* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
}

body {
  line-height: 1.6;
  color: #333;
  background: #fff;
}

.container {
  max-width: 1140px;
  margin: auto;
  padding: 0 20px;
}

header {
  background: #003366;
  color: #fff;
  padding: 20px 0;
}

header h1 {
  margin-bottom: 10px;
}

nav ul {
  display: flex;
  list-style: none;
  gap: 15px;
}

nav a {
  color: #fff;
  text-decoration: none;
}

.hero {
  background: linear-gradient(to right, #0052cc, #0073e6);
  color: #fff;
  padding: 60px 20px;
  text-align: center;
}

.hero h2 {
  font-size: 2.5em;
}

.btn {
  display: inline-block;
  background: #fff;
  color: #0052cc;
  padding: 10px 20px;
  margin-top: 20px;
  text-decoration: none;
  border-radius: 5px;
  font-weight: bold;
}

section {
  padding: 60px 20px;
}

.courses-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
  gap: 20px;
  margin-top: 20px;
}

.course {
  background: #f4f4f4;
  padding: 20px;
  border-radius: 10px;
  text-align: center;
}

.features {
  list-style: none;
  padding-left: 20px;
}

.features li {
  padding: 8px 0;
}

footer {
  background: #003366;
  color: #fff;
  text-align: center;
  padding: 20px 0;
}


/* --- Responsive Enhancements --- */


/* Responsive Containers */
.container {
  max-width: 1200px;
  margin: auto;
  padding: 0 20px;
}

/* Responsive Navigation */
nav ul {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  list-style: none;
  padding: 0;
}
nav li {
  margin: 10px;
}
nav a {
  padding: 10px 15px;
  text-decoration: none;
  color: white;
  background-color: #003366;
  border-radius: 5px;
}
nav a:hover {
  background-color: #00509e;
}

/* Images */
img {
  max-width: 100%;
  height: auto;
  display: block;
}

/* Responsive Tables */
table {
  width: 100%;
  border-collapse: collapse;
}
th, td {
  padding: 12px;
  text-align: center;
}
thead {
  background-color: #003366;
  color: #fff;
}
tbody tr:nth-child(even) {
  background-color: #f4f6f9;
}

/* Responsive Layouts */
@media screen and (max-width: 768px) {
  nav ul {
    flex-direction: column;
    align-items: center;
  }

  .flex, .row, .columns {
    flex-direction: column !important;
  }

  h1, h2, h3 {
    font-size: 1.5rem;
    text-align: center;
  }

  section, article {
    padding: 15px;
  }

  .container {
    padding: 0 10px;
  }

  table, thead, tbody, th, td, tr {
    display: block;
  }

  thead {
    display: none;
  }

  td {
    position: relative;
    padding-left: 50%;
    text-align: left;
  }

  td::before {
    position: absolute;
    left: 10px;
    width: 45%;
    white-space: nowrap;
    font-weight: bold;
    color: #333;
  }
}


/* --- Mobile Navigation Toggle --- */

/* Mobile Menu Toggle Button */
.menu-toggle {
  display: none;
  background-color: #003366;
  color: white;
  padding: 10px 15px;
  border: none;
  font-size: 16px;
  cursor: pointer;
  border-radius: 5px;
  margin: 10px auto;
  text-align: center;
}

@media (max-width: 768px) {
  .menu-toggle {
    display: block;
  }

  nav ul {
    display: none;
    flex-direction: column;
    background-color: #003366;
    border-radius: 5px;
    padding: 10px 0;
    margin: 10px 0;
  }

  nav ul.active {
    display: flex;
  }
}