:root {
    --color-primary: #2d3748;
    --color-secondary: #4a5568;
    --color-accent: #4fd1c5;
    --color-accent-dark: #38b2ac;
    --color-background: #f7fafc;
    --color-surface: #ffffff;
    --color-text: #1a202c;
    --color-text-light: #718096;
    --color-border: #e2e8f0;
    --color-warning-bg: #fffaf0;
    --color-warning-border: #f6ad55;
    --font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --spacing-xs: 0.25rem;
    --spacing-sm: 0.5rem;
    --spacing-md: 1rem;
    --spacing-lg: 1.5rem;
    --spacing-xl: 2rem;
    --spacing-2xl: 3rem;
    --border-radius: 8px;
    --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-md: 0 4px 6px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px rgba(0, 0, 0, 0.1);
    --transition: 0.3s ease;
}

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

html {
    font-size: 16px;
    scroll-behavior: smooth;
}

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

.container {
    width: 100%;
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 var(--spacing-md);
}

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

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

a:focus {
    outline: 2px solid var(--color-accent);
    outline-offset: 2px;
}

.btn {
    display: inline-block;
    padding: var(--spacing-sm) var(--spacing-lg);
    border-radius: var(--border-radius);
    font-weight: 600;
    text-align: center;
    transition: all var(--transition);
    cursor: pointer;
    border: none;
}

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

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

.site-header {
    background-color: var(--color-surface);
    box-shadow: var(--shadow-sm);
    position: sticky;
    top: 0;
    z-index: 100;
}

.site-header .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: var(--spacing-md);
}

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-sm);
    font-size: 1.25rem;
    font-weight: 700;
    color: var(--color-primary);
}

.logo:hover {
    color: var(--color-accent-dark);
}

.menu-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    background: none;
    border: none;
    cursor: pointer;
    padding: var(--spacing-sm);
}

.menu-toggle span {
    display: block;
    width: 24px;
    height: 2px;
    background-color: var(--color-primary);
    transition: var(--transition);
}

.main-nav ul {
    display: flex;
    list-style: none;
    gap: var(--spacing-lg);
}

.main-nav a {
    color: var(--color-secondary);
    font-weight: 500;
    padding: var(--spacing-sm) 0;
    position: relative;
}

.main-nav a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    width: 0;
    height: 2px;
    background-color: var(--color-accent);
    transition: width var(--transition);
}

.main-nav a:hover::after,
.main-nav a[aria-current="page"]::after {
    width: 100%;
}

.main-nav a:hover,
.main-nav a[aria-current="page"] {
    color: var(--color-accent-dark);
}

.hero {
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 100%);
    color: var(--color-surface);
    padding: var(--spacing-2xl) 0;
    text-align: center;
}

.hero h1 {
    font-size: clamp(1.75rem, 5vw, 2.5rem);
    margin-bottom: var(--spacing-md);
    line-height: 1.2;
}

.hero-subtitle {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-lg);
    opacity: 0.9;
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

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

.hero .btn:hover {
    background-color: var(--color-surface);
    color: var(--color-primary);
}

main {
    flex: 1;
}

section {
    padding: var(--spacing-2xl) 0;
}

section h2 {
    font-size: 1.75rem;
    color: var(--color-primary);
    margin-bottom: var(--spacing-lg);
    text-align: center;
}

.section-intro {
    text-align: center;
    color: var(--color-text-light);
    margin-bottom: var(--spacing-xl);
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

.value-props {
    background-color: var(--color-surface);
}

.value-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: var(--spacing-lg);
}

.value-card {
    padding: var(--spacing-lg);
    border-radius: var(--border-radius);
    background-color: var(--color-background);
    text-align: center;
    transition: transform var(--transition), box-shadow var(--transition);
}

.value-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.value-icon {
    margin-bottom: var(--spacing-md);
}

.value-card h3 {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-sm);
    color: var(--color-primary);
}

.value-card p {
    color: var(--color-text-light);
    font-size: 0.9375rem;
}

.learning-path {
    background-color: var(--color-background);
}

.path-steps {
    list-style: none;
    max-width: 800px;
    margin: 0 auto;
    counter-reset: step;
}

.path-steps > li {
    display: flex;
    gap: var(--spacing-lg);
    margin-bottom: var(--spacing-lg);
    position: relative;
}

.path-steps > li:not(:last-child)::after {
    content: '';
    position: absolute;
    left: 24px;
    top: 48px;
    bottom: -var(--spacing-lg);
    width: 2px;
    background-color: var(--color-border);
}

.step-number {
    flex-shrink: 0;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background-color: var(--color-accent);
    color: var(--color-primary);
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 1.25rem;
}

.step-content {
    flex: 1;
    padding-top: var(--spacing-xs);
}

.step-content h3 {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-xs);
    color: var(--color-primary);
}

.step-content p {
    color: var(--color-text-light);
    font-size: 0.9375rem;
}

.recommended-articles {
    background-color: var(--color-surface);
}

.article-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: var(--spacing-lg);
}

.article-card {
    padding: var(--spacing-lg);
    border-radius: var(--border-radius);
    background-color: var(--color-background);
    border: 1px solid var(--color-border);
    transition: border-color var(--transition);
}

.article-card:hover {
    border-color: var(--color-accent);
}

.article-card h3 {
    font-size: 1.125rem;
    margin-bottom: var(--spacing-sm);
}

.article-card h3 a {
    color: var(--color-primary);
}

.article-card h3 a:hover {
    color: var(--color-accent-dark);
}

.article-card p {
    color: var(--color-text-light);
    font-size: 0.9375rem;
    margin-bottom: var(--spacing-md);
}

.read-more {
    font-weight: 600;
    font-size: 0.875rem;
}

.more-articles {
    text-align: center;
    margin-top: var(--spacing-xl);
}

.faq-section {
    background-color: var(--color-background);
}

.faq-list {
    max-width: 800px;
    margin: 0 auto;
}

.faq-item {
    margin-bottom: var(--spacing-md);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    overflow: hidden;
}

.faq-item dt {
    padding: var(--spacing-md);
    background-color: var(--color-surface);
    font-weight: 600;
    color: var(--color-primary);
}

.faq-item dd {
    padding: var(--spacing-md);
    background-color: var(--color-surface);
    color: var(--color-text-light);
    font-size: 0.9375rem;
    border-top: 1px solid var(--color-border);
}

.important-notice {
    background-color: var(--color-surface);
}

.notice-box {
    max-width: 800px;
    margin: 0 auto;
    padding: var(--spacing-lg);
    background-color: var(--color-warning-bg);
    border: 2px solid var(--color-warning-border);
    border-radius: var(--border-radius);
}

.notice-box h2 {
    text-align: left;
    font-size: 1.25rem;
}

.notice-box p {
    margin-bottom: var(--spacing-sm);
    font-size: 0.9375rem;
}

.notice-box .notice-last {
    margin-bottom: 0;
}

.site-footer {
    background-color: var(--color-primary);
    color: var(--color-surface);
    padding: var(--spacing-xl) 0;
    margin-top: auto;
}

.footer-nav ul,
.footer-links ul {
    list-style: none;
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: var(--spacing-md);
    margin-bottom: var(--spacing-md);
}

.footer-nav a,
.footer-links a {
    color: rgba(255, 255, 255, 0.8);
    font-size: 0.9375rem;
}

.footer-links {
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-md);
    border-bottom: 1px solid rgba(255, 255, 255, 0.1);
}

.footer-links ul {
    justify-content: center;
}

.footer-links a {
    font-size: 0.875rem;
}

.copyright {
    text-align: center;
    font-size: 0.875rem;
    opacity: 0.8;
    margin-bottom: var(--spacing-xs);
}

.age-notice {
    text-align: center;
    font-size: 0.8125rem;
    opacity: 0.6;
}

@media (max-width: 768px) {
    .menu-toggle {
        display: flex;
    }

    .main-nav {
        display: none;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background-color: var(--color-surface);
        box-shadow: var(--shadow-md);
        padding: var(--spacing-md);
    }

    .main-nav.active {
        display: block;
    }

    .main-nav ul {
        flex-direction: column;
        gap: var(--spacing-sm);
    }

    .main-nav a {
        display: block;
        padding: var(--spacing-sm);
    }

    .main-nav a::after {
        display: none;
    }

    .hero {
        padding: var(--spacing-xl) 0;
    }

    section {
        padding: var(--spacing-xl) 0;
    }

    section h2 {
        font-size: 1.5rem;
    }

    .path-steps > li {
        flex-direction: column;
        gap: var(--spacing-sm);
    }

    .path-steps > li:not(:last-child)::after {
        display: none;
    }

    .step-number {
        width: 36px;
        height: 36px;
        font-size: 1rem;
    }
}

@media (prefers-reduced-motion: reduce) {
    *, *::before, *::after {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

.page-header {
    background: linear-gradient(135deg, var(--color-primary) 0%, var(--color-secondary) 100%);
    color: var(--color-surface);
    padding: var(--spacing-2xl) 0;
    text-align: center;
}

.page-header h1 {
    font-size: clamp(1.5rem, 5vw, 2.25rem);
    margin-bottom: var(--spacing-sm);
}

.page-subtitle {
    font-size: 1.125rem;
    opacity: 0.9;
}

.article-content {
    padding: var(--spacing-2xl) 0;
}

.article-header {
    background-color: var(--color-surface);
    padding: var(--spacing-xl) 0;
    border-bottom: 1px solid var(--color-border);
    margin-bottom: var(--spacing-xl);
}

.breadcrumb ol {
    list-style: none;
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-sm);
    margin-bottom: var(--spacing-md);
    font-size: 0.875rem;
}

.breadcrumb li:not(:last-child)::after {
    content: '/';
    margin-left: var(--spacing-sm);
    color: var(--color-text-light);
}

.breadcrumb a {
    color: var(--color-accent-dark);
}

.breadcrumb li[aria-current="page"] {
    color: var(--color-text-light);
}

.article-header h1 {
    font-size: clamp(1.5rem, 4vw, 2rem);
    color: var(--color-primary);
    margin-bottom: var(--spacing-sm);
    line-height: 1.3;
}

.article-meta {
    display: flex;
    gap: var(--spacing-md);
    font-size: 0.875rem;
    color: var(--color-text-light);
}

.article-category {
    background-color: var(--color-background);
    padding: 2px 8px;
    border-radius: 4px;
}

.article-body {
    max-width: 800px;
    margin: 0 auto;
}

.article-body section {
    padding: var(--spacing-lg) 0;
}

.article-body section h2 {
    font-size: 1.5rem;
    color: var(--color-primary);
    margin-bottom: var(--spacing-md);
    text-align: left;
}

.article-body section p {
    margin-bottom: var(--spacing-md);
    color: var(--color-text);
}

.article-body section ul,
.article-body section ol {
    margin-bottom: var(--spacing-md);
    padding-left: var(--spacing-lg);
}

.article-body section li {
    margin-bottom: var(--spacing-sm);
    color: var(--color-text);
}

.article-body section dl {
    margin-bottom: var(--spacing-md);
}

.article-body section dt {
    font-weight: 600;
    color: var(--color-primary);
    margin-bottom: var(--spacing-xs);
}

.article-body section dd {
    margin-left: 0;
    margin-bottom: var(--spacing-md);
    color: var(--color-text-light);
}

.article-disclaimer {
    background-color: var(--color-warning-bg);
    border: 1px solid var(--color-warning-border);
    border-radius: var(--border-radius);
    padding: var(--spacing-lg);
    margin-top: var(--spacing-xl);
}

.article-disclaimer h2 {
    font-size: 1.125rem;
}

.about-content,
.contact-content,
.legal-content {
    padding: var(--spacing-2xl) 0;
}

.about-content article,
.legal-content article {
    max-width: 800px;
    margin: 0 auto var(--spacing-xl);
}

.about-content h2,
.legal-content h2 {
    font-size: 1.5rem;
    color: var(--color-primary);
    margin-bottom: var(--spacing-md);
}

.about-content p,
.legal-content p {
    margin-bottom: var(--spacing-md);
    color: var(--color-text);
}

.about-content ul,
.legal-content ul {
    margin-bottom: var(--spacing-md);
    padding-left: var(--spacing-lg);
}

.about-content li,
.legal-content li {
    margin-bottom: var(--spacing-sm);
    color: var(--color-text-light);
}

.effective-date {
    font-size: 0.875rem;
    color: var(--color-text-light);
    margin-bottom: var(--spacing-xl);
    text-align: center;
}

.contact-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: var(--spacing-xl);
    max-width: 1000px;
    margin: 0 auto;
}

.contact-info h2,
.contact-form-container h2 {
    font-size: 1.5rem;
    color: var(--color-primary);
    margin-bottom: var(--spacing-md);
}

.contact-method {
    margin-bottom: var(--spacing-lg);
}

.contact-method h3 {
    font-size: 1rem;
    color: var(--color-primary);
    margin-bottom: var(--spacing-xs);
}

.contact-notice {
    background-color: var(--color-warning-bg);
    border: 1px solid var(--color-warning-border);
    border-radius: var(--border-radius);
    padding: var(--spacing-md);
    margin-top: var(--spacing-lg);
}

.contact-notice h3 {
    font-size: 1rem;
    color: var(--color-primary);
    margin-bottom: var(--spacing-sm);
}

.contact-notice p {
    font-size: 0.875rem;
    color: var(--color-text-light);
}

.contact-form .form-group {
    margin-bottom: var(--spacing-md);
}

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

.contact-form input,
.contact-form select,
.contact-form textarea {
    width: 100%;
    padding: var(--spacing-sm) var(--spacing-md);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    font-family: var(--font-family);
    font-size: 1rem;
    transition: border-color var(--transition);
}

.contact-form input:focus,
.contact-form select:focus,
.contact-form textarea:focus {
    outline: none;
    border-color: var(--color-accent);
}

.contact-form textarea {
    resize: vertical;
}

.articles-list {
    padding: var(--spacing-2xl) 0;
}

.articles-container {
    max-width: 800px;
    margin: 0 auto;
}

.articles-container h2 {
    margin-bottom: var(--spacing-xl);
}

.article-item {
    padding: var(--spacing-lg);
    border: 1px solid var(--color-border);
    border-radius: var(--border-radius);
    margin-bottom: var(--spacing-md);
    background-color: var(--color-surface);
    transition: border-color var(--transition);
}

.article-item:hover {
    border-color: var(--color-accent);
}

.article-item .article-meta {
    margin-bottom: var(--spacing-sm);
}

.article-item h3 {
    font-size: 1.25rem;
    margin-bottom: var(--spacing-sm);
}

.article-item h3 a {
    color: var(--color-primary);
}

.article-item h3 a:hover {
    color: var(--color-accent-dark);
}

.article-item p {
    color: var(--color-text-light);
    margin-bottom: var(--spacing-sm);
}

.error-page {
    flex: 1;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: var(--spacing-2xl) 0;
    text-align: center;
}

.error-content h1 {
    font-size: 6rem;
    color: var(--color-accent);
    line-height: 1;
    margin-bottom: var(--spacing-sm);
}

.error-content h2 {
    font-size: 1.5rem;
    color: var(--color-primary);
    margin-bottom: var(--spacing-md);
}

.error-content p {
    color: var(--color-text-light);
    margin-bottom: var(--spacing-lg);
}

.error-actions {
    display: flex;
    gap: var(--spacing-md);
    justify-content: center;
    flex-wrap: wrap;
}

.btn-secondary {
    background-color: var(--color-surface);
    color: var(--color-primary);
    border: 2px solid var(--color-border);
}

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

@media (max-width: 768px) {
    .contact-grid {
        grid-template-columns: 1fr;
    }

    .article-body section h2 {
        font-size: 1.25rem;
    }

    .error-content h1 {
        font-size: 4rem;
    }
}