/* Bitcoin Glossary — a multilingual dictionary
   Palette and type are tuned to read like printed reference material:
   warm paper, a bronze accent, serif headwords, sans-serif definitions. */

:root {
  --paper:        #f6f1e8;
  --surface:      #fffdf8;
  --surface-alt:  #fbf6ec;
  --ink:          #211c15;
  --ink-2:        #4d443a;
  --muted:        #8a7e6e;
  --rule:         #e4dbca;
  --rule-strong:  #cdc0a9;
  --accent:       #96522a;
  --accent-ink:   #ffffff;
  --accent-soft:  #f0e3d4;
  --mark:         #f7dca9;
  --shadow:       0 1px 2px rgba(59, 44, 24, .06), 0 8px 24px -12px rgba(59, 44, 24, .18);

  --serif: "Iowan Old Style", "Palatino Linotype", Palatino, "Book Antiqua", Georgia, "Times New Roman", serif;
  --sans: ui-sans-serif, system-ui, -apple-system, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  --mono: ui-monospace, SFMono-Regular, Menlo, Consolas, "Liberation Mono", monospace;

  --cols: 2;
  --toolbar-h: 0px;
  --gutter: clamp(1rem, 4vw, 2.5rem);
}

[data-theme="dark"] {
  --paper:        #14110d;
  --surface:      #1c1813;
  --surface-alt:  #221d16;
  --ink:          #efe8da;
  --ink-2:        #cabfae;
  --muted:        #978975;
  --rule:         #2e2720;
  --rule-strong:  #473c2f;
  --accent:       #dd9c60;
  --accent-ink:   #1c1813;
  --accent-soft:  #322418;
  --mark:         #5d451f;
  --shadow:       0 1px 2px rgba(0, 0, 0, .4), 0 8px 24px -12px rgba(0, 0, 0, .7);
}

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

/* Author `display` declarations outrank the UA sheet's [hidden] rule, so
   .empty (flex) and .colhead (grid) would stay visible when hidden is set. */
[hidden] { display: none !important; }

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

body {
  margin: 0;
  background: var(--paper);
  color: var(--ink);
  font-family: var(--sans);
  font-size: 16px;
  line-height: 1.55;
  -webkit-font-smoothing: antialiased;
}

h1, h2, h3 { margin: 0; font-weight: 600; letter-spacing: -0.01em; }

button, input, select { font: inherit; color: inherit; }

:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
  border-radius: 4px;
}

.sr-only {
  position: absolute;
  width: 1px; height: 1px;
  margin: -1px; padding: 0;
  overflow: hidden;
  clip-path: inset(50%);
  white-space: nowrap;
}

.skip-link {
  position: absolute;
  left: -9999px;
  top: 0;
  z-index: 60;
  padding: .6rem 1rem;
  background: var(--accent);
  color: var(--accent-ink);
  text-decoration: none;
  border-radius: 0 0 8px 0;
}
.skip-link:focus { left: 0; }

/* ---------------------------------------------------------------- masthead */

.masthead {
  border-bottom: 1px solid var(--rule);
  background:
    linear-gradient(var(--surface-alt), var(--surface-alt)),
    var(--paper);
}

.masthead__inner {
  max-width: 1500px;
  margin: 0 auto;
  padding: clamp(1.25rem, 3vw, 2.25rem) var(--gutter);
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: 1.5rem;
  flex-wrap: wrap;
}

.brand { display: flex; align-items: center; gap: 1rem; }

.brand__mark {
  display: grid;
  place-items: center;
  width: 3rem;
  height: 3rem;
  flex: none;
  border-radius: 50%;
  border: 1.5px solid var(--accent);
  color: var(--accent);
  font-family: var(--serif);
  font-size: 1.4rem;
  line-height: 1;
  background: var(--surface);
  box-shadow: inset 0 0 0 3px var(--surface), inset 0 0 0 4px var(--accent-soft);
}

.brand h1 {
  font-family: var(--serif);
  font-size: clamp(1.5rem, 3.2vw, 2.1rem);
  line-height: 1.1;
}

.brand p {
  margin: .3rem 0 0;
  color: var(--muted);
  font-size: .9rem;
  max-width: 46ch;
}

.masthead__side { display: flex; align-items: center; gap: 1rem; }

.tally {
  margin: 0;
  color: var(--muted);
  font-size: .8rem;
  font-variant-numeric: tabular-nums;
  letter-spacing: .02em;
  text-align: right;
}
.tally b { color: var(--ink); font-weight: 600; }

.icon-btn {
  display: grid;
  place-items: center;
  width: 2.4rem;
  height: 2.4rem;
  flex: none;
  padding: 0;
  border: 1px solid var(--rule-strong);
  border-radius: 50%;
  background: var(--surface);
  color: var(--ink-2);
  cursor: pointer;
  transition: color .15s, border-color .15s;
}
.icon-btn:hover { color: var(--accent); border-color: var(--accent); }
.icon-btn svg {
  width: 1.05rem; height: 1.05rem;
  fill: none; stroke: currentColor; stroke-width: 1.7;
  stroke-linecap: round; stroke-linejoin: round;
}
.icon-moon { display: none; }
[data-theme="dark"] .icon-sun { display: none; }
[data-theme="dark"] .icon-moon { display: block; }

/* Sidebar toggle: the panel icon loses its category column when collapsed. */
#sidebar-toggle { width: 2.05rem; height: 2.05rem; }
#sidebar-toggle svg { width: 1.1rem; height: 1.1rem; }
#sidebar-toggle[aria-expanded="true"] { color: var(--accent); border-color: var(--accent); }
[data-sidebar="hidden"] .panel-divider,
[data-sidebar="hidden"] .panel-lines { display: none; }

/* ----------------------------------------------------------------- toolbar */

.toolbar {
  position: sticky;
  top: 0;
  z-index: 30;
  background: color-mix(in srgb, var(--paper) 92%, transparent);
  backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--rule);
}

.toolbar__inner {
  max-width: 1500px;
  margin: 0 auto;
  padding: .75rem var(--gutter);
  display: flex;
  align-items: center;
  gap: 1rem 1.5rem;
  flex-wrap: wrap;
}

.search {
  position: relative;
  flex: 1 1 20rem;
  min-width: 15rem;
  display: flex;
  align-items: center;
}
.search__icon {
  position: absolute;
  left: .8rem;
  width: 1.05rem; height: 1.05rem;
  fill: none; stroke: var(--muted); stroke-width: 1.8; stroke-linecap: round;
  pointer-events: none;
}
.search input {
  width: 100%;
  padding: .6rem 2.6rem;
  border: 1px solid var(--rule-strong);
  border-radius: 999px;
  background: var(--surface);
  color: var(--ink);
}
.search input::placeholder { color: var(--muted); }
.search input:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
.search input::-webkit-search-cancel-button { cursor: pointer; }
.search__hint {
  position: absolute;
  right: .75rem;
  font-family: var(--mono);
  font-size: .7rem;
  color: var(--muted);
  border: 1px solid var(--rule-strong);
  border-radius: 4px;
  padding: 0 .35rem;
  pointer-events: none;
}
.search input:focus ~ .search__hint,
.search input:not(:placeholder-shown) ~ .search__hint { opacity: 0; }

.langs { display: flex; align-items: center; gap: .6rem; }
.langs__label, .select__label {
  font-size: .68rem;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--muted);
  white-space: nowrap;
}
.langs__chips { display: flex; gap: .4rem; flex-wrap: wrap; }

.chip {
  display: inline-flex;
  align-items: baseline;
  gap: .4rem;
  padding: .38rem .8rem;
  border: 1px solid var(--rule-strong);
  border-radius: 999px;
  background: var(--surface);
  color: var(--ink-2);
  cursor: pointer;
  white-space: nowrap;
  font-size: .85rem;
  transition: background .15s, color .15s, border-color .15s;
}
.chip:hover { border-color: var(--accent); }
.chip__code {
  font-family: var(--mono);
  font-size: .68rem;
  letter-spacing: .04em;
  color: var(--muted);
  text-transform: uppercase;
}
.chip[aria-pressed="true"] {
  background: var(--accent);
  border-color: var(--accent);
  color: var(--accent-ink);
}
.chip[aria-pressed="true"] .chip__code { color: inherit; opacity: .7; }

.select { display: flex; align-items: center; gap: .6rem; }
.select select {
  padding: .4rem 2rem .4rem .7rem;
  border: 1px solid var(--rule-strong);
  border-radius: 8px;
  background: var(--surface);
  cursor: pointer;
  appearance: none;
  background-image: linear-gradient(45deg, transparent 50%, currentColor 50%),
                    linear-gradient(135deg, currentColor 50%, transparent 50%);
  background-position: calc(100% - 1.05rem) 55%, calc(100% - .75rem) 55%;
  background-size: .3rem .3rem, .3rem .3rem;
  background-repeat: no-repeat;
  font-size: .85rem;
}

/* -------------------------------------------------------------- page shell */

.page {
  max-width: 1500px;
  margin: 0 auto;
  padding: 0 var(--gutter) 4rem;
  display: grid;
  grid-template-columns: 13.5rem minmax(0, 1fr);
  gap: 0 2.5rem;
  align-items: start;
}

/* Collapsed by choice — the toolbar's category select still covers filtering. */
[data-sidebar="hidden"] .page { grid-template-columns: minmax(0, 1fr); }
[data-sidebar="hidden"] .sidebar { display: none; }

.sidebar {
  position: sticky;
  top: calc(var(--toolbar-h) + 1.5rem);
  padding: 1.75rem 0;
  max-height: calc(100vh - var(--toolbar-h) - 3rem);
  overflow-y: auto;
}

.sidebar__title {
  margin: 0 0 .75rem;
  font-size: .68rem;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--muted);
}

.sidebar__list { list-style: none; margin: 0; padding: 0; }

.sidebar__list button {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: .5rem;
  width: 100%;
  padding: .3rem .55rem;
  border: 0;
  border-radius: 6px;
  background: none;
  text-align: left;
  color: var(--ink-2);
  font-size: .85rem;
  cursor: pointer;
  transition: background .12s, color .12s;
}
.sidebar__list button:hover { background: var(--surface); color: var(--ink); }
.sidebar__list button[aria-current="true"] {
  background: var(--accent-soft);
  color: var(--accent);
  font-weight: 600;
}
.sidebar__count {
  font-family: var(--mono);
  font-size: .7rem;
  color: var(--muted);
  font-variant-numeric: tabular-nums;
}
.sidebar__list button[aria-current="true"] .sidebar__count { color: inherit; }

.content { padding: 1.75rem 0; min-width: 0; }

/* --------------------------------------------------------- column headings */

.colhead {
  position: sticky;
  top: var(--toolbar-h);
  z-index: 20;
  display: grid;
  grid-template-columns: repeat(var(--cols), minmax(0, 1fr));
  gap: 0 2rem;
  padding: .7rem 0 .55rem;
  margin-bottom: -1px;
  background: color-mix(in srgb, var(--paper) 94%, transparent);
  backdrop-filter: blur(8px);
  border-bottom: 2px solid var(--rule-strong);
}

.colhead__cell { min-width: 0; padding-left: .1rem; }
.colhead__name {
  font-family: var(--serif);
  font-size: 1.02rem;
  line-height: 1.2;
}
.colhead__meta {
  font-size: .68rem;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--muted);
}

/* --------------------------------------------------------------- the pages */

.section { margin: 0 0 2.75rem; }

.section__head {
  display: flex;
  align-items: baseline;
  gap: .9rem;
  padding: 1.6rem 0 .6rem;
}
.section__head h2 {
  font-family: var(--serif);
  font-size: 1.15rem;
  letter-spacing: .01em;
  white-space: nowrap;
}
.section__rule { flex: 1; height: 1px; background: var(--rule-strong); }
.section__count {
  font-family: var(--mono);
  font-size: .7rem;
  color: var(--muted);
  white-space: nowrap;
}

.entry {
  position: relative;
  display: grid;
  grid-template-columns: repeat(var(--cols), minmax(0, 1fr));
  gap: 0 2rem;
  align-items: start;
  padding: .95rem 0;
  border-bottom: 1px solid var(--rule);
  scroll-margin-top: calc(var(--toolbar-h) + 5rem);
}
/* The highlight bleeds into the page gutters via a negative-z pseudo-element.
   A spread box-shadow would do the same job but paints over the text of the
   row above it, since in-flow siblings paint in tree order. */
.entry::before {
  content: "";
  position: absolute;
  inset: 0 calc(var(--gutter) * -1);
  z-index: -1;
  border-radius: 5px;
  pointer-events: none;
}
.entry:hover::before { background: var(--surface); }
.entry.is-linked::before { background: var(--accent-soft); }

.entry__anchor {
  position: absolute;
  left: -1.35rem;
  top: 1.15rem;
  color: var(--muted);
  text-decoration: none;
  font-size: .85rem;
  opacity: 0;
  transition: opacity .12s, color .12s;
}
.entry:hover .entry__anchor { opacity: 1; }
.entry__anchor:hover, .entry__anchor:focus-visible { color: var(--accent); opacity: 1; }

.cell { min-width: 0; }

.cell__lang {
  display: none;
  font-size: .64rem;
  letter-spacing: .12em;
  text-transform: uppercase;
  color: var(--accent);
  margin-bottom: .2rem;
}

.cell__term {
  font-family: var(--serif);
  font-size: 1.14rem;
  line-height: 1.3;
  color: var(--ink);
  overflow-wrap: break-word;
}
.cell--empty .cell__term { color: var(--muted); font-style: italic; }

.cell__explanation {
  margin: .3rem 0 0;
  color: var(--ink-2);
  font-size: .9rem;
  line-height: 1.55;
  overflow-wrap: break-word;
}

.cell__note {
  margin: .45rem 0 0;
  padding-left: .7rem;
  border-left: 2px solid var(--accent-soft);
  color: var(--muted);
  font-size: .8rem;
  line-height: 1.5;
}
.cell__note b {
  font-weight: 600;
  font-size: .64rem;
  letter-spacing: .1em;
  text-transform: uppercase;
  color: var(--accent);
  margin-right: .35rem;
}

mark {
  background: var(--mark);
  color: inherit;
  border-radius: 2px;
  padding: 0 .06em;
}

/* ------------------------------------------------------------ misc states */

.loading, .empty {
  padding: 3.5rem 0;
  text-align: center;
  color: var(--muted);
}
.empty { display: flex; flex-direction: column; align-items: center; gap: .4rem; }
.empty strong { color: var(--ink); font-family: var(--serif); font-size: 1.15rem; font-weight: 600; }

.btn {
  margin-top: .8rem;
  padding: .45rem 1.1rem;
  border: 1px solid var(--accent);
  border-radius: 999px;
  background: none;
  color: var(--accent);
  cursor: pointer;
  font-size: .85rem;
}
.btn:hover { background: var(--accent); color: var(--accent-ink); }

.error {
  max-width: 44rem;
  margin: 3rem auto;
  padding: 1.5rem;
  border: 1px solid var(--rule-strong);
  border-radius: 10px;
  background: var(--surface);
  box-shadow: var(--shadow);
}
.error h2 { font-family: var(--serif); font-size: 1.2rem; margin-bottom: .5rem; }
.error p { color: var(--ink-2); font-size: .9rem; }
.error pre {
  margin: .8rem 0 0;
  padding: .8rem 1rem;
  overflow-x: auto;
  border-radius: 8px;
  background: var(--surface-alt);
  border: 1px solid var(--rule);
  font-family: var(--mono);
  font-size: .8rem;
}

.colophon {
  border-top: 1px solid var(--rule);
  background: var(--surface-alt);
  padding: 2rem var(--gutter);
  color: var(--muted);
  font-size: .82rem;
}
.colophon p { max-width: 1500px; margin: 0 auto; }
.colophon__meta { margin-top: .4rem; font-family: var(--mono); font-size: .72rem; }

/* --------------------------------------------------------------- responsive */

@media (max-width: 1080px) {
  .page { grid-template-columns: minmax(0, 1fr); }
  .sidebar { display: none; }
  #sidebar-toggle { display: none; }  /* nothing to collapse at this width */
}

@media (max-width: 760px) {
  .masthead__inner { align-items: center; }
  .tally { display: none; }

  /* Keep the sticky bar shallow on small screens: search on its own line,
     languages and category sharing the next one. */
  .toolbar__inner { padding: .55rem var(--gutter); gap: .5rem .6rem; }
  .search { flex: 1 1 100%; }
  .langs { flex: 0 1 auto; }
  .langs__label, .select__label { display: none; }
  .select { flex: 1 1 8.5rem; }
  .select select { width: 100%; padding-block: .32rem; }
  .chip { padding: .32rem .65rem; }

  /* Stacked view: one language per block, each labelled, so a row still reads
     as a single entry even without side-by-side columns. */
  .colhead { display: none; }
  .entry {
    grid-template-columns: minmax(0, 1fr);
    gap: .9rem;
    padding: 1.1rem 0;
    border-bottom-color: var(--rule-strong);
  }
  .entry::before { inset: 0; }
  .entry__anchor { display: none; }
  .cell + .cell {
    border-top: 1px dotted var(--rule);
    padding-top: .9rem;
  }
  .cell__lang { display: block; }
}

@media (prefers-reduced-motion: reduce) {
  * { transition: none !important; animation: none !important; }
}

@media print {
  .toolbar, .sidebar, .icon-btn, .entry__anchor, .colophon { display: none; }
  body { background: #fff; }
  .entry { break-inside: avoid; }
  .page { display: block; }
}