:root {
  --primary: #3498db;
  --secondary: #2ecc71;
  --dark: #2c3e50;
  --light: #ecf0f1;
  --accent: #e74c3c;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

body {
  font-family: "Segoe UI", Tahoma, Geneva, Verdana, sans-serif;
  line-height: 1.6;
  color: var(--dark);
  background-color: #f9f9f9;
  padding: 20px;
}

.container {
  max-width: 800px;
  margin: 0 auto;
  background: white;
  padding: 30px;
  border-radius: 10px;
  box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

header {
  text-align: center;
  margin-bottom: 40px;
}

h1 {
  color: var(--primary);
  margin-bottom: 10px;
}

.subtitle {
  color: #7f8c8d;
  font-weight: normal;
}

.math-card {
  background: var(--light);
  border-left: 4px solid var(--primary);
  padding: 20px;
  margin-bottom: 30px;
  border-radius: 4px;
}

.math-title {
  color: var(--primary);
  margin-bottom: 15px;
}

.math-container {
  overflow-x: auto;
  padding: 15px;
  background: white;
  border-radius: 4px;
  margin: 15px 0;
  box-shadow: 0 2px 5px rgba(0, 0, 0, 0.05);
}

.explanation {
  margin-top: 15px;
  padding-top: 15px;
  border-top: 1px dashed #bdc3c7;
  color: #7f8c8d;
  font-style: italic;
}

.math-equation {
  font-size: 1.2em;
  text-align: center;
}

footer {
  text-align: center;
  margin-top: 40px;
  color: #7f8c8d;
  font-size: 0.9em;
}

@media (max-width: 600px) {
  .container {
    padding: 15px;
  }

  .math-container {
    padding: 10px;
  }
}