:root {
  --ink: #152033;
  --muted: #5d6878;
  --line: #dbe1e9;
  --paper: #ffffff;
  --canvas: #eef1f5;
  --nav: #e8ebef;
  --blue: #174f8f;
  --blue-dark: #0d315c;
  --gold: #c79b38;
}

* { box-sizing: border-box; }
html, body { margin: 0; min-height: 100%; }
body { background: var(--canvas); color: var(--ink); font-family: Inter, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif; }
.container { display: grid; grid-template-columns: clamp(190px, 15vw, 240px) minmax(0, 1fr); gap: 6px; min-height: 100vh; padding: 6px; }
.left-section { background: var(--nav); border: 1px solid #d3d8df; border-radius: 12px; padding: 12px; }
.league-logo { display: block; margin-bottom: 12px; }
.league-logo img { display: block; width: 100%; height: auto; }
.nav-title { color: var(--muted); font-size: .78rem; letter-spacing: .09em; margin: 16px 5px 6px; text-align: center; text-transform: uppercase; }
.nav-list { list-style: none; margin: 0; padding: 0; }
.nav-list a { border-radius: 8px; color: #111; display: block; font-size: .78rem; padding: 5px 9px; text-decoration: none; }
.nav-list a:hover, .nav-list a:focus { background: rgba(0,0,0,.07); }
.nav-list a.active { background: #fff; border-left: 4px solid var(--gold); color: var(--blue-dark); font-weight: 700; }
.nav-group + .nav-group { border-top: 1px solid rgba(0,0,0,.1); margin-top: 12px; padding-top: 2px; }
.has-flyout { position: relative; }
.flyout { background: #fff; border-radius: 12px; box-shadow: 0 10px 30px rgba(0,0,0,.18); color: #111; display: none; left: 100%; margin-left: 10px; max-height: 70vh; overflow: auto; padding: 10px; position: absolute; top: 0; width: 300px; z-index: 1000; }
.has-flyout:hover .flyout, .has-flyout:focus-within .flyout { display: block; }
.flyout-list { display: grid; gap: 4px 12px; grid-template-columns: 1fr 1fr; list-style: none; margin: 0; padding: 0; }
.flyout-heading { color: #666; font-size: 12px; font-weight: 700; grid-column: 1 / -1; margin: 8px 0 4px; pointer-events: none; text-transform: uppercase; }
.flyout-list a { padding: 8px 10px; }
.right-section { background: var(--paper); border-radius: 12px; box-shadow: 0 2px 9px rgba(20,31,48,.09); min-width: 0; overflow: hidden; }
.hero { background: linear-gradient(125deg, var(--blue-dark), var(--blue)); color: #fff; padding: 24px clamp(24px, 2.5vw, 46px) 20px; position: relative; }
.hero::after { background: var(--gold); bottom: 0; content: ""; height: 5px; left: 0; position: absolute; width: 34%; }
.eyebrow { color: #d8e7fa; font-size: .72rem; font-weight: 700; letter-spacing: .12em; margin: 0 0 6px; text-transform: uppercase; }
.hero h1 { font-family: inherit; font-size: clamp(1.9rem, 2.7vw, 2.9rem); letter-spacing: -.025em; line-height: 1.05; margin: 0; }
.hero h1 span { color: #edc76f; }
.hero-copy { font-size: .98rem; line-height: 1.5; margin: 10px 0; max-width: none; }
.hero-note { background: rgba(255,255,255,.1); border-left: 3px solid #edc76f; font-size: .88rem; max-width: none; padding: 8px 12px; }
.guide { margin: 0 auto; max-width: none; padding: 24px clamp(20px, 2.5vw, 46px) 48px; width: 100%; }
.guide section { margin: 0 0 42px; scroll-margin-top: 20px; }
.guide h2 { border-bottom: 1px solid var(--line); font-family: inherit; font-size: 1.65rem; margin: 0 0 16px; padding-bottom: 9px; }
.guide h2::after { background: var(--gold); content: ""; display: block; height: 3px; margin-top: 9px; width: 45px; }
.guide h3 { font-size: 1rem; margin: 0 0 8px; }
.guide p, .guide li { line-height: 1.68; }
.credit-card { background: #f4f8fd; border: 1px solid #cdddec; border-radius: 12px; padding: 22px; }
.credit-card h2 { color: var(--blue-dark); }
.source-link { color: var(--blue); font-weight: 700; }
.steps { counter-reset: av-step; list-style: none; padding: 0; }
.steps li { border-left: 1px solid var(--line); margin-left: 17px; padding: 0 0 18px 28px; position: relative; }
.steps li::before { align-items: center; background: var(--blue); border-radius: 50%; color: white; content: counter(av-step); counter-increment: av-step; display: flex; font-size: .75rem; font-weight: 800; height: 34px; justify-content: center; left: -18px; position: absolute; top: -2px; width: 34px; }
.formula-grid, .callout-grid, .definition-grid { display: grid; gap: 16px; grid-template-columns: repeat(2, minmax(0, 1fr)); }
.formula-card, .callout, .definition-grid > div { background: #fafbfc; border: 1px solid var(--line); border-radius: 10px; padding: 18px; }
code { background: #edf1f6; border-radius: 5px; color: #173a66; display: inline-block; font-family: "Cascadia Code", Consolas, monospace; font-size: .85em; line-height: 1.55; padding: 3px 6px; }
.formula-card code { display: block; white-space: normal; }
.table-wrap { border: 1px solid var(--line); border-radius: 10px; overflow-x: auto; }
table { border-collapse: collapse; font-size: .91rem; width: 100%; }
th { background: var(--blue-dark); color: #fff; font-size: .76rem; letter-spacing: .06em; padding: 13px; text-align: left; text-transform: uppercase; }
td { border-bottom: 1px solid var(--line); line-height: 1.5; padding: 13px; vertical-align: top; }
tbody tr:nth-child(even) { background: #f7f9fb; }
tbody tr:last-child td { border-bottom: 0; }
td:first-child { color: var(--blue-dark); white-space: nowrap; }
.limits { background: #fff9eb; border: 1px solid #ead7a5; border-radius: 12px; padding: 22px; }
.method-note { background: #f4f8fd; border-left: 3px solid var(--blue); margin-top: 16px; padding: 12px 14px; }
.limits li { margin-bottom: 7px; }
.bottom-line { border-top: 1px solid #ead7a5; margin-top: 20px; padding-top: 16px; }
footer { border-top: 1px solid var(--line); color: var(--muted); font-size: .78rem; padding: 18px 30px; text-align: center; }

@media (max-width: 800px) {
  .container { display: block; padding: 0; }
  .left-section { border-radius: 0; padding: 8px 14px; }
  .league-logo { margin: 0 auto 6px; width: 92px; }
  .left-section nav { display: flex; gap: 12px; overflow-x: auto; }
  .nav-group { min-width: 180px; }
  .nav-group + .nav-group { border-left: 1px solid rgba(0,0,0,.1); border-top: 0; margin: 0; padding: 0 0 0 12px; }
  .right-section { border-radius: 0; }
  .formula-grid, .callout-grid, .definition-grid { grid-template-columns: 1fr; }
}