.calculator-shell {
  --calc-border: #d9e2ec;
  --calc-surface: #ffffff;
  --calc-surface-alt: #f6f9fc;
  --calc-text: #17324d;
  --calc-muted: #6b7c93;
  --calc-accent: #1f6feb;
  --calc-accent-soft: #e9f2ff;
  --calc-success-bg: #eefbf3;
  --calc-success-text: #1f5132;
  --calc-danger-bg: #fff1f1;
  --calc-danger-text: #a61b1b;
  max-width: 760px;
  margin: 0 auto;
  border: 1px solid var(--calc-border);
  border-radius: 20px;
  background: linear-gradient(180deg, var(--calc-surface-alt) 0%, var(--calc-surface) 100%);
  box-shadow: 0 18px 45px rgba(23, 50, 77, 0.08);
  color: var(--calc-text);
  overflow: hidden;
}

.calculator-header {
  padding: 28px 28px 16px;
}

.calculator-title {
  margin: 0 0 10px;
  font-size: 30px;
  line-height: 1.2;
}

.calculator-description {
  margin: 0;
  font-size: 15px;
  line-height: 1.65;
  color: var(--calc-muted);
}

.calculator-body {
  padding: 0 28px 28px;
}

.calculator-form {
  display: grid;
  gap: 18px;
}

.form-row {
  display: grid;
  grid-template-columns: minmax(220px, 1.3fr) minmax(180px, 0.8fr);
  gap: 12px 20px;
  align-items: center;
  padding: 18px 20px;
  border-radius: 16px;
  background: rgba(255, 255, 255, 0.88);
  border: 1px solid rgba(217, 226, 236, 0.95);
}

.form-row label {
  font-weight: 600;
  font-size: 15px;
  line-height: 1.45;
}

.field-with-unit {
  display: flex;
  align-items: center;
  gap: 10px;
}

.field-with-unit input {
  width: 100%;
  min-width: 0;
}

.field-unit {
  flex: 0 0 auto;
  min-width: 56px;
  color: var(--calc-muted);
  font-size: 14px;
  text-align: left;
}

.field-note {
  grid-column: 1 / -1;
  color: var(--calc-muted);
  font-size: 13px;
  line-height: 1.5;
}

.calculator-shell input[type="number"] {
  height: 46px;
  padding: 0 14px;
  border: 1px solid var(--calc-border);
  border-radius: 12px;
  background: #fff;
  color: var(--calc-text);
  font-size: 15px;
  transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.calculator-shell input[type="number"]:focus,
.calculator-shell input[type="range"]:focus {
  outline: none;
}

.calculator-shell input[type="number"]:focus {
  border-color: var(--calc-accent);
  box-shadow: 0 0 0 4px rgba(31, 111, 235, 0.12);
}

.calculator-shell input[type="range"] {
  grid-column: 1 / -1;
  width: 100%;
  accent-color: var(--calc-accent);
}

.ratio-display {
  grid-column: 1 / -1;
  display: grid;
  grid-template-columns: auto 1fr auto;
  gap: 12px;
  align-items: center;
  padding: 14px 16px;
  border-radius: 14px;
  background: var(--calc-accent-soft);
}

.ratio-label-start,
.ratio-label-end {
  font-size: 13px;
  color: var(--calc-muted);
}

.ratio-summary {
  text-align: center;
}

.ratio-value {
  display: inline-block;
  font-size: 22px;
  font-weight: 700;
  line-height: 1.2;
}

.ratio-note {
  margin-top: 4px;
  font-size: 13px;
  color: var(--calc-muted);
}

.form-actions {
  display: flex;
  justify-content: flex-start;
}

.form-actions button {
  min-width: 220px;
  min-height: 50px;
  padding: 0 24px;
  border: 0;
  background-color: var(--color-primary);
  color: #fff;
  font-size: 14px;
  font-weight: 700;
  letter-spacing: 0.02em;
  cursor: pointer;

}

.form-actions button:hover {
 
  background-color: var(--color-primary-hover);
    border-color: var(--color-primary-hover);
    color: var(--colors-foregrounds-content-inverted);
}

.calculator-result {
  margin-top: 20px;
}

.result-state {
  padding: 20px 22px;
  border-radius: 16px;
  font-size: 15px;
  line-height: 1.7;
}

.result-state + .result-state {
  margin-top: 14px;
}

.result-state-primary,
.result-state-secondary {
  background: var(--calc-success-bg);
  color: var(--calc-success-text);
}

.result-state-error {
  background: var(--calc-danger-bg);
  color: var(--calc-danger-text);
}

.result-heading {
  margin: 0 0 8px;
  font-size: 20px;
  line-height: 1.3;
}

.result-summary {
  margin: 0;
}

.calculator-shell a {
  color: var(--calc-accent);
  text-decoration: underline;
  text-underline-offset: 2px;
}

.calculator-shell a:hover {
  text-decoration: none;
}

.calculator-shell strong {
  font-weight: 700;
}

.is-hidden {
  display: none;
}

@media (max-width: 767px) {
  .calculator-shell {
    border-radius: 16px;
  }

  .calculator-header,
  .calculator-body {
    padding-left: 18px;
    padding-right: 18px;
  }

  .calculator-title {
    font-size: 24px;
  }

  .form-row {
    grid-template-columns: 1fr;
    padding: 16px;
  }

  .ratio-display {
    grid-template-columns: 1fr;
    text-align: center;
  }

  .field-unit {
    min-width: 48px;
  }

  .form-actions button {
    width: 100%;
  }
}