:root {
    --bg-color: #fafafa;
    --text-color: #111;
    --card-bg: #fff;
    --border-color: #eaeaea;
    --accent: #000;
    --accent-hover: #333;
    --danger: #e03131;
    --success: #0ca678;
    --info: #1c7ed6;
    --font-family: 'Inter', -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    --font-mono: ui-monospace, SFMono-Regular, Menlo, Monaco, Consolas, monospace;
}

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

body {
    font-family: var(--font-family);
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.5;
    display: flex;
    justify-content: center;
    padding: 2rem;
    min-height: 100vh;
    -webkit-font-smoothing: antialiased;
}

.dashboard {
    max-width: 540px;
    width: 100%;
    margin-top: 4vh;
}

header {
    text-align: center;
    margin-bottom: 2.5rem;
}

.brand-tag {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    background: #eee;
    color: #555;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    padding: 0.25rem 0.75rem;
    border-radius: 999px;
    margin-bottom: 1rem;
}

.pulse-dot {
    width: 6px;
    height: 6px;
    background-color: var(--danger);
    border-radius: 50%;
    animation: pulse 2s infinite;
}

@keyframes pulse {
    0% {
        transform: scale(0.95);
        opacity: 0.7;
    }

    50% {
        transform: scale(1.2);
        opacity: 1;
    }

    100% {
        transform: scale(0.95);
        opacity: 0.7;
    }
}

header h1 {
    font-size: 2.25rem;
    font-weight: 800;
    letter-spacing: -0.03em;
    line-height: 1.1;
}

.subtitle {
    color: #666;
    margin-top: 0.75rem;
    font-size: 1rem;
    font-weight: 400;
}

.card {
    background: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    padding: 2.5rem 2rem;
    box-shadow: 0 10px 40px rgba(0, 0, 0, 0.04);
    margin-bottom: 1.5rem;
}

/* Product Section */
.product-card {
    text-align: center;
}

.stock-display {
    margin-bottom: 2.5rem;
}

.stock-label {
    text-transform: uppercase;
    font-size: 0.75rem;
    letter-spacing: 0.15em;
    font-weight: 600;
    color: #888;
}

.stock-number {
    font-size: 5rem;
    font-weight: 800;
    line-height: 1;
    margin-top: 0.5rem;
    color: var(--accent);
    font-variant-numeric: tabular-nums;
    letter-spacing: -0.05em;
    transition: color 0.3s ease, transform 0.1s ease;
}

.stock-number.pop {
    transform: scale(1.05);
}

.stock-number.out-of-stock {
    color: var(--danger);
}

/* Tester Controls */
.controls-card {
    padding: 2rem;
}

.controls-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 1.25rem;
}

.controls-card h2 {
    font-size: 1.1rem;
    font-weight: 600;
    color: #333;
}

.status-badge {
    font-size: 0.75rem;
    font-weight: 600;
    padding: 0.25rem 0.5rem;
    border-radius: 6px;
    background: #f1f3f5;
    color: #495057;
}

.status-badge.online {
    background: #e6fcf5;
    color: #0ca678;
}

.status-badge.offline {
    background: #fff5f5;
    color: #e03131;
}

.test-config {
    display: flex;
    gap: 1rem;
    margin-bottom: 1.5rem;
}

.input-group {
    flex: 1;
}

.input-group label {
    display: block;
    font-size: 0.8rem;
    color: #555;
    margin-bottom: 0.5rem;
    font-weight: 500;
}

.input-group input {
    width: 100%;
    border: 1px solid #ddd;
    padding: 0.75rem;
    border-radius: 8px;
    font-family: var(--font-mono);
    font-size: 1rem;
    transition: border-color 0.2s;
}

.input-group input:focus {
    outline: none;
    border-color: var(--accent);
}

/* Base Buttons */
.btn {
    border: none;
    border-radius: 12px;
    padding: 1.125rem 2rem;
    font-size: 1.125rem;
    font-weight: 600;
    cursor: pointer;
    width: 100%;
    transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
    font-family: inherit;
}

.primary-btn {
    background-color: var(--accent);
    color: #fff;
    box-shadow: 0 4px 14px rgba(0, 0, 0, 0.1);
}

.primary-btn:hover:not(:disabled) {
    background-color: var(--accent-hover);
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.15);
}

.secondary-btn {
    background-color: transparent;
    color: var(--text-color);
    border: 1px solid #ccc;
    font-size: 1rem;
    padding: 0.875rem 1.5rem;
    margin-bottom: 1.5rem;
}

.secondary-btn:hover:not(:disabled) {
    background-color: #f8f9fa;
    border-color: #bbb;
}

.btn:active:not(:disabled) {
    transform: translateY(0);
}

.btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
    transform: none;
    box-shadow: none;
}

/* Log Console */
.log-console {
    background: #1a1b1e;
    color: #c1c2c5;
    font-family: var(--font-mono);
    font-size: 0.8rem;
    padding: 1rem;
    border-radius: 12px;
    height: 180px;
    overflow-y: auto;
    border: 1px solid var(--border-color);
}

.log-entry {
    margin-bottom: 6px;
    line-height: 1.4;
    word-break: break-all;
}

.log-error {
    color: #ff8787;
}

.log-success {
    color: #69db7c;
}

.log-info {
    color: #74c0fc;
}

.highlight {
    color: #868e96;
}

.log-console::-webkit-scrollbar {
    width: 6px;
}

.log-console::-webkit-scrollbar-track {
    background: #1a1b1e;
    border-radius: 4px;
}

.log-console::-webkit-scrollbar-thumb {
    background: #495057;
    border-radius: 4px;
}

.log-console::-webkit-scrollbar-thumb:hover {
    background: #5c5f66;
}

/* Explanation Panel */
.explanation-card {
    background: #f8f9fa;
    border: 1px solid var(--border-color);
    padding: 1.5rem;
    font-size: 0.95rem;
    color: #495057;
    animation: slideUp 0.3s ease;
}

.explanation-card.hidden {
    display: none;
}

.explanation-card h3 {
    margin-bottom: 0.5rem;
    color: #212529;
    font-size: 1.05rem;
}

.explanation-card p {
    line-height: 1.6;
}

.explanation-card strong {
    color: #212529;
}

@keyframes slideUp {
    from {
        opacity: 0;
        transform: translateY(10px);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}