/* ==========================================================================
   JF Filtr — layout and components.
   No raw colour values live here; everything resolves through tokens.css.
   ========================================================================== */

*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

html { scroll-behavior: smooth; scroll-padding-top: 5.5rem; }

body {
  background: var(--bg);
  color: var(--text-body);
  font-family: var(--font-body);
  font-size: var(--fs-base);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  text-rendering: optimizeLegibility;
  overflow-x: hidden;
}

h1, h2, h3, h4 {
  font-family: var(--font-display);
  font-weight: 600;
  line-height: 1.06;
  letter-spacing: -0.03em;
  color: var(--text-strong);
  text-wrap: balance;
}

p { text-wrap: pretty; }
a { color: inherit; }
img, svg, video { display: block; max-width: 100%; }
button, input, select, textarea { font: inherit; color: inherit; }

.mono {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  letter-spacing: 0.02em;
}
.num { font-variant-numeric: tabular-nums; }

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

::selection { background: var(--accent); color: var(--accent-on); }

/* ---------- Grain ------------------------------------------------------- */
/* Fixed film over the whole page. Breaks the sterility of flat vector fills. */

.grain {
  position: fixed;
  inset: 0;
  z-index: var(--z-grain);
  pointer-events: none;
  opacity: 0.03;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='160' height='160'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='3' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='160' height='160' filter='url(%23n)'/%3E%3C/svg%3E");
}

/* ---------- Scroll progress ---------------------------------------------- */
/* Scroll-linked, so it stays alive under reduced motion — it indicates where
   the visitor is, it does not move on its own. */

.scroll-progress {
  position: fixed;
  inset: 0 0 auto 0;
  height: 2px;
  z-index: var(--z-overlay);
  pointer-events: none;
}
.scroll-progress i {
  display: block;
  height: 100%;
  background: linear-gradient(to right, var(--accent-quiet), var(--accent));
  transform: scaleX(0);
  transform-origin: left;
}

/* ---------- Skip link --------------------------------------------------- */

.skip-link {
  position: absolute;
  left: var(--sp-4);
  top: -100%;
  z-index: var(--z-overlay);
  background: var(--accent);
  color: var(--accent-on);
  padding: var(--sp-3) var(--sp-5);
  border-radius: var(--r-sm);
  text-decoration: none;
  font-weight: 600;
  transition: top var(--dur-base) var(--ease-out);
}
.skip-link:focus-visible { top: var(--sp-4); }

/* ---------- Shell ------------------------------------------------------- */

.wrap { max-width: var(--wrap-max); margin: 0 auto; padding: 0 var(--sp-6); }
@media (max-width: 640px) { .wrap { padding: 0 var(--sp-5); } }

section {
  position: relative;
  z-index: var(--z-raised);
  /* Optical asymmetry: bottom pad slightly heavier than top */
  padding: var(--sp-11) 0 var(--sp-12);
  background: var(--bg);
  color: var(--text-body);
}

.section-head { max-width: 46rem; margin-bottom: var(--sp-9); }
.section-head--wide { max-width: 58rem; }

.eyebrow {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-2);
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.14em;
  margin-bottom: var(--sp-4);
}
.eyebrow::before {
  content: '';
  width: 1.75rem;
  height: 1px;
  background: currentColor;
  opacity: 0.6;
}

.section-head h2 { font-size: var(--fs-2xl); }
.section-head p {
  margin-top: var(--sp-4);
  color: var(--text-muted);
  font-size: var(--fs-md);
  max-width: var(--measure);
}

/* ---------- Nav --------------------------------------------------------- */

.nav {
  position: fixed;
  inset: 0 0 auto 0;
  z-index: var(--z-nav);
  background: var(--nav-bg);
  backdrop-filter: blur(14px) saturate(140%);
  -webkit-backdrop-filter: blur(14px) saturate(140%);
  border-bottom: 1px solid var(--nav-border);
  transition: border-color var(--dur-base) var(--ease-out),
              background var(--dur-base) var(--ease-out);
}
.nav.is-scrolled { --nav-border: var(--border-hairline); }

.nav-inner {
  max-width: var(--wrap-max);
  margin: 0 auto;
  padding: var(--sp-3) var(--sp-6);
  display: flex;
  align-items: center;
  gap: var(--sp-5);
}
@media (max-width: 640px) { .nav-inner { padding: var(--sp-3) var(--sp-5); } }

.brand {
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  font-family: var(--font-display);
  font-weight: 700;
  font-size: 1.06rem;
  letter-spacing: -0.02em;
  color: var(--text-strong);
  text-decoration: none;
  margin-right: auto;
}
.brand svg { width: 30px; height: 30px; flex: none; }
.brand .brand-sub {
  display: block;
  font-family: var(--font-mono);
  font-size: 0.6rem;
  font-weight: 400;
  letter-spacing: 0.16em;
  color: var(--text-faint);
  text-transform: uppercase;
  margin-top: 1px;
}

.nav-links { display: flex; gap: var(--sp-6); font-size: var(--fs-sm); }
.nav-links a {
  position: relative;
  color: var(--text-muted);
  text-decoration: none;
  padding-bottom: 3px;
  transition: color var(--dur-fast) var(--ease-out);
}
.nav-links a::after {
  content: '';
  position: absolute;
  inset: auto 0 0 0;
  height: 1px;
  background: var(--accent);
  transform: scaleX(0);
  transform-origin: left;
  transition: transform var(--dur-base) var(--ease-out);
}
.nav-links a:hover { color: var(--text-strong); }
.nav-links a:hover::after,
.nav-links a[aria-current='true']::after { transform: scaleX(1); }
.nav-links a[aria-current='true'] { color: var(--accent); }

.nav-cta {
  font-size: var(--fs-sm);
  font-weight: 500;
  padding: 0.55rem 1.1rem;
  border: 1px solid var(--accent);
  color: var(--accent);
  text-decoration: none;
  border-radius: var(--r-sm);
  white-space: nowrap;
  transition: background var(--dur-fast) var(--ease-out),
              color var(--dur-fast) var(--ease-out),
              transform var(--dur-fast) var(--ease-out);
}
.nav-cta:hover { background: var(--accent); color: var(--accent-on); }
.nav-cta:active { transform: scale(0.97); }

.nav-toggle {
  display: none;
  background: none;
  border: none;
  padding: var(--sp-2);
  cursor: pointer;
  border-radius: var(--r-sm);
}
.nav-toggle span {
  display: block;
  width: 22px;
  height: 2px;
  background: var(--text-strong);
  margin: 5px 0;
  transition: transform var(--dur-base) var(--ease-out), opacity var(--dur-fast) linear;
}
.nav-toggle[aria-expanded='true'] span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle[aria-expanded='true'] span:nth-child(2) { opacity: 0; }
.nav-toggle[aria-expanded='true'] span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

@media (max-width: 900px) {
  .nav-toggle { display: block; order: 3; }
  .nav-cta { order: 2; }
  .nav-links {
    display: none;
    order: 4;
    flex-direction: column;
    gap: 0;
    width: 100%;
    border-top: 1px solid var(--border-hairline);
    margin-top: var(--sp-3);
  }
  .nav-links.is-open { display: flex; }
  .nav-links a {
    padding: var(--sp-4) var(--sp-1);
    border-bottom: 1px solid var(--border-hairline);
    font-size: var(--fs-md);
  }
  .nav-links a:last-child { border-bottom: none; }
  .nav-links a::after { display: none; }
  .nav-inner { flex-wrap: wrap; }
}

/* ---------- Buttons ----------------------------------------------------- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--sp-2);
  padding: 0.85rem 1.6rem;
  font-size: var(--fs-sm);
  font-weight: 600;
  border: 1px solid transparent;
  border-radius: var(--r-sm);
  text-decoration: none;
  cursor: pointer;
  white-space: nowrap;
  transition: background var(--dur-fast) var(--ease-out),
              color var(--dur-fast) var(--ease-out),
              border-color var(--dur-fast) var(--ease-out),
              transform var(--dur-fast) var(--ease-spring),
              box-shadow var(--dur-base) var(--ease-out);
}
.btn--primary {
  background: var(--btn-bg);
  color: var(--btn-fg);
  box-shadow: var(--shadow-sm);
}
.btn--primary:hover { background: var(--btn-bg-hover); box-shadow: var(--shadow-md); transform: translateY(-1px); }
.btn--primary:active { background: var(--btn-bg-active); transform: scale(0.98) translateY(0); box-shadow: var(--shadow-sm); }
.btn--primary[disabled], .btn--primary[aria-disabled='true'] {
  background: var(--btn-bg-disabled);
  color: var(--btn-fg-disabled);
  cursor: not-allowed;
  transform: none;
  box-shadow: none;
}
.btn--ghost {
  background: transparent;
  color: var(--btn-ghost-fg);
  border-color: var(--btn-ghost-border);
}
.btn--ghost:hover { color: var(--btn-ghost-fg-hover); border-color: var(--accent); }
.btn--ghost:active { transform: scale(0.98); }

.link-quiet {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-2);
  color: var(--text-muted);
  font-size: var(--fs-sm);
  text-decoration: none;
  border-bottom: 1px solid var(--border-strong);
  padding-bottom: 2px;
  transition: color var(--dur-fast) var(--ease-out), border-color var(--dur-fast) var(--ease-out);
}
.link-quiet:hover { color: var(--accent); border-color: var(--accent); }
.link-quiet .arrow { transition: transform var(--dur-base) var(--ease-spring); }
.link-quiet:hover .arrow { transform: translateX(3px); }

/* ---------- Hero -------------------------------------------------------- */

.hero {
  position: relative;
  min-height: 100dvh;
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
  align-items: center;
  gap: var(--sp-8);
  padding: 8rem 0 var(--sp-9);
  overflow: hidden;
  background:
    radial-gradient(ellipse 70% 55% at 78% 42%, var(--card-glow), transparent 70%),
    radial-gradient(ellipse 55% 45% at 12% 88%, color-mix(in srgb, var(--c-aqua-300) 14%, transparent), transparent 70%),
    linear-gradient(to bottom, var(--bg-raised), var(--bg-deep));
}
.hero > .wrap { grid-column: 1; width: 100%; }
.hero-visual { grid-column: 2; padding-right: var(--sp-6); }

@media (max-width: 980px) {
  .hero {
    grid-template-columns: 1fr;
    align-content: center;
    padding-top: 7rem;
    gap: var(--sp-7);
  }
  .hero > .wrap, .hero-visual { grid-column: 1; }
  .hero-visual { padding: 0 var(--sp-5); max-width: 34rem; margin: 0 auto; }
}

.hero-eyebrow {
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.16em;
  margin-bottom: var(--sp-5);
  display: flex;
  align-items: center;
  gap: var(--sp-3);
}
.hero-eyebrow .dot {
  width: 6px; height: 6px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 0 0 var(--accent);
  animation: pulse 2.4s var(--ease-out) infinite;
}
@keyframes pulse {
  0%   { box-shadow: 0 0 0 0 var(--card-glow); }
  70%  { box-shadow: 0 0 0 10px transparent; }
  100% { box-shadow: 0 0 0 0 transparent; }
}

.hero h1 { font-size: var(--fs-hero); max-width: 14ch; }
.hero h1 .line { display: block; overflow: hidden; padding-bottom: 0.06em; }
.hero h1 .line > span { display: block; will-change: transform; }
.hero h1 em {
  font-style: normal;
  color: var(--accent);
}

.hero-sub {
  margin-top: var(--sp-5);
  max-width: 44ch;
  font-size: var(--fs-md);
  color: var(--text-muted);
}

.hero-cta-row {
  margin-top: var(--sp-7);
  display: flex;
  align-items: center;
  gap: var(--sp-5);
  flex-wrap: wrap;
}

.hero-readout {
  margin-top: var(--sp-8);
  display: flex;
  gap: var(--sp-6);
  flex-wrap: wrap;
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  color: var(--text-faint);
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
.hero-readout div { display: flex; flex-direction: column; gap: 2px; }
.hero-readout b {
  font-size: var(--fs-md);
  font-weight: 500;
  color: var(--text-strong);
  letter-spacing: -0.01em;
  text-transform: none;
}

.scroll-cue {
  position: absolute;
  left: var(--sp-6);
  bottom: var(--sp-5);
  display: flex;
  align-items: center;
  gap: var(--sp-3);
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  color: var(--text-faint);
  text-transform: uppercase;
  letter-spacing: 0.12em;
}
.scroll-cue .bar {
  width: 1px; height: 36px;
  background: var(--border-strong);
  position: relative;
  overflow: hidden;
}
.scroll-cue .bar::after {
  content: '';
  position: absolute;
  inset: -100% 0 auto 0;
  height: 100%;
  background: var(--accent);
  animation: scrollbar 1.9s var(--ease-out) infinite;
}
@keyframes scrollbar { 0% { top: -100%; } 55% { top: 0; } 100% { top: 100%; } }
@media (max-width: 980px) { .scroll-cue { display: none; } }

/* ---------- Problem / stats strip --------------------------------------- */

.problem { background: var(--bg-deep); }
.problem .wrap {
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 1fr);
  gap: var(--sp-9);
  align-items: center;
}
@media (max-width: 900px) { .problem .wrap { grid-template-columns: 1fr; gap: var(--sp-7); } }
.problem h2 { font-size: var(--fs-xl); max-width: 20ch; }
.problem p { margin-top: var(--sp-4); color: var(--text-muted); max-width: 48ch; }

.stat-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1px;
  background: var(--border-hairline);
  border: 1px solid var(--border-hairline);
  border-radius: var(--r-md);
  overflow: hidden;
}
.stat { background: var(--bg-raised); padding: var(--sp-6) var(--sp-5); }
.stat b {
  font-family: var(--font-display);
  font-variant-numeric: tabular-nums;
  font-size: 2.15rem;
  font-weight: 700;
  letter-spacing: -0.03em;
  display: block;
  color: var(--text-strong);
}
.stat .unit { color: var(--accent); }
.stat span {
  display: block;
  margin-top: var(--sp-2);
  font-size: var(--fs-xs);
  color: var(--text-faint);
  line-height: 1.45;
}

/* ---------- Norms strip ------------------------------------------------- */

.norms {
  padding: var(--sp-6) 0;
  border-block: 1px solid var(--border-hairline);
  background: var(--bg);
}
.norms .wrap {
  display: flex;
  align-items: center;
  gap: var(--sp-7);
  flex-wrap: wrap;
  justify-content: space-between;
}
.norms .label {
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-faint);
}
.norms ul {
  display: flex;
  gap: var(--sp-6);
  flex-wrap: wrap;
  list-style: none;
}
.norms li {
  font-family: var(--font-mono);
  font-size: var(--fs-sm);
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: var(--sp-2);
}
.norms li::before {
  content: '';
  width: 5px; height: 5px;
  border-radius: 1px;
  background: var(--accent);
  transform: rotate(45deg);
}

/* ---------- About ------------------------------------------------------- */

.about .wrap {
  display: grid;
  grid-template-columns: minmax(0, 0.9fr) minmax(0, 1.1fr);
  gap: var(--sp-9);
}
@media (max-width: 900px) { .about .wrap { grid-template-columns: 1fr; gap: var(--sp-6); } }
.about-body p { max-width: var(--measure); font-size: var(--fs-md); color: var(--text-muted); }
.about-body p + p { margin-top: var(--sp-4); }
.about-pull {
  margin-top: var(--sp-6);
  padding-left: var(--sp-5);
  border-left: 2px solid var(--accent);
  font-family: var(--font-display);
  font-size: var(--fs-lg);
  line-height: 1.35;
  color: var(--text-strong);
  letter-spacing: -0.02em;
}

/* ---------- Flow stage (scroll-pinned diagram) -------------------------- */

.flow-section { background: var(--bg-deep); }
/* Vlevo schéma, vpravo readout, který se přepisuje podle pozice ve scrollu. */
.flow-stage {
  position: relative;
  display: grid;
  grid-template-columns: minmax(0, 1.05fr) minmax(0, 0.95fr);
  align-items: center;
  gap: var(--sp-6);
  /* Scéna se pinuje pod lištou, takže se do okna musí vejít i s ní. */
  height: min(76vh, calc(100vh - 9rem));
  min-height: 460px;
  margin-top: var(--sp-5);
  padding-right: var(--sp-7);
  background: var(--bg-raised);
  border: 1px solid var(--border-hairline);
  border-radius: var(--r-lg);
  overflow: hidden;
  box-shadow: var(--shadow-lg);
}
.flow-scene { position: relative; min-width: 0; height: 100%; }
.flow-stage svg { width: 100%; height: 100%; }

.flow-readout { min-width: 0; }

.flow-step {
  font-size: var(--fs-micro);
  text-transform: uppercase;
  letter-spacing: 0.18em;
  color: var(--text-faint);
}
.flow-class {
  margin-top: var(--sp-3);
  font-family: var(--font-display);
  font-size: clamp(3rem, 6.5vw, 5.5rem);
  font-weight: 700;
  line-height: 0.95;
  letter-spacing: -0.04em;
  color: var(--accent);
}
.flow-caption {
  margin-top: var(--sp-4);
  max-width: 32ch;
  font-size: var(--fs-md);
  color: var(--text-muted);
}

.flow-meter {
  margin-top: var(--sp-7);
  padding-top: var(--sp-5);
  border-top: 1px solid var(--border-hairline);
  max-width: 32rem;
}
.flow-meter-row {
  display: flex;
  align-items: baseline;
  gap: var(--sp-4);
}
.flow-meter-label {
  font-size: var(--fs-micro);
  text-transform: uppercase;
  letter-spacing: 0.14em;
  color: var(--text-faint);
}
.flow-meter-value {
  font-family: var(--font-display);
  font-size: clamp(1.6rem, 3vw, 2.4rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  color: var(--text-strong);
}
.flow-segments {
  display: grid;
  grid-template-columns: repeat(5, minmax(0, 1fr));
  gap: var(--sp-2);
  margin-top: var(--sp-4);
}
.flow-segments i {
  display: block;
  height: 2px;
  border-radius: 2px;
  background: var(--border-hairline);
  transition: background var(--dur-base) var(--ease-out);
}
.flow-segments i.is-on { background: var(--accent); }

@media (max-width: 900px) {
  .flow-stage {
    grid-template-columns: 1fr;
    align-content: center;
    gap: var(--sp-4);
    height: auto;
    padding: var(--sp-6);
  }
  .flow-scene { height: 46vh; min-height: 300px; }
  .flow-meter { margin-top: var(--sp-5); }
}

/* ---------- Datasheet --------------------------------------------------- */

.datasheet {
  width: 100%;
  border-collapse: collapse;
  border: 1px solid var(--datasheet-line);
  border-radius: var(--r-md);
  overflow: hidden;
  font-size: var(--fs-sm);
  background: var(--bg-raised);
}
.datasheet caption {
  caption-side: top;
  text-align: left;
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-faint);
  padding-bottom: var(--sp-3);
}
.datasheet th, .datasheet td {
  text-align: left;
  padding: var(--sp-4) var(--sp-5);
  border-bottom: 1px solid var(--datasheet-line);
  vertical-align: baseline;
}
.datasheet thead th {
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  font-weight: 500;
  text-transform: uppercase;
  letter-spacing: 0.12em;
  color: var(--text-faint);
  background: var(--bg-inset);
}
.datasheet tbody tr { transition: background var(--dur-fast) linear; }
.datasheet tbody tr:hover { background: var(--datasheet-row-hover); }
.datasheet tbody tr:last-child th,
.datasheet tbody tr:last-child td { border-bottom: none; }
.datasheet tbody th {
  font-family: var(--font-body);
  font-weight: 500;
  color: var(--text-body);
  width: 34%;
}
.datasheet td.value {
  font-family: var(--font-display);
  font-variant-numeric: tabular-nums;
  font-size: var(--fs-md);
  font-weight: 600;
  color: var(--text-strong);
  letter-spacing: -0.02em;
  width: 26%;
}
.datasheet td.unit {
  font-family: var(--font-mono);
  font-size: var(--fs-xs);
  color: var(--accent);
}
.datasheet td.note { color: var(--text-faint); font-size: var(--fs-xs); }
.datasheet-scroll { overflow-x: auto; -webkit-overflow-scrolling: touch; }

/* On a narrow screen the four columns cannot sit side by side, and both
   hiding the note column and side-scrolling proved wrong answers. Each row
   becomes a card instead: parameter as its label, value with unit on one
   line, note underneath. Nothing is dropped and nothing scrolls sideways. */
@media (max-width: 720px) {
  .datasheet { display: block; border: none; background: none; }
  .datasheet caption { display: block; }
  .datasheet thead { display: none; }
  .datasheet tbody { display: grid; gap: var(--sp-3); }

  .datasheet tbody tr {
    display: block;
    background: var(--bg-raised);
    border: 1px solid var(--datasheet-line);
    border-radius: var(--r-md);
    padding: var(--sp-4) var(--sp-5);
  }
  /* The desktop row-hover highlight would flash on tap here. */
  .datasheet tbody tr:hover { background: var(--bg-raised); }

  .datasheet th, .datasheet td {
    border-bottom: none;
    padding: 0;
    width: auto;
  }
  .datasheet tbody th {
    display: block;
    font-family: var(--font-mono);
    font-size: var(--fs-micro);
    font-weight: 500;
    text-transform: uppercase;
    letter-spacing: 0.1em;
    color: var(--text-faint);
    margin-bottom: var(--sp-2);
  }
  /* Value and unit flow as one line of text, so a long value wraps like a
     sentence instead of one word per grid-squeezed row. */
  .datasheet td.value { display: inline; font-size: var(--fs-lg); }
  .datasheet td.unit { display: inline; margin-left: var(--sp-2); }
  .datasheet td.note {
    display: block;
    margin-top: var(--sp-2);
  }
}

/* ---------- Bento: applications ----------------------------------------- */

.bento {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--sp-4);
}
.bento .tile {
  position: relative;
  display: flex;
  flex-direction: column;
  min-height: 15rem;
  padding: var(--sp-6);
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--r-lg);
  overflow: hidden;
  isolation: isolate;
  transition: border-color var(--dur-base) var(--ease-out),
              transform var(--dur-base) var(--ease-out);
}
/* Spotlight border that tracks the cursor */
.bento .tile::before {
  content: '';
  position: absolute;
  inset: -1px;
  z-index: -1;
  border-radius: inherit;
  background: radial-gradient(
    18rem 18rem at var(--mx, 50%) var(--my, 50%),
    var(--card-glow),
    transparent 65%
  );
  opacity: 0;
  transition: opacity var(--dur-base) var(--ease-out);
}
.bento .tile:hover { border-color: var(--card-border-hover); transform: translateY(-3px); }
.bento .tile:hover::before { opacity: 1; }

.tile .icon {
  width: 34px; height: 34px;
  color: var(--accent);
  transition: transform var(--dur-base) var(--ease-spring);
}
.tile:hover .icon { transform: translateY(-3px); }
/* Obsah teče shora, ne odspoda: nadpisy tak začínají ve všech dlaždicích
   ve stejné výšce. min-height drží místo pro dvouřádkový nadpis, aby se
   pod ním srovnaly i odstavce. */
.tile h3 {
  font-size: var(--fs-lg);
  margin-top: var(--sp-5);
  min-height: calc(2 * 1.06em);
}
.tile p { margin-top: var(--sp-2); font-size: var(--fs-sm); color: var(--text-muted); max-width: 40ch; }
.tile .tile-tag {
  position: absolute;
  top: var(--sp-5);
  right: var(--sp-5);
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  letter-spacing: 0.1em;
  color: var(--text-faint);
  border: 1px solid var(--border-hairline);
  padding: 2px var(--sp-2);
  border-radius: var(--r-xs);
}

/* Sortiment: stejné dlaždice, jen na střed a jako odkaz do poptávky. */
.bento--range .tile .icon { width: 40px; height: 40px; }
.bento--range .tile {
  align-items: center;
  text-align: center;
  justify-content: center;
  min-height: 13rem;
  text-decoration: none;
}
.bento--range .tile h3 { min-height: 0; margin-top: var(--sp-4); }
.bento--range .tile p { margin-top: var(--sp-2); max-width: 26ch; }

@media (max-width: 900px) {
  .bento { grid-template-columns: repeat(2, minmax(0, 1fr)); }
}
@media (max-width: 560px) {
  .bento { grid-template-columns: 1fr; }
  .tile h3 { min-height: 0; }
}

/* ---------- Savings calculator ------------------------------------------ */

.calc {
  display: grid;
  grid-template-columns: minmax(0, 1.1fr) minmax(0, 0.9fr);
  gap: var(--sp-6);
  align-items: stretch;
}
@media (max-width: 860px) { .calc { grid-template-columns: 1fr; } }

.calc-inputs {
  background: var(--card-bg);
  border: 1px solid var(--card-border);
  border-radius: var(--r-xl);
  padding: var(--sp-7);
  display: grid;
  gap: var(--sp-6);
  box-shadow: var(--shadow-sm);
}
@media (max-width: 560px) { .calc-inputs { padding: var(--sp-5); } }

.calc-row { display: grid; gap: var(--sp-2); }
.calc-row .calc-label {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: var(--sp-3);
  font-size: var(--fs-xs);
  font-weight: 500;
  color: var(--text-body);
}
.calc-row output {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--fs-sm);
  color: var(--accent);
  white-space: nowrap;
}

.calc-row input[type='range'] {
  width: 100%;
  accent-color: var(--accent);
  cursor: pointer;
}
.calc-row input[type='number'] {
  width: 100%;
  padding: 0.65rem 0.8rem;
  background: var(--field-bg);
  color: var(--field-fg);
  border: 1px solid var(--field-border);
  border-radius: var(--r-sm);
  font-size: var(--fs-sm);
  font-variant-numeric: tabular-nums;
}
.calc-row input[type='number']:focus-visible {
  outline: none;
  border-color: var(--field-border-focus);
  box-shadow: 0 0 0 3px var(--card-glow);
}

.calc-result {
  position: relative;
  display: flex;
  flex-direction: column;
  justify-content: center;
  gap: var(--sp-4);
  padding: var(--sp-7);
  border-radius: var(--r-xl);
  background:
    radial-gradient(ellipse 90% 70% at 20% 0%, var(--card-glow), transparent 70%),
    var(--card-bg);
  border: 1px solid var(--card-border-hover);
  box-shadow: var(--shadow-md);
  overflow: hidden;
}
.calc-result .calc-kicker {
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--text-faint);
}
.calc-result .calc-czk {
  font-family: var(--font-display);
  font-variant-numeric: tabular-nums;
  font-size: clamp(2.4rem, 4.6vw, 3.4rem);
  font-weight: 700;
  letter-spacing: -0.03em;
  line-height: 1;
  color: var(--accent);
}
.calc-result .calc-kwh {
  font-family: var(--font-mono);
  font-variant-numeric: tabular-nums;
  font-size: var(--fs-sm);
  color: var(--text-body);
}
.calc-result .calc-note {
  font-size: var(--fs-micro);
  color: var(--text-faint);
  max-width: 34ch;
}
.calc-result .btn { align-self: flex-start; margin-top: var(--sp-2); }

/* ---------- Water section ----------------------------------------------- */

.water .wrap {
  display: grid;
  grid-template-columns: minmax(0, 1fr) 17rem;
  gap: var(--sp-9);
  align-items: center;
}
@media (max-width: 900px) {
  .water .wrap { grid-template-columns: 1fr; gap: var(--sp-6); }
  .water-visual { order: -1; max-width: 14rem; margin: 0 auto; }
}
.water-visual { width: 100%; }
.water-body p { max-width: var(--measure); color: var(--text-muted); font-size: var(--fs-md); }
.water-body .link-quiet { margin-top: var(--sp-6); }
.water-specs {
  display: flex;
  gap: 1px;
  background: var(--border-hairline);
  border: 1px solid var(--border-hairline);
  border-radius: var(--r-md);
  overflow: hidden;
  margin-top: var(--sp-6);
  flex-wrap: wrap;
}
.water-spec { background: var(--bg-raised); padding: var(--sp-4) var(--sp-5); flex: 1 1 8rem; }
.water-spec .label {
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  color: var(--text-faint);
  text-transform: uppercase;
  letter-spacing: 0.1em;
}
.water-spec .val {
  font-family: var(--font-display);
  font-variant-numeric: tabular-nums;
  font-size: var(--fs-lg);
  font-weight: 600;
  letter-spacing: -0.02em;
  color: var(--text-strong);
  margin-top: var(--sp-1);
}
.water-spec .val .unit { font-size: var(--fs-xs); font-weight: 400; color: var(--accent); }

/* ---------- Process ----------------------------------------------------- */

.process-list {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: var(--sp-6);
  counter-reset: step;
  list-style: none;
}
@media (max-width: 820px) { .process-list { grid-template-columns: 1fr; gap: var(--sp-5); } }
.process-list li {
  position: relative;
  padding-top: var(--sp-6);
  border-top: 1px solid var(--border-hairline);
  counter-increment: step;
}
.process-list li::before {
  content: counter(step, decimal-leading-zero);
  position: absolute;
  top: var(--sp-4);
  left: 0;
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  color: var(--accent);
  letter-spacing: 0.1em;
}
.process-list h3 { margin-top: var(--sp-5); font-size: var(--fs-md); }
.process-list p { margin-top: var(--sp-2); font-size: var(--fs-sm); color: var(--text-muted); }

/* ---------- Benefits ---------------------------------------------------- */

.benefits { background: var(--bg-deep); }
.benefit-row {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 1px;
  background: var(--border-hairline);
  border: 1px solid var(--border-hairline);
  border-radius: var(--r-md);
  overflow: hidden;
}
@media (max-width: 820px) { .benefit-row { grid-template-columns: 1fr; } }
.benefit { background: var(--bg-raised); padding: var(--sp-7) var(--sp-6); }
.benefit .num { font-family: var(--font-mono); color: var(--accent); font-size: var(--fs-xs); letter-spacing: 0.1em; }
.benefit h3 { margin-top: var(--sp-4); font-size: var(--fs-md); }
.benefit p { margin-top: var(--sp-3); font-size: var(--fs-sm); color: var(--text-muted); }

/* ---------- FAQ --------------------------------------------------------- */

.faq-grid {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--sp-7) var(--sp-9);
}
@media (max-width: 820px) { .faq-grid { grid-template-columns: 1fr; gap: var(--sp-6); } }
.faq-grid dt {
  font-family: var(--font-display);
  font-weight: 600;
  font-size: var(--fs-md);
  color: var(--text-strong);
  letter-spacing: -0.02em;
}
.faq-grid dd { margin-top: var(--sp-2); font-size: var(--fs-sm); color: var(--text-muted); max-width: 46ch; }

/* ---------- Contact / clean panel --------------------------------------- */

.contact {
  background: var(--bg);
  color: var(--text-body);
  padding: var(--sp-12) 0;
  position: relative;
}
.contact::before {
  /* the "filtered air" edge where the dark side meets the clean room */
  content: '';
  position: absolute;
  inset: 0 0 auto 0;
  height: 1px;
  background: linear-gradient(to right, transparent, var(--accent-quiet), transparent);
}
.contact .wrap {
  display: grid;
  grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.15fr);
  gap: var(--sp-9);
  align-items: start;
}
@media (max-width: 900px) { .contact .wrap { grid-template-columns: 1fr; gap: var(--sp-7); } }
.contact h2 { font-size: var(--fs-2xl); max-width: 16ch; }
.contact-lede { margin-top: var(--sp-4); color: var(--text-muted); max-width: 40ch; }

.contact-direct { margin-top: var(--sp-7); display: flex; flex-direction: column; gap: var(--sp-3); }
.contact-direct a {
  display: inline-flex;
  align-items: center;
  gap: var(--sp-3);
  font-family: var(--font-display);
  font-size: var(--fs-md);
  color: var(--text-strong);
  text-decoration: none;
  width: fit-content;
  transition: color var(--dur-fast) var(--ease-out);
}
.contact-direct a:hover { color: var(--accent); }
.contact-direct svg { width: 17px; height: 17px; color: var(--accent); flex: none; }
.contact-direct .meta { font-size: var(--fs-xs); color: var(--text-faint); font-family: var(--font-mono); }

/* the form itself sits on the clean side */
.form-panel {
  background: var(--bg-raised);
  border: 1px solid var(--border-hairline);
  border-radius: var(--r-xl);
  padding: var(--sp-7);
  box-shadow: var(--shadow-lg);
}
@media (max-width: 560px) { .form-panel { padding: var(--sp-5); border-radius: var(--r-lg); } }

.field-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--sp-4);
}
@media (max-width: 620px) { .field-grid { grid-template-columns: 1fr; } }
.field { display: flex; flex-direction: column; gap: var(--sp-2); }
.field--full { grid-column: 1 / -1; }

.field label {
  font-size: var(--fs-xs);
  font-weight: 500;
  color: var(--text-body);
  display: flex;
  align-items: baseline;
  gap: var(--sp-2);
}
.field label .opt {
  font-family: var(--font-mono);
  font-size: var(--fs-micro);
  color: var(--text-faint);
  text-transform: uppercase;
  letter-spacing: 0.08em;
}
.field label .req { color: var(--accent); }

.field input,
.field select,
.field textarea {
  width: 100%;
  padding: 0.8rem 0.9rem;
  background: var(--field-bg);
  color: var(--field-fg);
  border: 1px solid var(--field-border);
  border-radius: var(--r-sm);
  font-size: var(--fs-sm);
  transition: border-color var(--dur-fast) var(--ease-out),
              box-shadow var(--dur-fast) var(--ease-out);
}
.field textarea { resize: vertical; min-height: 6.5rem; line-height: 1.55; }
.field input::placeholder, .field textarea::placeholder { color: var(--field-placeholder); }
.field select { appearance: none; cursor: pointer;
  background-image: linear-gradient(45deg, transparent 50%, currentColor 50%),
                    linear-gradient(135deg, currentColor 50%, transparent 50%);
  background-position: right 1.05rem center, right 0.75rem center;
  background-size: 5px 5px, 5px 5px;
  background-repeat: no-repeat;
  padding-right: 2.2rem;
}
.field :is(input, select, textarea):focus-visible {
  outline: none;
  border-color: var(--field-border-focus);
  box-shadow: 0 0 0 3px var(--card-glow);
}
.field[data-invalid='true'] :is(input, select, textarea) { border-color: var(--field-invalid); }
.field .err {
  font-size: var(--fs-micro);
  color: var(--danger);
  min-height: 1em;
}
.field .err:empty { display: none; }

/* honeypot — visually gone but not display:none, so naive bots still see it */
.hp-field {
  position: absolute;
  left: -9999px;
  width: 1px;
  height: 1px;
  overflow: hidden;
  opacity: 0;
  pointer-events: none;
}

.consent {
  grid-column: 1 / -1;
  display: grid;
  grid-template-columns: auto 1fr;
  gap: var(--sp-3);
  align-items: start;
  font-size: var(--fs-xs);
  color: var(--text-muted);
}
/* The consent label is a sentence with a link inside; the flex layout the
   generic .field label carries would turn each text chunk into a non-wrapping
   flex item and push the line out of the panel. */
.consent label { display: inline; }
.consent input[type='checkbox'] {
  width: 1.05rem; height: 1.05rem;
  margin-top: 0.15rem;
  accent-color: var(--accent);
  cursor: pointer;
}
.consent a { color: var(--text-body); text-decoration: underline; text-underline-offset: 2px; }
.consent a:hover { color: var(--accent); }
.consent .err { grid-column: 2; }

.challenge { grid-column: 1 / -1; }
.challenge[hidden] { display: none; }

.form-actions {
  grid-column: 1 / -1;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--sp-4);
  flex-wrap: wrap;
  margin-top: var(--sp-2);
}
.form-actions .btn { flex: 0 0 auto; }
.form-hint { font-family: var(--font-mono); font-size: var(--fs-micro); color: var(--text-faint); }

.form-status {
  grid-column: 1 / -1;
  font-size: var(--fs-sm);
  padding: var(--sp-4);
  border-radius: var(--r-sm);
  border: 1px solid var(--border-hairline);
  background: var(--bg-inset);
}
/* Collapsed, not display:none — a live region removed from the tree would
   not announce its first message when JS fills it in. */
.form-status:empty {
  padding: 0;
  border: none;
  min-height: 0;
}
.form-status[data-tone='ok'] { border-color: var(--ok); color: var(--ok); }
.form-status[data-tone='error'] { border-color: var(--danger); color: var(--danger); }
.form-status[data-tone='pending'] { color: var(--text-muted); }

/* spinner shown while the request is in flight */
.btn .spinner {
  width: 14px; height: 14px;
  border: 2px solid currentColor;
  border-right-color: transparent;
  border-radius: 50%;
  animation: spin 0.7s linear infinite;
}
@keyframes spin { to { transform: rotate(360deg); } }

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

footer {
  border-top: 1px solid var(--border-hairline);
  padding: var(--sp-7) 0;
  background: var(--bg-deep);
  position: relative;
  z-index: var(--z-raised);
}
.footer-inner {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: var(--sp-5);
  flex-wrap: wrap;
  font-size: var(--fs-xs);
  color: var(--text-faint);
}
.footer-links { display: flex; gap: var(--sp-5); flex-wrap: wrap; }
.footer-links a,
.footer-links button {
  text-decoration: none;
  transition: color var(--dur-fast) var(--ease-out);
}
.footer-links button {
  font: inherit;
  color: inherit;
  background: none;
  border: 0;
  padding: 0;
  cursor: pointer;
}
.footer-links a:hover,
.footer-links button:hover { color: var(--accent); }

/* ---------- Diagram artwork (inline SVG) -------------------------------- */
/* An SVG presentation attribute cannot hold a var(), so the diagrams carry
   classes instead. That also means the artwork follows a .clean scope the same
   way the rest of the page does, with no second set of shapes.
   Nothing here declares `fill` on a shape that also gets one from markup or
   from app.js — a CSS declaration outranks a presentation attribute, and that
   would silently override the colours the script computes from the tokens. */

.hero-visual svg,
.water-visual svg { width: 100%; height: auto; }

/* The filter breathes: a slow drift that makes the light page feel like air
   is moving through it. The reduced-motion block at the bottom kills it. */
.hero-visual svg { animation: hero-float 7s ease-in-out infinite alternate; }
@keyframes hero-float {
  from { transform: translateY(0); }
  to   { transform: translateY(-10px); }
}

.svg-housing { fill: var(--bg-inset); stroke: var(--border-strong); stroke-width: 1; }
.svg-outline { fill: none; stroke: var(--border-strong); stroke-width: 1.6; }
.svg-edge    { stroke: var(--border-strong); stroke-width: 1.6; }
.svg-media   { fill: var(--accent); }
.svg-dust    { fill: var(--contaminant); }

/* Pocket walls: a hairline of the same aqua as the fill, so the tapered tip
   stays readable once the depth gradient has faded out. */
.svg-media-edge { stroke: var(--accent); stroke-width: 1; stroke-opacity: 0.45; }

/* Depth ramp inside a pocket: dense at the mouth where the dust loads, thin
   at the tip. Referenced by the <stop> elements of each gradient. */
.svg-stop-near { stop-color: var(--accent); stop-opacity: 0.6; }
.svg-stop-mid  { stop-color: var(--accent); stop-opacity: 0.3; }
.svg-stop-far  { stop-color: var(--accent); stop-opacity: 0.08; }

/* Streamlines. Raw air is grey, filtered air is aqua — the same rule the rest
   of the palette follows. app.js draws them on by animating the dash offset;
   they are deliberately left solid here so a scriptless page shows whole lines. */
.svg-flow { fill: none; stroke: var(--text-faint); stroke-width: 1.4; stroke-linecap: round; }
.svg-flow--clean { stroke: var(--accent); stroke-opacity: 0.75; }

.svg-core { fill: none; stroke: var(--border-hairline); stroke-width: 1.2; stroke-dasharray: 4 6; }
.svg-wound-bg { fill: var(--bg-inset); }
.svg-wound-line { stroke: var(--accent); stroke-width: 3; opacity: 0.38; }

.svg-label {
  fill: var(--text-faint);
  font-family: var(--font-mono);
  font-size: 11px;
  letter-spacing: 0.12em;
}
.svg-label--accent { fill: var(--accent); }

/* ---------- Cookie lišta -------------------------------------------------- */

.cookie-bar {
  position: fixed;
  left: var(--sp-5);
  right: var(--sp-5);
  bottom: var(--sp-5);
  z-index: 60;
  margin-inline: auto;
  max-width: 46rem;
  display: flex;
  align-items: center;
  gap: var(--sp-5);
  padding: var(--sp-5);
  background: var(--bg-raised);
  border: 1px solid var(--border-hairline);
  border-radius: var(--r-lg);
  box-shadow: var(--shadow-lg);
}
.cookie-bar[hidden] { display: none; }
.cookie-bar p {
  margin: 0;
  font-size: var(--fs-sm);
  color: var(--text-muted);
}
.cookie-bar a { color: var(--accent); text-decoration: underline; text-underline-offset: 2px; }
.cookie-bar-actions {
  display: flex;
  gap: var(--sp-3);
  flex-shrink: 0;
}
.cookie-bar .btn { white-space: nowrap; }

@media (max-width: 640px) {
  .cookie-bar {
    left: var(--sp-4);
    right: var(--sp-4);
    bottom: var(--sp-4);
    flex-direction: column;
    align-items: stretch;
    gap: var(--sp-4);
  }
  .cookie-bar-actions .btn { flex: 1; justify-content: center; }
}

/* ---------- Utilities --------------------------------------------------- */

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

/* Hidden-before-reveal only when JS is actually there: assets/js/head.js
   stamps .js on <html> before first paint. A no-JS visitor gets the whole
   page — including the inquiry form the PHP fallback exists for. */
.js [data-reveal] { opacity: 0; transform: translateY(1.5rem); }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after {
    animation-duration: 0.001ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.001ms !important;
  }
  .js [data-reveal] { opacity: 1; transform: none; }
  .hero h1 .line > span { transform: none; }
}