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

:root {
    --bg-primary: #ffffff;
    --bg-secondary: #fafafa;
    --bg-tertiary: #f5f5f5;
    --text-primary: #3a3a3a;
    --text-secondary: #6b6b6b;
    --text-heading: #1a1a1a;
    --accent: #4a6a7f;
    --accent-dim: #5a7a8f;
    --border: #e0e0e0;
    --border-light: #ececec;
    --mono-bg: #f8f8f8;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Inter', sans-serif;
    background: var(--bg-primary);
    color: var(--text-primary);
    line-height: 1.7;
    font-size: 15px;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
}

.mono {
    font-family: 'SF Mono', 'Monaco', 'Inconsolata', 'Roboto Mono', monospace;
    font-size: 0.9em;
    color: var(--accent);
}

/* Grid Background */
.grid-background {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-image: 
        linear-gradient(var(--border-light) 1px, transparent 1px),
        linear-gradient(90deg, var(--border-light) 1px, transparent 1px);
    background-size: 40px 40px;
    opacity: 0.6;
    pointer-events: none;
    z-index: 0;
}

/* Container */
.container {
    max-width: 1100px;
    margin: 0 auto;
    padding: 0 40px;
    position: relative;
    z-index: 1;
}

/* Typography */
h1, h2, h3, h4 {
    color: var(--text-heading);
    font-weight: 500;
    letter-spacing: -0.02em;
}

h1 {
    font-size: 3.2rem;
    line-height: 1.1;
    margin-bottom: 0.4em;
    font-weight: 400;
}

h2 {
    font-size: 1.8rem;
    margin-bottom: 1.2em;
    line-height: 1.2;
}

h3 {
    font-size: 1.3rem;
    margin-bottom: 0.6em;
}

h4 {
    font-size: 0.85rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--text-secondary);
    margin-bottom: 0.8em;
    font-weight: 500;
}

p {
    margin-bottom: 1em;
}

/* Navigation */
.nav {
    padding: 20px 0;
    border-bottom: 1px solid var(--border);
    background: var(--bg-secondary);
    position: sticky;
    top: 0;
    z-index: 100;
}

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

.nav-logo {
    font-size: 1.2rem;
    font-weight: 500;
    color: var(--text-heading);
    text-decoration: none;
    transition: color 0.2s ease;
}

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

.nav-links {
    display: flex;
    gap: 32px;
}

.nav-links a {
    color: var(--text-secondary);
    text-decoration: none;
    font-size: 0.9rem;
    transition: color 0.2s ease;
    position: relative;
}

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

.nav-links a:after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 1px;
    background: var(--accent);
    transition: width 0.2s ease;
}

.nav-links a:hover:after {
    width: 100%;
}

/* Hero Section */
.hero {
    padding: 100px 0 80px;
    border-bottom: 1px solid var(--border);
}

.tagline {
    font-size: 1.4rem;
    color: var(--text-heading);
    margin-bottom: 0.6em;
    font-weight: 400;
}

.subtitle {
    font-size: 1.05rem;
    color: var(--text-secondary);
    max-width: 600px;
    margin-bottom: 2em;
}

.hero-actions {
    display: flex;
    gap: 20px;
    flex-wrap: wrap;
}

.btn-inline {
    display: inline-block;
    padding: 10px 20px;
    border: 1px solid var(--border);
    color: var(--text-primary);
    text-decoration: none;
    font-size: 0.9rem;
    transition: all 0.2s ease;
}

.btn-inline:hover {
    border-color: var(--accent-dim);
    background: var(--bg-secondary);
}

/* Premise Section */
.premise {
    padding: 100px 0;
    border-bottom: 1px solid var(--border);
    background: var(--bg-secondary);
}

.premise-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 60px;
    margin-top: 40px;
}

.premise-block p {
    margin-bottom: 1.5em;
}

.technical-list {
    list-style: none;
    margin-top: 1.5em;
}

.technical-list li {
    padding: 8px 0;
    border-bottom: 1px solid var(--border-light);
    color: var(--text-primary);
}

.technical-list li:last-child {
    border-bottom: none;
}

/* Architecture Section */
.architecture {
    padding: 100px 0;
    border-bottom: 1px solid var(--border);
}

.section-intro {
    color: var(--text-secondary);
    max-width: 700px;
    margin-bottom: 60px;
}

.architecture-diagram {
    max-width: 800px;
    margin: 0 auto;
}

.arch-layer {
    display: flex;
    border: 1px solid var(--border);
    margin-bottom: 2px;
    background: var(--bg-secondary);
    transition: all 0.2s ease;
}

.arch-layer:hover {
    border-color: var(--accent-dim);
    background: var(--bg-tertiary);
}

.layer-number {
    width: 60px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--mono-bg);
    border-right: 1px solid var(--border);
    font-family: 'SF Mono', monospace;
    font-size: 0.8rem;
    color: var(--accent);
}

.layer-content {
    flex: 1;
    padding: 24px 28px;
}

.layer-content h3 {
    font-size: 1.1rem;
    margin-bottom: 0.3em;
}

.layer-content p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin: 0;
}

.arch-base {
    margin-top: 12px;
    padding: 16px 28px;
    background: var(--mono-bg);
    border: 1px solid var(--border);
    text-align: center;
    font-size: 0.85rem;
}

/* Deep-Dive Section */
.deep-dive {
    padding: 100px 0;
    border-bottom: 1px solid var(--border);
    background: var(--bg-secondary);
}

.module-card {
    margin-bottom: 60px;
    border: 1px solid var(--border);
    background: var(--bg-primary);
}

.module-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 24px 32px;
    border-bottom: 1px solid var(--border);
}

.module-header h3 {
    margin: 0;
    font-size: 1.3rem;
}

.module-tag {
    font-family: 'SF Mono', monospace;
    font-size: 0.75rem;
    color: var(--accent);
    background: var(--mono-bg);
    padding: 4px 12px;
    border: 1px solid var(--border);
}

.module-body {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 0;
}

.module-section {
    padding: 28px 32px;
    border-right: 1px solid var(--border-light);
    border-bottom: 1px solid var(--border-light);
}

.module-section:last-child {
    border-right: none;
    grid-column: 1 / -1;
}

.module-section h4 {
    margin-bottom: 1em;
}

.module-section p {
    font-size: 0.95rem;
    color: var(--text-secondary);
}

.mono-list {
    list-style: none;
}

.mono-list li {
    font-family: 'SF Mono', monospace;
    font-size: 0.85rem;
    padding: 6px 0;
    color: var(--text-primary);
    line-height: 1.6;
}

.mono-list li:before {
    content: "→";
    color: var(--accent-dim);
    margin-right: 10px;
}

/* Governance Section */
.governance {
    padding: 100px 0;
    border-bottom: 1px solid var(--border);
}

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

.formula {
    padding: 32px;
    background: var(--mono-bg);
    border: 1px solid var(--border);
    margin-bottom: 40px;
}

.formula p {
    font-size: 1.05rem;
    color: var(--accent);
    margin: 0;
}

.governance-explanation p {
    margin-bottom: 1.5em;
    color: var(--text-secondary);
}

/* Principles Section */
.principles {
    padding: 100px 0;
    border-bottom: 1px solid var(--border);
    background: var(--bg-secondary);
}

.principles-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 2px;
    margin-top: 40px;
}

.principle {
    padding: 40px 32px;
    background: var(--bg-primary);
    border: 1px solid var(--border);
    transition: all 0.2s ease;
}

.principle:hover {
    border-color: var(--accent-dim);
}

.principle p {
    font-size: 1.05rem;
    color: var(--text-heading);
    margin: 0;
}

/* Footer */
.footer {
    padding: 80px 0;
    background: var(--bg-primary);
}

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

.footer-title {
    font-size: 1.2rem;
    color: var(--text-heading);
    margin-bottom: 0.3em;
}

.footer-subtitle {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: 1.5em;
}

.footer-version {
    font-family: 'SF Mono', monospace;
    font-size: 0.8rem;
    color: var(--accent-dim);
}

/* Page Header */
.page-header {
    padding: 80px 0 60px;
    border-bottom: 1px solid var(--border);
}

.page-header h1 {
    font-size: 2.8rem;
    margin-bottom: 0.5em;
}

.page-subtitle {
    font-size: 1.1rem;
    color: var(--text-secondary);
    max-width: 700px;
}

/* Content Section */
.content-section {
    padding: 80px 0;
}

.content-section h2 {
    margin-top: 60px;
    margin-bottom: 1.5em;
    padding-top: 20px;
    border-top: 1px solid var(--border-light);
}

.content-section h2:first-child {
    margin-top: 0;
    border-top: none;
    padding-top: 0;
}

.content-section h3 {
    margin-top: 2em;
    margin-bottom: 1em;
}

/* Architecture Page */
.architecture-principles {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 24px;
    margin: 40px 0 60px;
}

.principle-card {
    padding: 28px;
    border: 1px solid var(--border);
    background: var(--bg-secondary);
}

.principle-card h3 {
    font-size: 1.1rem;
    margin-bottom: 0.8em;
    margin-top: 0;
}

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

.flow-diagram {
    max-width: 600px;
    margin: 40px auto;
}

.flow-step {
    display: flex;
    gap: 20px;
    padding: 24px;
    border: 1px solid var(--border);
    background: var(--bg-secondary);
    margin-bottom: 0;
}

.flow-number {
    width: 40px;
    height: 40px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--mono-bg);
    border: 1px solid var(--border);
    border-radius: 50%;
    font-weight: 500;
    color: var(--accent);
    flex-shrink: 0;
}

.flow-content h4 {
    margin-bottom: 0.5em;
    margin-top: 0;
    text-transform: none;
    letter-spacing: normal;
    color: var(--text-heading);
    font-size: 1rem;
}

.flow-content p {
    margin: 0;
    font-size: 0.9rem;
}

.flow-arrow {
    text-align: center;
    color: var(--accent);
    font-size: 1.5rem;
    padding: 8px 0;
}

/* Layers Page */
.layer-detail {
    margin-bottom: 80px;
    padding-bottom: 60px;
    border-bottom: 1px solid var(--border-light);
}

.layer-detail:last-child {
    border-bottom: none;
}

.layer-detail-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5em;
}

.layer-badge {
    font-size: 0.75rem;
    text-transform: uppercase;
    letter-spacing: 0.08em;
    color: var(--accent);
    background: var(--mono-bg);
    padding: 6px 14px;
    border: 1px solid var(--border);
}

.layer-description {
    font-size: 1.05rem;
    color: var(--text-secondary);
    margin-bottom: 2em;
    line-height: 1.7;
}

.component-list {
    list-style: none;
    margin: 1.5em 0;
}

.component-list li {
    padding: 12px 0;
    border-bottom: 1px solid var(--border-light);
}

.component-list li:last-child {
    border-bottom: none;
}

.component-list strong {
    color: var(--text-heading);
    font-weight: 500;
}

.api-block {
    display: flex;
    align-items: center;
    gap: 16px;
    padding: 16px 20px;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    margin-bottom: 8px;
}

.api-method {
    font-family: 'SF Mono', monospace;
    font-size: 0.75rem;
    font-weight: 600;
    color: var(--accent);
    background: var(--mono-bg);
    padding: 4px 10px;
    border: 1px solid var(--border);
}

.api-path {
    font-family: 'SF Mono', monospace;
    font-size: 0.9rem;
    color: var(--text-heading);
}

.api-desc {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* Governance Page */
.formula-section {
    margin: 40px 0 60px;
}

.weight-components {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
    margin: 40px 0 60px;
}

.weight-card {
    padding: 32px;
    border: 1px solid var(--border);
    background: var(--bg-secondary);
}

.weight-card h3 {
    margin-top: 0;
    margin-bottom: 0.8em;
    font-size: 1.2rem;
}

.weight-metric {
    font-size: 2.5rem;
    font-weight: 500;
    color: var(--accent);
    margin-bottom: 1em;
}

.metric-list {
    list-style: none;
    margin-top: 1em;
}

.metric-list li {
    padding: 6px 0;
    font-size: 0.9rem;
    color: var(--text-secondary);
}

.metric-list li:before {
    content: "→";
    color: var(--accent-dim);
    margin-right: 8px;
}

.calibration-table {
    margin: 40px 0;
    border: 1px solid var(--border);
}

.table-header,
.table-row {
    display: grid;
    grid-template-columns: 2fr 1fr 1fr 1fr;
    border-bottom: 1px solid var(--border);
}

.table-header {
    background: var(--mono-bg);
}

.table-header .table-cell {
    font-weight: 500;
    color: var(--text-heading);
    text-transform: uppercase;
    font-size: 0.75rem;
    letter-spacing: 0.05em;
}

.table-row:last-child {
    border-bottom: none;
}

.table-row:hover {
    background: var(--bg-tertiary);
}

.table-cell {
    padding: 16px 20px;
    border-right: 1px solid var(--border-light);
    font-size: 0.9rem;
}

.table-cell:last-child {
    border-right: none;
}

.decay-formula {
    background: var(--mono-bg);
    border: 1px solid var(--border);
    padding: 24px 28px;
    margin: 30px 0;
}

.decay-formula .mono {
    font-size: 1.1rem;
    display: block;
    margin-bottom: 12px;
}

.decay-note {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin: 0;
}

.decay-parameters {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 2px;
    margin: 30px 0;
}

.param-item {
    background: var(--bg-secondary);
    border: 1px solid var(--border);
    padding: 20px 24px;
    text-align: center;
}

.param-label {
    font-size: 0.85rem;
    color: var(--text-secondary);
    margin-bottom: 8px;
}

.param-value {
    font-size: 1.3rem;
    color: var(--text-heading);
    font-weight: 500;
}

.process-list {
    list-style: none;
    counter-reset: process-counter;
    margin: 30px 0;
}

.process-list li {
    counter-increment: process-counter;
    padding: 16px 0 16px 60px;
    position: relative;
    border-bottom: 1px solid var(--border-light);
}

.process-list li:last-child {
    border-bottom: none;
}

.process-list li:before {
    content: counter(process-counter);
    position: absolute;
    left: 0;
    top: 16px;
    width: 36px;
    height: 36px;
    display: flex;
    align-items: center;
    justify-content: center;
    background: var(--mono-bg);
    border: 1px solid var(--border);
    border-radius: 50%;
    color: var(--accent);
    font-weight: 500;
}

/* Documentation Page */
.quickstart-section {
    margin: 40px 0 60px;
}

.code-block {
    background: var(--mono-bg);
    border: 1px solid var(--border);
    padding: 24px;
    overflow-x: auto;
    margin: 20px 0;
}

.code-block pre {
    margin: 0;
    font-family: 'SF Mono', monospace;
    font-size: 0.85rem;
    line-height: 1.6;
    color: var(--text-primary);
}

.code-block code {
    font-family: 'SF Mono', monospace;
}

.pattern-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
    gap: 24px;
    margin: 40px 0 60px;
}

.pattern-card {
    padding: 28px;
    border: 1px solid var(--border);
    background: var(--bg-secondary);
}

.pattern-card h3 {
    margin-top: 0;
    margin-bottom: 0.8em;
}

.pattern-card p {
    font-size: 0.9rem;
    color: var(--text-secondary);
    margin-bottom: 1.5em;
}

.pattern-code {
    font-family: 'SF Mono', monospace;
    font-size: 0.85rem;
    background: var(--mono-bg);
    padding: 8px 12px;
    border: 1px solid var(--border);
    color: var(--accent);
}

.api-reference {
    margin: 40px 0;
}

.api-reference h3 {
    margin-top: 60px;
    padding-top: 40px;
    border-top: 1px solid var(--border-light);
}

.api-reference h3:first-child {
    margin-top: 0;
    padding-top: 0;
    border-top: none;
}

.api-section {
    margin: 30px 0;
}

.api-endpoint {
    margin: 30px 0;
    padding: 28px;
    border: 1px solid var(--border);
    background: var(--bg-secondary);
}

.api-endpoint-header {
    display: flex;
    align-items: center;
    gap: 16px;
    margin-bottom: 1em;
}

.api-method-badge {
    font-family: 'SF Mono', monospace;
    font-size: 0.7rem;
    font-weight: 600;
    color: var(--accent);
    background: var(--mono-bg);
    padding: 6px 12px;
    border: 1px solid var(--border);
}

.api-endpoint-header code {
    font-family: 'SF Mono', monospace;
    font-size: 0.95rem;
    color: var(--text-heading);
}

.api-params,
.api-response {
    margin-top: 24px;
}

.api-params h4,
.api-response h4 {
    margin-bottom: 1em;
}

.param-list {
    list-style: none;
    margin: 16px 0;
}

.param-list li {
    padding: 8px 0;
    font-size: 0.9rem;
}

.param-list code {
    font-family: 'SF Mono', monospace;
    color: var(--accent);
    font-size: 0.85rem;
}

.example-section {
    margin: 40px 0 60px;
}

.status-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 2px;
    margin: 30px 0;
}

.status-item {
    padding: 24px;
    background: var(--bg-secondary);
    border: 1px solid var(--border);
}

.status-label {
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-secondary);
    margin-bottom: 8px;
}

.status-value {
    font-size: 1.1rem;
    color: var(--text-heading);
}

.status-value.mono {
    font-family: 'SF Mono', monospace;
    font-size: 0.9rem;
}

.status-active {
    color: var(--accent);
    font-weight: 500;
}

/* Responsive */
@media (max-width: 768px) {
    .container {
        padding: 0 24px;
    }

    h1 {
        font-size: 2.4rem;
    }

    h2 {
        font-size: 1.5rem;
    }

    .nav-links {
        gap: 16px;
        font-size: 0.85rem;
    }

    .hero {
        padding: 80px 0 60px;
    }

    .page-header {
        padding: 60px 0 40px;
    }

    .page-header h1 {
        font-size: 2.2rem;
    }

    .content-section {
        padding: 60px 0;
    }

    .premise-grid {
        grid-template-columns: 1fr;
        gap: 40px;
    }

    .premise,
    .architecture,
    .deep-dive,
    .governance,
    .principles {
        padding: 60px 0;
    }

    .module-body {
        grid-template-columns: 1fr;
    }

    .module-section {
        border-right: none;
    }

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

    .architecture-principles,
    .weight-components,
    .pattern-grid {
        grid-template-columns: 1fr;
    }

    .table-header,
    .table-row {
        grid-template-columns: 1.5fr 1fr 1fr 1fr;
        font-size: 0.8rem;
    }

    .table-cell {
        padding: 12px 10px;
    }

    .api-endpoint-header {
        flex-direction: column;
        align-items: flex-start;
    }

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

/* Smooth scroll */
html {
    scroll-behavior: smooth;
}

/* Selection */
::selection {
    background: var(--accent-dim);
    color: var(--text-heading);
}