/* Color Palette & Custom Properties */
:root {
    --color-bg: #f5f5f7;
    --color-surface: #ffffff;
    --color-text-primary: #1d1d1f;
    --color-text-secondary: #86868b;
    --color-accent: #2d5a3e; /* Deep Green / Plants vibe */
    --color-accent-hover: #22432e;
    --color-border: #e8e8ed;
    --font-sans: 'Inter', 'Noto Sans JP', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    
    --shadow-sm: 0 4px 6px rgba(0, 0, 0, 0.04);
    --shadow-md: 0 10px 15px rgba(0, 0, 0, 0.08);
    --shadow-lg: 0 20px 25px rgba(0, 0, 0, 0.1);
    
    --transition-fast: 0.2s ease;
    --transition-normal: 0.3s cubic-bezier(0.25, 1, 0.5, 1);
}

/* Reset & Base Styles */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

body {
    font-family: var(--font-sans);
    background-color: var(--color-bg);
    color: var(--color-text-primary);
    line-height: 1.6;
    display: flex;
    flex-direction: column;
    min-height: 100vh;
}

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

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

/* Typography */
h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.2;
    letter-spacing: -0.02em;
}

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

.container-narrow {
    max-width: 800px;
}

main {
    flex-grow: 1;
}

/* Navigation */
.navbar {
    background-color: rgba(255, 255, 255, 0.8);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    position: sticky;
    top: 0;
    z-index: 100;
    border-bottom: 1px solid var(--color-border);
}

.nav-content {
    max-width: 1200px;
    margin: 0 auto;
    padding: 16px 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.25rem;
    font-weight: 600;
    color: var(--color-text-primary);
    letter-spacing: -0.02em;
}

.logo:hover {
    color: var(--color-text-primary);
}

.nav-links {
    display: flex;
    gap: 24px;
}

.nav-links a {
    color: var(--color-text-secondary);
    font-size: 0.9rem;
    font-weight: 400;
}

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

/* Button */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 12px 24px;
    border-radius: 30px;
    font-size: 1rem;
    font-weight: 600;
    text-align: center;
    cursor: pointer;
    transition: all var(--transition-normal);
}

.btn-primary {
    background-color: var(--color-accent);
    color: white;
    border: none;
}

.btn-primary:hover {
    background-color: var(--color-accent-hover);
    color: white;
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

/* Hero Section */
.hero {
    text-align: center;
    padding: 100px 24px 80px;
}

.hero-title {
    font-size: clamp(3rem, 8vw, 5rem);
    margin-bottom: 16px;
    background: linear-gradient(135deg, #1d1d1f 0%, #434346 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-subtitle {
    font-size: clamp(1.1rem, 3vw, 1.5rem);
    color: var(--color-text-secondary);
    max-width: 600px;
    margin: 0 auto 40px;
    font-weight: 300;
}

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

/* Apps Section */
.apps-section {
    padding: 60px 0 100px;
}

.section-title {
    text-align: center;
    font-size: 2rem;
    margin-bottom: 48px;
}

.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 32px;
}

/* App Card */
.app-card {
    background-color: var(--color-surface);
    border-radius: 20px;
    padding: 32px;
    display: flex;
    flex-direction: column;
    box-shadow: var(--shadow-sm);
    transition: transform var(--transition-normal), box-shadow var(--transition-normal);
    border: 1px solid var(--color-border);
    color: inherit;
    text-decoration: none;
}

.app-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
    color: inherit;
}

.card-icon {
    width: 56px;
    height: 56px;
    border-radius: 16px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 24px;
}

.card-title {
    font-size: 1.25rem;
    margin-bottom: 12px;
}

.card-desc {
    color: var(--color-text-secondary);
    font-size: 0.95rem;
    flex-grow: 1;
}

/* Basic Page Content (Privacy Policy etc) */
.page-content {
    padding: 80px 24px;
}

.page-title {
    font-size: 2.5rem;
    margin-bottom: 48px;
    padding-bottom: 24px;
    border-bottom: 1px solid var(--color-border);
}

.policy-section {
    margin-bottom: 40px;
}

.policy-section h2 {
    font-size: 1.5rem;
    margin-bottom: 16px;
    color: var(--color-text-primary);
}

.policy-section p {
    color: var(--color-text-secondary);
    margin-bottom: 16px;
}

.back-link {
    margin-top: 60px;
}

/* Footer */
.footer {
    background-color: var(--color-surface);
    border-top: 1px solid var(--color-border);
    padding: 40px 24px;
    margin-top: auto;
}

.footer-content {
    max-width: 1200px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 16px;
    color: var(--color-text-secondary);
    font-size: 0.85rem;
}

.footer-links {
    display: flex;
    gap: 24px;
    flex-wrap: wrap;
    justify-content: center;
}

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

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

@media (min-width: 768px) {
    .footer-content {
        flex-direction: row;
        justify-content: space-between;
    }
}