:root {
  --sankey-primary: #3b82f6;
  --sankey-primary-dark: #2563eb;
  --sankey-secondary: #64748b;
  --sankey-bg: #f8fafc;
  --sankey-card-bg: #ffffff;
  --sankey-border: #e2e8f0;
  --sankey-text: #1e293b;
  --sankey-text-light: #64748b;
  --sankey-success: #10b981;
  --sankey-danger: #ef4444;
  --sankey-shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
  --sankey-shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
}

.sankey-app {
  min-height: 100vh;
  background: var(--sankey-bg);
  font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
  color: var(--sankey-text);
  line-height: 1.6;
}

/* Hero Section */
.sankey-hero {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  padding: 3rem 2rem;
  display: grid;
  grid-template-columns: 2fr 1fr;
  gap: 2rem;
  max-width: 1400px;
  margin: 0 auto;
}

.sankey-hero-copy {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.sankey-eyebrow {
  font-size: 0.875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  opacity: 0.9;
}

.sankey-hero h1 {
  font-size: 2.5rem;
  font-weight: 700;
  margin: 0;
  line-height: 1.2;
}

.sankey-subtitle {
  font-size: 1.125rem;
  opacity: 0.95;
  max-width: 600px;
}

.sankey-hero-note {
  background: rgba(255, 255, 255, 0.15);
  backdrop-filter: blur(10px);
  padding: 1.5rem;
  border-radius: 12px;
  border: 1px solid rgba(255, 255, 255, 0.2);
}

.sankey-hero-note h2 {
  font-size: 1.125rem;
  font-weight: 600;
  margin: 0 0 0.5rem 0;
}

.sankey-hero-note p {
  font-size: 0.9375rem;
  margin: 0;
  opacity: 0.9;
}

/* Layout */
.sankey-layout {
  display: grid;
  grid-template-columns: 350px 1fr;
  gap: 2rem;
  max-width: 1400px;
  margin: 2rem auto;
  padding: 0 2rem;
}

/* Panels */
.sankey-panel {
  background: var(--sankey-card-bg);
  border-radius: 12px;
  border: 1px solid var(--sankey-border);
  box-shadow: var(--sankey-shadow);
  padding: 1.5rem;
  margin-bottom: 1.5rem;
}

.sankey-panel-head {
  margin-bottom: 1.5rem;
}

.sankey-panel-head h2 {
  font-size: 1.25rem;
  font-weight: 700;
  margin: 0 0 0.5rem 0;
  color: var(--sankey-text);
}

.sankey-panel-head p {
  font-size: 0.875rem;
  color: var(--sankey-text-light);
  margin: 0;
}

/* Controls Panel */
.sankey-controls-panel {
  position: sticky;
  top: 2rem;
  height: fit-content;
}

.sankey-presets {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.5rem;
  margin-bottom: 1.5rem;
}

.sankey-preset-btn {
  background: var(--sankey-bg);
  border: 1px solid var(--sankey-border);
  border-radius: 6px;
  padding: 0.625rem 0.75rem;
  font-size: 0.8125rem;
  font-weight: 500;
  cursor: pointer;
  transition: all 0.2s;
  color: var(--sankey-text);
}

.sankey-preset-btn:hover {
  background: var(--sankey-primary);
  color: white;
  border-color: var(--sankey-primary);
}

/* Input Section */
.sankey-input-section {
  margin-bottom: 1.5rem;
}

.sankey-input-section h3 {
  font-size: 1rem;
  font-weight: 600;
  margin: 0 0 1rem 0;
  color: var(--sankey-text);
}

.sankey-links-editor {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  margin-bottom: 1rem;
}

.sankey-link-row {
  display: grid;
  grid-template-columns: 1fr 1fr 80px 32px;
  gap: 0.5rem;
  align-items: center;
}

.sankey-link-row input {
  width: 100%;
  padding: 0.5rem;
  border: 1px solid var(--sankey-border);
  border-radius: 6px;
  font-size: 0.8125rem;
  transition: border-color 0.2s;
}

.sankey-link-row input:focus {
  outline: none;
  border-color: var(--sankey-primary);
}

.sankey-link-row input::placeholder {
  color: var(--sankey-text-light);
}

.sankey-remove-link {
  background: transparent;
  border: none;
  color: var(--sankey-danger);
  cursor: pointer;
  font-size: 1.25rem;
  line-height: 1;
  padding: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform 0.2s;
}

.sankey-remove-link:hover {
  transform: scale(1.1);
}

.sankey-add-link-btn {
  width: 100%;
  background: transparent;
  border: 2px dashed var(--sankey-border);
  border-radius: 6px;
  padding: 0.625rem;
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--sankey-primary);
  cursor: pointer;
  transition: all 0.2s;
}

.sankey-add-link-btn:hover {
  background: var(--sankey-primary);
  color: white;
  border-color: var(--sankey-primary);
}

/* Actions */
.sankey-actions {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0.75rem;
  margin-bottom: 1.5rem;
}

.sankey-btn {
  padding: 0.75rem 1rem;
  border-radius: 6px;
  font-size: 0.875rem;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.2s;
  border: none;
}

.sankey-btn-primary {
  background: var(--sankey-primary);
  color: white;
}

.sankey-btn-primary:hover {
  background: var(--sankey-primary-dark);
}

.sankey-btn-secondary {
  background: var(--sankey-bg);
  color: var(--sankey-text);
  border: 1px solid var(--sankey-border);
}

.sankey-btn-secondary:hover {
  background: var(--sankey-border);
}

/* Color Section */
.sankey-color-section {
  margin-bottom: 1.5rem;
}

.sankey-color-section h3 {
  font-size: 1rem;
  font-weight: 600;
  margin: 0 0 0.75rem 0;
  color: var(--sankey-text);
}

.sankey-color-options {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.sankey-color-option {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 0.875rem;
  cursor: pointer;
}

.sankey-color-option input[type="radio"] {
  cursor: pointer;
}

/* Explainers */
.sankey-explainers {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.sankey-mini-card {
  background: var(--sankey-bg);
  padding: 1rem;
  border-radius: 8px;
  border: 1px solid var(--sankey-border);
}

.sankey-mini-card h3 {
  font-size: 0.875rem;
  font-weight: 600;
  margin: 0 0 0.5rem 0;
  color: var(--sankey-text);
}

.sankey-mini-card p {
  font-size: 0.8125rem;
  color: var(--sankey-text-light);
  margin: 0;
}

/* Main Section */
.sankey-main {
  display: flex;
  flex-direction: column;
  gap: 1.5rem;
}

/* Metrics */
.sankey-metrics {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 1rem;
}

.sankey-metric-card {
  background: var(--sankey-card-bg);
  padding: 1rem;
  border-radius: 8px;
  border: 1px solid var(--sankey-border);
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
}

.sankey-metric-card span {
  font-size: 0.75rem;
  font-weight: 500;
  color: var(--sankey-text-light);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.sankey-metric-card strong {
  font-size: 1.5rem;
  font-weight: 700;
  color: var(--sankey-text);
}

/* Diagram Panel */
.sankey-diagram-panel {
  min-height: 500px;
}

.sankey-diagram-container {
  width: 100%;
  height: 500px;
  background: var(--sankey-bg);
  border-radius: 8px;
  border: 1px solid var(--sankey-border);
  overflow: hidden;
}

/* Data Table */
.sankey-data-table-container {
  overflow-x: auto;
}

.sankey-data-table {
  width: 100%;
  border-collapse: collapse;
  font-size: 0.875rem;
}

.sankey-data-table th {
  background: var(--sankey-bg);
  padding: 0.75rem;
  text-align: left;
  font-weight: 600;
  color: var(--sankey-text);
  border-bottom: 2px solid var(--sankey-border);
}

.sankey-data-table td {
  padding: 0.75rem;
  border-bottom: 1px solid var(--sankey-border);
  color: var(--sankey-text);
}

.sankey-data-table tbody tr:hover {
  background: var(--sankey-bg);
}

/* Education Grid */
.sankey-education-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 1.5rem;
}

.sankey-content {
  display: flex;
  flex-direction: column;
  gap: 1rem;
}

.sankey-content p {
  font-size: 0.875rem;
  color: var(--sankey-text-light);
  line-height: 1.7;
}

.sankey-applications-list,
.sankey-audience-list {
  list-style: none;
  padding: 0;
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
}

.sankey-applications-list li,
.sankey-audience-list li {
  font-size: 0.875rem;
  color: var(--sankey-text-light);
  padding-left: 1.5rem;
  position: relative;
  line-height: 1.6;
}

.sankey-applications-list li::before,
.sankey-audience-list li::before {
  content: "→";
  position: absolute;
  left: 0;
  color: var(--sankey-primary);
  font-weight: 600;
}

/* Sankey SVG Styles */
.sankey-svg {
  width: 100%;
  height: 100%;
}

.sankey-link {
  fill: none;
  stroke-opacity: 0.4;
  transition: stroke-opacity 0.2s;
}

.sankey-link:hover {
  stroke-opacity: 0.7;
}

.sankey-link.highlighted {
  stroke-opacity: 0.8;
}

.sankey-link.dimmed {
  stroke-opacity: 0.1;
}

.sankey-node {
  cursor: move;
  transition: opacity 0.2s;
}

.sankey-node:hover {
  opacity: 0.8;
}

.sankey-node-rect {
  fill: #cbd5e1;
  stroke: #94a3b8;
  stroke-width: 1px;
}

.sankey-node text {
  font-size: 12px;
  fill: var(--sankey-text);
  pointer-events: none;
}

.sankey-tooltip {
  position: absolute;
  background: rgba(0, 0, 0, 0.9);
  color: white;
  padding: 0.5rem 0.75rem;
  border-radius: 6px;
  font-size: 0.8125rem;
  pointer-events: none;
  z-index: 1000;
  white-space: nowrap;
}

/* Responsive Design */
@media (max-width: 1024px) {
  .sankey-layout {
    grid-template-columns: 1fr;
  }

  .sankey-controls-panel {
    position: static;
  }

  .sankey-hero {
    grid-template-columns: 1fr;
  }

  .sankey-metrics {
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (max-width: 640px) {
  .sankey-hero {
    padding: 2rem 1rem;
  }

  .sankey-hero h1 {
    font-size: 1.75rem;
  }

  .sankey-subtitle {
    font-size: 1rem;
  }

  .sankey-layout {
    padding: 0 1rem;
    gap: 1.5rem;
  }

  .sankey-presets {
    grid-template-columns: 1fr;
  }

  .sankey-link-row {
    grid-template-columns: 1fr;
    gap: 0.5rem;
  }

  .sankey-metrics {
    grid-template-columns: 1fr;
  }

  .sankey-education-grid {
    grid-template-columns: 1fr;
  }
}