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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f8f9fa;
    color: #333;
    line-height: 1.6;
}

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

/* Header */
.header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 1rem 0;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
}

.user-info {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.user-name {
    font-weight: 500;
}

.logout-btn {
    background: rgba(255,255,255,0.2);
    color: white;
    border: none;
    padding: 0.5rem 1rem;
    border-radius: 5px;
    cursor: pointer;
    text-decoration: none;
    transition: background-color 0.3s;
}

.logout-btn:hover {
    background: rgba(255,255,255,0.3);
}

/* Navigation */
.nav {
    background: white;
    padding: 0;
    border-bottom: 1px solid #e9ecef;
}

.nav-tabs {
    display: flex;
    list-style: none;
    margin: 0;
    padding: 0;
}

.nav-tab {
    margin: 0;
}

.nav-link {
    display: block;
    padding: 1rem 1.5rem;
    color: #6c757d;
    text-decoration: none;
    border-bottom: 3px solid transparent;
    transition: all 0.3s;
}

.nav-link:hover,
.nav-link.active {
    color: #667eea;
    border-bottom-color: #667eea;
    background-color: #f8f9fa;
}

/* Main Content */
.main-content {
    padding: 2rem 0;
    min-height: calc(100vh - 120px);
}

/* Cards */
.card {
    background: white;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    margin-bottom: 1.5rem;
    overflow: hidden;
}

.card-header {
    background-color: #f8f9fa;
    padding: 1rem 1.5rem;
    border-bottom: 1px solid #e9ecef;
    font-weight: 600;
    color: #495057;
}

.card-body {
    padding: 1.5rem;
}

/* Forms */
.form-group {
    margin-bottom: 1rem;
}

.form-label {
    display: block;
    margin-bottom: 0.5rem;
    font-weight: 500;
    color: #495057;
}

.form-control {
    width: 100%;
    padding: 0.75rem;
    border: 1px solid #ced4da;
    border-radius: 5px;
    font-size: 1rem;
    transition: border-color 0.3s, box-shadow 0.3s;
}

.form-control:focus {
    outline: none;
    border-color: #667eea;
    box-shadow: 0 0 0 0.2rem rgba(102, 126, 234, 0.25);
}

.form-control.is-invalid {
    border-color: #dc3545;
}

.invalid-feedback {
    display: block;
    color: #dc3545;
    font-size: 0.875rem;
    margin-top: 0.25rem;
}

/* Buttons */
.btn {
    display: inline-block;
    padding: 0.75rem 1.5rem;
    font-size: 1rem;
    font-weight: 500;
    text-align: center;
    text-decoration: none;
    border: none;
    border-radius: 5px;
    cursor: pointer;
    transition: all 0.3s;
    margin-right: 0.5rem;
}

.btn-primary {
    background-color: #667eea;
    color: white;
}

.btn-primary:hover {
    background-color: #5a6fd8;
    transform: translateY(-1px);
}

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

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

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

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

.btn-info {
    background-color: #17a2b8;
    color: white;
}

.btn-info:hover {
    background-color: #138496;
}

.btn-secondary {
    background-color: #6c757d;
    color: white;
}

.btn-secondary:hover {
    background-color: #5a6268;
}

.btn-sm {
    padding: 0.5rem 1rem;
    font-size: 0.875rem;
}

/* Tables */
.table {
    width: 100%;
    border-collapse: collapse;
    background: white;
}

.table th,
.table td {
    padding: 0.75rem;
    text-align: left;
    border-bottom: 1px solid #e9ecef;
}

.table th {
    background-color: #f8f9fa;
    font-weight: 600;
    color: #495057;
}

.table tbody tr:hover {
    background-color: #f8f9fa;
}

/* Status badges */
.badge {
    display: inline-block;
    padding: 0.25rem 0.5rem;
    font-size: 0.75rem;
    font-weight: 500;
    border-radius: 3px;
    text-transform: uppercase;
}

.badge-pending {
    background-color: #ffc107;
    color: #212529;
}

.badge-sent {
    background-color: #28a745;
    color: white;
}

.badge-rejected {
    background-color: #dc3545;
    color: white;
}

.badge-archived {
    background-color: #6c757d;
    color: white;
}

/* Alerts */
.alert {
    padding: 0.75rem 1rem;
    margin-bottom: 1rem;
    border: 1px solid transparent;
    border-radius: 5px;
}

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

.alert-danger {
    color: #721c24;
    background-color: #f8d7da;
    border-color: #f5c6cb;
}

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

/* Modal */
.modal {
    display: none;
    position: fixed;
    z-index: 1000;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0,0,0,0.5);
}

.modal.show {
    display: flex;
    align-items: center;
    justify-content: center;
}

.modal-content {
    background-color: white;
    border-radius: 8px;
    max-width: 800px;
    width: 90%;
    max-height: 90%;
    overflow-y: auto;
}

.modal-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 1.5rem;
    border-bottom: 1px solid #e9ecef;
}

.modal-title {
    font-size: 1.25rem;
    font-weight: 600;
    margin: 0;
}

.modal-close {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: #6c757d;
}

.modal-close:hover {
    color: #495057;
}

.modal-body {
    padding: 1.5rem;
}

.modal-footer {
    display: flex;
    justify-content: flex-end;
    gap: 0.5rem;
    padding: 1rem 1.5rem;
    border-top: 1px solid #e9ecef;
}

/* Statistics */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: white;
    padding: 1.5rem;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    text-align: center;
}

.stat-number {
    font-size: 2rem;
    font-weight: bold;
    color: #667eea;
    margin-bottom: 0.5rem;
}

.stat-label {
    color: #6c757d;
    font-size: 0.875rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

/* Login page */
.login-container {
    display: flex;
    align-items: center;
    justify-content: center;
    min-height: 100vh;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
}

.login-card {
    background: white;
    padding: 2rem;
    border-radius: 10px;
    box-shadow: 0 10px 25px rgba(0,0,0,0.2);
    width: 100%;
    max-width: 400px;
}

.login-header {
    text-align: center;
    margin-bottom: 2rem;
}

.login-title {
    font-size: 1.5rem;
    color: #333;
    margin-bottom: 0.5rem;
}

.login-subtitle {
    color: #6c757d;
    font-size: 0.875rem;
}

/* Responsive */
@media (max-width: 768px) {
    .header-content {
        flex-direction: column;
        gap: 1rem;
    }
    
    .nav-tabs {
        flex-wrap: wrap;
    }
    
    .table-responsive {
        overflow-x: auto;
    }
    
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .modal-content {
        width: 95%;
        margin: 1rem;
    }
}

/* Loading spinner */
.spinner {
    border: 3px solid #f3f3f3;
    border-top: 3px solid #667eea;
    border-radius: 50%;
    width: 30px;
    height: 30px;
    animation: spin 1s linear infinite;
    margin: 1rem auto;
}

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