::-webkit-inner-spin-button {
  display: none;
}

body {
  font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
  background: linear-gradient(rgba(0, 0, 0, 0.4), rgba(0, 0, 0, 0.5)), url(picture/background.png) no-repeat center / cover;
  backdrop-filter: blur(2pt);
  display: flex;
  flex-direction: column;
  gap: 1rem;
  justify-content: center;
  align-items: center;
  height: 100vh;
  margin: 0;
}


.container {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.18);
  backdrop-filter: blur(60px) saturate(180%);
  -webkit-backdrop-filter: blur(60px) saturate(180%);
  border-radius: 30px;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
  min-width: 400px;
  color: #1f2937;
  backdrop-filter: blur(20px);
  padding: 80px;
  display: block;
}
.main-btn-box{
  display: flex;
  justify-content: center;
  gap: 20px;
}
.container h1 {
  margin-bottom: 1rem;
  color: #f0f0f0;
}

.container button {
  display: flex;
  justify-content: center;
  align-items: center;
  font-size: 15px;
  width:90px;
  height:90px;
  border-radius:50%;
  background:radial-gradient(circle at 30% 30%,rgba(255,255,255,.45),rgba(255,255,255,.18) 40%,rgba(120,180,255,.22) 70%,rgba(120,180,255,.14));
  border:1px solid rgba(255,255,255,.4);
  backdrop-filter:blur(10px);
  box-shadow:inset 0 1px 1px rgba(255,255,255,.5),0 6px 18px rgba(0,0,0,.35);
  color:#fff;
  transition:transform .25s ease,box-shadow .25s ease,background .25s ease;
}

.container button:hover {
  transform:translateY(-4px) scale(1.06);
  background:radial-gradient(circle at 30% 30%,rgba(255,255,255,.55),rgba(255,255,255,.22) 40%,rgba(140,195,255,.28) 70%,rgba(140,195,255,.18));
  box-shadow:inset 0 1px 1px rgba(255,255,255,.6),0 10px 28px rgba(0,0,0,.45);
}

form {
  border: 1px solid rgba(255, 255, 255, 0.18);
  backdrop-filter: blur(60px) saturate(180%);
  -webkit-backdrop-filter: blur(60px) saturate(180%);
  border-radius: 30px;
  box-shadow: 0 8px 32px rgba(0, 0, 0, 0.4);
  padding: 30px 40px;
  border-radius: 12px;
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.7);
  flex-direction: column;
  gap: 20px;
  width: 300px;
  display: flex;
  position: relative;
}
input[type="text"],#numberA,#numberB,#oddEvenCheck{
  padding: 12px 16px;
  border-radius: 18px;
  border: 1px solid rgba(255, 255, 255, 0.2);
  outline: none;
  font-size: 16px;
  box-sizing: border-box;
  background: rgba(255, 255, 255, 0.08);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  color: white;
}

input[type="text"],#numberA,#numberB,#oddEvenCheck::placeholder {
  color: rgba(255, 255, 255, 0.5);
}

input[type="text"],#numberA,#numberB,#oddEvenCheck:focus {
  border-color: rgba(0, 123, 255, 0.6);
  background: rgba(255, 255, 255, 0.12);
  box-shadow: 0 0 0 3px rgba(0, 123, 255, 0.2);
}
#formSwap,
#formPalindrome,
#formOddEven {
  display: none;
}

.back {
  text-decoration: none;
  position: absolute;
  right: 2%;
  top: 3%;
  font-size: 20px;
  color: #bbb;
  text-transform: uppercase;
  transition: 0.3s;
}

.back:hover {
  color: #0d6efd;
}

h1 {
  text-align: center;
  font-size: 26px;
  color: #fff;
  margin: 0;
}

.mssg,
.mssgOE {
  text-align: center;
  text-transform: uppercase;
  letter-spacing: 5px;
  display: none;
  font-weight: bold;
  font-size: 16px;
}

.green {
  color: #28a745;
}

.red {
  color: #dc3545;
}

input {
  padding: 10px;
  font-size: 16px;
  border-radius: 8px;
  border: 1px solid #555;
  background-color: #2c2c2c;
  color: #fff;
  outline: none;
  transition: border-color 0.3s, box-shadow 0.3s;
}

input:focus {
  border-color: #0d6efd;
  box-shadow: 0 0 5px rgba(13, 110, 253, 0.5);
}

button {
  padding: 12px;
  font-size: 16px;
  background-color: #0d6efd;
  color: white;
  border: none;
  border-radius: 8px;
  cursor: pointer;
  transition: all 0.3s ease;
}

button:hover {
  background-color: #0056b3;
  transform: scale(1.05);
}

button:disabled {
  background: #062f5a5b;
  cursor: not-allowed;
}

#numberA {
  color: #0d6efd;
}

#numberB {
  color: #d63384;
}

#numberA.swapped {
  color: #d63384;
}

#numberB.swapped {
  color: #0d6efd;
}

.error {
  border-color: #dc3545;
  animation: shake 0.5s linear infinite;
}

@keyframes shake {
  0% { transform: translateX(0); }
  25% { transform: translateX(-5px); }
  50% { transform: translateX(0); }
  75% { transform: translateX(5px); }
  100% { transform: translateX(0); }
}

#copyRight {
  color: #bbb;
  text-align: center;
  margin: 0;
  font-size: 0.8rem;
  user-select: none;
}