/* Variables & Clean Colors */
:root {
    --bg-primary: #0b0f17;
    --bg-secondary: #121824;
    --bg-tertiary: #1b2436;
    --text-primary: #f3f4f6;
    --text-secondary: #9ca3af;
    --accent: #3b82f6;
    --accent-hover: #60a5fa;
    --accent-rgb: 59, 130, 246;
    --border-color: #1e293b;
    --shadow-color: rgba(0, 0, 0, 0.4);
    --navbar-bg: rgba(11, 15, 23, 0.9);
    --danger: #ef4444;
    --success: #10b981;
}

html.light {
    --bg-primary: #f8fafc;
    --bg-secondary: #ffffff;
    --bg-tertiary: #f1f5f9;
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --accent: #2563eb;
    --accent-hover: #1d4ed8;
    --accent-rgb: 37, 99, 235;
    --border-color: #e2e8f0;
    --shadow-color: rgba(0, 0, 0, 0.06);
    --navbar-bg: rgba(248, 250, 252, 0.9);
}

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

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

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
    background-color: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.6;
    transition: background-color 0.3s ease, color 0.3s ease;
}

h1, h2, h3, h4, .app-title {
    font-family: 'Outfit', sans-serif;
    font-weight: 700;
}

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* Language Toggle Logic */
body.lang-cz [data-en] {
    display: none !important;
}

body.lang-en [data-cz] {
    display: none !important;
}

/* Navbar */
.navbar {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 1000;
    background-color: var(--navbar-bg);
    border-bottom: 1px solid var(--border-color);
    backdrop-filter: blur(10px);
    height: 80px;
    display: flex;
    align-items: center;
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo-area {
    display: flex;
    align-items: center;
    gap: 0.75rem;
}

.logo-img {
    width: 40px;
    height: 40px;
    border-radius: 8px;
    object-fit: cover;
    border: 1px solid var(--border-color);
}

.app-title {
    font-size: 1.25rem;
    color: var(--text-primary);
    letter-spacing: -0.02em;
}

.nav-links {
    display: flex;
    gap: 2rem;
}

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.95rem;
    font-weight: 500;
    transition: color 0.2s ease;
}

.nav-links a:hover {
    color: var(--accent);
}

.controls {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.control-btn {
    background: none;
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    width: 40px;
    height: 40px;
    border-radius: 8px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all 0.2s ease;
}

.control-btn:hover {
    background-color: var(--bg-tertiary);
    border-color: var(--accent);
}

/* Dark/Light Icon Display Toggle */
html.dark .light-icon { display: none; }
html:not(.dark) .dark-icon { display: none; }

/* Lang Switcher */
.lang-switcher {
    display: flex;
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    border-radius: 8px;
    padding: 2px;
}

.lang-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    padding: 6px 12px;
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    border-radius: 6px;
    transition: all 0.2s ease;
}

.lang-btn.active {
    background-color: var(--accent);
    color: #ffffff;
}

/* Hero Section */
.hero {
    padding-top: 180px;
    padding-bottom: 80px;
}

.hero-layout {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    max-width: 1000px;
    margin: 0 auto;
}

.hero-text-center {
    max-width: 800px;
    margin-bottom: 3rem;
    display: flex;
    flex-direction: column;
    align-items: center;
}

.hero-text-center h1 {
    font-size: 3.5rem;
    line-height: 1.1;
    margin-bottom: 1.5rem;
    letter-spacing: -0.03em;
}

.hero-text-center .hero-lead {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 2rem;
    max-width: 720px;
}

.badge {
    display: inline-flex;
    align-items: center;
    gap: 0.5rem;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    padding: 6px 14px;
    border-radius: 100px;
    font-size: 0.85rem;
    color: var(--accent);
    font-weight: 600;
    margin-bottom: 1.5rem;
}

.hero-actions-row {
    display: flex;
    gap: 1.5rem;
    width: 100%;
    justify-content: center;
    margin-top: 1rem;
}

.hero-actions-row .hero-btn {
    flex: 1;
    max-width: 320px;
    white-space: nowrap;
    padding: 16px 24px;
    font-size: 1.05rem;
    border-radius: 10px;
    box-shadow: 0 4px 10px var(--shadow-color);
}

/* Button styles */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.75rem;
    padding: 14px 28px;
    border-radius: 8px;
    font-size: 1rem;
    font-weight: 600;
    text-decoration: none;
    cursor: pointer;
    transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

.btn-primary {
    background-color: var(--accent);
    color: #ffffff;
    border: 1px solid var(--accent);
}

.btn-primary:hover {
    background-color: var(--accent-hover);
    border-color: var(--accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(var(--accent-rgb), 0.2);
}

.btn-accent {
    background-color: var(--success);
    color: #ffffff;
    border: 1px solid var(--success);
}

.btn-accent:hover {
    background-color: #059669;
    border-color: #059669;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(16, 185, 129, 0.2);
}

.btn-secondary {
    background-color: var(--bg-secondary);
    color: var(--text-primary);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background-color: var(--bg-tertiary);
    border-color: var(--accent);
    transform: translateY(-2px);
}

.btn-sm {
    padding: 8px 16px;
    font-size: 0.875rem;
}

.tech-icons {
    display: flex;
    gap: 2rem;
    color: var(--text-secondary);
}

.tech-item {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-size: 0.9rem;
}

.tech-item i {
    font-size: 1.2rem;
}

.hero-image-container {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1rem;
    box-shadow: 0 20px 40px var(--shadow-color);
    overflow: hidden;
}

.hero-showcase-img {
    width: 100%;
    border-radius: 8px;
    display: block;
    object-fit: cover;
    border: 1px solid var(--border-color);
    transition: transform 0.5s ease;
}

.hero-image-container:hover .hero-showcase-img {
    transform: scale(1.02);
}

/* Sections General */
.section-padding {
    padding: 100px 0;
}

.bg-alt {
    background-color: var(--bg-secondary);
}

.section-header {
    text-align: center;
    max-width: 700px;
    margin: 0 auto 4rem auto;
}

.section-header h2 {
    font-size: 2.25rem;
    letter-spacing: -0.02em;
    margin-bottom: 1rem;
}

.section-lead {
    font-size: 1.1rem;
    color: var(--text-secondary);
}

/* Features Grid */
.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 2rem;
}

.feature-card {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 2.5rem;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 4px 6px var(--shadow-color);
}

.feature-card:hover {
    transform: translateY(-6px);
    border-color: var(--accent);
    box-shadow: 0 12px 20px var(--shadow-color);
}

.feature-icon {
    width: 48px;
    height: 48px;
    border-radius: 8px;
    background-color: var(--bg-tertiary);
    color: var(--accent);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.5rem;
    margin-bottom: 1.5rem;
    border: 1px solid var(--border-color);
}

.feature-card h3 {
    font-size: 1.25rem;
    margin-bottom: 1rem;
}

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

/* Presentation Section Content */
.presentation-content {
    display: grid;
    grid-template-columns: 1.2fr 1fr;
    gap: 4rem;
    align-items: center;
}

.video-container {
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 0.75rem;
    box-shadow: 0 20px 30px var(--shadow-color);
    overflow: hidden;
}

.video-container video {
    width: 100%;
    border-radius: 8px;
    display: block;
    background-color: #000000;
}

.presentation-info h3 {
    font-size: 1.75rem;
    margin-bottom: 1.25rem;
}

.presentation-info p {
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

.doc-card {
    display: flex;
    align-items: center;
    gap: 1.25rem;
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    padding: 1rem 1.5rem;
    border-radius: 10px;
    margin-bottom: 1rem;
    transition: border-color 0.2s ease;
}

.doc-card:hover {
    border-color: var(--accent);
}

.doc-icon {
    font-size: 2rem;
    color: var(--danger);
}

.doc-card:nth-of-type(n+2) .doc-icon {
    color: var(--accent);
}

.doc-details {
    display: flex;
    flex-direction: column;
    flex-grow: 1;
}

.doc-name {
    font-weight: 600;
    font-size: 0.95rem;
}

.doc-size {
    font-size: 0.8rem;
    color: var(--text-secondary);
    margin-top: 2px;
}

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

.download-card {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 2.5rem;
    text-align: center;
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
    box-shadow: 0 4px 6px var(--shadow-color);
    display: flex;
    flex-direction: column;
    align-items: center;
}

.download-card:hover {
    transform: translateY(-6px);
    border-color: var(--accent);
    box-shadow: 0 12px 20px var(--shadow-color);
}

.os-icon {
    width: 64px;
    height: 64px;
    border-radius: 12px;
    background-color: var(--bg-tertiary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 2.25rem;
    margin-bottom: 1.5rem;
    border: 1px solid var(--border-color);
}

.os-icon.linux { color: #f59e0b; }
.os-icon.debian { color: #d63384; }
.os-icon.flatpak { color: #2e69b5; }
.os-icon.windows { color: #3b82f6; }
.os-icon.code { color: #10b981; }

.download-card h3 {
    font-size: 1.25rem;
    margin-bottom: 0.75rem;
}

.os-desc {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    flex-grow: 1;
    min-height: 50px;
}

.file-size {
    display: inline-block;
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    padding: 4px 10px;
    border-radius: 6px;
    font-size: 0.8rem;
    font-weight: 600;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

.download-card .btn {
    width: 100%;
}

/* Open Source Section */
.open-source-grid {
    display: grid;
    grid-template-columns: 1.2fr 1fr;
    gap: 4rem;
    align-items: center;
}

.open-source-text h2 {
    font-size: 2rem;
    margin-bottom: 1.5rem;
    letter-spacing: -0.02em;
}

.open-source-text p {
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

.tech-stack-badges {
    display: flex;
    flex-wrap: wrap;
    gap: 0.75rem;
    margin-top: 2rem;
}

.tech-badge {
    background-color: var(--bg-tertiary);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    padding: 6px 14px;
    border-radius: 6px;
    font-size: 0.85rem;
    font-weight: 500;
}

.open-source-stats {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
}

.stat-card {
    background-color: var(--bg-primary);
    border: 1px solid var(--border-color);
    border-radius: 10px;
    padding: 1.5rem 2rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.stat-num {
    font-family: 'Outfit', sans-serif;
    font-size: 1.75rem;
    font-weight: 800;
    color: var(--accent);
}

.stat-label {
    font-weight: 600;
    font-size: 0.95rem;
}

/* Footer */
.footer {
    background-color: var(--bg-primary);
    border-top: 1px solid var(--border-color);
    padding: 3rem 0;
}

.footer-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1.5rem;
}

.footer-brand {
    display: flex;
    align-items: center;
    gap: 0.5rem;
    font-weight: 600;
    font-size: 1.1rem;
}

.logo-img-sm {
    width: 24px;
    height: 24px;
    border-radius: 4px;
    object-fit: cover;
}

.footer-links {
    display: flex;
    gap: 2rem;
}

.footer-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9rem;
    transition: color 0.2s ease;
}

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

.footer-copy {
    color: var(--text-secondary);
    font-size: 0.85rem;
    text-align: center;
}

/* Responsive */
@media (max-width: 968px) {
    .hero-text-center h1 {
        font-size: 2.75rem;
    }
    
    .hero-actions-row {
        gap: 1rem;
    }
    
    .hero-actions-row .hero-btn {
        padding: 12px 16px;
        font-size: 0.95rem;
    }
    
    .badge {
        justify-content: center;
    }
    
    .tech-icons {
        justify-content: center;
    }
    
    .presentation-content {
        grid-template-columns: 1fr;
        gap: 2.5rem;
    }
    
    .open-source-grid {
        grid-template-columns: 1fr;
        gap: 3rem;
    }
    
    .nav-links {
        display: none; /* simple fallback for burger navigation in raw HTML */
    }
    
    .download-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (max-width: 576px) {
    .container {
        padding: 0 1.25rem;
    }
    
    .hero {
        padding-top: 130px;
    }
    
    .hero-text-center h1 {
        font-size: 2.25rem;
    }
    
    .hero-actions-row {
        flex-direction: column;
        align-items: center;
    }
    
    .hero-actions-row .hero-btn {
        width: 100%;
        max-width: 320px;
    }
    
    .doc-card {
        flex-direction: column;
        text-align: center;
        padding: 1.5rem;
    }
    
    .doc-card .btn {
        width: 100%;
    }
    
    .download-grid {
        grid-template-columns: 1fr;
    }
}

/* Slideshow Styles */
.slideshow-container {
    position: relative;
    width: 100%;
    overflow: hidden;
    aspect-ratio: 1200 / 573;
    background-color: var(--bg-secondary);
    border-radius: 12px;
}

.slides-wrapper {
    position: relative;
    width: 100%;
    height: 100%;
}

.slide {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    opacity: 0;
    transition: opacity 0.6s ease-in-out;
    z-index: 1;
    display: flex;
    align-items: center;
    justify-content: center;
}

.slide.active {
    opacity: 1;
    z-index: 2;
}

.slide img {
    width: 100%;
    height: 100%;
    object-fit: contain; /* centering 1.png illustration correctly, others full bleed */
    border-radius: 8px;
    display: block;
}

/* Slide navigation buttons */
.slide-nav-btn {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    background-color: rgba(11, 15, 23, 0.4);
    border: 1px solid var(--border-color);
    color: var(--text-primary);
    width: 44px;
    height: 44px;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 10;
    transition: all 0.25s ease;
    backdrop-filter: blur(4px);
}

.slide-nav-btn:hover {
    background-color: var(--accent);
    color: #ffffff;
    border-color: var(--accent);
}

.prev-btn {
    left: 1rem;
}

.next-btn {
    right: 1rem;
}

/* Dots */
.slideshow-dots {
    position: absolute;
    bottom: 1rem;
    left: 50%;
    transform: translateX(-50%);
    display: flex;
    gap: 0.5rem;
    z-index: 10;
}

.dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background-color: rgba(255, 255, 255, 0.4);
    cursor: pointer;
    transition: all 0.2s ease;
}

.dot.active {
    background-color: var(--accent);
    transform: scale(1.2);
}