/* Base styles and CSS custom properties */

:root {
    /* Light theme colors */
    --color-bg: #ffffff;
    --color-surface: #f8f9fa;
    --color-surface-hover: #f0f1f2;
    --color-text: #1a1a1a;
    --color-text-muted: #666666;
    --color-accent: #2d5a27;
    --color-accent-hover: #3d7a37;
    --color-border: #e0e0e0;
    --color-code-bg: #f5f5f5;
    --color-overlay: rgba(0, 0, 0, 0.5);

    /* Spacing */
    --space-xs: 0.25rem;
    --space-sm: 0.5rem;
    --space-md: 1rem;
    --space-lg: 2rem;
    --space-xl: 4rem;

    /* Typography */
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    --font-mono: 'SF Mono', 'Fira Code', 'Consolas', monospace;

    /* Layout */
    --max-width: 1400px;
    --card-radius: 12px;
    --header-height: 64px;

    /* Transitions */
    --transition-fast: 150ms ease;
    --transition-normal: 250ms ease;
}

[data-theme="dark"] {
    --color-bg: #0d1117;
    --color-surface: #161b22;
    --color-surface-hover: #21262d;
    --color-text: #e6edf3;
    --color-text-muted: #8b949e;
    --color-accent: #4ade80;
    --color-accent-hover: #22c55e;
    --color-border: #30363d;
    --color-code-bg: #1e2228;
    --color-overlay: rgba(0, 0, 0, 0.7);
}

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

html {
    scroll-behavior: smooth;
}

body {
    font-family: var(--font-sans);
    font-size: 16px;
    line-height: 1.6;
    color: var(--color-text);
    background-color: var(--color-bg);
    min-height: 100vh;
    transition: background-color var(--transition-normal), color var(--transition-normal);
}

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

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

button {
    font-family: inherit;
    cursor: pointer;
    border: none;
    background: none;
}

/* Header */
.site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background-color: var(--color-bg);
    border-bottom: 1px solid var(--color-border);
    height: var(--header-height);
    transition: background-color var(--transition-normal), border-color var(--transition-normal);
}

.header-content {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--space-lg);
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-lg);
}

.logo {
    display: flex;
    align-items: baseline;
    gap: var(--space-sm);
    color: var(--color-text);
    font-weight: 700;
}

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

.logo-text {
    font-size: 1.5rem;
}

.logo-subtitle {
    font-size: 1rem;
    font-weight: 400;
    color: var(--color-text-muted);
}

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

.main-nav a {
    color: var(--color-text-muted);
    font-size: 0.9rem;
    font-weight: 500;
    padding: var(--space-sm) 0;
}

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

.theme-toggle {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: 8px;
    color: var(--color-text-muted);
    transition: background-color var(--transition-fast), color var(--transition-fast);
}

.theme-toggle:hover {
    background-color: var(--color-surface);
    color: var(--color-text);
}

.icon-moon {
    display: none;
}

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

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

/* Hero */
.hero {
    text-align: center;
    padding: var(--space-xl) var(--space-lg);
    max-width: 800px;
    margin: 0 auto;
}

.hero h1 {
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: var(--space-md);
    letter-spacing: -0.02em;
}

.hero-subtitle {
    font-size: 1.125rem;
    color: var(--color-text-muted);
    line-height: 1.7;
}

/* Filters */
.filters {
    max-width: var(--max-width);
    margin: 0 auto;
    padding: 0 var(--space-lg) var(--space-lg);
    display: flex;
    flex-direction: column;
    gap: var(--space-md);
}

.search-box {
    position: relative;
    max-width: 400px;
}

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

.search-box input {
    width: 100%;
    padding: var(--space-sm) var(--space-md) var(--space-sm) calc(var(--space-md) * 2 + 18px);
    font-size: 0.95rem;
    border: 1px solid var(--color-border);
    border-radius: 8px;
    background-color: var(--color-surface);
    color: var(--color-text);
    transition: border-color var(--transition-fast), background-color var(--transition-fast);
}

.search-box input:focus {
    outline: none;
    border-color: var(--color-accent);
}

.search-box input::placeholder {
    color: var(--color-text-muted);
}

.category-filters {
    display: flex;
    flex-wrap: wrap;
    gap: var(--space-sm);
}

.filter-btn {
    padding: var(--space-sm) var(--space-md);
    font-size: 0.85rem;
    font-weight: 500;
    color: var(--color-text-muted);
    background-color: var(--color-surface);
    border-radius: 20px;
    transition: all var(--transition-fast);
}

.filter-btn:hover {
    background-color: var(--color-surface-hover);
    color: var(--color-text);
}

.filter-btn.active {
    background-color: var(--color-accent);
    color: white;
}

/* Footer */
.site-footer {
    margin-top: var(--space-xl);
    padding: var(--space-lg);
    border-top: 1px solid var(--color-border);
    text-align: center;
    color: var(--color-text-muted);
    font-size: 0.875rem;
}

.footer-content {
    max-width: var(--max-width);
    margin: 0 auto;
}

.footer-content p {
    margin-bottom: var(--space-xs);
}

.version {
    opacity: 0.6;
}

/* Utility classes */
.loading {
    text-align: center;
    padding: var(--space-xl);
    color: var(--color-text-muted);
}

.no-results {
    text-align: center;
    padding: var(--space-xl);
    color: var(--color-text-muted);
}

[hidden] {
    display: none !important;
}