/* "How your Crate fills": the two inputs and the illustrative preview. */

.equation {
  display: grid;
  grid-template-columns: 1fr auto 1fr auto 1fr;
  align-items: center;
  gap: 16px;
  margin-bottom: clamp(40px, 6vw, 72px);
}
.equation__term {
  display: grid;
  justify-items: center;
  text-align: center;
  gap: 6px;
  padding: 20px 16px 22px;
  border: 1px solid var(--nm-black);
  border-radius: var(--r);
}
.equation__term--result { background: var(--nm-lime); box-shadow: var(--extrude); }
.equation__label { font-size: 20px; font-weight: 600; }
.equation__text { font-size: 14px; color: var(--nm-muted); }
.equation__term--result .equation__text { color: var(--nm-ink); }
.equation__op { font-size: 34px; font-weight: 300; line-height: 1; }
.equation__op svg { width: 30px; height: 30px; }

/* ----------------------------------------------------------- preview */

.preview {
  --fill: 0;
  display: grid;
  grid-template-columns: minmax(0, 0.85fr) minmax(0, 1.15fr);
  border: 1px solid var(--nm-black);
  border-radius: var(--r-lg);
  overflow: hidden;
  background: var(--nm-paper);
}

.preview__controls {
  display: flex;
  flex-direction: column;
  gap: 22px;
  padding: clamp(24px, 3vw, 44px);
  border-right: 1px solid var(--nm-black);
  background: var(--nm-bg);
}
.preview__kicker { font-size: 12px; font-weight: 500; letter-spacing: 0.12em; text-transform: uppercase; color: var(--nm-muted); }
.preview__title { margin-top: -12px; font-size: clamp(26px, 2.6vw, 36px); font-weight: 600; line-height: 1.1; letter-spacing: -0.02em; }
.preview__intro { margin-top: -8px; color: var(--nm-muted); font-size: 15px; }

.control { display: grid; gap: 10px; }
.control__top label { font-weight: 600; font-size: 16px; }
.control__scale { display: flex; justify-content: space-between; font-size: 12px; letter-spacing: 0.06em; text-transform: uppercase; color: var(--nm-muted); }

/* Range input styled like NullMask's cable: outlined pipe, lime core, keyhole-plate thumb. */
.range {
  --v: 50%;
  width: 100%;
  height: 32px;
  margin: 0;
  background: transparent;
  cursor: pointer;
  -webkit-appearance: none;
  appearance: none;
}
.range::-webkit-slider-runnable-track {
  height: 14px;
  border: 1.5px solid var(--nm-black);
  border-radius: 99px;
  background: linear-gradient(90deg, var(--nm-lime) 0 var(--v), var(--nm-paper) var(--v) 100%);
}
.range::-moz-range-track {
  height: 11px;
  border: 1.5px solid var(--nm-black);
  border-radius: 99px;
  background: var(--nm-paper);
}
.range::-moz-range-progress { height: 11px; border-radius: 99px; background: var(--nm-lime); }
.range::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 26px;
  height: 32px;
  margin-top: -10.5px;
  border: 1.5px solid var(--nm-black);
  border-radius: 6px;
  background:
    radial-gradient(circle at 50% 38%, var(--nm-black) 0 4px, transparent 4.5px),
    linear-gradient(var(--nm-black), var(--nm-black)) 50% 72% / 3px 9px no-repeat,
    var(--nm-lime);
  box-shadow: 3px 3px 0 var(--nm-black);
  transition: transform var(--t-fast);
}
.range::-moz-range-thumb {
  width: 24px;
  height: 30px;
  border: 1.5px solid var(--nm-black);
  border-radius: 6px;
  background:
    radial-gradient(circle at 50% 38%, var(--nm-black) 0 4px, transparent 4.5px),
    linear-gradient(var(--nm-black), var(--nm-black)) 50% 72% / 3px 9px no-repeat,
    var(--nm-lime);
  box-shadow: 3px 3px 0 var(--nm-black);
}
.range:active::-webkit-slider-thumb { transform: translate(-1px, -1px); }
.range:focus-visible { outline: 2px solid var(--nm-black); outline-offset: 4px; }

.preview__actions { display: flex; flex-wrap: wrap; gap: 8px; margin-top: 4px; }
.preview__note {
  padding: 12px 14px;
  border: 1px solid var(--nm-black);
  border-left: 6px solid var(--nm-black);
  border-radius: var(--r-sm);
  background: var(--nm-paper);
  font-size: 14px;
}

.preview__stage {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 16px;
  padding: clamp(20px, 3vw, 40px);
  background:
    radial-gradient(circle at 1px 1px, rgba(14, 15, 15, 0.28) 1.1px, transparent 1.6px) 0 0 / 14px 14px,
    var(--nm-paper);
}
.preview__status {
  align-self: flex-start;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 5px 10px;
  border: 1px solid var(--nm-black);
  border-radius: var(--r-sm);
  background: var(--nm-bg);
  font-size: 12px;
  font-weight: 500;
  letter-spacing: 0.08em;
  text-transform: uppercase;
}
.preview__crate { width: min(100%, 440px); aspect-ratio: 540 / 550; }
.preview__crate .crate { width: 100%; height: 100%; }

.tier-rail { width: 100%; max-width: 520px; }
.tier-rail__track {
  position: relative;
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  gap: 4px;
  height: 14px;
}
.tier-rail__seg {
  border: 1px solid var(--nm-black);
  border-radius: 3px;
  background: var(--nm-bg);
  transition: background-color 300ms;
}
.tier-rail__seg.is-reached { background: var(--c); }
.tier-rail__marker {
  --at: 0;
  position: absolute;
  top: -7px;
  left: calc(var(--at) * 100%);
  width: 4px;
  height: 28px;
  margin-left: -2px;
  background: var(--nm-black);
  border-radius: 2px;
  transition: left 420ms var(--ease-out);
}
.tier-rail__marker::after {
  content: '';
  position: absolute;
  left: 50%;
  top: -8px;
  width: 12px;
  height: 12px;
  transform: translateX(-50%) rotate(45deg);
  background: var(--nm-lime);
  border: 1.5px solid var(--nm-black);
}
.tier-rail__names {
  display: grid;
  grid-template-columns: repeat(5, 1fr);
  margin-top: 10px;
  font-size: 12px;
  font-weight: 500;
  text-align: center;
}

.preview__disclaimer {
  max-width: 520px;
  font-size: 12.5px;
  color: var(--nm-muted);
  text-align: center;
}

@media (max-width: 960px) {
  .preview { grid-template-columns: 1fr; }
  .preview__controls { border-right: 0; border-bottom: 1px solid var(--nm-black); }
}

@media (max-width: 760px) {
  .equation { grid-template-columns: 1fr; gap: 10px; }
  .equation__term { grid-template-columns: auto 1fr; justify-items: start; text-align: left; column-gap: 16px; padding: 14px 16px; }
  .equation__term .iso-icon { grid-row: span 2; width: 72px; height: 72px; }
  .equation__op { justify-self: center; font-size: 26px; }
  .equation__op svg { transform: rotate(90deg); width: 24px; height: 24px; }
  .tier-rail__names { font-size: 10px; }
}