/* ===================================
   CSS Custom Properties
   =================================== */
:root {
    --color-primary: #2563eb;
    --color-primary-dark: #1d4ed8;
    --color-text: #1f2937;
    --color-text-muted: #6b7280;
    --color-text-light: #9ca3af;
    --color-background: #ffffff;
    --color-background-alt: #f8fafc;
    --color-background-dark: #f1f5f9;
    --color-accent: #3b82f6;
    --color-border: #e2e8f0;

    --font-primary: 'Open Sans', sans-serif;
    --font-display: 'Lobster', cursive;

    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;

    --max-width: 1200px;
    --border-radius: 8px;
    --border-radius-lg: 16px;

    --shadow-sm: 0 1px 2px 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);

    --transition: all 0.2s ease;
}

/* Dark Mode */
@media (prefers-color-scheme: dark) {
    :root {
        --color-primary: #60a5fa;
        --color-primary-dark: #3b82f6;
        --color-text: #f1f5f9;
        --color-text-muted: #94a3b8;
        --color-text-light: #64748b;
        --color-background: #0f172a;
        --color-background-alt: #1e293b;
        --color-background-dark: #334155;
        --color-accent: #38bdf8;
        --color-border: #334155;

        --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
        --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4), 0 2px 4px -1px rgba(0, 0, 0, 0.3);
        --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.4), 0 4px 6px -2px rgba(0, 0, 0, 0.3);
        --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.4), 0 10px 10px -5px rgba(0, 0, 0, 0.3);
    }
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-primary);
    color: var(--color-text);
    background: var(--color-background);
    line-height: 1.7;
    font-size: 16px;
}

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

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

a:hover {
    color: var(--color-primary-dark);
    text-decoration: underline;
}

ul {
    list-style-position: inside;
    margin-left: var(--spacing-md);
}

/* ===================================
   Typography
   =================================== */
h1 {
    font-family: var(--font-display);
    font-weight: 400;
    font-size: 2.5rem;
    background: linear-gradient(135deg, var(--color-text) 0%, var(--color-primary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

h2 {
    font-weight: 800;
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--color-primary);
    margin-bottom: var(--spacing-md);
}

h3 {
    font-weight: 600;
    font-size: 1.1rem;
    color: var(--color-text);
}

/* ===================================
   Site Header
   =================================== */
.site-header {
    background: linear-gradient(135deg, var(--color-background) 0%, var(--color-background-alt) 100%);
    border-bottom: 1px solid var(--color-border);
    padding: var(--spacing-lg) var(--spacing-xl);
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(10px);
    display: flex;
    flex-wrap: wrap;
    align-items: center;
    justify-content: center;
    gap: var(--spacing-lg);
}

.site-header .logo {
    height: 48px;
    width: auto;
    filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.1));
}

.site-header h1 {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    margin: 0;
}

.download-btn {
    display: inline-block;
    transition: var(--transition);
}

.download-btn:hover {
    transform: translateY(-2px);
    filter: brightness(1.05);
}

.download-btn img {
    height: 48px;
    width: auto;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-md);
}

.main-nav {
    margin-left: auto;
}

.main-nav ul {
    display: flex;
    gap: var(--spacing-xl);
    list-style: none;
    margin: 0;
}

.main-nav a {
    font-weight: 600;
    color: var(--color-text);
    padding: var(--spacing-sm) var(--spacing-md);
    border-radius: var(--border-radius);
    transition: var(--transition);
}

.main-nav a:hover {
    background: var(--color-background-dark);
    color: var(--color-primary);
    text-decoration: none;
}

/* ===================================
   Main Content
   =================================== */
main {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: var(--spacing-xl);
}

/* ===================================
   Content Sections
   =================================== */
.content-section {
    display: grid;
    grid-template-columns: 220px 1fr;
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-2xl);
    padding: var(--spacing-xl);
    background: var(--color-background);
    border-radius: var(--border-radius-lg);
    border: 1px solid var(--color-border);
    box-shadow: var(--shadow-sm);
    transition: var(--transition);
}

.content-section:hover {
    box-shadow: var(--shadow-md);
    border-color: var(--color-primary);
}

.section-title {
    font-weight: 800;
    position: relative;
}

.section-title::after {
    content: '';
    display: block;
    width: 40px;
    height: 3px;
    background: linear-gradient(90deg, var(--color-primary), var(--color-accent));
    margin-top: var(--spacing-sm);
    border-radius: 2px;
}

.section-body {
    color: var(--color-text-muted);
}

.section-body p {
    margin-bottom: var(--spacing-md);
    line-height: 1.8;
}


.section-body li {
    margin-bottom: var(--spacing-sm);
}

/* ===================================
   Feature Grid
   =================================== */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: var(--spacing-lg);
    margin-top: 1.5rem;
}

.feature-grid-extended {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: var(--spacing-lg);
    margin-top: 1.5rem;
    margin-bottom: 1.5rem;
}

.feature-grid-full {
    display: block;
    margin-top: 1.5rem;
}

.feature-grid-full .feature-item {
    max-width: 100%;
    text-align: center;
}

.feature-grid-full .feature-item img {
    width: 100%;
    height: auto;
    max-width: 100%;
}

.feature-item {
    text-align: center;
    font-size: 0.85rem;
    padding: var(--spacing-md);
    background: var(--color-background-alt);
    border-radius: var(--border-radius);
    border: 1px solid transparent;
    transition: var(--transition);
}

.feature-item:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--color-primary);
    background: var(--color-background);
}

.feature-item img {
    margin: 0 auto var(--spacing-md);
    max-width: 100%;
    border-radius: var(--border-radius);
    box-shadow: var(--shadow-sm);
}

.feature-item figcaption {
    color: var(--color-text-muted);
    line-height: 1.5;
}

.feature-item-wide {
    grid-column: span 2;
}

.feature-item-wide img {
    max-width: 100%;
}

/* ===================================
   Slideshow
   =================================== */
.slideshow-section {
    margin-bottom: var(--spacing-2xl);
    padding: var(--spacing-xl);
    background: linear-gradient(135deg, var(--color-background-alt) 0%, var(--color-background-dark) 100%);
    border-radius: var(--border-radius-lg);
    border: 1px solid var(--color-border);
}

.slideshow-wrapper {
    display: grid;
    grid-template-columns: 1fr 320px;
    gap: var(--spacing-xl);
    align-items: start;
}

#slideshow {
    position: relative;
}

.slideshow-slides {
    position: relative;
    background: var(--color-background);
    border-radius: var(--border-radius-lg);
    overflow: hidden;
    box-shadow: var(--shadow-xl);
}

.slide {
    width: 100%;
}

.slide img {
    width: 100%;
    height: auto;
}

.slide-caption {
    padding: var(--spacing-lg);
    font-size: 0.95rem;
    text-align: center;
    background: linear-gradient(180deg, var(--color-background) 0%, var(--color-background-alt) 100%);
    color: var(--color-text-muted);
    border-top: 1px solid var(--color-border);
}

/* Slideshow Thumbnails */
.slideshow-nav {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: var(--spacing-sm);
    max-height: 520px;
    overflow-y: auto;
    padding-right: var(--spacing-sm);
}

.slideshow-nav::-webkit-scrollbar {
    width: 6px;
}

.slideshow-nav::-webkit-scrollbar-track {
    background: var(--color-background-dark);
    border-radius: 3px;
}

.slideshow-nav::-webkit-scrollbar-thumb {
    background: var(--color-border);
    border-radius: 3px;
}

.slideshow-nav::-webkit-scrollbar-thumb:hover {
    background: var(--color-text-light);
}

.slideshow-thumb {
    display: block;
    padding: 0;
    background: var(--color-background);
    border: 2px solid var(--color-border);
    border-radius: var(--border-radius);
    cursor: pointer;
    text-align: center;
    font-size: 0.7rem;
    font-family: var(--font-primary);
    overflow: hidden;
    transition: var(--transition);
    box-shadow: var(--shadow-sm);
}

.slideshow-thumb:hover {
    border-color: var(--color-primary);
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.slideshow-thumb.active {
    border-color: var(--color-primary);
    background: var(--color-primary);
    box-shadow: var(--shadow-lg);
}

.slideshow-thumb.active span {
    color: white;
}

.slideshow-thumb img {
    width: 100%;
    height: auto;
    display: block;
}

.slideshow-thumb span {
    display: block;
    padding: var(--spacing-xs) var(--spacing-sm);
    color: var(--color-text-muted);
    font-weight: 500;
    transition: var(--transition);
}

/* ===================================
   Footer
   =================================== */
.site-footer {
    text-align: center;
    padding: var(--spacing-md) var(--spacing-lg);
    margin-top: var(--spacing-xl);
    background: var(--color-background-alt);
    border-top: 1px solid var(--color-border);
    color: var(--color-text-light);
    font-size: 0.75rem;
}

.site-footer p {
    margin-bottom: var(--spacing-xs);
}

.site-footer p:last-child {
    margin-bottom: 0;
}

/* ===================================
   Release List
   =================================== */
.release-list {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column;
    gap: var(--spacing-xs);
}

.release-item {
    display: grid;
    grid-template-columns: 48px 90px 1fr;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-md);
    background: var(--color-background-alt);
    border-radius: var(--border-radius);
    border-left: 3px solid var(--color-primary);
    transition: var(--transition);
}

.release-item:hover {
    background: var(--color-background-dark);
    border-left-color: var(--color-accent);
}

.release-version {
    font-weight: 700;
    font-size: 0.75rem;
    color: var(--color-background);
    background: linear-gradient(135deg, var(--color-primary), var(--color-accent));
    padding: 2px var(--spacing-xs);
    border-radius: 4px;
    text-align: center;
}

.release-date {
    font-size: 0.75rem;
    color: var(--color-text-muted);
}

.release-desc {
    margin: 0;
    font-size: 0.8rem;
    line-height: 1.4;
    color: var(--color-text);
}

@media (max-width: 600px) {
    .release-item {
        grid-template-columns: 48px 1fr;
        grid-template-rows: auto auto;
    }

    .release-date {
        grid-column: 2;
    }

    .release-desc {
        grid-column: 1 / -1;
    }
}

/* ===================================
   Footer
   =================================== */
.site-footer {
    text-align: center;
    padding: var(--spacing-md) var(--spacing-lg);
    margin-top: var(--spacing-xl);
    background: var(--color-background-alt);
    border-top: 1px solid var(--color-border);
    color: var(--color-text-light);
    font-size: 0.75rem;
}

.site-footer p {
    margin-bottom: var(--spacing-xs);
}

.site-footer p:last-child {
    margin-bottom: 0;
}

/* ===================================
   Responsive Design
   =================================== */
@media (max-width: 1024px) {
    .slideshow-wrapper {
        grid-template-columns: 1fr 280px;
    }
}

@media (max-width: 900px) {
    .slideshow-wrapper {
        grid-template-columns: 1fr;
    }

    .slideshow-nav {
        grid-template-columns: repeat(4, 1fr);
        max-height: none;
    }
}

@media (max-width: 768px) {
    .content-section {
        grid-template-columns: 1fr;
        padding: var(--spacing-lg);
    }

    .section-title {
        margin-bottom: var(--spacing-md);
    }

    .site-header {
        padding: var(--spacing-md);
    }

    .main-nav {
        width: 100%;
        margin-left: 0;
        margin-top: var(--spacing-sm);
    }

    .main-nav ul {
        justify-content: center;
    }

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

    .feature-item-wide {
        grid-column: span 1;
    }

    .feature-grid {
        grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    }

    h1 {
        font-size: 2rem;
    }
}

@media (max-width: 480px) {
    h1 {
        font-size: 1.5rem;
    }

    .site-header .logo,
    .download-btn img {
        height: 40px;
    }

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

    main {
        padding: var(--spacing-md);
    }

    .content-section {
        padding: var(--spacing-md);
        margin-bottom: var(--spacing-lg);
    }

    .slideshow-section {
        padding: var(--spacing-md);
        margin-bottom: var(--spacing-lg);
    }

    .feature-grid {
        gap: var(--spacing-md);
    }

    .feature-item {
        padding: var(--spacing-sm);
    }
}