/* ==========================================================================
   Design System & Premium Styling - solution-mairie.fr
   ========================================================================== */

/* --- 1. Définition des Thèmes (Variables CSS) --- */

/* Thème Sombre (Par Défaut) */
:root {
    --bg-main: #0b0f19;
    --bg-surface: rgba(22, 28, 45, 0.6);
    --bg-surface-hover: rgba(22, 28, 45, 0.85);
    --bg-alt: #070a10;
    --border-color: rgba(255, 255, 255, 0.07);
    --border-hover: rgba(5, 150, 105, 0.35);
    
    --color-primary: #059669; /* Vert Émeraude */
    --color-primary-hover: #047857;
    --color-secondary: #0d9488; /* Cyan / Teal */
    --color-secondary-hover: #0f766e;
    --color-accent: #d97706; /* Ambre / Or */
    --color-accent-hover: #b45309;
    
    --text-primary: #f8fafc;
    --text-secondary: #94a3b8;
    --text-muted: #475569;
    
    --shadow-premium: 0 15px 30px -10px rgba(0, 0, 0, 0.5);
    --shadow-glow: 0 0 25px rgba(5, 150, 105, 0.2);
    --glass-blur: blur(16px);
}

/* Thème Clair */
[data-theme="light"] {
    --bg-main: #ffffff;
    --bg-surface: #f8fafc;
    --bg-surface-hover: #ffffff;
    --bg-alt: #f1f5f9;
    --border-color: rgba(15, 23, 42, 0.08);
    --border-hover: rgba(5, 150, 105, 0.4);
    
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-muted: #64748b;
    
    --shadow-premium: 0 10px 25px -5px rgba(15, 23, 42, 0.05);
    --shadow-glow: 0 0 20px rgba(5, 150, 105, 0.1);
}

/* --- 2. Initialisation & Styles Globaux --- */
* {
    box-sizing: border-box;
    margin: 0;
    padding: 0;
}

html {
    scroll-behavior: smooth;
    scroll-padding-top: 7.5rem;
    font-size: 16px;
    overflow-x: hidden;
}

body {
    background-color: var(--bg-main);
    color: var(--text-primary);
    font-family: 'Inter', system-ui, sans-serif;
    line-height: 1.5;
    overflow-x: hidden;
    position: relative;
    -webkit-font-smoothing: antialiased;
    transition: background-color 0.3s ease, color 0.3s ease;
}

/* Blobs de lueur colorée en arrière-plan */
.bg-glow {
    position: absolute;
    width: 600px;
    height: 600px;
    border-radius: 50%;
    filter: blur(140px);
    opacity: 0.12;
    z-index: -1;
    pointer-events: none;
    transition: opacity 0.3s ease;
}

[data-theme="light"] .bg-glow {
    opacity: 0.04;
}

.glow-1 {
    top: -10%;
    left: -15%;
    background: var(--color-primary);
}
.glow-2 {
    top: 35%;
    right: -15%;
    background: var(--color-secondary);
}

/* --- 3. Structure & Layouts --- */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 1.5rem;
}

section {
    padding: 4.5rem 0;
}

.section-alt {
    background-color: var(--bg-alt);
    border-top: 1px solid var(--border-color);
    border-bottom: 1px solid var(--border-color);
    transition: background-color 0.3s ease, border-color 0.3s ease;
}

.grid-2 {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 3rem;
    align-items: center;
}

.grid-3 {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 2rem;
}

@media (max-width: 900px) {
    .grid-2, .grid-3 {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
}

/* --- 4. En-tête & Navigation --- */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    background: rgba(11, 15, 25, 0.8);
    backdrop-filter: var(--glass-blur);
    border-bottom: 1px solid var(--border-color);
    transition: background-color 0.3s ease, border-color 0.3s ease;
}

[data-theme="light"] .header {
    background: rgba(255, 255, 255, 0.85);
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 6.5rem;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.65rem;
    font-family: 'Outfit', sans-serif;
    font-size: 1.45rem;
    font-weight: 800;
    color: var(--text-primary);
    text-decoration: none;
    letter-spacing: -0.02em;
}

.logo svg, .logo img {
    width: 5.2rem;
    height: 5.2rem;
    object-fit: contain;
}

.nav {
    display: flex;
    align-items: center;
    gap: 1.75rem;
}

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 600;
    font-size: 0.95rem;
    transition: color 0.2s ease;
}

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

/* --- 5. Sélecteur de Thème --- */
.theme-toggle-wrapper {
    position: relative;
}

.theme-btn {
    background: rgba(255, 255, 255, 0.04);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    width: 2.25rem;
    height: 2.25rem;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1rem;
    transition: all 0.2s ease;
}

[data-theme="light"] .theme-btn {
    background: rgba(15, 23, 42, 0.04);
}

.theme-btn:hover {
    background: rgba(255, 255, 255, 0.08);
    border-color: var(--text-secondary);
}

.theme-dropdown {
    position: absolute;
    top: 2.75rem;
    right: 0;
    background: var(--bg-main);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    padding: 0.4rem;
    min-width: 8rem;
    box-shadow: var(--shadow-premium);
    display: none;
    flex-direction: column;
    gap: 0.2rem;
    z-index: 1001;
    backdrop-filter: var(--glass-blur);
}

.theme-dropdown.open {
    display: flex;
}

.theme-opt {
    background: none;
    border: none;
    color: var(--text-secondary);
    padding: 0.5rem 0.75rem;
    font-family: var(--font-body);
    font-size: 0.85rem;
    font-weight: 500;
    text-align: left;
    border-radius: 6px;
    cursor: pointer;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    transition: all 0.2s ease;
    width: 100%;
}

.theme-opt:hover, .theme-opt.active {
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.05);
}

[data-theme="light"] .theme-opt:hover, [data-theme="light"] .theme-opt.active {
    background: rgba(15, 23, 42, 0.04);
}

.menu-btn {
    display: none;
    flex-direction: column;
    justify-content: space-between;
    width: 1.65rem;
    height: 1.25rem;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0;
    z-index: 1001;
}

.hamburger-line {
    display: block;
    width: 100%;
    height: 2px;
    background-color: var(--text-primary);
    transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1), opacity 0.3s ease;
    border-radius: 2px;
}

.menu-btn.open .hamburger-line:nth-child(1) {
    transform: translateY(8px) rotate(45deg);
}

.menu-btn.open .hamburger-line:nth-child(2) {
    opacity: 0;
}

.menu-btn.open .hamburger-line:nth-child(3) {
    transform: translateY(-8px) rotate(-45deg);
}

/* --- 6. Boutons Premium --- */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    border-radius: 8px;
    font-weight: 700;
    font-size: 0.92rem;
    text-decoration: none;
    cursor: pointer;
    transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
    border: none;
}

.btn-primary {
    background: linear-gradient(135deg, var(--color-primary), var(--color-primary-hover));
    color: #fff !important;
    box-shadow: var(--shadow-glow);
}

.btn-primary:hover {
    transform: translateY(-1px);
    box-shadow: 0 8px 20px -5px rgba(5, 150, 105, 0.4);
}

.btn-secondary {
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
}

[data-theme="light"] .btn-secondary {
    background: rgba(15, 23, 42, 0.02);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.08);
    border-color: var(--text-secondary);
    transform: translateY(-1px);
}

/* --- 7. Hero Section --- */
.hero {
    position: relative;
    padding-top: 10.5rem;
    padding-bottom: 5.5rem;
    text-align: center;
}

.hero-tagline {
    display: inline-block;
    font-family: 'Outfit', sans-serif;
    font-size: 0.82rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.12em;
    color: var(--color-primary);
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    margin-bottom: 1.5rem;
    padding: 0.4rem 1rem;
    border-radius: 30px;
    border: 1px solid rgba(5, 150, 105, 0.2);
    background-color: rgba(5, 150, 105, 0.06);
    box-shadow: 0 4px 12px rgba(5, 150, 105, 0.05);
}

.txt-rotate {
    color: var(--color-primary);
    background: linear-gradient(135deg, var(--color-primary), var(--color-secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    border-bottom: 2px solid var(--color-primary);
    padding-bottom: 2px;
}

.hero h1 {
    font-family: 'Outfit', sans-serif;
    font-size: 3.5rem;
    font-weight: 800;
    line-height: 1.15;
    margin-bottom: 1.25rem;
    letter-spacing: -0.03em;
    background: linear-gradient(135deg, #ffffff 40%, #94a3b8);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

[data-theme="light"] .hero h1 {
    background: linear-gradient(135deg, #0f172a 40%, #475569);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero p {
    font-size: 1.2rem;
    color: var(--text-secondary);
    max-width: 720px;
    margin: 0 auto 2.5rem;
    line-height: 1.6;
}

.hero-ctas {
    display: flex;
    justify-content: center;
    gap: 1rem;
    margin-bottom: 3.5rem;
}

.showcase-container {
    position: relative;
    max-width: 900px;
    margin: 0 auto;
    border-radius: 16px;
    border: 1px solid var(--border-color);
    background: var(--bg-surface);
    box-shadow: var(--shadow-premium);
    overflow: hidden;
    backdrop-filter: var(--glass-blur);
    aspect-ratio: 16/9;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: border-color 0.3s ease;
}

.showcase-container:hover {
    border-color: var(--border-hover);
}

.showcase-placeholder {
    color: var(--text-secondary);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
    font-size: 1.1rem;
    font-weight: 600;
}

.showcase-placeholder i {
    font-size: 3.25rem;
    color: var(--color-primary);
}

/* --- 8. Section Titres & Cartes Premium --- */
.section-title-wrapper {
    text-align: center;
    margin-bottom: 3.5rem;
}

.section-title {
    font-family: 'Outfit', sans-serif;
    font-size: 2.25rem;
    font-weight: 800;
    margin-bottom: 1rem;
    letter-spacing: -0.02em;
}

.section-subtitle {
    color: var(--text-secondary);
    font-size: 1.1rem;
    max-width: 600px;
    margin: 0 auto;
    line-height: 1.5;
}

.card {
    background: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 2.5rem 2rem;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    backdrop-filter: var(--glass-blur);
    position: relative;
    box-shadow: var(--shadow-premium);
}

.card:hover {
    background: var(--bg-surface-hover);
    border-color: var(--border-hover);
    transform: translateY(-4px);
}

.card-icon {
    width: 3.5rem;
    height: 3.5rem;
    border-radius: 10px;
    background: rgba(5, 150, 105, 0.08);
    color: var(--color-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
    transition: all 0.3s ease;
}

.card:hover .card-icon {
    background: var(--color-primary);
    color: #fff;
    box-shadow: var(--shadow-glow);
}

.card h3 {
    font-family: 'Outfit', sans-serif;
    font-size: 1.3rem;
    font-weight: 700;
    margin-bottom: 0.75rem;
    letter-spacing: -0.01em;
}

.card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.5;
}

/* --- 9. Checklists de Fonctionnalités (Richesse SEO) --- */
.seo-benefit-section {
    padding: 4.5rem 0;
}

.benefit-list {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 1rem;
    margin-top: 1.5rem;
}

.benefit-item {
    display: flex;
    align-items: flex-start;
    gap: 0.75rem;
    font-size: 0.98rem;
    color: var(--text-secondary);
}

.benefit-item i {
    color: var(--color-primary);
    font-size: 1.1rem;
    margin-top: 0.2rem;
}

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

/* --- 10. Mairies Partenaires --- */
.partners-box {
    background: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    padding: 3.5rem 2.5rem;
    backdrop-filter: var(--glass-blur);
    text-align: center;
    box-shadow: var(--shadow-premium);
}

.partners-list {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 1.25rem;
    margin-top: 2.5rem;
}

.partner-tag {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background: rgba(255, 255, 255, 0.03);
    border: 1px solid var(--border-color);
    border-radius: 30px;
    padding: 0.75rem 1.5rem;
    font-weight: 700;
    color: var(--text-primary);
    font-size: 0.9rem;
    transition: all 0.2s ease;
}

[data-theme="light"] .partner-tag {
    background: #ffffff;
}

.partner-tag:hover {
    border-color: var(--color-primary);
    transform: translateY(-2px);
    box-shadow: 0 8px 16px -8px rgba(5, 150, 105, 0.3);
}

.partner-tag i {
    color: var(--color-primary);
}

/* --- 11. FAQ Section (Très important pour le SEO Google) --- */
.faq-grid {
    max-width: 800px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.faq-item {
    background: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1.75rem;
    box-shadow: var(--shadow-premium);
}

.faq-item h4 {
    font-family: 'Outfit', sans-serif;
    font-size: 1.15rem;
    font-weight: 700;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
}

.faq-item p {
    font-size: 0.95rem;
    color: var(--text-secondary);
    line-height: 1.5;
}

/* --- 12. Formulaire de Contact --- */
.form-container {
    max-width: 600px;
    margin: 0 auto;
    background: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    padding: 3rem 2.5rem;
    backdrop-filter: var(--glass-blur);
    box-shadow: var(--shadow-premium);
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    font-size: 0.9rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
    color: var(--text-primary);
}

.form-input {
    width: 100%;
    background: rgba(15, 23, 42, 0.35);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 0.8rem 1rem;
    color: var(--text-primary);
    font-family: var(--font-body);
    font-size: 0.95rem;
    transition: all 0.2s ease;
    outline: none;
}

[data-theme="light"] .form-input {
    background: #ffffff;
}

.form-input:focus {
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(5, 150, 105, 0.15);
}

.form-checkbox-wrapper {
    display: flex;
    align-items: flex-start;
    gap: 0.65rem;
    margin-bottom: 2rem;
}

.form-checkbox {
    width: 18px;
    height: 18px;
    accent-color: var(--color-primary);
    margin-top: 0.15rem;
    cursor: pointer;
    flex-shrink: 0;
}

.form-checkbox-label {
    font-size: 0.85rem;
    color: var(--text-secondary);
    line-height: 1.45;
    cursor: pointer;
}

/* --- 13. Footer --- */
.footer {
    background: #060910;
    border-top: 1px solid var(--border-color);
    padding: 4rem 0 2rem;
    color: var(--text-secondary);
    font-size: 0.9rem;
    transition: background-color 0.3s ease;
}

[data-theme="light"] .footer {
    background: #f1f5f9;
}

.footer-grid {
    display: grid;
    grid-template-columns: 2fr repeat(3, 1fr);
    gap: 3rem;
    margin-bottom: 3rem;
}

@media (max-width: 900px) {
    .footer-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
}

.footer-col h4 {
    font-family: 'Outfit', sans-serif;
    color: var(--text-primary);
    margin-bottom: 1.2rem;
    font-size: 1rem;
    font-weight: 700;
}

.footer-links {
    list-style: none;
}

.footer-links li {
    margin-bottom: 0.8rem;
}

.footer-links a {
    color: var(--text-secondary);
    text-decoration: none;
    transition: color 0.2s ease;
}

.footer-links a:hover {
    color: var(--text-primary);
}

.footer-bottom {
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-top: 1px solid var(--border-color);
    padding-top: 2rem;
    font-size: 0.82rem;
    flex-wrap: wrap;
    gap: 1rem;
}

/* --- 14. Pages Secondaires (CGU, RGPD) --- */
.text-page {
    padding-top: 10.5rem;
    padding-bottom: 5.5rem;
    max-width: 800px;
    margin: 0 auto;
}

.text-page h1 {
    font-family: 'Outfit', sans-serif;
    font-size: 2.75rem;
    font-weight: 800;
    margin-bottom: 1.5rem;
    letter-spacing: -0.02em;
}

.text-page h2 {
    font-family: 'Outfit', sans-serif;
    font-size: 1.5rem;
    font-weight: 700;
    margin-top: 2.5rem;
    margin-bottom: 1rem;
    letter-spacing: -0.01em;
}

.text-page p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    line-height: 1.65;
    font-size: 0.98rem;
}

.text-page ul {
    margin-left: 1.5rem;
    margin-bottom: 1.5rem;
    color: var(--text-secondary);
}

.text-page li {
    margin-bottom: 0.5rem;
    font-size: 0.98rem;
}

/* --- 15. Responsive Mobile Menu --- */
@media (max-width: 768px) {
    .menu-btn {
        display: flex !important;
    }
    
    .nav {
        position: fixed;
        top: 6.5rem;
        left: 0;
        width: 100%;
        height: 0;
        overflow: hidden;
        background: var(--bg-main);
        flex-direction: column;
        align-items: center;
        gap: 1.75rem;
        padding: 0;
        border-bottom: none;
        transition: height 0.3s ease, padding 0.3s ease;
    }
    
    .nav.open {
        height: calc(100vh - 6.5rem);
        padding: 3rem 0;
        border-bottom: 1px solid var(--border-color);
    }
    
    .hero h1 {
        font-size: 2.5rem;
    }
    
    /* Calibration responsive pour éviter les débordements horizontaux */
    .hero-ctas {
        flex-direction: column;
        align-items: center;
        gap: 0.75rem;
    }
    
    .hero-ctas .btn {
        width: 100%;
        max-width: 280px;
    }
    
    .logo span {
        font-size: 1.25rem;
    }
    
    .solutions-intro h1 {
        font-size: 2.2rem;
    }
}

/* --- 16. Classes Spécifiques pour la page Solutions --- */
.solutions-intro {
    text-align: center;
    padding-bottom: 2.5rem;
}

.solutions-intro h1 {
    font-family: 'Outfit', sans-serif;
    font-size: 3rem;
    font-weight: 800;
    margin-bottom: 1.25rem;
}

.solutions-intro p {
    color: var(--text-secondary);
    font-size: 1.2rem;
    max-width: 800px;
    margin: 0 auto;
}

.grid-asymmetric {
    display: grid;
    grid-template-columns: 1.2fr 1.8fr;
    gap: 4rem;
    align-items: center;
}

.grid-subcards {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1.5rem;
}

.icon-purple {
    background: rgba(139, 92, 246, 0.08) !important;
    color: #8b5cf6 !important;
}

.icon-purple-hover:hover .card-icon {
    background: #8b5cf6 !important;
    color: #fff !important;
    box-shadow: 0 0 25px rgba(139, 92, 246, 0.25) !important;
}

.icon-teal-hover:hover .card-icon {
    background: var(--color-secondary) !important;
    color: #fff !important;
    box-shadow: 0 0 25px rgba(13, 148, 136, 0.25) !important;
}

@media (max-width: 900px) {
    .grid-asymmetric {
        grid-template-columns: 1fr;
        gap: 2.5rem;
    }
    
    .grid-subcards {
        grid-template-columns: 1fr;
    }
}

/* Page Contact Layout */
.contact-grid {
    display: grid;
    grid-template-columns: 1.2fr 1.8fr;
    gap: 4rem;
    align-items: start;
}

.contact-info-card {
    background: var(--bg-surface);
    border: 1px solid var(--border-color);
    border-radius: 20px;
    padding: 2.5rem;
    backdrop-filter: var(--glass-blur);
    box-shadow: var(--shadow-premium);
    transition: background-color 0.3s ease, border-color 0.3s ease;
}

@media (max-width: 900px) {
    .contact-grid {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .form-container, .contact-info-card {
        padding: 2rem 1.5rem;
    }
}

/* Scroll Reveal Animations */
.reveal {
    opacity: 0;
    transform: translateY(20px);
    transition: opacity 0.8s cubic-bezier(0.16, 1, 0.3, 1), transform 0.8s cubic-bezier(0.16, 1, 0.3, 1);
}

.reveal.visible {
    opacity: 1;
    transform: translateY(0);
}

/* Scroll Down & Back to Top indicators */
.scroll-down-wrapper {
    margin-top: 3.5rem;
    display: flex;
    justify-content: center;
    align-items: center;
}

.scroll-down-btn {
    display: flex;
    justify-content: center;
    align-items: center;
    width: 2.6rem;
    height: 2.6rem;
    border-radius: 50%;
    border: 1px solid var(--border-color);
    background: rgba(255, 255, 255, 0.03);
    color: var(--text-secondary);
    transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
    cursor: pointer;
}

[data-theme="light"] .scroll-down-btn {
    background: rgba(15, 23, 42, 0.02);
}

.scroll-down-btn:hover {
    color: var(--color-primary);
    border-color: var(--color-primary);
    transform: translateY(3px);
    box-shadow: 0 4px 12px rgba(5, 150, 105, 0.1);
}

.scroll-arrow {
    display: block;
    width: 8px;
    height: 8px;
    border-bottom: 2px solid currentColor;
    border-right: 2px solid currentColor;
    transform: translateY(-2px) rotate(45deg);
    animation: bounce 2s infinite ease-in-out;
}

@keyframes bounce {
    0%, 20%, 50%, 80%, 100% {
        transform: translateY(-2px) rotate(45deg);
    }
    40% {
        transform: translateY(4px) rotate(45deg);
    }
    60% {
        transform: translateY(1px) rotate(45deg);
    }
}

.back-to-top {
    position: fixed;
    bottom: 2rem;
    right: 2rem;
    width: 3rem;
    height: 3rem;
    border-radius: 50%;
    border: 1px solid var(--border-color);
    background: var(--bg-surface);
    color: var(--text-primary);
    display: flex;
    justify-content: center;
    align-items: center;
    cursor: pointer;
    z-index: 999;
    opacity: 0;
    visibility: hidden;
    transform: translateY(15px);
    transition: opacity 0.3s ease, transform 0.3s ease, visibility 0.3s ease, background-color 0.3s ease, border-color 0.3s ease;
    box-shadow: var(--shadow-premium);
    backdrop-filter: var(--glass-blur);
}

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

.back-to-top:hover {
    color: var(--color-primary);
    border-color: var(--color-primary);
    transform: translateY(-3px);
    box-shadow: 0 8px 20px -5px rgba(5, 150, 105, 0.25);
}

.back-arrow {
    display: block;
    width: 8px;
    height: 8px;
    border-top: 2px solid currentColor;
    border-left: 2px solid currentColor;
    transform: translateY(2px) rotate(45deg);
}

@media (max-width: 768px) {
    .back-to-top {
        bottom: 1.5rem;
        right: 1.5rem;
        width: 2.75rem;
        height: 2.75rem;
    }
}