:root {
  --bg-color: #0d0d0d;
  --card-bg: rgba(25, 25, 25, 0.95);
  --accent-gold: #ffd700;
  --accent-green: #00ff88;
  --text-primary: #ffffff;
  --text-secondary: #a0a0a0;
  --danger: #ff4d4d;
  --glass-border: rgba(255, 255, 255, 0.1);
  --shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
}

body {
  background-color: var(--bg-color);
  color: var(--text-primary);
  display: flex;
  justify-content: center;
  align-items: center;
  min-height: 100vh;
  background: radial-gradient(circle at 50% -20%, #1a2e25 0%, #0d0d0d 60%);
  padding: 20px;
}

.app-container {
  width: 100%;
  max-width: 480px;
  background: var(--card-bg);
  backdrop-filter: blur(10px);
  border: 1px solid var(--glass-border);
  border-radius: 24px;
  padding: 32px;
  box-shadow: var(--shadow);
  display: flex;
  flex-direction: column;
  gap: 24px;
  position: relative;
  overflow: hidden;
}

/* Header Section */
header {
  text-align: center;
}

h1 {
  font-size: 1.5rem;
  font-weight: 700;
  background: linear-gradient(135deg, var(--accent-gold), #fff);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  margin-bottom: 8px;
  letter-spacing: -0.5px;
}

.subtitle {
  color: var(--text-secondary);
  font-size: 0.9rem;
}

/* Stats Card */
.stats-card {
  background: rgba(255, 255, 255, 0.03);
  border-radius: 16px;
  padding: 20px;
  border: 1px solid var(--glass-border);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 8px;
  transition: transform 0.2s ease;
}

.stats-card:hover {
  transform: translateY(-2px);
  border-color: rgba(255, 215, 0, 0.3);
}

.day-label {
  font-size: 0.85rem;
  text-transform: uppercase;
  letter-spacing: 1px;
  color: var(--accent-gold);
}

.balance-display {
  font-size: 2.5rem;
  font-weight: 800;
  color: var(--text-primary);
  text-shadow: 0 0 20px rgba(0, 255, 136, 0.1);
}

.balance-subtext {
  font-size: 0.9rem;
  color: var(--text-secondary);
}

.limit-progress {
  width: 100%;
  height: 6px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 3px;
  margin-top: 12px;
  overflow: hidden;
}

.progress-bar {
  height: 100%;
  background: linear-gradient(90deg, var(--accent-gold), var(--accent-green));
  width: 0%;
  transition: width 0.5s ease-out;
}

/* Input Section */
.input-group {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

input {
  width: 100%;
  padding: 16px;
  background: rgba(0, 0, 0, 0.2);
  border: 1px solid var(--glass-border);
  border-radius: 12px;
  color: var(--text-primary);
  font-size: 1rem;
  outline: none;
  transition: all 0.2s;
}

input:focus {
  border-color: var(--accent-gold);
  background: rgba(0, 0, 0, 0.3);
}

input::placeholder {
  color: rgba(255, 255, 255, 0.3);
}

button.primary-btn {
  background: var(--accent-gold);
  color: #000;
  border: none;
  padding: 16px;
  border-radius: 12px;
  font-weight: 700;
  cursor: pointer;
  transition: all 0.2s;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  font-size: 1rem;
}

button.primary-btn:hover {
  transform: translateY(-1px);
  filter: brightness(1.1);
  box-shadow: 0 4px 12px rgba(255, 215, 0, 0.2);
}

button.primary-btn:active {
  transform: translateY(0);
}

button:disabled {
  opacity: 0.5;
  cursor: not-allowed;
  transform: none !important;
}

/* Transaction List */
.transactions {
  flex-grow: 1;
  display: flex;
  flex-direction: column;
  gap: 12px;
  max-height: 240px;
  overflow-y: auto;
  padding-right: 4px;
}

.transactions::-webkit-scrollbar {
  width: 4px;
}

.transactions::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.2);
  border-radius: 2px;
}

.transaction-item {
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 12px 16px;
  background: rgba(255, 255, 255, 0.03);
  border-radius: 10px;
  border: 1px solid transparent;
  animation: slideIn 0.3s ease-out;
}

.transaction-item:hover {
  border-color: rgba(255, 255, 255, 0.1);
  background: rgba(255, 255, 255, 0.05);
}

.item-desc {
  font-weight: 500;
}

.item-price {
  color: var(--accent-green);
  font-weight: 600;
}

.empty-state {
  text-align: center;
  color: var(--text-secondary);
  font-style: italic;
  padding: 20px;
  font-size: 0.9rem;
}

/* Next Day Button */
.next-day-btn {
  background: var(--bg-color); /* To cover content if it sticks */
  border: 1px solid var(--accent-green);
  color: var(--accent-green);
  padding: 16px;
  border-radius: 12px;
  font-weight: 700;
  cursor: pointer;
  width: 100%;
  transition: all 0.3s;
  opacity: 0.5;
  pointer-events: none;
  text-transform: uppercase;
  letter-spacing: 1px;
}

.next-day-btn.active {
  background: var(--accent-green);
  color: #000;
  opacity: 1;
  pointer-events: all;
  box-shadow: 0 4px 20px rgba(0, 255, 136, 0.25);
}

.next-day-btn.active:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 24px rgba(0, 255, 136, 0.35);
}

/* Animations */
@keyframes slideIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

@keyframes pulse {
  0% { box-shadow: 0 0 0 0 rgba(0, 255, 136, 0.4); }
  70% { box-shadow: 0 0 0 10px rgba(0, 255, 136, 0); }
  100% { box-shadow: 0 0 0 0 rgba(0, 255, 136, 0); }
}

.success-pulse {
  animation: pulse 1.5s infinite;
}

/* Toast Notification */
.toast {
  position: absolute;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%) translateY(100px);
  background: var(--bg-color);
  border: 1px solid var(--accent-gold);
  color: var(--accent-gold);
  padding: 10px 20px;
  border-radius: 30px;
  font-size: 0.9rem;
  font-weight: 600;
  opacity: 0;
  transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
  box-shadow: 0 4px 12px rgba(0,0,0,0.5);
  z-index: 100;
  white-space: nowrap;
}

.toast.show {
  transform: translateX(-50%) translateY(0);
  opacity: 1;
}

/* Responsive */
@media (max-height: 700px) {
  .app-container {
    padding: 20px;
    gap: 16px;
  }
  .balance-display {
    font-size: 2rem;
  }
}