.rng-diagram {
  --rng-surface: #f7f9fc;
  --rng-border: #cbd5e1;
  --rng-text: #203047;
  --rng-muted: #64748b;
  --rng-iid-bg: #e7f6f3;
  --rng-iid-border: #16877b;
  --rng-qmc-bg: #fff0d8;
  --rng-qmc-border: #c77700;
  --rng-classic-bg: #e8f1fb;
  --rng-classic-border: #4f7cac;

  max-width: 46rem;
  margin: 1.75rem auto;
  padding: 1.25rem;
  color: var(--rng-text);
  background: var(--rng-surface);
  border: 1px solid var(--rng-border);
  border-radius: 0.9rem;
  box-shadow: 0 0.55rem 1.4rem rgb(15 23 42 / 8%);
}

[theme="dark"] .rng-diagram {
  --rng-surface: #20252d;
  --rng-border: #46505e;
  --rng-text: #edf2f7;
  --rng-muted: #b8c1cc;
  --rng-iid-bg: #173e3a;
  --rng-iid-border: #4dc6b6;
  --rng-qmc-bg: #4c3517;
  --rng-qmc-border: #e5a33a;
  --rng-classic-bg: #253a52;
  --rng-classic-border: #78a9d4;
}

.rng-diagram__node,
.rng-diagram__criterion,
.rng-diagram__answer {
  box-sizing: border-box;
  border: 1.5px solid var(--rng-border);
  border-radius: 0.7rem;
  text-align: center;
}

.rng-diagram__node,
.rng-diagram__answer {
  padding: 0.65rem 0.9rem;
  font-weight: 700;
}

.rng-diagram__arrow {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 0.55rem;
  min-height: 2.4rem;
  color: var(--rng-muted);
}

.rng-diagram__arrow-symbol {
  font-size: 1.35rem;
  line-height: 1;
}

.rng-decision__question {
  width: fit-content;
  min-width: 11rem;
  margin: 0 auto;
  background: var(--rng-classic-bg);
  border-color: var(--rng-classic-border);
}

.rng-decision__branches {
  position: relative;
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 1.25rem;
  padding-top: 2.15rem;
}

.rng-decision__branches::before {
  position: absolute;
  top: 0.8rem;
  right: 25%;
  left: 25%;
  border-top: 1.5px solid var(--rng-border);
  content: "";
}

.rng-decision__branch {
  position: relative;
  display: flex;
  flex-direction: column;
  align-items: stretch;
}

.rng-decision__branch::before {
  position: absolute;
  top: -1.35rem;
  left: 50%;
  height: 1.35rem;
  border-left: 1.5px solid var(--rng-border);
  content: "";
}

.rng-diagram__criterion {
  display: flex;
  flex: 1;
  align-items: center;
  justify-content: center;
  min-height: 6.2rem;
  padding: 0.85rem;
  line-height: 1.5;
}

.rng-decision__branch--iid .rng-diagram__criterion,
.rng-decision__branch--iid .rng-diagram__answer {
  background: var(--rng-iid-bg);
  border-color: var(--rng-iid-border);
}

.rng-decision__branch--qmc .rng-diagram__criterion,
.rng-decision__branch--qmc .rng-diagram__answer {
  background: var(--rng-qmc-bg);
  border-color: var(--rng-qmc-border);
}

.rng-evolution {
  display: flex;
  max-width: 34rem;
  flex-direction: column;
  align-items: center;
}

.rng-evolution .rng-diagram__node {
  width: min(100%, 24rem);
  background: var(--rng-classic-bg);
  border-color: var(--rng-classic-border);
}

.rng-evolution .rng-diagram__node--modern {
  background: var(--rng-iid-bg);
  border-color: var(--rng-iid-border);
}

.rng-evolution .rng-diagram__node--highlight {
  background: var(--rng-qmc-bg);
  border-color: var(--rng-qmc-border);
}

.rng-evolution .rng-diagram__arrow-label {
  font-size: 0.9rem;
  font-style: italic;
}

@media (max-width: 620px) {
  .rng-diagram {
    padding: 1rem;
  }

  .rng-decision__branches {
    grid-template-columns: 1fr;
    gap: 1rem;
    padding-top: 1rem;
  }

  .rng-decision__branches::before,
  .rng-decision__branch::before {
    display: none;
  }

  .rng-decision__branch + .rng-decision__branch {
    padding-top: 1rem;
    border-top: 1px dashed var(--rng-border);
  }

  .rng-diagram__criterion {
    min-height: auto;
  }
}