:root {
    --primary-color: #2563eb;
    --primary-dark: #1e40af;
    --primary-light: #3b82f6;
    --secondary-color: #64748b;
    --accent-color: #f59e0b;
    --success-color: #10b981;
    --danger-color: #ef4444;
    --dark-bg: #0f172a;
    --light-bg: #f8fafc;
    --text-dark: #1e293b;
    --text-light: #64748b;
    --border-color: #e2e8f0;
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: var(--text-dark);
    overflow-x: hidden;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Navbar */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    background: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    box-shadow: var(--shadow-sm);
    z-index: 1000;
    transition: all 0.3s ease;
}

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

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 20px;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 12px;
    font-weight: 700;
    font-size: 1.25rem;
    color: var(--primary-color);
}

.logo {
    width: 40px;
    height: 40px;
}

.nav-menu {
    display: flex;
    gap: 2rem;
    align-items: center;
}

.nav-link {
    color: var(--text-dark);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.3s ease;
    position: relative;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 0;
    height: 2px;
    background: var(--primary-color);
    transition: width 0.3s ease;
}

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

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

.menu-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
}

.menu-toggle span {
    width: 25px;
    height: 3px;
    background: var(--text-dark);
    transition: all 0.3s ease;
}

/* Hero Section */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    overflow: hidden;
    padding-top: 80px;
}

.hero-background {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: 
        radial-gradient(circle at 20% 50%, rgba(255, 255, 255, 0.1) 0%, transparent 50%),
        radial-gradient(circle at 80% 80%, rgba(255, 255, 255, 0.1) 0%, transparent 50%);
}

.hero-background::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 100%;
    max-width: 1400px;
    height: 70%;
    background-image: url('../images/baustelle-illustration.svg');
    background-repeat: no-repeat;
    background-position: center bottom;
    background-size: contain;
    opacity: 0.35;
    pointer-events: none;
    z-index: 0;
}

@keyframes pulse {
    0%, 100% { opacity: 1; }
    50% { opacity: 0.5; }
}

.hero-content {
    position: relative;
    text-align: center;
    color: white;
    z-index: 1;
}

.hero-title {
    font-size: clamp(2.5rem, 5vw, 4rem);
    font-weight: 800;
    margin-bottom: 1rem;
    line-height: 1.2;
    text-shadow: 0 2px 10px rgba(0, 0, 0, 0.2);
}

.hero-subtitle {
    font-size: clamp(1.125rem, 2vw, 1.5rem);
    font-weight: 400;
    margin-bottom: 2rem;
    opacity: 0.95;
    max-width: 900px;
    margin-left: auto;
    margin-right: auto;
    line-height: 1.7;
}

.hero-features {
    display: flex;
    justify-content: center;
    gap: 2rem;
    flex-wrap: wrap;
    margin-bottom: 3rem;
}

.hero-feature {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.hero-feature svg {
    width: 24px;
    height: 24px;
}

.hero-cta {
    display: flex;
    justify-content: center;
    gap: 1rem;
    flex-wrap: wrap;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    font-weight: 600;
    text-decoration: none;
    border: none;
    border-radius: 0.5rem;
    cursor: pointer;
    transition: all 0.3s ease;
    text-align: center;
    justify-content: center;
}

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

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

.btn-secondary {
    background: rgba(255, 255, 255, 0.2);
    color: white;
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.3);
}

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.3);
    transform: translateY(-2px);
}

.btn-large {
    padding: 1rem 2rem;
    font-size: 1.125rem;
}

.btn-download svg {
    width: 20px;
    height: 20px;
}

/* Sections */
.section {
    padding: 5rem 0;
}

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

.section-dark {
    background: var(--dark-bg);
    color: white;
}

.section-header {
    text-align: center;
    margin-bottom: 4rem;
}

.section-header h2 {
    font-size: clamp(2rem, 4vw, 3rem);
    font-weight: 800;
    margin-bottom: 1rem;
}

.section-header p {
    font-size: 1.25rem;
    color: var(--text-light);
}

.section-dark .section-header p {
    color: rgba(255, 255, 255, 0.7);
}

/* Features Grid */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.feature-card {
    background: white;
    padding: 2rem;
    border-radius: 1rem;
    box-shadow: var(--shadow-md);
    transition: all 0.3s ease;
}

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

.feature-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, var(--primary-color), var(--primary-light));
    border-radius: 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
}

.feature-icon svg {
    width: 30px;
    height: 30px;
    color: white;
}

.feature-card h3 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--text-dark);
}

.feature-card p {
    color: var(--text-light);
    line-height: 1.8;
}

/* Download Grid */
.download-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
    margin-bottom: 3rem;
}

.download-card {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    padding: 2.5rem;
    border-radius: 1rem;
    transition: all 0.3s ease;
    text-align: center;
}

.download-card:hover {
    transform: translateY(-5px);
    background: rgba(255, 255, 255, 0.15);
    border-color: rgba(255, 255, 255, 0.3);
}

.download-icon {
    width: 80px;
    height: 80px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 1rem;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 1.5rem;
}

.download-icon svg {
    width: 40px;
    height: 40px;
    color: white;
}

.download-card h3 {
    font-size: 1.75rem;
    font-weight: 700;
    margin-bottom: 0.5rem;
}

.download-version {
    color: rgba(255, 255, 255, 0.7);
    margin-bottom: 1.5rem;
}

.download-features {
    list-style: none;
    margin-bottom: 2rem;
    text-align: left;
}

.download-features li {
    padding: 0.5rem 0;
    position: relative;
    padding-left: 1.5rem;
}

.download-features li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--success-color);
    font-weight: 700;
}

.download-size {
    margin-top: 1rem;
    font-size: 0.875rem;
    color: rgba(255, 255, 255, 0.6);
}

.download-info {
    max-width: 800px;
    margin: 0 auto;
}

.info-box {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    padding: 2rem;
    border-radius: 1rem;
    display: flex;
    gap: 1.5rem;
}

.info-box svg {
    width: 40px;
    height: 40px;
    flex-shrink: 0;
    color: var(--accent-color);
}

.info-box h4 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
}

.info-box ul {
    list-style: none;
}

.info-box ul li {
    padding: 0.25rem 0;
}

/* Documentation */
.docs-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
}

.doc-card {
    background: white;
    padding: 2rem;
    border-radius: 1rem;
    box-shadow: var(--shadow-md);
}

.doc-card h3 {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: 1rem;
    color: var(--primary-color);
}

.doc-card p, .doc-card ul, .doc-card ol {
    color: var(--text-light);
    line-height: 1.8;
}

.doc-card ul, .doc-card ol {
    margin-left: 1.5rem;
}

.doc-card li {
    margin-bottom: 0.5rem;
}

.doc-card strong {
    color: var(--text-dark);
    font-weight: 600;
}

/* Footer */
.footer {
    background: var(--dark-bg);
    color: white;
    padding: 4rem 0 2rem;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 3rem;
    margin-bottom: 3rem;
}

.footer-section h4 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

.footer-section p {
    color: rgba(255, 255, 255, 0.7);
    margin-bottom: 0.5rem;
}

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

.footer-section ul li {
    margin-bottom: 0.5rem;
}

.footer-section a {
    color: rgba(255, 255, 255, 0.7);
    text-decoration: none;
    transition: color 0.3s ease;
}

.footer-section a:hover {
    color: white;
}

.footer-version {
    font-size: 0.875rem;
    color: rgba(255, 255, 255, 0.5);
}

.footer-bottom {
    border-top: 1px solid rgba(255, 255, 255, 0.1);
    padding-top: 2rem;
    text-align: center;
    color: rgba(255, 255, 255, 0.5);
}

/* Modal */
.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.75);
    z-index: 2000;
    padding: 20px;
    overflow-y: auto;
}

.modal.active {
    display: flex;
    align-items: center;
    justify-content: center;
}

.modal-content {
    background: white;
    border-radius: 1rem;
    max-width: 800px;
    width: 100%;
    max-height: 90vh;
    display: flex;
    flex-direction: column;
    box-shadow: var(--shadow-xl);
}

.modal-header {
    padding: 2rem 2rem 1rem;
    border-bottom: 1px solid var(--border-color);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-header h2 {
    font-size: 1.75rem;
    font-weight: 700;
    color: var(--text-dark);
}

.modal-close {
    background: none;
    border: none;
    font-size: 2rem;
    color: var(--text-light);
    cursor: pointer;
    padding: 0;
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    border-radius: 0.5rem;
    transition: all 0.3s ease;
}

.modal-close:hover {
    background: var(--light-bg);
    color: var(--text-dark);
}

.modal-body {
    padding: 2rem;
    overflow-y: auto;
    flex: 1;
}

.license-content h3 {
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--text-dark);
    margin-top: 1.5rem;
    margin-bottom: 0.75rem;
}

.license-content h3:first-child {
    margin-top: 0;
}

.license-content p {
    color: var(--text-light);
    line-height: 1.8;
    margin-bottom: 1rem;
}

.license-content ul {
    margin-left: 1.5rem;
    margin-bottom: 1rem;
}

.license-content li {
    color: var(--text-light);
    line-height: 1.8;
    margin-bottom: 0.5rem;
}

.license-content a {
    color: var(--primary-color);
    text-decoration: none;
}

.license-content a:hover {
    text-decoration: underline;
}

.license-acceptance {
    margin-top: 2rem;
    padding: 1.5rem;
    background: var(--light-bg);
    border-radius: 0.5rem;
}

.checkbox-container {
    display: flex;
    align-items: flex-start;
    gap: 1rem;
    cursor: pointer;
    user-select: none;
}

.checkbox-container input[type="checkbox"] {
    width: 24px;
    height: 24px;
    cursor: pointer;
    flex-shrink: 0;
}

.checkbox-label {
    color: var(--text-dark);
    line-height: 1.6;
    font-weight: 500;
}

.modal-footer {
    padding: 1.5rem 2rem;
    border-top: 1px solid var(--border-color);
    display: flex;
    justify-content: flex-end;
    gap: 1rem;
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

/* Responsive */
@media (max-width: 768px) {
    .nav-menu {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: 1rem;
        box-shadow: var(--shadow-md);
        gap: 1rem;
    }

    .nav-menu.active {
        display: flex;
    }

    .menu-toggle {
        display: flex;
    }

    .menu-toggle.active span:nth-child(1) {
        transform: rotate(45deg) translate(5px, 5px);
    }

    .menu-toggle.active span:nth-child(2) {
        opacity: 0;
    }

    .menu-toggle.active span:nth-child(3) {
        transform: rotate(-45deg) translate(7px, -6px);
    }

    .hero-features {
        flex-direction: column;
        align-items: center;
        gap: 1rem;
    }

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

    .btn-large {
        width: 100%;
    }

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

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

    .info-box {
        flex-direction: column;
    }

    .modal-content {
        margin: 20px;
    }
}

/* Performance optimizations */
* {
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

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

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in {
    animation: fadeIn 0.6s ease-out;
}