.rekenrek-dialog {
  width: min(950px, calc(100% - 24px));
  max-height: min(94svh, 720px);
  margin: auto;
  padding: 0;
  overflow: auto;
  border: 0;
  border-radius: 22px;
  color: var(--ink);
  background: #fff;
  box-shadow: 0 24px 70px rgba(16, 41, 74, .3);
}
.rekenrek-dialog::backdrop { background: rgba(10, 31, 59, .48); }
.rekenrek-panel { display: grid; gap: 13px; padding: 20px; }
.rekenrek-header { display: flex; align-items: center; justify-content: space-between; gap: 14px; }
.rekenrek-header h2 {
  margin: 0;
  color: var(--navy);
  font-family: Georgia, "Times New Roman", serif;
  font-size: clamp(1.5rem, 4vw, 2rem);
}
.rekenrek-close {
  width: 44px;
  height: 44px;
  flex: none;
  display: grid;
  place-items: center;
  padding: 0;
  border: 1px solid var(--line);
  border-radius: 12px;
  color: var(--navy);
  background: #fff;
  font-size: 1.8rem;
  line-height: 1;
  cursor: pointer;
}
.rekenrek-close:focus-visible,
.rekenrek-bead:focus-visible {
  outline: 3px solid color-mix(in srgb, var(--blue) 35%, transparent);
  outline-offset: 3px;
}
.rekenrek-equation {
  min-height: 58px;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 10px;
  padding: 9px 14px;
  border-radius: 14px;
  color: var(--ink);
  background: #f3f7fc;
  font-family: "DejaVu Sans Mono", Consolas, monospace;
  font-size: clamp(1.35rem, 5vw, 2rem);
  font-weight: 850;
}
.rekenrek-equation-value { display: grid; place-items: center; line-height: 1; }
.rekenrek-equation-sign { color: var(--navy); }
.rekenrek-equation-question { color: var(--orange); }
.rekenrek-carry-label {
  margin-top: 3px;
  color: var(--violet);
  font-family: "Segoe UI", system-ui, sans-serif;
  font-size: .5em;
  line-height: 1;
}
.rekenrek-description {
  margin: 0;
  color: var(--ink);
  font-size: clamp(1rem, 2.6vw, 1.18rem);
  font-weight: 750;
  line-height: 1.4;
  text-align: center;
}
.rekenrek-rank-note {
  margin: -5px 0 0;
  color: var(--muted);
  font-size: .9rem;
  font-weight: 650;
  line-height: 1.35;
  text-align: center;
}
.rekenrek-frame {
  width: min(820px, calc(100% - 60px));
  justify-self: center;
  display: grid;
  gap: 0;
  padding: 0;
  border-right: 30px solid #9b6a36;
  border-left: 30px solid #9b6a36;
  background: #fbfcfe;
  box-shadow: 0 4px 12px rgba(16, 41, 74, .18);
}
.rekenrek-row {
  width: 100%;
  height: 56px;
  min-width: 0;
  position: relative;
  touch-action: none;
}
.rekenrek-rod {
  position: absolute;
  z-index: 1;
  top: 50%;
  right: 0;
  left: 0;
  height: 4px;
  transform: translateY(-50%);
  background: #66717e;
}
.rekenrek-bead {
  position: absolute;
  z-index: 2;
  top: 50%;
  width: clamp(24px, calc((100vw - 80px) / 10), 38px);
  height: clamp(24px, calc((100vw - 80px) / 10), 38px);
  padding: 0;
  transform: translateY(-50%);
  border: 0;
  border-radius: 50%;
  box-shadow: inset -3px -3px 6px rgba(16, 41, 74, .28), 2px 2px 5px rgba(16, 41, 74, .25);
  cursor: grab;
  touch-action: none;
  transition: left .22s ease-out;
}
.rekenrek-bead:active,
.rekenrek-bead.is-moving { cursor: grabbing; }
.rekenrek-bead.is-red {
  background: radial-gradient(circle at 30% 30%, #ff5f5f, #a00);
}
.rekenrek-bead.is-white {
  border: 1px solid #c7cdd5;
  background: radial-gradient(circle at 30% 30%, #fff, #bbb);
}
.rekenrek-manipulation-hint {
  margin: -2px 0 0;
  color: var(--muted);
  font-size: .86rem;
  font-weight: 700;
  text-align: center;
}
.rekenrek-panel .sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}
.rekenrek-footer {
  display: flex;
  justify-content: flex-end;
  flex-wrap: wrap;
  gap: 10px;
  padding-top: 5px;
  border-top: 1px solid var(--line);
}

@media (max-width: 640px) {
  .rekenrek-frame {
    width: min(820px, calc(100% - 18px));
    border-right-width: 9px;
    border-left-width: 9px;
  }
  .rekenrek-row { height: 48px; }
}

@media (max-width: 520px) {
  .rekenrek-dialog { width: calc(100% - 12px); border-radius: 18px; }
  .rekenrek-panel { gap: 10px; padding: 13px 11px; }
  .rekenrek-equation { min-height: 50px; gap: 7px; padding-inline: 8px; }
  .rekenrek-rank-note { font-size: .78rem; }
  .rekenrek-footer { display: grid; grid-template-columns: 1fr; }
  .rekenrek-footer .button { width: 100%; }
}

@media (prefers-reduced-motion: reduce) {
  .rekenrek-bead { transition: none !important; }
}