.form-range {
    width: 100%;
  }
  #frequencyValue {
    font-size: 24px;
    font-weight: bold;
  }
  .result {
    font-size: 24px;
    font-weight: bold;
    color: #007bff;
  }
  .btn-play {
    width: 100%;
    margin-top: 10px;
  }
  .freq-control {
    display: flex;
    align-items: center;
    justify-content: center;
    margin-top: 15px;
  }
  .freq-btn {
    width: 40px;
    height: 40px;
    font-size: 18px;
    display: flex;
    align-items: center;
    justify-content: center;
    padding-top: 10px;
  }
  .warning-icon {
    color: #dc3545;
    width: 50px;
    height: 50px;    
  }
  .instruction-step {
    margin-bottom: 15px;
    padding-left: 10px;
    border-left: 3px solid #007bff;
  }


.oscilloscope-container {
    width: 100%;
    aspect-ratio: 2 / 1;
    background: #444b53;
    /* border: 1px solid rgba(75, 85, 99, 0.3); */
    /* border-radius: 4px; */
    overflow: hidden;
    margin-bottom: 12px;
}

#oscilloscope {
    width: 100%;
    height: 100%;
    display: block;
}

.frequency-display {
    text-align: center;
    margin-bottom: 24px;
}

#frequencyValue {
    font-size: 48px;
    font-weight: 300;
    color: #f3f4f6;
    display: block;
    margin-bottom: 4px;
}

.unit {
    font-size: 20px;
    font-weight: 300;
    color: #dc3545;
}

.slider-container {
    margin-bottom: 24px;
}

.slider {
    width: 100%;
    height: 6px;
    border-radius: 3px;
    background: #374151;
    outline: none;
    -webkit-appearance: none;
    appearance: none;
    cursor: pointer;
}

.slider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: #dc3545;
    cursor: pointer;
    transition: all 0.2s;
}

.slider::-webkit-slider-thumb:hover {
    background: #c82333;
    transform: scale(1.2);
}

.slider::-moz-range-thumb {
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: #dc3545;
    cursor: pointer;
    border: none;
    transition: all 0.2s;
}

.slider::-moz-range-thumb:hover {
    background: #c82333;
    transform: scale(1.2);
}

.controls {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 16px;
    margin-bottom: 24px;
}

.btn {
    border: none;
    border-radius: 50%;
    cursor: pointer;
    font-size: 16px;
    font-weight: 500;
    transition: all 0.3s;
    display: flex;
    align-items: center;
    justify-content: center;
}

.btn-small {
    width: 48px;
    height: 48px;
    background: #374151;
    color: #dc3545;
    font-size: 24px;
}

.btn-small:hover {
    background: #4b5563;
}

.loop-btn {
    width: 48px;
    height: 48px;
    background: #374151;
    color: #9ca3af;
    border-radius: 50%;
    position: absolute;
    left: 50%;
    margin-left: -105px;
}

.loop-btn.active {
    background: #dc3545;
    color: white;
}

.btn-small:active {
    transform: scale(0.95);
}

.btn-play {    
    width: 80px;
    height: 80px;
    background: #dc3545;
    color: white;
    font-size: 40px;
    box-shadow: 0 10px 30px rgba(220, 53, 69, 0.3);
}

.btn-play:hover {
    background: #c82333;
}

.btn-play:active {
    transform: scale(0.98);
}

.btn-play.playing {
    background: #c82333;
}

.mode-controls {
    display: grid;
    grid-template-columns: 1fr 1fr 1fr;
    gap: 12px;
    margin-top: 24px;
}

.mode-btn {
    padding: 10px 16px;
    background: #374151;
    border: 2px solid transparent;
    border-radius: 8px;
    color: #9ca3af;
    font-size: 14px;
    font-weight: 500;
    cursor: pointer;
    transition: all 0.3s;
}

.mode-btn:hover {
    background: #4b5563;
    color: #f3f4f6;
}

.mode-btn.active {
    background: #dc3545;
    color: white;
    border-color: #dc3545;
}

.sweep-param {
    margin-bottom: 20px;
}

.sweep-param label {
    display: block;
    font-size: 13px;
    color: #9ca3af;
    margin-bottom: 8px;
    font-weight: 500;
}

.param-input {
    display: flex;
    align-items: center;
    gap: 8px;
}

.param-field {
    flex: 1;
    padding: 10px 12px;
    background: #374151;
    border: 1px solid #4b5563;
    border-radius: 6px;
    color: #f3f4f6;
    font-size: 14px;
    font-weight: 500;
}

.param-field:focus {
    outline: none;
    border-color: #dc3545;
    background: #4b5563;
}

.param-unit {
    font-size: 12px;
    color: #dc3545;
    font-weight: 500;
    min-width: 25px;
}

@media (max-width: 480px) {
    .mode-btn {
        font-size: 11px;
    }

    #frequencyValue {
        font-size: 30px;
        margin-bottom: 0;
    }

    .unit {
        font-size: 15px;
    }

    .btn-play {
        width: 70px;
        height: 70px;
        font-size: 30px;
    }

    .btn-small {
        width: 40px;
        height: 40px;
        font-size: 20px;
    }

    .title {
        font-size: 20px;
    }
}