/* CSS Variables */
:root {
    --primary-color: #0066cc;
    --primary-color-dark: #0052a3;
    --text-primary: #333;
    --text-secondary: #666;
    --bg-primary: #fff;
    --bg-secondary: #f5f5f5;
    --border-color: #ddd;
    --border-color-dark: #ccc;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans JP", sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f8f9fa;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
}

/* Header Styles */
.header {
    background: white;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    position: sticky;
    top: 0;
    z-index: 100;
}

.header-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Navigation */
.nav {
    display: flex;
    align-items: center;
    padding: 1rem 0;
}

.nav-brand {
    font-size: 1.5rem;
    font-weight: bold;
    color: #333;
    text-decoration: none;
    margin-right: auto;
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 1rem;
}

.nav-item {
    position: relative;
}

.nav-link {
    display: block;
    padding: 0.5rem 1rem;
    color: #333;
    text-decoration: none;
    border-radius: 4px;
    transition: background-color 0.3s;
}

.nav-link:hover {
    background-color: #f0f0f0;
}

.nav-link.active {
    background-color: #007bff;
    color: white;
}

/* Mobile Menu */
.mobile-menu-toggle {
    display: none;
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    padding: 0.5rem;
}

/* Main Content */
.main {
    flex: 1;
    max-width: 1200px;
    width: 100%;
    margin: 0 auto;
    padding: 2rem 20px;
}

/* Footer */
.footer {
    background: #333;
    color: white;
    padding: 2rem 0;
    margin-top: auto;
}

.footer-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 2rem;
    margin-bottom: 2rem;
}

.footer-section h3 {
    margin-bottom: 1rem;
}

.footer-links {
    list-style: none;
}

.footer-link {
    color: #ccc;
    text-decoration: none;
    padding: 0.25rem 0;
    display: block;
    transition: color 0.3s;
}

.footer-link:hover {
    color: white;
}

.footer-bottom {
    text-align: center;
    padding-top: 2rem;
    border-top: 1px solid #555;
    color: #999;
}

/* Language Selector */
.language-selector {
    display: flex;
    gap: 0.5rem;
    margin-left: 1rem;
}

.language-link {
    padding: 0.25rem 0.5rem;
    color: #666;
    text-decoration: none;
    border-radius: 4px;
    font-size: 0.9rem;
}

.language-link:hover {
    background-color: #f0f0f0;
}

.language-link.active {
    background-color: #007bff;
    color: white;
}

/* Page Content */
.page-content {
    max-width: 800px;
    margin: 0 auto;
}

.page-title {
    font-size: 2.5rem;
    margin-bottom: 2rem;
    color: #333;
}

.page-body {
    font-size: 1.1rem;
    line-height: 1.8;
}

.page-body h2 {
    font-size: 2rem;
    margin-top: 2rem;
    margin-bottom: 1rem;
    color: #333;
}

.page-body h3 {
    font-size: 1.5rem;
    margin-top: 1.5rem;
    margin-bottom: 0.75rem;
    color: #555;
}

.page-body p {
    margin-bottom: 1rem;
}

.page-body ul {
    margin-bottom: 1rem;
    padding-left: 2rem;
}

.page-body li {
    margin-bottom: 0.5rem;
}

/* Container */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Cards */
.card {
    background: white;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    padding: 1.5rem;
    margin-bottom: 1.5rem;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.5rem 1rem;
    border-radius: 4px;
    text-decoration: none;
    transition: background-color 0.3s, color 0.3s;
    cursor: pointer;
    border: none;
    font-size: 1rem;
}

.btn-primary {
    background-color: #007bff;
    color: white;
}

.btn-primary:hover {
    background-color: #0056b3;
}

.btn-secondary {
    background-color: #6c757d;
    color: white;
}

.btn-secondary:hover {
    background-color: #545b62;
}

/* Utilities */
.text-center {
    text-align: center;
}

.text-left {
    text-align: left;
}

.text-right {
    text-align: right;
}

.mb-1 { margin-bottom: 0.5rem; }
.mb-2 { margin-bottom: 1rem; }
.mb-3 { margin-bottom: 1.5rem; }
.mb-4 { margin-bottom: 2rem; }

.mt-1 { margin-top: 0.5rem; }
.mt-2 { margin-top: 1rem; }
.mt-3 { margin-top: 1.5rem; }
.mt-4 { margin-top: 2rem; }

.p-1 { padding: 0.5rem; }
.p-2 { padding: 1rem; }
.p-3 { padding: 1.5rem; }
.p-4 { padding: 2rem; }

/* Responsive Design */
@media (max-width: 768px) {
    .mobile-menu-toggle {
        display: block;
    }
    
    .nav-menu {
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: white;
        flex-direction: column;
        padding: 1rem 0;
        box-shadow: 0 2px 4px rgba(0,0,0,0.1);
        display: none;
    }
    
    .nav-menu.active {
        display: flex;
    }
    
    .footer-content {
        grid-template-columns: 1fr;
    }

    .page-title {
        font-size: 2rem;
    }
    
    .page-body {
        font-size: 1rem;
    }
    
    .page-body h2 {
        font-size: 1.5rem;
    }
    
    .page-body h3 {
        font-size: 1.25rem;
    }
}

@media (max-width: 480px) {
    .header-container,
    .footer-container,
    .container {
        padding: 0 15px;
    }
    
    .nav {
        padding: 0.75rem 0;
    }
    
    .nav-brand {
        font-size: 1.25rem;
    }
    
    .main {
        padding: 1.5rem 15px;
    }
}