:root {
  /* Color Palette - Premium Dark */
  --bg-color: #0c0c0e;
  --surface-color: #1a1a1d;
  --surface-hover: #252529;
  --primary-color: #8b5cf6;
  --primary-hover: #a78bfa;
  --accent-color: #06b6d4;
  --success-color: #10b981;
  --danger-color: #ef4444;
  --warning-color: #f59e0b;
  --border-color: #2d2d33;
  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  
  /* Layout */
  --sidebar-width: 380px;
  --header-height: 64px;
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 18px;
  --shadow-sm: 0 1px 2px 0 rgb(0 0 0 / 0.05);
  --shadow-md: 0 4px 6px -1px rgb(0 0 0 / 0.1);
  --shadow-lg: 0 10px 15px -3px rgb(0 0 0 / 0.1);
  
  /* Transitions */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  -webkit-tap-highlight-color: transparent;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  background-color: var(--bg-color);
  color: var(--text-primary);
  line-height: 1.5;
  overflow: hidden;
  height: 100vh;
}

.hidden { display: none !important; }

#app {
  display: grid;
  grid-template-columns: 1fr var(--sidebar-width);
  grid-template-rows: var(--header-height) 1fr;
  height: 100vh;
}

header {
  grid-column: 1 / -1;
  background-color: var(--surface-color);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 24px;
  z-index: 10;
}

.logo {
  font-size: 1.25rem;
  font-weight: 800;
  letter-spacing: -0.025em;
  background: linear-gradient(135deg, var(--primary-color), var(--accent-color));
  background-clip: text;
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
}

main {
  padding: 24px;
  overflow-y: auto;
  background-color: var(--bg-color);
}

aside {
  background-color: var(--surface-color);
  border-left: 1px solid var(--border-color);
  display: flex;
  flex-direction: column;
  height: 100%;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 10px 20px;
  border-radius: var(--radius-md);
  font-weight: 600;
  cursor: pointer;
  transition: var(--transition-normal);
  border: none;
  gap: 8px;
}

.btn-primary { background-color: var(--primary-color); color: white; }
.btn-ghost { background: transparent; color: var(--text-secondary); }

/* Navigation */
.nav-links { display: flex; gap: 8px; height: 100%; }
.nav-btn { background: transparent; border: none; color: var(--text-secondary); display: flex; flex-direction: column; align-items: center; justify-content: center; padding: 0 16px; cursor: pointer; border-bottom: 2px solid transparent; font-family: inherit; transition: all 0.2s; }
.nav-btn i { stroke: var(--text-secondary); transition: stroke 0.2s; }
.nav-btn:hover { color: var(--text-primary); }
.nav-btn.active { color: var(--primary-color); border-bottom-color: var(--primary-color); background: rgba(139, 92, 246, 0.05); }
.nav-btn.active i { stroke: var(--primary-color); }

/* Product Grid */
.product-grid { display: grid; grid-template-columns: repeat(auto-fill, minmax(160px, 1fr)); gap: 16px; margin-top: 24px; }
.product-card { background: var(--surface-color); border: 1px solid var(--border-color); border-radius: var(--radius-lg); padding: 16px; cursor: pointer; transition: var(--transition-normal); position: relative; }
.product-card:hover { border-color: var(--primary-color); transform: translateY(-4px); }
.product-card .price { font-size: 1.1rem; font-weight: 800; color: var(--primary-color); margin-top: 8px; }
.product-card .name { font-weight: 600; font-size: 0.95rem; margin-top: 4px; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }

/* Cart */
.cart-header { padding: 24px; border-bottom: 1px solid var(--border-color); display: flex; justify-content: space-between; align-items: center; }
.cart-items-list { flex: 1; overflow-y: auto; padding: 16px; }
.cart-item { display: flex; justify-content: space-between; margin-bottom: 12px; background: rgba(255,255,255,0.02); padding: 12px; border-radius: var(--radius-md); border: 1px solid var(--border-color); }
.cart-footer { padding: 24px; background: var(--surface-color); border-top: 1px solid var(--border-color); }
.summary-line { display: flex; justify-content: space-between; font-size: 0.9rem; color: var(--text-secondary); margin-bottom: 4px; }
.total-line { display: flex; justify-content: space-between; font-size: 1.5rem; font-weight: 800; margin-top: 12px; }

/* Modal */
.modal-overlay { position: fixed; inset: 0; background: rgba(0,0,0,0.8); backdrop-filter: blur(4px); display: flex; align-items: center; justify-content: center; z-index: 100; }
.modal-content { background: var(--surface-color); width: 90%; max-width: 500px; border-radius: var(--radius-lg); padding: 24px; border: 1px solid var(--border-color); }

/* Inventory Table */
.inventory-table-container { margin-top: 24px; overflow: auto; background: var(--surface-color); border-radius: var(--radius-md); }
table { width: 100%; border-collapse: collapse; }
th, td { padding: 12px; text-align: left; border-bottom: 1px solid var(--border-color); }
th { color: var(--text-secondary); font-size: 0.8rem; text-transform: uppercase; }

input { background: var(--bg-color); border: 1px solid var(--border-color); color: var(--text-primary); padding: 8px 12px; border-radius: var(--radius-sm); width: 100%; transition: var(--transition-fast); }
input:focus { border-color: var(--primary-color); outline: none; }

/* Cash Management Modal */
.cash-management h2 { margin-bottom: 24px; text-align: center; font-family: 'Outfit', sans-serif; }
.denomination-grid { display: flex; flex-direction: column; gap: 8px; max-height: 400px; overflow-y: auto; padding-right: 8px; }
.denom-row { display: grid; grid-template-columns: 100px 1fr 100px; align-items: center; gap: 16px; padding: 12px; background: rgba(255,255,255,0.02); border-radius: var(--radius-md); border: 1px solid var(--border-color); }
.denom-label { font-weight: 700; color: var(--text-secondary); }
.denom-input-group { display: flex; align-items: center; gap: 8px; }
.denom-input { text-align: right; font-weight: 600; font-size: 1.1rem; }
.denom-unit { color: var(--text-muted); font-size: 0.8rem; }
.denom-subtotal { text-align: right; color: var(--primary-color); font-weight: 700; }
.cash-summary { margin-top: 24px; padding: 24px; background: rgba(139, 92, 246, 0.1); border-radius: var(--radius-md); border: 1px solid var(--primary-color); display: flex; justify-content: space-between; align-items: center; font-size: 1.25rem; font-weight: 800; }

.modal-actions { display: grid; grid-template-columns: 1fr 1fr; gap: 12px; margin-top: 24px; }

.badge { display: inline-flex; align-items: center; gap: 8px; padding: 6px 12px; border-radius: 999px; border: 1px solid var(--border-color); font-size: 0.8rem; font-weight: 700; cursor: pointer; transition: var(--transition-normal); }
.badge:hover { transform: scale(1.05); }

.tm { font-size: 0.5em; vertical-align: super; margin-left: 2px; }

.logo-container { display: flex; align-items: center; gap: 12px; }
.header-icon { width: 32px; height: 32px; border-radius: 6px; object-fit: cover; border: 1px solid rgba(255,255,255,0.1); }

.legal-links { display: flex; flex-direction: column; gap: 8px; margin-bottom: 24px; }
.full-width { width: 100%; justify-content: flex-start; background: rgba(255,255,255,0.03); border: 1px solid var(--border-color); }
.full-width:hover { background: var(--surface-hover); border-color: var(--text-muted); }

.about-app { text-align: center; color: var(--text-muted); font-size: 0.8rem; border-top: 1px solid var(--border-color); padding-top: 24px; margin-top: 24px; }
.about-app p { margin-bottom: 4px; }

.legal-content-area { line-height: 1.8; color: var(--text-secondary); font-size: 0.9rem; max-height: 60vh; overflow-y: auto; padding-right: 12px; }
.legal-content-area h3 { color: var(--text-primary); margin: 20px 0 10px 0; font-size: 1rem; }
.legal-content-area ul { padding-left: 20px; margin-bottom: 16px; }
.legal-content-area li { margin-bottom: 8px; }