/* Lunar Impact Flash Explorer — dark theme, layout, focus styles, reduced motion (design §9.1, §9.4–9.5). */

:root {
  --bg-0: #0a0a1a;
  --bg-1: #1a1a3a;
  --panel: rgba(12, 12, 32, 0.85);
  --panel-solid: #0c0c20;
  --border: rgba(255, 255, 255, 0.12);
  --text: #ececf4;
  --muted: #b4b8cc;
  --accent: #ffcc00;
  --accent-ink: #1a1400;
  --ok: #5fd38d;
  --bad: #ff7a7a;
  --warn: #ffb347;
  --radius: 10px;
  --header-h: 72px;
  font-family: system-ui, "Segoe UI", Roboto, sans-serif;
  color-scheme: dark;
}

* { box-sizing: border-box; }

html, body { margin: 0; padding: 0; }

body {
  min-height: 100vh;
  color: var(--text);
  background: linear-gradient(160deg, var(--bg-0) 0%, var(--bg-1) 100%) fixed;
  line-height: 1.45;
  font-size: 15px;
}

a { color: var(--accent); }
a:hover { text-decoration-thickness: 2px; }

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

h1, h2, h3 { line-height: 1.2; margin: 0.4em 0; }
h1 { font-size: 1.35rem; }
h2 { font-size: 1.1rem; }
h3 { font-size: 0.98rem; }

kbd {
  font: 0.75em ui-monospace, Consolas, monospace;
  border: 1px solid var(--border);
  border-radius: 4px;
  padding: 0 4px;
  color: var(--muted);
}

.noscript { padding: 1rem; background: var(--panel-solid); border-bottom: 1px solid var(--bad); }

/* ---------- header / footer ---------- */
.site-header {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem 1rem;
  padding: 0.5rem 1rem;
  min-height: var(--header-h);
  border-bottom: 1px solid var(--border);
}
.subtitle { margin: 0; color: var(--muted); font-size: 0.9rem; }
.header-actions { display: flex; align-items: center; gap: 0.5rem; flex-wrap: wrap; }

.site-footer {
  padding: 0.75rem 1rem 1.25rem;
  color: var(--muted);
  font-size: 0.85rem;
  border-top: 1px solid var(--border);
}

/* ---------- panels ---------- */
.panel {
  background: var(--panel);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border: 1px solid var(--border);
  border-radius: var(--radius);
}
@supports not ((backdrop-filter: blur(10px)) or (-webkit-backdrop-filter: blur(10px))) {
  .panel { background: var(--panel-solid); }
}

/* ---------- layout ---------- */
.layout {
  display: grid;
  gap: 0.75rem;
  padding: 0.75rem;
  grid-template-columns: minmax(0, 1fr);
  grid-template-areas: "view" "side" "panels";
}
#view { grid-area: view; display: flex; flex-direction: column; min-width: 0; }
#side { grid-area: side; padding: 0.5rem 0.75rem; min-width: 0; }
#panels { grid-area: panels; padding: 0.5rem 0.75rem 1rem; min-width: 0; }

#view-stage { position: relative; height: 50vh; min-height: 300px; border-radius: var(--radius) var(--radius) 0 0; overflow: hidden; background: #05050f; }

@media (min-width: 900px) {
  .layout {
    grid-template-columns: minmax(0, 1fr) 380px;
    grid-template-areas: "view side" "panels side";
    align-items: start;
  }
  #view-stage { height: 60vh; min-height: 360px; }
  #side {
    position: sticky;
    top: 0.75rem;
    overflow: auto;
    max-height: calc(100vh - var(--header-h) - 1.5rem);
  }
}

#view-canvas { position: absolute; inset: 0; }
#view-canvas canvas { display: block; width: 100%; height: 100%; }
#hud {
  position: absolute; left: 0.5rem; top: 0.5rem;
  font-size: 0.8rem; color: var(--text);
  background: rgba(5, 5, 15, 0.6); border-radius: 6px; padding: 0.25rem 0.5rem;
  font-variant-numeric: tabular-nums; pointer-events: none;
}
#hud:empty { display: none; }
.ir-legend {
  position: absolute; right: 0.5rem; bottom: 0.5rem; width: 200px;
  font-size: 0.75rem; color: var(--text);
  background: rgba(5, 5, 15, 0.6); border-radius: 6px; padding: 0.3rem 0.5rem; pointer-events: none;
}
.ir-legend[hidden] { display: none; }
.ir-legend .ir-bar { height: 10px; border-radius: 3px; margin-bottom: 0.2rem; }
#view-placeholder {
  position: absolute; inset: 0; display: flex; align-items: center; justify-content: center;
  padding: 1.5rem; text-align: center; color: var(--muted); font-size: 1rem;
  background: radial-gradient(circle at 50% 45%, #1d1d3a 0%, #05050f 70%);
}
#view-placeholder[hidden] { display: none; }

#toolbar {
  display: flex; flex-wrap: wrap; align-items: center; gap: 0.4rem 0.6rem;
  padding: 0.5rem 0.75rem; border-top: 1px solid var(--border);
}
.tb-item { display: inline-flex; align-items: center; gap: 0.35rem; font-size: 0.85rem; }
.tb-item.scrub input { width: 160px; }

#status {
  margin: 0; padding: 0.4rem 0.75rem 0.6rem; font-size: 0.85rem; color: var(--muted);
  border-top: 1px solid var(--border);
}
#status .st-icon { margin-right: 0.35em; }
#status.st-warning { color: var(--warn); }
#status.st-error { color: var(--bad); }

/* ---------- controls ---------- */
.btn, select, input[type="number"], button {
  font: inherit; color: var(--text);
  background: #16163a; border: 1px solid var(--border); border-radius: 6px;
  padding: 0.25rem 0.5rem;
}
.btn { cursor: pointer; }
.btn:hover:not(:disabled) { border-color: var(--accent); }
.btn:disabled, select:disabled, input:disabled { opacity: 0.5; cursor: not-allowed; }
.btn-accent { background: var(--accent); color: var(--accent-ink); border-color: var(--accent); }

#controls fieldset {
  border: 1px solid var(--border); border-radius: 8px; margin: 0.5rem 0; padding: 0.35rem 0.6rem 0.5rem;
}
#controls legend { padding: 0 0.3rem; color: var(--accent); font-weight: 600; font-size: 0.9rem; }
#controls details { margin: 0.5rem 0; }
#controls summary { cursor: pointer; color: var(--accent); font-weight: 600; padding: 0.25rem 0; }

.ctl { margin: 0.4rem 0; }
.ctl > label { display: block; font-size: 0.85rem; }
.ctl-row { display: flex; align-items: center; gap: 0.4rem; }
.ctl-row input[type="range"] { flex: 1 1 auto; min-width: 0; accent-color: var(--accent); }
.ctl-row input[type="number"] { width: 7.5em; font-variant-numeric: tabular-nums; }
.ctl-row .unit { color: var(--muted); font-size: 0.8rem; min-width: 2.5em; }
.ctl select { width: 100%; }
.ctl small { display: block; color: var(--muted); font-size: 0.75rem; }
.ctl.is-disabled > label { color: var(--muted); }

/* ---------- quick answers / outputs ---------- */
#quick { border-bottom: 1px solid var(--border); padding-bottom: 0.4rem; }
#quick-body p { margin: 0.3rem 0; font-size: 0.88rem; }
#quick-body strong { color: var(--accent); }

#outputs dl {
  display: grid; grid-template-columns: minmax(0, 42%) minmax(0, 1fr); gap: 0.15rem 0.5rem;
  font-size: 0.83rem; font-variant-numeric: tabular-nums; margin: 0.25rem 0;
}
#outputs dt { color: var(--muted); }
#outputs dd { margin: 0; overflow-wrap: anywhere; }
#outputs .greyed { color: var(--muted); }

.warnings { list-style: none; padding: 0; margin: 0.4rem 0; display: flex; flex-wrap: wrap; gap: 0.3rem; }
.warnings li, .chip {
  font-size: 0.75rem; color: var(--warn); border: 1px solid var(--warn); border-radius: 999px; padding: 0.05rem 0.5rem;
}

/* ---------- tabs ---------- */
.tablist { display: flex; flex-wrap: wrap; gap: 0.25rem; border-bottom: 1px solid var(--border); margin-bottom: 0.5rem; }
.tablist [role="tab"] {
  border: 1px solid transparent; border-bottom: none; border-radius: 8px 8px 0 0;
  background: transparent; padding: 0.4rem 0.9rem; cursor: pointer; color: var(--muted);
}
.tablist [role="tab"][aria-selected="true"] { color: var(--text); background: #16163a; border-color: var(--border); box-shadow: inset 0 -3px 0 var(--accent); }
[role="tabpanel"][hidden] { display: none; }
.panel-title { margin-top: 0.2rem; }

/* ---------- charts ---------- */
.chart { display: block; width: 100%; height: 300px; background: rgba(5, 5, 15, 0.55); border-radius: 8px; }
.chart-tall { height: 380px; }
.legend { display: flex; flex-wrap: wrap; gap: 0.25rem 0.9rem; font-size: 0.8rem; margin: 0.35rem 0 0.5rem; color: var(--muted); }
.legend-item { display: inline-flex; align-items: center; gap: 0.35rem; }
.legend-item svg { flex: none; }
.chart-note, .note { color: var(--muted); font-size: 0.82rem; }

/* ---------- tables ---------- */
.table-wrap { overflow-x: auto; }
table.data { border-collapse: collapse; width: 100%; font-size: 0.82rem; font-variant-numeric: tabular-nums; margin: 0.5rem 0; }
table.data caption { text-align: left; color: var(--muted); padding: 0.25rem 0; caption-side: top; }
table.data th, table.data td { border-bottom: 1px solid var(--border); padding: 0.25rem 0.4rem; text-align: left; vertical-align: top; }
table.data thead th { color: var(--muted); font-weight: 600; }
table.data tr.is-selected { background: rgba(240, 228, 66, 0.12); }
.yes { color: var(--ok); }
.no { color: var(--bad); }

#recommendation p, .answers p { margin: 0.35rem 0; }
.answers { border: 1px solid var(--border); border-radius: 8px; padding: 0.4rem 0.7rem; background: rgba(255, 204, 0, 0.05); }
.answers strong { color: var(--accent); }

/* ---------- equations ---------- */
.eq-card { border: 1px solid var(--border); border-radius: 8px; margin: 0.4rem 0; padding: 0 0.7rem; background: rgba(5, 5, 15, 0.35); }
.eq-card > summary { cursor: pointer; padding: 0.35rem 0; list-style-position: inside; }
.eq-card > summary h3 { display: inline; font-size: 0.95rem; }
.eq-card[open] { padding-bottom: 0.5rem; }
.eq-tex { overflow-x: auto; margin: 0.4rem 0; }
.eq-live { color: var(--accent); font-variant-numeric: tabular-nums; }
.eq-refs a { margin-right: 0.6rem; }
.eq-card table { border-collapse: collapse; font-size: 0.82rem; margin: 0.4rem 0; }
.eq-card th, .eq-card td { border-bottom: 1px solid var(--border); padding: 0.2rem 0.45rem; text-align: left; }
.eq-card caption { text-align: left; color: var(--muted); }
.no-katex .eq-tex, .no-katex .eq-sym { font-family: ui-monospace, Consolas, "Courier New", monospace; white-space: pre-wrap; color: var(--text); }

/* ---------- about / dialog ---------- */
#about ol { padding-left: 1.4rem; font-size: 0.85rem; }
#about li { margin: 0.2rem 0; }

dialog {
  color: var(--text); background: var(--panel-solid); border: 1px solid var(--border); border-radius: var(--radius);
  max-width: min(640px, 92vw); padding: 1rem 1.25rem;
}
dialog::backdrop { background: rgba(0, 0, 0, 0.6); }
.shortcuts { display: grid; grid-template-columns: auto 1fr; gap: 0.2rem 0.8rem; }
.shortcuts dd { margin: 0; }

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

@media (prefers-contrast: more) {
  .panel { background: var(--panel-solid); backdrop-filter: none; -webkit-backdrop-filter: none; border: 1px solid var(--muted); }
  .eq-card, #controls fieldset, table.data th, table.data td, .answers { border-color: var(--muted); }
}