:root {
    --font-sans: 'Outfit', 'Plus Jakarta Sans', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    --font-mono: 'Fira Code', 'JetBrains Mono', source-code-pro, Menlo, Monaco, Consolas, "Courier New", monospace;
    
    /* Theme Colors (Premium Dark Theme by Default) */
    --bg-main: #0b0f19;
    --bg-header: radial-gradient(circle at top center, #1e293b 0%, #0b0f19 70%);
    --bg-card: rgba(17, 24, 39, 0.7);
    --bg-card-hover: rgba(30, 41, 59, 0.7);
    --bg-modal: #111827;
    --bg-code: #1e293b;
    
    --accent: #3b82f6;
    --accent-rgb: 59, 130, 246;
    --accent-glow: rgba(59, 130, 246, 0.15);
    --accent-gradient: linear-gradient(135deg, #3b82f6 0%, #6366f1 100%);
    
    --text-primary: #f3f4f6;
    --text-secondary: #9ca3af;
    --text-muted: #6b7280;
    
    --border: rgba(255, 255, 255, 0.08);
    --border-hover: rgba(59, 130, 246, 0.3);
    
    /* Category Colors */
    --creational: #f43f5e;
    --creational-bg: rgba(244, 63, 94, 0.1);
    --structural: #3b82f6;
    --structural-bg: rgba(59, 130, 246, 0.1);
    --behavioral: #10b981;
    --behavioral-bg: rgba(16, 185, 129, 0.1);
    --architectural: #f59e0b;
    --architectural-bg: rgba(245, 158, 11, 0.1);
    
    /* Transitions */
    --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

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

body {
    font-family: var(--font-sans);
    background-color: var(--bg-main);
    color: var(--text-primary);
    line-height: 1.6;
    min-height: 100vh;
    overflow-x: hidden;
}

/* Custom Scrollbars */
::-webkit-scrollbar {
    width: 10px;
    height: 10px;
}
::-webkit-scrollbar-track {
    background: var(--bg-main);
}
::-webkit-scrollbar-thumb {
    background: #1e293b;
    border-radius: 5px;
}
::-webkit-scrollbar-thumb:hover {
    background: #334155;
}

/* Header & Intro */
header {
    background: var(--bg-header);
    border-bottom: 1px solid var(--border);
    position: relative;
    padding: 3rem 0;
}

header::after {
    content: '';
    position: absolute;
    bottom: -1px;
    left: 0;
    width: 100%;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--border), transparent);
}

.header-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
}

.logo {
    display: flex;
    align-items: center;
    font-size: 1.6rem;
    font-weight: 800;
    letter-spacing: -0.04em;
    color: var(--text-primary);
    text-decoration: none;
    margin-bottom: 2rem;
    background: linear-gradient(135deg, #ffffff 50%, #9ca3af 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.logo-dot {
    width: 8px;
    height: 8px;
    background-color: var(--accent);
    border-radius: 50%;
    margin-right: 8px;
    display: inline-block;
    box-shadow: 0 0 12px var(--accent);
}

h1 {
    font-size: 2.75rem;
    font-weight: 800;
    letter-spacing: -0.04em;
    line-height: 1.15;
    margin-bottom: 0.75rem;
    max-width: 800px;
}

.subtitle {
    font-size: 1.25rem;
    color: var(--text-secondary);
    margin-bottom: 2.5rem;
    max-width: 650px;
    font-weight: 400;
}

/* Search Bar */
.search-container {
    width: 100%;
    max-width: 650px;
    margin-bottom: 2rem;
}

.search-wrapper {
    position: relative;
    width: 100%;
}

.search-icon {
    position: absolute;
    left: 1.25rem;
    top: 50%;
    transform: translateY(-50%);
    width: 1.25rem;
    height: 1.25rem;
    color: var(--text-muted);
    pointer-events: none;
    transition: var(--transition);
}

#search-bar {
    width: 100%;
    padding: 1.1rem 1.25rem 1.1rem 3.25rem;
    font-size: 1.05rem;
    color: var(--text-primary);
    background: rgba(15, 23, 42, 0.6);
    border: 1px solid var(--border);
    border-radius: 12px;
    outline: none;
    transition: var(--transition);
    font-family: var(--font-sans);
    backdrop-filter: blur(8px);
}

#search-bar:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 4px var(--accent-glow);
    background: rgba(15, 23, 42, 0.8);
}

#search-bar:focus + .search-icon {
    color: var(--accent);
}

/* Categories Tabs */
.tabs {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    justify-content: center;
    margin-top: 1rem;
}

.tab-btn {
    background: transparent;
    border: 1px solid var(--border);
    color: var(--text-secondary);
    padding: 0.6rem 1.2rem;
    font-size: 0.95rem;
    font-weight: 500;
    border-radius: 9999px;
    cursor: pointer;
    transition: var(--transition);
    font-family: var(--font-sans);
}

.tab-btn:hover {
    border-color: rgba(255, 255, 255, 0.2);
    color: var(--text-primary);
    background: rgba(255, 255, 255, 0.03);
}

.tab-btn.active {
    background: var(--accent-gradient);
    border-color: transparent;
    color: #ffffff;
    box-shadow: 0 4px 14px rgba(59, 130, 246, 0.25);
}

/* Main Layout & Grid */
main {
    max-width: 1200px;
    margin: 0 auto;
    padding: 4rem 2rem;
}

.grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
    transition: var(--transition);
}

@media (min-width: 640px) {
    .grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

@media (min-width: 1024px) {
    .grid {
        grid-template-columns: repeat(3, 1fr);
    }
}

/* Cards */
.card {
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-radius: 16px;
    padding: 2rem;
    display: flex;
    flex-direction: column;
    justify-content: space-between;
    transition: var(--transition);
    cursor: pointer;
    backdrop-filter: blur(12px);
    position: relative;
    overflow: hidden;
}

.card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 4px;
    background: transparent;
    transition: var(--transition);
}

.card:hover {
    background: var(--bg-card-hover);
    border-color: var(--border-hover);
    transform: translateY(-5px);
    box-shadow: 0 12px 30px rgba(0, 0, 0, 0.2);
}

/* Hover Accent Indicators */
.card[data-category="creational"]:hover::before { background: var(--creational); }
.card[data-category="structural"]:hover::before { background: var(--structural); }
.card[data-category="behavioral"]:hover::before { background: var(--behavioral); }
.card[data-category="architectural"]:hover::before { background: var(--architectural); }

.card-header {
    margin-bottom: 1.25rem;
}

.top-category-badge {
    display: inline-block;
    padding: 0.35rem 0.85rem;
    font-size: 0.8rem;
    font-weight: 600;
    border-radius: 9999px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    background: rgba(59, 130, 246, 0.15);
    color: var(--accent);
    border: 1px solid rgba(59, 130, 246, 0.3);
}

.category-badge {
    display: inline-block;
    padding: 0.25rem 0.75rem;
    font-size: 0.75rem;
    font-weight: 600;
    border-radius: 9999px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.category-badge.creational { color: var(--creational); background: var(--creational-bg); }
.category-badge.structural { color: var(--structural); background: var(--structural-bg); }
.category-badge.behavioral { color: var(--behavioral); background: var(--behavioral-bg); }
.category-badge.architectural { color: var(--architectural); background: var(--architectural-bg); }

.card h3 {
    font-size: 1.4rem;
    font-weight: 700;
    margin-bottom: 0.75rem;
    color: var(--text-primary);
    letter-spacing: -0.02em;
}

.card p {
    font-size: 0.95rem;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.card-footer {
    display: flex;
    justify-content: flex-start;
    align-items: center;
}

.explore-link {
    font-size: 0.9rem;
    font-weight: 600;
    color: var(--accent);
    transition: var(--transition);
}

.card:hover .explore-link {
    color: #ffffff;
    transform: translateX(4px);
}

/* Helpers */
.hidden {
    display: none !important;
}

/* No Results State */
#no-results {
    width: 100%;
    display: flex;
    justify-content: center;
    padding: 5rem 2rem;
}

.no-results-content {
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
    max-width: 400px;
}

.no-results-icon {
    width: 4rem;
    height: 4rem;
    color: var(--text-muted);
    margin-bottom: 1.5rem;
}

.no-results-content p {
    font-size: 1.15rem;
    color: var(--text-secondary);
    margin-bottom: 1.5rem;
}

#clear-search-btn {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border);
    color: var(--text-primary);
    padding: 0.65rem 1.25rem;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 500;
    transition: var(--transition);
    font-family: var(--font-sans);
}

#clear-search-btn:hover {
    background: rgba(255, 255, 255, 0.1);
    border-color: var(--text-muted);
}

/* Footer */
footer {
    border-top: 1px solid var(--border);
    padding: 3rem 0;
    margin-top: 5rem;
    background: rgba(11, 15, 25, 0.9);
}

.footer-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
    text-align: center;
    color: var(--text-muted);
    font-size: 0.9rem;
}

/* Modal */
.modal {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    z-index: 1000;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 1.5rem;
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease;
}

.modal:not(.hidden) {
    opacity: 1;
    pointer-events: auto;
}

.modal-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(3, 7, 18, 0.75);
    backdrop-filter: blur(12px);
}

.modal-container {
    position: relative;
    background: var(--bg-modal);
    border: 1px solid var(--border);
    border-radius: 20px;
    width: 100%;
    max-width: 1100px;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.5);
    z-index: 1001;
    transform: scale(0.95) translateY(20px);
    transition: transform 0.3s cubic-bezier(0.34, 1.56, 0.64, 1);
}

.modal:not(.hidden) .modal-container {
    transform: scale(1) translateY(0);
}

.modal-close {
    position: absolute;
    top: 1.25rem;
    right: 1.25rem;
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border);
    border-radius: 50%;
    width: 2.25rem;
    height: 2.25rem;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    color: var(--text-secondary);
    transition: var(--transition);
    z-index: 10;
}

.modal-close:hover {
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-primary);
    transform: rotate(90deg);
}

.modal-close svg {
    width: 1.25rem;
    height: 1.25rem;
}

.modal-content {
    padding: 3rem;
}

.modal-header {
    margin-bottom: 2rem;
    border-bottom: 1px solid var(--border);
    padding-bottom: 1.5rem;
}

.modal-header .category-badge {
    margin-bottom: 0.75rem;
}

.modal-header h2 {
    font-size: 2.25rem;
    font-weight: 800;
    letter-spacing: -0.03em;
    color: var(--text-primary);
    margin-bottom: 0.5rem;
}

.modal-tagline {
    font-size: 1.15rem;
    color: var(--text-secondary);
    max-width: 800px;
}

/* Modal Grid Details vs Code */
.modal-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 2.5rem;
}

@media (min-width: 1024px) {
    .modal-grid {
        grid-template-columns: 1.1fr 0.9fr;
    }
}

.modal-details-col {
    display: flex;
    flex-direction: column;
    gap: 2rem;
}

.modal-section h4 {
    font-size: 1.1rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-secondary);
    margin-bottom: 0.75rem;
}

.modal-section p {
    color: var(--text-secondary);
    font-size: 1.05rem;
    line-height: 1.6;
}

.use-case-box {
    background: rgba(255, 255, 255, 0.02);
    border-left: 4px solid var(--accent);
    padding: 1.25rem;
    border-radius: 0 12px 12px 0;
}

.use-case-box p {
    font-size: 1rem;
    color: var(--text-primary);
}

/* Pros and Cons */
.pros-cons-grid {
    display: grid;
    grid-template-columns: 1fr;
    gap: 1.5rem;
}

@media (min-width: 640px) {
    .pros-cons-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}

.pros-box, .cons-box {
    background: rgba(255, 255, 255, 0.015);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 1.25rem;
}

.pros-box h5, .cons-box h5 {
    font-size: 0.95rem;
    font-weight: 700;
    text-transform: uppercase;
    margin-bottom: 0.75rem;
}

.pros-box h5 { color: var(--behavioral); }
.cons-box h5 { color: var(--creational); }

.pros-box ul, .cons-box ul {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.pros-box li, .cons-box li {
    font-size: 0.9rem;
    color: var(--text-secondary);
    position: relative;
    padding-left: 1.25rem;
}

.pros-box li::before {
    content: '✓';
    position: absolute;
    left: 0;
    color: var(--behavioral);
    font-weight: bold;
}

.cons-box li::before {
    content: '✗';
    position: absolute;
    left: 0;
    color: var(--creational);
    font-weight: bold;
}

/* Code Column */
.modal-code-col {
    display: flex;
    flex-direction: column;
    max-height: 100%;
}

.code-header {
    background: #111827;
    border: 1px solid var(--border);
    border-bottom: none;
    border-radius: 12px 12px 0 0;
    padding: 0.75rem 1.25rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    font-size: 0.85rem;
    color: var(--text-secondary);
}

#copy-code-btn {
    background: rgba(255, 255, 255, 0.05);
    border: 1px solid var(--border);
    border-radius: 6px;
    color: var(--text-secondary);
    padding: 0.35rem 0.75rem;
    display: flex;
    align-items: center;
    gap: 0.4rem;
    cursor: pointer;
    font-size: 0.8rem;
    font-family: var(--font-sans);
    transition: var(--transition);
}

#copy-code-btn:hover {
    background: rgba(255, 255, 255, 0.1);
    color: var(--text-primary);
}

.modal-code-col pre {
    margin: 0;
    background: var(--bg-code) !important;
    border: 1px solid var(--border);
    border-radius: 0 0 12px 12px;
    padding: 1.5rem !important;
    overflow: auto;
    font-family: var(--font-mono);
    font-size: 0.9rem;
    line-height: 1.5;
    flex-grow: 1;
    max-height: 60vh;
}

.modal-code-col code {
    font-family: var(--font-mono) !important;
    background: transparent !important;
    padding: 0 !important;
    border-radius: 0 !important;
}

/* Prism overrides for seamless styling */
pre[class*="language-"] {
    background: var(--bg-code);
}