.button--secondary,
.button--hint {
  border-color: var(--line-strong);
  background: var(--surface);
  color: var(--ink);
  box-shadow: none;
}

.button--secondary:not(:disabled):hover,
.button--hint:not(:disabled):hover {
  border-color: var(--ink);
  background: #f2f6f8;
}

.hint-control {
  display: grid;
  gap: var(--space-3);
}

.button--hint {
  min-inline-size: auto;
  min-block-size: 46px;
  padding-block: 0.55rem;
}

.calculation-hint {
  padding: var(--space-4);
  border: 1px solid var(--line-strong);
  border-inline-start: 5px solid var(--accent-strong);
  border-radius: 0 var(--radius) var(--radius) 0;
  background: #fffaf1;
}

.calculation-hint h2 {
  margin-block-end: var(--space-2);
  font-size: clamp(1.25rem, 4vw, 1.65rem);
}

.hint-label,
.hint-reminder {
  color: var(--muted);
  font-size: var(--text-small);
  font-weight: 750;
}

.hint-label {
  margin-block-end: 0.2rem;
  color: var(--accent-strong);
  letter-spacing: 0.05em;
}

.hint-reminder {
  margin-block: var(--space-3) 0;
}

.calculation-steps {
  display: grid;
  gap: 0.35rem;
  margin: 0;
  padding-inline-start: 1.35rem;
}

.quantity-comparison {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: var(--space-2);
  margin-block-start: var(--space-3);
}

.quantity-side {
  min-inline-size: 0;
  padding: var(--space-2);
  border-top: 1px solid var(--line);
}

.quantity-side > strong {
  display: block;
  margin-block-end: var(--space-2);
  font-size: var(--text-small);
}

.quantity-side__groups {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.quantity-group {
  display: grid;
  grid-template-columns: auto 1fr;
  gap: 0.4rem;
  align-items: center;
}

.quantity-number {
  font-size: var(--text-small);
  font-weight: 850;
}

.quantity-model {
  display: inline-flex;
  min-block-size: 36px;
  align-items: flex-end;
  gap: 3px;
}

.quantity-ten {
  inline-size: 9px;
  block-size: 34px;
  border: 2px solid var(--core);
  border-radius: 3px;
  background: #dfeeff;
}

.quantity-one {
  inline-size: 13px;
  block-size: 13px;
  border: 2px solid var(--support);
  border-radius: 3px;
  background: #dff4eb;
}

.quantity-zero {
  color: var(--muted);
  font-weight: 850;
}

.feedback {
  padding: var(--space-4);
  border: 2px solid;
  border-radius: var(--radius);
}

.feedback p {
  margin-block-end: 0;
}

.feedback--correct {
  border-color: var(--success);
  background: var(--success-soft);
}

.feedback--incorrect {
  border-color: var(--error);
  background: var(--error-soft);
}

.feedback__result {
  color: var(--success);
  font-size: 1.35rem;
  font-weight: 900;
}

.feedback--incorrect .feedback__result {
  color: var(--error);
}

.feedback__result span,
.summary-message span {
  display: inline-grid;
  inline-size: 1.7em;
  block-size: 1.7em;
  place-items: center;
  margin-inline-end: 0.3rem;
  border: 2px solid currentColor;
  border-radius: 50%;
  line-height: 1;
}

.feedback__correction {
  font-weight: 800;
}

.summary-screen {
  display: grid;
  gap: var(--space-5);
  max-inline-size: 720px;
  margin-inline: auto;
}

.summary-screen > .case-label,
.summary-screen > h1 {
  margin-block-end: calc(-1 * var(--space-4));
}

.total-result {
  display: flex;
  align-items: flex-end;
  justify-content: space-between;
  gap: var(--space-4);
  padding-block: var(--space-4);
  border-block: 2px solid var(--ink);
}

.total-result > span {
  font-weight: 850;
}

.total-result > strong {
  color: var(--accent-strong);
  font-size: clamp(3rem, 10vw, 5.5rem);
  line-height: 0.9;
  letter-spacing: -0.06em;
}

.total-result small {
  color: var(--muted);
  font-size: 0.36em;
  letter-spacing: 0;
}

.kind-results h2 {
  margin-block-end: var(--space-2);
}

.kind-results ul {
  margin: 0;
  padding: 0;
  border-top: 1px solid var(--line-strong);
  list-style: none;
}

.kind-results li {
  display: flex;
  min-block-size: 58px;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  border-bottom: 1px solid var(--line);
}

.kind-results strong {
  color: var(--ink);
  font-size: 1.15rem;
}

.summary-message {
  margin: 0;
  padding: var(--space-3) 0;
  color: var(--error);
  font-weight: 750;
}

.summary-message--perfect {
  color: var(--success);
}

.summary-actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.update-trigger {
  flex: 0 0 auto;
  min-block-size: 44px;
  padding: 0.55rem 0.9rem;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  background: var(--surface);
  box-shadow: none;
  cursor: pointer;
  color: var(--ink);
  font-size: var(--text-small);
  font-weight: 750;
}

.update-trigger__short {
  display: none;
}

body.dialog-open {
  overflow: hidden;
}

#update-history-dialog {
  inline-size: min(calc(100% - 24px), 680px);
  max-block-size: min(84vh, 720px);
  padding: 0;
  overflow: hidden;
  border: 0;
  border-radius: var(--radius);
  background: var(--surface);
  color: var(--ink);
  box-shadow: 0 24px 80px rgb(10 25 40 / 28%);
}

#update-history-dialog::backdrop {
  background: rgb(15 31 47 / 62%);
}

.dialog-panel {
  display: grid;
  max-block-size: min(84vh, 720px);
  grid-template-rows: auto minmax(0, 1fr);
}

.dialog-header {
  display: flex;
  align-items: flex-start;
  justify-content: space-between;
  gap: var(--space-3);
  padding: var(--space-4);
  border-bottom: 1px solid var(--line);
}

.dialog-header h1 {
  margin: 0;
  font-size: clamp(1.65rem, 5vw, 2.3rem);
}

.dialog-eyebrow {
  margin-block-end: 0.15rem;
  color: var(--accent-strong);
  font-size: var(--text-small);
  font-weight: 850;
}

.dialog-close {
  min-inline-size: 64px;
  min-block-size: 44px;
  padding: 0.5rem 0.75rem;
  border: 1px solid var(--line-strong);
  border-radius: 999px;
  background: var(--surface);
  cursor: pointer;
  font-size: var(--text-small);
  font-weight: 800;
}

.update-list {
  overflow-y: auto;
  overscroll-behavior: contain;
  padding: 0 var(--space-4) var(--space-4);
}

.update-entry {
  padding-block: var(--space-4);
}

.update-entry + .update-entry {
  border-top: 1px solid var(--line);
}

.update-entry time {
  color: var(--muted);
  font-size: var(--text-small);
  font-weight: 750;
}

.update-entry h2 {
  margin-block: 0.15rem var(--space-2);
}

.update-entry ul {
  margin: 0;
  padding-inline-start: 1.3rem;
}

@media (max-width: 520px) {
  .summary-actions .button {
    inline-size: 100%;
  }

  .dialog-header,
  .update-list {
    padding-inline: var(--space-3);
  }

  .update-trigger {
    min-inline-size: 52px;
    padding-inline: 0.55rem;
  }

  .update-trigger__full {
    display: none;
  }

  .update-trigger__short {
    display: inline;
  }

  .calculation-hint {
    padding: var(--space-2);
  }

  .quantity-comparison {
    gap: var(--space-1);
    margin-block-start: var(--space-2);
  }

  .quantity-side {
    padding: var(--space-1);
  }

  .quantity-side > strong {
    margin-block-end: var(--space-1);
  }

  .quantity-side__groups {
    gap: var(--space-1);
  }

  .hint-reminder {
    margin-block-start: var(--space-2);
  }
}