:root {
    --primary: #007AFF;
    --primary-dark: #0051a8;
    --bg: #ffffff;
    --text: #1d1d1f;
    --text-muted: #86868b;
    --surface: #f5f5f7;
    --glass: rgba(255, 255, 255, 0.8);
    --border: rgba(0, 0, 0, 0.1);
    --transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg: #000000;
        --text: #f5f5f7;
        --text-muted: #86868b;
        --surface: #1c1c1e;
        --glass: rgba(0, 0, 0, 0.7);
        --border: rgba(255, 255, 255, 0.1);
    }
}

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

body {
    font-family: 'Inter', 'Noto Sans JP', -apple-system, BlinkMacSystemFont, sans-serif;
    background-color: var(--bg);
    color: var(--text);
    line-height: 1.5;
    -webkit-font-smoothing: antialiased;
    overflow-x: hidden;
}

.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 2rem;
}

/* Header */
header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    height: 64px;
    background: var(--glass);
    backdrop-filter: blur(20px);
    -webkit-backdrop-filter: blur(20px);
    border-bottom: 1px solid var(--border);
    z-index: 1000;
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 100%;
}

.logo {
    display: flex;
    align-items: center;
    gap: 0.75rem;
    font-weight: 800;
    font-size: 1.25rem;
}

.logo img {
    height: 32px;
    width: 32px;
}

nav ul {
    display: flex;
    list-style: none;
    gap: 2rem;
}

nav a {
    text-decoration: none;
    color: var(--text);
    font-size: 0.9rem;
    font-weight: 500;
    transition: var(--transition);
}

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

/* Hero */
.hero {
    padding-top: 160px;
    padding-bottom: 100px;
    background: radial-gradient(circle at top right, rgba(0, 122, 255, 0.05), transparent 40%),
                radial-gradient(circle at bottom left, rgba(0, 122, 255, 0.05), transparent 40%);
}

.hero-content {
    display: grid;
    grid-template-columns: 1fr 1fr;
    align-items: center;
    gap: 4rem;
}

.hero-text h1 {
    font-size: 4rem;
    font-weight: 800;
    line-height: 1.1;
    margin-bottom: 1.5rem;
    letter-spacing: -0.02em;
}

.highlight {
    color: var(--primary);
}

.hero-text p {
    font-size: 1.25rem;
    color: var(--text-muted);
    margin-bottom: 2.5rem;
    max-width: 500px;
}

.btn {
    display: inline-block;
    padding: 0.75rem 2rem;
    border-radius: 99px;
    font-weight: 600;
    text-decoration: none;
    transition: var(--transition);
}

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

.cta-buttons {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
}

.btn-store {
    padding: 0;
    transition: var(--transition);
}

.btn-store img {
    height: 44px;
    width: auto;
}

.btn-store:hover {
    transform: translateY(-2px);
    opacity: 0.9;
}

.hero-image {
    position: relative;
    display: flex;
    justify-content: center;
}

.hero-image img {
    width: 100%;
    max-width: 380px;
    border-radius: 40px;
    box-shadow: 0 30px 60px rgba(0, 0, 0, 0.15);
}

.floating {
    animation: float 6s ease-in-out infinite;
}

@keyframes float {
    0%, 100% { transform: translateY(0); }
    50% { transform: translateY(-20px); }
}

/* Features */
.features {
    padding: 100px 0;
    background: var(--surface);
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    font-weight: 800;
    margin-bottom: 4rem;
}

.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 2rem;
}

.feature-card {
    background: var(--bg);
    padding: 2.5rem;
    border-radius: 24px;
    border: 1px solid var(--border);
    transition: var(--transition);
}

.feature-card:hover {
    transform: translateY(-10px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.05);
}

.feature-card .icon {
    font-size: 2.5rem;
    margin-bottom: 1.5rem;
}

.feature-card h3 {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: 1rem;
}

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

/* Gallery */
.gallery {
    padding: 100px 0;
}

.gallery-scroll {
    display: flex;
    overflow-x: auto;
    gap: 1.5rem;
    padding: 2rem 0;
    scrollbar-width: none; /* Firefox */
}

.gallery-scroll::-webkit-scrollbar {
    display: none; /* Chrome/Safari */
}

.gallery-scroll img {
    height: 500px;
    border-radius: 24px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    transition: var(--transition);
}

.gallery-scroll img:hover {
    transform: scale(1.02);
}

/* About */
.about {
    padding: 100px 0;
    text-align: center;
    background: radial-gradient(circle at center, rgba(0, 122, 255, 0.1), transparent 70%);
}

.about-content h2 {
    font-size: 3rem;
    font-weight: 800;
    margin-bottom: 1.5rem;
}

.about-content p {
    font-size: 1.25rem;
    color: var(--text-muted);
    max-width: 700px;
    margin: 0 auto;
}

/* Footer */
footer {
    padding: 60px 0;
    border-top: 1px solid var(--border);
    text-align: center;
}

footer p {
    color: var(--text-muted);
    font-size: 0.9rem;
    margin-bottom: 1rem;
}

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

.footer-links a {
    text-decoration: none;
    color: var(--text-muted);
    font-size: 0.85rem;
    transition: var(--transition);
}

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

/* Header Scrolled State */
header.scrolled {
    height: 56px;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.05);
}

/* Scroll Reveal */
.feature-card, .section-title, .hero-text, .hero-image {
    opacity: 0;
    transform: translateY(30px);
    transition: opacity 0.8s ease-out, transform 0.8s ease-out;
}

.feature-card.revealed, .section-title.revealed, .hero-text.revealed, .hero-image.revealed {
    opacity: 1;
    transform: translateY(0);
}

.feature-card:nth-child(2) { transition-delay: 0.1s; }
.feature-card:nth-child(3) { transition-delay: 0.2s; }
.feature-card:nth-child(4) { transition-delay: 0.3s; }

/* Responsive */
@media (max-width: 900px) {
    .hero-content {
        grid-template-columns: 1fr;
        text-align: center;
    }
    
    .hero-text h1 {
        font-size: 3rem;
    }
    
    .hero-text p {
        margin-left: auto;
        margin-right: auto;
    }
    
    .hero-image {
        order: -1;
    }
    
    .hero-image img {
        max-width: 300px;
    }
}

@media (max-width: 600px) {
    .hero-text h1 {
        font-size: 2.5rem;
    }
    
    nav ul {
        display: none;
    }
}

/* Language Switcher */
.lang-switch {
    display: flex;
    align-items: center;
    gap: 0.3rem;
    font-size: 0.75rem;
    font-weight: 700;
    color: var(--text-muted);
    margin-left: 0.5rem;
    padding: 0.2rem 0.6rem;
    background: var(--surface);
    border-radius: 20px;
    border: 1px solid var(--border);
}

.lang-switch button {
    background: none;
    border: none;
    color: inherit;
    font-family: inherit;
    font-weight: inherit;
    font-size: inherit;
    cursor: pointer;
    padding: 0;
    transition: var(--transition);
}

.lang-switch button:hover {
    color: var(--primary);
}

.lang-switch button.active {
    color: var(--primary);
}

/* Language Visibility */
body.lang-en .lang-ja { display: none !important; }
body.lang-ja .lang-en { display: none !important; }