:root {
    --font-serif: 'Merriweather', Georgia, serif;
    --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
    --color-text: #1a1a1a;
    --color-muted: #666;
    --color-bg: #ffffff;
    --color-accent: #2563eb; /* Modern Blue */
    --color-dark: #0f172a; /* Slate 900 */
    --color-border: #e2e8f0;
    --container-width: 1000px;
}

body {
    margin: 0;
    padding: 0;
    font-family: var(--font-sans);
    color: var(--color-text);
    background-color: var(--color-bg);
    line-height: 1.6;
}

.container {
    max-width: var(--container-width);
    margin: 0 auto;
    padding: 0 2rem;
}

/* Header & Nav */
.site-header {
    padding: 1.5rem 0;
    border-bottom: 1px solid var(--color-border);
    background: #fff;
    position: sticky;
    top: 0;
    z-index: 100;
}

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

.site-title {
    font-weight: 800;
    font-size: 1.5rem;
    text-decoration: none;
    color: var(--color-dark);
    letter-spacing: -0.02em;
}

.site-nav a {
    margin-left: 2rem;
    text-decoration: none;
    color: var(--color-muted);
    font-size: 0.95rem;
    font-weight: 500;
    transition: color 0.2s;
}

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

/* Hero Section */
.hero {
    padding: 8rem 0;
    text-align: center;
    background: radial-gradient(circle at top right, #f8fafc, #fff);
}

.hero h1 {
    font-size: 4.5rem;
    font-weight: 800;
    color: var(--color-dark);
    margin-bottom: 1rem;
    letter-spacing: -0.04em;
}

.tagline {
    font-size: 1.5rem;
    color: var(--color-muted);
    margin-bottom: 2.5rem;
    max-width: 700px;
    margin-left: auto;
    margin-right: auto;
}

.cta-group {
    display: flex;
    justify-content: center;
    gap: 1rem;
}

/* Buttons */
.btn {
    padding: 0.8rem 2rem;
    border-radius: 6px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.2s;
    display: inline-block;
}

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

.btn-primary:hover {
    background-color: #1d4ed8;
    transform: translateY(-1px);
}

.btn-outline {
    border: 1px solid var(--color-border);
    color: var(--color-dark);
}

.btn-outline:hover {
    background-color: #f8fafc;
}

.btn-large {
    font-size: 1.25rem;
    padding: 1rem 3rem;
}

/* Mockup UI */
.mockup-container {
    background: #fff;
    border: 1px solid var(--color-border);
    border-radius: 12px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.05);
    overflow: hidden;
    margin: 3rem 0;
}

.mockup-header {
    background: #f8fafc;
    padding: 0.75rem 1rem;
    border-bottom: 1px solid var(--color-border);
    display: flex;
    align-items: center;
}

.dot {
    height: 12px;
    width: 12px;
    border-radius: 50%;
    margin-right: 6px;
    display: inline-block;
}

.red { background: #ff5f56; }
.yellow { background: #ffbd2e; }
.green { background: #27c93f; }

.mockup-title {
    margin-left: auto;
    margin-right: auto;
    font-size: 0.8rem;
    color: var(--color-muted);
    font-weight: 600;
}

.mockup-body {
    display: grid;
    grid-template-columns: 1fr 300px;
    min-height: 400px;
}

.mockup-editor {
    padding: 2rem;
    font-family: var(--font-serif);
    font-size: 1.2rem;
    border-right: 1px solid var(--color-border);
}

.highlight-error {
    background-color: #fee2e2;
    border-bottom: 2px solid #ef4444;
}

.mockup-sidebar {
    background: #fcfcfc;
    padding: 1.5rem;
}

.sidebar-item {
    padding: 1rem;
    border-radius: 8px;
    margin-bottom: 1rem;
    font-size: 0.85rem;
}

.sidebar-item h4 {
    margin: 0 0 0.5rem 0;
    font-size: 0.9rem;
}

.warning { background: #fffbeb; border: 1px solid #fef3c7; color: #92400e; }
.info { background: #f0f9ff; border: 1px solid #e0f2fe; color: #075985; }

/* Feature Grid */
.feature-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin: 4rem 0;
}

.feature-item {
    padding: 2rem;
    border: 1px solid var(--color-border);
    border-radius: 8px;
    transition: border-color 0.2s;
}

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

.feature-item h3 {
    margin-top: 0;
    color: var(--color-dark);
}

/* Graph Demo */
.graph-placeholder {
    padding: 4rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    background: #0f172a;
    color: #fff;
    min-height: 400px;
}

.node {
    padding: 1rem 2rem;
    border-radius: 20px;
    font-weight: bold;
    font-family: var(--font-sans);
}

.premise { background: #3b82f6; }
.fact { background: #10b981; }
.situation { background: #6366f1; }

.connector {
    width: 2px;
    height: 40px;
    background: rgba(255,255,255,0.2);
}

/* Sections */
h2 {
    font-size: 2.5rem;
    font-weight: 800;
    text-align: center;
    margin-bottom: 3rem;
    letter-spacing: -0.02em;
}

.demo-section, #features, .graph-demo, .final-cta {
    padding: 6rem 0;
}

.final-cta {
    text-align: center;
    background: #f8fafc;
}

.page-content h1 {
    font-size: 3.5rem;
    font-weight: 800;
    letter-spacing: -0.04em;
    margin-top: 4rem;
}

.page-content h2 {
    text-align: left;
    margin-top: 3rem;
    font-size: 2rem;
    border-bottom: 2px solid #eee;
    padding-bottom: 0.5rem;
}

/* Forensic Stylization */
blockquote {
    border-left: 4px solid var(--color-accent);
    padding: 1.5rem;
    background: #f8fafc;
    margin: 2rem 0;
    font-family: var(--font-sans);
    font-style: italic;
    border-radius: 0 8px 8px 0;
}

blockquote strong {
    display: block;
    margin-bottom: 0.5rem;
    font-style: normal;
    color: var(--color-accent);
    text-transform: uppercase;
    letter-spacing: 0.1em;
    font-size: 0.8rem;
}

code {
    background: #f1f5f9;
    padding: 0.2rem 0.4rem;
    border-radius: 4px;
    font-family: 'JetBrains Mono', monospace;
    font-size: 0.9rem;
    color: var(--color-dark);
}

.treatise-content h3 {
    margin-top: 4rem;
    font-size: 1.5rem;
    color: var(--color-dark);
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.treatise-content h4 {
    margin-top: 2rem;
    color: var(--color-accent);
}

.treatise-content p {
    margin-bottom: 1.2rem;
}

/* Footer */
.site-footer {
    padding: 4rem 0;
    border-top: 1px solid var(--color-border);
    background: #fff;
    color: var(--color-muted);
}