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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, Cantarell, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    padding: 20px;
    color: #333;
}

.container {
    max-width: 800px;
    margin: 0 auto;
}

header {
    text-align: center;
    color: white;
    margin-bottom: 30px;
}

.header-title {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 15px;
    margin-bottom: 10px;
}

.logo {
    width: 50px;
    height: 50px;
    object-fit: contain;
    filter: drop-shadow(2px 2px 4px rgba(0, 0, 0, 0.2));
}

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

.subtitle {
    font-size: 1.1rem;
    opacity: 0.9;
}

.card {
    background: white;
    border-radius: 12px;
    padding: 30px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    margin-bottom: 20px;
}

.section {
    margin-bottom: 30px;
    padding-bottom: 30px;
    border-bottom: 1px solid #e0e0e0;
}

.section:last-child {
    margin-bottom: 0;
    padding-bottom: 0;
    border-bottom: none;
}

.section h2 {
    color: #667eea;
    margin-bottom: 15px;
    font-size: 1.3rem;
}

/* Buttons */
.btn {
    padding: 12px 24px;
    font-size: 1rem;
    font-weight: 600;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    text-decoration: none;
}

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

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

.btn-primary:hover:not(:disabled) {
    background: #5568d3;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(102, 126, 234, 0.4);
}

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

.btn-secondary:hover:not(:disabled) {
    background: #5a6268;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(108, 117, 125, 0.4);
}

.btn-success {
    background: #28a745;
    color: white;
    font-size: 1.1rem;
    padding: 15px 30px;
}

.btn-success:hover:not(:disabled) {
    background: #218838;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(40, 167, 69, 0.4);
}

.btn-icon {
    font-size: 1.2rem;
}

/* Device Info */
.device-info {
    margin-top: 15px;
    padding: 15px;
    background: #e8f5e9;
    border-radius: 8px;
    display: flex;
    align-items: flex-start;
    gap: 12px;
    border: 2px solid #81c784;
    animation: slideIn 0.3s ease-out;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateY(-10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.device-details {
    flex: 1;
}

.device-details div {
    margin: 4px 0;
    color: #2e7d32;
    font-size: 0.95rem;
}

.device-details strong {
    color: #1b5e20;
}

.status-indicator {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    display: inline-block;
    margin-top: 4px;
    flex-shrink: 0;
}

.status-indicator.connected {
    background: #28a745;
    box-shadow: 0 0 8px rgba(40, 167, 69, 0.6);
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0%, 100% {
        box-shadow: 0 0 8px rgba(40, 167, 69, 0.6);
    }
    50% {
        box-shadow: 0 0 16px rgba(40, 167, 69, 0.8);
    }
}

.btn-connected {
    background: #28a745 !important;
    cursor: default !important;
}

/* File Input */
.file-input-wrapper {
    position: relative;
}

.file-input {
    position: absolute;
    opacity: 0;
    width: 0;
    height: 0;
}

.file-info {
    margin-top: 15px;
    padding: 12px;
    background: #e3f2fd;
    border-radius: 8px;
}

.file-info p {
    margin: 5px 0;
    color: #555;
}

/* Progress Bar */
.progress-container {
    margin-top: 20px;
}

.progress-info {
    display: flex;
    justify-content: space-between;
    margin-bottom: 8px;
    font-weight: 600;
    color: #667eea;
}

.progress-bar {
    width: 100%;
    height: 30px;
    background: #e0e0e0;
    border-radius: 15px;
    overflow: hidden;
    position: relative;
}

.progress-fill {
    height: 100%;
    background: linear-gradient(90deg, #667eea 0%, #764ba2 100%);
    width: 0%;
    transition: width 0.3s ease;
    border-radius: 15px;
    position: relative;
    overflow: hidden;
}

.progress-fill::after {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    bottom: 0;
    right: 0;
    background: linear-gradient(
        90deg,
        transparent,
        rgba(255, 255, 255, 0.3),
        transparent
    );
    animation: shimmer 2s infinite;
}

@keyframes shimmer {
    0% {
        transform: translateX(-100%);
    }
    100% {
        transform: translateX(100%);
    }
}

.status-message {
    margin-top: 12px;
    padding: 12px;
    border-radius: 6px;
    font-size: 0.9rem;
    white-space: pre-line;
    line-height: 1.6;
}

.status-message.success {
    background: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}

.status-message.error {
    background: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}

.status-message.info {
    background: #d1ecf1;
    color: #0c5460;
    border: 1px solid #bee5eb;
}

/* Info Box */
.info-box {
    background: white;
    border-radius: 12px;
    padding: 25px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.2);
    margin-bottom: 20px;
}

.info-box h3 {
    color: #667eea;
    margin-bottom: 15px;
}

.info-box ol {
    margin-left: 20px;
    line-height: 1.8;
}

.info-box li {
    margin: 8px 0;
}

.note {
    margin-top: 15px;
    padding: 12px;
    background: #fff3cd;
    border-left: 4px solid #ffc107;
    border-radius: 4px;
    font-size: 0.9rem;
}

/* Warning Box */
.warning-box {
    background: #fff3cd;
    border: 2px solid #ffc107;
    border-radius: 12px;
    padding: 20px;
    margin-bottom: 20px;
}

.warning-box strong {
    display: block;
    margin-bottom: 8px;
    color: #856404;
}

.warning-box p {
    color: #856404;
    margin: 0;
}

/* Footer */
footer {
    text-align: center;
    color: white;
    padding: 20px;
    opacity: 0.8;
}

/* Utility Classes */
.hidden {
    display: none !important;
}

/* Responsive */
@media (max-width: 600px) {
    header h1 {
        font-size: 2rem;
    }
    
    .logo {
        width: 40px;
        height: 40px;
    }
    
    .header-title {
        gap: 10px;
    }
    
    .card {
        padding: 20px;
    }
    
    .btn {
        width: 100%;
        justify-content: center;
    }
}