body {
  margin: 0;
  font-family: 'Georgia', serif;
  color: #1a1a2e;
  background: #fff;
}
nav {
  display: flex;
  justify-content: center;
  gap: 30px;
  padding: 18px;
  background: #fff;
  border-bottom: 1px solid #eee;
  font-family: Arial, sans-serif;
}
nav a {
  text-decoration: none;
  color: #1a1a2e;
  font-weight: bold;
}
nav a.active {
  color: #16537e;
  border-bottom: 2px solid #16537e;
}
.banner {
  background: linear-gradient(135deg, #0b1035, #1a1a4e, #2a2a6e);
  color: white;
  text-align: center;
  padding: 100px 20px;
}
.banner h1 {
  font-size: 3em;
  margin: 0;
}
.welcome {
  max-width: 800px;
  margin: 40px auto;
  text-align: justify;
  font-style: italic;
  font-size: 1.1em;
  padding: 0 20px;
}
.profile {
  display: flex;
  gap: 30px;
  max-width: 800px;
  margin: 40px auto;
  padding: 0 20px;
  align-items: center;
}
.profile img {
  width: 220px;
  border-radius: 6px;
}
.quick-links {
  max-width: 800px;
  margin: 40px auto;
  padding: 0 20px;
}
.quick-links h2 {
  font-size: 1.3em;
  margin-bottom: 10px;
}
.horizontal-links {
  display: flex;
  flex-wrap: wrap;
  gap: 20px;
  list-style: none;
  padding: 0;
  margin: 0;
  line-height: normal;
}
.content {
  max-width: 800px;
  margin: 40px auto;
  padding: 0 20px;
}
details {
  margin-bottom: 15px;
  border: 1px solid #ddd;
  border-radius: 6px;
  padding: 10px 15px;
}
summary {
  font-weight: bold;
  cursor: pointer;
  font-size: 1.1em;
}
details details {
  margin-top: 10px;
  border: none;
  border-left: 3px solid #eee;
  padding-left: 15px;
}
ul { line-height: 1.8; }
a { color: #16537e; }

table {
  border-collapse: collapse;
  width: 100%;
  margin: 15px 0;
  font-family: Arial, sans-serif;
  font-size: 0.95em;
}
th, td {
  border: 1px solid #ddd;
  padding: 8px 12px;
  text-align: left;
  vertical-align: top;
}
th {
  background: #16537e;
  color: white;
}
tr:nth-child(even) {
  background: #f7f7f7;
}

.unit-block {
  margin: 20px 0;
  padding-bottom: 15px;
  border-bottom: 1px solid #eee;
}
.unit-block h3 {
  margin-bottom: 5px;
}
.unit-block p {
  text-align: justify;
}
.print-btn {
  display: inline-block;
  margin: 10px 0 5px 0;
  padding: 6px 14px;
  background: #16537e;
  color: white;
  border: none;
  border-radius: 5px;
  font-family: Arial, sans-serif;
  font-size: 0.85em;
  cursor: pointer;
}
.print-btn:hover {
  background: #103d5e;
}

/* ---- Semester Tabs ---- */
.tabs {
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  max-width: 800px;
  margin: 30px auto 0;
  padding: 0 20px;
  font-family: Arial, sans-serif;
}
.tab-btn {
  padding: 8px 16px;
  border: 1px solid #ddd;
  border-radius: 20px;
  background: #fff;
  color: #1a1a2e;
  font-weight: bold;
  font-size: 0.9em;
  cursor: pointer;
}
.tab-btn:hover {
  background: #f2f2f2;
}
.tab-btn.active {
  background: #16537e;
  color: #fff;
  border-color: #16537e;
}

.tab-content {
  display: none;
  max-width: 800px;
  margin: 20px auto 0;
  padding: 0 20px;
}
.tab-content.active {
  display: block;
}

@media print {
  nav, .print-btn { display: none; }
  .banner { background: none; color: #1a1a2e; padding: 20px 0; }
  details { border: none; padding: 0; }
  summary { display: none; }
  details > *:not(summary) { display: block !important; }

  .tabs { display: none; }
  .tab-content { display: none !important; }
  .tab-content.active { display: block !important; }
}