body {
  margin: 0;
  font-family: 'Share Tech Mono', monospace;
  background-color: #0d0d0d;
  color: #e0e0e0;
  text-align: center;
}

h1 {
  color: #ff0000;
  text-shadow: 0 0 0.625rem #fa2727;
  font-size: 2.5rem;
  margin-top: 3.75rem;
}

button {
  background-color: #ff0000;
  color: #0d0d0d;
  border: none;
  padding: 0.625rem 1.25rem;
  font-size: 1rem;
  margin-top: 1.25rem;
  cursor: pointer;
  border-radius: 0.5rem;
  box-shadow: 0 0 0.625rem #ff0000;
  transition: background-color 0.3s ease;
}

button:hover {
  background-color: #e60000;
}
#tsparticles {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: -1;
}
.navbar {
  position: fixed;
  top: 0;
  width: 100%;
  background-color: #0d0d0d;
  box-shadow: 0 0 0.625rem #ff0000;
  z-index: 1000;
}

.navbar ul {
  display: flex;
  justify-content: center;
  list-style: none;
  padding: 0.625rem;
  margin: 0;
}

.navbar li {
  margin: 0 0.9375rem;
}

.navbar a {
  color: #ff0000;
  text-decoration: none;
  font-family: 'Share Tech Mono', monospace;
  font-size: 1.1rem;
  transition: color 0.3s ease;
  position: relative;
  display: inline-block;
  padding: 0.125rem 0.25rem;
  transition: color 0.25s ease, transform 0.18s ease;
  will-change: color, transform;
}

.navbar a::after {
  content: "";
  position: absolute;
  left: 50%;
  bottom: -0.3125rem;
  width: 60%;
  height: 2px;
  background: #ff0000;
  transform: translateX(-50%) scaleX(0);
  transform-origin: center;
  transition: transform 0.25s ease;
  border-radius: 2px;
}

.navbar a:hover,
.navbar a:focus {
  color: #ffffff;
  transform: translateY(-0.1875rem);
}

.navbar a:hover::after,
.navbar a:focus::after {
  transform: translateX(-50%) scaleX(1);
}
html {
  scroll-behavior: smooth;
}

/* responsive / mobile improvements */
html { font-size: 16px; }
.intro {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  min-height: calc(100vh - 3.5rem);
  padding: 1.25rem;
  box-sizing: border-box;
  gap: 0.75rem;
  
}
.intro h1 {
  font-size: clamp(1.5rem, 6vw, 2.5rem);
  margin-top: 0;
  line-height: 1.05;
}
.intro p {
  font-size: clamp(0.9rem, 3.2vw, 1.1rem);
  margin: 0;
  opacity: 0.95;
}

/* improve tap targets and readability */
button {
  min-height: 2.75rem;
  min-width: 3rem;
  padding: 0.625rem 1.25rem;
  font-size: clamp(0.95rem, 3.5vw, 1rem);
}

.navbar {
  padding: 0.25rem 0;
    
}
.navbar ul {
  gap: 0.5rem;
}

/* keyboard and focus accessibility */
a:focus, button:focus {
  outline: 3px solid rgba(255, 0, 0, 0.6);
  outline-offset: 3px;
}

/* reduce motion for users who prefer it */
@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.001ms !important;
    transition-duration: 0.001ms !important;
    scroll-behavior: auto;
  }
}

/* mobile layout: move navbar to bottom and increase sizes */
@media (max-width: 600px) {
  .navbar {
    position: fixed;
    top: auto;
    bottom: 0;
    left: 0;
    width: 100%;
    background-color: rgba(13, 13, 13, 0.96);
    box-shadow: 0 -0.5rem 1.125rem rgba(255, 0, 0, 0.12);
    z-index: 1000;
  }
  .navbar ul {
    display: flex;
    justify-content: space-around;
    padding: 0.5rem;
    margin: 0;
  }
  .navbar a {
    font-size: 1rem;
    padding: 0.5rem 0.75rem;
    display: block;
    min-height: 2.75rem;
    min-width: 3.5rem;
    line-height: 1.1;
  }
  .intro {
    min-height: calc(100vh - 4.25rem);
    padding-bottom: 4.75rem; /* ensure content not hidden behind navbar */
  }
  button {
    width: min(90%, 420px);
  }
}

/* ensure content order for screen readers */
.intro, .navbar { -webkit-tap-highlight-color: transparent; }
.btn{
  background-color: #ff0000;
  color: #0d0d0d;
  border: none;
  padding: 0.325rem 0.75rem;
  font-size: 1rem;
  margin-top: 1.25rem;
  cursor: pointer;
  border-radius: 0.5rem;
  box-shadow: 0 0 0.625rem #ff0000;
  transition: background-color 0.3s ease;
}
.btn:hover {
  background-color: #e60000;
}