*, *::before, *::after {
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  font-family: 'Roboto', sans-serif;
  background: #0a0a0a;
  color: #fff;
  overflow-x: hidden;
}

/* === Sticky Top Nav === */
.top-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1px 20px;
  background-color: rgba(0, 0, 0, 0.4);
  backdrop-filter: blur(8px);
  position: sticky;
  top: 0;
  z-index: 1000;
  border-bottom: 1px solid #222;
}

.logo {
  height: 80px;
  width: auto;
}

.logo-link {
  display: flex;
  align-items: center;
  text-decoration: none;
}

.cta-top {
  background: #e62429;
  color: white;
  padding: 10px 20px;
  border-radius: 6px;
  text-decoration: none;
  font-size: 0.95rem;
  font-weight: bold;
  transition: background 0.3s ease;
}

.cta-top:hover {
  background: #ff3b3b;
}

/* === Homepage Header === */
.homepage-header {
  background: linear-gradient(135deg, #1a1a1a, #000);
  background-image: url('https://www.transparenttextures.com/patterns/dark-mosaic.png');
  padding: 100px 10px;
  text-align: center;
  display: flex;
  justify-content: center;
}

.header-content {
  max-width: 640px;
  width: 100%;
  padding: 0 10px;
  text-align: center;
  display: inline-block;
}

.homepage-header h1 {
  font-family: 'Orbitron', sans-serif;
  font-size: 3rem;
  color: #e62429;
  margin: 0;
  white-space: nowrap;
}

.homepage-header p {
  font-size: 1.2rem;
  max-width: 600px;
  margin: 20px auto 0;
  color: #ccc;
}

/* === Simple Header for Other Pages === */
.simple-header {
  padding: 60px 20px;
  text-align: center;
}

.simple-header h1 {
  font-family: 'Orbitron', sans-serif;
  margin-bottom: 20px;
  font-size: 2.5rem;
  color: #e62429;
}

.simple-header p {
  font-size: 1.2rem;
  color: #ccc;
  max-width: 800px;
  margin: 0 auto;
}

/* === Buttons === */
.cta-button {
  background: #e62429;
  border: none;
  padding: 15px 30px;
  font-size: 1.1rem;
  color: white;
  border-radius: 8px;
  cursor: pointer;
  text-decoration: none;
  transition: background 0.3s;
  display: inline-block;
  margin-top: 20px;
}

.cta-button:hover {
  background: #ff3b3b;
}

/* === Sections === */
section {
  padding: 60px 20px;
  max-width: 800px;
  margin: 0 auto;
  text-align: center;
}

section ul {
  text-align: left;
  max-width: 600px;
  margin: 0 auto 2rem auto;
  padding-left: 1.2rem;
}

section ul li a {
  text-decoration: none;
  color: #e62429;
}

section ul li a:hover {
  text-decoration: underline;
}

h2 {
  font-family: 'Orbitron', sans-serif;
  font-size: 2rem;
  color: #ff3b3b;
  margin-bottom: 20px;
  text-align: center;
}

/* === Video Container === */
.video-container {
  width: 100%;
  max-width: 640px;
  margin: 20px auto;
  aspect-ratio: 16 / 9;
}

.video-container iframe {
  width: 100%;
  height: 100%;
  border: none;
}

/* === Footer === */
footer {
  text-align: center;
  padding: 30px 10px;
  font-size: 0.9rem;
  background: #111;
  color: #777;
}

/* === PDF Download Button === */
.download-pdf {
  display: inline-block;
  padding: 16px 24px;
  margin: 20px auto;
  font-size: 1.1rem;
  font-weight: bold;
  color: #fff;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.1);
  backdrop-filter: blur(10px);
  border-radius: 12px;
  text-decoration: none;
  box-shadow: 0 0 15px rgba(230, 36, 41, 0.3);
  transition: background 0.3s, transform 0.3s, box-shadow 0.3s;
  text-align: center;
}

.download-pdf:hover {
  background: rgba(255, 255, 255, 0.1);
  transform: translateY(-2px);
  box-shadow: 0 0 20px rgba(255, 59, 59, 0.5);
}

/* === Floating Equations === */
@keyframes floatEquations {
  0% { transform: translateY(0) translateX(0); opacity: 0; }
  50% { opacity: 0.6; }
  100% { transform: translateY(-1000px) translateX(200px); opacity: 0; }
}

.equation {
  position: fixed;
  font-family: 'Courier New', monospace;
  font-size: 1rem;
  color: rgba(255, 255, 255, 0.1);
  animation: floatEquations 30s linear infinite;
  pointer-events: none;
}

/* === Mobile Styles === */
@media (max-width: 600px) {
  .homepage-header {
    padding: 80px 5px;
  }

  .homepage-header h1 {
    font-size: 2.5rem;
  }

  .homepage-header p {
    font-size: 1rem;
    max-width: 100%;
  }

  .header-content {
    padding: 0 5px;
  }

  .cta-top {
    font-size: 0.8rem;
    padding: 8px 14px;
  }

  .logo {
    height: 60px;
  }
}

/* === Dropdown Menu === */
.dropdown {
  position: relative;
  display: inline-block;
}

.dropbtn {
  background: #e62429;
  color: white;
  padding: 10px 20px;
  border: none;
  border-radius: 6px;
  font-size: 0.95rem;
  font-weight: bold;
  cursor: pointer;
}

.dropbtn:hover {
  background: #ff3b3b;
}

.dropdown-content {
  display: none; /* Hidden by default */
  position: absolute;
  right: 0;
  background-color: #111;
  min-width: 200px;
  border-radius: 6px;
  overflow: hidden;
  box-shadow: 0px 8px 16px rgba(0,0,0,0.3);
  z-index: 1;
}

/* Show only when toggled with JavaScript */
.dropdown-content.show {
  display: block;
}

.dropdown-content a {
  color: white;
  padding: 12px 16px;
  text-decoration: none;
  display: block;
}

.dropdown-content a:hover {
  background-color: #222;
}