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

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: linear-gradient(135deg, #0ab024 0%, #0c8920 100%);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    padding: 20px;
    gap: 20px;
}

.logo {
    max-width: 300px;
    width: 100%;
    height: auto;
    display: block;
}

.container {
    background: white;
    border-radius: 20px;
    padding: 40px;
    max-width: 600px;
    width: 100%;
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.3);
}

h1 {
    text-align: center;
    color: #333;
    margin-bottom: 30px;
    font-size: 2.5em;
}

h2 {
    color: #555;
    margin-bottom: 20px;
    font-size: 1.5em;
}

/* Toggle de modo oscuro */
.dark-mode-toggle-container {
    text-align: center;
    padding-bottom: 20px;
    margin-bottom: 20px;
    border-bottom: 2px solid #eee;
}

/* Menú de ejercicios */
.menu {
    margin-bottom: 30px;
    padding-bottom: 30px;
    border-bottom: 2px solid #eee;
}

.button-group {
    display: flex;
    gap: 15px;
    justify-content: center;
}

.menu-btn {
    flex: 1;
    padding: 15px 25px;
    font-size: 1.1em;
    font-weight: 600;
    border: 2px solid #0ab024;
    background: white;
    color: #0ab024;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.menu-btn:hover {
    background: #f0f0f0;
}

.menu-btn.active {
    background: #0ab024;
    color: #f6d20b;
}

/* Ejercicios */
.ejercicio {
    display: none;
    animation: fadeIn 0.5s ease;
}

.ejercicio.active {
    display: block;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* Display box */
.display-box {
    background: linear-gradient(135deg, #0ab024 0%, #0c8920 100%);
    border-radius: 15px;
    padding: 40px;
    margin-bottom: 30px;
    text-align: center;
}

/* Nota al Azar */
.nota-display {
    color: #f6d20b;
}

.nota-display .nota {
    display: block;
    font-size: 4em;
    font-weight: bold;
    margin-bottom: 10px;
}

.nota-display .cuerda {
    display: block;
    font-size: 2em;
    font-weight: bold;
    color: #f6d20b;
}

/* Metrónomo */
.bpm-display {
    color: #f6d20b;
    margin-bottom: 20px;
}

#bpmValue {
    display: block;
    font-size: 4em;
    font-weight: bold;
}

.bpm-label {
    display: block;
    font-size: 1.2em;
    opacity: 0.9;
}

.beat-indicator {
    width: 80px;
    height: 80px;
    background: rgba(246, 210, 11, 0.3);
    border-radius: 50%;
    margin: 20px auto 0;
    transition: all 0.05s ease;
}

.beat-indicator.beat {
    background: #f6d20b;
    transform: scale(1.1);
}

/* Control de tempo */
.tempo-control {
    margin-bottom: 30px;
}

.tempo-control label {
    display: block;
    margin-bottom: 10px;
    color: #555;
    font-weight: 600;
}

#tempoSlider {
    width: 100%;
    height: 8px;
    border-radius: 5px;
    background: #ddd;
    outline: none;
    -webkit-appearance: none;
}

#tempoSlider::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 25px;
    height: 25px;
    border-radius: 50%;
    background: #0ab024;
    cursor: pointer;
}

#tempoSlider::-moz-range-thumb {
    width: 25px;
    height: 25px;
    border-radius: 50%;
    background: #0ab024;
    cursor: pointer;
    border: none;
}

.tempo-marks {
    display: flex;
    justify-content: space-between;
    margin-top: 5px;
    color: #999;
    font-size: 0.9em;
}

.bpm-input-group {
    margin-top: 20px;
}

.bpm-input-group label {
    display: block;
    margin-bottom: 8px;
    color: #555;
    font-weight: 600;
    font-size: 0.95em;
}

#bpmInput,
#bpmInputCombinado {
    width: 100%;
    padding: 12px;
    font-size: 1.1em;
    border: 2px solid #ddd;
    border-radius: 8px;
    text-align: center;
    font-weight: 600;
    color: #0ab024;
    transition: border-color 0.3s ease;
}

#bpmInput:focus,
#bpmInputCombinado:focus {
    outline: none;
    border-color: #0ab024;
}

/* Ejercicio combinado */
.ejercicio-description {
    text-align: center;
    color: #666;
    margin-bottom: 20px;
    font-style: italic;
}

.bpm-display-small {
    color: #f6d20b;
    margin-top: 15px;
    opacity: 0.9;
}

#bpmValueCombinado {
    font-size: 1.5em;
    font-weight: bold;
    margin-right: 5px;
}

.bpm-label-small {
    font-size: 1em;
}

/* Botones de acción */
.action-btn {
    width: 100%;
    padding: 18px;
    font-size: 1.2em;
    font-weight: 600;
    background: #0ab024;
    color: white;
    border: none;
    border-radius: 10px;
    cursor: pointer;
    transition: all 0.3s ease;
}

.action-btn:hover {
    background: #0c8920;
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(10, 176, 36, 0.4);
}

.action-btn:active {
    transform: translateY(0);
}

/* Toggle de alteraciones */
.toggle-container {
    margin-bottom: 20px;
    display: flex;
    justify-content: center;
    gap: 20px;
    flex-wrap: wrap;
}

.toggle-label {
    display: inline-flex;
    align-items: center;
    cursor: pointer;
    gap: 12px;
    user-select: none;
}

.toggle-label input[type="checkbox"] {
    display: none;
}

.toggle-slider {
    position: relative;
    width: 50px;
    height: 26px;
    background: #ccc;
    border-radius: 13px;
    transition: background 0.3s ease;
}

.toggle-slider::before {
    content: '';
    position: absolute;
    width: 20px;
    height: 20px;
    border-radius: 50%;
    background: white;
    top: 3px;
    left: 3px;
    transition: transform 0.3s ease;
}

.toggle-label input[type="checkbox"]:checked + .toggle-slider {
    background: #0ab024;
}

.toggle-label input[type="checkbox"]:checked + .toggle-slider::before {
    transform: translateX(24px);
}

.toggle-text {
    color: #555;
    font-weight: 500;
    font-size: 0.95em;
}

/* Modo Oscuro */
body.dark-mode {
    background: linear-gradient(135deg, #1b263a 0%, #273853 100%);
}

body.dark-mode .container {
    background: #294163;
    color: #e8edf6;
}

body.dark-mode h2 {
    color: #ccd8eb;
}

body.dark-mode .menu-btn {
    border-color: #4a76ad;
    background: #2e4a76;
    color: #ccd8eb;
}

body.dark-mode .menu-btn:hover {
    background: #385d91;
}

body.dark-mode .menu-btn.active {
    background: #4a76ad;
    color: #f6d20b;
}

body.dark-mode .display-box {
    background: linear-gradient(135deg, #2e4a76 0%, #385d91 100%);
}

body.dark-mode .action-btn {
    background: #4a76ad;
}

body.dark-mode .action-btn:hover {
    background: #6c93c4;
    box-shadow: 0 5px 15px rgba(74, 118, 173, 0.4);
}

body.dark-mode #tempoSlider,
body.dark-mode #tempoSliderCombinado {
    background: #385d91;
}

body.dark-mode #tempoSlider::-webkit-slider-thumb,
body.dark-mode #tempoSliderCombinado::-webkit-slider-thumb {
    background: #6c93c4;
}

body.dark-mode #tempoSlider::-moz-range-thumb,
body.dark-mode #tempoSliderCombinado::-moz-range-thumb {
    background: #6c93c4;
}

body.dark-mode .tempo-control label {
    color: #ccd8eb;
}

body.dark-mode .tempo-marks {
    color: #a0b9d9;
}

body.dark-mode .bpm-input-group label {
    color: #ccd8eb;
}

body.dark-mode #bpmInput,
body.dark-mode #bpmInputCombinado {
    background: #2e4a76;
    border-color: #385d91;
    color: #6c93c4;
}

body.dark-mode #bpmInput:focus,
body.dark-mode #bpmInputCombinado:focus {
    border-color: #6c93c4;
}

body.dark-mode .ejercicio-description {
    color: #a0b9d9;
}

body.dark-mode .toggle-text {
    color: #ccd8eb;
}

body.dark-mode .toggle-slider {
    background: #385d91;
}

body.dark-mode .toggle-label input[type="checkbox"]:checked + .toggle-slider {
    background: #4a76ad;
}

body.dark-mode .menu {
    border-bottom-color: #385d91;
}

body.dark-mode .dark-mode-toggle-container {
    border-bottom-color: #385d91;
}

/* Responsive */
@media (max-width: 600px) {
    .container {
        padding: 25px;
    }

    h1 {
        font-size: 2em;
    }

    .nota-display .nota,
    #bpmValue {
        font-size: 3em;
    }

    .button-group {
        flex-direction: column;
    }
}