.btn-glow-border {
  position: relative;
  border: none !important; 
  overflow: hidden;
  transition: 0.3s;
  background-color: transparent; /* Διάφανο φόντο */
  color: #fff !important; 
  padding: 15px 30px;
}

.btn-glow-border:hover {
  font-weight: bold;
  background-color: transparent;
  box-shadow: 0 0 15px rgba(0, 255, 255, 0.4);
}

.btn-glow-border span {
  position: absolute;
  display: block;
  filter: blur(5px);
}

.btn-glow-border span:nth-child(1),
.btn-glow-border span:nth-child(2),
.btn-glow-border span:nth-child(3),
.btn-glow-border span:nth-child(4) {
    background: linear-gradient(
        45deg, 
        #ff0000, #ff7300, #ffeb00, #00ff00, 
        #00ffff, #002bff, #ff00c8, #ff0000
    );
    background-size: 400%;
    animation: glowing 20s linear infinite;
}

@keyframes glowing {
    0% { background-position: 0 0; }
    50% { background-position: 400% 0; }
    100% { background-position: 0 0; }
}

/* Animation για την πάνω γραμμή */
.btn-glow-border span:nth-child(1) {
  top: 0;
  left: -100%;
  width: 100%;
  height: 14px;
  animation: animate1 1.5s linear infinite, glowing 20s linear infinite;
}

@keyframes animate1 {
  0% { left: -100%; }
  50%, 100% { left: 100%; }
}

/* Animation για τη δεξιά γραμμή */
.btn-glow-border span:nth-child(2) {
  top: -100%;
  right: 0;
  width: 14px;
  height: 100%;
  animation: animate2 1.5s linear infinite, glowing 20s linear infinite;
  animation-delay: 0.375s;
}

@keyframes animate2 {
  0% { top: -100%; }
  50%, 100% { top: 100%; }
}

/* Animation για την κάτω γραμμή */
.btn-glow-border span:nth-child(3) {
  bottom: 0;
  right: -100%;
  width: 100%;
  height: 18px;
  animation: animate3 1.5s linear infinite, glowing 20s linear infinite;
  animation-delay: 0.75s;
}

@keyframes animate3 {
  0% { right: -100%; }
  50%, 100% { right: 100%; }
}

/* Animation για την αριστερή γραμμή */
.btn-glow-border span:nth-child(4) {
  bottom: -100%;
  left: 0;
  width: 18px;
  height: 100%;
  animation: animate4 1.5s linear infinite, glowing 20s linear infinite;
  animation-delay: 1.125s;
}

@keyframes animate4 {
  0% { bottom: -100%; }
  50%, 100% { bottom: 100%; }
}