/* ===== Global Dark Theme ===== */
body {
  background: #000;
  color: #ddd;
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  margin: 0;
  padding: 0;
}

/* ===== Main container ===== */
main {
  max-width: 1200px;
  margin: 40px auto;
  padding: 20px;
  background: #111;
  border-radius: 10px;
  box-shadow: 0 0 18px rgba(255, 255, 255, 0.05);
}

/* ===== Headings ===== */
main h2 {
  text-align: center;
  font-size: 2rem;
  color: #4c6ef5;
  margin-bottom: 30px;
}

main h3 {
  font-size: 1.3rem;
  color: #fff;
  margin: 30px 0 15px 0;
  text-align: center;
  font-weight: 600;
}

/* ===== File input ===== */
#fileInput {
  display: block;
  margin: 0 auto 30px auto;
  padding: 10px 14px;
  border: 1px solid #444;
  border-radius: 6px;
  font-size: 14px;
  background: #1e1e1e;
  color: #eee;
  cursor: pointer;
  transition: border 0.2s, background 0.2s;
}

#fileInput:hover {
  border-color: #4c6ef5;
  background: #2a2a2a;
}

/* ===== Chart containers ===== */
.chart-container {
  position: relative;
  width: 90%;
  max-width: 1000px;
  height: 500px;
  margin: 0 auto 40px auto;
  background: #1a1a1a;
  border: 1px solid #333;
  border-radius: 10px;
  padding: 15px;
  box-shadow: 0 3px 8px rgba(255, 255, 255, 0.05);
}

/* Chart.js canvases */
canvas {
  width: 100% !important;
  height: 100% !important;
  display: block;
}

/* ===== Chart buttons ===== */
.chart-actions {
  text-align: center;
  margin: -20px 0 40px 0;
}

.chart-actions.top {
  margin: 0 0 10px 0; /* Above the chart */
}

.chart-actions button {
  margin: 5px;
  padding: 6px 12px;
  background: #4c6ef5;
  color: white;
  border: none;
  border-radius: 5px;
  cursor: pointer;
  font-size: 14px;
  transition: background 0.2s, transform 0.1s;
}

.chart-actions button:hover {
  background: #364fc7;
  transform: translateY(-1px);
}

/* ===== Section dividers ===== */
section {
  border-top: 1px solid #222;
  padding-top: 100px;
  margin-bottom: 100px; /* ✅ adds space between sections */
}


/* ===== Scrollbar styling ===== */
::-webkit-scrollbar {
  width: 8px;
  height: 8px;
}

::-webkit-scrollbar-thumb {
  background: #333;
  border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
  background: #4c6ef5;
}

/* ===== Responsive adjustments ===== */
@media (max-width: 900px) {
  main {
    padding: 15px;
    margin: 20px auto;
  }

  .chart-container {
    height: 350px;
    padding: 10px;
  }

  main h2 {
    font-size: 1.6rem;
  }

  main h3 {
    font-size: 1.1rem;
  }

  #fileInput {
    width: 90%;
  }
}

/* ===== Animation (optional subtle fade-in) ===== */
.chart-container,
main h3 {
  animation: fadeIn 0.6s ease-in;
}

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

#heatmap-container {
  min-height: 650px;
}