/* EM Spectrum Explorer — house style adapted from space-teaching-aid
   (reference/). Same palette hexes as not-pc-imat / skew-t / space; variable
   naming follows space (the newest of the family). Dark-only. */

:root {
  color-scheme: dark;
  --void: #02070c;
  --surface: #020a10;
  --surface-2: #05131d;
  --surface-3: #09202b;
  --line: rgba(132, 194, 214, 0.18);
  --line-strong: rgba(132, 220, 235, 0.34);
  --text: #edf8fb;
  --muted: #8da8b3;
  --quiet: #668794;
  --cyan: #29d4e3;
  --cyan-bright: #5ce8f1;
  --amber: #f5c96a;
  --coral: #ff7b78;
  --violet: #a98cff;
  --mint: #76e6a5;
  --radius-lg: 20px;
  --radius-md: 14px;
  --radius-sm: 10px;
  --topbar-height: 68px;
  --rail-width: clamp(340px, 30vw, 440px);
  --ease-out: cubic-bezier(0.2, 0.8, 0.2, 1);
  /* Canvas engine hooks (read by spectrum.js) */
  --sv-ink: #edf8fb;
  --sv-muted: #8da8b3;
  --sv-line: rgba(132, 194, 214, 0.24);
  --sv-hi: #5ce8f1;
  --sv-label: #041019;
}

* { box-sizing: border-box; }
html, body { margin: 0; padding: 0; }

body {
  min-height: 100vh;
  color: var(--text);
  background:
    radial-gradient(circle at 14% -12%, rgba(24, 127, 151, 0.2), transparent 38%),
    var(--void);
  font-family: Inter, ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", sans-serif;
  font-synthesis: none;
  text-rendering: optimizeLegibility;
}

a { color: var(--cyan-bright); }

/* ---------- top bar ---------- */

.topbar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 14px;
  min-height: var(--topbar-height);
  padding: 8px 18px;
  border-bottom: 1px solid var(--line);
  background: rgba(2, 10, 16, 0.86);
  position: sticky; top: 0; z-index: 30;
  backdrop-filter: blur(6px);
}

.brand { display: flex; align-items: center; gap: 12px; text-decoration: none; color: inherit; }
.brand-mark { width: 40px; height: 40px; display: grid; place-items: center; }
.brand-mark svg { width: 40px; height: 40px; }
.brand h1 { margin: 0; font-size: 1.06rem; font-weight: 720; letter-spacing: -0.02em; }

.eyebrow {
  display: block; margin: 0 0 3px;
  color: var(--cyan);
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.62rem; font-weight: 600;
  letter-spacing: 0.14em; line-height: 1.2; text-transform: uppercase;
}

.header-actions { display: flex; align-items: center; gap: 9px; }

.header-button, .icon-button {
  display: inline-flex; min-height: 40px; align-items: center; justify-content: center;
  gap: 8px; padding: 0 13px;
  border: 1px solid var(--line); border-radius: 11px;
  color: var(--text); background: rgba(9, 32, 43, 0.55);
  font: inherit; font-size: 0.8rem; font-weight: 600;
  text-decoration: none; cursor: pointer;
}
.icon-button { width: 42px; padding: 0; border-radius: 50%; font-style: italic; font-weight: 740; color: var(--cyan-bright); }
.header-button:hover, .icon-button:hover { border-color: var(--line-strong); }

/* ---------- search ---------- */

.searchbox { position: relative; }
.searchbox input {
  min-width: clamp(180px, 24vw, 320px); min-height: 40px;
  padding: 0 13px; border: 1px solid var(--line); border-radius: 11px;
  color: var(--text); background: var(--surface-2);
  font: inherit; font-size: 0.82rem;
}
.searchbox input:focus { outline: none; border-color: var(--line-strong); }
#searchResults {
  display: none; position: absolute; top: calc(100% + 6px); left: 0; right: 0;
  margin: 0; padding: 6px; list-style: none; z-index: 40;
  max-height: 340px; overflow-y: auto;
  border: 1px solid var(--line-strong); border-radius: var(--radius-sm);
  background: var(--surface-2); box-shadow: 0 20px 52px rgba(0, 7, 13, 0.42);
}
#searchResults.open { display: block; }
#searchResults li { padding: 7px 9px; border-radius: 7px; font-size: 0.8rem; }
#searchResults li:hover { background: var(--surface-3); }
#searchResults a { color: var(--text); text-decoration: none; font-weight: 600; }
#searchResults .meta { color: var(--quiet); font-size: 0.72rem; }

/* ---------- app shell ---------- */

.app-shell {
  display: grid;
  grid-template-columns: minmax(0, 1fr) var(--rail-width);
  gap: 16px;
  padding: 16px 18px 40px;
  align-items: start;
}

.strip-col { min-width: 0; }

.hud-row {
  display: flex; align-items: baseline; gap: 14px;
  margin: 2px 4px 8px; min-height: 20px;
}
.crumb {
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.7rem; font-weight: 600; letter-spacing: 0.1em; text-transform: uppercase;
  color: var(--cyan); white-space: nowrap;
}
.readout {
  font-family: "IBM Plex Mono", monospace;
  font-size: 0.72rem; color: var(--muted); white-space: nowrap; overflow: hidden;
  flex: 1;
}
.hud-hint { color: var(--quiet); font-size: 0.66rem; white-space: nowrap; overflow: hidden; text-overflow: ellipsis; }

.preset-row { display: flex; flex-wrap: wrap; gap: 2px 4px; margin: 8px 0 4px; min-height: 24px; }

.spectrum-wrap { padding: 0; position: relative; }
.spectrum-wrap canvas { display: block; cursor: crosshair; }

.bar-controls { display: flex; gap: 5px; align-self: center; }
.bar-controls button {
  width: 26px; height: 26px; border: 1px solid var(--line); border-radius: 8px;
  color: var(--cyan-bright); background: rgba(9, 32, 43, 0.55);
  font: 700 0.9rem/1 "IBM Plex Mono", monospace; cursor: pointer;
}
.bar-controls button:hover { border-color: var(--line-strong); background: var(--surface-3); }

.bar-hint {
  position: absolute; top: 44px; left: 50%; transform: translateX(-50%); z-index: 5;
  padding: 7px 14px; border: 1px solid var(--line-strong); border-radius: 999px;
  color: var(--text); background: rgba(2, 10, 16, 0.9);
  font-size: 0.76rem; white-space: nowrap;
  box-shadow: 0 12px 30px rgba(0, 7, 13, 0.28);
  animation: hint-pulse 2.4s ease-in-out infinite;
}
.bar-hint strong { color: var(--cyan-bright); }
@keyframes hint-pulse { 0%, 100% { opacity: 0.85; } 50% { opacity: 1; } }

.preset-tag {
  align-self: center; margin-right: 4px;
  font-family: "IBM Plex Mono", monospace; font-size: 0.6rem; font-weight: 600;
  letter-spacing: 0.14em; color: var(--quiet);
}

/* ---------- chips & filters ---------- */

.chip {
  display: inline-flex; min-height: 24px; align-items: center; gap: 5px;
  padding: 2px 10px; border: 1px solid transparent; border-radius: 999px;
  color: var(--quiet); background: transparent;
  font: inherit; font-size: 0.68rem; font-weight: 650; letter-spacing: 0.03em;
  white-space: nowrap; cursor: pointer;
}
.chip:hover { color: var(--text); border-color: var(--line); }
.chip.on { color: var(--cyan-bright); border-color: var(--line); background: rgba(24, 89, 103, 0.28); }
.chip.cat.on { color: var(--text); border-color: var(--line); box-shadow: inset 2px 0 0 0 var(--chip, var(--line-strong)); }
.chip.preset {
  font-family: "IBM Plex Mono", monospace; font-size: 0.66rem; font-weight: 600;
  letter-spacing: 0.08em; text-transform: uppercase; color: var(--muted);
}
.chip.preset:hover { color: var(--cyan-bright); border-color: var(--line); }
.chip.meta-chip { font-style: italic; }

.filters {
  margin: 0 0 12px; border: 1px solid var(--line); border-radius: var(--radius-md);
  background: var(--surface); padding: 0 12px;
}
.filters summary {
  cursor: pointer; padding: 9px 2px; font-size: 0.78rem; font-weight: 650; color: var(--quiet);
  list-style-position: inside;
}
.filters summary:hover { color: var(--text); }
.filters[open] summary { color: var(--cyan-bright); }
.filter-group { padding: 4px 2px 9px; }
.chip-row { display: flex; flex-wrap: wrap; gap: 6px; }

/* ---------- rail / panel ---------- */

.rail { position: sticky; top: calc(var(--topbar-height) + 14px); min-width: 0; }
.panel {
  border: 1px solid var(--line); border-radius: var(--radius-md);
  background: var(--surface-2); padding: 16px 16px 18px;
  max-height: calc(100vh - var(--topbar-height) - 90px);
  overflow-y: auto;
  font-size: 0.83rem; line-height: 1.6; color: var(--muted);
}
.panel h2 { margin: 0 0 4px; color: var(--text); font-size: 1.1rem; font-weight: 720; letter-spacing: -0.02em; }
.panel h3 { margin: 16px 0 6px; color: var(--text); font-size: 0.82rem; font-weight: 700; }
.panel h4 {
  margin: 10px 0 3px; color: var(--cyan); font-family: "IBM Plex Mono", monospace;
  font-size: 0.62rem; font-weight: 600; letter-spacing: 0.12em; text-transform: uppercase;
}
.panel .meta { color: var(--quiet); font-family: "IBM Plex Mono", monospace; font-size: 0.72rem; margin: 0 0 8px; }
.panel ul { margin: 4px 0; padding-left: 18px; }
.panel li { margin: 3px 0; }
.panel .hint { color: var(--quiet); }
.panel .tags { display: flex; flex-wrap: wrap; gap: 5px; margin: 6px 0; }
.panel .tag {
  display: inline-flex; padding: 2px 8px; border: 1px solid var(--line); border-radius: 999px;
  color: var(--muted); font-size: 0.64rem; font-weight: 650; letter-spacing: 0.04em;
}
.panel .links a { font-size: 0.78rem; }
.panel button.mini {
  display: inline-flex; align-items: center; min-height: 22px; padding: 1px 9px;
  border: 1px solid rgba(92, 232, 241, 0.4); border-radius: 999px;
  color: var(--cyan-bright); background: transparent;
  font: inherit; font-size: 0.66rem; font-weight: 650; cursor: pointer;
}
.panel button.mini:hover { background: rgba(24, 89, 103, 0.5); }

.rail-strap { margin: 8px 4px 0; color: var(--quiet); font-size: 0.68rem; }

/* Collapsible panel sections */
.fold { margin: 10px 0; border: 1px solid var(--line); border-radius: var(--radius-sm); background: rgba(9, 32, 43, 0.35); }
.fold > summary {
  cursor: pointer; padding: 8px 11px; font-size: 0.76rem; font-weight: 650;
  color: var(--muted); list-style-position: inside; user-select: none;
}
.fold > summary:hover { color: var(--text); }
.fold[open] > summary { color: var(--cyan-bright); border-bottom: 1px solid var(--line); }
.fold-body { padding: 8px 12px 10px; }
.fold.nested { margin: 6px 0; background: rgba(9, 32, 43, 0.5); }
.fold.nested > summary { font-size: 0.72rem; padding: 6px 10px; }

/* ---------- dialogs ---------- */

.site-dialog {
  width: min(92vw, 640px); padding: 0; border: 1px solid var(--line-strong);
  border-radius: 12px; color: var(--text); background: var(--surface-2);
  box-shadow: 0 20px 52px rgba(0, 7, 13, 0.42);
}
.site-dialog::backdrop { background: rgba(0, 5, 9, 0.76); backdrop-filter: blur(8px); }
.dialog-shell { max-height: min(88vh, 760px); margin: 0; padding: 24px; overflow-y: auto; border-radius: inherit; }
.dialog-shell h2 {
  max-width: 520px; margin: 0 0 14px; color: var(--text);
  font-size: clamp(1.18rem, 3vw, 1.7rem); font-weight: 720;
  letter-spacing: -0.026em; line-height: 1.15;
}
.dialog-shell p { font-size: 0.83rem; line-height: 1.62; color: var(--muted); }
.dialog-shell .howto { margin: 10px 0; padding-left: 20px; font-size: 0.83rem; line-height: 1.7; color: var(--muted); }
.dialog-shell strong { color: var(--text); }
.signoff { margin-top: 16px; color: var(--text); font-weight: 650; }
.signoff span { display: block; color: var(--quiet); font-weight: 400; font-size: 0.76rem; }
.creator-card {
  margin: 14px 0; padding: 12px 14px; border: 1px solid var(--line);
  border-radius: var(--radius-sm); background: var(--surface-3);
}
.creator-card > span {
  font-family: "IBM Plex Mono", monospace; font-size: 0.6rem; letter-spacing: 0.16em;
  color: var(--cyan);
}
.creator-card p { margin: 6px 0 0; }
.fine-print {
  padding: 10px 11px; border-left: 3px solid var(--cyan); border-radius: 0 8px 8px 0;
  color: var(--quiet) !important; background: rgba(24, 89, 103, 0.14);
  font-size: 0.69rem !important; line-height: 1.48 !important;
}
.dialog-done {
  display: inline-flex; min-height: 42px; align-items: center; justify-content: center;
  margin-top: 10px; padding: 0 17px;
  border: 1px solid rgba(92, 232, 241, 0.5); border-radius: 10px;
  color: #001217; background: var(--cyan-bright);
  font: inherit; font-weight: 700; cursor: pointer;
}

/* ---------- responsive & a11y ---------- */

@media (max-width: 1080px) {
  :root { --rail-width: clamp(300px, 34vw, 380px); }
}
@media (max-width: 820px) {
  .app-shell { grid-template-columns: 1fr; }
  .rail { position: static; }
  .panel { max-height: none; }
  .topbar { flex-wrap: wrap; }
  .searchbox input { min-width: 150px; }
  .hud-hint { display: none; }
}
@media (max-width: 480px) {
  .header-button { font-size: 0.72rem; padding: 0 9px; }
  .brand h1 { font-size: 0.95rem; }
}
@media (prefers-reduced-motion: reduce) {
  * { animation-duration: 0.01ms !important; transition-duration: 0.01ms !important; }
}
@media (prefers-contrast: more) {
  :root { --line: rgba(132, 194, 214, 0.5); --muted: #b8d0da; --quiet: #9ab5c1; }
}