/* MENTAL MODELS - Brutalist Linear Identity Extension */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@400;600;700;800&display=swap');

:root {
    --black: #000000;
    --white: #ffffff;
    --gray-dark: #1a1a1a;
    --gray: #666666;
    --gray-light: #e5e5e5;
    --accent: #007bff;
    --accent-dark: #0056b3;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Helvetica, Arial, sans-serif;
    background-color: var(--white);
    color: var(--black);
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 24px;
}

h1, h2, h3, h4, h5, h6 {
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1px;
    line-height: 1.2;
}

h1 { font-size: 3rem; }
h2 { font-size: 2rem; }
h3 { font-size: 1.5rem; }
h4 { font-size: 1.25rem; }

a {
    color: var(--black);
    text-decoration: underline;
    text-decoration-thickness: 2px;
    text-underline-offset: 2px;
    transition: all 0.2s ease;
}

a:hover {
    text-decoration: none;
    background-color: var(--black);
    color: var(--white);
}

header {
    border-bottom: 3px solid var(--black);
}

nav {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 24px 0;
}

nav ul {
    display: flex;
    list-style: none;
    gap: 32px;
}

nav a {
    text-decoration: none;
    font-weight: 600;
    text-transform: uppercase;
    font-size: 0.9rem;
}

.logo {
    font-weight: 800;
    font-size: 1.5rem;
    text-transform: uppercase;
    letter-spacing: 2px;
}

.hero {
    text-align: center;
    padding: 120px 0;
    background: linear-gradient(135deg, var(--white) 0%, var(--gray-light) 100%);
    border-bottom: 3px solid var(--black);
}

.hero h1 {
    margin-bottom: 24px;
    font-size: 3.5rem;
}

.hero .subtitle {
    font-size: 1.25rem;
    max-width: 700px;
    margin: 0 auto 40px;
    color: var(--gray);
}

.hero p {
    font-size: 1.125rem;
    max-width: 700px;
    margin: 0 auto 40px;
}

.btn {
    display: inline-block;
    padding: 16px 40px;
    background-color: var(--black);
    color: var(--white);
    text-decoration: none;
    text-transform: uppercase;
    font-weight: 700;
    letter-spacing: 1px;
    border: 3px solid var(--black);
    cursor: pointer;
    transition: all 0.2s ease;
}

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

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

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

.btn-small {
    padding: 10px 24px;
    font-size: 0.875rem;
}

.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 32px;
}

.card {
    border: 3px solid var(--black);
    padding: 32px;
    background: var(--white);
    transition: all 0.2s ease;
}

.card:hover {
    background: var(--black);
    color: var(--white);
    transform: translateY(-4px);
    box-shadow: 8px 8px 0 var(--black);
}

.card:hover a {
    color: var(--white);
}

.card-header {
    margin-bottom: 16px;
    padding-bottom: 16px;
    border-bottom: 2px solid var(--black);
}

.card:hover .card-header {
    border-bottom-color: var(--white);
}

.card h3 {
    margin-bottom: 8px;
}

.card .category {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 2px;
    color: var(--gray);
    margin-bottom: 8px;
}

.card:hover .category {
    color: var(--gray-light);
}

.card p {
    font-size: 0.95rem;
    margin-bottom: 16px;
}

.featured-models {
    padding: 80px 0;
}

.featured-card {
    border: 3px solid var(--black);
    padding: 40px;
    background: var(--white);
    transition: all 0.2s ease;
}

.featured-card:hover {
    background: var(--black);
    color: var(--white);
    box-shadow: 12px 12px 0 var(--accent);
}

.featured-badge {
    display: inline-block;
    padding: 4px 12px;
    background: var(--accent);
    color: var(--white);
    font-size: 0.75rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 16px;
}

.featured-card:hover .featured-badge {
    background: var(--white);
    color: var(--accent);
}

.search-section {
    padding: 60px 0;
    background: var(--gray-light);
    border-top: 3px solid var(--black);
    border-bottom: 3px solid var(--black);
}

.search-container {
    max-width: 600px;
    margin: 0 auto;
}

.search-bar {
    display: flex;
    gap: 0;
    margin-bottom: 24px;
}

.search-input {
    flex: 1;
    padding: 16px 20px;
    font-size: 1rem;
    border: 3px solid var(--black);
    border-right: none;
    font-family: inherit;
    outline: none;
}

.search-input:focus {
    border-color: var(--accent);
}

.search-btn {
    padding: 16px 32px;
    background: var(--black);
    color: var(--white);
    border: 3px solid var(--black);
    font-weight: 700;
    text-transform: uppercase;
    cursor: pointer;
    transition: all 0.2s ease;
}

.search-btn:hover {
    background: var(--accent);
    border-color: var(--accent);
}

.categories-section {
    padding: 80px 0;
}

.category-card {
    border: 3px solid var(--black);
    padding: 32px;
    background: var(--white);
    transition: all 0.2s ease;
}

.category-card:hover {
    background: var(--black);
    color: var(--white);
    box-shadow: 8px 8px 0 var(--accent);
}

.category-card h3 {
    margin-bottom: 12px;
}

.category-count {
    display: inline-block;
    padding: 4px 12px;
    background: var(--gray-light);
    color: var(--black);
    font-size: 0.875rem;
    font-weight: 700;
    margin-bottom: 16px;
}

.category-card:hover .category-count {
    background: var(--white);
    color: var(--black);
}

.quick-reference-section {
    padding: 80px 0;
    background: var(--gray-dark);
    color: var(--white);
}

.quick-reference-box {
    border: 3px solid var(--white);
    padding: 40px;
    background: var(--gray-dark);
}

.quick-reference-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 24px;
    margin-top: 32px;
}

.quick-ref-item {
    padding: 20px;
    border: 2px solid var(--white);
    transition: all 0.2s ease;
}

.quick-ref-item:hover {
    background: var(--white);
    color: var(--black);
}

.quick-ref-item h4 {
    margin-bottom: 8px;
    font-size: 1.125rem;
}

.quick-ref-item p {
    font-size: 0.875rem;
    margin: 0;
    opacity: 0.9;
}

.model-detail {
    padding: 80px 0;
}

.model-header {
    border-bottom: 3px solid var(--black);
    padding-bottom: 40px;
    margin-bottom: 40px;
}

.model-meta {
    display: flex;
    gap: 16px;
    margin-bottom: 16px;
    flex-wrap: wrap;
}

.tag {
    display: inline-block;
    padding: 4px 12px;
    background: var(--gray-light);
    color: var(--black);
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 1px;
}

.model-content {
    max-width: 800px;
}

.model-content h2 {
    margin-top: 40px;
    margin-bottom: 20px;
    font-size: 1.5rem;
}

.model-content p {
    margin-bottom: 20px;
    font-size: 1.05rem;
}

.model-content ul {
    margin-bottom: 20px;
    padding-left: 24px;
}

.model-content li {
    margin-bottom: 12px;
    font-size: 1rem;
}

.model-sidebar {
    border-left: 3px solid var(--black);
    padding-left: 40px;
}

.related-models {
    border: 3px solid var(--black);
    padding: 32px;
    margin-bottom: 32px;
}

.related-models h3 {
    margin-bottom: 20px;
    font-size: 1.25rem;
}

.related-models ul {
    list-style: none;
}

.related-models li {
    margin-bottom: 12px;
    padding-bottom: 12px;
    border-bottom: 1px solid var(--gray-light);
}

.related-models li:last-child {
    border-bottom: none;
    margin-bottom: 0;
    padding-bottom: 0;
}

.breadcrumbs {
    padding: 24px 0;
    border-bottom: 1px solid var(--gray-light);
    font-size: 0.875rem;
}

.breadcrumbs a {
    color: var(--gray);
    text-decoration: none;
}

.breadcrumbs a:hover {
    background: var(--black);
    color: var(--white);
}

.breadcrumbs span {
    color: var(--gray);
    margin: 0 8px;
}

.navigation-menu {
    background: var(--black);
    color: var(--white);
    padding: 20px 0;
}

.nav-list {
    display: flex;
    list-style: none;
    gap: 32px;
    justify-content: center;
}

.nav-list a {
    color: var(--white);
    text-decoration: none;
    font-weight: 600;
    text-transform: uppercase;
    font-size: 0.875rem;
    letter-spacing: 1px;
    padding: 8px 16px;
    transition: all 0.2s ease;
}

.nav-list a:hover {
    background: var(--white);
    color: var(--black);
}

.section-header {
    margin-bottom: 60px;
}

.section-header h2 {
    margin-bottom: 16px;
}

.accent-line {
    width: 100px;
    height: 3px;
    background: var(--black);
    margin: 32px 0;
}

.center {
    margin-left: auto;
    margin-right: auto;
}

.text-center {
    text-align: center;
}

.mb-0 { margin-bottom: 0; }
.mb-16 { margin-bottom: 16px; }
.mb-24 { margin-bottom: 24px; }
.mb-32 { margin-bottom: 32px; }
.mb-40 { margin-bottom: 40px; }
.mb-48 { margin-bottom: 48px; }
.mb-60 { margin-bottom: 60px; }
.mb-80 { margin-bottom: 80px; }

footer {
    border-top: 3px solid var(--black);
    padding: 48px 0;
    margin-top: 80px;
}

.footer-grid {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: 32px;
}

footer ul {
    list-style: none;
}

footer ul li {
    margin-bottom: 8px;
}

footer a {
    color: var(--black);
    text-decoration: underline;
}

footer a:hover {
    background: var(--black);
    color: var(--white);
}

@media (max-width: 1200px) {
    .container {
        max-width: 960px;
    }
}

@media (max-width: 992px) {
    .model-sidebar {
        border-left: none;
        padding-left: 0;
        margin-top: 60px;
        border-top: 3px solid var(--black);
        padding-top: 40px;
    }
    
    .footer-grid {
        grid-template-columns: 1fr 1fr;
    }
}

@media (max-width: 768px) {
    h1 { font-size: 2rem; }
    h2 { font-size: 1.5rem; }
    h3 { font-size: 1.25rem; }
    
    .hero {
        padding: 80px 0;
    }
    
    .hero h1 {
        font-size: 2.5rem;
    }
    
    .nav {
        flex-direction: column;
        gap: 16px;
    }
    
    nav ul {
        gap: 16px;
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .grid {
        grid-template-columns: 1fr;
    }
    
    .search-bar {
        flex-direction: column;
    }
    
    .search-input {
        border-right: 3px solid var(--black);
        border-bottom: none;
    }
    
    .footer-grid {
        grid-template-columns: 1fr;
    }
    
    .featured-card {
        padding: 24px;
    }
    
    .category-card {
        padding: 24px;
    }
    
    .card {
        padding: 24px;
    }
}

@media (max-width: 480px) {
    .container {
        padding: 0 16px;
    }
    
    .hero h1 {
        font-size: 2rem;
    }
    
    .btn {
        padding: 12px 24px;
        width: 100%;
        text-align: center;
    }
    
    .nav-list {
        flex-direction: column;
        gap: 16px;
    }
}