:root {
  --slate-50: #f8fafc;
  --slate-100: #f1f5f9;
  --slate-200: #e2e8f0;
  --slate-300: #cbd5e1;
  --slate-500: #64748b;
  --slate-600: #475569;
  --slate-700: #334155;
  --slate-800: #1e293b;
  --sky-100: #e0f2fe;
  --sky-200: #bae6fd;
  --sky-500: #0ea5e9;
  --sky-600: #0284c7;
  --sky-700: #0369a1;
  --sky-800: #075985;
  --white: #ffffff;
  --blue-50: #eff6ff;
  --blue-400: #60a5fa;
  --blue-800: #1e40af;
}

.pregnancy-calculator-container {
  font-family: sans-serif;
  color: var(--slate-600);
  max-width: 1290px;
  margin-left: auto;
  margin-right: auto;
}

.calculator-wrapper {
  background-color: var(--white);
  border-radius: 1rem; /* 16px */
  box-shadow: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
  padding: 1rem;
}

.calculator-header {
  text-align: center;
  margin-bottom: 2rem;
}

.calculator-title {
  font-size: 1.875rem; /* 30px */
  line-height: 2.25rem; /* 36px */
  font-weight: 700;
  color: var(--slate-800);
}

.calculator-subtitle {
  margin-top: 0.5rem;
  font-size: 1.125rem; /* 18px */
  line-height: 1.75rem; /* 28px */
  color: var(--slate-600);
}

.form-wrapper {
  max-width: 42rem; /* 672px */
  margin-left: auto;
  margin-right: auto;
}

.form-container {
  background-color: var(--slate-50);
  padding: 1rem;
  border-radius: 0.75rem; /* 12px */
  border: 1px solid var(--slate-200);
}

.form-title {
  font-weight: 600;
  font-size: 1.25rem; /* 20px */
  color: var(--slate-700);
  margin-bottom: 1.25rem;
}

.form-content {
  display: grid;
  gap: 1.5rem;
}

.form-label {
  display: block;
  font-size: 0.875rem; /* 14px */
  line-height: 1.25rem; /* 20px */
  font-weight: 500;
  color: var(--slate-600);
  margin-bottom: 0.5rem;
}

.method-switcher {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.5rem;
  border-radius: 0.5rem; /* 8px */
  background-color: var(--slate-200);
  padding: 0.25rem;
}

.method-button {
  padding: 0.5rem 1rem;
  font-size: 0.875rem; /* 14px */
  font-weight: 600;
  border-radius: 0.375rem; /* 6px */
  transition: color 0.2s, background-color 0.2s;
  border: none;
  cursor: pointer;
  background-color: transparent;
  color: var(--slate-600);
}

.method-button:hover {
    background-color: rgba(203, 213, 225, 0.5); /* slate-300 with 50% opacity */
}

.method-button.active {
  background-color: var(--white);
  color: var(--sky-700);
  box-shadow: 0 1px 3px 0 rgb(0 0 0 / 0.1), 0 1px 2px -1px rgb(0 0 0 / 0.1);
}

.date-input {
  width: 100%;
  padding: 0.5rem 0.75rem;
  border: 1px solid var(--slate-300);
  border-radius: 0.5rem; /* 8px */
  box-shadow: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  transition: all 0.2s;
}

.date-input:focus {
  outline: 2px solid transparent;
  outline-offset: 2px;
  box-shadow: 0 0 0 2px var(--sky-500);
  border-color: var(--sky-500);
}

.cycle-length-control {
  display: flex;
  align-items: center;
  gap: 0.75rem;
}

.range-slider {
  width: 100%;
  height: 0.5rem;
  background-color: var(--slate-200);
  border-radius: 9999px;
  -webkit-appearance: none;
  appearance: none;
  cursor: pointer;
  accent-color: var(--sky-600);
}
.range-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 1.25rem;
  height: 1.25rem;
  background: var(--sky-600);
  border-radius: 50%;
  border: 3px solid var(--white);
  box-shadow: 0 1px 3px rgba(0,0,0,0.2);
  cursor: pointer;
}
.range-slider::-moz-range-thumb {
  width: 1.25rem;
  height: 1.25rem;
  background: var(--sky-600);
  border-radius: 50%;
  border: 3px solid var(--white);
  box-shadow: 0 1px 3px rgba(0,0,0,0.2);
  cursor: pointer;
}


.range-value {
  font-weight: 600;
  color: var(--sky-700);
  background-color: var(--sky-100);
  border-radius: 0.375rem;
  padding: 0.25rem 0.75rem;
  font-size: 0.875rem;
  width: 5rem;
  text-align: center;
}

.results-wrapper {
  margin-top: 3rem;
}

.results-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 1rem;
}

.results-title {
  font-weight: 700;
  font-size: 1.25rem; /* 20px */
  color: var(--slate-700);
}

.results-actions {
  display: flex;
  gap: 0.5rem;
}

.action-button {
  padding: 0.5rem;
  color: var(--slate-500);
  border-radius: 9999px;
  transition: all 0.2s;
  border: none;
  background-color: transparent;
  cursor: pointer;
}

.action-button:hover {
  background-color: var(--slate-200);
  color: var(--slate-700);
}

.results-content {
  display: grid;
  gap: 1rem;
}

.due-date-highlight {
  background-color: var(--sky-600);
  color: var(--white);
  padding: 1.5rem;
  border-radius: 0.75rem;
  text-align: center;
  box-shadow: 0 10px 15px -3px rgb(0 0 0 / 0.1), 0 4px 6px -4px rgb(0 0 0 / 0.1);
}

.due-date-label {
  font-size: 0.875rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--sky-200);
}

.due-date-value {
  font-size: 1.875rem;
  font-weight: 700;
  margin-top: 0.25rem;
}

.due-date-subtext {
  font-size: 0.875rem;
  color: var(--sky-200);
  margin-top: 0.5rem;
}

.results-grid {
  display: grid;
  gap: 1rem;
}

.result-item {
  background-color: var(--slate-50);
  padding: 1rem;
  border-radius: 0.5rem;
}

.result-label {
  font-size: 0.875rem;
  color: var(--slate-500);
  margin-bottom: 0.25rem;
}

.result-value {
  font-size: 1.125rem;
  font-weight: 700;
  color: var(--sky-800);
}

.future-notice {
  background-color: var(--blue-50);
  border-left: 4px solid var(--blue-400);
  padding: 1rem;
  color: var(--blue-800);
}

.timeline-container {
  padding-top: 2rem;
}

.timeline-title {
  font-size: 1.125rem;
  font-weight: 600;
  color: var(--slate-700);
  margin-bottom: 1rem;
}

.timeline-track {
  position: relative;
  height: 0.5rem;
  background-color: var(--slate-200);
  border-radius: 9999px;
  width: 100%;
}

.timeline-progress-bar {
  position: absolute;
  height: 0.5rem;
  background: linear-gradient(to right, var(--sky-500), var(--sky-600));
  border-radius: 9999px;
}

.timeline-marker-today {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
}

.marker-tooltip {
    position: relative;
    bottom: 1.7rem;
    left: 50%;
    transform: translateX(-50%);
    white-space: nowrap;
}

.tooltip-text {
  font-size: 0.75rem;
  background-color: var(--sky-600);
  color: var(--white);
  font-weight: 700;
  padding: 0.25rem 0.5rem;
  border-radius: 0.375rem;
}

.tooltip-arrow {
  width: 0;
  height: 0;
  border-left: 4px solid transparent;
  border-right: 4px solid transparent;
  border-top: 4px solid var(--sky-600);
  margin: 0.1rem auto 0;
}

.marker-dot {
  width: 1rem;
  height: 1rem;
  background-color: var(--white);
  border: 2px solid var(--sky-600);
  border-radius: 50%;
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
}

.timeline-marker-event {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  height: 1rem;
  width: 2px;
  background-color: var(--slate-500);
}

.marker-label {
  position: absolute;
  top: -1.75rem;
  left: 50%;
  transform: translateX(-50%);
  font-size: 0.75rem;
  color: var(--slate-500);
  white-space: nowrap;
}

.timeline-labels {
  display: flex;
  justify-content: space-between;
  font-size: 0.75rem;
  color: var(--slate-500);
  margin-top: 0.5rem;
}

.initial-message {
  display: flex;
  align-items: center;
  justify-content: center;
  background-color: var(--slate-100);
  border-radius: 0.75rem;
  padding: 2rem;
  text-align: center;
  margin-top: 3rem;
  color: var(--slate-500);
}

/* Responsive Styles */
@media (min-width: 640px) {
  .calculator-wrapper {
    padding: 2rem;
  }
  .calculator-title {
    font-size: 2.25rem; /* 36px */
    line-height: 2.5rem; /* 40px */
  }
  .results-grid {
    grid-template-columns: 1fr 1fr;
  }
}

@media (min-width: 1024px) {
  .calculator-wrapper {
    padding: 3rem;
  }
}

/* Print Styles */
@media print {
  body * {
    visibility: hidden;
  }
  #print-section, #print-section * {
    visibility: visible;
  }
  #print-section {
    position: absolute;
    left: 0;
    top: 0;
    width: 100%;
    box-shadow: none;
    border: none;
  }
  .no-print {
    display: none;
  }
}