/* ===========================================================================
   IRS notice decoder pages.

   Design language: a "decoded letter" dossier. Each page opens with a faux
   paper rendering of the notice's key fields beside the plain English decode,
   then a collection-ladder stepper showing where the letter sits in the IRS
   sequence, then per-notice content blocks. Each notice carries its own accent
   (severity-tinted, blue through red) via --nacc set inline on the wrapper.
   =========================================================================== */

.ndoc {
  --ink: #0f172a;
  --muted: #64748b;
  --line: #e6e8ec;
  --paper: #f8fafc;
  --nacc: #0ea5e9;
  --nacc-soft: color-mix(in srgb, var(--nacc) 9%, #fff);
  --nacc-ink: color-mix(in srgb, var(--nacc) 55%, #0f172a);
  color: var(--ink);
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  background: #fff;
  padding: 1.6rem 0 3rem;
}
.ndoc-wrap { max-width: 960px; margin: 0 auto; padding: 0 1.25rem; }

/* --- breadcrumbs ---------------------------------------------------------- */
.ndoc-crumbs { font-size: .85rem; color: var(--muted); margin: 0 0 1.6rem; }
.ndoc-crumbs a { color: var(--muted); text-decoration: none; }
.ndoc-crumbs a:hover { color: var(--nacc-ink); }
.ndoc-crumbs span[aria-hidden] { margin: 0 .45rem; }

/* --- dossier header: faux letter + decode -------------------------------- */
.ndoc-dossier { display: grid; grid-template-columns: 300px 1fr; gap: 2.2rem; align-items: start; margin: 0 0 1.6rem; }
@media (max-width: 760px) { .ndoc-dossier { grid-template-columns: 1fr; gap: 1.4rem; } }

.ndoc-letter {
  background: linear-gradient(178deg, #fdfdfc, #f7f7f4);
  border: 1px solid #ddd9d0;
  border-top: 5px solid var(--nacc);
  border-radius: 6px;
  box-shadow: 0 10px 28px -18px rgba(15, 23, 42, .35), 0 1px 3px rgba(15, 23, 42, .08);
  padding: 1.3rem 1.3rem 1.2rem;
  font-family: ui-monospace, "Cascadia Mono", "Segoe UI Mono", Consolas, monospace;
}
.ndoc-letter-agency { font-size: .62rem; letter-spacing: .08em; text-transform: uppercase; color: #8b8577; line-height: 1.5; margin: 0 0 1rem; }
.ndoc-letter-code { font-size: 1.45rem; font-weight: 700; letter-spacing: .02em; color: var(--ink); margin: 0 0 .2rem; }
.ndoc-letter-title { font-size: .78rem; color: #57534e; line-height: 1.45; margin: 0 0 1.1rem; }
.ndoc-letter-rows { border-top: 1px dashed #d6d3cb; }
.ndoc-letter-rows > div { display: flex; justify-content: space-between; gap: 1rem; padding: .5rem 0; border-bottom: 1px dashed #d6d3cb; font-size: .72rem; }
.ndoc-letter-rows span:first-child { color: #8b8577; text-transform: uppercase; letter-spacing: .05em; flex: none; }
.ndoc-letter-rows span:last-child { color: var(--ink); text-align: right; }
.ndoc-letter-chip { display: inline-block; margin-top: 1rem; font-size: .68rem; font-weight: 700; letter-spacing: .04em; color: var(--nacc-ink); background: var(--nacc-soft); border: 1px solid color-mix(in srgb, var(--nacc) 30%, #fff); border-radius: 999px; padding: 4px 11px; }

.ndoc-eyebrow { font-size: .72rem; font-weight: 800; letter-spacing: .13em; text-transform: uppercase; color: var(--nacc-ink); margin: 0 0 .55rem; }
.ndoc-decode h1 { font-size: clamp(1.55rem, 3.4vw, 2.15rem); line-height: 1.18; letter-spacing: -.02em; color: var(--ink); margin: 0 0 .9rem; }
.ndoc-answer { font-size: 1.06rem; line-height: 1.65; color: #334155; margin: 0; }
.ndoc-alias { font-size: .85rem; color: var(--muted); margin: .8rem 0 0; padding-left: .8rem; border-left: 3px solid var(--nacc); }

/* --- disclaimer ----------------------------------------------------------- */
.ndoc-disclaimer { background: #fffbeb; border: 1px solid #fde68a; border-radius: 10px; padding: .7rem 1rem; margin: 0 0 1.6rem; }
.ndoc-disclaimer p { font-size: .78rem; color: #92400e; line-height: 1.5; margin: 0; }

/* --- the collection ladder ------------------------------------------------ */
.ndoc-ladder { background: var(--paper); border: 1px solid var(--line); border-radius: 16px; padding: 1.4rem 1.5rem 1.5rem; margin: 0 0 1.5rem; }
.ndoc-ladder-h { font-size: 1.05rem; font-weight: 800; margin: 0 0 1.2rem; color: var(--ink); }
.ndoc-rungs { list-style: none; display: flex; margin: 0; padding: 0; gap: 0; }
.ndoc-rungs li { flex: 1; position: relative; padding: 0 .6rem 0 0; }
.ndoc-rungs li::before { content: ""; position: absolute; top: 7px; left: 18px; right: 0; height: 2px; background: #d8dde4; }
.ndoc-rungs li:last-child::before { display: none; }
.ndoc-rungs li::after { content: ""; position: absolute; top: 2px; left: 0; width: 12px; height: 12px; border-radius: 50%; background: #fff; border: 3px solid #c3cad4; }
.ndoc-rungs li.is-here::after { border-color: var(--nacc); background: var(--nacc); box-shadow: 0 0 0 5px var(--nacc-soft); }
.ndoc-rungs a { text-decoration: none; }
.ndoc-rung-code { display: block; margin-top: 1.5rem; font-size: .78rem; font-weight: 800; color: var(--ink); letter-spacing: .01em; }
.ndoc-rungs a .ndoc-rung-code { color: var(--nacc-ink); text-decoration: underline; text-decoration-color: color-mix(in srgb, var(--nacc) 40%, #fff); text-underline-offset: 3px; }
.ndoc-rung-label { display: block; font-size: .7rem; color: var(--muted); line-height: 1.35; margin-top: .15rem; }
.ndoc-here { display: inline-block; margin-top: .4rem; font-size: .62rem; font-weight: 800; letter-spacing: .09em; text-transform: uppercase; color: #fff; background: var(--nacc); border-radius: 999px; padding: 2px 8px; }
@media (max-width: 700px) {
  .ndoc-rungs { flex-direction: column; gap: 0; }
  .ndoc-rungs li { padding: 0 0 1.1rem 1.9rem; }
  .ndoc-rungs li::before { top: 16px; left: 5px; right: auto; bottom: -2px; width: 2px; height: auto; }
  .ndoc-rungs li::after { top: 1px; }
  .ndoc-rung-code { margin-top: 0; }
}

/* --- content blocks ------------------------------------------------------- */
.nb { margin: 0 0 1.5rem; }
.nb h2 { font-size: 1.22rem; font-weight: 800; color: var(--ink); letter-spacing: -.01em; margin: 0 0 .85rem; }

.nb-plain { background: #fff; border: 1px solid var(--line); border-radius: 16px; box-shadow: 0 1px 2px rgba(15,23,42,.04); padding: clamp(1.4rem, 3vw, 1.9rem) clamp(1.5rem, 3.5vw, 2rem); }
.nb-plain h2 { padding-left: .9rem; border-left: 4px solid var(--nacc); }
.nb-plain p { font-size: 1rem; line-height: 1.7; color: #334155; margin: 0 0 1rem; }
.nb-plain p:last-child { margin-bottom: 0; }

.nb-panel { background: #0b1220; border-radius: 16px; padding: clamp(1.5rem, 4vw, 2.1rem); position: relative; overflow: hidden; }
.nb-panel::before { content: ""; position: absolute; inset: 0 auto 0 0; width: 6px; background: var(--nacc); }
.nb-panel .nb-kicker { font-size: .7rem; font-weight: 800; letter-spacing: .12em; text-transform: uppercase; color: color-mix(in srgb, var(--nacc) 60%, #fff); margin: 0 0 .5rem; }
.nb-panel h2 { color: #fff; }
.nb-panel p { color: #cbd5e1; font-size: .99rem; line-height: 1.65; margin: 0; }

.nb-mythfact { background: #fff; border: 1px solid var(--line); border-radius: 16px; box-shadow: 0 1px 2px rgba(15,23,42,.04); padding: clamp(1.4rem, 3vw, 1.9rem) clamp(1.5rem, 3.5vw, 2rem); }
.nb-mf-row { display: grid; grid-template-columns: 1fr; gap: .4rem 0; padding: 1.05rem 0; border-top: 1px solid var(--line); }
.nb-mf-row:first-of-type { border-top: 0; padding-top: 0; }
@media (min-width: 720px) { .nb-mf-row { grid-template-columns: 1fr 1.15fr; gap: 0 2rem; align-items: start; } }
.nb-mf-myth { color: var(--muted); font-size: .93rem; line-height: 1.55; position: relative; padding-left: 1.5rem; }
.nb-mf-myth::before { content: "\201C"; position: absolute; left: 0; top: .15rem; font-size: 1.3rem; font-weight: 800; color: #cbd5e1; line-height: 1; }
.nb-mf-fact { color: var(--ink); font-size: .98rem; line-height: 1.6; font-weight: 500; position: relative; padding-left: 1.5rem; }
.nb-mf-fact::before { content: ""; position: absolute; left: 0; top: .5rem; width: 9px; height: 9px; border-radius: 50%; background: var(--nacc); }

.nb-decision { background: var(--paper); border: 1px solid var(--line); border-radius: 16px; padding: clamp(1.4rem, 3vw, 1.9rem) clamp(1.5rem, 3.5vw, 2rem); }
.nb-paths { display: grid; grid-template-columns: repeat(auto-fit, minmax(230px, 1fr)); gap: 1rem; }
.nb-path { background: #fff; border: 1px solid var(--line); border-top: 4px solid var(--nacc); border-radius: 12px; padding: 1.1rem 1.2rem; }
.nb-path h3 { font-size: 1rem; font-weight: 800; color: var(--ink); margin: 0 0 .45rem; }
.nb-path p { font-size: .9rem; color: #475569; line-height: 1.55; margin: 0 0 .6rem; }
.nb-path a { font-size: .88rem; font-weight: 700; color: var(--nacc-ink); text-decoration: none; border-bottom: 2px solid var(--nacc); padding-bottom: 1px; }
.nb-path a:hover { color: var(--ink); border-bottom-color: var(--ink); }

.nb-checklist { background: var(--paper); border: 1px solid var(--line); border-radius: 16px; padding: clamp(1.4rem, 3.5vw, 2rem); }
.nb-checklist ol { list-style: none; counter-reset: step; margin: 0; padding: 0; }
.nb-checklist li { counter-increment: step; position: relative; padding: 0 0 1rem 3rem; }
.nb-checklist li:last-child { padding-bottom: 0; }
.nb-checklist li::before { content: counter(step); position: absolute; left: 0; top: -2px; width: 2rem; height: 2rem; border-radius: 50%; background: var(--nacc); color: #fff; font-weight: 800; font-size: .9rem; display: grid; place-items: center; }
.nb-checklist li p { margin: .3rem 0 0; font-size: .96rem; color: #334155; line-height: 1.55; }

.nb-penaltybox { background: #fff; border: 1px solid var(--line); border-radius: 16px; box-shadow: 0 1px 2px rgba(15,23,42,.04); padding: clamp(1.4rem, 3vw, 1.9rem) clamp(1.5rem, 3.5vw, 2rem); }
.nb-penaltybox dl { margin: 0; }
.nb-penaltybox dl > div { display: grid; grid-template-columns: 200px 1fr; gap: 1.2rem; padding: .75rem 0; border-top: 1px solid var(--line); align-items: baseline; }
.nb-penaltybox dl > div:first-of-type { border-top: 0; padding-top: 0; }
@media (max-width: 560px) { .nb-penaltybox dl > div { grid-template-columns: 1fr; gap: .15rem; } }
.nb-penaltybox dt { font-size: .92rem; font-weight: 700; color: var(--nacc-ink); }
.nb-penaltybox dd { margin: 0; font-size: .95rem; color: #334155; line-height: 1.55; }

.nb-passport { background: var(--nacc-soft); border: 1px solid color-mix(in srgb, var(--nacc) 22%, #fff); border-left: 6px solid var(--nacc); border-radius: 4px 16px 16px 4px; padding: clamp(1.4rem, 3.5vw, 1.9rem) clamp(1.5rem, 4vw, 2.1rem); }
.nb-passport p { font-size: .98rem; color: #1e293b; line-height: 1.65; margin: 0; }

.nb-cdp { background: #fff; border: 1px solid var(--line); border-radius: 16px; box-shadow: 0 1px 2px rgba(15,23,42,.04); padding: clamp(1.4rem, 3vw, 1.9rem) clamp(1.5rem, 3.5vw, 2rem); }
.nb-cdp-intro { font-size: .96rem; color: #475569; line-height: 1.6; margin: 0 0 1rem; }
.nb-cdp-scroll { overflow-x: auto; }
.nb-cdp table { width: 100%; border-collapse: collapse; min-width: 520px; }
.nb-cdp thead th { font-size: .76rem; text-transform: uppercase; letter-spacing: .05em; color: var(--muted); text-align: left; padding: 0 1rem .6rem; }
.nb-cdp thead th:nth-child(2) { color: var(--nacc-ink); }
.nb-cdp tbody th { text-align: left; font-weight: 600; color: var(--ink); font-size: .9rem; padding: .8rem 1rem; border-top: 1px solid var(--line); vertical-align: top; }
.nb-cdp tbody td { font-size: .9rem; color: #334155; padding: .8rem 1rem; border-top: 1px solid var(--line); vertical-align: top; }
.nb-cdp tbody td:first-of-type { border-left: 3px solid var(--nacc); background: var(--nacc-soft); font-weight: 600; color: var(--nacc-ink); }

.nb-pointer { background: var(--nacc-soft); border: 1px solid color-mix(in srgb, var(--nacc) 22%, #fff); border-radius: 16px; padding: clamp(1.2rem, 3vw, 1.6rem) clamp(1.4rem, 3.5vw, 1.9rem); }
.nb-pointer .nb-kicker { font-size: .7rem; font-weight: 800; letter-spacing: .12em; text-transform: uppercase; color: var(--nacc-ink); margin: 0 0 .5rem; }
.nb-ptr-text { font-size: .96rem; color: #1e293b; line-height: 1.6; margin: 0 0 .7rem; max-width: 62ch; }
.nb-ptr-link { display: inline-block; font-weight: 800; font-size: .94rem; color: var(--nacc-ink); text-decoration: none; border-bottom: 2px solid var(--nacc); padding-bottom: 2px; }
.nb-ptr-link:hover { color: var(--ink); border-bottom-color: var(--ink); }

.nb-note { font-size: .8rem; color: var(--muted); line-height: 1.55; margin: .9rem 0 0; }
.nb-note a { color: var(--nacc-ink); }

/* --- faq ------------------------------------------------------------------ */
.nb-faq { background: #fff; border: 1px solid var(--line); border-radius: 16px; box-shadow: 0 1px 2px rgba(15,23,42,.04); padding: clamp(1.4rem, 3vw, 1.9rem) clamp(1.5rem, 3.5vw, 2rem); }
.nb-faq details { border-bottom: 1px solid var(--line); }
.nb-faq details:last-child { border-bottom: 0; }
.nb-faq summary { cursor: pointer; list-style: none; padding: 1rem 2rem 1rem 0; font-weight: 600; color: var(--ink); font-size: 1rem; position: relative; }
.nb-faq summary::-webkit-details-marker { display: none; }
.nb-faq summary::after { content: "+"; position: absolute; right: 0; top: .85rem; font-size: 1.4rem; font-weight: 400; color: var(--nacc); }
.nb-faq details[open] summary::after { content: "\2212"; }
.nb-faq details p { margin: 0 0 1.1rem; color: #334155; line-height: 1.65; font-size: .96rem; }

/* --- sources -------------------------------------------------------------- */
.nb-sources { background: var(--paper); border: 1px solid var(--line); border-radius: 12px; padding: 1rem 1.2rem; }
.nb-sources p { font-size: .78rem; color: var(--muted); line-height: 1.6; margin: 0; }
.nb-sources a { color: var(--nacc-ink); }

/* --- cta ------------------------------------------------------------------ */
.ndoc-cta { text-align: center; background: #0b1220; border-radius: 16px; padding: clamp(1.8rem, 4vw, 2.6rem) 1.5rem; }
.ndoc-cta h2 { color: #fff; font-size: 1.35rem; margin: 0 0 .5rem; letter-spacing: -.01em; }
.ndoc-cta p { color: #cbd5e1; font-size: .95rem; line-height: 1.6; margin: 0 auto .5rem; max-width: 54ch; }
.ndoc-cta-btn { display: inline-block; margin: .8rem 0 .4rem; background: var(--nacc); color: #fff; font-weight: 800; font-size: .98rem; text-decoration: none; border-radius: 10px; padding: .8rem 1.6rem; }
.ndoc-cta-btn:hover { filter: brightness(1.08); }
.ndoc-cta-note { font-size: .74rem !important; color: #94a3b8 !important; }
.ndoc-cta-note a { color: #7dd3fc; }

/* ===========================================================================
   Hub page
   =========================================================================== */
.nhub-hero { margin: 0 0 1.6rem; max-width: 720px; }
.nhub-hero h1 { font-size: clamp(1.7rem, 3.8vw, 2.4rem); line-height: 1.15; letter-spacing: -.02em; color: var(--ink); margin: 0 0 .8rem; }
.nhub-lede { font-size: 1.05rem; line-height: 1.65; color: #334155; margin: 0; }
.nhub-ladder-note { font-size: .85rem; color: var(--muted); line-height: 1.55; margin: 1.1rem 0 0; }

.nhub-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(280px, 1fr)); gap: 1rem; margin: 0 0 1.8rem; }
.nhub-card { display: block; background: #fff; border: 1px solid var(--line); border-top: 5px solid var(--nacc); border-radius: 14px; box-shadow: 0 1px 2px rgba(15,23,42,.04); padding: 1.2rem 1.3rem; text-decoration: none; transition: box-shadow .15s, transform .15s; }
.nhub-card:hover { box-shadow: 0 10px 28px -18px rgba(15,23,42,.4); transform: translateY(-2px); }
.nhub-card-top { display: flex; justify-content: space-between; align-items: center; gap: .8rem; margin: 0 0 .5rem; }
.nhub-card-code { font-family: ui-monospace, "Cascadia Mono", Consolas, monospace; font-size: 1.15rem; font-weight: 700; color: var(--ink); }
.nhub-card-chip { font-size: .62rem; font-weight: 700; letter-spacing: .03em; color: var(--nacc-ink); background: var(--nacc-soft); border-radius: 999px; padding: 3px 9px; text-align: right; }
.nhub-card-title { font-size: .82rem; font-weight: 600; color: var(--muted); margin: 0 0 .55rem; }
.nhub-card-desc { font-size: .89rem; color: #475569; line-height: 1.55; margin: 0 0 .7rem; }
.nhub-card-deadline { font-size: .78rem; font-weight: 700; color: var(--nacc-ink); margin: 0; padding-top: .6rem; border-top: 1px dashed var(--line); }

.nhub-glossary { background: var(--paper); border: 1px solid var(--line); border-radius: 16px; padding: clamp(1.4rem, 3vw, 1.9rem) clamp(1.5rem, 3.5vw, 2rem); margin: 0 0 1.5rem; }
.nhub-glossary h2 { font-size: 1.15rem; font-weight: 800; margin: 0 0 1rem; }
.nhub-glossary dl { margin: 0; }
.nhub-glossary dl > div { display: grid; grid-template-columns: 130px 1fr; gap: 1rem; padding: .6rem 0; border-top: 1px solid var(--line); }
.nhub-glossary dl > div:first-of-type { border-top: 0; padding-top: 0; }
@media (max-width: 560px) { .nhub-glossary dl > div { grid-template-columns: 1fr; gap: .1rem; } }
.nhub-glossary dt { font-family: ui-monospace, "Cascadia Mono", Consolas, monospace; font-size: .85rem; font-weight: 700; color: var(--ink); }
.nhub-glossary dd { margin: 0; font-size: .89rem; color: #475569; line-height: 1.55; }
.nhub-glossary dd a { color: var(--nacc-ink); font-weight: 600; }
.nhub-glossary-note { font-size: .8rem; color: var(--muted); margin: 1rem 0 0; }
.nhub-glossary-note a { color: var(--nacc-ink); }