/* ==========================================================================
   Climate Change & Solar Visualization Website - Minimal Design System
   Inspired by Apple, Linear, Notion, and Stripe Documentation
   ========================================================================== */

:root {
  /* Color Palette */
  --bg-color: #ffffff;
  --bg-subtle: #fafafa;
  --card-bg: #ffffff;
  
  --text-primary: #111111;
  --text-secondary: #666666;
  --text-muted: #888888;
  
  --border-color: #e4e4e7;
  --border-subtle: #f4f4f5;

  --accent-green: #1B8F4B;
  --accent-green-light: #e8f5ed;
  --solar-yellow: #FDB813;
  --solar-yellow-light: #fffbeb;

  /* Typography */
  --font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'SF Pro Display', 'Segoe UI', Roboto, sans-serif;

  /* Layout & Spacing */
  --container-max-width: 1040px;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 14px;
  
  /* Shadows - Extremely Subtle */
  --shadow-card: 0 1px 3px rgba(0, 0, 0, 0.04), 0 1px 2px rgba(0, 0, 0, 0.02);
  --shadow-hover: 0 8px 24px rgba(0, 0, 0, 0.06);

  --transition: 0.2s cubic-bezier(0.16, 1, 0.3, 1);
}

/* Reset & Base Styles */
* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font-family);
  background-color: var(--bg-color);
  color: var(--text-primary);
  line-height: 1.6;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

.container {
  width: 100%;
  max-width: var(--container-max-width);
  margin: 0 auto;
  padding: 0 1.75rem;
}

/* Hero Section */
.hero-section {
  padding: 4rem 0 1.5rem;
  text-align: left;
}

.hero-tag {
  display: inline-flex;
  align-items: center;
  gap: 0.4rem;
  font-size: 0.8rem;
  font-weight: 600;
  color: var(--accent-green);
  background-color: var(--accent-green-light);
  padding: 0.25rem 0.75rem;
  border-radius: 9999px;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: 1.25rem;
}

.hero-title {
  font-size: clamp(2.5rem, 5vw, 4rem);
  font-weight: 800;
  letter-spacing: -0.04em;
  line-height: 1.1;
  color: var(--text-primary);
  margin-bottom: 0.5rem;
  max-width: 820px;
}

/* Visualization Cards Grid */
.vis-section {
  padding: 4.5rem 0;
}

.vis-cards-container {
  display: flex;
  flex-direction: column;
  gap: 4rem;
}

/* Alternate Shift (Zigzag) Layout for Cards */
@media (min-width: 768px) {
  .vis-cards-container {
    gap: 4.5rem;
  }

  .vis-card {
    width: calc(100% - 75px);
  }

  /* Odd Cards (1st, 3rd): Shifted Left */
  .vis-cards-container > article:nth-child(odd) {
    margin-right: auto;
    margin-left: 0;
  }

  /* Even Cards (2nd, 4th): Shifted Right */
  .vis-cards-container > article:nth-child(even) {
    margin-left: auto;
    margin-right: 0;
  }
}

@media (min-width: 1024px) {
  .vis-card {
    width: calc(100% - 110px);
  }
}

/* Visualization Card */
.vis-card {
  background-color: var(--card-bg);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 2.25rem 2rem 2rem;
  box-shadow: var(--shadow-card);
  transition: box-shadow var(--transition), border-color var(--transition);
  position: relative;
  overflow: hidden;
}

.vis-card:hover {
  box-shadow: var(--shadow-hover);
  border-color: #d4d4d8;
}

/* Subtle Geometric Motif Accent Line */
.vis-card-accent-motif {
  position: absolute;
  top: 0;
  left: 2rem;
  width: 48px;
  height: 3px;
  background: linear-gradient(90deg, var(--solar-yellow) 0%, var(--accent-green) 100%);
  border-radius: 0 0 4px 4px;
  opacity: 0.85;
}

.vis-card-header {
  margin-bottom: 1.25rem;
}

.vis-card-top-meta {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.4rem;
}

.vis-card-number {
  font-family: 'SF Mono', 'Roboto Mono', Monaco, monospace;
  font-size: 0.75rem;
  font-weight: 600;
  color: #a1a1aa;
  letter-spacing: 0.05em;
}

.vis-card-category {
  font-size: 0.75rem;
  font-weight: 600;
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
}

.vis-card-title {
  font-size: 1.5rem;
  font-weight: 700;
  letter-spacing: -0.02em;
  color: var(--text-primary);
  margin-bottom: 0.6rem;
}

.vis-card-description {
  font-size: 0.975rem;
  color: var(--text-secondary);
  line-height: 1.6;
  max-width: 860px;
}

/* Tableau Embed Container */
.tableau-embed-container {
  width: 100%;
  min-height: 480px;
  background-color: var(--bg-subtle);
  border: 1px solid var(--border-subtle);
  border-radius: var(--radius-md);
  margin: 1.5rem 0;
  overflow: hidden;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
}

.tableau-embed-container iframe,
.tableau-embed-container .tableauPlaceholder,
.tableau-embed-container object {
  width: 100% !important;
  max-width: 100% !important;
}

.tableau-embed-container iframe {
  height: 100%;
  min-height: 480px;
  border: none;
}

/* Conclusion Section */
.conclusion-section {
  padding: 4.5rem 0;
  border-top: 1px solid var(--border-subtle);
  background: linear-gradient(180deg, #ffffff 0%, var(--bg-subtle) 100%);
}

.conclusion-card {
  background: linear-gradient(135deg, #ffffff 0%, #f4fbf7 100%);
  border: 1px solid var(--border-color);
  border-left: 5px solid var(--accent-green);
  border-radius: var(--radius-lg);
  padding: 2.5rem 2.25rem;
  box-shadow: 0 10px 30px -5px rgba(27, 143, 75, 0.12), 0 4px 12px -2px rgba(0, 0, 0, 0.03);
}

.conclusion-tag {
  font-size: 0.75rem;
  font-weight: 700;
  color: var(--accent-green);
  background-color: rgba(27, 143, 75, 0.1);
  padding: 0.25rem 0.65rem;
  border-radius: 4px;
  display: inline-block;
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 0.75rem;
}

.conclusion-title {
  font-size: 1.75rem;
  font-weight: 800;
  letter-spacing: -0.03em;
  color: var(--text-primary);
  margin-bottom: 1rem;
}

.conclusion-text {
  font-size: 1.125rem;
  color: var(--text-primary);
  line-height: 1.7;
  font-weight: 500;
}

/* Card Footer & Source */
.vis-card-footer {
  display: flex;
  flex-direction: column;
  gap: 0.75rem;
  border-top: 1px solid var(--border-subtle);
  padding-top: 1.25rem;
  margin-top: 1rem;
  font-size: 0.85rem;
}

.vis-source {
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 0.4rem;
}

.vis-source a {
  color: var(--text-secondary);
  text-decoration: underline;
  text-underline-offset: 3px;
  transition: color var(--transition);
}

.vis-source a:hover {
  color: var(--text-primary);
}

.vis-notes {
  font-size: 0.875rem;
  color: var(--text-secondary);
  background-color: var(--bg-subtle);
  padding: 0.75rem 1rem;
  border-radius: var(--radius-sm);
  border-left: 3px solid var(--solar-yellow);
}

/* Footer */
.site-footer {
  background-color: var(--bg-color);
  border-top: 1px solid var(--border-subtle);
  padding: 2.25rem 0;
}

.footer-inner {
  display: flex;
  justify-content: center;
  align-items: center;
}

.footer-credit {
  font-size: 0.8rem;
  color: var(--text-muted);
  letter-spacing: 0.04em;
  margin: 0;
}

/* Responsive Media Queries */
@media (max-width: 768px) {
  .hero-section {
    padding: 3.5rem 0 2.5rem;
  }

  .hero-title {
    font-size: 2.35rem;
  }

  .hero-subtitle {
    font-size: 1.05rem;
  }

  .vis-card {
    padding: 1.25rem;
  }

  .tableau-embed-container {
    min-height: 380px;
  }

  .conclusion-card {
    padding: 1.5rem 1.25rem;
  }

  .footer-inner {
    flex-direction: column;
    align-items: flex-start;
  }
}