.input-amedida {
    font-size: 18px;
    /*max-width:100px;*/
    padding: 10px 10px 10px 5px;
    display: block;
    border: none;
    background-color: transparent;
    border-bottom: 1px solid #757575;
}

    .input-amedida:focus {
        outline: none;
    }

.float-label {
    color: #999;
    font-size: 15px;
    font-weight: normal;
    position: absolute;
    pointer-events: none;
    left: 1.5em;
    top: 10px;
    transition: 0.2s ease all;
    -moz-transition: 0.2s ease all;
    transition: background-size 0.4s cubic-bezier(0.64, 0.09, 0.1, 1);
    -webkit-transition: 0.2s ease all;
}

.borde-amedida {
    border: none;
    border-bottom: 1px solid #757575;
    -webkit-box-shadow: none;
    box-shadow: none;
    max-height: 2em;
    width: 100%;
    border: 0;
    padding: 10px 5px;
    background: transparent no-repeat;
    background-image: linear-gradient(to bottom, #db3c3c, #db3c3c), linear-gradient(to bottom, silver, silver);
    background-size: 0 2px, 100% 1px;
    background-position: 50% 100%, 50% 100%;
    transition: background-size 0.4s cubic-bezier(0.64, 0.09, 0.1, 1);
}

    .borde-amedida:focus {
        border: none;
        border-bottom: 0px solid #0000ff;
        -webkit-box-shadow: none;
        box-shadow: none;
        background-size: 100% 2px, 100% 1px;
        outline: none;
    }

.float-label-activo {
    top: -0.6em;
    font-size: 12px;
    font-weight: 600;
    left: 4px;
}

.input-amedida:focus ~ .float-label {
    color: #db3c3c;
}