html, body {
  margin: 0;
  padding: 0;
  height: 100%;
  background: #000;
  color: #fff;
  font-family: 'Segoe UI', Verdana, Arial, sans-serif;
  font-size: 15px;
  line-height: 1.6;
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  opacity: 0;
  animation: fadeIn 0.6s ease-out forwards;
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

header {
  background: linear-gradient(to bottom, #222, #111);
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.6);
  padding: 15px 20px;
  display: flex;
  justify-content: center;
}

.header-center {
  display: flex;
  flex-direction: column;
  align-items: center;
}

.main-logo {
  max-height: 100px;
  filter: drop-shadow(0 2px 4px rgba(0, 0, 0, 0.5));
  transition: transform 0.3s ease;
}
.main-logo:hover { transform: scale(1.03); }

.motto {
  max-height: 40px;
  margin-top: 8px;
  opacity: 0.9;
}

.layout {
  flex: 1;
  display: flex;
  min-height: 0;
}

nav {
  background: linear-gradient(to bottom, #222, #111);
  width: 200px;
  padding: 25px 20px;
  border-right: 2px solid #333;
  box-shadow: inset -2px 0 6px rgba(0, 0, 0, 0.4);
  display: flex;
  flex-direction: column;
}

.nav-list {
  list-style: none;
  margin: 0;
  padding: 0;
  flex-grow: 1;
}

.nav-list li {
  margin-bottom: 12px;
}

.nav-list a {
  display: block;
  padding: 10px 14px;
  background: #333;
  border: 1px solid #444;
  border-radius: 6px;
  font-family: "Courier New", monospace;
  font-size: 14px;
  color: #99ccff;
  text-decoration: none;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.4);
  transition: background 0.25s, border-color 0.25s, transform 0.25s, box-shadow 0.25s;
}

.nav-list a:hover {
  background: #444;
  border-color: #66aaff;
  color: #66aaff;
  transform: translateY(-2px);
  box-shadow: 0 4px 10px rgba(0, 0, 0, 0.5);
}

main {
  flex: 1;
  background: #000;
  padding: 30px;
  overflow-y: auto;
}

main h1 {
  font-size: 28px;
  margin-top: 0;
  margin-bottom: 20px;
  text-shadow: 0 2px 6px rgba(0, 0, 0, 0.7);
  font-family: "Courier New", monospace;
  color: #99ccff;
}

main a {
  color: #00ccff;
  text-decoration: none;
}
main a:hover {
  text-decoration: underline;
}