/* ==========================================================================
   LedgerLLM — Marketing Site
   Matches the dashboard design system: light-first ledger look, auto dark.
   ========================================================================== */

/* ---- Design tokens (shared with dashboard) ---- */
:root {
    --bg:        #f2f4f0;
    --surface:   #ffffff;
    --ink:       #14201b;
    --ink-2:     #4a5a52;
    --ink-3:     #66766e;
    --line:      #dde3dc;
    --track:     #ebefe9;
    --accent:    #0e6b57;
    --onaccent:  #ffffff;
    --warn:      #a8570f;
    --accent-soft: color-mix(in srgb, var(--accent) 10%, var(--surface));
    --accent-tint:  color-mix(in srgb, var(--accent) 5%, var(--surface));
    --accent-glow:  color-mix(in srgb, var(--accent) 20%, transparent);
    --radius-sm: 8px;
    --radius-md: 14px;
    --radius-lg: 16px;
    --transition: 180ms ease;
    --max-w: 1080px;
    --font-sans: "Hanken Grotesk", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
    --font-mono: "JetBrains Mono", "SF Mono", Consolas, monospace;
}

@media (prefers-color-scheme: dark) {
    :root {
        --bg:       #0f1613;
        --surface:  #172019;
        --ink:      #e8efea;
        --ink-2:    #a9b8af;
        --ink-3:    #8a9a91;
        --line:     #26332b;
        --track:    #213027;
        --accent:   #4fc3a1;
        --onaccent: #0f1613;
        --warn:     #e3944d;
        --accent-soft: color-mix(in srgb, var(--accent) 14%, var(--surface));
        --accent-tint:  color-mix(in srgb, var(--accent) 8%, var(--surface));
        --accent-glow:  color-mix(in srgb, var(--accent) 25%, transparent);
    }
}

/* ---- Reset ---- */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
ul { list-style: none; }
a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }
button { font-family: inherit; cursor: pointer; }

body {
    font-family: var(--font-sans);
    font-size: 16px;
    line-height: 1.6;
    color: var(--ink);
    background: var(--bg);
    -webkit-font-smoothing: antialiased;
}

code { font-family: var(--font-mono); font-size: 0.88em; }
.muted { color: var(--ink-3); }

/* ---- Nav ---- */
.topnav {
    position: sticky;
    top: 0;
    z-index: 100;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 32px;
    height: 60px;
    background: color-mix(in srgb, var(--surface) 88%, transparent);
    backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--line);
}
.nav-brand {
    display: flex;
    align-items: center;
    gap: 10px;
    font-weight: 700;
    font-size: 18px;
    color: var(--ink);
}
.brand-mark { border-radius: 8px; flex-shrink: 0; }
.nav-links {
    display: flex;
    align-items: center;
    gap: 4px;
}
.nav-link {
    padding: 6px 14px;
    border-radius: var(--radius-sm);
    font-size: 14px;
    font-weight: 500;
    color: var(--ink-2);
    transition: var(--transition);
}
.nav-link:hover { background: var(--accent-tint); text-decoration: none; color: var(--ink); }
.nav-link.active { background: var(--accent-soft); color: var(--accent); font-weight: 600; }
.nav-gh { display: flex; align-items: center; gap: 6px; }
.nav-toggle { display: none; background: none; border: none; color: var(--ink); padding: 8px; }

/* ---- Tabs ---- */
.tab-panel { display: none; }
.tab-panel.active { display: block; }

/* ---- Layout ---- */
.section {
    max-width: var(--max-w);
    margin: 0 auto;
    padding: 48px 32px;
}
.section-title {
    font-size: 28px;
    font-weight: 700;
    letter-spacing: -0.02em;
    margin-bottom: 8px;
}
.section-sub {
    color: var(--ink-3);
    font-size: 16px;
    margin-bottom: 32px;
}
.subsection-title {
    font-size: 20px;
    font-weight: 600;
    margin: 40px 0 16px;
    padding-top: 24px;
    border-top: 1px solid var(--line);
}

/* ---- Hero ---- */
.hero {
    max-width: var(--max-w);
    margin: 0 auto;
    padding: 64px 32px 32px;
    display: grid;
    grid-template-columns: 1.4fr 1fr;
    gap: 48px;
    align-items: center;
}
.badge {
    display: inline-block;
    padding: 4px 12px;
    border-radius: 100px;
    background: var(--accent-soft);
    color: var(--accent);
    font-size: 13px;
    font-weight: 600;
    margin-bottom: 16px;
}
.badge-cloud {
    background: color-mix(in srgb, var(--warn) 14%, var(--surface));
    color: var(--warn);
}
.hero-title {
    font-size: 44px;
    font-weight: 800;
    line-height: 1.1;
    letter-spacing: -0.03em;
    margin-bottom: 16px;
}
.accent { color: var(--accent); }
.hero-sub {
    font-size: 17px;
    color: var(--ink-2);
    line-height: 1.6;
    margin-bottom: 24px;
}
.hero-actions { display: flex; gap: 12px; flex-wrap: wrap; }
.btn {
    display: inline-flex;
    align-items: center;
    padding: 10px 20px;
    border-radius: var(--radius-sm);
    font-size: 15px;
    font-weight: 600;
    transition: var(--transition);
    border: 1px solid transparent;
}
.btn-primary {
    background: var(--accent);
    color: var(--onaccent);
}
.btn-primary:hover { filter: brightness(1.1); text-decoration: none; }
.btn-ghost {
    background: transparent;
    color: var(--ink);
    border-color: var(--line);
}
.btn-ghost:hover { background: var(--surface); border-color: var(--ink-3); text-decoration: none; }

/* ---- Hero stats ---- */
.hero-stats {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 12px;
}
.stat-card {
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: var(--radius-md);
    padding: 20px;
    text-align: center;
}
.stat-value {
    display: block;
    font-size: 28px;
    font-weight: 700;
    color: var(--accent);
    font-variant-numeric: tabular-nums;
    letter-spacing: -0.02em;
}
.stat-label {
    display: block;
    font-size: 13px;
    color: var(--ink-3);
    margin-top: 4px;
}

/* ---- Cloud banner ---- */
.cloud-banner {
    max-width: var(--max-w);
    margin: 0 auto;
    padding: 0 32px 32px;
}
.banner-content {
    background: color-mix(in srgb, var(--warn) 6%, var(--surface));
    border: 1px solid color-mix(in srgb, var(--warn) 20%, var(--line));
    border-radius: var(--radius-md);
    padding: 20px 24px;
    display: flex;
    align-items: center;
    gap: 16px;
}
.banner-content p { color: var(--ink-2); font-size: 15px; }
.banner-content .badge { margin: 0; flex-shrink: 0; }

/* ---- Flow grid ---- */
.flow-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
}
.flow-step {
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: var(--radius-md);
    padding: 20px;
}
.flow-number {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 28px;
    height: 28px;
    border-radius: 50%;
    background: var(--accent);
    color: var(--onaccent);
    font-size: 14px;
    font-weight: 700;
    margin-bottom: 12px;
}
.flow-step h3 { font-size: 16px; font-weight: 600; margin-bottom: 8px; }
.flow-step p { font-size: 14px; color: var(--ink-2); line-height: 1.5; }

/* ---- Problem grid ---- */
.problem-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
}
.problem-card {
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: var(--radius-md);
    padding: 24px;
}
.problem-icon { color: var(--warn); margin-bottom: 12px; }
.warn-icon { display: inline-flex; }
.problem-card h3 { font-size: 17px; font-weight: 600; margin-bottom: 8px; }
.problem-card p { font-size: 14px; color: var(--ink-2); line-height: 1.55; }

/* ---- Savings callout ---- */
.savings-callout {
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: var(--radius-lg);
    padding: 32px;
}
.savings-title {
    font-size: 22px;
    font-weight: 700;
    margin-bottom: 24px;
    text-align: center;
}
.savings-grid {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 16px;
    margin-bottom: 16px;
}
.savings-item {
    background: var(--track);
    border-radius: var(--radius-md);
    padding: 20px;
}
.savings-total {
    grid-column: 1 / -1;
    background: var(--accent-soft);
    border: 1px solid var(--accent);
    text-align: center;
}
.savings-header {
    font-size: 14px;
    font-weight: 600;
    color: var(--ink-2);
    margin-bottom: 12px;
}
.savings-total .savings-header { color: var(--accent); font-size: 16px; }
.savings-calc { display: flex; flex-direction: column; gap: 4px; }
.savings-line { font-size: 13px; color: var(--ink-3); }
.savings-result { font-size: 15px; font-weight: 600; color: var(--accent); margin-top: 4px; }
.savings-result-big {
    font-size: 32px;
    font-weight: 800;
    color: var(--accent);
    letter-spacing: -0.02em;
    display: block;
    margin: 4px 0;
}
.savings-note { font-size: 12px; color: var(--ink-3); text-align: center; margin-top: 8px; }

/* ---- Features grid ---- */
.features-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
}
.feature-card {
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: var(--radius-md);
    padding: 24px;
    transition: var(--transition);
}
.feature-card:hover { border-color: var(--accent); box-shadow: 0 0 0 4px var(--accent-glow); }
.feature-icon {
    color: var(--accent);
    margin-bottom: 12px;
}
.feature-card h3 { font-size: 17px; font-weight: 600; margin-bottom: 8px; }
.feature-card p { font-size: 14px; color: var(--ink-2); line-height: 1.55; }

/* ---- Providers ---- */
.providers-table {
    display: flex;
    flex-direction: column;
    gap: 8px;
}
.provider-row {
    display: flex;
    align-items: baseline;
    gap: 16px;
    padding: 12px 16px;
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: var(--radius-sm);
}
.provider-name {
    font-weight: 600;
    min-width: 100px;
    color: var(--accent);
}
.provider-models { font-size: 14px; color: var(--ink-2); }

/* ---- Quick start ---- */
.qs-steps { display: flex; flex-direction: column; gap: 24px; }
.qs-step {
    display: flex;
    gap: 16px;
    align-items: flex-start;
}
.qs-num {
    display: flex;
    align-items: center;
    justify-content: center;
    width: 32px;
    height: 32px;
    border-radius: 50%;
    background: var(--accent);
    color: var(--onaccent);
    font-size: 15px;
    font-weight: 700;
    flex-shrink: 0;
}
.qs-body { flex: 1; }
.qs-body h3 { font-size: 18px; font-weight: 600; margin-bottom: 10px; }
.qs-note { color: var(--ink-3); font-size: 14px; margin-bottom: 10px; }

/* ---- Code blocks ---- */
.code-block {
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: var(--radius-sm);
    overflow: hidden;
    margin-top: 8px;
}
.code-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 8px 14px;
    background: var(--track);
    font-size: 12px;
    color: var(--ink-3);
    font-family: var(--font-mono);
    border-bottom: 1px solid var(--line);
}
.copy-btn {
    background: none;
    border: 1px solid var(--line);
    color: var(--ink-3);
    padding: 2px 10px;
    border-radius: 4px;
    font-size: 12px;
    transition: var(--transition);
}
.copy-btn:hover { color: var(--accent); border-color: var(--accent); }
.code-block pre {
    padding: 14px 16px;
    font-family: var(--font-mono);
    font-size: 13.5px;
    line-height: 1.5;
    overflow-x: auto;
    color: var(--ink);
}
.code-block code { color: inherit; }

/* ---- Callout ---- */
.callout {
    background: var(--accent-tint);
    border: 1px solid color-mix(in srgb, var(--accent) 20%, var(--line));
    border-radius: var(--radius-md);
    padding: 20px 24px;
    margin-top: 32px;
}
.callout h4 { font-size: 15px; font-weight: 600; margin-bottom: 12px; color: var(--accent); }
.callout-cloud {
    background: color-mix(in srgb, var(--warn) 5%, var(--surface));
    border-color: color-mix(in srgb, var(--warn) 20%, var(--line));
}
.callout-cloud h4 { color: var(--warn); }

/* ---- Architecture diagram ---- */
.arch-diagram {
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: var(--radius-md);
    padding: 24px;
    display: flex;
    flex-direction: column;
    gap: 16px;
}
.arch-layer {
    display: flex;
    align-items: center;
    gap: 8px;
    flex-wrap: wrap;
}
.arch-node {
    background: var(--track);
    border: 1px solid var(--line);
    border-radius: var(--radius-sm);
    padding: 10px 16px;
    text-align: center;
    min-width: 120px;
    font-size: 14px;
    font-weight: 600;
}
.arch-sub { display: block; font-size: 11px; font-weight: 400; color: var(--ink-3); margin-top: 2px; }
.arch-arrow { color: var(--accent); font-size: 20px; font-weight: 700; }
.arch-connector { width: 2px; height: 16px; background: var(--line); margin: 0 auto; }
.arch-client { border-color: color-mix(in srgb, var(--accent) 30%, var(--line)); }
.arch-proxy { border-color: var(--accent); background: var(--accent-soft); }
.arch-classifier { border-color: var(--accent); background: var(--accent-soft); }

/* ---- CLI table ---- */
.cli-table { display: flex; flex-direction: column; gap: 4px; }
.cli-row {
    display: flex;
    align-items: baseline;
    gap: 16px;
    padding: 10px 14px;
    border-radius: var(--radius-sm);
    background: var(--surface);
    border: 1px solid var(--line);
}
.cli-row code {
    font-weight: 600;
    color: var(--accent);
    min-width: 240px;
    white-space: nowrap;
}
.cli-row span { font-size: 14px; color: var(--ink-2); }

/* ---- Tools grid ---- */
.tools-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
}
.tool-group h4 { font-size: 14px; font-weight: 600; color: var(--accent); margin-bottom: 8px; }
.tool-group ul { display: flex; flex-direction: column; gap: 4px; }
.tool-group li { font-size: 13px; color: var(--ink-2); line-height: 1.5; }
.tool-group code { color: var(--accent); font-weight: 500; }

/* ---- Strategy cards ---- */
.strategy-cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; }
.strategy-card {
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: var(--radius-md);
    padding: 20px;
}
.strategy-card h4 { font-size: 16px; font-weight: 600; margin-bottom: 8px; display: flex; align-items: center; gap: 8px; }
.badge-default {
    font-size: 11px;
    padding: 2px 8px;
    border-radius: 100px;
    background: var(--track);
    color: var(--ink-3);
}
.strategy-card p { font-size: 14px; color: var(--ink-2); line-height: 1.5; margin-bottom: 12px; }
.strategy-cost { font-size: 13px; color: var(--accent); font-weight: 500; }

/* ---- Env table ---- */
.env-table { display: flex; flex-direction: column; gap: 4px; }
.env-row {
    display: flex;
    align-items: baseline;
    gap: 16px;
    padding: 10px 14px;
    border-radius: var(--radius-sm);
    background: var(--surface);
    border: 1px solid var(--line);
}
.env-row code { font-weight: 600; color: var(--accent); min-width: 200px; white-space: nowrap; }
.env-row span { font-size: 14px; color: var(--ink-2); }

/* ---- Data flow (security) ---- */
.data-flow { display: flex; flex-direction: column; gap: 16px; }
.flow-item {
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: var(--radius-md);
    padding: 20px;
}
.flow-badge {
    display: inline-block;
    padding: 3px 10px;
    border-radius: 100px;
    font-size: 12px;
    font-weight: 600;
    margin-bottom: 8px;
}
.flow-local { background: var(--accent-soft); color: var(--accent); }
.flow-external { background: color-mix(in srgb, var(--warn) 12%, var(--surface)); color: var(--warn); }
.flow-item h4 { font-size: 16px; font-weight: 600; margin-bottom: 6px; }
.flow-item p { font-size: 14px; color: var(--ink-2); line-height: 1.55; }

/* ---- Principles grid ---- */
.principles-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 16px;
}
.principle-card {
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: var(--radius-md);
    padding: 20px;
}
.principle-icon { color: var(--accent); margin-bottom: 10px; }
.principle-card h4 { font-size: 16px; font-weight: 600; margin-bottom: 8px; }
.principle-card p { font-size: 14px; color: var(--ink-2); line-height: 1.55; }

/* ---- Limitations ---- */
.limitations-list { display: flex; flex-direction: column; gap: 12px; }
.limitation {
    padding: 14px 18px;
    background: color-mix(in srgb, var(--warn) 5%, var(--surface));
    border: 1px solid color-mix(in srgb, var(--warn) 15%, var(--line));
    border-radius: var(--radius-sm);
    font-size: 14px;
    color: var(--ink-2);
    line-height: 1.55;
}
.limitation strong { color: var(--warn); }

/* ---- Roadmap ---- */
.roadmap-list {
    margin: 12px 0;
    padding-left: 20px;
    list-style: disc;
}
.roadmap-list li { font-size: 14px; color: var(--ink-2); line-height: 1.7; }
.roadmap-note { font-size: 14px; color: var(--ink-3); margin-top: 12px; font-style: italic; }

/* ---- Footer ---- */
.footer {
    border-top: 1px solid var(--line);
    padding: 32px;
    margin-top: 48px;
}
.footer-content {
    max-width: var(--max-w);
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 16px;
    text-align: center;
}
.footer-brand {
    display: flex;
    align-items: center;
    gap: 8px;
    font-weight: 700;
    font-size: 18px;
}
.footer-links { display: flex; gap: 20px; flex-wrap: wrap; }
.footer-links a { font-size: 14px; }
.footer-note { font-size: 13px; color: var(--ink-3); }

/* ---- Responsive ---- */
@media (max-width: 900px) {
    .hero { grid-template-columns: 1fr; gap: 32px; padding: 32px; }
    .flow-grid { grid-template-columns: 1fr 1fr; }
    .features-grid { grid-template-columns: 1fr 1fr; }
    .tools-grid { grid-template-columns: 1fr 1fr; }
    .strategy-cards { grid-template-columns: 1fr; }
    .principles-grid { grid-template-columns: 1fr; }
}
@media (max-width: 600px) {
    .nav-links {
        display: none;
        position: absolute;
        top: 60px;
        left: 0;
        right: 0;
        flex-direction: column;
        background: var(--surface);
        border-bottom: 1px solid var(--line);
        padding: 12px;
        gap: 4px;
    }
    .nav-links.open { display: flex; }
    .nav-toggle { display: flex; align-items: center; }
    .section, .hero { padding-left: 20px; padding-right: 20px; }
    .flow-grid, .features-grid, .tools-grid { grid-template-columns: 1fr; }
    .problem-grid { grid-template-columns: 1fr; }
    .savings-grid { grid-template-columns: 1fr; }
    .hero-title { font-size: 32px; }
    .hero-stats { grid-template-columns: 1fr 1fr; }
    .cli-row, .env-row { flex-direction: column; gap: 4px; }
    .cli-row code, .env-row code { min-width: 0; }
}