/* Quietzenith — backyard astronomy primer. Midnight / rust / cream, chart-plate layout. */

:root {
  --midnight: #0b1220;
  --midnight-2: #111b30;
  --midnight-3: #182440;
  --cream: #f2e9d8;
  --cream-dim: #c9bfab;
  --cream-faint: rgba(242, 233, 216, 0.16);
  --rust: #c8562e;
  --ember: #e8865c;
  --rust-deep: #a8431f;
  --ink: #17213a;
  --ink-soft: #4a5470;
  --paper-line: rgba(23, 33, 58, 0.18);
  --serif: "Iowan Old Style", "Palatino Linotype", Palatino, "Book Antiqua", Georgia, "Times New Roman", serif;
  --mono: ui-monospace, "SF Mono", Menlo, Consolas, "Liberation Mono", monospace;
  --measure: 62ch;
  --wrap: 1180px;
  --gutter: clamp(20px, 4vw, 56px);
  --seam: clamp(72px, 10vw, 136px);
  --ease: cubic-bezier(0.4, 0, 0.2, 1);
}

*, *::before, *::after { box-sizing: border-box; }

html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }

body {
  margin: 0;
  background: var(--midnight);
  color: var(--cream);
  font-family: var(--serif);
  font-size: 1.0625rem;
  line-height: 1.55;
  background-image:
    radial-gradient(circle at 18% 12%, rgba(232, 134, 92, 0.08), transparent 38%),
    radial-gradient(circle at 82% 4%, rgba(242, 233, 216, 0.05), transparent 30%);
}

h1, h2, h3 { font-weight: 500; line-height: 1.12; margin: 0 0 0.5em; letter-spacing: -0.01em; }
h1 { font-size: clamp(1.9rem, 1.2rem + 2.6vw, 3.1rem); }
h2 { font-size: clamp(1.55rem, 1.1rem + 1.6vw, 2.25rem); }
h3 { font-size: 1.35rem; }
p { margin: 0 0 1em; }
a { color: inherit; text-decoration-color: var(--ember); text-underline-offset: 0.18em; }
a:hover { color: var(--ember); }
em { font-style: italic; }

:focus-visible {
  outline: 2px solid var(--ember);
  outline-offset: 3px;
  border-radius: 2px;
}

.skip {
  position: absolute; left: 12px; top: -60px; z-index: 20;
  padding: 8px 14px; background: var(--ember); color: var(--midnight);
  font-family: var(--mono); font-size: 0.85rem; text-decoration: none;
}
.skip:focus { top: 12px; }

.eyebrow {
  font-family: var(--mono);
  font-size: 0.74rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ember);
  margin-bottom: 1.1rem;
}
.eyebrow::before { content: "— "; color: var(--rust); }

/* Masthead ---------------------------------------------------------- */

.masthead {
  position: sticky; top: 0; z-index: 10;
  display: flex; align-items: center; gap: 24px; flex-wrap: wrap;
  padding: 14px var(--gutter);
  background: rgba(11, 18, 32, 0.88);
  border-bottom: 1px solid var(--cream-faint);
  backdrop-filter: blur(8px);
}
.brand {
  display: grid; grid-template-columns: auto auto; column-gap: 10px; align-items: center;
  text-decoration: none; margin-right: auto;
}
.brand-mark { width: 26px; height: 26px; grid-row: span 2; color: var(--ember); }
.brand span { font-size: 1.05rem; letter-spacing: 0.02em; line-height: 1.1; }
.brand small { font-family: var(--mono); font-size: 0.66rem; color: var(--cream-dim); letter-spacing: 0.08em; }
.nav ul { list-style: none; margin: 0; padding: 0; display: flex; gap: 4px; }
.nav a {
  display: block; padding: 8px 12px; font-family: var(--mono); font-size: 0.8rem;
  letter-spacing: 0.06em; text-decoration: none; border-bottom: 1px solid transparent;
}
.nav a:hover { border-bottom-color: var(--ember); }
.nav-toggle {
  display: none; align-items: center; gap: 10px;
  background: none; border: 1px solid var(--cream-faint); color: var(--cream);
  font-family: var(--mono); font-size: 0.8rem; letter-spacing: 0.08em; padding: 8px 12px; cursor: pointer;
}
.nav-toggle-bars {
  width: 18px; height: 11px; position: relative;
  border-top: 1.5px solid currentColor; border-bottom: 1.5px solid currentColor;
}
.nav-toggle-bars::after {
  content: ""; position: absolute; left: 0; right: 0; top: 4.5px; border-top: 1.5px solid currentColor;
}
.nav-toggle[aria-expanded="true"] .nav-toggle-bars { border-top-color: var(--ember); }

/* Hero: split studio ------------------------------------------------- */

.hero {
  max-width: var(--wrap); margin: 0 auto; padding: clamp(40px, 6vw, 72px) var(--gutter) 0;
  display: grid; grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr); gap: clamp(32px, 5vw, 72px);
  align-items: start;
}
.lede { font-size: 1.15rem; color: var(--cream-dim); max-width: var(--measure); }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin: 1.6rem 0 2.4rem; }

.button {
  display: inline-block; padding: 11px 18px; background: var(--ember); color: var(--midnight);
  font-family: var(--mono); font-size: 0.82rem; letter-spacing: 0.06em; text-decoration: none;
  border: 1px solid var(--ember); cursor: pointer; transition: background 0.15s var(--ease);
}
.button:hover { background: var(--cream); color: var(--midnight); border-color: var(--cream); }
.button-ghost { background: transparent; color: var(--cream); border-color: var(--cream-faint); }
.button-ghost:hover { background: transparent; color: var(--ember); border-color: var(--ember); }
.button-small { padding: 7px 12px; font-size: 0.74rem; }

.datastrip {
  display: grid; grid-template-columns: repeat(3, 1fr); margin: 0;
  border-top: 1px solid var(--cream-faint); border-bottom: 1px solid var(--cream-faint);
}
.datastrip > div { padding: 14px 14px 14px 0; border-right: 1px solid var(--cream-faint); }
.datastrip > div + div { padding-left: 14px; }
.datastrip > div:last-child { border-right: 0; }
.datastrip dt { font-family: var(--mono); font-size: 0.68rem; letter-spacing: 0.08em; color: var(--cream-dim); }
.datastrip dd { margin: 4px 0 0; font-size: 1.3rem; color: var(--ember); }

/* Chart figures ----------------------------------------------------- */

.chart { margin: 0; }
.chart svg {
  display: block; width: 100%; height: auto; color: var(--cream);
  background: var(--midnight-2); border: 1px solid var(--cream-faint);
}
.chart-labels text { font-family: var(--mono); font-size: 10.5px; fill: var(--cream); }
.chart-labels .label-note { fill: var(--cream-dim); font-size: 9.5px; }
.chart .pointer { stroke: var(--ember); }
.chart .polaris { fill: var(--ember); }
.chart figcaption {
  font-family: var(--mono); font-size: 0.74rem; line-height: 1.5; color: var(--cream-dim);
  padding: 10px 2px 0;
}
.chart figcaption b { color: var(--ember); font-weight: 500; }

/* Sections ---------------------------------------------------------- */

.section { padding-block: var(--seam); }
.section > * { max-width: var(--wrap); margin-inline: auto; padding-inline: var(--gutter); }
.section-head { margin-bottom: clamp(28px, 4vw, 48px); }
.section-intro { color: var(--cream-dim); max-width: var(--measure); }
.paper .section-intro { color: var(--ink-soft); }

/* Tabs -------------------------------------------------------------- */

.tabs { display: grid; grid-template-columns: 300px minmax(0, 1fr); gap: clamp(24px, 4vw, 64px); }
.tablist { display: flex; flex-direction: column; border-top: 1px solid var(--cream-faint); }
.tablist [role="tab"] {
  display: flex; gap: 14px; align-items: baseline; text-align: left;
  background: none; border: 0; border-bottom: 1px solid var(--cream-faint);
  color: var(--cream-dim); font-family: var(--serif); font-size: 1.05rem; line-height: 1.3;
  padding: 16px 12px 16px 0; cursor: pointer; position: relative;
}
.tablist [role="tab"]:hover { color: var(--cream); }
.tablist [role="tab"][aria-selected="true"] { color: var(--cream); }
.tablist [role="tab"][aria-selected="true"]::before {
  content: ""; position: absolute; left: -14px; top: 0; bottom: -1px; width: 3px; background: var(--ember);
}
.tab-index { font-family: var(--mono); font-size: 0.72rem; color: var(--ember); min-width: 1.6em; }
.panel h3 { padding-bottom: 12px; border-bottom: 1px solid var(--cream-faint); margin-bottom: 1rem; }
.panel p { max-width: var(--measure); }
.crossref { font-family: var(--mono); font-size: 0.8rem; color: var(--cream-dim); }
html:not(.js) .panel[hidden] { display: block; }
html:not(.js) .tablist { display: none; }

.mini-table, .season-table { border-collapse: collapse; width: 100%; margin: 1.2rem 0 1.4rem; }
.mini-table { max-width: 420px; font-size: 0.95rem; }
.mini-table caption, .season-table caption {
  text-align: left; font-family: var(--mono); font-size: 0.72rem; color: var(--cream-dim); padding-bottom: 8px;
}
.mini-table th, .mini-table td, .season-table th, .season-table td {
  text-align: left; padding: 9px 12px 9px 0; border-bottom: 1px solid var(--cream-faint); vertical-align: top;
}
.mini-table th, .season-table thead th {
  font-family: var(--mono); font-weight: 400; font-size: 0.72rem; letter-spacing: 0.08em;
  text-transform: uppercase; color: var(--ember);
}
.season-table tbody th { font-weight: 500; color: var(--ember); font-size: 1.1rem; }
.season-table td { color: var(--cream); font-size: 0.98rem; }
.season-table td:last-child { color: var(--cream-dim); }

/* Checklist --------------------------------------------------------- */

.checklist { display: grid; gap: 2px; margin-top: 1.4rem; border-top: 1px solid var(--cream-faint); }
.checklist-head {
  display: flex; justify-content: space-between; align-items: baseline; gap: 12px;
  font-family: var(--mono); font-size: 0.74rem; letter-spacing: 0.1em; text-transform: uppercase;
  color: var(--ember); padding: 12px 0 6px; margin: 0;
}
.checklist-head output { color: var(--cream-dim); letter-spacing: 0.04em; text-transform: none; }
.checklist label {
  display: grid; grid-template-columns: 20px 1fr; gap: 12px; align-items: start;
  padding: 9px 0; border-bottom: 1px solid var(--cream-faint); cursor: pointer; font-size: 0.98rem;
}
.checklist label:has(:checked) { color: var(--cream-dim); text-decoration: line-through; }
.checklist label:has(:checked) input { accent-color: var(--ember); }
.checklist input { width: 18px; height: 18px; margin: 4px 0 0; accent-color: var(--ember); }
.checklist .button { justify-self: start; margin-top: 14px; }

/* Worksheet (cream paper) ------------------------------------------- */

.paper {
  background: var(--cream); color: var(--ink);
  background-image:
    linear-gradient(var(--paper-line) 1px, transparent 1px),
    linear-gradient(90deg, var(--paper-line) 1px, transparent 1px);
  background-size: 48px 48px;
  background-position: center top;
  border-top: 3px solid var(--rust); border-bottom: 3px solid var(--rust);
}
.paper .eyebrow { color: var(--rust-deep); }
.paper .eyebrow::before { color: var(--rust); }
.paper :focus-visible { outline-color: var(--rust-deep); }
.worksheet {
  display: grid; grid-template-columns: minmax(0, 1fr) minmax(0, 1fr); gap: 20px clamp(24px, 4vw, 56px);
  background: var(--cream); border: 1px solid var(--ink); padding: clamp(20px, 3vw, 36px);
}
.presets { grid-column: 1 / -1; border: 0; margin: 0; padding: 0; display: flex; flex-wrap: wrap; gap: 8px; }
.presets legend {
  font-family: var(--mono); font-size: 0.72rem; letter-spacing: 0.1em; text-transform: uppercase;
  color: var(--rust-deep); padding: 0; margin-bottom: 10px; width: 100%;
}
.presets button {
  background: transparent; border: 1px solid var(--ink); color: var(--ink);
  font-family: var(--mono); font-size: 0.78rem; padding: 7px 12px; cursor: pointer;
}
.presets button:hover, .presets button[aria-pressed="true"] { background: var(--ink); color: var(--cream); }
.inputs { display: grid; gap: 14px; align-content: start; }
.inputs label {
  display: grid; grid-template-columns: 1fr auto; gap: 4px 10px; align-items: baseline;
  font-family: var(--mono); font-size: 0.78rem; letter-spacing: 0.04em;
}
.inputs label span { color: var(--ink-soft); font-size: 0.7rem; }
.inputs input {
  grid-column: 1 / -1; width: 100%; font: 1.25rem var(--serif); color: var(--ink);
  background: transparent; border: 0; border-bottom: 1.5px solid var(--ink); padding: 6px 0; border-radius: 0;
}
.inputs input:focus { outline: none; border-bottom-color: var(--rust); }
.inputs input:invalid, .inputs input[aria-invalid="true"] { border-bottom-color: var(--rust); color: var(--rust-deep); }
.readout {
  margin: 0; display: grid; grid-template-columns: 1fr 1fr; gap: 0;
  border: 1px solid var(--ink); align-self: start;
}
.readout > div {
  padding: 14px 16px; border-bottom: 1px solid var(--paper-line); border-right: 1px solid var(--paper-line);
}
.readout > div:nth-child(2n) { border-right: 0; }
.readout > div.wide { grid-column: 1 / -1; border-right: 0; border-bottom: 0; }
.readout dt { font-family: var(--mono); font-size: 0.68rem; letter-spacing: 0.1em; text-transform: uppercase; }
.readout dt { color: var(--ink-soft); }
.readout dd { margin: 4px 0 0; font-size: 1.6rem; line-height: 1.1; color: var(--ink); }
.readout .wide dd { color: var(--rust-deep); }
.verdict {
  grid-column: 1 / -1; margin: 0; padding: 12px 16px; border-left: 3px solid var(--rust);
  font-size: 1.02rem; color: var(--ink);
}
.verdict[data-state="warn"] { border-left-color: var(--ink); }
.method { grid-column: 1 / -1; font-size: 0.95rem; }
.method summary { cursor: pointer; font-family: var(--mono); font-size: 0.8rem; color: var(--rust-deep); }
.method ul { margin: 0.6rem 0 0; padding-left: 1.2rem; max-width: 70ch; }
.method li { margin-bottom: 0.4rem; }

/* Hand measures ----------------------------------------------------- */

.measures {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 0; margin: 0; border-top: 1px solid var(--cream-faint);
}
.measures > div {
  padding: 18px 18px 18px 0; border-right: 1px solid var(--cream-faint); border-bottom: 1px solid var(--cream-faint);
}
.measures > div + div { padding-left: 18px; }
.measures > div:last-child { border-right: 0; }
.measures dt { font-family: var(--mono); font-size: 0.72rem; letter-spacing: 0.08em; color: var(--cream-dim); }
.measures dd { margin: 6px 0 0; font-size: 2.2rem; line-height: 1; color: var(--ember); }
.measures dd.note { font-size: 0.95rem; color: var(--cream-dim); margin-top: 8px; }

/* Footer ------------------------------------------------------------ */

.footer { border-top: 1px solid var(--cream-faint); padding: clamp(40px, 6vw, 64px) var(--gutter) 32px; }
.footer-grid {
  max-width: var(--wrap); margin: 0 auto; display: grid;
  grid-template-columns: 1.2fr 1fr 0.6fr; gap: clamp(24px, 4vw, 56px);
}
.footer h2 {
  font-size: 1.05rem; font-family: var(--mono); letter-spacing: 0.08em; text-transform: uppercase; color: var(--ember);
}
.footer p { color: var(--cream-dim); font-size: 0.95rem; max-width: 46ch; }
.footer ul { list-style: none; margin: 0; padding: 0; display: grid; gap: 6px; }
.footer nav a { font-family: var(--mono); font-size: 0.8rem; }
.colophon {
  max-width: var(--wrap); margin: 40px auto 0; padding-top: 16px; border-top: 1px solid var(--cream-faint);
  font-family: var(--mono); font-size: 0.72rem; color: var(--cream-dim); letter-spacing: 0.04em;
}

/* Responsive -------------------------------------------------------- */

@media (max-width: 900px) {
  .hero { grid-template-columns: 1fr; }
  .tabs { grid-template-columns: 1fr; gap: 24px; }
  .tablist { flex-direction: row; overflow-x: auto; border-top: 0; border-bottom: 1px solid var(--cream-faint); }
  .tablist [role="tab"] { flex: 1 0 auto; border-bottom: 0; padding: 12px 14px 14px 0; font-size: 0.95rem; }
  .tablist [role="tab"][aria-selected="true"]::before {
    left: 0; right: 0; top: auto; bottom: 0; width: auto; height: 3px;
  }
  .worksheet { grid-template-columns: 1fr; }
  .measures { grid-template-columns: 1fr 1fr; }
  .measures > div:nth-child(2n) { border-right: 0; padding-left: 18px; }
  .measures > div:nth-child(2n + 1) { padding-left: 0; }
  .footer-grid { grid-template-columns: 1fr; }
}

@media (max-width: 640px) {
  body { font-size: 1rem; }
  .masthead { gap: 12px; }
  .brand small { display: none; }
  .nav-toggle { display: inline-flex; }
  .nav { display: none; flex-basis: 100%; }
  .nav[data-open] { display: block; }
  .nav ul { flex-direction: column; gap: 0; border-top: 1px solid var(--cream-faint); padding-top: 6px; }
  .nav a { padding: 12px 0; font-size: 0.9rem; border-bottom: 1px solid var(--cream-faint); }
  .datastrip { grid-template-columns: 1fr; }
  .datastrip > div { border-right: 0; border-bottom: 1px solid var(--cream-faint); padding-left: 0; }
  .datastrip > div:last-child { border-bottom: 0; }
  .datastrip dd { font-size: 1.15rem; }
  .readout { grid-template-columns: 1fr; }
  .readout > div { border-right: 0; }
  .readout dd { font-size: 1.4rem; }
  .season-table thead { position: absolute; width: 1px; height: 1px; overflow: hidden; clip: rect(0 0 0 0); }
  .season-table tr { display: block; padding: 14px 0; border-bottom: 1px solid var(--cream-faint); }
  .season-table th, .season-table td { display: block; border: 0; padding: 4px 0; }
  .season-table td::before {
    content: attr(data-label); display: block; font-family: var(--mono); font-size: 0.66rem;
    letter-spacing: 0.1em; text-transform: uppercase; color: var(--ember); margin-top: 6px;
  }
  .measures { grid-template-columns: 1fr; }
  .measures > div { border-right: 0; padding-left: 0 !important; }
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { transition: none !important; animation: none !important; }
}