/* ===== CSS Variables & Reset ===== */
:root {
    --bg-dark: #0a0a0f;
    --bg-card: #12121a;
    --bg-card-hover: #1a1a25;
    --accent-primary: #ff6b9d;
    --accent-secondary: #c084fc;
    --accent-tertiary: #60a5fa;
    --text-primary: #f0f0f5;
    --text-secondary: #9090a0;
    --text-muted: #606070;
    --border-subtle: rgba(255, 255, 255, 0.08);
    --gradient-hero: linear-gradient(135deg, #ff6b9d 0%, #c084fc 50%, #60a5fa 100%);
    --gradient-card: linear-gradient(180deg, rgba(255,107,157,0.05) 0%, transparent 100%);
    --shadow-glow: 0 0 60px rgba(255, 107, 157, 0.15);
    --radius-sm: 8px;
    --radius-md: 12px;
    --radius-lg: 20px;
    --transition: 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

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

html {
    scroll-behavior: smooth;
}

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

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

/* ===== Navigation ===== */
.nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 40px;
    position: relative;
    z-index: 100;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 12px;
}

.logo {
    font-family: 'Noto Sans JP', sans-serif;
    font-size: 1.5rem;
    font-weight: 700;
    background: var(--gradient-hero);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.logo-english {
    font-weight: 600;
    font-size: 1.1rem;
    color: var(--text-primary);
}

.nav-links {
    display: flex;
    gap: 32px;
}

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: color var(--transition);
}

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

/* ===== Hero Section ===== */
.hero {
    position: relative;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    overflow: hidden;
}

.hero-bg {
    position: absolute;
    inset: 0;
    background: 
        radial-gradient(ellipse 80% 50% at 50% -20%, rgba(255, 107, 157, 0.15) 0%, transparent 50%),
        radial-gradient(ellipse 60% 40% at 80% 60%, rgba(96, 165, 250, 0.1) 0%, transparent 50%);
    pointer-events: none;
}

.hero-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    text-align: center;
    padding: 60px 40px 40px;
    position: relative;
    z-index: 10;
}

.hero-title {
    font-size: clamp(2.5rem, 6vw, 4.5rem);
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: 24px;
}

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

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin-bottom: 40px;
}

.hero-buttons {
    display: flex;
    gap: 16px;
    flex-wrap: wrap;
    justify-content: center;
}

.btn {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    padding: 14px 28px;
    border-radius: var(--radius-md);
    font-weight: 600;
    font-size: 1rem;
    text-decoration: none;
    transition: all var(--transition);
    cursor: pointer;
    border: none;
}

.btn-primary {
    background: var(--gradient-hero);
    color: white;
    box-shadow: 0 4px 20px rgba(255, 107, 157, 0.3);
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 30px rgba(255, 107, 157, 0.4);
}

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

.btn-secondary:hover {
    background: rgba(255, 255, 255, 0.05);
    border-color: rgba(255, 255, 255, 0.15);
}

/* ===== Hero Preview (Mock Window) ===== */
.hero-preview {
    padding: 0 40px 60px;
    display: flex;
    justify-content: center;
    position: relative;
    z-index: 10;
}

.preview-window {
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    overflow: hidden;
    max-width: 700px;
    width: 100%;
    box-shadow: var(--shadow-glow);
}

.preview-header {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 16px;
    background: rgba(0, 0, 0, 0.3);
    border-bottom: 1px solid var(--border-subtle);
}

.preview-title {
    font-size: 0.85rem;
    color: var(--text-muted);
}

.preview-content {
    padding: 0;
    position: relative;
}

/* ===== Hero Slideshow ===== */
.slideshow-content {
    display: flex;
    flex-direction: column;
}

.slideshow-slides {
    position: relative;
    aspect-ratio: 16 / 9;
    background: #0a0a0f;
    overflow: hidden;
}

img.slideshow-slide,
video.slideshow-slide {
    position: absolute;
    inset: 0;
    width: 100%;
    height: 100%;
    object-fit: contain;
    opacity: 0;
    transition: opacity 0.5s ease;
    pointer-events: none;
}

img.slideshow-slide.active,
video.slideshow-slide.active {
    opacity: 1;
    pointer-events: auto;
}

.slideshow-dots {
    display: flex;
    justify-content: center;
    gap: 10px;
    padding: 14px 16px;
    background: rgba(0, 0, 0, 0.2);
}

.slideshow-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
    border: none;
    background: var(--text-muted);
    cursor: pointer;
    transition: all var(--transition);
    padding: 0;
}

.slideshow-dot:hover {
    background: var(--text-secondary);
    transform: scale(1.2);
}

.slideshow-dot.active {
    background: var(--accent-primary);
    box-shadow: 0 0 8px rgba(255, 107, 157, 0.5);
}

/* ===== Features Section ===== */
.features {
    padding: 100px 0;
    background: linear-gradient(180deg, transparent 0%, rgba(18, 18, 26, 0.5) 100%);
}

.section-title {
    font-size: 2.5rem;
    font-weight: 700;
    text-align: center;
    margin-bottom: 12px;
}

.section-subtitle {
    text-align: center;
    color: var(--text-secondary);
    font-size: 1.1rem;
    margin-bottom: 60px;
}

.features-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(320px, 1fr));
    gap: 24px;
}

.feature-card {
    background: var(--bg-card);
    border: 1px solid var(--border-subtle);
    border-radius: var(--radius-lg);
    padding: 32px;
    transition: all var(--transition);
}

.feature-card:hover {
    background: var(--bg-card-hover);
    border-color: rgba(255, 255, 255, 0.12);
    transform: translateY(-4px);
}

.feature-gif {
    margin-bottom: 16px;
    border-radius: var(--radius-md);
    overflow: hidden;
    border: 1px solid var(--border-subtle);
    aspect-ratio: 16 / 9;
    background: #0a0a0f;
}

.feature-gif img,
.feature-gif video {
    width: 100%;
    height: 100%;
    display: block;
    cursor: pointer;
    object-fit: contain;
}

/* ===== Lightbox ===== */
.lightbox {
    display: none;
    position: fixed;
    inset: 0;
    z-index: 2000;
    background: rgba(0, 0, 0, 0.9);
    justify-content: center;
    align-items: center;
    cursor: pointer;
}

.lightbox.active {
    display: flex;
}

.lightbox img,
.lightbox video {
    max-width: 85vw;
    max-height: 90vh;
    border-radius: var(--radius-md);
    box-shadow: 0 0 60px rgba(0, 0, 0, 0.5);
    cursor: default;
}

#lightbox-video {
    display: none;
}

.lightbox-arrow {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.15);
    color: var(--text-primary);
    font-size: 2.5rem;
    width: 50px;
    height: 50px;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: all var(--transition);
    z-index: 2001;
    line-height: 1;
    padding: 0 0 3px 0;
}

.lightbox-arrow:hover {
    background: rgba(255, 255, 255, 0.2);
    border-color: rgba(255, 255, 255, 0.3);
}

.lightbox-prev {
    left: 20px;
}

.lightbox-next {
    right: 20px;
}

.feature-card h3 {
    font-size: 1.25rem;
    font-weight: 600;
    margin-bottom: 12px;
}

.feature-card p {
    color: var(--text-secondary);
    font-size: 0.95rem;
    line-height: 1.7;
}

/* ===== Download Section ===== */
.download {
    padding: 100px 0;
    background: linear-gradient(180deg, transparent 0%, rgba(255, 107, 157, 0.03) 100%);
}

.download-hero {
    display: flex;
    justify-content: center;
}

.download-info {
    text-align: center;
    max-width: 500px;
}

.btn-download-main {
    padding: 18px 40px;
    font-size: 1.1rem;
    box-shadow: 0 4px 25px rgba(255, 107, 157, 0.3);
}

.btn-download-main:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 35px rgba(255, 107, 157, 0.4);
}

/* ===== Footer ===== */
.footer {
    padding: 60px 0 40px;
    border-top: 1px solid var(--border-subtle);
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    flex-wrap: wrap;
    gap: 40px;
    margin-bottom: 40px;
}

.footer-brand .logo {
    font-size: 2rem;
    margin-bottom: 12px;
    display: block;
}

.footer-brand p {
    color: var(--text-muted);
    max-width: 300px;
}

.footer-links {
    display: flex;
    gap: 32px;
}

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

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

.footer-credits {
    text-align: center;
    color: var(--text-muted);
    font-size: 0.9rem;
    padding-top: 20px;
    border-top: 1px solid var(--border-subtle);
}

.footer-credits a {
    color: var(--accent-primary);
    text-decoration: none;
}

/* ===== Responsive ===== */
@media (max-width: 768px) {
    .nav {
        flex-direction: column;
        gap: 16px;
        padding: 16px 20px;
    }
    
    .nav-links {
        gap: 20px;
    }
    
    .hero-content {
        padding: 40px 20px;
    }
    
    .hero-title {
        font-size: 2rem;
    }
    
    .hero-subtitle {
        font-size: 1rem;
    }
    
    .hero-preview {
        padding: 0 20px 40px;
    }
    
    .section-title {
        font-size: 1.75rem;
    }

    .footer-content {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }
    
    .footer-brand p {
        max-width: none;
    }
}