/* CSS Custom Properties for Theming */
:root {
    --bg-color: #ffffff;
    --text-primary: #1a1a1a;
    --text-secondary: #666666;
    --border-color: #eaeaea;
    --accent-color: #000000;

    --font-heading: 'Shippori Mincho', serif;
    --font-body: 'Noto Sans JP', sans-serif;

    --transition-smooth: 0.6s cubic-bezier(0.22, 1, 0.36, 1);
    --transition-fast: 0.3s ease;
}

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

html {
    scroll-behavior: smooth;
}

body {
    background-color: var(--bg-color);
    color: var(--text-primary);
    font-family: var(--font-body);
    line-height: 1.6;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

/* Typography */
h1,
h2,
h3,
.logo {
    font-family: var(--font-heading);
    font-weight: 500;
}

/* Layout Utilities */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 5%;
}

/* Header */
.header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    z-index: 100;
    background: rgba(255, 255, 255, 0.9);
    backdrop-filter: blur(8px);
    border-bottom: 1px solid transparent;
    transition: border-color var(--transition-fast);
}

.header:hover {
    border-bottom: 1px solid var(--border-color);
}

.header-container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    height: 80px;
}

.logo {
    font-size: 1.25rem;
    letter-spacing: 0.05em;
    text-decoration: none;
    color: var(--text-primary);
}

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

.nav-link {
    text-decoration: none;
    color: var(--text-primary);
    font-size: 0.9rem;
    letter-spacing: 0.05em;
    position: relative;
    padding-bottom: 4px;
}

.nav-link::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 1px;
    background-color: var(--accent-color);
    transition: width var(--transition-fast);
}

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

/* Hero Section */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    padding-top: 80px;
    gap: 4rem;
}

.hero-content {
    flex: 1;
    max-width: 500px;
}

.hero-title {
    font-size: clamp(2.5rem, 5vw, 4rem);
    line-height: 1.2;
    margin-bottom: 1.5rem;
    letter-spacing: 0.02em;
}

.hero-subtitle {
    font-size: 1.1rem;
    color: var(--text-secondary);
    margin-bottom: 3rem;
    line-height: 1.8;
}

.hero-actions {
    display: flex;
    gap: 1rem;
}

.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 1rem 2rem;
    font-size: 0.95rem;
    text-decoration: none;
    transition: all var(--transition-fast);
    letter-spacing: 0.05em;
    border-radius: 2px;
}

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

.btn-primary:hover {
    background-color: transparent;
    color: var(--accent-color);
}

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

.btn-secondary:hover {
    border-color: var(--accent-color);
}

.hero-image-wrapper {
    flex: 1;
    position: relative;
}

.hero-image {
    width: 100%;
    height: auto;
    object-fit: cover;
    aspect-ratio: 4/5;
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.06);
    transition: transform var(--transition-smooth);
}

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

.image-accent {
    position: absolute;
    top: -20px;
    right: -20px;
    width: 100%;
    height: 100%;
    border: 1px solid var(--border-color);
    z-index: -1;
}

/* Concept Section */
.concept {
    padding: 120px 5%;
    text-align: center;
}

.concept-inner {
    max-width: 600px;
    margin: 0 auto;
}

.section-title {
    font-size: 1rem;
    letter-spacing: 0.2em;
    text-transform: uppercase;
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

.section-text {
    font-size: 1.5rem;
    font-family: var(--font-heading);
    line-height: 2;
    color: var(--text-primary);
}

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

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

.footer-logo {
    font-family: var(--font-heading);
    font-weight: 500;
}

.copyright {
    font-size: 0.8rem;
    color: var(--text-secondary);
}

/* Animations */
.animate-fade-in {
    animation: fadeIn 1s ease forwards;
}

.animate-slide-up {
    animation: slideUp 1.2s cubic-bezier(0.22, 1, 0.36, 1) forwards;
}

.animate-fade-in-delayed {
    opacity: 0;
    animation: fadeIn 1.5s ease forwards 0.3s;
}

@keyframes fadeIn {
    from {
        opacity: 0;
    }

    to {
        opacity: 1;
    }
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(40px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Responsive */
@media (max-width: 768px) {
    .hero {
        flex-direction: column-reverse;
        padding-top: 120px;
        padding-bottom: 60px;
        text-align: center;
    }

    .hero-actions {
        justify-content: center;
    }

    .hero-image-wrapper {
        width: 100%;
        max-width: 400px;
        margin: 0 auto;
    }

    .section-text {
        font-size: 1.2rem;
    }

    .nav {
        display: none;
        /* simple mobile nav approach for sample */
    }
}