.tutorial-link {
    display: inline-block;
    margin-top: 15px;
    color: var(--primary-color);
    font-weight: 500;
    border-bottom: 1px solid transparent;
}

.tutorial-link:hover {
    border-bottom-color: var(--primary-color);
}

.sleep-app {
    max-width: 800px;
    margin: 0 auto;
}

.master-control {
    background-color: var(--white);
    border-radius: 16px;
    padding: 25px;
    box-shadow: var(--shadow);
    margin-bottom: 25px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 30px;
}

.master-btn {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 15px 30px;
    background: linear-gradient(135deg, var(--primary-color), #3D7A8C);
    color: var(--white);
    border-radius: 12px;
    font-weight: 600;
    font-size: 1.1rem;
    transition: var(--transition);
}

.master-btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-hover);
}

.master-btn.playing {
    background: linear-gradient(135deg, #E53E3E, #C53030);
}

.master-btn svg {
    width: 24px;
    height: 24px;
}

.master-volume {
    flex: 1;
    max-width: 300px;
}

.master-volume label {
    display: block;
    font-size: 0.9rem;
    color: #64748B;
    margin-bottom: 10px;
}

.master-volume input {
    width: 100%;
    height: 8px;
    -webkit-appearance: none;
    background: var(--border-color);
    border-radius: 4px;
    outline: none;
}

.master-volume input::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 20px;
    height: 20px;
    background: var(--primary-color);
    border-radius: 50%;
    cursor: pointer;
}

.sounds-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
    margin-bottom: 25px;
}

.sound-card {
    background-color: var(--white);
    border-radius: 16px;
    padding: 25px;
    box-shadow: var(--shadow);
    text-align: center;
    transition: var(--transition);
}

.sound-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-hover);
}

.sound-card.active {
    border: 2px solid var(--primary-color);
}

.sound-icon {
    width: 60px;
    height: 60px;
    margin: 0 auto 15px;
    background-color: var(--accent-color);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
}

.sound-icon svg {
    width: 28px;
    height: 28px;
    color: var(--primary-color);
}

.sound-card h3 {
    font-size: 1rem;
    color: var(--text-color);
    margin-bottom: 15px;
}

.sound-controls {
    display: flex;
    align-items: center;
    gap: 15px;
}

.sound-toggle {
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background-color: var(--bg-color);
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
    flex-shrink: 0;
}

.sound-toggle:hover {
    background-color: var(--primary-color);
    color: var(--white);
}

.sound-toggle svg {
    width: 18px;
    height: 18px;
}

.sound-card.active .sound-toggle {
    background-color: var(--primary-color);
    color: var(--white);
}

.sound-volume {
    flex: 1;
    height: 6px;
    -webkit-appearance: none;
    background: var(--border-color);
    border-radius: 3px;
    outline: none;
}

.sound-volume::-webkit-slider-thumb {
    -webkit-appearance: none;
    width: 16px;
    height: 16px;
    background: var(--primary-color);
    border-radius: 50%;
    cursor: pointer;
}

.timer-section {
    background-color: var(--white);
    border-radius: 16px;
    padding: 25px;
    box-shadow: var(--shadow);
    text-align: center;
}

.timer-section h3 {
    font-size: 1.1rem;
    color: var(--text-color);
    margin-bottom: 20px;
}

.timer-options {
    display: flex;
    justify-content: center;
    gap: 10px;
    margin-bottom: 20px;
}

.timer-btn {
    padding: 10px 20px;
    background-color: var(--bg-color);
    border-radius: 8px;
    font-weight: 500;
    color: var(--text-color);
    transition: var(--transition);
}

.timer-btn:hover {
    background-color: var(--accent-color);
}

.timer-btn.active {
    background-color: var(--primary-color);
    color: var(--white);
}

.timer-display {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 5px;
}

.timer-remaining {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-color);
}

.timer-label {
    font-size: 0.9rem;
    color: #64748B;
}

@media (max-width: 768px) {
    .master-control {
        flex-direction: column;
        gap: 20px;
    }

    .master-volume {
        max-width: 100%;
        width: 100%;
    }

    .sounds-grid {
        grid-template-columns: repeat(2, 1fr);
    }

    .timer-options {
        flex-wrap: wrap;
    }
}

@media (max-width: 480px) {
    .sounds-grid {
        grid-template-columns: 1fr;
    }

    .sound-card {
        padding: 20px;
    }

    .timer-btn {
        padding: 8px 16px;
        font-size: 0.9rem;
    }
}