:root {
  --primary-color: #007bff;
  --primary-light: #e6f2ff;
  --secondary-color: #6c757d;
  --background-color: #ffffff;
  --surface-color: #f8f9fa;
  --border-color: #dee2e6;
  --text-color: #343a40;
  --text-muted-color: #6c757d;
  --success-color: #28a745;
  --font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

.audiobook-calculator-container {
  font-family: var(--font-family);
  background-color: var(--background-color);
  color: var(--text-color);
  padding: 2rem;
  max-width: 800px;
  margin: 2rem auto;
  border-radius: 12px;
  box-shadow: 0 8px 30px rgba(0, 0, 0, 0.08);
  border: 1px solid var(--border-color);
}

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

.calculator-header h2 {
  font-size: 1.8rem;
  margin: 0 0 0.5rem 0;
  color: var(--text-color);
}

.calculator-header p {
  font-size: 1rem;
  color: var(--text-muted-color);
  margin: 0;
}

.calculator-form fieldset {
  border: 1px solid var(--border-color);
  border-radius: 8px;
  padding: 1.5rem;
  margin-bottom: 1.5rem;
}

.calculator-form legend {
  font-size: 1.1rem;
  font-weight: 600;
  padding: 0 0.5rem;
  color: var(--primary-color);
}

.form-row {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 1.5rem;
}

.form-group {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.form-group label {
  font-weight: 500;
  font-size: 0.9rem;
}

.form-group input[type="number"],
.form-group input[type="date"] {
  width: 100%;
  padding: 0.75rem;
  border: 1px solid var(--border-color);
  border-radius: 6px;
  font-size: 1rem;
  transition: border-color 0.2s, box-shadow 0.2s;
}

.form-group input:focus {
  outline: none;
  border-color: var(--primary-color);
  box-shadow: 0 0 0 3px var(--primary-light);
}

.slider-group .slider-wrapper {
  display: flex;
  align-items: center;
  gap: 1rem;
}

.slider-group input[type="range"] {
  -webkit-appearance: none;
  appearance: none;
  width: 100%;
  height: 8px;
  background: var(--border-color);
  border-radius: 5px;
  outline: none;
}

.slider-group input[type="range"]::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 20px;
  height: 20px;
  background: var(--primary-color);
  cursor: pointer;
  border-radius: 50%;
  border: 2px solid white;
}

.slider-group input[type="range"]::-moz-range-thumb {
  width: 20px;
  height: 20px;
  background: var(--primary-color);
  cursor: pointer;
  border-radius: 50%;
  border: 2px solid white;
}

.slider-group output {
  font-weight: 600;
  color: var(--primary-color);
  background-color: var(--primary-light);
  padding: 0.25rem 0.75rem;
  border-radius: 1rem;
  min-width: 45px;
  text-align: center;
}

.checkbox-group {
  display: flex;
  flex-wrap: wrap;
  gap: 0.75rem;
}

.checkbox-group label {
  display: flex;
  align-items: center;
  cursor: pointer;
  border: 1px solid var(--border-color);
  padding: 0.5rem 1rem;
  border-radius: 2rem;
  transition: all 0.2s;
}

.checkbox-group input[type="checkbox"] {
  display: none;
}

.checkbox-group label:has(input:checked) {
  background-color: var(--primary-light);
  border-color: var(--primary-color);
  color: var(--primary-color);
  font-weight: 600;
}

.checkbox-group label:hover {
    background-color: #f1f3f5;
}

.input-with-suffix {
  display: flex;
  align-items: center;
}

.input-with-suffix input {
  border-top-right-radius: 0;
  border-bottom-right-radius: 0;
  border-right: none;
}

.input-with-suffix span {
  padding: 0.75rem;
  background-color: var(--surface-color);
  border: 1px solid var(--border-color);
  border-left: none;
  border-top-right-radius: 6px;
  border-bottom-right-radius: 6px;
}

.tooltip-trigger {
  display: inline-block;
  cursor: help;
  position: relative;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background-color: var(--secondary-color);
  color: white;
  text-align: center;
  font-size: 12px;
  line-height: 16px;
  font-weight: bold;
}

.tooltip-trigger::after {
  content: attr(data-tooltip);
  position: absolute;
  bottom: 125%;
  left: 50%;
  transform: translateX(-50%);
  background-color: #333;
  color: #fff;
  padding: 0.5rem 0.75rem;
  border-radius: 4px;
  font-size: 0.8rem;
  white-space: nowrap;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.2s, visibility 0.2s;
  z-index: 10;
}

.tooltip-trigger:hover::after {
  opacity: 1;
  visibility: visible;
}


.calculate-btn {
  width: 100%;
  padding: 1rem;
  font-size: 1.1rem;
  font-weight: 600;
  color: white;
  background-color: var(--primary-color);
  border: none;
  border-radius: 8px;
  cursor: pointer;
  transition: background-color 0.2s, transform 0.1s;
}

.calculate-btn:hover {
  background-color: #0069d9;
}

.calculate-btn:active {
  transform: translateY(1px);
}

.results-container {
  margin-top: 2.5rem;
  border-top: 1px solid var(--border-color);
  padding-top: 2rem;
  animation: fadeIn 0.5s ease-in-out;
}

@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.results-container h3 {
  text-align: center;
  font-size: 1.5rem;
  margin-bottom: 1.5rem;
}

.results-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: 1rem;
  margin-bottom: 2.5rem;
}

.result-card {
  background-color: var(--surface-color);
  padding: 1.25rem;
  border-radius: 8px;
  text-align: center;
  border: 1px solid var(--border-color);
}

.result-label {
  display: block;
  font-size: 0.85rem;
  color: var(--text-muted-color);
  margin-bottom: 0.5rem;
}

.result-value {
  display: block;
  font-size: 1.4rem;
  font-weight: 700;
  color: var(--primary-color);
}

.timeline-container {
    padding: 2rem 0;
}

.timeline-container h4 {
  text-align: center;
  font-size: 1.2rem;
  margin-bottom: 2rem;
}

.progress-bar-wrapper {
  position: relative;
  width: 100%;
  padding: 0 1rem;
  box-sizing: border-box;
}

.progress-bar-background {
  width: 100%;
  height: 8px;
  background-color: var(--border-color);
  border-radius: 4px;
  position: absolute;
  top: 5px; 
  left: 0;
  z-index: 1;
}

.progress-bar-fill {
  width: 100%;
  height: 8px;
  background-color: var(--success-color);
  border-radius: 4px;
  position: absolute;
  top: 5px; 
  left: 0;
  z-index: 2;
  transform-origin: left;
  animation: fillBar 1s cubic-bezier(0.25, 1, 0.5, 1);
}

@keyframes fillBar {
  from { transform: scaleX(0); }
  to { transform: scaleX(1); }
}

.milestone {
  position: absolute;
  top: 5px; /* Aligns with the bar's center */
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  z-index: 3;
}

.milestone::before {
  content: '';
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background-color: var(--background-color);
  border: 3px solid var(--success-color);
  box-sizing: border-box;
}

.milestone-label {
  position: absolute;
  top: -25px;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--text-color);
}

.milestone-date {
  position: absolute;
  top: 25px;
  font-size: 0.75rem;
  color: var(--text-muted-color);
  white-space: nowrap;
}


@media (max-width: 600px) {
  .audiobook-calculator-container {
    padding: 1.5rem;
  }
  .form-row {
    grid-template-columns: 1fr;
  }
  .results-grid {
    grid-template-columns: 1fr 1fr;
  }
  .milestone-date {
    font-size: 0.7rem;
  }
  .milestone-label {
      font-size: 0.75rem;
      top: -22px;
  }
}


/* General fix for unwanted horizontal scrolling */
html, body {
    max-width: 100%;
    overflow-x: hidden;
}

/* Ensure containers fit smaller screens */
.container, .page-wrapper, .tool-wrapper, .results-container {
    width: 100%;
    max-width: 100%;
    box-sizing: border-box;
}

/* Make ad sidebars responsive */
.ad-sidebar {
    max-width: 100%;
    overflow-x: hidden;
}

/* Results grid fix for small screens */
.results-grid {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
}
.results-grid .result-card {
    flex: 1 1 calc(50% - 1rem);
    min-width: 150px;
}
@media (max-width: 600px) {
    .results-grid .result-card {
        flex: 1 1 100%;
    }
}

/* Timeline responsiveness */
.timeline-container {
    overflow-x: auto;
    max-width: 100%;
}
.progress-bar-wrapper {
    min-width: 300px;
}