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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
}

.header {
    background: white;
    border-radius: 15px 15px 0 0;
    padding: 30px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

h1 {
    color: #667eea;
    font-size: 28px;
    margin-bottom: 8px;
}

.subtitle {
    color: #666;
    font-size: 15px;
}

.nav-links {
    margin-top: 15px;
    display: flex;
    gap: 15px;
    flex-wrap: wrap;
}

.nav-link {
    display: inline-block;
    padding: 8px 16px;
    background: #f0f0f0;
    color: #667eea;
    text-decoration: none;
    border-radius: 6px;
    font-size: 14px;
    transition: all 0.2s;
}

.nav-link:hover {
    background: #667eea;
    color: white;
}

.filters {
    background: white;
    padding: 20px 30px;
    display: flex;
    gap: 15px;
    flex-wrap: wrap;
    align-items: center;
    border-top: 1px solid #e0e0e0;
}

.filter-tabs {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

.filter-tab {
    padding: 10px 20px;
    border: 2px solid #e0e0e0;
    background: white;
    color: #666;
    border-radius: 8px;
    cursor: pointer;
    font-size: 14px;
    font-weight: 600;
    transition: all 0.2s;
}

.filter-tab:hover {
    border-color: #667eea;
    color: #667eea;
}

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

.search-box {
    flex: 1;
    min-width: 250px;
}

.search-box input {
    width: 100%;
    padding: 10px 15px;
    border: 2px solid #e0e0e0;
    border-radius: 8px;
    font-size: 14px;
}

.search-box input:focus {
    outline: none;
    border-color: #667eea;
}

.content {
    background: white;
    border-radius: 0 0 15px 15px;
    padding: 30px;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.2);
}

.stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 15px;
    margin-bottom: 25px;
}

.stat-card {
    padding: 20px;
    background: linear-gradient(135deg, #f5f7fa 0%, #c3cfe2 100%);
    border-radius: 10px;
    text-align: center;
}

.stat-number {
    font-size: 32px;
    font-weight: bold;
    color: #667eea;
}

.stat-label {
    font-size: 14px;
    color: #666;
    margin-top: 5px;
}

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

table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 20px;
}

th {
    background: #f8f9fa;
    padding: 15px;
    text-align: left;
    font-weight: 600;
    color: #333;
    font-size: 14px;
    border-bottom: 2px solid #e0e0e0;
}

td {
    padding: 15px;
    border-bottom: 1px solid #f0f0f0;
    font-size: 14px;
}

tr:hover {
    background: #f8f9fa;
}

.status-badge {
    display: inline-block;
    padding: 5px 12px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
    text-transform: uppercase;
}

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

.status-sent {
    background: #d1ecf1;
    color: #0c5460;
}

.status-opened {
    background: #d4edda;
    color: #155724;
}

.btn {
    padding: 8px 16px;
    border: none;
    border-radius: 6px;
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.2s;
}

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

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.3);
}

.btn-secondary {
    background: #f0f0f0;
    color: #666;
}

.btn-secondary:hover {
    background: #e0e0e0;
}

.tracking-id {
    font-family: 'Courier New', monospace;
    font-size: 12px;
    color: #667eea;
    background: #f0f0f0;
    padding: 3px 8px;
    border-radius: 4px;
}

.loading {
    text-align: center;
    padding: 40px;
    color: #666;
}

.spinner {
    border: 3px solid #f3f3f3;
    border-top: 3px solid #667eea;
    border-radius: 50%;
    width: 40px;
    height: 40px;
    animation: spin 1s linear infinite;
    margin: 0 auto 15px;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.empty-state {
    text-align: center;
    padding: 60px 20px;
    color: #999;
}

.empty-state-icon {
    font-size: 64px;
    margin-bottom: 15px;
}

.alert {
    padding: 15px 20px;
    border-radius: 8px;
    margin-bottom: 20px;
    font-size: 14px;
}

.alert-info {
    background: #d1ecf1;
    border-left: 4px solid #0c5460;
    color: #0c5460;
}

.alert-success {
    background: #d4edda;
    border-left: 4px solid #155724;
    color: #155724;
}

.alert-warning {
    background: #fff3cd;
    border-left: 4px solid #856404;
    color: #856404;
}

@media (max-width: 768px) {
    .header { padding: 20px; }
    h1 { font-size: 22px; }
    .filters { padding: 15px 20px; }
    .content { padding: 20px; }
    table { font-size: 12px; }
    th, td { padding: 10px; }
    .tracking-id { font-size: 10px; }
}

/* Global Navigation */
.global-nav {
    display: flex;
    justify-content: center;
    gap: 15px;
    background: rgba(255, 255, 255, 0.95);
    padding: 15px;
    box-shadow: 0 4px 15px rgba(0, 0, 0, 0.1);
    position: sticky;
    top: 0;
    z-index: 1000;
    backdrop-filter: blur(10px);
}
.global-nav .nav-btn {
    text-decoration: none;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 10px 20px;
    border-radius: 25px;
    font-weight: 600;
    font-size: 15px;
    transition: transform 0.2s, box-shadow 0.2s;
    display: inline-flex;
    align-items: center;
    gap: 8px;
}
.global-nav .nav-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(102, 126, 234, 0.4);
}