* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
}

.container {
    max-width: 1600px;
    margin: 0 auto;
    background: rgba(255, 255, 255, 0.95);
    border-radius: 20px;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
    overflow: hidden;
}

header {
    background: linear-gradient(135deg, #2c3e50 0%, #34495e 100%);
    color: white;
    padding: 30px;
    text-align: center;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 15px;
}

.subtitle {
    font-size: 1.1rem;
    opacity: 0.9;
}

.main-content {
    display: grid;
    grid-template-columns: 1fr 2fr;
    gap: 25px;
    padding: 25px;
}

@media (max-width: 1200px) {
    .main-content {
        grid-template-columns: 1fr;
    }
}

.card {
    background: white;
    border-radius: 15px;
    padding: 25px;
    margin-bottom: 25px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    border: 1px solid #e0e0e0;
}

.card h2 {
    color: #2c3e50;
    margin-bottom: 20px;
    font-size: 1.4rem;
    display: flex;
    align-items: center;
    gap: 10px;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    color: #555;
    font-weight: 500;
}

.form-group input,
.form-group select {
    width: 100%;
    padding: 12px 15px;
    border: 2px solid #ddd;
    border-radius: 10px;
    font-size: 1rem;
    transition: border-color 0.3s;
}

.form-group input:focus,
.form-group select:focus {
    outline: none;
    border-color: #667eea;
}

.btn {
    padding: 12px 25px;
    border: none;
    border-radius: 10px;
    font-size: 1rem;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    width: 100%;
    margin-bottom: 10px;
}

.btn-primary {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

.btn-success {
    background: linear-gradient(135deg, #10b981 0%, #059669 100%);
    color: white;
}

.btn-warning {
    background: linear-gradient(135deg, #f59e0b 0%, #d97706 100%);
    color: white;
}

.btn-danger {
    background: linear-gradient(135deg, #ef4444 0%, #dc2626 100%);
    color: white;
}

.btn-info {
    background: linear-gradient(135deg, #3b82f6 0%, #1d4ed8 100%);
    color: white;
}

.btn-secondary {
    background: linear-gradient(135deg, #6b7280 0%, #4b5563 100%);
    color: white;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 10px 20px rgba(0, 0, 0, 0.2);
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
}

.button-group {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 10px;
    margin-top: 20px;
}

.tabs {
    display: flex;
    gap: 5px;
    margin-bottom: 20px;
    background: #f8fafc;
    padding: 5px;
    border-radius: 10px;
}

.tab-btn {
    flex: 1;
    padding: 12px;
    border: none;
    background: none;
    cursor: pointer;
    border-radius: 8px;
    font-weight: 600;
    transition: all 0.3s;
}

.tab-btn.active {
    background: white;
    color: #667eea;
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.1);
}

.table-container {
    overflow-x: auto;
    border-radius: 10px;
    border: 1px solid #e5e7eb;
}

table {
    width: 100%;
    border-collapse: collapse;
    min-width: 600px;
}

thead {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
}

th {
    padding: 15px;
    text-align: left;
    font-weight: 600;
    font-size: 0.95rem;
}

tbody tr {
    border-bottom: 1px solid #e5e7eb;
    transition: background 0.3s;
}

tbody tr:hover {
    background: #f8fafc;
}

td {
    padding: 15px;
    color: #4b5563;
}

.status-badge {
    padding: 6px 12px;
    border-radius: 20px;
    font-size: 0.85rem;
    font-weight: 600;
    display: inline-block;
}

.status-requested { background: #fef3c7; color: #92400e; }
.status-allocated { background: #dbeafe; color: #1e40af; }
.status-occupied { background: #dcfce7; color: #166534; }
.status-released { background: #f3f4f6; color: #374151; }
.status-cancelled { background: #fee2e2; color: #991b1b; }

.availability {
    padding: 6px 12px;
    border-radius: 20px;
    font-weight: 600;
    font-size: 0.85rem;
}

.available { background: #d1fae5; color: #065f46; }
.occupied { background: #fee2e2; color: #991b1b; }

.stats-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
    margin-top: 15px;
}

.stat-card {
    background: #f8fafc;
    padding: 20px;
    border-radius: 12px;
    border: 1px solid #e5e7eb;
}

.stat-card h3 {
    font-size: 1rem;
    color: #6b7280;
    margin-bottom: 15px;
}

.stat-card div {
    font-size: 1.8rem;
    font-weight: bold;
    color: #2c3e50;
}

.zone-util {
    margin-bottom: 10px;
    padding-bottom: 10px;
    border-bottom: 1px solid #e5e7eb;
}

.zone-util:last-child {
    border-bottom: none;
}

.util-bar {
    height: 8px;
    background: #e5e7eb;
    border-radius: 4px;
    margin-top: 5px;
    overflow: hidden;
}

.util-fill {
    height: 100%;
    background: linear-gradient(90deg, #667eea, #764ba2);
    border-radius: 4px;
}

.rollback-stack {
    margin-top: 20px;
    padding-top: 20px;
    border-top: 1px solid #e5e7eb;
}

.rollback-stack h4 {
    margin-bottom: 15px;
    color: #4b5563;
}

#rollbackStack {
    background: #f8fafc;
    border-radius: 10px;
    padding: 15px;
    min-height: 150px;
    max-height: 200px;
    overflow-y: auto;
    border: 1px solid #e5e7eb;
}

.stack-item {
    background: white;
    padding: 10px;
    margin-bottom: 8px;
    border-radius: 8px;
    border-left: 4px solid #667eea;
    font-size: 0.9rem;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.05);
}

.notification-area {
    padding: 0 25px 25px;
}

#notification {
    padding: 15px 20px;
    border-radius: 10px;
    margin-bottom: 10px;
    font-weight: 500;
    display: none;
    animation: slideIn 0.3s ease;
}

@keyframes slideIn {
    from {
        transform: translateY(-20px);
        opacity: 0;
    }
    to {
        transform: translateY(0);
        opacity: 1;
    }
}

.notification-success {
    background: #d1fae5;
    color: #065f46;
    border: 1px solid #a7f3d0;
    display: block;
}

.notification-error {
    background: #fee2e2;
    color: #991b1b;
    border: 1px solid #fecaca;
    display: block;
}

.notification-warning {
    background: #fef3c7;
    color: #92400e;
    border: 1px solid #fde68a;
    display: block;
}

.cross-zone {
    color: #dc2626;
    font-weight: bold;
}

.util-high { color: #dc2626; }
.util-medium { color: #f59e0b; }
.util-low { color: #10b981; }