:root {
            --bg-dark: #0f172a;
            --bg-panel: #1e293b;
            --text-primary: #f8fafc;
            --text-secondary: #94a3b8;
            --accent-cyan: #06b6d4;
            --accent-blue: #3b82f6;
            --accent-purple: #8b5cf6;
            --success: #10b981;
            --gauge-track: #334155;
        }

* { box-sizing: border-box; }

body {
            font-family: 'Inter', sans-serif;
            margin: 0;
            padding: 0;
            background-color: var(--bg-dark);
            color: var(--text-primary);
            min-height: 100vh;
            display: flex;
            align-items: center;
            justify-content: center;
            overflow-x: hidden;
             /* Deep radial gradient to match the logo background */
    background-image: url('assets/animated-bg2.svg');
    background-size: cover;
    background-attachment: fixed;
    padding-bottom: 80px;
        }

        /* --- Main Container --- */
        .app-container {
            width: 100%;
            max-width: 480px;
            background: var(--bg-panel);
            border-radius: 24px;
            padding: 40px 24px;
            box-shadow: 0 20px 50px rgba(0,0,0,0.5);
            display: flex;
            flex-direction: column;
            align-items: center;
            position: relative;
            overflow: hidden;
        }

        /* Ambient Glow Background */
        .app-container::before {
            content: '';
            position: absolute;
            top: -50%;
            left: -50%;
            width: 200%;
            height: 200%;
            background: radial-gradient(circle, rgba(6,182,212,0.08) 0%, rgba(15,23,42,0) 70%);
            z-index: 0;
            pointer-events: none;
        }

        .content-wrapper {
            position: relative;
            z-index: 10;
            width: 100%;
            display: flex;
            flex-direction: column;
            align-items: center;
        }

        /* --- Header Indicators (Ping, DL, UL) --- */
        .indicators-row {
            display: flex;
            justify-content: space-between;
            width: 100%;
            margin-bottom: 30px;
            padding: 0 10px;
        }

        .indicator {
            display: flex;
            flex-direction: column;
            align-items: center;
            opacity: 0.4;
            transition: all 0.3s ease;
        }

        .indicator.active {
            opacity: 1;
            transform: translateY(-2px);
        }

        .indicator-icon {
            font-size: 1.2rem;
            margin-bottom: 4px;
            color: var(--accent-cyan);
        }

        .indicator-label {
            font-size: 0.75rem;
            text-transform: uppercase;
            letter-spacing: 1px;
            color: var(--text-secondary);
        }

        .indicator-value {
            font-family: 'JetBrains Mono', monospace;
            font-size: 1rem;
            font-weight: 700;
            margin-top: 2px;
            min-height: 1.5rem;
        }

        /* --- The Gauge (SVG) --- */
        .gauge-wrapper {
            position: relative;
            width: 280px;
            height: 280px;
            margin: 10px 0 20px 0;
        }

        svg.gauge-svg {
            width: 100%;
            height: 100%;
            transform: rotate(135deg); /* Start from bottom-left */
        }

        .gauge-track {
            fill: none;
            stroke: var(--gauge-track);
            stroke-width: 12;
            stroke-linecap: round;
        }

        .gauge-fill {
            fill: none;
            stroke: url(#gradientSpeed);
            stroke-width: 12;
            stroke-linecap: round;
            stroke-dasharray: 0, 1000; /* Controlled by JS */
            transition: stroke-dasharray 0.1s linear;
            filter: drop-shadow(0 0 8px rgba(6,182,212,0.5));
        }

        /* Center Text inside Gauge */
        .gauge-center {
            position: absolute;
            top: 50%;
            left: 50%;
            transform: translate(-50%, -50%);
            text-align: center;
            width: 100%;
        }

        .main-speed-value {
            font-family: 'Inter', sans-serif;
            font-size: 3.5rem;
            font-weight: 800;
            color: #fff;
            letter-spacing: -2px;
            line-height: 1;
            text-shadow: 0 0 20px rgba(6,182,212,0.3);
        }

        .main-speed-unit {
            font-size: 1rem;
            color: var(--text-secondary);
            margin-top: 8px;
            font-weight: 400;
        }

        /* --- Status & User Info --- */
        .status-display {
            font-size: 0.9rem;
            color: var(--accent-cyan);
            margin-bottom: 24px;
            height: 20px;
            font-weight: 600;
            letter-spacing: 0.5px;
            text-transform: uppercase;
        }

        /* --- Action Button --- */
        .start-btn {
            background: linear-gradient(135deg, var(--accent-cyan), var(--accent-blue));
            border: none;
            border-radius: 50px;
            padding: 16px 48px;
            font-size: 1.1rem;
            font-weight: 700;
            color: white;
            cursor: pointer;
            box-shadow: 0 10px 20px -5px rgba(6,182,212,0.4);
            transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
            position: relative;
            overflow: hidden;
            width: 100%;
            max-width: 220px;
        }

        .start-btn:hover:not(:disabled) {
            transform: translateY(-2px) scale(1.02);
            box-shadow: 0 15px 30px -5px rgba(6,182,212,0.6);
        }

        .start-btn:active:not(:disabled) {
            transform: translateY(1px) scale(0.98);
        }

        .start-btn:disabled {
            background: var(--gauge-track);
            color: var(--text-secondary);
            cursor: not-allowed;
            box-shadow: none;
        }

        /* Cool ripple effect on button */
        .start-btn::after {
            content: "";
            position: absolute;
            top: 0; left: 0; right: 0; bottom: 0;
            background: rgba(255,255,255,0.1);
            opacity: 0;
            transition: opacity 0.3s;
        }
        .start-btn:hover::after { opacity: 1; }

        /* --- Loader Animation --- */
        .loader-ring {
            display: inline-block;
            width: 20px;
            height: 20px;
            border: 3px solid rgba(255,255,255,0.3);
            border-radius: 50%;
            border-top-color: #fff;
            animation: spin 1s ease-in-out infinite;
            margin-left: 10px;
            vertical-align: middle;
            display: none; /* hidden by default */
        }
        .loader-ring.active { display: inline-block; }

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

        /*Footer section*/

.footer {
    background-color: #121212;
    color: #aaa;
    text-align: center;
    padding: 15px 10px;
    font-size: 0.9rem;
    margin-top: 0;
    position: fixed;
    left: 0;
    bottom: 0;
    width: 100%;
    z-index: 1000;
}

.footer a {
  color: #17a5df;
  text-decoration: none;
  margin: 0 8px;
}

.footer a:hover {
  text-decoration: underline;
}