.btn-fill-up {
  position: relative;
  display: inline-block;
  background: transparent;
  border: 2px solid #198754;
  color: #198754;
  font-weight: 700;
  cursor: pointer;
  overflow: hidden;
  padding: 0.5rem 1.5rem;
  transition: color 1s ease-in-out, background-color 1s ease-in-out;
}

.btn-fill-up .filled {
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 0;
  background-color: #198754;
  z-index: 0;
  transition: height 1s ease-in-out;
}

.btn-fill-up:hover .filled {
  height: 100%;
}

.btn-fill-up .btn-text {
  position: relative;
  z-index: 2;
  transition: color 1s ease-in-out;
}

body.dark-mode {
  background-color: rgb(8, 9, 10) !important;
  color: #eee;
}

body.dark-mode footer {
  background-color: #000 !important;
  color: #aaa;
}

body.dark-mode input#searchInput {
  background-color: #222;
  color: #eee;
  border-color: #198754;
}

body.dark-mode input#searchInput::placeholder {
  color: #8f8f8f;
  opacity: 1;
}

body.dark-mode .btn-fill-up:hover .btn-text {
  color: #000;
}

body.dark-mode #results .list-group-item {
  background-color: #111 !important;
  color: #eee;
  border-color: #333;
}

body.dark-mode #results .btn-outline-success {
  border-color: #eee;
  color: #eee;
}

.neon-underline {
  position: relative;
  color: white;
  display: inline-block;
  font-weight: 600;
  padding-bottom: 6px;
}

.neon-underline::after {
  content: '';
  position: absolute;
  left: 50%;
  bottom: 0;
  width: 60%;
  height: 2px;
  background: #6a00ff;
  border-radius: 1px;
  transform: translateX(-50%);
  box-shadow:
    0 0 4px #6a00ff88,
    0 0 6px #6a00ff77,
    0 0 10px #a366ff55;
  animation: neonGlow 2.5s ease-in-out infinite alternate;
}

@keyframes neonGlow {
  from {
    box-shadow:
      0 0 2px #6a00ff66,
      0 0 4px #6a00ff55,
      0 0 6px #a366ff44;
  }

  to {
    box-shadow:
      0 0 6px #6a00ff88,
      0 0 10px #6a00ff77,
      0 0 14px #a366ff55;
  }
}