body {
  font-family: Arial, sans-serif;
  margin: 0;
  padding: 0;
  background: #f5f5f5;
  color: #333;
}
header {
  background-color: #007bff;
  color: white;
  padding: 20px;
  text-align: center;
}
main {
  padding: 20px;
}
input[type="file"] {
  margin-top: 10px;
}
canvas {
  max-width: 100%;
  margin-bottom: 40px;
}
/* All the CSS rules from the original <style> block go here */
* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  min-height: 100vh;
  padding: 20px;
}

.container {
  max-width: 1400px;
  margin: 0 auto;
  background: white;
  border-radius: 20px;
  box-shadow: 0 20px 60px rgba(0,0,0,0.3);
  overflow: hidden;
}

header {
  background: linear-gradient(135deg, #25D366 0%, #128C7E 100%);
  color: white;
  padding: 40px;
  text-align: center;
  position: relative;
  overflow: hidden;
}

header::before {
  content: '💬';
  position: absolute;
  font-size: 200px;
  opacity: 0.1;
  top: -50px;
  right: -50px;
}

h1 {
  font-size: 2.5em;
  margin-bottom: 10px;
  position: relative;
  z-index: 1;
}

.subtitle {
  font-size: 1.1em;
  opacity: 0.9;
  position: relative;
  z-index: 1;
}

.upload-section {
  padding: 30px;
  text-align: center;
  background: #f8f9fa;
  border-bottom: 2px solid #e9ecef;
}

.file-input-wrapper {
  position: relative;
  display: inline-block;
}

input[type="file"] {
  position: absolute;
  opacity: 0;
  width: 100%;
  height: 100%;
  cursor: pointer;
}

.upload-btn {
  background: linear-gradient(135deg, #25D366 0%, #128C7E 100%);
  color: white;
  padding: 15px 40px;
  border-radius: 50px;
  font-size: 1.1em;
  font-weight: 600;
  cursor: pointer;
  transition: transform 0.2s, box-shadow 0.2s;
  display: inline-block;
  box-shadow: 0 4px 15px rgba(37, 211, 102, 0.4);
}

.upload-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(37, 211, 102, 0.6);
}

.file-name {
  margin-top: 15px;
  font-size: 0.95em;
  color: #666;
  font-style: italic;
}

.tabs {
  display: flex;
  background: #f8f9fa;
  padding: 0 20px;
  overflow-x: auto;
  border-bottom: 2px solid #e9ecef;
}

.tab-btn {
  padding: 18px 30px;
  border: none;
  background: transparent;
  cursor: pointer;
  font-size: 1em;
  font-weight: 600;
  color: #666;
  transition: all 0.3s;
  border-bottom: 3px solid transparent;
  white-space: nowrap;
}

.tab-btn:hover {
  color: #25D366;
  background: rgba(37, 211, 102, 0.05);
}

.tab-btn.active {
  color: #25D366;
  border-bottom-color: #25D366;
  background: white;
}

.tab-content {
  padding: 40px;
  display: none;
  animation: fadeIn 0.3s;
}

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

.stats-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 20px;
  margin-bottom: 40px;
}

.stat-card {
  background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
  color: white;
  padding: 25px;
  border-radius: 15px;
  box-shadow: 0 4px 15px rgba(0,0,0,0.1);
  transition: transform 0.2s;
}

.stat-card:hover {
  transform: translateY(-5px);
}

.stat-card h3 {
  font-size: 0.9em;
  opacity: 0.9;
  margin-bottom: 10px;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.stat-card .value {
  font-size: 2.5em;
  font-weight: bold;
  margin-bottom: 5px;
}

.stat-card .label {
  font-size: 0.85em;
  opacity: 0.8;
}

.chart-container {
  background: white;
  padding: 25px;
  border-radius: 15px;
  margin-bottom: 30px;
  box-shadow: 0 2px 10px rgba(0,0,0,0.05);
  border: 1px solid #e9ecef;
}

.chart-container h3 {
  margin-bottom: 20px;
  color: #333;
  font-size: 1.3em;
  padding-bottom: 10px;
  border-bottom: 2px solid #25D366;
}

canvas {
  max-width: 100%;
  height: auto !important;
}

#wordcloud {
  width: 100%;
  height: 400px;
  border: 1px solid #e9ecef;
  border-radius: 10px;
  background: white;
}

.info-box {
  background: #d1ecf1;
  color: #0c5460;
  padding: 20px;
  border-radius: 10px;
  margin-bottom: 30px;
  border-left: 4px solid #17a2b8;
}

.info-box h4 {
  margin-bottom: 10px;
}

.info-box ul {
  margin-left: 20px;
}

/* Game Styles */
.game-container {
  background: linear-gradient(135deg, #fa709a 0%, #fee140 100%);
  padding: 30px;
  border-radius: 15px;
  margin-bottom: 30px;
  color: white;
  box-shadow: 0 4px 15px rgba(0,0,0,0.2);
}

.game-message {
  background: rgba(255,255,255,0.2);
  padding: 20px;
  border-radius: 10px;
  margin: 20px 0;
  font-size: 1.1em;
  line-height: 1.6;
  backdrop-filter: blur(10px);
}

.game-options {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 15px;
  margin: 20px 0;
}

.game-btn {
  padding: 15px 25px;
  background: white;
  color: #333;
  border: none;
  border-radius: 10px;
  font-size: 1em;
  font-weight: 600;
  cursor: pointer;
  transition: all 0.3s;
  box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.game-btn:hover {
  transform: translateY(-2px);
  box-shadow: 0 4px 15px rgba(0,0,0,0.2);
}

.game-btn.correct {
  background: #43e97b;
  color: white;
}

.game-btn.incorrect {
  background: #f5576c;
  color: white;
}

.game-score {
  text-align: center;
  font-size: 1.5em;
  font-weight: bold;
  margin: 15px 0;
}

.game-controls {
  display: flex;
  gap: 15px;
  justify-content: center;
  margin-top: 20px;
}

.prediction-card {
  background: linear-gradient(135deg, #4facfe 0%, #00f2fe 100%);
  padding: 25px;
  border-radius: 15px;
  margin-bottom: 20px;
  color: white;
  box-shadow: 0 4px 15px rgba(0,0,0,0.1);
}

.prediction-card h4 {
  font-size: 1.3em;
  margin-bottom: 15px;
  opacity: 0.95;
}

.prediction-value {
  font-size: 2em;
  font-weight: bold;
  margin: 10px 0;
}

.prediction-details {
  font-size: 0.9em;
  opacity: 0.9;
  line-height: 1.6;
}

.relationship-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
  gap: 20px;
  margin-bottom: 30px;
}

.relationship-card {
  background: white;
  padding: 20px;
  border-radius: 15px;
  box-shadow: 0 2px 10px rgba(0,0,0,0.05);
  border: 1px solid #e9ecef;
}

.relationship-card h4 {
  color: #333;
  margin-bottom: 15px;
  font-size: 1.1em;
}

.relationship-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 10px 0;
  border-bottom: 1px solid #f0f0f0;
}

.relationship-item:last-child {
  border-bottom: none;
}

.relationship-label {
  font-weight: 600;
  color: #555;
}

.relationship-value {
  color: #25D366;
  font-weight: bold;
  font-size: 1.1em;
}

@media (max-width: 768px) {
  h1 {
    font-size: 1.8em;
  }
  
  .tabs {
    padding: 0 10px;
  }
  
  .tab-btn {
    padding: 15px 20px;
    font-size: 0.9em;
  }
  
  .tab-content {
    padding: 20px;
  }
  
  .stats-grid {
    grid-template-columns: 1fr;
  }

  .game-options {
    grid-template-columns: 1fr;
  }
}
/* Add these styles to your existing style.css */

.date-filter-section {
  display: flex;
  align-items: center;
  justify-content: center;
  flex-wrap: wrap; /* Allow wrapping on small screens */
  gap: 10px; /* Space between filter elements */
}

.date-filter-section label {
  font-weight: 600;
  color: #333;
}

.date-filter-section .filter-input {
  padding: 8px 12px;
  border: 1px solid #ccc;
  border-radius: 8px;
  font-size: 0.9em;
  transition: border-color 0.2s;
}

.date-filter-section .filter-input:focus {
  outline: none;
  border-color: #25D366;
  box-shadow: 0 0 0 2px rgba(37, 211, 102, 0.2);
}

/* Heatmap specific styles */
.heatmap-grid {
    display: grid;
    grid-template-columns: auto repeat(24, 1fr); /* 1 for labels, 24 for hours */
    grid-template-rows: auto repeat(7, 1fr); /* 1 for labels, 7 for days */
    gap: 1px;
    border: 1px solid #eee;
    background-color: #eee;
    max-width: fit-content;
    margin: 20px auto;
}

.heatmap-cell, .heatmap-label {
    padding: 5px;
    text-align: center;
    font-size: 0.7em;
    color: #555;
    background-color: white; /* Default background for labels */
    display: flex;
    align-items: center;
    justify-content: center;
}

.heatmap-cell {
    background-color: #f0f0f0; /* Default cell background */
    transition: background-color 0.3s ease;
}

/* Styles for the corner cell (empty) */
.heatmap-grid .corner-cell {
    background-color: transparent;
}

/* Hour labels at the top */
.heatmap-grid .hour-label {
    font-weight: bold;
    background-color: #e9ecef;
}

/* Day labels on the left */
.heatmap-grid .day-label {
    font-weight: bold;
    background-color: #e9ecef;
    text-align: left;
    padding-left: 10px;
}

.heatmap-grid {
  display: grid;
  gap: 2px;
  margin-top: 10px;
}
.heatmap-label {
  font-size: 12px;
  font-weight: bold;
  text-align: center;
  padding: 2px;
}
.heatmap-cell {
  text-align: center;
  font-size: 11px;
  padding: 4px;
  border-radius: 4px;
  color: #000;
}
.corner-cell {
  background: transparent;
}
.user-label {
  writing-mode: vertical-rl;
  transform: rotate(180deg);
}