/* =========================================================
   ДОБРЫНЯ-ЭРУДИТ — ЦЕПОЧКА ДЕЙСТВИЙ
   ========================================================= */

.chain-intro {
  max-width: 760px;
  margin: 16px auto 0;
  color: #476786;
  font-size: clamp(16px, 2vw, 19px);
  line-height: 1.55;
}

.chain-settings-grid {
  max-width: 900px;
  margin: 0 auto;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 16px;
}

.chain-settings-grid .setting-card--wide {
  grid-column: 1 / -1;
}

.chain-settings-footer {
  max-width: 900px;
  margin-right: auto;
  margin-left: auto;
}

.chain-level-picker {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 12px;
}

.chain-level-card {
  min-height: 100px;
  padding: 16px;
  border: 1px solid rgba(47,141,246,.22);
  border-radius: 20px;
  background: #fff;
  color: #285f9c;
  box-shadow: 0 8px 18px rgba(37,91,143,.09);
  cursor: pointer;
  text-align: center;
  transition: transform .18s ease, border-color .18s ease, box-shadow .18s ease, background .18s ease;
}

.chain-level-card:hover {
  transform: translateY(-2px);
  border-color: rgba(47,141,246,.46);
  box-shadow: 0 12px 24px rgba(37,91,143,.13);
}

.chain-level-card.is-selected {
  border-color: rgba(255,184,77,.85);
  background: linear-gradient(145deg, #fff9d9, #fff2c5);
  box-shadow: 0 10px 24px rgba(255,184,77,.2);
}

.chain-level-card strong {
  display: block;
  font-family: "Comfortaa", sans-serif;
  font-size: 22px;
}

.chain-level-card span {
  display: block;
  margin-top: 6px;
  color: #698198;
  font-size: 13px;
  font-weight: 700;
}

.chain-length-picker {
  grid-template-columns: repeat(3, 1fr);
}

.chain-exercise-card {
  max-width: 900px;
  min-height: 650px;
  margin: 0 auto;
}

.chain-board {
  width: min(430px, 100%);
  margin: 12px auto 6px;
  padding: 22px 18px 10px;
  display: grid;
  justify-items: center;
}

.chain-start,
.chain-step {
  position: relative;
  width: 138px;
  min-height: 92px;
  display: grid;
  place-items: start center;
}

.chain-start::after,
.chain-step::after {
  content: "";
  position: absolute;
  top: 72px;
  width: 3px;
  height: 30px;
  border-radius: 999px;
  background: rgba(58,112,162,.22);
}

.chain-step:last-child::after {
  display: none;
}

.chain-triangle {
  width: 132px;
  height: 82px;
  display: grid;
  place-items: start center;
  padding-top: 12px;
  clip-path: polygon(0 0, 100% 0, 50% 100%);
  background: linear-gradient(145deg, #9b59a7, #703d86);
  filter: drop-shadow(0 7px 9px rgba(64,46,95,.12));
}

.chain-start .chain-triangle {
  background: linear-gradient(145deg, #ffc928, #efa500);
}

.chain-bubble {
  width: 64px;
  height: 64px;
  display: grid;
  place-items: center;
  border: 3px solid rgba(255,255,255,.82);
  border-radius: 50%;
  background: linear-gradient(145deg, #fff, #edf1f4);
  color: #24384b;
  box-shadow: inset 0 2px 5px rgba(255,255,255,.85), 0 5px 12px rgba(32,64,91,.13);
  font-family: "Comfortaa", "Onest", sans-serif;
  font-size: 22px;
  font-weight: 700;
  white-space: nowrap;
}

.chain-start .chain-bubble {
  font-size: 23px;
}

.chain-note {
  width: min(660px, 100%);
  margin: 12px auto 0;
  color: #7890a5;
  font-size: 14px;
  font-weight: 600;
  text-align: center;
}

.chain-answer-area,
.chain-hint {
  margin-right: auto;
  margin-left: auto;
}

.chain-input {
  display: grid;
  grid-template-columns: auto minmax(130px, 260px) auto;
  align-items: center;
  justify-content: center;
  gap: 12px;
}

.chain-input label {
  color: #456987;
  font-size: 18px;
  font-weight: 800;
}

.chain-input input {
  min-width: 0;
  height: 68px;
  border: 2px solid rgba(47,141,246,.28);
  border-radius: 19px;
  padding: 0 18px;
  color: #1f5b96;
  background: #fff;
  font-family: "Comfortaa", sans-serif;
  font-size: 32px;
  font-weight: 700;
  text-align: center;
  outline: none;
}

.chain-input input:focus {
  border-color: var(--blue);
  box-shadow: 0 0 0 5px rgba(47,141,246,.1);
}

.chain-input input.is-wrong {
  border-color: #f1a4af;
  background: #fff3f5;
  animation: trainer-shake .34s ease;
}

.chain-input input.is-correct {
  border-color: #71d5a5;
  background: #effff5;
}

.chain-solution {
  width: min(720px, 100%);
  margin: 18px auto 0;
  padding: 18px 20px;
  border: 1px solid rgba(126,217,87,.34);
  border-radius: 20px;
  background: linear-gradient(145deg, #f7fff3, #eaffdf);
  color: #315b3d;
  box-shadow: 0 9px 20px rgba(77,145,65,.08);
}

.chain-solution h3 {
  margin: 0 0 10px;
  color: #367449;
  font-family: "Comfortaa", sans-serif;
  font-size: 19px;
}

.chain-solution-row {
  margin: 7px 0 0;
  color: #244d32;
  font-size: 17px;
  font-weight: 700;
}

.chain-final {
  margin: 12px 0 0;
  font-weight: 800;
}

.chain-next-wrap {
  margin-top: 18px;
  text-align: center;
}

@media (max-width: 760px) {
  .chain-settings-grid {
    grid-template-columns: 1fr;
  }

  .chain-settings-grid .setting-card--wide {
    grid-column: auto;
  }

  .chain-level-picker {
    grid-template-columns: 1fr;
  }

  .chain-input {
    grid-template-columns: 1fr;
  }

  .chain-input label {
    text-align: center;
  }

  .chain-input .trainer-btn {
    width: 100%;
  }
}