Same code, same header... different header sizes in different pages???

/*************************************
GENERAL
**************************************/

body {
    font-family: 'Open Sans', sans-serif;
}

#wrapper {
    max-width: 940px;
    margin: 0 auto;
    padding: 0 5%;
}

a {
    text-decoration: none;
}

img {
    max-width: 100%;

}

h3 {
    margin: 0 0 1em 0;
}



/*************************************
HEADING
**************************************/
header {
    float: left;
    margin: 0 0 30px 0; /*margen para abajo*/
    padding: 5px 0 0 0; /*pequeño margen de arriba*/
    width: 100%; /*se pone esta para que salga completo el header*/

}


#logo {
    text-align: center;
    margin: 0;
}

h1{
    font-family: 'Changa One', sans-serif;
    margin: 15px 0;
    font-size: 1.75em;
    font-weight: normal;
    line-height: 0.8em;
}

h2 {
    font-size: 0.75em;
    margin: -5px 0 0;
    font-weight: normal;
}




/************************************
NAVIGATION
*************************************/

nav {
    text-align: center;
    padding: 10px 0;
    margin: 20px 0 0;
}

nav ul {
    list-style: none;
    margin: 0 10px;
    padding: 0;
}

nav li{
    display: inline-block; /*pone las opciones para navegar en linea*/
}

nav a {
    font-weight: 800; /*hace las letras negritas y rellenas*/
    padding: 15px 10px; /*CENTRA el texto sin sacarlo de margen*/
}

/************************************
FOOTER
*************************************/

footer {
    font-size: 0.75em;
    text-align: center;
    clear: both; /* se acomodan los logos*/
    padding-top: 50px;
    color: #ccc;
}
/* El codigo en social-icon sirve para hacer los iconos mas pequeños*/
.social-icon {
    width: 20px;
    height: 20px;
    margin: 0 5px;
}


/*************************************
PAGE: PORTFOLIO
**************************************/

#gallery {
    margin: 0;
    padding: 0;
    list-style: none; /*bullet points off*/
}
/* Con esto se hacen dos columnas*/
#gallery li{
    float: left;
    width: 45%;
    margin: 2.5%;   
    background-color: #f5f5f5;
    color: #bdc3c7;
}

#gallery li a p{
    margin: 0;
    padding: 5%;
    font-size: 0..75em;
    color: #bdc3c7;
}

#gallery li a p:hover{
    color: #599A68;
}



/************************************
PAGE: ABOUT
*************************************/

.profile-photo {
    display: block;
    max-width: 150px;
    margin: 0 auto 30px;
    border-radius: 100%

}



/************************************
PAGE: CONTACT
*************************************/







/*************************************
COLORS
**************************************/

/* Site Body */
body {
    background-color: #fff;
    color: #999;
}

/*green header*/
header {
    background: #6AB47B;
    border-color: #599A68;
}

/*nav background on mobile*/
nav {
    background: #599A68;
}

/*logo text*/
h1, h2 {
    color: #fff;
}

/*links*/
a {
    color: #6AB47B;
}

/*nav link*/
nav a, nav a:visited {
    color: #fff;
}

/*selected nav link*/
nav a.selected, nav a:hover {
    color: #32673F;
}