md);
    background: var(--color-gray-900);
    color: var(--color-white);
    font-size: 0.875rem;
    border-radius: var(--border-radius-md);
    pointer-events: none;
    opacity: 0;
    transform: translateY(10px);
    transition: opacity var(--transition-fast), transform var(--transition-fast);
    z-index: var(--z-tooltip);
    max-width: 300px;
    box-shadow: var(--shadow-lg);
}

.tooltip.is-visible {
    opacity: 1;
    transform: translateY(0);
}

.tooltip-title {
    font-weight: 600;
    margin-bottom: var(--space-xxs);
}

.tooltip-value {
    color: var(--color-primary-light);
}

.tooltip-secondary {
    font-size: 0.8125rem;
    color: var(--color-gray-400);
    margin-top: var(--space-xxs);
}

/* ==========================================================================
   Loading Overlay
   ========================================================================== */

.loading-overlay {
    position: fixed;
    inset: 0;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: var(--bg-primary);
    z-index: var(--z-modal);
    transition: opacity var(--transition-slow);
}

.loading-overlay.is-hidden {
    opacity: 0;
    pointer-events: none;
}

.loading-spinner {
    width: 48px;
    height: 48px;
    border: 3px solid var(--color-gray-200);
    border-top-color: var(--color-primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

.loading-overlay p {
    margin-top: var(--space-md);
    color: var(--text-secondary);
}

/* ==========================================================================
   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;
}

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

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

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

.mt-0 {
    margin-top: 0;
}

.mt-sm {
    margin-top: var(--space-sm);
}

.mt-md {
    margin-top: var(--space-md);
}

.mt-lg {
    margin-top: var(--space-lg);
}

.mt-xl {
    margin-top: var(--space-xl);
}

.mb-0 {
    margin-bottom: 0;
}

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

.mb-md {
    margin-bottom: var(--space-md);
}

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

.mb-xl {
    margin-bottom: var(--space-xl);
}