/* ============================================
   JEREMY CONDAMINE - MAIN STYLES
   ============================================ */

/* CSS Variables - Design System */
:root {
    /* Colors - Light Theme (Default) */
    --bg-color: #FAFAFA;
    --bg-dark: #F4F4F5;
    --text-main: #18181B;
    --text-muted: #52525B;
    --text-light: #71717A;
    --accent: #E4E4E7;
    --accent-blue: #3B82F6;
    --white: #FFFFFF;
    --border-color: rgba(0, 0, 0, 0.1);
    --card-bg: #FFFFFF;
    --shadow-color: rgba(0, 0, 0, 0.1);
    --footer-bg: #18181B;
    --footer-text: #FAFAFA;

    /* Typography */
    --font-heading: 'Space Grotesk', sans-serif;
    --font-body: 'Archivo', sans-serif;

    /* Font Sizes */
    --text-xs: 0.75rem;
    --text-sm: 0.875rem;
    --text-base: 1rem;
    --text-lg: 1.125rem;
    --text-xl: 1.25rem;
    --text-2xl: 1.5rem;
    --text-3xl: 1.875rem;
    --text-4xl: 2.25rem;
    --text-5xl: 3rem;
    --text-6xl: 3.75rem;

    /* Spacing */
    --space-1: 0.25rem;
    --space-2: 0.5rem;
    --space-3: 0.75rem;
    --space-4: 1rem;
    --space-5: 1.25rem;
    --space-6: 1.5rem;
    --space-8: 2rem;
    --space-10: 2.5rem;
    --space-12: 3rem;
    --space-16: 4rem;
    --space-20: 5rem;
    --space-24: 6rem;

    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-base: 0.3s ease;
    --transition-smooth: cubic-bezier(0.16, 1, 0.3, 1);

    /* Shadows */
    --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px rgba(0, 0, 0, 0.15);

    /* Border Radius */
    --radius-sm: 4px;
    --radius-md: 8px;
    --radius-lg: 12px;
    --radius-xl: 16px;
    --radius-full: 9999px;

    /* Container */
    --container-max: 1280px;
    --container-padding: 5%;
}

/* Dark Theme Variables */
[data-theme="dark"] {
    --bg-color: #09090B;
    --bg-dark: #18181B;
    --text-main: #FAFAFA;
    --text-muted: #A1A1AA;
    --text-light: #71717A;
    --accent: #27272A;
    --accent-blue: #3B82F6;
    --white: #FFFFFF;
    --border-color: rgba(255, 255, 255, 0.1);
    --card-bg: #18181B;
    --shadow-color: rgba(0, 0, 0, 0.4);
    --footer-bg: #18181B;
    --footer-text: #FAFAFA;
}

/* Light Theme Variables - Explicit override */
[data-theme="light"] {
    --bg-color: #FAFAFA;
    --bg-dark: #F4F4F5;
    --text-main: #18181B;
    --text-muted: #52525B;
    --text-light: #71717A;
    --accent: #E4E4E7;
    --accent-blue: #3B82F6;
    --white: #FFFFFF;
    --border-color: rgba(0, 0, 0, 0.1);
    --card-bg: #FFFFFF;
    --shadow-color: rgba(0, 0, 0, 0.1);
    --footer-bg: #18181B;
    --footer-text: #FAFAFA;
}

/* Respect system preference if no manual choice */
@media (prefers-color-scheme: dark) {
    :root:not([data-theme]) {
        --bg-color: #09090B;
        --bg-dark: #18181B;
        --text-main: #FAFAFA;
        --text-muted: #A1A1AA;
        --text-light: #71717A;
        --accent: #27272A;
        --accent-blue: #3B82F6;
        --white: #FFFFFF;
        --border-color: rgba(255, 255, 255, 0.1);
        --card-bg: #18181B;
        --shadow-color: rgba(0, 0, 0, 0.4);
        --footer-bg: #18181B;
        --footer-text: #FAFAFA;
    }
}

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

html {
    scroll-behavior: smooth;
    font-size: 16px;
}

body {
    font-family: var(--font-body);
    background-color: var(--bg-color);
    color: var(--text-main);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    overflow-x: hidden;
    transition: background-color var(--transition-base), color var(--transition-base);
}

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

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

ul {
    list-style: none;
}

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

/* Section */
.section {
    padding: var(--space-24) 0;
}

/* Typography */
h1,
h2,
h3,
h4,
h5,
h6 {
    font-family: var(--font-heading);
    font-weight: 500;
    line-height: 1.2;
    color: var(--text-main);
    transition: color var(--transition-base);
}

/* ============================================
   THEME TOGGLE BUTTON
   ============================================ */
.theme-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 44px;
    height: 44px;
    background: transparent;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    cursor: pointer;
    padding: 0;
    transition: all var(--transition-base);
    color: var(--text-main);
}

.theme-toggle:hover {
    background: var(--card-bg);
    border-color: var(--accent-blue);
    transform: scale(1.05);
}

.theme-toggle:focus-visible {
    outline: 2px solid var(--accent-blue);
    outline-offset: 2px;
}

.theme-toggle svg {
    width: 22px;
    height: 22px;
    transition: transform var(--transition-base);
}

.theme-toggle:hover svg {
    transform: rotate(15deg);
}

/* Sun icon (shown in dark mode) */
.theme-toggle .sun-icon {
    display: none;
}

/* Moon icon (shown in light mode) */
.theme-toggle .moon-icon {
    display: block;
}

/* Dark mode: show sun, hide moon */
[data-theme="dark"] .theme-toggle .sun-icon {
    display: block;
}

[data-theme="dark"] .theme-toggle .moon-icon {
    display: none;
}

/* System dark mode preference */
@media (prefers-color-scheme: dark) {
    :root:not([data-theme]) .theme-toggle .sun-icon {
        display: block;
    }

    :root:not([data-theme]) .theme-toggle .moon-icon {
        display: none;
    }
}

/* Header transparent variant - white icons (only when dark hero is present) */
.header--transparent.has-dark-hero .theme-toggle {
    color: #FFFFFF;
    border-color: rgba(255, 255, 255, 0.3);
}

.header--transparent.has-dark-hero .theme-toggle:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: #FFFFFF;
}

.header--transparent.has-dark-hero.scrolled .theme-toggle {
    color: var(--text-main);
    border-color: var(--border-color);
}

.header--transparent.has-dark-hero.scrolled .theme-toggle:hover {
    background: var(--card-bg);
    border-color: var(--accent-blue);
}

/* ============================================
   NAVIGATION - Enhanced with Glassmorphism
   ============================================ */
.header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: rgba(250, 250, 250, 0.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
    transition: all var(--transition-base);
}

[data-theme="dark"] .header {
    background: rgba(9, 9, 11, 0.95);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

@media (prefers-color-scheme: dark) {
    :root:not([data-theme]) .header {
        background: rgba(9, 9, 11, 0.95);
        border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    }
}

.header .nav-link {
    color: var(--text-main);
    text-shadow: none;
}

.header .nav-link::after {
    background: var(--accent-blue);
}

.header .hamburger,
.header .hamburger::before,
.header .hamburger::after {
    background: var(--text-main);
}

/* Header transparent variant for pages with dark hero (homepage) */
/* Only applies when a dark hero background is actually present */
.header--transparent.has-dark-hero {
    background: transparent;
    backdrop-filter: none;
    -webkit-backdrop-filter: none;
    border-bottom: none;
}

/* En mode transparent sur hero sombre : liens blancs pour le contraste */
.header--transparent.has-dark-hero:not(.scrolled) .nav-link {
    color: #FFFFFF !important;
    text-shadow: 0 1px 3px rgba(0, 0, 0, 0.3) !important;
}

.header--transparent.has-dark-hero:not(.scrolled) .nav-link::after {
    background: #FFFFFF !important;
}

.header--transparent.has-dark-hero:not(.scrolled) .hamburger,
.header--transparent.has-dark-hero:not(.scrolled) .hamburger::before,
.header--transparent.has-dark-hero:not(.scrolled) .hamburger::after {
    background: #FFFFFF !important;
}

/* Theme toggle contrast over dark hero */
.header--transparent.has-dark-hero:not(.scrolled) .theme-toggle {
    color: #FFFFFF !important;
    border-color: rgba(255, 255, 255, 0.3) !important;
}

.header--transparent.has-dark-hero:not(.scrolled) .theme-toggle:hover {
    background: rgba(255, 255, 255, 0.1) !important;
    border-color: #FFFFFF !important;
}

/* Retour aux couleurs normales lors du scroll */
.header.scrolled .nav-link,
.header--transparent.scrolled .nav-link {
    color: var(--text-main) !important;
    text-shadow: none !important;
}

.header.scrolled .nav-link::after,
.header--transparent.scrolled .nav-link::after {
    background: var(--accent-blue) !important;
}

/* Par défaut (sans data-theme) et préférence système sombre */
@media (prefers-color-scheme: dark) {
    :root:not([data-theme]) .header--transparent.has-dark-hero .nav-link {
        color: #FFFFFF;
        text-shadow: 0 1px 3px rgba(0, 0, 0, 0.5);
    }

    :root:not([data-theme]) .header--transparent.has-dark-hero .nav-link::after {
        background: #FFFFFF;
    }

    :root:not([data-theme]) .header--transparent.has-dark-hero .hamburger,
    :root:not([data-theme]) .header--transparent.has-dark-hero .hamburger::before,
    :root:not([data-theme]) .header--transparent.has-dark-hero .hamburger::after {
        background: #FFFFFF;
    }
}

/* When transparent header is over a dark hero but user has scrolled */
.header--transparent.has-dark-hero.scrolled {
    background: rgba(250, 250, 250, 0.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    box-shadow: 0 4px 30px rgba(0, 0, 0, 0.1);
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
}

[data-theme="dark"] .header--transparent.has-dark-hero.scrolled {
    background: rgba(9, 9, 11, 0.95);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

@media (prefers-color-scheme: dark) {
    :root:not([data-theme]) .header--transparent.has-dark-hero.scrolled {
        background: rgba(9, 9, 11, 0.95);
        border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    }
}

.header--transparent.has-dark-hero.scrolled .nav-link {
    color: var(--text-main) !important;
    text-shadow: none !important;
}

.header--transparent.has-dark-hero.scrolled .nav-link::after {
    background: var(--accent-blue);
}

.header--transparent.has-dark-hero.scrolled .hamburger,
.header--transparent.has-dark-hero.scrolled .hamburger::before,
.header--transparent.has-dark-hero.scrolled .hamburger::after {
    background: var(--text-main) !important;
}

/* ── SAFETY NET ──────────────────────────────────────────────────────────────
   Quand le header a un fond clair (scrolled ou pas de hero sombre),
   les liens de navigation doivent TOUJOURS être visibles en couleur sombre.
   Cela couvre tous les cas où le fond est blanc/clair.
   ─────────────────────────────────────────────────────────────────────────── */
.header.scrolled .nav-link,
.header--transparent.scrolled .nav-link {
    color: var(--text-main) !important;
    text-shadow: none !important;
}

.header.scrolled .hamburger,
.header.scrolled .hamburger::before,
.header.scrolled .hamburger::after,
.header--transparent.scrolled .hamburger,
.header--transparent.scrolled .hamburger::before,
.header--transparent.scrolled .hamburger::after {
    background: var(--text-main) !important;
}

[data-theme="dark"] .header.scrolled .nav-link,
[data-theme="dark"] .header--transparent.scrolled .nav-link {
    color: var(--text-main) !important;
}

[data-theme="dark"] .header.scrolled .hamburger,
[data-theme="dark"] .header.scrolled .hamburger::before,
[data-theme="dark"] .header.scrolled .hamburger::after,
[data-theme="dark"] .header--transparent.scrolled .hamburger,
[data-theme="dark"] .header--transparent.scrolled .hamburger::before,
[data-theme="dark"] .header--transparent.scrolled .hamburger::after {
    background: var(--text-main) !important;
}

/* Fallback: transparent header without dark hero — use normal dark text */
.header--transparent:not(.has-dark-hero) {
    background: rgba(250, 250, 250, 0.95);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid rgba(0, 0, 0, 0.05);
}

.header--transparent:not(.has-dark-hero) .nav-link {
    color: var(--text-main);
    text-shadow: none;
}

.header--transparent:not(.has-dark-hero) .nav-link::after {
    background: var(--accent-blue);
}

.header--transparent:not(.has-dark-hero) .hamburger,
.header--transparent:not(.has-dark-hero) .hamburger::before,
.header--transparent:not(.has-dark-hero) .hamburger::after {
    background: var(--text-main);
}

[data-theme="dark"] .header--transparent:not(.has-dark-hero) {
    background: rgba(9, 9, 11, 0.95);
    border-bottom: 1px solid rgba(255, 255, 255, 0.05);
}

@media (prefers-color-scheme: dark) {
    :root:not([data-theme]) .header--transparent:not(.has-dark-hero) {
        background: rgba(9, 9, 11, 0.95);
        border-bottom: 1px solid rgba(255, 255, 255, 0.05);
    }
}

.nav {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--space-4) var(--container-padding);
    max-width: var(--container-max);
    margin: 0 auto;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: var(--space-4);
}

.nav-actions {
    display: flex;
    align-items: center;
    gap: var(--space-3);
    margin-left: auto;
}

.logo {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 48px;
    height: 48px;
    background: linear-gradient(135deg, var(--accent), #27272a);
    color: var(--white);
    border-radius: var(--radius-md);
    font-family: var(--font-heading);
    font-weight: 700;
    font-size: var(--text-xl);
    transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.2);
}

.logo:hover {
    transform: scale(1.05) rotate(-2deg);
    background: linear-gradient(135deg, var(--accent-blue), #3B82F6);
    box-shadow: 0 8px 25px rgba(37, 99, 235, 0.3);
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: var(--space-8);
}

.nav-link {
    font-family: var(--font-heading);
    font-size: var(--text-sm);
    font-weight: 500;
    color: var(--text-main);
    position: relative;
    padding: var(--space-2) 0;
    transition: color var(--transition-base), text-shadow var(--transition-base);
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--accent-blue);
    transition: width var(--transition-smooth);
}

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

/* Mobile Navigation Toggle */
.nav-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--space-2);
    z-index: 1001;
}

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

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

.hamburger::before {
    top: -8px;
}

.hamburger::after {
    top: 8px;
}

.nav-toggle[aria-expanded="true"] .hamburger {
    background: transparent;
}

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

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

/* ============================================
   BUTTONS
   ============================================ */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: var(--space-2);
    font-family: var(--font-heading);
    font-size: var(--text-sm);
    font-weight: 500;
    padding: var(--space-3) var(--space-6);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: all var(--transition-smooth);
    border: none;
    text-decoration: none;
}

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

.btn-primary:hover {
    background: var(--accent-blue);
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
}

.btn-outline {
    background: transparent;
    color: var(--text-main);
    border: 1px solid var(--text-main);
}

.btn-outline:hover {
    background: var(--text-main);
    color: var(--white);
    transform: translateY(-2px);
}

.btn-text {
    background: transparent;
    color: var(--text-main);
    padding: var(--space-2) 0;
    position: relative;
}

.btn-text::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 1px;
    background: currentColor;
    transition: width var(--transition-smooth);
}

.btn-text:hover::after {
    width: 100%;
}

.btn-large {
    padding: var(--space-4) var(--space-8);
    font-size: var(--text-base);
}

/* ============================================
   PAGE HEADER
   ============================================ */
.page-header {
    padding: calc(var(--space-24) + 80px) 0 var(--space-16);
    background: var(--bg-color);
    text-align: center;
    transition: background-color var(--transition-base);
}

.page-title {
    font-size: clamp(2.5rem, 6vw, 4rem);
    font-weight: 300;
    margin-bottom: var(--space-4);
}

.page-subtitle {
    font-size: var(--text-lg);
    color: var(--text-muted);
    max-width: 600px;
    margin: 0 auto;
}

/* ============================================
   FOOTER
   ============================================ */
.footer {
    background: var(--footer-bg, var(--accent));
    color: var(--footer-text, var(--white));
    padding: var(--space-16) 0 var(--space-8);
    transition: background-color var(--transition-base), color var(--transition-base);
}

[data-theme="dark"] .footer {
    background: var(--footer-bg);
    color: var(--footer-text);
}

@media (prefers-color-scheme: dark) {
    :root:not([data-theme]) .footer {
        background: var(--footer-bg);
        color: var(--footer-text);
    }
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    gap: var(--space-8);
    margin-bottom: var(--space-12);
}

.footer-logo {
    font-family: var(--font-heading);
    font-size: var(--text-3xl);
    font-weight: 700;
    display: block;
    margin-bottom: var(--space-4);
}

.footer-tagline {
    color: var(--text-light);
    font-size: var(--text-sm);
    line-height: 1.6;
}

.footer-title {
    font-size: var(--text-sm);
    font-weight: 600;
    margin-bottom: var(--space-4);
    color: var(--white);
}

.footer-nav ul {
    display: flex;
    flex-direction: column;
    gap: var(--space-3);
}

.footer-nav a,
.footer-contact a {
    color: var(--text-light);
    font-size: var(--text-sm);
    transition: color var(--transition-base);
}

.footer-nav a:hover,
.footer-contact a:hover {
    color: var(--white);
}

.footer-contact address {
    font-style: normal;
    display: flex;
    flex-direction: column;
    gap: var(--space-2);
}

.footer-contact p {
    color: var(--text-light);
    font-size: var(--text-sm);
}

.social-links {
    display: flex;
    gap: var(--space-4);
}

.social-links a {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: var(--radius-full);
    transition: all var(--transition-base);
}

.social-links a:hover {
    background: var(--white);
    border-color: var(--white);
    color: var(--accent);
}

.social-links svg {
    width: 18px;
    height: 18px;
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: var(--space-6);
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: var(--space-4);
}

.copyright,
.credits {
    color: var(--text-light);
    font-size: var(--text-xs);
}

/* ============================================
   ANIMATIONS
   ============================================ */
.reveal-text {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s var(--transition-smooth), transform 0.8s var(--transition-smooth);
}

.reveal-text.revealed {
    opacity: 1;
    transform: translateY(0);
}

/* ============================================
   RESPONSIVE
   ============================================ */
@media (max-width: 968px) {
    .nav-toggle {
        display: block;
    }

    .nav-menu {
        position: fixed;
        top: 0;
        right: -100%;
        width: 100%;
        height: 100vh;
        background: var(--bg-color);
        flex-direction: column;
        justify-content: center;
        align-items: center;
        gap: var(--space-6);
        transition: right var(--transition-smooth);
    }

    .nav-menu.active {
        right: 0;
    }

    .nav-link {
        font-size: var(--text-xl);
    }

    .theme-toggle {
        position: absolute;
        right: 70px;
        top: 50%;
        transform: translateY(-50%);
    }

    .footer-grid {
        grid-template-columns: 1fr 1fr;
        gap: var(--space-8);
    }

    .section {
        padding: var(--space-16) 0;
    }
}

@media (max-width: 640px) {
    :root {
        --container-padding: 5%;
    }

    .footer-grid {
        grid-template-columns: 1fr;
        gap: var(--space-6);
    }

    .footer-bottom {
        flex-direction: column;
        text-align: center;
    }

    .page-header {
        padding: calc(var(--space-16) + 60px) 0 var(--space-10);
    }
}

/* ============================================
   ACCESSIBILITY
   ============================================ */
@media (prefers-reduced-motion: reduce) {

    *,
    *::before,
    *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }

    html {
        scroll-behavior: auto;
    }

    .reveal-text {
        opacity: 1;
        transform: none;
    }
}

/* Focus styles */
:focus-visible {
    outline: 2px solid var(--accent-blue);
    outline-offset: 2px;
}

/* Skip link */
.skip-link {
    position: absolute;
    top: -100%;
    left: 50%;
    transform: translateX(-50%);
    background: var(--accent);
    color: var(--white);
    padding: var(--space-3) var(--space-6);
    border-radius: var(--radius-md);
    z-index: 9999;
    transition: top var(--transition-base);
}

.skip-link:focus {
    top: var(--space-4);
}

/* ============================================
   SCROLL TO TOP BUTTON
   ============================================ */
.scroll-to-top {
    position: fixed;
    bottom: var(--space-6);
    right: var(--space-6);
    width: 48px;
    height: 48px;
    background: #6B7280;
    color: var(--white);
    border: none;
    border-radius: var(--radius-full);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: all var(--transition-smooth);
    z-index: 999;
    /* Effet 3D avec ombres multiples */
    box-shadow:
        0 4px 6px rgba(0, 0, 0, 0.3),
        0 8px 12px rgba(0, 0, 0, 0.2),
        0 12px 20px rgba(0, 0, 0, 0.15),
        inset 0 2px 4px rgba(255, 255, 255, 0.3),
        inset 0 -2px 4px rgba(0, 0, 0, 0.2);
}

.scroll-to-top.visible {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.scroll-to-top:hover {
    background: #4B5563;
    transform: translateY(-4px) scale(1.05);
    /* Effet 3D accentué au survol */
    box-shadow:
        0 8px 12px rgba(0, 0, 0, 0.4),
        0 16px 24px rgba(0, 0, 0, 0.3),
        0 24px 32px rgba(0, 0, 0, 0.2),
        inset 0 2px 4px rgba(255, 255, 255, 0.4),
        inset 0 -2px 4px rgba(0, 0, 0, 0.3);
}

.scroll-to-top:active {
    transform: translateY(-2px) scale(0.98);
    box-shadow:
        0 4px 6px rgba(0, 0, 0, 0.3),
        0 8px 12px rgba(0, 0, 0, 0.2),
        inset 0 2px 4px rgba(0, 0, 0, 0.2),
        inset 0 -2px 4px rgba(255, 255, 255, 0.1);
}

.scroll-to-top:focus-visible {
    outline: 2px solid var(--accent-blue);
    outline-offset: 2px;
}

.scroll-to-top svg {
    width: 24px;
    height: 24px;
    stroke: currentColor;
    stroke-width: 2;
    fill: none;
    transition: transform var(--transition-base);
}

.scroll-to-top:hover svg {
    transform: translateY(-2px);
}

/* Dark theme support */
[data-theme="dark"] .scroll-to-top {
    background: #6B7280;
}

[data-theme="dark"] .scroll-to-top:hover {
    background: #4B5563;
}

/* Mobile adjustments */
@media (max-width: 640px) {
    .scroll-to-top {
        width: 44px;
        height: 44px;
        bottom: var(--space-4);
        right: var(--space-4);
    }

    .scroll-to-top svg {
        width: 20px;
        height: 20px;
    }
}

/* Reduced motion support */
@media (prefers-reduced-motion: reduce) {
    .scroll-to-top {
        transition: opacity var(--transition-base), visibility var(--transition-base);
    }

    .scroll-to-top:hover {
        transform: none;
    }

    .scroll-to-top svg {
        transition: none;
    }
}