/* Interactive Abacus Demo */

.demo-bg-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(80px);
  pointer-events: none;
  z-index: 0;
}
.demo-bg-orb-1 {
  width: 400px; height: 400px;
  background: var(--primary);
  opacity: 0.12;
  top: -10%; left: -5%;
}
.demo-bg-orb-2 {
  width: 500px; height: 500px;
  background: var(--accent);
  opacity: 0.1;
  bottom: -20%; right: -10%;
}

.demo-grid {
  display: grid;
  grid-template-columns: 1.3fr 1fr;
  gap: 28px;
  align-items: stretch;
}

/* Number display */
.demo-abacus {
  background: var(--card);
  border-radius: var(--radius-lg);
  padding: 32px;
  border: 1px solid var(--line);
  box-shadow: var(--shadow-md);
  position: relative;
  transition: background 0.4s;
}
.demo-abacus.mental {
  background: var(--ink);
  color: var(--bg);
}
.demo-abacus.mental .demo-number-label {
  color: rgba(255,255,255,0.55);
}

.demo-number-display {
  text-align: center;
  margin-bottom: 28px;
  position: relative;
}
.demo-number-label {
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink-muted);
  margin-bottom: 12px;
  transition: color 0.3s;
}
.demo-number-value {
  display: inline-flex;
  gap: 6px;
  font-family: var(--font-display);
  font-weight: 500;
}
.digit-slot {
  display: inline-block;
  width: 58px;
  height: 84px;
  overflow: hidden;
  background: var(--bg-alt);
  border-radius: 12px;
  position: relative;
}
.demo-abacus.mental .digit-slot {
  background: rgba(255,255,255,0.08);
}
.digit {
  display: flex;
  flex-direction: column;
  transition: transform 0.5s cubic-bezier(0.34, 1.26, 0.64, 1);
}
.digit > span {
  height: 84px;
  display: grid;
  place-items: center;
  font-size: 64px;
  line-height: 1;
  color: var(--primary);
  letter-spacing: -0.03em;
}
.demo-abacus.mental .digit > span {
  color: var(--accent-3);
}

/* Brain burst (mental mode flash) */
.brain-burst {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  pointer-events: none;
  z-index: 5;
}
.brain-burst > span {
  font-size: 56px;
  display: block;
  animation: brain-pop 0.9s cubic-bezier(0.34, 1.56, 0.64, 1);
}
.burst-ring {
  position: absolute;
  top: 50%; left: 50%;
  width: 60px; height: 60px;
  border-radius: 50%;
  border: 3px solid var(--accent-3);
  transform: translate(-50%, -50%);
  animation: burst-ring 0.9s ease-out forwards;
}
@keyframes brain-pop {
  0% { transform: scale(0); opacity: 0; }
  30% { transform: scale(1.3); opacity: 1; }
  100% { transform: scale(1); opacity: 0; }
}
@keyframes burst-ring {
  0% { transform: translate(-50%, -50%) scale(0.2); opacity: 1; }
  100% { transform: translate(-50%, -50%) scale(3); opacity: 0; }
}

/* Wooden abacus */
.abacus-wood {
  background: linear-gradient(135deg, #8B4513, #6B3410);
  border-radius: 16px;
  padding: 14px;
  box-shadow: inset 0 2px 0 rgba(255,255,255,0.08), inset 0 -2px 8px rgba(0,0,0,0.3);
  transition: opacity 0.4s, filter 0.4s;
}
.demo-abacus.mental .abacus-wood {
  opacity: 0.15;
  filter: blur(2px);
}
.abacus-frame {
  background: #F5E6D3;
  border-radius: 10px;
  padding: 20px 12px 28px;
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 0;
  position: relative;
  box-shadow: inset 0 1px 3px rgba(0,0,0,0.1);
}
.abacus-divider {
  position: absolute;
  left: 12px;
  right: 12px;
  top: 74px;
  height: 6px;
  background: linear-gradient(180deg, #8B4513, #6B3410);
  border-radius: 2px;
  box-shadow: 0 1px 2px rgba(0,0,0,0.2);
  z-index: 2;
}
.abacus-rod {
  position: relative;
  height: 280px;
  display: flex;
  flex-direction: column;
  align-items: center;
}
.rod-line {
  position: absolute;
  top: 0; bottom: 24px;
  left: 50%;
  transform: translateX(-50%);
  width: 2px;
  background: #A67B5B;
  border-radius: 2px;
}
.bead {
  position: absolute;
  left: 50%;
  width: 52px;
  height: 28px;
  transform: translate(-50%, 0);
  will-change: transform;
  border-radius: 14px / 50%;
  background: radial-gradient(circle at 35% 35%, var(--primary), color-mix(in oklab, var(--primary) 60%, black));
  box-shadow:
    inset 0 -3px 6px rgba(0,0,0,0.3),
    inset 0 2px 4px rgba(255,255,255,0.4),
    0 2px 4px rgba(0,0,0,0.2);
  transition: transform 0.38s cubic-bezier(0.22, 1, 0.36, 1);
  z-index: 1;
}
.abacus-rod:nth-child(even) .bead {
  background: radial-gradient(circle at 35% 35%, var(--accent), color-mix(in oklab, var(--accent) 60%, black));
}
.abacus-rod:nth-child(3) .bead {
  background: radial-gradient(circle at 35% 35%, var(--accent-2), color-mix(in oklab, var(--accent-2) 60%, black));
}
.abacus-rod:nth-child(4) .bead {
  background: radial-gradient(circle at 35% 35%, var(--accent-4), color-mix(in oklab, var(--accent-4) 60%, black));
}

/* Heaven bead: at rest sits AT TOP, when active drops DOWN to divider.
   We animate transform (GPU-composited) instead of `top` (causes layout reflow). */
.bead.heaven { top: 6px; }
.bead.heaven.active { transform: translate(-50%, 36px); }

/* Earth beads: resting top = 248 - (4-idx)*32 (bottom stack);
   active offset = -38px (they rise to stick against the divider).
   Using transform instead of animating `top` keeps mobile buttery-smooth. */
.bead.earth {
  top: calc(248px - (4 - var(--idx)) * 32px);
}
.bead.earth.active {
  transform: translate(-50%, -38px);
}

.rod-label {
  position: absolute;
  bottom: 0;
  font-size: 11px;
  font-weight: 700;
  color: var(--ink-muted);
  letter-spacing: 0.05em;
}

/* Mental toggle */
.mental-toggle {
  display: inline-flex;
  align-items: center;
  gap: 12px;
  margin-top: 24px;
  cursor: pointer;
  user-select: none;
}
.mental-toggle input { display: none; }
.toggle-track {
  width: 44px;
  height: 24px;
  border-radius: 999px;
  background: var(--bg-alt);
  position: relative;
  transition: background 0.2s;
  flex-shrink: 0;
}
.demo-abacus.mental .toggle-track { background: rgba(255,255,255,0.15); }
.toggle-thumb {
  position: absolute;
  top: 3px; left: 3px;
  width: 18px; height: 18px;
  border-radius: 50%;
  background: white;
  transition: transform 0.25s cubic-bezier(0.34, 1.56, 0.64, 1);
  box-shadow: 0 1px 3px rgba(0,0,0,0.2);
}
.mental-toggle input:checked + .toggle-track {
  background: var(--accent-3);
}
.mental-toggle input:checked + .toggle-track .toggle-thumb {
  transform: translateX(20px);
}
.toggle-label { font-size: 14px; font-weight: 600; }

/* Controls */
.demo-controls {
  background: var(--card);
  border-radius: var(--radius-lg);
  padding: 32px;
  border: 1px solid var(--line);
  box-shadow: var(--shadow-md);
  display: flex;
  flex-direction: column;
}
.demo-controls-title {
  font-size: 12px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--ink-muted);
  margin-bottom: 14px;
}
.op-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 10px;
}
.op-btn {
  padding: 18px 16px;
  border-radius: 14px;
  font-family: var(--font-display);
  font-size: 24px;
  font-weight: 500;
  letter-spacing: -0.02em;
  background: var(--bg-alt);
  color: var(--ink);
  transition: transform 0.12s cubic-bezier(0.34, 1.56, 0.64, 1), box-shadow 0.15s, background 0.15s, color 0.15s;
  border: 2px solid transparent;
  -webkit-tap-highlight-color: transparent;
  touch-action: manipulation;
  user-select: none;
}
.op-btn:hover { transform: translateY(-2px); box-shadow: 0 8px 20px rgba(0,0,0,0.08); }
.op-btn:active { transform: scale(0.94); transition-duration: 0.06s; }
.op-btn.plus { color: var(--primary); background: color-mix(in oklab, var(--primary) 10%, var(--bg-alt)); }
.op-btn.plus:hover { background: var(--primary); color: white; }
.op-btn.plus:active { background: var(--primary); color: white; }
.op-btn.minus { color: var(--accent); background: color-mix(in oklab, var(--accent) 10%, var(--bg-alt)); }
.op-btn.minus:hover, .op-btn.minus:active { background: var(--accent); color: white; }
.op-btn.mul { color: var(--accent-2); background: color-mix(in oklab, var(--accent-2) 12%, var(--bg-alt)); }
.op-btn.mul:hover, .op-btn.mul:active { background: var(--accent-2); color: white; }
.op-btn.reset { color: var(--ink-muted); font-size: 28px; }
.op-btn.reset:hover, .op-btn.reset:active { background: var(--ink); color: white; }

.demo-history {
  flex: 1;
  min-height: 0;
}
.history-empty {
  color: var(--ink-muted);
  font-size: 14px;
  padding: 18px;
  background: var(--bg-alt);
  border-radius: 12px;
  text-align: center;
}
.history-list {
  display: flex;
  flex-direction: column;
  gap: 6px;
}
.history-row {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 12px 16px;
  background: var(--bg-alt);
  border-radius: 10px;
  font-family: var(--font-display);
  font-weight: 500;
  animation: history-in 0.4s cubic-bezier(0.34, 1.26, 0.64, 1);
}
@keyframes history-in {
  from { transform: translateX(-20px); opacity: 0; }
  to { transform: translateX(0); opacity: 1; }
}
.history-op {
  font-size: 18px;
  color: var(--primary);
  min-width: 50px;
}
.history-arrow {
  color: var(--ink-muted);
}
.history-result {
  font-size: 22px;
  color: var(--ink);
  margin-left: auto;
}

.demo-footnote {
  margin: 56px auto 0;
  max-width: 680px;
  display: flex;
  align-items: center;
  gap: 18px;
  padding: 22px 28px;
  background: linear-gradient(135deg,
    color-mix(in oklab, var(--accent-3) 22%, var(--card)) 0%,
    var(--card) 100%);
  border: 1px solid color-mix(in oklab, var(--accent-3) 45%, var(--line));
  border-radius: var(--radius-lg);
  box-shadow: 0 16px 40px color-mix(in oklab, var(--accent-3) 14%, transparent);
  position: relative;
}
.demo-footnote-icon {
  flex-shrink: 0;
  width: 56px;
  height: 56px;
  border-radius: 16px;
  background: var(--accent-3);
  display: grid;
  place-items: center;
  font-size: 28px;
  box-shadow: 0 6px 16px color-mix(in oklab, var(--accent-3) 50%, transparent);
}
.demo-footnote-body { flex: 1; min-width: 0; }
.demo-footnote-label {
  font-size: 11px;
  font-weight: 800;
  color: var(--primary);
  letter-spacing: 0.14em;
  text-transform: uppercase;
  margin-bottom: 6px;
}
.demo-footnote-text {
  font-size: 17px;
  color: var(--ink);
  font-weight: 500;
  line-height: 1.45;
}

@media (max-width: 960px) {
  .demo-grid { grid-template-columns: 1fr; }
  .digit-slot { width: 44px; height: 64px; }
  .digit > span { height: 64px; font-size: 48px; }
  .abacus-rod { height: 220px; }
  .bead { width: 42px; height: 22px; }
  .bead.earth { top: calc(196px - (4 - var(--idx)) * 26px); }
  /* Mobile deltas: earth rises 26px (active top was 66 + idx*26, inactive 196 - (4-idx)*26 → -26);
     heaven drops 28px (inactive top 6 → active top 34). */
  .bead.earth.active { transform: translate(-50%, -26px); }
  .bead.heaven.active { transform: translate(-50%, 28px); }
}

.demo-mobile-bar { display: none; }

@media (max-width: 600px) {
  .demo-abacus, .demo-controls { padding: 22px; }
  .op-btn { padding: 16px 12px; font-size: 22px; }
  .op-btn.reset { font-size: 24px; }

  /* Hide in-panel controls on mobile — the sticky bar below replaces them. */
  .demo-controls { display: none; }

  /* Floating action bar pinned to the bottom edge while the demo is in view. */
  .demo-mobile-bar {
    display: block;
    position: fixed;
    left: 0;
    right: 0;
    bottom: 0;
    padding: 10px 14px calc(12px + env(safe-area-inset-bottom));
    padding-left: max(14px, env(safe-area-inset-left));
    padding-right: max(14px, env(safe-area-inset-right));
    background: color-mix(in oklab, var(--card) 94%, transparent);
    backdrop-filter: blur(14px);
    -webkit-backdrop-filter: blur(14px);
    border-top: 1px solid var(--line);
    box-shadow: 0 -10px 28px -14px rgba(0,0,0,0.22);
    transform: translateY(calc(100% + 20px));
    transition: transform 0.32s cubic-bezier(.22,1,.36,1), opacity 0.2s;
    opacity: 0;
    z-index: 40;
    pointer-events: none;
  }
  .demo-mobile-bar.visible {
    transform: translateY(0);
    opacity: 1;
    pointer-events: auto;
  }
  .demo-mobile-bar .op-grid--mobile {
    grid-template-columns: repeat(4, 1fr);
    gap: 6px;
  }
  .demo-mobile-bar .op-btn {
    padding: 11px 4px;
    font-size: 16px;
    border-radius: 10px;
  }
  .demo-mobile-bar .op-btn.reset { font-size: 18px; }

  /* Reserve space so the bar never overlaps the "а вы знали?" block. */
  #demo { padding-bottom: calc(110px + env(safe-area-inset-bottom)); }

  .demo-footnote {
    margin-top: 36px;
    padding: 18px 20px;
    gap: 14px;
    border-radius: var(--radius-md);
  }
  .demo-footnote-icon {
    width: 46px;
    height: 46px;
    font-size: 22px;
    border-radius: 12px;
  }
  .demo-footnote-label { font-size: 10px; margin-bottom: 4px; }
  .demo-footnote-text { font-size: 15px; line-height: 1.4; }
}