/* unpriced — stylesheet */

:root {
  color-scheme: light dark;
  --color-teal: #0d9488;
  --color-teal-light: rgba(13,148,136,0.12);
  --color-teal-hover: #0f766e;
  --color-amber: #d97706;
  --color-amber-light: rgba(217,119,6,0.10);
  --color-slate: #475569;
  --color-slate-blue: #3b82f6;
  --color-red: #dc2626;
  --color-red-light: rgba(220,38,38,0.08);
  --color-green: #16a34a;
  --color-green-light: rgba(22,163,74,0.10);
  --color-text: #1e293b;
  --color-text-secondary: #64748b;
  --color-text-muted: #94a3b8;
  --color-heading: #0f172a;
  --color-bg: #ffffff;
  --color-bg-alt: #f8fafc;
  --color-bg-card: #ffffff;
  --color-border: #e2e8f0;
  --color-border-light: #f1f5f9;
  --color-hero-bg: linear-gradient(135deg, #0f172a 0%, #134e4a 100%);
  --color-header-bg: #0f172a;
  --color-insight-bg: linear-gradient(135deg, #f0fdfa 0%, #ecfdf5 100%);
  --color-insight-border: #0d9488;
  --color-insight-text: #134e4a;
  --color-warning-bg: #fef2f2;
  --color-warning-border: #dc2626;
  --color-warning-text: #991b1b;
  --color-chart-grid: rgba(0,0,0,0.06);
  --color-chart-text: #64748b;
  --color-muted: #cbd5e1;
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  --font-mono: 'SF Mono', 'Fira Code', 'Fira Mono', 'Roboto Mono', Menlo, monospace;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.04);
  --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.06), 0 2px 4px -2px rgba(0,0,0,0.04);
  --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.07), 0 4px 6px -4px rgba(0,0,0,0.03);
  --radius: 8px;
  --radius-lg: 12px;
  --max-width: 1100px;
  --transition: 0.2s ease;
}

[data-theme="dark"] {
  --color-teal: #2dd4bf;
  --color-teal-light: rgba(45,212,191,0.15);
  --color-teal-hover: #5eead4;
  --color-amber: #fbbf24;
  --color-amber-light: rgba(251,191,36,0.15);
  --color-slate: #94a3b8;
  --color-slate-blue: #7dd3fc;
  --color-red: #f87171;
  --color-red-light: rgba(248,113,113,0.12);
  --color-green: #4ade80;
  --color-green-light: rgba(74,222,128,0.12);
  --color-text: #e2e8f0;
  --color-text-secondary: #94a3b8;
  --color-text-muted: #64748b;
  --color-heading: #f1f5f9;
  --color-bg: #0f172a;
  --color-bg-alt: #1e293b;
  --color-bg-card: #1e293b;
  --color-border: #334155;
  --color-border-light: #1e293b;
  --color-hero-bg: linear-gradient(135deg, #020617 0%, #042f2e 100%);
  --color-header-bg: #020617;
  --color-insight-bg: linear-gradient(135deg, #042f2e 0%, #064e3b 100%);
  --color-insight-border: #2dd4bf;
  --color-insight-text: #ccfbf1;
  --color-warning-bg: #1c1917;
  --color-warning-border: #f87171;
  --color-warning-text: #fecaca;
  --color-chart-grid: rgba(255,255,255,0.06);
  --color-chart-text: #94a3b8;
  --color-muted: #334155;
  --shadow-sm: 0 1px 2px rgba(0,0,0,0.3);
  --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.4), 0 2px 4px -2px rgba(0,0,0,0.3);
  --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.5), 0 4px 6px -4px rgba(0,0,0,0.3);
}

@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --color-teal: #2dd4bf;
    --color-teal-light: rgba(45,212,191,0.15);
    --color-teal-hover: #5eead4;
    --color-amber: #fbbf24;
    --color-amber-light: rgba(251,191,36,0.15);
    --color-slate: #94a3b8;
    --color-slate-blue: #7dd3fc;
    --color-red: #f87171;
    --color-red-light: rgba(248,113,113,0.12);
    --color-green: #4ade80;
    --color-green-light: rgba(74,222,128,0.12);
    --color-text: #e2e8f0;
    --color-text-secondary: #94a3b8;
    --color-text-muted: #64748b;
    --color-heading: #f1f5f9;
    --color-bg: #0f172a;
    --color-bg-alt: #1e293b;
    --color-bg-card: #1e293b;
    --color-border: #334155;
    --color-border-light: #1e293b;
    --color-hero-bg: linear-gradient(135deg, #020617 0%, #042f2e 100%);
    --color-header-bg: #020617;
    --color-insight-bg: linear-gradient(135deg, #042f2e 0%, #064e3b 100%);
    --color-insight-border: #2dd4bf;
    --color-insight-text: #ccfbf1;
    --color-warning-bg: #1c1917;
    --color-warning-border: #f87171;
    --color-warning-text: #fecaca;
    --color-chart-grid: rgba(255,255,255,0.06);
    --color-chart-text: #94a3b8;
    --color-muted: #334155;
    --shadow-sm: 0 1px 2px rgba(0,0,0,0.3);
    --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.4), 0 2px 4px -2px rgba(0,0,0,0.3);
    --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.5), 0 4px 6px -4px rgba(0,0,0,0.3);
  }
}

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }
html { scroll-behavior: smooth; -webkit-font-smoothing: antialiased; scroll-padding-top: 70px; }

body {
  font-family: var(--font-sans);
  font-size: 16px;
  line-height: 1.7;
  color: var(--color-text);
  background: var(--color-bg);
  transition: background 0.3s ease, color 0.3s ease;
}

/* ── Typography ── */
h1, h2, h3, h4 { line-height: 1.3; font-weight: 700; color: var(--color-heading); }
h1 { font-size: 2.5rem; letter-spacing: -0.03em; }
h2 { font-size: 1.75rem; letter-spacing: -0.01em; margin-top: 0; margin-bottom: 1rem; }
h3 { font-size: 1.25rem; margin-top: 0; margin-bottom: 0.75rem; }
p { margin-bottom: 1rem; }
a { color: var(--color-teal); text-decoration: none; transition: color var(--transition); }
a:hover { color: var(--color-teal-hover); text-decoration: underline; }
strong { font-weight: 600; }
code { font-family: var(--font-mono); font-size: 0.875em; background: var(--color-bg-alt); padding: 0.15em 0.4em; border-radius: 4px; color: var(--color-text); }

/* ── Header / Nav ── */
.site-header { background: var(--color-header-bg); color: #fff; position: sticky; top: 0; z-index: 100; box-shadow: var(--shadow-md); }
.header-inner { max-width: var(--max-width); margin: 0 auto; padding: 0 1.5rem; display: flex; align-items: center; justify-content: space-between; height: 60px; }
.site-logo { font-size: 1.25rem; font-weight: 700; color: #fff; text-decoration: none; letter-spacing: -0.02em; flex-shrink: 0; }
.site-logo:hover { color: var(--color-teal); text-decoration: none; }
.site-logo .logo-accent { color: var(--color-teal); }
.header-controls { display: flex; align-items: center; gap: 0.5rem; }
.nav-links { display: flex; gap: 0; list-style: none; overflow-x: auto; scrollbar-width: none; -ms-overflow-style: none; }
.nav-links::-webkit-scrollbar { display: none; }
.nav-links a { color: rgba(255,255,255,0.7); padding: 0.4rem 0.65rem; border-radius: 6px; font-size: 0.8rem; font-weight: 500; transition: all var(--transition); white-space: nowrap; }
.nav-links a:hover, .nav-links a.active { color: #fff; background: rgba(255,255,255,0.1); text-decoration: none; }
.theme-toggle { background: none; border: 1px solid rgba(255,255,255,0.2); color: rgba(255,255,255,0.8); width: 36px; height: 36px; border-radius: 8px; cursor: pointer; display: flex; align-items: center; justify-content: center; font-size: 1.1rem; transition: all var(--transition); flex-shrink: 0; }
.theme-toggle:hover { background: rgba(255,255,255,0.1); color: #fff; border-color: rgba(255,255,255,0.3); }
.nav-toggle { display: none; background: none; border: none; color: #fff; font-size: 1.5rem; cursor: pointer; padding: 0.25rem; }

/* ── Hero ── */
.hero { background: var(--color-hero-bg); color: #fff; padding: 4.5rem 1.5rem 3.5rem; }
.hero-inner { max-width: var(--max-width); margin: 0 auto; }
.hero h1 { color: #fff; font-size: 3rem; margin-bottom: 0.25rem; letter-spacing: -0.04em; }
.hero .hero-subtitle { font-size: 1.15rem; color: rgba(255,255,255,0.7); margin-bottom: 0.5rem; font-weight: 400; }
.hero .hero-desc { font-size: 1rem; color: rgba(255,255,255,0.65); max-width: 680px; line-height: 1.6; }

/* ── Stats Row (Hero) ── */
.stats-row { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1rem; margin: 2rem 0 0; max-width: 600px; }
.stat-chip { background: rgba(255,255,255,0.06); border: 1px solid rgba(255,255,255,0.1); border-radius: var(--radius); padding: 1rem 1.25rem; text-align: center; transition: transform 0.2s ease, background 0.2s ease; }
.stat-chip:hover { background: rgba(255,255,255,0.1); transform: translateY(-2px); }
.stat-chip .stat-value { font-size: 1.6rem; font-weight: 800; color: #fff; font-family: var(--font-mono); letter-spacing: -0.02em; }
.stat-chip .stat-label { font-size: 0.7rem; text-transform: uppercase; letter-spacing: 0.08em; color: rgba(255,255,255,0.5); margin-top: 0.1rem; }

/* ── Content ── */
.content { max-width: var(--max-width); margin: 0 auto; padding: 2.5rem 1.5rem 4rem; }

/* ── Read Guide ── */
.read-guide { margin: 0 0 2.25rem; }
.read-guide h2 { margin-bottom: 0.85rem; font-size: 1.35rem; }
.read-guide-grid { display: grid; grid-template-columns: repeat(2, minmax(0, 1fr)); gap: 0.75rem; }
.read-guide-item { border: 1px solid var(--color-border); background: var(--color-bg-alt); border-radius: var(--radius); padding: 0.8rem 0.95rem; }
.read-guide-item h3 { font-size: 0.86rem; letter-spacing: 0.04em; text-transform: uppercase; color: var(--color-teal); margin-bottom: 0.35rem; }
.read-guide-item p { margin: 0; font-size: 0.87rem; color: var(--color-text-secondary); line-height: 1.45; }

/* ── Section ── */
.section { margin-bottom: 3.5rem; }
.section-header { display: flex; align-items: baseline; gap: 1rem; margin-bottom: 1.25rem; border-bottom: 2px solid var(--color-teal); padding-bottom: 0.5rem; }
.section-header h2 { margin: 0; }
.section-header .section-tag { font-size: 0.7rem; text-transform: uppercase; letter-spacing: 0.08em; color: var(--color-teal); font-weight: 600; }
.section-takeaway { font-size: 0.92rem; color: var(--color-text-secondary); margin: 0.25rem 0 1rem; }

/* ── Cards ── */
.card { background: var(--color-bg-card); border: 1px solid var(--color-border); border-radius: var(--radius-lg); padding: 1.75rem; box-shadow: var(--shadow-sm); transition: box-shadow var(--transition), transform var(--transition); }
.card:hover { box-shadow: var(--shadow-md); transform: translateY(-1px); }
.card h3 { margin-top: 0; }

/* ── Chart Container ── */
.chart-container { background: var(--color-bg-card); border: 1px solid var(--color-border); border-radius: var(--radius-lg); padding: 1.5rem; margin: 1.5rem 0; box-shadow: var(--shadow-sm); }
.chart-container h3 { margin-top: 0; margin-bottom: 0.25rem; font-size: 1.1rem; }
.chart-container .chart-subtitle { font-size: 0.85rem; color: var(--color-text-secondary); margin-bottom: 1rem; }
.chart-canvas-wrap { position: relative; width: 100%; }
.chart-canvas-wrap canvas { width: 100% !important; }
.chart-canvas-wrap.tall { min-height: 450px; }
.chart-note { font-size: 0.8rem; color: var(--color-text-muted); margin-top: 0.75rem; font-style: italic; }
.chart-legend { display: flex; gap: 1.25rem; flex-wrap: wrap; margin-top: 0.75rem; }
.chart-legend-item { display: flex; align-items: center; gap: 0.4rem; font-size: 0.85rem; color: var(--color-text-secondary); }
.chart-legend-swatch { width: 14px; height: 14px; border-radius: 3px; flex-shrink: 0; }

/* ── Tables ── */
.table-wrap { overflow-x: auto; -webkit-overflow-scrolling: touch; margin: 1rem 0; }
.data-table { width: 100%; border-collapse: collapse; font-size: 0.9rem; }
.data-table th { text-align: left; font-weight: 600; color: var(--color-heading); border-bottom: 2px solid var(--color-teal); padding: 0.75rem 1rem; white-space: nowrap; }
.data-table td { padding: 0.6rem 1rem; border-bottom: 1px solid var(--color-border-light); color: var(--color-text); }
.data-table tr:hover td { background: var(--color-bg-alt); }
.data-table .num { text-align: right; font-family: var(--font-mono); font-size: 0.85rem; }
.data-table .highlight { font-weight: 600; color: var(--color-heading); }

/* ── Badges ── */
.badge { display: inline-block; padding: 0.2em 0.6em; border-radius: 4px; font-size: 0.72rem; font-weight: 600; text-transform: uppercase; letter-spacing: 0.04em; white-space: nowrap; }
.badge-teal { background: var(--color-teal-light); color: var(--color-teal); }
.badge-amber { background: var(--color-amber-light); color: var(--color-amber); }
.badge-red { background: var(--color-red-light); color: var(--color-red); }
.badge-green { background: var(--color-green-light); color: var(--color-green); }

/* ── Insight / Warning ── */
.insight-box { background: var(--color-insight-bg); border-left: 4px solid var(--color-insight-border); border-radius: 0 var(--radius) var(--radius) 0; padding: 1.25rem 1.5rem; margin: 1.5rem 0; }
.insight-box p { margin-bottom: 0; color: var(--color-insight-text); font-size: 0.92rem; }
.insight-box strong { color: var(--color-heading); }
.warning-box { background: var(--color-warning-bg); border-left: 4px solid var(--color-warning-border); border-radius: 0 var(--radius) var(--radius) 0; padding: 1.25rem 1.5rem; margin: 1.5rem 0; }
.warning-box p { margin-bottom: 0; color: var(--color-warning-text); font-size: 0.92rem; }
.status-line-box { background: var(--color-bg-alt); border-left: 4px solid var(--color-teal); border-radius: 0 var(--radius) var(--radius) 0; padding: 0.85rem 1rem; margin: 1rem 0 0; }
.status-line-box p { margin: 0; color: var(--color-text-secondary); font-size: 0.9rem; }
.status-line-box strong { color: var(--color-heading); }
.table-note { font-size: 0.82rem; color: var(--color-text-muted); margin: 0.25rem 0 0.25rem; }

/* ── Method Support Blocks ── */
.optional-method-intro { font-size: 0.9rem; color: var(--color-text-secondary); margin-bottom: 1rem; }
.dual-shift-callout { margin: 1rem 0 1.25rem; border: 1px solid var(--color-border); border-radius: var(--radius); background: var(--color-bg-alt); padding: 0.95rem 1rem 0.35rem; }
.dual-shift-callout h4 { margin: 0 0 0.45rem; font-size: 0.92rem; color: var(--color-heading); }
.dual-shift-mini-table { font-size: 0.84rem; }

/* ── Collapsible ── */
.collapsible { margin: 1rem 0; }
.collapsible-header { display: flex; align-items: center; justify-content: space-between; cursor: pointer; padding: 0.85rem 1.25rem; background: var(--color-bg-alt); border: 1px solid var(--color-border); border-radius: var(--radius); transition: all var(--transition); user-select: none; }
.collapsible-header:hover { background: var(--color-border-light); }
.collapsible-header h4 { margin: 0; font-size: 0.95rem; color: var(--color-heading); }
.collapsible-arrow { font-size: 0.8rem; color: var(--color-text-secondary); transition: transform 0.2s ease; }
.collapsible-body { max-height: 0; overflow: hidden; transition: max-height 0.35s ease; }
.collapsible.open .collapsible-body { max-height: 3000px; }
.collapsible.open .collapsible-arrow { transform: rotate(90deg); }
.collapsible-inner { padding: 1rem 1.25rem 0.5rem; }

/* ── Sample ladder cards ── */
.ladder-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 1rem; margin: 1.5rem 0; }
.ladder-card { background: var(--color-bg-card); border: 1px solid var(--color-border); border-radius: var(--radius); padding: 1.25rem; text-align: center; position: relative; }
.ladder-card.headline { border-color: var(--color-teal); border-width: 2px; }
.ladder-card .lc-name { font-size: 0.85rem; font-weight: 700; color: var(--color-heading); text-transform: uppercase; letter-spacing: 0.04em; }
.ladder-card .lc-rows { font-size: 1.75rem; font-weight: 800; font-family: var(--font-mono); color: var(--color-teal); margin: 0.25rem 0; }
.ladder-card .lc-detail { font-size: 0.78rem; color: var(--color-text-secondary); }
.ladder-card .lc-badges { display: flex; gap: 0.5rem; justify-content: center; margin-top: 0.6rem; flex-wrap: wrap; }

/* ── Timeline bar ── */
.timeline-bar { background: var(--color-bg-alt); border: 1px solid var(--color-border); border-radius: var(--radius); padding: 1.25rem; margin: 1.5rem 0; position: relative; }
.timeline-track { height: 32px; background: var(--color-muted); border-radius: 4px; position: relative; overflow: hidden; margin: 0.75rem 0; }
.timeline-fill { position: absolute; top: 0; height: 100%; background: var(--color-teal); border-radius: 4px; display: flex; align-items: center; justify-content: center; font-size: 0.75rem; font-weight: 600; color: #fff; }
.timeline-labels { display: flex; justify-content: space-between; font-size: 0.78rem; color: var(--color-text-secondary); font-family: var(--font-mono); }

/* ── Limitation cards ── */
.limitation-list { display: grid; gap: 0.75rem; margin: 1rem 0; }
.limitation-item { background: var(--color-bg-alt); border: 1px solid var(--color-border); border-radius: var(--radius); padding: 1rem 1.25rem; }
.limitation-item strong { color: var(--color-heading); font-size: 0.9rem; }
.limitation-item p { margin: 0.25rem 0 0; font-size: 0.88rem; color: var(--color-text-secondary); }

/* ── Footer ── */
.site-footer { background: var(--color-header-bg); color: rgba(255,255,255,0.5); padding: 2rem 1.5rem; font-size: 0.85rem; margin-top: 4rem; }
.footer-inner { max-width: var(--max-width); margin: 0 auto; display: flex; justify-content: space-between; align-items: center; flex-wrap: wrap; gap: 1rem; }
.footer-inner a { color: rgba(255,255,255,0.7); }
.footer-inner a:hover { color: #fff; }

/* ── Responsive ── */
@media (max-width: 768px) {
  h1 { font-size: 1.75rem; }
  h2 { font-size: 1.4rem; }
  .hero { padding: 2.5rem 1rem 2rem; }
  .hero h1 { font-size: 2.25rem; }
  .header-inner { height: 56px; }
  .nav-toggle { display: block; }
  .nav-links { display: none; position: absolute; top: 56px; left: 0; right: 0; background: var(--color-header-bg); flex-direction: column; padding: 0.5rem; border-top: 1px solid rgba(255,255,255,0.1); box-shadow: var(--shadow-lg); z-index: 50; }
  .nav-links.open { display: flex; }
  .nav-links a { padding: 0.75rem 1rem; }
  .stats-row { grid-template-columns: 1fr; max-width: 100%; }
  .chart-container { padding: 1rem; }
  .content { padding: 1.5rem 1rem 3rem; }
  .read-guide-grid { grid-template-columns: 1fr; gap: 0.6rem; }
  .data-table { font-size: 0.8rem; }
  .data-table th, .data-table td { padding: 0.5rem 0.5rem; }
  .ladder-grid { grid-template-columns: 1fr; }
  .footer-inner { flex-direction: column; text-align: center; }
}
@media (max-width: 480px) {
  .stats-row { grid-template-columns: 1fr; }
  .stat-chip .stat-value { font-size: 1.35rem; }
}

@media print {
  .site-header, .site-footer, .nav-toggle, .theme-toggle { display: none; }
  .hero { background: #f0fdfa; color: #0f172a; padding: 1.5rem; }
  .hero h1, .hero .hero-subtitle, .hero .hero-desc { color: #0f172a; }
  .card, .chart-container { break-inside: avoid; }
}