:root {
    --primary-color: #333;
    --secondary-color: #666;
    --background-color: #f5f5f5;
    --card-background: #fff;
    --border-color: #e0e0e0;
    --text-primary: #1a1a1a;
    --text-secondary: #666;
    --hover-bg: #fafafa;
    --shadow: 0 2px 8px rgba(0,0,0,0.08);
    --sidebar-width: 280px;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: var(--background-color);
    color: var(--text-primary);
    line-height: 1.6;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 40px 20px;
}

.card {
    background: var(--card-background);
    border-radius: 12px;
    box-shadow: var(--shadow);
    padding: 30px;
    margin-bottom: 24px;
    border: 1px solid var(--border-color);
    transition: box-shadow 0.3s;
}

.card:hover {
    box-shadow: 0 4px 16px rgba(0,0,0,0.12);
}

.card-title {
    font-size: 20px;
    font-weight: 600;
    color: var(--text-primary);
    margin-bottom: 24px;
    padding-bottom: 16px;
    border-bottom: 1px solid var(--border-color);
}

.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 24px;
}

.form-group {
    margin-bottom: 24px;
}

.form-group label {
    display: block;
    margin-bottom: 10px;
    font-weight: 500;
    color: var(--text-primary);
    font-size: 14px;
}

.form-group input[type="text"],
.form-group input[type="email"],
.form-group input[type="password"],
.form-group input[type="number"],
.form-group textarea,
.form-group select {
    width: 100%;
    padding: 14px 16px;
    border: 1px solid var(--border-color);
    border-radius: 8px;
    font-size: 14px;
    transition: all 0.3s;
    background: #fff;
}

.form-group input:hover,
.form-group textarea:hover,
.form-group select:hover {
    border-color: var(--secondary-color);
}

.form-group input:focus,
.form-group textarea:focus,
.form-group select:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(51,51,51,0.1);
}

.form-group textarea {
    resize: vertical;
    min-height: 120px;
}

.form-group .hint {
    font-size: 12px;
    color: var(--text-secondary);
    margin-top: 6px;
}

.btn {
    padding: 14px 28px;
    border: none;
    border-radius: 8px;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
}

.btn-primary {
    background: var(--primary-color);
    color: #fff;
}

.btn-primary:hover {
    background: #1a1a1a;
    transform: translateY(-1px);
}

.btn-secondary {
    background: var(--secondary-color);
    color: #fff;
}

.btn-secondary:hover {
    background: #555;
}

.btn-danger {
    background: #dc3545;
    color: #fff;
}

.btn-danger:hover {
    background: #c82333;
}

.btn-success {
    background: #28a745;
    color: #fff;
}

.btn-success:hover {
    background: #218838;
}

.btn-outline {
    background: transparent;
    border: 1px solid var(--border-color);
    color: var(--text-primary);
}

.btn-outline:hover {
    background: var(--hover-bg);
    border-color: var(--primary-color);
}

.btn-sm {
    padding: 10px 18px;
    font-size: 13px;
}

.btn-lg {
    padding: 16px 32px;
    font-size: 16px;
}

.table-container {
    overflow-x: auto;
}

.table {
    width: 100%;
    border-collapse: collapse;
    background: #fff;
}

.table th,
.table td {
    padding: 16px;
    text-align: left;
    border-bottom: 1px solid var(--border-color);
}

.table th {
    background: var(--hover-bg);
    font-weight: 600;
    color: var(--text-primary);
    font-size: 13px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.table tr:hover {
    background: var(--hover-bg);
}

.table td {
    font-size: 14px;
}

.badge {
    display: inline-block;
    padding: 6px 12px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 500;
}

.badge-pending {
    background: #fff3cd;
    color: #856404;
}

.badge-approved {
    background: #d4edda;
    color: #155724;
}

.badge-rejected {
    background: #f8d7da;
    color: #721c24;
}

.badge-available {
    background: #d4edda;
    color: #155724;
}

.badge-used {
    background: #f8d7da;
    color: #721c24;
}

.badge-exchanged {
    background: #cce5ff;
    color: #004085;
}

.text-center { text-align: center; }
.text-right { text-align: right; }
.mt-20 { margin-top: 20px; }
.mt-30 { margin-top: 30px; }
.mb-20 { margin-bottom: 20px; }
.mb-30 { margin-bottom: 30px; }

.alert {
    padding: 16px 20px;
    border-radius: 8px;
    margin-bottom: 24px;
    font-size: 14px;
}

.alert-success {
    background: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}

.alert-error {
    background: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}

.alert-info {
    background: #d1ecf1;
    color: #0c5460;
    border: 1px solid #bee5eb;
}

.alert-warning {
    background: #fff3cd;
    color: #856404;
    border: 1px solid #ffeaa7;
}

.page-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 32px;
}

.page-title {
    font-size: 28px;
    font-weight: 700;
    color: var(--text-primary);
}

.page-subtitle {
    font-size: 14px;
    color: var(--text-secondary);
    margin-top: 4px;
}

.grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 24px;
}

.stat-card {
    background: var(--card-background);
    border-radius: 12px;
    padding: 28px;
    box-shadow: var(--shadow);
    border: 1px solid var(--border-color);
}

.stat-card .stat-value {
    font-size: 36px;
    font-weight: 700;
    color: var(--text-primary);
}

.stat-card .stat-label {
    font-size: 14px;
    color: var(--text-secondary);
    margin-top: 8px;
}

.stat-card .stat-icon {
    font-size: 32px;
    margin-bottom: 12px;
}

img {
    max-width: 100%;
    height: auto;
}

img.thumbnail {
    max-width: 120px;
    border-radius: 6px;
    cursor: pointer;
    border: 1px solid var(--border-color);
    transition: transform 0.3s;
}

img.thumbnail:hover {
    transform: scale(1.05);
}

.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.5);
    z-index: 1000;
    align-items: center;
    justify-content: center;
}

.modal.active {
    display: flex;
}

.modal-content {
    background: #fff;
    border-radius: 12px;
    padding: 32px;
    max-width: 700px;
    width: 90%;
    max-height: 85vh;
    overflow-y: auto;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
    padding-bottom: 16px;
    border-bottom: 1px solid var(--border-color);
}

.modal-title {
    font-size: 20px;
    font-weight: 600;
}

.modal-close {
    background: none;
    border: none;
    font-size: 28px;
    cursor: pointer;
    color: var(--text-secondary);
    line-height: 1;
}

.modal-close:hover {
    color: var(--text-primary);
}

.form-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 20px;
}

.actions {
    display: flex;
    gap: 10px;
}

.empty-state {
    text-align: center;
    padding: 60px 20px;
    color: var(--text-secondary);
}

.empty-state svg {
    font-size: 64px;
    margin-bottom: 20px;
    opacity: 0.5;
}

.empty-state h3 {
    font-size: 18px;
    margin-bottom: 8px;
    color: var(--text-primary);
}

.empty-state p {
    font-size: 14px;
}

.file-upload {
    border: 2px dashed var(--border-color);
    border-radius: 8px;
    padding: 40px 20px;
    text-align: center;
    cursor: pointer;
    transition: all 0.3s;
}

.file-upload:hover {
    border-color: var(--primary-color);
    background: var(--hover-bg);
}

.file-upload input {
    display: none;
}

.file-upload .icon {
    font-size: 48px;
    color: var(--text-secondary);
    margin-bottom: 12px;
}

.file-upload .text {
    font-size: 14px;
    color: var(--text-secondary);
}

.image-preview {
    margin-top: 16px;
    position: relative;
    display: inline-block;
}

.image-preview img {
    max-width: 200px;
    border-radius: 8px;
    border: 1px solid var(--border-color);
}

.image-preview .remove {
    position: absolute;
    top: -10px;
    right: -10px;
    width: 24px;
    height: 24px;
    background: #dc3545;
    color: #fff;
    border-radius: 50%;
    border: none;
    cursor: pointer;
    font-size: 14px;
    line-height: 24px;
}

@media (max-width: 768px) {
    .container {
        padding: 20px 15px;
    }
    
    .card {
        padding: 20px;
    }
    
    .page-header {
        flex-direction: column;
        align-items: flex-start;
        gap: 12px;
    }
    
    .table {
        font-size: 12px;
    }
    
    .table th,
    .table td {
        padding: 10px 8px;
    }
    
    .card-grid {
        grid-template-columns: 1fr;
    }
    
    .actions {
        flex-direction: column;
    }
}