:root {
    /* Colors */
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --primary-light: #818cf8;
    --secondary: #8b5cf6;
    --success: #10b981;
    --error: #ef4444;
    --warning: #f59e0b;

    /* Neutrals */
    --bg-primary: #ffffff;
    --bg-secondary: #f9fafb;
    --bg-tertiary: #f3f4f6;
    --border: #e5e7eb;
    --text-primary: #111827;
    --text-secondary: #6b7280;
    --text-tertiary: #9ca3af;

    /* Dark mode */
    --dark-bg-primary: #0f172a;
    --dark-bg-secondary: #1e293b;
    --dark-bg-tertiary: #334155;
    --dark-border: #475569;
    --dark-text-primary: #f1f5f9;
    --dark-text-secondary: #cbd5e1;
    --dark-text-tertiary: #94a3b8;

    /* Spacing */
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;

    /* Typography */
    --font-sans: 'Noto Sans JP', -apple-system, BlinkMacSystemFont, sans-serif;
    --font-mono: 'JetBrains Mono', 'Courier New', monospace;

    /* Borders */
    --radius-sm: 0.375rem;
    --radius-md: 0.5rem;
    --radius-lg: 0.75rem;
    --radius-xl: 1rem;

    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1);
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg-primary: var(--dark-bg-primary);
        --bg-secondary: var(--dark-bg-secondary);
        --bg-tertiary: var(--dark-bg-tertiary);
        --border: var(--dark-border);
        --text-primary: var(--dark-text-primary);
        --text-secondary: var(--dark-text-secondary);
        --text-tertiary: var(--dark-text-tertiary);
    }
}

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

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

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-lg);
}

/* Header */
.site-header {
    background: var(--bg-primary);
    border-bottom: 1px solid var(--border);
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(10px);
    background: rgba(255, 255, 255, 0.8);
}

@media (prefers-color-scheme: dark) {
    .site-header {
        background: rgba(15, 23, 42, 0.8);
    }
}

.header-content {
    display: flex;
    align-items: center;
    gap: var(--spacing-xl);
    padding: var(--spacing-md) 0;
}

.site-logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    text-decoration: none;
    color: var(--text-primary);
    font-weight: 700;
    font-size: 1.25rem;
    transition: color 0.2s;
}

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

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

.main-nav {
    display: flex;
    gap: var(--spacing-lg);
    flex: 1;
}

.nav-link {
    color: var(--text-secondary);
    text-decoration: none;
    font-weight: 500;
    transition: color 0.2s;
    position: relative;
}

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

.nav-link::after {
    content: '';
    position: absolute;
    bottom: -0.5rem;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--primary);
    transform: scaleX(0);
    transition: transform 0.2s;
}

.nav-link:hover::after {
    transform: scaleX(1);
}

.header-actions {
    display: flex;
    align-items: center;
    gap: var(--spacing-md);
}

.search-form {
    position: relative;
}

.search-input {
    padding: var(--spacing-sm) var(--spacing-md);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    background: var(--bg-secondary);
    color: var(--text-primary);
    font-family: var(--font-sans);
    font-size: 0.875rem;
    width: 200px;
    transition: all 0.2s;
}

.search-input:focus {
    outline: none;
    border-color: var(--primary);
    width: 300px;
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

/* User Menu */
.user-menu {
    position: relative;
}

.user-menu-trigger {
    background: none;
    border: none;
    cursor: pointer;
    padding: 0;
}

.user-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    object-fit: cover;
    border: 2px solid var(--border);
    transition: border-color 0.2s;
}

.user-avatar-placeholder {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    color: white;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.125rem;
}

.user-menu-trigger:hover .user-avatar {
    border-color: var(--primary);
}

.user-menu-dropdown {
    position: absolute;
    top: calc(100% + var(--spacing-sm));
    right: 0;
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
    min-width: 200px;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: all 0.2s;
}

.user-menu:hover .user-menu-dropdown {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.dropdown-item {
    display: block;
    padding: var(--spacing-sm) var(--spacing-md);
    color: var(--text-primary);
    text-decoration: none;
    transition: background 0.2s;
}

.dropdown-item:hover {
    background: var(--bg-secondary);
}

.dropdown-divider {
    border: none;
    border-top: 1px solid var(--border);
    margin: var(--spacing-sm) 0;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) var(--spacing-lg);
    border: none;
    border-radius: var(--radius-md);
    font-family: var(--font-sans);
    font-size: 0.875rem;
    font-weight: 500;
    text-decoration: none;
    cursor: pointer;
    transition: all 0.2s;
}

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

.btn-primary:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

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

.btn-secondary:hover {
    background: var(--bg-tertiary);
}

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

.btn-danger:hover {
    background: #d32f2f;
    transform: translateY(-1px);
    box-shadow: var(--shadow-md);
}

.btn-danger-outline {
    background: transparent;
    color: var(--error);
    border: 1px solid var(--error);
}

.btn-danger-outline:hover {
    background: rgba(239, 68, 68, 0.1);
}

.btn-block {
    width: 100%;
    justify-content: center;
}

/* Flash Messages */
.flash-message {
    padding: var(--spacing-md);
    margin-bottom: var(--spacing-lg);
    border-radius: var(--radius-md);
    animation: slideDown 0.3s ease-out;
}

@keyframes slideDown {
    from {
        opacity: 0;
        transform: translateY(-20px);
    }

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

.flash-success {
    background: rgba(16, 185, 129, 0.1);
    color: var(--success);
    border: 1px solid rgba(16, 185, 129, 0.2);
}

.flash-error {
    background: rgba(239, 68, 68, 0.1);
    color: var(--error);
    border: 1px solid rgba(239, 68, 68, 0.2);
}

/* Main Content */
.site-main {
    flex: 1;
    padding: var(--spacing-2xl) 0;
}

/* Cards */
.card {
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-xl);
    box-shadow: var(--shadow-sm);
    transition: all 0.2s;
}

.card:hover {
    box-shadow: var(--shadow-md);
    transform: translateY(-2px);
}

.card-title {
    font-size: 1.5rem;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
}

.card-meta {
    color: var(--text-secondary);
    font-size: 0.875rem;
    margin-bottom: var(--spacing-md);
}

/* Forms */
.form-group {
    margin-bottom: var(--spacing-lg);
}

.form-group label {
    display: block;
    margin-bottom: var(--spacing-sm);
    font-weight: 500;
    color: var(--text-primary);
}

.form-group input[type="text"],
.form-group input[type="email"],
.form-group input[type="password"],
.form-group textarea,
.form-group select {
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-md);
    border: 1px solid var(--border);
    border-radius: var(--radius-md);
    background: var(--bg-secondary);
    color: var(--text-primary);
    font-family: var(--font-sans);
    font-size: 1rem;
    transition: all 0.2s;
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.1);
}

.form-group textarea {
    min-height: 200px;
    resize: vertical;
    font-family: var(--font-mono);
}

.form-group small {
    display: block;
    margin-top: var(--spacing-xs);
    color: var(--text-tertiary);
    font-size: 0.875rem;
}

/* Login Page */
.login-container {
    max-width: 500px;
    margin: 0 auto;
    padding: var(--spacing-2xl);
}

.login-card {
    background: var(--bg-primary);
    border: 1px solid var(--border);
    border-radius: var(--radius-xl);
    padding: var(--spacing-2xl);
    box-shadow: var(--shadow-xl);
}

.login-card h1 {
    text-align: center;
    margin-bottom: var(--spacing-sm);
    background: linear-gradient(135deg, var(--primary), var(--secondary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.login-description {
    text-align: center;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-xl);
}

.login-info {
    margin-top: var(--spacing-xl);
    padding-top: var(--spacing-xl);
    border-top: 1px solid var(--border);
}

.login-info h3 {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-md);
}

.login-info ul {
    list-style: none;
    padding-left: 0;
}

.login-info li {
    padding-left: 1.5rem;
    position: relative;
    margin-bottom: var(--spacing-sm);
    color: var(--text-secondary);
}

.login-info li::before {
    content: '✓';
    position: absolute;
}

.markdown-content h1,
.markdown-content h2,
.markdown-content h3,
.markdown-content h4 {
    margin-top: var(--spacing-xl);
    margin-bottom: var(--spacing-md);
    font-weight: 700;
    color: var(--text-primary);
}

.markdown-content h1 {
    font-size: 2rem;
    border-bottom: 2px solid var(--border);
    padding-bottom: var(--spacing-sm);
}

.markdown-content h2 {
    font-size: 1.5rem;
}

.markdown-content p {
    margin-bottom: var(--spacing-md);
}

.markdown-content code {
    background: var(--bg-secondary);
    padding: 0.125rem 0.375rem;
    border-radius: var(--radius-sm);
    font-family: var(--font-mono);
    font-size: 0.875rem;
}

.markdown-content pre {
    background: var(--bg-secondary);
    padding: var(--spacing-md);
    border-radius: var(--radius-md);
    overflow-x: auto;
    margin-bottom: var(--spacing-md);
}

.markdown-content pre code {
    background: none;
    padding: 0;
}

.markdown-content blockquote {
    border-left: 4px solid var(--primary);
    padding-left: var(--spacing-md);
    margin: var(--spacing-md) 0;
    color: var(--text-secondary);
    font-style: italic;
}

.markdown-content a {
    color: var(--primary);
    text-decoration: none;
    transition: color 0.2s;
}

.markdown-content a:hover {
    color: var(--primary-dark);
    text-decoration: underline;
}

/* Infobox */
.infobox {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    margin: var(--spacing-lg) 0;
    float: right;
    width: 300px;
    margin-left: var(--spacing-lg);
}

.infobox-title {
    font-size: 1.25rem;
    font-weight: 700;
    margin-bottom: var(--spacing-md);
    text-align: center;
}

.infobox-image img {
    width: 100%;
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-sm);
}

.infobox-caption {
    text-align: center;
    font-size: 0.875rem;
    color: var(--text-secondary);
    margin-bottom: var(--spacing-md);
}

.infobox-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-sm);
    padding: var(--spacing-sm) 0;
    border-top: 1px solid var(--border);
}

.infobox-field {
    font-weight: 500;
}

.infobox-value {
    color: var(--text-secondary);
}

/* Bibliography */
.bibliography {
    margin-top: var(--spacing-2xl);
    padding-top: var(--spacing-xl);
    border-top: 2px solid var(--border);
}

.bibliography h3 {
    margin-bottom: var(--spacing-md);
}

.citation-list {
    list-style-position: outside;
    padding-left: var(--spacing-xl);
}

.citation-item {
    margin-bottom: var(--spacing-md);
    line-height: 1.6;
}

.citation-link {
    color: var(--primary);
    margin-left: var(--spacing-sm);
}

/* Footer */
.site-footer {
    background: var(--bg-secondary);
    border-top: 1px solid var(--border);
    padding: var(--spacing-2xl) 0 var(--spacing-lg);
    margin-top: auto;
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-xl);
}

.footer-section h3,
.footer-section h4 {
    margin-bottom: var(--spacing-md);
    color: var(--text-primary);
}

.footer-section p {
    color: var(--text-secondary);
    line-height: 1.6;
}

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

.footer-links li {
    margin-bottom: var(--spacing-sm);
}

.footer-links a {
    color: var(--text-secondary);
    text-decoration: none;
    transition: color 0.2s;
}

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

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-lg);
    border-top: 1px solid var(--border);
    color: var(--text-tertiary);
    font-size: 0.875rem;
}

/* Responsive */
@media (max-width: 768px) {
    .header-content {
        flex-wrap: wrap;
    }

    .main-nav {
        order: 3;
        width: 100%;
        justify-content: center;
    }

    .search-input {
        width: 150px;
    }

    .search-input:focus {
        width: 200px;
    }

    .infobox {
        float: none;
        width: 100%;
        margin-left: 0;
    }
}