:root {
  --gold: #f8c471;
  --teal: #4fd1c5;
  --text: #fff;
  --glass: rgba(0, 0, 0, 0.55);
}

body {
  font-family: "Segoe UI", Arial, sans-serif;
  margin: 0;
  padding: 0;
  color: var(--text);
  background: black;
  overflow-x: hidden;
}

/* === Background === */
.video-container {
  position: fixed;
  top: 0; left: 0;
  width: 100%; height: 100%;
  z-index: -1;
}
.video-container video {
  width: 100%;
  height: 100%;
  object-fit: cover;
}
.video-container::before {
  content: "";
  position: absolute;
  inset: 0;
  background: linear-gradient(120deg, rgba(0,0,0,0.92), rgba(0,0,0,0.75));
}

/* === Navbar === */
.navbar {
  position: fixed;
  top: 0;
  width: 100%;
  background: var(--glass);
  backdrop-filter: blur(10px);
  padding: 15px 0;
  display: flex;
  justify-content: center;
  align-items: center;
  gap: 40px;
  z-index: 1000;
  box-shadow: 0 2px 20px rgba(0, 0, 0, 0.6);
}
.navbar a, .navbar .dropbtn {
  color: white;
  font-size: 18px;
  text-decoration: none;
  display: inline-flex;
  align-items: center;
  gap: 8px;
  position: relative;
  transition: all 0.3s ease;
}
.navbar a:hover, .navbar .dropbtn:hover {
  background: linear-gradient(90deg, var(--gold), var(--teal));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}
.navbar a::after, .navbar .dropbtn::after {
  content: "";
  height: 2px;
  background: linear-gradient(90deg, var(--gold), var(--teal));
  width: 0;
  position: absolute;
  bottom: -5px;
  left: 0;
  transition: width 0.3s ease;
}
.navbar a:hover::after, .navbar .dropbtn:hover::after {
  width: 100%;
}

/* Dropdown */
.dropdown { position: relative; }
.dropdown-content {
  display: none;
  position: absolute;
  background: rgba(0, 0, 0, 0.95);
  border-radius: 8px;
  min-width: 160px;
  box-shadow: 0px 8px 16px rgba(0, 0, 0, 0.4);
  z-index: 1000;
}
.dropdown-content a {
  color: white;
  padding: 10px 16px;
  text-decoration: none;
  display: block;
}
.dropdown-content a:hover {
  background: linear-gradient(90deg, rgba(248,196,113,0.25), rgba(79,209,197,0.25));
}
.dropdown:hover .dropdown-content { display: block; }

/* === Sidebar === */
.sidebar {
  position: fixed;
  top: 80px;
  left: 0;
  width: 230px;
  height: calc(100% - 80px);
  background: var(--glass);
  backdrop-filter: blur(8px);
  border-right: 2px solid transparent;
  border-image: linear-gradient(to bottom, var(--gold), var(--teal));
  border-image-slice: 1;
  padding: 25px 15px;
  overflow-y: auto;
}
.sidebar h2 {
  background: linear-gradient(90deg, var(--gold), var(--teal));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  text-align: center;
  margin-bottom: 15px;
}
.sidebar a {
  display: block;
  color: white;
  padding: 10px;
  text-decoration: none;
  border-radius: 6px;
  transition: all 0.3s ease;
}
.sidebar a:hover {
  background: linear-gradient(90deg, rgba(248,196,113,0.15), rgba(79,209,197,0.15));
  box-shadow: 0 0 8px rgba(248,196,113,0.4);
}
.sidebar a.active {
  font-weight: bold;
  background: linear-gradient(90deg, var(--gold), var(--teal));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

/* === Content === */
.content {
  margin-left: 260px;
  padding: 30px 60px;
  background: rgba(0, 0, 0, 0.65);
  border-radius: 15px;
  margin-top: 100px;
  margin-right: 40px;
  box-shadow: 0 0 25px rgba(248,196,113,0.3);
  animation: fadeIn 1.2s ease;
}
h1, h2 {
  background: linear-gradient(90deg, var(--gold), var(--teal));
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  text-align: center;
}
p {
  text-align: justify;
  line-height: 1.7;
  font-size: 18px;
}

/* === Figures === */
figure {
  display: block;
  margin: 30px auto 50px;
  text-align: center;
}
img {
  width: 40%;
  border-radius: 12px;
  border: 1px solid rgba(255,255,255,0.3);
  box-shadow: 0 0 20px rgba(248,196,113,0.2);
  transition: all 0.4s ease-in-out;
  cursor: zoom-in;
}
img:hover {
  transform: scale(1.8);
  z-index: 10;
  box-shadow: 0 0 40px rgba(79,209,197,0.7);
  border-color: var(--teal);
}
figcaption {
  font-size: 15px;
  color: #ddd;
  margin-top: 10px;
}

/* === Section Divider === */
hr {
  border: none;
  height: 2px;
  background: linear-gradient(90deg, var(--gold), var(--teal));
  margin: 40px 0;
  border-radius: 4px;
}

/* === Back to Top === */
#backToTop {
  position: fixed;
  bottom: 25px;
  right: 25px;
  background: linear-gradient(135deg, var(--gold), var(--teal));
  color: black;
  border: none;
  border-radius: 50%;
  width: 50px;
  height: 50px;
  font-size: 22px;
  cursor: pointer;
  box-shadow: 0 0 20px rgba(79,209,197,0.5);
  transition: all 0.3s ease;
  opacity: 0;
  visibility: hidden;
  z-index: 1000;
}
#backToTop:hover {
  transform: scale(1.1);
  box-shadow: 0 0 25px rgba(248,196,113,0.8);
}
#backToTop.show {
  opacity: 1;
  visibility: visible;
}

/* === Footer === */
.footer {
  text-align: center;
  padding: 25px;
  background: rgba(0,0,0,0.7);
  font-size: 16px;
  border-top: 1px solid rgba(255,255,255,0.2);
  box-shadow: 0 -2px 20px rgba(0,0,0,0.5);
}
.footer a {
  color: var(--teal);
  text-decoration: none;
}
.footer a:hover {
  color: var(--gold);
  text-shadow: 0 0 10px var(--gold), 0 0 20px var(--teal);
}

/* === Animation === */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(20px); }
  to { opacity: 1; transform: translateY(0); }
}

/* === Responsive === */
@media (max-width: 900px) {
  .sidebar {
    position: relative;
    width: 100%;
    height: auto;
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
  }
  .content {
    margin-left: 0;
    margin-right: 0;
    padding: 25px;
  }
  img {
    width: 80%;
    transform: none;
  }
  img:hover {
    transform: none;
  }
}