body {
  font-family: 'Montserrat', sans-serif;
  background: linear-gradient(135deg, #000000, #111111);
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
  margin: 0;
}

.container {
  background: linear-gradient(145deg, #111, #1c1c1c);
  padding: 40px 30px;
  border-radius: 25px;
  box-shadow: 0 20px 60px rgba(0,0,0,0.8);
  text-align: center;
  width: 95%;
  max-width: 450px;
}

h1 {
  margin-bottom: 20px;
  font-weight: 600;
  font-size: 2rem;
  background: linear-gradient(90deg, #ffffff, #bbbbbb);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.tabs {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  margin-bottom: 20px;
}

.tab-btn {
  background: #1a1a1a;
  border: none;
  padding: 10px 15px;
  margin: 3px;
  border-radius: 15px;
  cursor: pointer;
  font-weight: 600;
  color: #fff;
  box-shadow: 0 4px 12px rgba(0,0,0,0.5);
  transition: all 0.3s ease;
}

.tab-btn.active, .tab-btn:hover {
  background: linear-gradient(90deg, #ffffff, #cccccc);
  color: #000;
  transform: scale(1.05);
}

.input-container {
  display: flex;
  align-items: center;
  gap: 10px;
  margin-bottom: 15px;
  flex-direction: column;
}

input {
  padding: 14px;
  border-radius: 15px;
  border: 1px solid #333;
  font-size: 1rem;
  background: #111;
  color: #fff;
  width: 100%;
  box-sizing: border-box;
  box-shadow: 0 0 8px rgba(255,255,255,0.1), 0 0 15px rgba(255,255,255,0.05);
  transition: all 0.3s ease;
}

input:focus {
  outline: none;
  box-shadow: 0 0 12px rgba(255,255,255,0.3), 0 0 25px rgba(255,255,255,0.2);
}

button#convertBtn {
  margin-top: 10px;
  padding: 14px;
  width: 100%;
  border-radius: 15px;
  border: none;
  background: linear-gradient(135deg, #ffffff, #cccccc);
  color: #000;
  font-weight: 600;
  font-size: 1rem;
  cursor: pointer;
  transition: all 0.3s ease;
  box-shadow: 0 0 8px rgba(255,255,255,0.1), 0 0 20px rgba(255,255,255,0.1);
}

button#convertBtn:hover {
  transform: scale(1.05);
  box-shadow: 0 0 12px rgba(255,255,255,0.2), 0 0 25px rgba(255,255,255,0.2);
}

.result {
  margin-top: 20px;
  font-size: 1.2rem;
  font-weight: 600;
  color: #fff;
  background: linear-gradient(90deg, #ffffff, #bbbbbb);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

.custom-dropdown {
  position: relative;
  width: 100%;
  cursor: pointer;
}

.dropdown-selected {
  padding: 14px;
  border-radius: 15px;
  background: linear-gradient(145deg, #111, #222);
  color: #fff;
  box-shadow: 0 0 8px rgba(255,255,255,0.1), 0 0 20px rgba(255,255,255,0.1);
  font-size: 1rem;
  transition: all 0.3s ease;
}

.dropdown-selected:hover {
  box-shadow: 0 0 12px rgba(255,255,255,0.2), 0 0 25px rgba(255,255,255,0.15);
}

.dropdown-items {
  position: absolute;
  width: 100%;
  max-height: 220px;
  overflow-y: auto;
  background: linear-gradient(145deg, #111, #1a1a1a);
  border-radius: 15px;
  box-shadow: 0 8px 20px rgba(0,0,0,0.3);
  top: 55px;
  left: 0;
  z-index: 10;
  padding: 10px 0;
  display: none;
}

.dropdown-items.show { display: block; }
.dropdown-items div { padding: 12px 14px; border-bottom: 1px solid #333; color: #fff; cursor: pointer; border-radius: 10px; transition: all 0.2s ease; }
.dropdown-items div:hover { background: linear-gradient(90deg, #222, #333); }
.dropdown-items::-webkit-scrollbar { width:0; background:transparent; }
.dropdown-items { scrollbar-width: none; -ms-overflow-style: none; }

.message { margin-top: 10px; padding: 10px; border-radius: 12px; background: linear-gradient(145deg, #ff4b4b, #ff0000); color: #fff; font-weight: 600; display: none; text-align: center; transition: all 0.3s ease; }

/* ------------------------- */
/* Custom Number Input Arrows */
/* ------------------------- */
input[type=number]::-webkit-inner-spin-button,
input[type=number]::-webkit-outer-spin-button {
  -webkit-appearance: none; /* Remove default arrows in Chrome/Safari/Edge */
  margin: 0;
}

input[type=number] {
  -moz-appearance: textfield; /* Remove default arrows in Firefox */
}