:root {
    --primary-gradient: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    --success-color: #28a745;
    --info-color: #17a2b8;
    --warning-color: #ffc107;
}

body {
    background: linear-gradient(135deg, #1a1a2e 0%, #16213e 50%, #0f3460 100%);
    min-height: 100vh;
    color: #fff;
}

.speed-card {
    background: rgba(255, 255, 255, 0.1);
    backdrop-filter: blur(10px);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 20px;
    transition: transform 0.3s ease;
}

.speed-card:hover {
    transform: translateY(-5px);
}

.speed-value {
    font-size: 3rem;
    font-weight: bold;
    background: var(--primary-gradient);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.speed-unit {
    font-size: 1.2rem;
    color: #adb5bd;
}

.ping-value {
    font-size: 2rem;
    font-weight: bold;
}

.ping-idle { color: #28a745; }
.ping-download { color: #17a2b8; }
.ping-upload { color: #ffc107; }

.btn-start {
    background: var(--primary-gradient);
    border: none;
    padding: 15px 50px;
    font-size: 1.2rem;
    border-radius: 50px;
    transition: all 0.3s ease;
}

.btn-start:hover {
    transform: scale(1.05);
    box-shadow: 0 10px 30px rgba(102, 126, 234, 0.4);
}

.btn-stress {
    background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    border: none;
    padding: 15px 30px;
    font-size: 1.2rem;
    border-radius: 50px;
    transition: all 0.3s ease;
}

.btn-stress:hover {
    transform: scale(1.05);
    box-shadow: 0 10px 30px rgba(245, 87, 108, 0.4);
}

.btn-stop {
    background: linear-gradient(135deg, #ff416c 0%, #ff4b2b 100%);
    border: none;
    padding: 15px 50px;
    font-size: 1.2rem;
    border-radius: 50px;
}

.progress-container {
    height: 10px;
    background: rgba(255, 255, 255, 0.1);
    border-radius: 5px;
    overflow: hidden;
}

.progress-bar-animated {
    background: var(--primary-gradient);
    height: 100%;
    width: 0%;
    transition: width 0.3s ease;
}

.status-indicator {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    display: inline-block;
    margin-right: 8px;
}

.status-idle { background-color: #6c757d; }
.status-testing { background-color: #ffc107; animation: pulse 1s infinite; }
.status-complete { background-color: #28a745; }

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

.chart-container {
    background: rgba(255, 255, 255, 0.05);
    border-radius: 15px;
    padding: 20px;
    margin-top: 20px;
}

.unit-selector {
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 10px;
    padding: 5px;
}

.unit-selector .btn {
    color: #fff;
    border: none;
    padding: 8px 20px;
    border-radius: 8px;
}

.unit-selector .btn.active {
    background: var(--primary-gradient);
}

.unit-selector .btn:not(.active):hover {
    background: rgba(255, 255, 255, 0.1);
}

.size-selector {
    background: rgba(255, 255, 255, 0.1);
    border: 1px solid rgba(255, 255, 255, 0.2);
    border-radius: 10px;
    padding: 5px;
}

.size-selector .btn {
    color: #fff;
    border: none;
    padding: 8px 16px;
    border-radius: 8px;
    font-size: 0.9rem;
}

.size-selector .btn.active {
    background: linear-gradient(135deg, #11998e 0%, #38ef7d 100%);
}

.size-selector .btn:not(.active):hover {
    background: rgba(255, 255, 255, 0.1);
}

.ping-section {
    background: rgba(255, 255, 255, 0.05);
    border-radius: 15px;
    padding: 20px;
}

.stress-stats {
    background: rgba(245, 87, 108, 0.1);
    border: 1px solid rgba(245, 87, 108, 0.3);
    border-radius: 15px;
    padding: 20px;
}

/* 모바일 반응형 */
@media (max-width: 576px) {
    .speed-value {
        font-size: 2rem;
    }
    
    .ping-value {
        font-size: 1.5rem;
    }
    
    .btn-start, .btn-stress, .btn-stop {
        padding: 12px 24px;
        font-size: 1rem;
        width: 100%;
        margin-bottom: 10px;
    }
    
    .btn-start {
        margin-right: 0 !important;
    }
    
    .unit-selector, .size-selector {
        flex-wrap: wrap;
        justify-content: center;
    }
    
    .unit-selector .btn, .size-selector .btn {
        padding: 8px 12px;
        font-size: 0.85rem;
    }
    
    .size-selector {
        max-width: 100%;
    }
    
    .size-selector .btn {
        flex: 0 0 auto;
    }
    
    h1.display-4 {
        font-size: 1.8rem;
    }
    
    h1 i {
        display: none;
    }
}

@media (max-width: 768px) {
    .ping-section .row .col-md-4 {
        margin-bottom: 15px;
    }
}