:root {
  --primary: #6c63ff;
  --secondary: #4caf50;
  --accent: #ff9800;
  --text: #333;
  --bg-light: #f8f9fa;
  --bg-dark: #343a40;
  --success: #28a745;
  --danger: #dc3545;
  --warning: #ffc107;
  --card-shadow: 0 10px 25px rgba(0,0,0,0.1);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  transition: all 0.3s ease;
}

body {
  font-family: 'Segoe UI', sans-serif;
  background: linear-gradient(135deg, #667eea, #764ba2);
  margin: 0;
  padding: 20px;
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  color: var(--text);
}

.container {
  background: rgba(255, 255, 255, 0.95);
  padding: 30px;
  border-radius: 24px;
  box-shadow: var(--card-shadow);
  width: 90%;
  max-width: 450px;
  text-align: center;
  backdrop-filter: blur(10px);
  transform: translateY(0);
  animation: fadeInUp 0.8s ease;
}

h1 {
  margin-bottom: 25px;
  color: var(--primary);
  font-size: 2rem;
  font-weight: 700;
  text-shadow: 0 2px 4px rgba(0,0,0,0.1);
  position: relative;
  padding-bottom: 15px;
}

h1::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 100px;
  height: 4px;
  background: linear-gradient(90deg, var(--primary), var(--accent));
  border-radius: 2px;
}

.input-group {
  margin: 20px 0;
  position: relative;
}

.input-group label {
  display: block;
  text-align: left;
  margin-bottom: 8px;
  font-weight: 600;
  color: var(--text);
  font-size: 0.9rem;
}

.input-group select,
.input-group input {
  width: 100%;
  padding: 14px 20px;
  font-size: 16px;
  border: 2px solid #e0e0e0;
  border-radius: 12px;
  background-color: white;
  box-shadow: 0 2px 5px rgba(0,0,0,0.05);
}

.input-group select:focus,
.input-group input:focus {
  border-color: var(--primary);
  outline: none;
  box-shadow: 0 0 0 3px rgba(108, 99, 255, 0.25);
}

.input-group select {
  cursor: pointer;
  appearance: none;
  background-image: url("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='24' height='24' viewBox='0 0 24 24' fill='none' stroke='%23333' stroke-width='2' stroke-linecap='round' stroke-linejoin='round'%3E%3Cpolyline points='6 9 12 15 18 9'%3E%3C/polyline%3E%3C/svg%3E");
  background-repeat: no-repeat;
  background-position: right 15px center;
  background-size: 16px;
  padding-right: 40px;
}

.rupiah-prefix {
  position: absolute;
  left: 15px;
  top: 41px;
  font-weight: bold;
  color: #666;
}

.rupiah-input {
  padding-left: 45px !important;
}

.quick-buttons {
  margin: 15px 0;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
  justify-content: center;
}

.quick-buttons button {
  padding: 10px 15px;
  font-size: 14px;
  border: none;
  background: var(--secondary);
  color: white;
  border-radius: 50px;
  cursor: pointer;
  font-weight: 600;
  box-shadow: 0 3px 6px rgba(0,0,0,0.1);
  display: flex;
  align-items: center;
  gap: 5px;
}

.quick-buttons button:hover {
  background: #45a049;
  transform: translateY(-2px);
  box-shadow: 0 5px 10px rgba(0,0,0,0.15);
}

#hasil {
  margin-top: 30px;
  padding: 20px;
  font-size: 18px;
  font-weight: bold;
  color: var(--primary);
  background-color: rgba(108, 99, 255, 0.05);
  border-radius: 16px;
  border-left: 5px solid var(--primary);
  text-align: left;
  min-height: 80px;
  display: flex;
  flex-direction: column;
  justify-content: center;
}

#hasil.success {
  border-left: 5px solid var(--success);
  background-color: rgba(40, 167, 69, 0.05);
}

#hasil.warning {
  border-left: 5px solid var(--warning);
  background-color: rgba(255, 193, 7, 0.05);
}

#hasil.error {
  border-left: 5px solid var(--danger);
  background-color: rgba(220, 53, 69, 0.05);
}

#hasil .kembalian-title {
  font-size: 0.9rem;
  color: #666;
  margin-bottom: 5px;
}

#hasil .kembalian-amount {
  font-size: 1.8rem;
  color: var(--primary);
}

#hasil .error-message {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--danger);
}

#hasil .warning-message {
  display: flex;
  align-items: center;
  gap: 10px;
  color: var(--warning);
}

.icon-glow {
  animation: glow 1.5s infinite alternate;
}

@keyframes fadeInUp {
  from {
    opacity: 0;
    transform: translateY(30px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes glow {
  from {
    text-shadow: 0 0 5px rgba(108, 99, 255, 0.5);
  }
  to {
    text-shadow: 0 0 20px rgba(108, 99, 255, 0.8);
  }
}

@keyframes pulse {
  0% {
    transform: scale(1);
  }
  50% {
    transform: scale(1.05);
  }
  100% {
    transform: scale(1);
  }
}

.header-icon {
  display: flex;
  justify-content: center;
  margin-bottom: 15px;
}

.header-icon i {
  font-size: 2.5rem;
  color: var(--primary);
  background: rgba(108, 99, 255, 0.1);
  width: 70px;
  height: 70px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  box-shadow: 0 4px 10px rgba(108, 99, 255, 0.2);
  animation: pulse 2s infinite;
}

.empty-result {
  color: #999;
  font-style: italic;
  font-size: 0.9rem;
  text-align: center;
}

@media (max-width: 480px) {
  .container {
    padding: 20px;
    width: 95%;
  }
  
  h1 {
    font-size: 1.7rem;
  }
}