:root {
    --primary: #2563eb;
    --primary-hover: #1d4ed8;
    --secondary: #64748b;
    --secondary-hover: #475569;
    --success: #22c55e;
    --warning: #f59e0b;
    --error: #ef4444;
    --bg: #f8fafc;
    --bg-card: #ffffff;
    --border: #e2e8f0;
    --text: #1e293b;
    --text-muted: #64748b;
    --shadow: 0 1px 3px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1);
    --radius: 8px;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.5;
}

.header {
    background: var(--bg-card);
    border-bottom: 1px solid var(--border);
    padding: 1rem 2rem;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: var(--shadow);
}

.header h1 {
    font-size: 1.5rem;
    font-weight: 600;
}

.header-right {
    display: flex;
    align-items: center;
    gap: 1rem;
}

#user-info {
    color: var(--text-muted);
    font-size: 0.875rem;
}

.btn {
    padding: 0.5rem 1rem;
    border: none;
    border-radius: var(--radius);
    font-size: 0.875rem;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.2s;
}

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

.btn-primary:hover {
    background: var(--primary-hover);
}

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

.btn-secondary:hover {
    background: var(--secondary-hover);
}

.btn-danger {
    background: var(--error);
    color: white;
}

.btn-success {
    background: var(--success);
    color: white;
}

.btn-large {
    padding: 0.75rem 2rem;
    font-size: 1rem;
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

.login-screen {
    min-height: calc(100vh - 60px);
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 2rem;
}

.login-card {
    background: var(--bg-card);
    padding: 3rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
    text-align: center;
    max-width: 400px;
    width: 100%;
}

.login-card h2 {
    margin-bottom: 0.5rem;
}

.login-card p {
    color: var(--text-muted);
    margin-bottom: 2rem;
}

.config-section {
    margin-top: 2rem;
    text-align: left;
}

.config-section details {
    background: var(--bg);
    padding: 1rem;
    border-radius: var(--radius);
}

.config-section summary {
    cursor: pointer;
    font-weight: 500;
    margin-bottom: 1rem;
}

.error-message {
    color: var(--error);
    margin-top: 1rem;
    font-size: 0.875rem;
}

.main-app {
    padding: 2rem;
    max-width: 1400px;
    margin: 0 auto;
}

.tabs {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 2rem;
    border-bottom: 2px solid var(--border);
    padding-bottom: 0.5rem;
}

.tab {
    padding: 0.75rem 1.5rem;
    background: transparent;
    border: none;
    border-radius: var(--radius) var(--radius) 0 0;
    cursor: pointer;
    font-size: 0.875rem;
    font-weight: 500;
    color: var(--text-muted);
    transition: all 0.2s;
}

.tab:hover {
    color: var(--text);
    background: var(--bg);
}

.tab.active {
    color: var(--primary);
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-bottom-color: var(--bg-card);
    margin-bottom: -3px;
}

.tab-content {
    display: none;
}

.tab-content.active {
    display: block;
}

.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.5rem;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 1rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: var(--bg-card);
    padding: 1.5rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    text-align: center;
}

.stat-card h3 {
    font-size: 0.75rem;
    text-transform: uppercase;
    color: var(--text-muted);
    margin-bottom: 0.5rem;
}

.stat-value {
    font-size: 2rem;
    font-weight: 700;
}

.stat-value.success { color: var(--success); }
.stat-value.warning { color: var(--warning); }
.stat-value.error { color: var(--error); }

.data-table {
    width: 100%;
    background: var(--bg-card);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    border-collapse: collapse;
    overflow: hidden;
}

.data-table th,
.data-table td {
    padding: 0.75rem 1rem;
    text-align: left;
    border-bottom: 1px solid var(--border);
}

.data-table th {
    background: var(--bg);
    font-weight: 600;
    font-size: 0.75rem;
    text-transform: uppercase;
    color: var(--text-muted);
}

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

.data-table tbody tr:last-child td {
    border-bottom: none;
}

.status-badge {
    display: inline-block;
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
}

.status-received { background: #dbeafe; color: #1e40af; }
.status-sending { background: #fef3c7; color: #92400e; }
.status-sent { background: #dcfce7; color: #166534; }
.status-failed { background: #fee2e2; color: #991b1b; }
.status-dead { background: #fecaca; color: #7f1d1d; }
.status-spam { background: #f3e8ff; color: #6b21a8; }

.filters {
    display: flex;
    gap: 1rem;
    margin-bottom: 1.5rem;
    flex-wrap: wrap;
}

.filters select,
.filters input {
    padding: 0.5rem 1rem;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-size: 0.875rem;
}

.pagination {
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 1rem;
    margin-top: 1.5rem;
}

.loading {
    text-align: center;
    padding: 3rem;
    color: var(--text-muted);
}

.modal {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0, 0, 0, 0.5);
    z-index: 1000;
    align-items: center;
    justify-content: center;
    padding: 1rem;
}

.modal.active {
    display: flex;
}

.modal-content {
    background: var(--bg-card);
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
    max-width: 500px;
    width: 100%;
    max-height: 90vh;
    overflow-y: auto;
}

.modal-large {
    max-width: 800px;
}

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

.modal-header h2 {
    font-size: 1.25rem;
}

.modal-close {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-muted);
}

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

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

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

.form-group label {
    display: block;
    font-size: 0.875rem;
    font-weight: 500;
    margin-bottom: 0.25rem;
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 0.5rem;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    font-size: 0.875rem;
}

.form-group textarea {
    resize: vertical;
    font-family: inherit;
}

.form-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
}

.form-section {
    padding: 1.5rem;
    border-bottom: 1px solid var(--border);
}

.form-section h3 {
    font-size: 1rem;
    margin-bottom: 1rem;
    color: var(--text-muted);
}

.tester-form {
    background: var(--bg-card);
    padding: 2rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    max-width: 600px;
}

.tester-result {
    margin-top: 1.5rem;
    padding: 1rem;
    border-radius: var(--radius);
}

.tester-result.success {
    background: #dcfce7;
    color: #166534;
}

.tester-result.error {
    background: #fee2e2;
    color: #991b1b;
}

#submission-detail {
    padding: 1.5rem;
}

#submission-detail h3 {
    margin-top: 1.5rem;
    margin-bottom: 0.75rem;
    font-size: 1rem;
    color: var(--text-muted);
}

#submission-detail h3:first-child {
    margin-top: 0;
}

.detail-grid {
    display: grid;
    grid-template-columns: 140px 1fr;
    gap: 0.5rem 1rem;
}

.detail-grid dt {
    font-weight: 500;
    color: var(--text-muted);
}

.detail-message {
    background: var(--bg);
    padding: 1rem;
    border-radius: var(--radius);
    white-space: pre-wrap;
    font-family: inherit;
}

.attempts-list {
    list-style: none;
}

.attempts-list li {
    padding: 0.75rem;
    border: 1px solid var(--border);
    border-radius: var(--radius);
    margin-bottom: 0.5rem;
    font-size: 0.875rem;
}

.attempts-list li.success {
    background: #dcfce7;
}

.attempts-list li.failed {
    background: #fee2e2;
}

.form-key-display {
    font-family: monospace;
    font-size: 0.8rem;
    background: var(--bg);
    padding: 0.25rem 0.5rem;
    border-radius: 4px;
    word-break: break-all;
}

.action-buttons {
    display: flex;
    gap: 0.25rem;
}

.action-buttons .btn {
    padding: 0.25rem 0.5rem;
    font-size: 0.75rem;
}

@media (max-width: 768px) {
    .header {
        padding: 1rem;
    }
    
    .main-app {
        padding: 1rem;
    }
    
    .tabs {
        flex-wrap: wrap;
    }
    
    .filters {
        flex-direction: column;
    }
    
    .data-table {
        display: block;
        overflow-x: auto;
    }
}