* {
  box-sizing: border-box;
}

body {
  margin: 0;
  font-family: "Segoe UI", Arial, sans-serif;
  line-height: 1.6;
  color: #222;
}

header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 15px 40px;
  background: #002b45;
  color: white;
  position: sticky;
  top: 0;
  z-index: 1000;
}

.logo {
  font-weight: bold;
  font-size: 18px;
}

nav a {
  color: white;
  text-decoration: none;
  margin-left: 20px;
}

nav a:hover {
  color: #00bfff;
}

.menu-toggle {
  display: none;
  font-size: 24px;
  cursor: pointer;
}

.banner {
  height: 320px;
  background: linear-gradient(rgba(0,43,69,0.8), rgba(0,43,69,0.8)),
              url('../images/banner.jpg') center/cover no-repeat;
  display: flex;
  justify-content: center;
  align-items: center;
  text-align: center;
  color: white;
  padding: 20px;
}

.section {
  padding: 60px 40px;
  max-width: 1100px;
  margin: auto;
}

.gray {
  background: #f4f6f9;
}

.card-container {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}

.card {
  background: white;
  padding: 25px;
  border-radius: 8px;
  border: 1px solid #ddd;
  transition: 0.3s;
}

.card:hover {
  box-shadow: 0 6px 15px rgba(0,0,0,0.1);
}

.news {
  padding-left: 20px;
}

footer {
  text-align: center;
  padding: 20px;
  background: #002b45;
  color: white;
}

/* ===== 태블릿 ===== */
@media (max-width: 992px) {
  .card-container {
    grid-template-columns: repeat(2, 1fr);
  }
}

/* ===== 모바일 ===== */
@media (max-width: 768px) {

  header {
    flex-wrap: wrap;
    padding: 15px 20px;
  }

  nav {
    display: none;
    flex-direction: column;
    width: 100%;
    margin-top: 10px;
  }

  nav a {
    margin: 10px 0;
  }

  .menu-toggle {
    display: block;
  }

  .card-container {
    grid-template-columns: 1fr;
  }

  .section {
    padding: 40px 20px;
  }
}