/**
 * Dosya: main.css | Yol: /home/main/public_html/license.zefre.net/hali-satis/assets/css/main.css
 * Geliştiren: Muhsin İŞSEVER
 * E-posta: muhsin.issever@gmail.com
 * Web sitesi: https://works.zefre.net/
 * Zefre.NET Internet Technologies
 * Dosya Oluşturma Tarihi: 2025-12-05
 * Dosya Güncelleme Tarihi: 2025-12-05 - İlk oluşturma
 * Lisans: MIT License
 */

/* ========================================
   RESET & BASE STYLES
======================================== */

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

:root {
    /* Primary Colors */
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;

    /* Secondary Colors */
    --secondary: #ec4899;
    --secondary-dark: #db2777;

    /* Neutral Colors */
    --dark: #0f172a;
    --dark-light: #1e293b;
    --gray: #64748b;
    --gray-light: #cbd5e1;
    --light: #f8fafc;
    --white: #ffffff;

    /* Gradient */
    --gradient: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    --gradient-reverse: linear-gradient(135deg, var(--secondary) 0%, var(--primary) 100%);

    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 25px 50px -12px rgba(0, 0, 0, 0.25);

    /* Typography */
    --font-primary: 'Inter', sans-serif;
    --font-display: 'Playfair Display', serif;

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;

    /* Border Radius */
    --radius-sm: 0.375rem;
    --radius: 0.5rem;
    --radius-md: 0.75rem;
    --radius-lg: 1rem;
    --radius-xl: 1.5rem;
    --radius-2xl: 2rem;

    /* Transitions */
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    --transition-slow: all 0.5s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: var(--font-primary);
    color: var(--dark);
    background: var(--white);
    line-height: 1.6;
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.container {
    max-width: 1280px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

/* ========================================
   PRELOADER
======================================== */

#preloader {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--dark);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    z-index: 9999;
    transition: opacity 0.5s ease, visibility 0.5s ease;
}

#preloader.fade-out {
    opacity: 0;
    visibility: hidden;
}

.spinner {
    width: 60px;
    height: 60px;
    border: 4px solid rgba(255, 255, 255, 0.1);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 0.8s linear infinite;
}

#preloader p {
    color: var(--white);
    margin-top: var(--spacing-md);
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 2px;
}

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

/* ========================================
   NAVIGATION
======================================== */

.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-sm);
    z-index: 1000;
    transition: var(--transition);
}

.navbar.scrolled {
    box-shadow: var(--shadow);
}

.navbar .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding-top: var(--spacing-sm);
    padding-bottom: var(--spacing-sm);
}

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

.nav-brand .logo {
    height: 40px;
    width: auto;
}

.brand-text {
    font-weight: 700;
    font-size: 1.25rem;
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

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

.nav-link {
    color: var(--dark);
    text-decoration: none;
    font-weight: 500;
    font-size: 0.9375rem;
    transition: var(--transition);
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--gradient);
    transition: var(--transition);
}

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

.nav-link.cta-btn {
    background: var(--gradient);
    color: var(--white);
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-lg);
}

.nav-link.cta-btn::after {
    display: none;
}

.nav-link.cta-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.mobile-menu-toggle {
    display: none;
    font-size: 1.5rem;
    color: var(--dark);
    cursor: pointer;
}

/* ========================================
   HERO SECTION
======================================== */

.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: 80px;
    overflow: hidden;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: -1;
}

.gradient-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg,
        rgba(99, 102, 241, 0.05) 0%,
        rgba(236, 72, 153, 0.05) 100%);
}

.animated-shapes {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
}

.shape {
    position: absolute;
    border-radius: 50%;
    filter: blur(60px);
    opacity: 0.3;
    animation: float 20s ease-in-out infinite;
}

.shape-1 {
    width: 400px;
    height: 400px;
    background: var(--primary);
    top: 10%;
    left: 10%;
    animation-delay: 0s;
}

.shape-2 {
    width: 300px;
    height: 300px;
    background: var(--secondary);
    top: 50%;
    right: 10%;
    animation-delay: 5s;
}

.shape-3 {
    width: 250px;
    height: 250px;
    background: var(--primary);
    bottom: 10%;
    left: 50%;
    animation-delay: 10s;
}

@keyframes float {
    0%, 100% { transform: translate(0, 0); }
    25% { transform: translate(30px, -30px); }
    50% { transform: translate(-20px, 20px); }
    75% { transform: translate(20px, 30px); }
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-2xl);
    align-items: center;
}

.hero-text {
    animation: fadeInUp 1s ease;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.badge {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    background: rgba(99, 102, 241, 0.1);
    color: var(--primary);
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-2xl);
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: var(--spacing-md);
}

.hero-title {
    font-family: var(--font-display);
    font-size: 4rem;
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: var(--spacing-md);
    color: var(--dark);
}

.gradient-text {
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-description {
    font-size: 1.125rem;
    color: var(--gray);
    margin-bottom: var(--spacing-xl);
    line-height: 1.8;
}

.hero-description .highlight {
    color: var(--primary);
    font-weight: 600;
}

.hero-stats {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-xl);
}

.stat {
    text-align: center;
    padding: var(--spacing-md);
    background: var(--white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.stat:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.stat-number {
    font-size: 2.5rem;
    font-weight: 800;
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--spacing-xs);
}

.stat-number::after {
    content: '+';
}

.stat-label {
    font-size: 0.875rem;
    color: var(--gray);
    font-weight: 500;
}

.hero-actions {
    display: flex;
    gap: var(--spacing-md);
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    padding: var(--spacing-md) var(--spacing-lg);
    border-radius: var(--radius-lg);
    font-weight: 600;
    text-decoration: none;
    transition: var(--transition);
    cursor: pointer;
    border: none;
    font-family: inherit;
    font-size: 1rem;
}

.btn-primary {
    background: var(--gradient);
    color: var(--white);
    box-shadow: var(--shadow-md);
}

.btn-primary:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.btn-outline {
    background: transparent;
    color: var(--dark);
    border: 2px solid var(--gray-light);
}

.btn-outline:hover {
    border-color: var(--primary);
    color: var(--primary);
    transform: translateY(-3px);
}

.btn-large {
    padding: var(--spacing-md) var(--spacing-xl);
    font-size: 1.125rem;
}

.hero-image {
    position: relative;
    animation: fadeInRight 1s ease 0.3s both;
}

@keyframes fadeInRight {
    from {
        opacity: 0;
        transform: translateX(30px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.mockup-container {
    position: relative;
    padding: var(--spacing-md);
    background: var(--white);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow-xl);
}

.mockup-screen {
    position: relative;
    border-radius: var(--radius-lg);
    overflow: hidden;
}

.mockup-screen img {
    width: 100%;
    height: auto;
    display: block;
}

.mockup-overlay {
    position: absolute;
    top: var(--spacing-md);
    right: var(--spacing-md);
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    background: rgba(0, 0, 0, 0.8);
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-2xl);
}

.pulse-dot {
    width: 10px;
    height: 10px;
    background: #10b981;
    border-radius: 50%;
    animation: pulse 2s ease infinite;
}

@keyframes pulse {
    0%, 100% {
        opacity: 1;
        transform: scale(1);
    }
    50% {
        opacity: 0.5;
        transform: scale(1.2);
    }
}

.live-badge {
    color: var(--white);
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.scroll-indicator {
    position: absolute;
    bottom: var(--spacing-xl);
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: var(--spacing-xs);
    animation: bounce 2s ease infinite;
}

@keyframes bounce {
    0%, 100% { transform: translateX(-50%) translateY(0); }
    50% { transform: translateX(-50%) translateY(-10px); }
}

.mouse {
    width: 24px;
    height: 40px;
    border: 2px solid var(--gray);
    border-radius: var(--radius-xl);
    position: relative;
}

.wheel {
    width: 3px;
    height: 8px;
    background: var(--gray);
    border-radius: 3px;
    position: absolute;
    top: 8px;
    left: 50%;
    transform: translateX(-50%);
    animation: scroll 2s ease infinite;
}

@keyframes scroll {
    0% { opacity: 1; top: 8px; }
    100% { opacity: 0; top: 20px; }
}

.scroll-indicator p {
    font-size: 0.75rem;
    color: var(--gray);
    text-transform: uppercase;
    letter-spacing: 1px;
}

/* ========================================
   SECTION HEADERS
======================================== */

.section-header {
    text-align: center;
    max-width: 700px;
    margin: 0 auto var(--spacing-2xl);
}

.section-badge {
    display: inline-block;
    background: rgba(99, 102, 241, 0.1);
    color: var(--primary);
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-2xl);
    font-size: 0.875rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: var(--spacing-md);
}

.section-title {
    font-family: var(--font-display);
    font-size: 3rem;
    font-weight: 800;
    line-height: 1.2;
    margin-bottom: var(--spacing-md);
}

.section-description {
    font-size: 1.125rem;
    color: var(--gray);
    line-height: 1.8;
}

/* ========================================
   FEATURES SECTION
======================================== */

.features {
    padding: var(--spacing-2xl) 0;
    background: var(--light);
}

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

.feature-card {
    background: var(--white);
    padding: var(--spacing-xl);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow);
    transition: var(--transition);
}

.feature-card:hover {
    transform: translateY(-10px);
    box-shadow: var(--shadow-xl);
}

.feature-icon {
    width: 70px;
    height: 70px;
    background: var(--gradient);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    color: var(--white);
    margin-bottom: var(--spacing-md);
}

.feature-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-sm);
    color: var(--dark);
}

.feature-description {
    color: var(--gray);
    margin-bottom: var(--spacing-md);
    line-height: 1.7;
}

.feature-list {
    list-style: none;
}

.feature-list li {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    color: var(--dark);
    margin-bottom: var(--spacing-xs);
    font-size: 0.9375rem;
}

.feature-list i {
    color: #10b981;
    font-size: 1rem;
}

/* ========================================
   TECH STACK SECTION
======================================== */

.tech-stack {
    padding: var(--spacing-2xl) 0;
}

.tech-grid {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    gap: var(--spacing-md);
}

.tech-card {
    background: var(--white);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
    text-align: center;
    transition: var(--transition);
}

.tech-card:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.tech-icon {
    font-size: 3rem;
    background: var(--gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
    margin-bottom: var(--spacing-sm);
}

.tech-card h4 {
    font-size: 1.125rem;
    font-weight: 700;
    margin-bottom: var(--spacing-xs);
    color: var(--dark);
}

.tech-card p {
    font-size: 0.875rem;
    color: var(--gray);
}

/* ========================================
   DEMO SECTION
======================================== */

.demo-section {
    padding: var(--spacing-2xl) 0;
    background: var(--light);
}

.demo-content {
    max-width: 900px;
    margin: 0 auto;
}

.demo-links {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-xl);
}

.demo-link {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    background: var(--white);
    padding: var(--spacing-xl);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow);
    text-decoration: none;
    transition: var(--transition);
}

.demo-link:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-lg);
}

.demo-link-icon {
    width: 70px;
    height: 70px;
    background: var(--gradient);
    border-radius: var(--radius-lg);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2rem;
    color: var(--white);
    flex-shrink: 0;
}

.demo-link-content h4 {
    font-size: 1.5rem;
    font-weight: 700;
    color: var(--dark);
    margin-bottom: var(--spacing-xs);
}

.demo-link-content p {
    color: var(--gray);
    margin-bottom: var(--spacing-xs);
}

.demo-link-url {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    color: var(--primary);
    font-weight: 600;
    font-size: 0.9375rem;
}

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

.credentials-box {
    background: var(--white);
    padding: var(--spacing-xl);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow);
    max-width: 500px;
    margin: 0 auto;
}

.credentials-box i {
    font-size: 2.5rem;
    color: var(--primary);
    margin-bottom: var(--spacing-md);
}

.credentials-box h5 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    color: var(--dark);
}

.credential-item {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-sm) 0;
    border-bottom: 1px solid var(--gray-light);
}

.credential-item:last-child {
    border-bottom: none;
}

.credential-item .label {
    font-weight: 600;
    color: var(--dark);
}

.credential-item code {
    background: var(--light);
    padding: var(--spacing-xs) var(--spacing-sm);
    border-radius: var(--radius);
    font-family: 'Courier New', monospace;
    color: var(--primary);
    font-weight: 600;
}

/* ========================================
   PRICING SECTION
======================================== */

.pricing-section {
    padding: var(--spacing-2xl) 0;
}

.pricing-card {
    max-width: 600px;
    margin: 0 auto;
    background: var(--white);
    border-radius: var(--radius-2xl);
    box-shadow: var(--shadow-xl);
    overflow: hidden;
}

.pricing-header {
    background: var(--gradient);
    padding: var(--spacing-xl);
    text-align: center;
    color: var(--white);
}

.pricing-badge {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    background: rgba(255, 255, 255, 0.2);
    padding: var(--spacing-xs) var(--spacing-md);
    border-radius: var(--radius-2xl);
    font-size: 0.875rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: var(--spacing-md);
}

.pricing-title {
    font-size: 2rem;
    font-weight: 800;
    margin-bottom: var(--spacing-sm);
}

.pricing-price {
    font-size: 3rem;
    font-weight: 900;
    margin-bottom: var(--spacing-sm);
}

.pricing-description {
    font-size: 1rem;
    opacity: 0.9;
}

.pricing-features {
    padding: var(--spacing-xl);
}

.feature-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) 0;
    border-bottom: 1px solid var(--gray-light);
}

.feature-item:last-child {
    border-bottom: none;
}

.feature-item i {
    color: #10b981;
    font-size: 1.25rem;
}

.feature-item span {
    color: var(--dark);
    font-weight: 500;
}

.pricing-card .btn {
    margin: 0 var(--spacing-xl) var(--spacing-xl);
    width: calc(100% - (2 * var(--spacing-xl)));
    justify-content: center;
}

/* ========================================
   CONTACT SECTION
======================================== */

.contact-section {
    padding: var(--spacing-2xl) 0;
    background: var(--light);
}

.contact-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-2xl);
}

.contact-info {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.contact-item {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
    background: var(--white);
    padding: var(--spacing-md);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow);
}

.contact-icon {
    width: 50px;
    height: 50px;
    background: var(--gradient);
    border-radius: var(--radius);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.25rem;
    color: var(--white);
    flex-shrink: 0;
}

.contact-details h4 {
    font-size: 1.125rem;
    font-weight: 700;
    color: var(--dark);
    margin-bottom: 0.25rem;
}

.contact-details a {
    color: var(--primary);
    text-decoration: none;
    font-weight: 500;
    transition: var(--transition);
}

.contact-details a:hover {
    color: var(--primary-dark);
}

.contact-form-wrapper {
    background: var(--white);
    padding: var(--spacing-xl);
    border-radius: var(--radius-xl);
    box-shadow: var(--shadow);
}

.contact-form {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-md);
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.form-group label {
    font-weight: 600;
    color: var(--dark);
    font-size: 0.9375rem;
}

.form-group input,
.form-group textarea {
    padding: var(--spacing-sm) var(--spacing-md);
    border: 2px solid var(--gray-light);
    border-radius: var(--radius);
    font-family: inherit;
    font-size: 1rem;
    transition: var(--transition);
}

.form-group input:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary);
}

.form-group textarea {
    resize: vertical;
}

.contact-form .btn {
    margin-top: var(--spacing-sm);
}

/* ========================================
   FOOTER
======================================== */

.footer {
    background: var(--dark);
    color: var(--white);
    padding: var(--spacing-2xl) 0 var(--spacing-md);
}

.footer-content {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr;
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
}

.footer-brand .footer-logo {
    height: 50px;
    width: auto;
    margin-bottom: var(--spacing-md);
}

.footer-description {
    color: var(--gray-light);
    line-height: 1.8;
}

.footer-links h4,
.footer-contact h4 {
    font-size: 1.125rem;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
}

.footer-links ul,
.footer-contact ul {
    list-style: none;
}

.footer-links li,
.footer-contact li {
    margin-bottom: var(--spacing-xs);
}

.footer-links a,
.footer-contact a {
    color: var(--gray-light);
    text-decoration: none;
    transition: var(--transition);
}

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

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: var(--spacing-md);
    text-align: center;
    color: var(--gray-light);
    font-size: 0.875rem;
}

.footer-bottom p {
    margin-bottom: 0.5rem;
}

/* ========================================
   BACK TO TOP
======================================== */

.back-to-top {
    position: fixed;
    bottom: var(--spacing-lg);
    right: var(--spacing-lg);
    width: 50px;
    height: 50px;
    background: var(--gradient);
    color: var(--white);
    border: none;
    border-radius: 50%;
    font-size: 1.25rem;
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transition: var(--transition);
    box-shadow: var(--shadow-lg);
    z-index: 999;
}

.back-to-top.visible {
    opacity: 1;
    visibility: visible;
}

.back-to-top:hover {
    transform: translateY(-5px);
    box-shadow: var(--shadow-xl);
}

/* ========================================
   RESPONSIVE DESIGN
======================================== */

@media (max-width: 1024px) {
    .hero-content {
        grid-template-columns: 1fr;
        gap: var(--spacing-xl);
    }

    .hero-title {
        font-size: 3rem;
    }

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

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

    .contact-content {
        grid-template-columns: 1fr;
    }
}

@media (max-width: 768px) {
    .nav-menu {
        display: none;
    }

    .mobile-menu-toggle {
        display: block;
    }

    .hero-title {
        font-size: 2.5rem;
    }

    .section-title {
        font-size: 2rem;
    }

    .hero-stats {
        grid-template-columns: 1fr;
    }

    .features-grid {
        grid-template-columns: 1fr;
    }

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

    .demo-links {
        grid-template-columns: 1fr;
    }

    .footer-content {
        grid-template-columns: 1fr;
    }

    .hero-actions {
        flex-direction: column;
    }

    .btn {
        width: 100%;
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }

    .stat-number {
        font-size: 2rem;
    }

    .tech-grid {
        grid-template-columns: 1fr;
    }
}