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

:root {
    --primary-color: #4a90e2;
    --success-color: #52c41a;
    --warning-color: #faad14;
    --error-color: #f5222d;
    --bg-primary: #f0f2f5;
    --bg-secondary: #ffffff;
    --text-primary: #262626;
    --text-secondary: #8c8c8c;
    --border-color: #d9d9d9;
    --shadow: 0 2px 8px rgba(0,0,0,0.1);
    --shadow-hover: 0 4px 12px rgba(0,0,0,0.15);
}

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;
    color: var(--text-primary);
}

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

header {
    text-align: center;
    color: white;
    margin-bottom: 30px;
    animation: fadeInDown 0.6s ease;
}

header h1 {
    font-size: 2.5rem;
    margin-bottom: 10px;
    text-shadow: 2px 2px 4px rgba(0,0,0,0.2);
}

header p {
    font-size: 1.1rem;
    opacity: 0.95;
}

.main-card {
    background: var(--bg-secondary);
    border-radius: 12px;
    padding: 30px;
    box-shadow: var(--shadow);
    animation: fadeInUp 0.6s ease;
}

.input-section {
    display: grid;
    grid-template-columns: 1fr auto;
    gap: 15px;
    margin-bottom: 25px;
}

.input-group {
    position: relative;
}

.input-group input {
    width: 100%;
    padding: 12px 15px 12px 45px;
    border: 2px solid var(--border-color);
    border-radius: 8px;
    font-size: 16px;
    transition: all 0.3s ease;
}

.input-group input:focus {
    outline: none;
    border-color: var(--primary-color);
    box-shadow: 0 0 0 3px rgba(74, 144, 226, 0.1);
}

.input-group .icon {
    position: absolute;
    left: 15px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-secondary);
}

.btn {
    padding: 12px 30px;
    border: none;
    border-radius: 8px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 8px;
}

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

.btn-primary:hover {
    background: #3a7bc8;
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
}

.btn-primary:disabled {
    background: #bfbfbf;
    cursor: not-allowed;
    transform: none;
}

.btn-secondary {
    background: #f0f0f0;
    color: var(--text-primary);
}

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

.settings-section {
    background: var(--bg-primary);
    border-radius: 8px;
    padding: 20px;
    margin-bottom: 25px;
}

.settings-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
}

.setting-item {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.setting-item label {
    font-size: 14px;
    color: var(--text-secondary);
    font-weight: 500;
}

.setting-item input,
.setting-item select {
    padding: 8px 12px;
    border: 1px solid var(--border-color);
    border-radius: 6px;
    font-size: 14px;
    transition: all 0.3s ease;
}

.setting-item input:focus,
.setting-item select:focus {
    outline: none;
    border-color: var(--primary-color);
}

.tabs {
    display: flex;
    gap: 10px;
    margin-bottom: 20px;
    border-bottom: 2px solid var(--border-color);
}

.tab {
    padding: 10px 20px;
    background: none;
    border: none;
    font-size: 15px;
    color: var(--text-secondary);
    cursor: pointer;
    position: relative;
    transition: all 0.3s ease;
}

.tab.active {
    color: var(--primary-color);
}

.tab.active::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    right: 0;
    height: 2px;
    background: var(--primary-color);
}

.tab-content {
    display: none;
    animation: fadeIn 0.3s ease;
}

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

.results-section {
    background: var(--bg-primary);
    border-radius: 8px;
    padding: 20px;
    min-height: 300px;
}

.ping-result {
    display: flex;
    align-items: center;
    padding: 12px;
    background: white;
    border-radius: 6px;
    margin-bottom: 10px;
    border-left: 4px solid var(--success-color);
    animation: slideIn 0.3s ease;
}

.ping-result.error {
    border-left-color: var(--error-color);
}

.ping-result.warning {
    border-left-color: var(--warning-color);
}

.ping-sequence {
    font-weight: 600;
    margin-right: 15px;
    color: var(--text-secondary);
}

.ping-time {
    flex: 1;
    font-size: 16px;
}

.ping-status {
    display: flex;
    align-items: center;
    gap: 8px;
}

.status-indicator {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--success-color);
    animation: pulse 2s infinite;
}

.status-indicator.error {
    background: var(--error-color);
    animation: none;
}

.status-indicator.warning {
    background: var(--warning-color);
    animation: none;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
    gap: 15px;
    margin-top: 20px;
}

.stat-card {
    background: white;
    padding: 15px;
    border-radius: 8px;
    text-align: center;
    transition: transform 0.3s ease;
}

.stat-card:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow);
}

.stat-value {
    font-size: 24px;
    font-weight: 700;
    color: var(--primary-color);
    margin-bottom: 5px;
}

.stat-label {
    font-size: 12px;
    color: var(--text-secondary);
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

.chart-container {
    background: white;
    padding: 20px;
    border-radius: 8px;
    margin-top: 20px;
    height: 300px;
    position: relative;
}

.chart {
    width: 100%;
    height: 100%;
}

.empty-state {
    text-align: center;
    padding: 40px;
    color: var(--text-secondary);
}

.empty-state svg {
    width: 80px;
    height: 80px;
    margin-bottom: 15px;
    opacity: 0.3;
}

.loading {
    display: inline-block;
    width: 20px;
    height: 20px;
    border: 3px solid rgba(255,255,255,0.3);
    border-radius: 50%;
    border-top-color: white;
    animation: spin 1s ease-in-out infinite;
}

.progress-bar {
    width: 100%;
    height: 4px;
    background: var(--border-color);
    border-radius: 2px;
    overflow: hidden;
    margin-top: 10px;
}

.progress-fill {
    height: 100%;
    background: var(--primary-color);
    transition: width 0.3s ease;
}

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

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

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

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

@keyframes pulse {
    0% { opacity: 1; }
    50% { opacity: 0.5; }
    100% { opacity: 1; }
}

@keyframes spin {
    to { transform: rotate(360deg); }
}

@media (max-width: 768px) {
    header h1 {
        font-size: 2rem;
    }

    .input-section {
        grid-template-columns: 1fr;
    }

    .settings-grid {
        grid-template-columns: 1fr;
    }

    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}