/* ============================================
   AI Case Study - Chart Base System
   Shared styles for all embedded charts
   ============================================ */

@import url('https://fonts.googleapis.com/css2?family=IBM+Plex+Sans:wght@400;500;600&family=IBM+Plex+Serif:wght@400;500;600&display=swap');

/* ============================================
   CSS Variables
   ============================================ */

:root {
  --primary: #7c5cdb;
  --primary-dark: #6b4bc9;
  --primary-label: #5a3db8;
  --text: #454f5b;
  --heading: #212b36;
  --muted: #4a5568;
  --bg: #fff;
  --bg-alt: #f9fafb;
  --border: #e5e8eb;
  --accent-bg: #f4f0ff;
  --accent-border: #d4c2ff;
}

/* ============================================
   Base Reset
   ============================================ */

*, *::before, *::after {
  box-sizing: border-box;
}

body {
  margin: 0;
  padding: 0;
  font-family: 'IBM Plex Sans', -apple-system, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  font-size: 17px;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

/* ============================================
   Chart Container
   ============================================ */

.chart-container {
  background: var(--bg);
  border: none;
  padding: 24px;
  margin: 0;
}

.chart-title {
  font-family: 'IBM Plex Serif', Georgia, serif;
  font-size: 18px;
  font-weight: 600;
  color: var(--heading);
  margin-bottom: 4px;
}

.chart-subtitle {
  font-size: 14px;
  color: var(--muted);
  margin-bottom: 20px;
}

.chart-footer {
  margin-top: 24px;
  padding-top: 20px;
  border-top: 1px solid var(--border);
  display: flex;
  gap: 32px;
  flex-wrap: wrap;
}

.chart-stat {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.chart-stat-value {
  font-family: 'IBM Plex Serif', Georgia, serif;
  font-size: 20px;
  font-weight: 600;
  color: var(--heading);
}

.chart-stat-label {
  font-size: 13px;
  color: var(--muted);
}

@media (max-width: 640px) {
  .chart-container { padding: 16px; }
  .chart-title { font-size: 16px; }
  .chart-subtitle { font-size: 13px; margin-bottom: 16px; }
  .chart-footer { gap: 20px; }
  .chart-stat-value { font-size: 18px; }
  .chart-stat-label { font-size: 11px; }
}

/* ============================================
   Tooltip System
   ============================================ */

.chart-tooltip {
  position: absolute;
  left: 50%;
  bottom: calc(100% + 8px);
  transform: translateX(-50%);
  background: var(--heading);
  color: #fff;
  padding: 10px 14px;
  border-radius: 6px;
  font-size: 13px;
  line-height: 1.5;
  white-space: nowrap;
  opacity: 0;
  visibility: hidden;
  transition: opacity 0.2s, visibility 0.2s, transform 0.2s;
  transform: translateX(-50%) translateY(4px);
  z-index: 100;
  box-shadow: 0 4px 12px rgba(0,0,0,0.15);
  pointer-events: none;
}

.chart-tooltip::after {
  content: "";
  position: absolute;
  top: 100%;
  left: 50%;
  transform: translateX(-50%);
  border: 6px solid transparent;
  border-top-color: var(--heading);
}

/* Tooltip below variant - for points near the top of chart */
.tooltip-below .chart-tooltip,
.chart-tooltip.below {
  bottom: auto;
  top: calc(100% + 8px);
  transform: translateX(-50%) translateY(-4px);
}

.tooltip-below:hover .chart-tooltip,
.chart-tooltip.below:hover {
  transform: translateX(-50%) translateY(0);
}

.tooltip-below .chart-tooltip::after,
.chart-tooltip.below::after {
  top: auto;
  bottom: 100%;
  border-top-color: transparent;
  border-bottom-color: var(--heading);
}

/* Mobile tooltip fixes */
@media (max-width: 640px) {
  .chart-tooltip {
    max-width: calc(100vw - 32px);
    white-space: normal;
    min-width: 140px;
  }

  /* On mobile, show tooltips below by default to prevent iframe cutoff */
  .tooltip-below .chart-tooltip,
  .chart-tooltip.below {
    left: 50%;
    right: auto;
    transform: translateX(-50%) translateY(-4px);
  }
}

.tooltip-title {
  font-weight: 600;
  margin-bottom: 6px;
  color: rgba(255,255,255,0.9);
}

.tooltip-row {
  display: flex;
  justify-content: space-between;
  gap: 16px;
}

.tooltip-label {
  color: rgba(255,255,255,0.7);
}

.tooltip-value {
  font-weight: 500;
  font-variant-numeric: tabular-nums;
}

.tooltip-highlight {
  color: #a888f9;
}

.tooltip-divider {
  height: 1px;
  background: rgba(255,255,255,0.15);
  margin: 8px 0;
}

/* ============================================
   Animation Keyframes
   ============================================ */

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

@keyframes barGrowY {
  from {
    transform: scaleY(0);
    opacity: 0;
  }
  to {
    transform: scaleY(1);
    opacity: 1;
  }
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

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

/* ============================================
   Common Utility Classes
   ============================================ */

.visually-hidden {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border: 0;
}