/* ════════════════════════════════════════════════════════════════
   MotoTriangle — application stylesheet

   Brutalist monochrome aesthetic on a near-black canvas.
   Signal red (#E8350A) is reserved for STRUCTURAL accents only:
   borders, active states, scoring callouts. It is never used
   decoratively.

   Layout strategy:
     • CSS custom properties for every colour and font token.
     • Two display families: Barlow Condensed (headings) and
       Space Mono (everything else).
     • No framework, no preprocessor — pure CSS.

   The mototriangle.html prototype is the visual contract.
   Any change here must be applied to the prototype too, or
   noted in CHANGELOG before being shipped.
   ════════════════════════════════════════════════════════════════ */


/* ──────────────────────────────────────────────────────────────
   DESIGN TOKENS — colours and font families
   Changing one variable rebadges every component that uses it.
   ────────────────────────────────────────────────────────────── */
:root {
  /* Surface ladder — five steps from blackest to UI greys. */
  --bg:      #0a0a0a;   /* page background, behind everything */
  --bg2:     #121212;   /* secondary surfaces (sidebar, cards) */
  --bg3:     #1a1a1a;   /* inputs, raised cards */
  --bg4:     #222;      /* hover state for raised cards */

  /* Border ladder — used to draw the brutalist grid. */
  --border:  #2a2a2a;
  --border2: #3a3a3a;

  /* Text ladder — primary down to "barely visible". */
  --text:    #f0f0f0;
  --muted:   #666;
  --dim:     #444;

  /* Signal red — primary brand accent. Structural use only. */
  --red:     #E8350A;
  --red2:    #ff4a1f;

  /* Status / scoring colours. */
  --good:    #22c55e;
  --warn:    #f59e0b;
  --poor:    #ef4444;

  /* Type stacks. */
  --mono:    'Space Mono', monospace;
  --cond:    'Barlow Condensed', sans-serif;
}


/* ──────────────────────────────────────────────────────────────
   RESET
   Box-sizing + zero margin/padding, kept minimal on purpose.
   ────────────────────────────────────────────────────────────── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; }

body {
  background: var(--bg);
  color: var(--text);
  font-family: var(--mono);
  font-size: 13px;     /* Base for the whole app. All rem values cascade from this. */
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;  /* Prevent horizontal scroll from the noise overlay. */
}


/* ──────────────────────────────────────────────────────────────
   NOISE TEXTURE OVERLAY
   A single SVG feTurbulence as a data-URI, painted as a fixed
   pseudo-element on top of the page. Adds film-grain warmth to
   the otherwise flat brutalist surface. Non-interactive.
   ────────────────────────────────────────────────────────────── */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='noise'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23noise)' opacity='0.04'/%3E%3C/svg%3E");
  pointer-events: none;
  z-index: 1000;
  opacity: 0.35;
}


/* ──────────────────────────────────────────────────────────────
   HEADER
   Sticky three-column grid: logo · nav · header controls.
   Border-bottom anchors it visually as a single ribbon.
   ────────────────────────────────────────────────────────────── */
header {
  border-bottom: 1px solid var(--border);
  display: grid;
  grid-template-columns: 1fr auto 1fr;
  align-items: center;
  padding: 0 2rem;
  height: 56px;
  position: sticky;
  top: 0;
  background: var(--bg);
  z-index: 100;
}

.logo {
  font-family: var(--cond);
  font-size: 1.5rem;
  font-weight: 900;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--text);
  text-decoration: none;
}
/* The triangle glyph inside the logo is the only place the red
   accent is permitted decoratively — it IS the brand mark. */
.logo em { color: var(--red); font-style: normal; }

nav {
  display: flex;
  gap: 0;
  border: 1px solid var(--border);
}
nav a {
  color: var(--muted);
  text-decoration: none;
  font-size: 0.7rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 0.4rem 1rem;
  border-right: 1px solid var(--border);
  transition: color 0.1s, background 0.1s;
}
nav a:last-child { border-right: none; }
nav a:hover, nav a.active { color: var(--text); background: var(--bg3); }
nav a.active { color: var(--red); }

.header-right {
  display: flex;
  justify-content: flex-end;
  align-items: center;
  gap: 0.75rem;
}

/* MM / IN unit toggle — paired buttons share a single border. */
.unit-toggle {
  display: flex;
  border: 1px solid var(--border);
  font-size: 0.65rem;
}
.unit-toggle button {
  background: none;
  border: none;
  color: var(--muted);
  cursor: pointer;
  font-family: var(--mono);
  font-size: 0.65rem;
  letter-spacing: 0.1em;
  padding: 0.3rem 0.6rem;
  text-transform: uppercase;
  transition: all 0.1s;
}
.unit-toggle button.active { background: var(--red); color: #fff; }

/* Live bike-count chip in the header right-side. */
.db-count {
  font-size: 0.65rem;
  color: var(--muted);
  letter-spacing: 0.06em;
}
.db-count span { color: var(--red); font-weight: 700; }


/* ──────────────────────────────────────────────────────────────
   HERO — home page
   Two-column split. Left = copy + CTAs + stats; right = the
   ergonomic-triangle SVG diagram (rendered inline in the HTML).
   ────────────────────────────────────────────────────────────── */
.hero {
  display: grid;
  grid-template-columns: 1fr 1fr;
  min-height: calc(100vh - 56px);
  border-bottom: 1px solid var(--border);
}

.hero-left {
  padding: 4rem 3rem;
  border-right: 1px solid var(--border);
  display: flex;
  flex-direction: column;
  justify-content: center;
  position: relative;
  overflow: hidden;
}

/* "Tag" line above the hero title — small caps + leading dash. */
.hero-tag {
  font-size: 0.65rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--red);
  margin-bottom: 1.5rem;
  display: flex;
  align-items: center;
  gap: 0.75rem;
}
.hero-tag::before {
  content: '';
  display: block;
  width: 2rem;
  height: 1px;
  background: var(--red);
}

.hero-title {
  font-family: var(--cond);
  font-size: clamp(3.5rem, 7vw, 6rem);
  font-weight: 900;
  line-height: 0.9;
  letter-spacing: -0.01em;
  text-transform: uppercase;
  margin-bottom: 2rem;
}
.hero-title .accent { color: var(--red); display: block; }

.hero-desc {
  color: var(--muted);
  font-size: 0.8rem;
  max-width: 420px;
  line-height: 1.8;
  margin-bottom: 2.5rem;
}

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

/* Button system. Two variants only — primary (red) and ghost. */
.btn {
  font-family: var(--mono);
  font-size: 0.7rem;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  padding: 0.75rem 1.5rem;
  border: none;
  cursor: pointer;
  transition: all 0.15s;
  text-decoration: none;
  display: inline-block;
}
.btn-primary { background: var(--red); color: #fff; }
.btn-primary:hover { background: var(--red2); }
.btn-ghost { background: none; border: 1px solid var(--border2); color: var(--muted); }
.btn-ghost:hover { border-color: var(--text); color: var(--text); }

/* Stats strip at the bottom of the hero left column. */
.hero-stats {
  display: flex;
  gap: 2rem;
  margin-top: 3rem;
  padding-top: 2rem;
  border-top: 1px solid var(--border);
}
.stat-num {
  font-family: var(--cond);
  font-size: 2rem;
  font-weight: 900;
  color: var(--text);
  line-height: 1;
}
.stat-num span { color: var(--red); }
.stat-label {
  font-size: 0.65rem;
  color: var(--muted);
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-top: 0.2rem;
}

/* Right hero pane — wraps the triangle SVG on a slightly lighter bg. */
.hero-right {
  display: flex;
  align-items: center;
  justify-content: center;
  background: var(--bg2);
  position: relative;
  padding: 2rem;
}

.triangle-diagram {
  width: 100%;
  max-width: 500px;
}


/* ──────────────────────────────────────────────────────────────
   SECTION SWITCHING
   The site is a single page with several <section> blocks; only
   one carries .active at a time. JS swaps the class on nav clicks.
   ────────────────────────────────────────────────────────────── */
section { display: none; }
section.active { display: block; }


/* ──────────────────────────────────────────────────────────────
   FIT-CHECK PAGE
   380px sidebar (rider inputs + bike selector) | flexible main
   pane (results panel). On small screens the sidebar stacks
   above the main pane.
   ────────────────────────────────────────────────────────────── */
.calc-layout {
  display: grid;
  grid-template-columns: 380px 1fr;
  min-height: calc(100vh - 56px);
}

.calc-sidebar {
  border-right: 1px solid var(--border);
  padding: 2rem;
  background: var(--bg2);
  overflow-y: auto;
}

.calc-main {
  padding: 2rem;
  overflow-y: auto;
}

/* Reusable little caps-and-rule section header. */
.section-label {
  font-size: 0.6rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--red);
  margin-bottom: 1.25rem;
  display: flex;
  align-items: center;
  gap: 0.5rem;
}
.section-label::after {
  content: '';
  flex: 1;
  height: 1px;
  background: var(--border);
}

/* Form field stack. */
.field-group { margin-bottom: 1.25rem; }

label {
  display: block;
  font-size: 0.65rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 0.35rem;
}

input[type="number"], input[type="text"], select {
  width: 100%;
  background: var(--bg3);
  border: 1px solid var(--border);
  color: var(--text);
  font-family: var(--mono);
  font-size: 0.875rem;
  padding: 0.6rem 0.75rem;
  outline: none;
  transition: border-color 0.15s;
  -moz-appearance: textfield;
}
input[type="number"]::-webkit-outer-spin-button,
input[type="number"]::-webkit-inner-spin-button { -webkit-appearance: none; }
input[type="number"]:focus,
input[type="text"]:focus,
select:focus { border-color: var(--red); }

select option { background: var(--bg3); }

/* Unit suffix sitting inside a number input ("cm" / "in"). */
.input-unit { position: relative; }
.input-unit input { padding-right: 3rem; }
.input-unit .unit {
  position: absolute;
  right: 0.75rem;
  top: 50%;
  transform: translateY(-50%);
  font-size: 0.65rem;
  color: var(--dim);
  letter-spacing: 0.06em;
  pointer-events: none;
}

.field-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 0.75rem; }

/* The big primary calculate button at the bottom of the sidebar. */
.calc-btn {
  width: 100%;
  background: var(--red);
  border: none;
  color: #fff;
  font-family: var(--mono);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.15em;
  text-transform: uppercase;
  padding: 0.875rem;
  cursor: pointer;
  transition: background 0.15s;
  margin-top: 1.5rem;
}
.calc-btn:hover { background: var(--red2); }


/* ──────────────────────────────────────────────────────────────
   BIKE SEARCH (sidebar)
   Search input with a glyph icon overlay + filter pills + the
   scrollable list of bike cards.
   ────────────────────────────────────────────────────────────── */
.bike-search-wrap { position: relative; margin-bottom: 1.5rem; }
.bike-search-wrap input { padding-left: 2.5rem; width: 100%; }
.search-icon {
  position: absolute;
  left: 0.75rem;
  top: 50%;
  transform: translateY(-50%);
  color: var(--muted);
  font-size: 0.75rem;
  pointer-events: none;
}

.bike-list {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
  max-height: 320px;
  overflow-y: auto;
}

.bike-card {
  border: 1px solid var(--border);
  background: var(--bg3);
  padding: 0.875rem 1rem;
  cursor: pointer;
  transition: border-color 0.1s, background 0.1s;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
}
.bike-card:hover    { border-color: var(--border2); background: var(--bg4); }
.bike-card.selected { border-color: var(--red); }

.bike-card-left { flex: 1; min-width: 0; }
.bike-brand {
  font-size: 0.6rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
}
.bike-model {
  font-family: var(--cond);
  font-size: 1.1rem;
  font-weight: 700;
  letter-spacing: 0.02em;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}
.bike-year { font-size: 0.7rem; color: var(--dim); }

.bike-seat { text-align: right; flex-shrink: 0; }
.bike-seat-num {
  font-family: var(--cond);
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--text);
  line-height: 1;
}
.bike-seat-label { font-size: 0.6rem; color: var(--muted); letter-spacing: 0.06em; }

/* Small category badge used in cards and the DB table. */
.cat-badge {
  display: inline-block;
  font-size: 0.55rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 0.15rem 0.4rem;
  border: 1px solid var(--border);
  color: var(--dim);
  margin-top: 0.25rem;
}


/* ──────────────────────────────────────────────────────────────
   FIT RESULTS
   Placeholder shown until the user clicks calculate, then the
   .fit-result panel appears with score + 4 dimension cards.
   ────────────────────────────────────────────────────────────── */
.results-placeholder {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 400px;
  color: var(--muted);
  border: 1px dashed var(--border);
  text-align: center;
  gap: 1rem;
}
.results-placeholder .big {
  font-family: var(--cond);
  font-size: 3rem;
  font-weight: 900;
  color: var(--border2);
}

.fit-result         { display: none; }
.fit-result.visible { display: block; }

.result-header {
  display: grid;
  grid-template-columns: 1fr auto;
  align-items: start;
  gap: 2rem;
  margin-bottom: 2rem;
  padding-bottom: 2rem;
  border-bottom: 1px solid var(--border);
}

.result-bike-name {
  font-family: var(--cond);
  font-size: 2.5rem;
  font-weight: 900;
  line-height: 1;
  text-transform: uppercase;
  letter-spacing: 0.02em;
}
.result-bike-sub { font-size: 0.7rem; color: var(--muted); letter-spacing: 0.08em; margin-top: 0.5rem; }

/* Boxed numeric score. Colour swapped by JS based on verdict. */
.score-block {
  text-align: center;
  border: 1px solid var(--border);
  padding: 1.25rem 2rem;
  min-width: 120px;
}
.score-num {
  font-family: var(--cond);
  font-size: 3.5rem;
  font-weight: 900;
  line-height: 1;
}
.score-num.good { color: var(--good); }
.score-num.warn { color: var(--warn); }
.score-num.poor { color: var(--poor); }
.score-label {
  font-size: 0.6rem;
  color: var(--muted);
  letter-spacing: 0.1em;
  text-transform: uppercase;
  margin-top: 0.25rem;
}
.score-verdict {
  font-size: 0.65rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  margin-top: 0.5rem;
  font-weight: 700;
}
.score-verdict.good { color: var(--good); }
.score-verdict.warn { color: var(--warn); }
.score-verdict.poor { color: var(--poor); }

/* 2x2 grid of dimension cards. The single-pixel gap is the
   .dimensions-grid background showing through. */
.dimensions-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: var(--border);
  border: 1px solid var(--border);
  margin-bottom: 1.5rem;
}

.dim-card {
  background: var(--bg2);
  padding: 1.25rem;
  position: relative;
  overflow: hidden;
}
/* Left-edge status stripe — 3px coloured bar driven by .status. */
.dim-card::before {
  content: '';
  position: absolute;
  left: 0; top: 0; bottom: 0;
  width: 3px;
}
.dim-card.good::before    { background: var(--good); }
.dim-card.warn::before    { background: var(--warn); }
.dim-card.poor::before    { background: var(--poor); }
.dim-card.unknown::before { background: var(--border2); }

.dim-label {
  font-size: 0.6rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--muted);
  margin-bottom: 0.5rem;
}
.dim-value {
  font-family: var(--cond);
  font-size: 2rem;
  font-weight: 900;
  line-height: 1;
  margin-bottom: 0.4rem;
}
.dim-value.good    { color: var(--good); }
.dim-value.warn    { color: var(--warn); }
.dim-value.poor    { color: var(--poor); }
.dim-value.unknown { color: var(--dim); }
.dim-msg { font-size: 0.7rem; color: var(--muted); line-height: 1.5; }

.triangle-result-svg { width: 100%; margin-bottom: 1.5rem; }

/* "Partial data" warning banner inside the result panel. */
.data-warn {
  border: 1px solid var(--border);
  border-left: 3px solid var(--warn);
  padding: 0.75rem 1rem;
  font-size: 0.75rem;
  color: var(--muted);
  margin-bottom: 1.5rem;
}
.data-warn strong { color: var(--warn); }


/* ──────────────────────────────────────────────────────────────
   BIKE DATABASE PAGE
   ────────────────────────────────────────────────────────────── */
.db-layout { padding: 2rem; }

.db-toolbar {
  display: flex;
  gap: 1rem;
  margin-bottom: 1.5rem;
  align-items: center;
  flex-wrap: wrap;
}

.db-toolbar input {
  flex: 1;
  min-width: 220px;
  background: var(--bg2);
  border: 1px solid var(--border);
  color: var(--text);
  font-family: var(--mono);
  font-size: 0.8rem;
  padding: 0.6rem 0.75rem;
  outline: none;
}
.db-toolbar input:focus { border-color: var(--red); }

/* Pill-style category filters. */
.filter-pills { display: flex; gap: 0.35rem; flex-wrap: wrap; }
.pill {
  font-family: var(--mono);
  font-size: 0.6rem;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  padding: 0.3rem 0.6rem;
  border: 1px solid var(--border);
  background: none;
  color: var(--muted);
  cursor: pointer;
  transition: all 0.1s;
}
.pill:hover { border-color: var(--border2); color: var(--text); }
.pill.active { background: var(--red); border-color: var(--red); color: #fff; }

.db-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.78rem;
}
.db-table th {
  font-size: 0.6rem;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--muted);
  text-align: left;
  padding: 0.5rem 0.75rem;
  border-bottom: 1px solid var(--border);
  white-space: nowrap;
}
.db-table td {
  padding: 0.75rem;
  border-bottom: 1px solid var(--border);
  vertical-align: middle;
}
.db-table tr:hover td { background: var(--bg2); }
.db-table .brand-cell { color: var(--muted); font-size: 0.7rem; }
.db-table .model-cell { font-family: var(--cond); font-size: 1rem; font-weight: 700; }
.db-table .num-cell   { font-family: var(--cond); font-size: 1rem; font-weight: 600; }
.db-table .missing    { color: var(--border2); }

/* Five-segment completeness indicator (0–5 filled fields). */
.completeness-bar {
  width: 60px;
  height: 4px;
  background: var(--border);
  position: relative;
}
.completeness-fill {
  position: absolute;
  left: 0; top: 0; bottom: 0;
  background: var(--red);
  transition: width 0.3s;
}
.completeness-fill.full    { background: var(--good); }
.completeness-fill.partial { background: var(--warn); }

/* Pagination bar under the table. */
.db-pagination {
  display: flex;
  gap: 0.4rem;
  align-items: center;
  justify-content: center;
  margin-top: 1.5rem;
  flex-wrap: wrap;
}
.db-pagination .page-btn {
  font-family: var(--mono);
  font-size: 0.65rem;
  padding: 0.35rem 0.7rem;
  border: 1px solid var(--border);
  background: none;
  color: var(--muted);
  cursor: pointer;
  transition: all 0.1s;
}
.db-pagination .page-btn:hover    { border-color: var(--border2); color: var(--text); }
.db-pagination .page-btn.active   { background: var(--red); border-color: var(--red); color: #fff; }
.db-pagination .page-btn[disabled]{ opacity: 0.3; cursor: not-allowed; }
.db-pagination .page-info {
  font-size: 0.65rem;
  color: var(--muted);
  letter-spacing: 0.06em;
  padding: 0 0.5rem;
}


/* ──────────────────────────────────────────────────────────────
   CHANGELOG PAGE
   Vertical timeline of entries, each pinned to a date column.
   ────────────────────────────────────────────────────────────── */
.changelog-wrap {
  max-width: 880px;
  margin: 0 auto;
  padding: 3rem 2rem;
}
.changelog-title {
  font-family: var(--cond);
  font-size: 3rem;
  font-weight: 900;
  text-transform: uppercase;
  line-height: 1;
  margin-bottom: 0.5rem;
}
.changelog-intro {
  color: var(--muted);
  font-size: 0.78rem;
  margin-bottom: 2.5rem;
}
.changelog-entry {
  display: grid;
  grid-template-columns: 140px 1fr;
  gap: 1.5rem;
  border: 1px solid var(--border);
  border-bottom: none;
  padding: 1.25rem;
}
.changelog-entry:last-of-type { border-bottom: 1px solid var(--border); }
.changelog-date {
  font-size: 0.7rem;
  color: var(--red);
  letter-spacing: 0.12em;
  text-transform: uppercase;
}
.changelog-tag {
  display: inline-block;
  font-size: 0.55rem;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  padding: 0.15rem 0.4rem;
  border: 1px solid var(--border2);
  color: var(--muted);
  margin-bottom: 0.5rem;
}
.changelog-headline {
  font-family: var(--cond);
  font-size: 1.4rem;
  font-weight: 700;
  text-transform: uppercase;
  margin-bottom: 0.25rem;
  letter-spacing: 0.02em;
}
.changelog-body { font-size: 0.78rem; color: var(--muted); line-height: 1.7; }
.changelog-body ul { margin-left: 1.25rem; }


/* ──────────────────────────────────────────────────────────────
   FOOTER
   Three-segment row: left credit, middle data licence, right
   provenance line (the small grey credit to johlem.net).
   ────────────────────────────────────────────────────────────── */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 1.5rem 2rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 1rem;
  color: var(--muted);
  font-size: 0.65rem;
  letter-spacing: 0.06em;
  flex-wrap: wrap;
}
.site-footer a { color: inherit; }
.site-footer .footer-mid { color: var(--muted); }
.site-footer .footer-credit { font-size: 0.58rem; color: #444; }
.site-footer .footer-credit a { color: #444; text-decoration: underline; }


/* ──────────────────────────────────────────────────────────────
   SCROLLBAR
   Thin minimal scrollbar that fits the brutalist aesthetic.
   ────────────────────────────────────────────────────────────── */
::-webkit-scrollbar { width: 4px; height: 4px; }
::-webkit-scrollbar-track { background: var(--bg); }
::-webkit-scrollbar-thumb { background: var(--border2); }
::-webkit-scrollbar-thumb:hover { background: var(--dim); }


/* ──────────────────────────────────────────────────────────────
   ANIMATIONS
   Used only for subtle fade-ins on dynamic content.
   ────────────────────────────────────────────────────────────── */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(8px); }
  to   { opacity: 1; transform: translateY(0); }
}
.fade-in { animation: fadeIn 0.3s ease forwards; }

@keyframes barGrow {
  from { width: 0; }
  to   { width: var(--w); }
}


/* ──────────────────────────────────────────────────────────────
   RESPONSIVE
   ≤900px: hero, calc layout, table cells stack instead of grid.
   Mobile users still see all data, just in a single column.
   ────────────────────────────────────────────────────────────── */
@media (max-width: 900px) {
  header { grid-template-columns: auto 1fr auto; padding: 0 1rem; }
  nav { display: none; }                            /* nav collapses on tiny screens */
  .hero { grid-template-columns: 1fr; }
  .hero-left { padding: 2rem 1.25rem; border-right: none; border-bottom: 1px solid var(--border); }
  .hero-right { padding: 1rem; }

  .calc-layout { grid-template-columns: 1fr; }
  .calc-sidebar { border-right: none; border-bottom: 1px solid var(--border); }

  .db-layout { padding: 1rem; }
  .db-table { font-size: 0.7rem; }
  .db-table th, .db-table td { padding: 0.5rem 0.4rem; }

  .dimensions-grid { grid-template-columns: 1fr; }
  .result-header { grid-template-columns: 1fr; }

  .changelog-entry { grid-template-columns: 1fr; gap: 0.5rem; padding: 1rem; }
}