body { font-family: 'Inter', sans-serif; }
        
        /* Custom Scrollbar for the main page */
        ::-webkit-scrollbar { width: 10px; }
        ::-webkit-scrollbar-track { background: #111827; }
        ::-webkit-scrollbar-thumb { background: #374151; border-radius: 5px; }
        ::-webkit-scrollbar-thumb:hover { background: #4b5563; }

        .tool-card {
            transition: all 0.2s ease-in-out;
        }
        .tool-card:hover {
            transform: translateY(-4px);
            box-shadow: 0 10px 15px -3px rgba(0, 0, 0, 0.3);
            border-color: #f59e0b; /* Amber border on hover */
        }
        
        .category-header {
            position: sticky;
            top: 0;
            z-index: 40;
            background-color: rgba(17, 24, 39, 0.95); /* Semi-transparent background */
            backdrop-filter: blur(5px);
        }

        #tuning-meter {
            position: relative;
            height: 24px;
            background-color: #1f2937;
            border-radius: 9999px;
            overflow: hidden;
            border: 2px solid #374151;
            box-shadow: inset 0 2px 4px rgba(0,0,0,0.3);
        }
        #tuning-needle {
            position: absolute;
            top: 0;
            left: 50%;
            width: 4px;
            height: 100%;
            background-color: #f59e0b;
            transform: translateX(-50%);
            border-radius: 2px;
            z-index: 10;
            will-change: left, background-color;
        }
        #center-line {
            position: absolute;
            left: 50%;
            top: 0;
            height: 100%;
            width: 4px;
            background-color: #4b5563;
            transform: translateX(-50%);
            z-index: 1;
        }
        
        /* Input Volume Meter */
        #volume-meter-container {
            width: 100%;
            height: 6px;
            background-color: #111827;
            border-radius: 999px;
            overflow: hidden;
            margin-top: 10px;
        }
        #volume-bar {
            height: 100%;
            width: 0%;
            background-color: #3b82f6; /* Blue */
            transition: width 0.05s linear;
        }
        
        .status-in-tune { color: #34d399; text-shadow: 0 0 10px rgba(52, 211, 153, 0.5); }
        .status-flat { color: #fbbf24; }
        .status-sharp { color: #fbbf24; }
        
        .string-btn { transition: all 0.2s ease-in-out; }
        .string-btn.active {
            background-color: #f59e0b;
            color: white;
            transform: scale(1.05);
            box-shadow: 0 0 15px rgba(245, 158, 11, 0.4);
        }

        .in-tune-glow {
             border-color: #34d399 !important;
             box-shadow: 0 0 30px rgba(52, 211, 153, 0.3), inset 0 0 20px rgba(52, 211, 153, 0.1);
             background-color: rgba(6, 78, 59, 0.3);
        }
        
        #tuner-display { transition: all 0.3s ease; }
        
        /* Slider Styling */
        input[type=range] {
            -webkit-appearance: none;
            width: 100%;
            background: transparent;
        }
        input[type=range]::-webkit-slider-thumb {
            -webkit-appearance: none;
            height: 20px;
            width: 20px;
            border-radius: 50%;
            background: #f59e0b;
            margin-top: -8px;
            cursor: pointer;
        }
        input[type=range]::-webkit-slider-runnable-track {
            width: 100%;
            height: 4px;
            cursor: pointer;
            background: #4b5563;
            border-radius: 2px;
        }
        
        .mt-8 {
            margin-top: 1rem!important;
        }
        .min-h-screen {
            min-height: 90vh!important;
            max-height: 92vh!important;
        }