versionA.css

/* By HUNG WAI MAN 1155085664 */
* {
    color:darkslategrey;
}
html,body {
    margin: 0;
    padding: 0;
    text-align: center;
    font-family: 'Lacquer', sans-serif;
    font-family: 'Shadows Into Light', cursive;
}

#intro {
    width: 100%;
    border: 1px solid black;
    display: flex;
    flex-wrap: wrap;
    align-items: flex-start;
    align-content: flex-start;
}
#intro div div {
    padding:1px;
    margin:1px;
}
.flex-left {
    text-align: right;
}

.mp-0 {
    margin: 0;
}

.flex-right {
    display: flex;
    flex-direction: column;
    align-items: flex-start;
    align-content: flex-start;
}

.flex-right * {
    padding:1px;
    margin:1px;
}

#intro img {
    height: auto;
}


table {
    border-collapse: collapse;
}

table, td, th {
    border: 1px solid green;
}

#main {
    margin: 8px auto 8px auto;
    text-align: left;
    max-width: 1000px;

}

header {
    background-image: url('header-bg.png');
    background-repeat: no-repeat;
    background-size: cover;
    height: 200px;
    width: 100vw;
    display: table-cell; 
    vertical-align: bottom;
    border-bottom: 5px solid green;
    margin-bottom: 8px;

}

img {
    max-width: 100%;
    height: auto;
}

footer {
    margin: 30px;
}

#hash {
    display: flex;
    flex-wrap: wrap;
}

#hash span{
    flex: 1 1 50%;
    text-align: center;
}

#nav,nav {
    padding: 16px;
    width: 100vw;
    text-align: center;
    vertical-align: bottom;
}


#nav span {
    width: 25%;
}
#nav > nav > span > a {
    color: white;
    margin-left: 16px;
    margin-right: 16px;
    text-decoration: none;
}

#nav > nav > span > a:hover {
    color: yellow;
    text-decoration: underline;
    transition: 300ms;
    
}

header h1, header h3 {
    color: white;
    text-align: center;
    padding: 0;
    margin: 0;
}

/* For mobile phones: */
.d-none { 
    display: none;
}

.d-table-cell { 
    display: table-cell;
}
  
@media only screen and (min-width: 500px) {
    /* For tablets: */
    .d-s-table-cell {display: table-cell}
    .d-s-none { 
        display: none;
    }
}


/* For mobile phones: */
[class*="col-"] {
    width: 100%;
  }

  @media only screen and (min-width: 500px) {
    /* For tablets: */
    .col-s-1 {width: 8.33%;}
    .col-s-2 {width: 16.66%;}
    .col-s-3 {width: 25%;}
    .col-s-4 {width: 33.33%;}
    .col-s-5 {width: 41.66%;}
    .col-s-6 {width: 50%;}
    .col-s-7 {width: 58.33%;}
    .col-s-8 {width: 66.66%;}
    .col-s-9 {width: 75%;}
    .col-s-10 {width: 83.33%;}
    .col-s-11 {width: 91.66%;}
    .col-s-12 {width: 100%;}
  }