/* ===================================
   CSS Reset & Base Styles
   =================================== */

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

/* ===================================
   CSS Custom Properties (Theming)
   =================================== */

:root {
    /* Colors - Light Mode */
    --color-primary: #FFD700;
    --color-primary-dark: #E6C200;
    --color-primary-light: #FFF4CC;

    --color-background: #FAFAFA;
    --color-surface: #FFFFFF;
    --color-surface-elevated: #FFFFFF;

    --color-text-primary: #1A1A1A;
    --color-text-secondary: #4A4A4A;
    --color-text-tertiary: #6B6B6B;

    --color-border: #E0E0E0;
    --color-border-hover: #D0D0D0;

    --color-accent: #2563EB;
    --color-success: #059669;
    --color-warning: #D97706;
    --color-error: #DC2626;

    /* 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), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);

    /* Typography */
    --font-sans: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    --font-serif: Georgia, Cambria, "Times New Roman", Times, serif;

    /* Spacing */
    --spacing-xs: 0.5rem;
    --spacing-sm: 1rem;
    --spacing-md: 1.5rem;
    --spacing-lg: 2rem;
    --spacing-xl: 3rem;
    --spacing-2xl: 4rem;

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

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-base: 250ms ease;
    --transition-slow: 350ms ease;
}

/* Dark Mode */
[data-theme="dark"] {
    --color-background: #0F0F0F;
    --color-surface: #1A1A1A;
    --color-surface-elevated: #242424;

    --color-text-primary: #F5F5F5;
    --color-text-secondary: #D4D4D4;
    --color-text-tertiary: #A3A3A3;

    --color-border: #2A2A2A;
    --color-border-hover: #3A3A3A;

    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.4);
    --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4), 0 2px 4px -1px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.4), 0 4px 6px -2px rgba(0, 0, 0, 0.3);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.4), 0 10px 10px -5px rgba(0, 0, 0, 0.3);
}

/* ===================================
   Base Typography
   =================================== */

body {
    font-family: var(--font-sans);
    font-size: 16px;
    line-height: 1.6;
    color: var(--color-text-primary);
    background-color: var(--color-background);
    transition: background-color var(--transition-base), color var(--transition-base);
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

h1, h2, h3, h4, h5, h6 {
    font-weight: 600;
    line-height: 1.2;
    color: var(--color-text-primary);
}

h1 { font-size: 2.5rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }

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

a:hover {
    color: var(--color-primary-dark);
}

/* ===================================
   Layout & Container
   =================================== */

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

/* ===================================
   Header
   =================================== */

.site-header {
    background-color: var(--color-surface);
    border-bottom: 1px solid var(--color-border);
    padding: var(--spacing-sm) 0;
    position: sticky;
    top: 0;
    z-index: 1000;
    box-shadow: var(--shadow-sm);
    transition: all var(--transition-base);
}

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

.logo {
    display: flex;
    align-items: center;
    gap: var(--spacing-xs);
    font-size: 1.25rem;
    color: var(--color-text-primary);
    text-decoration: none;
}

.logo strong {
    font-weight: 700;
}

.logo-text {
    font-weight: 400;
}

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

.main-nav a {
    color: var(--color-text-secondary);
    font-weight: 500;
    transition: color var(--transition-fast);
}

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

.theme-toggle {
    background: none;
    border: 1px solid var(--color-border);
    border-radius: var(--radius-md);
    padding: var(--spacing-xs);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    color: var(--color-text-secondary);
    transition: all var(--transition-fast);
}

.theme-toggle:hover {
    background-color: var(--color-surface-elevated);
    border-color: var(--color-primary);
    color: var(--color-primary);
}

.theme-toggle .moon-icon {
    display: none;
}

[data-theme="dark"] .theme-toggle .sun-icon {
    display: none;
}

[data-theme="dark"] .theme-toggle .moon-icon {
    display: block;
}

/* ===================================
   Hero Section
   =================================== */

.hero {
    background: linear-gradient(135deg, var(--color-surface) 0%, var(--color-primary-light) 100%);
    padding: var(--spacing-2xl) 0;
    text-align: center;
    border-bottom: 1px solid var(--color-border);
}

[data-theme="dark"] .hero {
    background: linear-gradient(135deg, var(--color-surface) 0%, #332800 100%);
}

.hero-title {
    font-size: clamp(2rem, 5vw, 3.5rem);
    margin-bottom: var(--spacing-sm);
    background: linear-gradient(135deg, var(--color-text-primary) 0%, var(--color-primary-dark) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.25rem;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-xl);
    max-width: 600px;
    margin-left: auto;
    margin-right: auto;
}

/* Search Bar */
.search-container {
    position: relative;
    max-width: 600px;
    margin: 0 auto;
}

.search-icon {
    position: absolute;
    left: var(--spacing-md);
    top: 50%;
    transform: translateY(-50%);
    color: var(--color-text-tertiary);
    pointer-events: none;
}

.search-input {
    width: 100%;
    padding: var(--spacing-md) var(--spacing-md) var(--spacing-md) 3.5rem;
    font-size: 1rem;
    border: 2px solid var(--color-border);
    border-radius: var(--radius-lg);
    background-color: var(--color-surface);
    color: var(--color-text-primary);
    transition: all var(--transition-fast);
    font-family: var(--font-sans);
}

.search-input:focus {
    outline: none;
    border-color: var(--color-primary);
    box-shadow: 0 0 0 3px rgba(255, 215, 0, 0.1);
}

.search-results {
    position: absolute;
    top: calc(100% + var(--spacing-xs));
    left: 0;
    right: 0;
    background-color: var(--color-surface-elevated);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-xl);
    max-height: 400px;
    overflow-y: auto;
    z-index: 100;
}

.search-result-item {
    padding: var(--spacing-md);
    border-bottom: 1px solid var(--color-border);
    cursor: pointer;
    transition: background-color var(--transition-fast);
}

.search-result-item:last-child {
    border-bottom: none;
}

.search-result-item:hover {
    background-color: var(--color-primary-light);
}

[data-theme="dark"] .search-result-item:hover {
    background-color: rgba(255, 215, 0, 0.1);
}

.search-result-item h4 {
    font-family: var(--font-serif);
    font-size: 1.1rem;
    margin-bottom: var(--spacing-xs);
    color: var(--color-text-primary);
}

.search-result-meta {
    display: flex;
    gap: var(--spacing-sm);
    font-size: 0.875rem;
    color: var(--color-text-tertiary);
    margin-bottom: var(--spacing-xs);
}

.search-result-category {
    color: var(--color-primary-dark);
    font-weight: 600;
}

.no-results {
    padding: var(--spacing-lg);
    text-align: center;
    color: var(--color-text-secondary);
}

/* ===================================
   Sections
   =================================== */

.browse-section,
.featured-section,
.about-section {
    padding: var(--spacing-2xl) 0;
}

.section-title {
    text-align: center;
    margin-bottom: var(--spacing-sm);
}

.section-subtitle {
    text-align: center;
    color: var(--color-text-secondary);
    margin-bottom: var(--spacing-xl);
    font-size: 1.1rem;
}

/* ===================================
   Situations Grid
   =================================== */

.situations-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: var(--spacing-md);
}

.situation-card {
    background-color: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    text-align: center;
    cursor: pointer;
    transition: all var(--transition-base);
    box-shadow: var(--shadow-sm);
}

.situation-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
    border-color: var(--color-primary);
}

.situation-icon {
    font-size: 2.5rem;
    margin-bottom: var(--spacing-sm);
}

.situation-card h3 {
    font-size: 1.1rem;
    margin-bottom: var(--spacing-xs);
}

.situation-card p {
    color: var(--color-text-secondary);
    font-size: 0.9rem;
}

/* ===================================
   Rules Grid
   =================================== */

.rules-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(320px, 1fr));
    gap: var(--spacing-lg);
}

.rule-card {
    background-color: var(--color-surface);
    border: 1px solid var(--color-border);
    border-radius: var(--radius-lg);
    padding: var(--spacing-lg);
    box-shadow: var(--shadow-md);
    transition: all var(--transition-base);
    display: flex;
    flex-direction: column;
}

.rule-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-xl);
    border-color: var(--color-primary);
}

.rule-header {
    margin-bottom: var(--spacing-md);
}

.rule-category {
    display: inline-block;
    background-color: var(--color-primary-light);
    color: var(--color-primary-dark);
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    font-weight: 600;
    margin-bottom: var(--spacing-sm);
}

[data-theme="dark"] .rule-category {
    background-color: rgba(255, 215, 0, 0.15);
    color: var(--color-primary);
}

.rule-title {
    font-family: var(--font-serif);
    font-size: 1.5rem;
    line-height: 1.4;
    margin-bottom: var(--spacing-sm);
    color: var(--color-text-primary);
}

.rule-situation {
    color: var(--color-text-tertiary);
    font-size: 0.9rem;
    font-style: italic;
    margin-bottom: var(--spacing-md);
}

.rule-excerpt {
    color: var(--color-text-secondary);
    flex-grow: 1;
    margin-bottom: var(--spacing-md);
}

.rule-link {
    display: inline-flex;
    align-items: center;
    gap: var(--spacing-xs);
    color: var(--color-primary-dark);
    font-weight: 600;
    transition: gap var(--transition-fast);
}

.rule-link:hover {
    gap: var(--spacing-sm);
}

/* ===================================
   Rule Page Styles
   =================================== */

.rule-page {
    max-width: 800px;
    margin: 0 auto;
    padding: var(--spacing-xl) var(--spacing-md);
}

.breadcrumb {
    display: flex;
    gap: var(--spacing-xs);
    align-items: center;
    margin-bottom: var(--spacing-lg);
    font-size: 0.9rem;
    color: var(--color-text-tertiary);
}

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

.breadcrumb-separator {
    color: var(--color-text-tertiary);
}

.rule-page-header {
    margin-bottom: var(--spacing-xl);
}

.rule-page-title {
    font-family: var(--font-serif);
    font-size: clamp(2rem, 5vw, 3rem);
    line-height: 1.3;
    margin-bottom: var(--spacing-md);
}

.importance-box {
    background: linear-gradient(135deg, var(--color-primary-light) 0%, var(--color-surface) 100%);
    border-left: 4px solid var(--color-primary);
    padding: var(--spacing-lg);
    border-radius: var(--radius-md);
    margin-bottom: var(--spacing-xl);
}

[data-theme="dark"] .importance-box {
    background: linear-gradient(135deg, rgba(255, 215, 0, 0.1) 0%, var(--color-surface) 100%);
}

.importance-box h3 {
    color: var(--color-primary-dark);
    margin-bottom: var(--spacing-sm);
}

.rule-section {
    margin-bottom: var(--spacing-xl);
}

.rule-section h2 {
    margin-bottom: var(--spacing-md);
    padding-bottom: var(--spacing-sm);
    border-bottom: 2px solid var(--color-border);
}

.rule-section p {
    line-height: 1.8;
    color: var(--color-text-secondary);
}

.tags {
    display: flex;
    flex-wrap: wrap;
    gap: var(--spacing-xs);
    margin-top: var(--spacing-lg);
}

.tag {
    background-color: var(--color-surface-elevated);
    border: 1px solid var(--color-border);
    padding: 0.25rem 0.75rem;
    border-radius: var(--radius-sm);
    font-size: 0.875rem;
    color: var(--color-text-secondary);
    transition: all var(--transition-fast);
}

.tag:hover {
    background-color: var(--color-primary-light);
    border-color: var(--color-primary);
    color: var(--color-primary-dark);
}

.related-rules {
    background-color: var(--color-surface-elevated);
    padding: var(--spacing-lg);
    border-radius: var(--radius-lg);
    margin-top: var(--spacing-xl);
}

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

.related-rules-list {
    list-style: none;
}

.related-rules-list li {
    margin-bottom: var(--spacing-sm);
}

.related-rules-list a {
    display: block;
    padding: var(--spacing-sm);
    border-radius: var(--radius-sm);
    transition: background-color var(--transition-fast);
}

.related-rules-list a:hover {
    background-color: var(--color-primary-light);
}

[data-theme="dark"] .related-rules-list a:hover {
    background-color: rgba(255, 215, 0, 0.1);
}

/* ===================================
   About Section
   =================================== */

.about-content {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.about-content p {
    color: var(--color-text-secondary);
    font-size: 1.1rem;
    margin-bottom: var(--spacing-md);
    line-height: 1.8;
}

/* ===================================
   Footer
   =================================== */

.site-footer {
    background-color: var(--color-surface);
    border-top: 1px solid var(--color-border);
    padding: var(--spacing-xl) 0 var(--spacing-lg);
    margin-top: var(--spacing-2xl);
}

.footer-content {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: var(--spacing-xl);
    margin-bottom: var(--spacing-lg);
}

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

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

.footer-section ul {
    list-style: none;
}

.footer-section ul li {
    margin-bottom: var(--spacing-xs);
}

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

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

.footer-bottom {
    text-align: center;
    padding-top: var(--spacing-lg);
    border-top: 1px solid var(--color-border);
    color: var(--color-text-tertiary);
    font-size: 0.9rem;
}

/* ===================================
   Buttons
   =================================== */

.btn-primary {
    display: inline-block;
    padding: 1rem 2rem;
    background: linear-gradient(135deg, var(--color-primary), var(--color-primary-dark));
    color: var(--color-text-primary);
    text-decoration: none;
    border-radius: var(--radius-lg);
    font-weight: 600;
    font-size: 1.1rem;
    transition: transform var(--transition-fast), box-shadow var(--transition-fast);
    box-shadow: var(--shadow-md);
    border: none;
    cursor: pointer;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-lg);
    color: var(--color-text-primary);
}

.btn-primary:active {
    transform: translateY(0);
}

/* ===================================
   Responsive Design
   =================================== */

@media (max-width: 768px) {
    .main-nav {
        display: none;
    }

    h1 { font-size: 2rem; }
    h2 { font-size: 1.75rem; }

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

    .rules-grid {
        grid-template-columns: 1fr;
    }

    .situations-grid {
        grid-template-columns: 1fr;
    }

    .footer-content {
        grid-template-columns: 1fr;
    }
}

/* ===================================
   Utilities
   =================================== */

.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border-width: 0;
}