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

body {
    background-color: salmon;
    padding-bottom: 500px;
}

/*
CSS ruleset aka rule

selector {
    declaration 1;
    property1: value;
    property2: value value;
}
*/

/* type selector */
h1 {
    text-align: center;
    color: #EEE;
    border: #234;
    border-width: 8px;
    border-style: groove;
    margin: 24px;  /* outside of the border */
    margin-bottom: 100px;
    padding: 16px; /* inside of the border */
    /* create stripes as a background */
    background-image: 
        repeating-linear-gradient(140deg, #222, #222 30px, #234 31px, #234 60px, #222 61px);
        position: relative; /* if you want to position a child */
}

/* descendent selector */
h1 span {
    position: absolute; bottom: -60px; right: 50px;
}

/* ID selector and a grouped selctor */
#div1, #div2 {
    width: 600px; height: 100px;
    border: 20px solid darkred;
    margin: 50px auto;
}

#div2 {
    width: 200px; height: 200px;
    border: 8px solid darkred;
    transform: rotate(45deg);
}

/* class selector */
.but1 {
    padding: 12px 16px;
    background-color: #eee; color: #222;
    border: 2px solid darkred;
    margin: 8px;
}

.but2 {
    display: block;
    width: 100px; height: 100px;
    border-radius: 50%;
    margin: 10px auto;
    background-color: #ffc;
    text-align: center;
    line-height: 100px;
}

dt {
    font-weight: bold;
    margin-left: 100px;
    font-size: 120%;
    margin-top: 20px;
}

dd{
    margin-left: 30px;
    font-style: italic;
}

dd ul {
    margin-left: 30px;
}