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

body{
    font-size: 16px;
    --baseline: 22px;
    --unit: 20px;
    line-height: var(--baseline);
    font-family: Arial, Helvetica, sans-serif;
    max-width: 620px;
    margin: 30px auto;
    margin-bottom: 10vh;
   
}

header{
    border: 2px solid currentColor;
    text-align: center;
    padding: var(--unit); 
}

header p{
    font-weight: bold;
}

header h1{
    font-size: 1.6rem;
    line-height: calc(var(--baseline)*1.4);
    margin-bottom: calc(var(--baseline)*0.5);
}

.cours{
    margin-top: calc(var(--baseline)*4);
}

h2{
    font-size: 1.6rem;
    line-height: calc(var(--baseline)*1.4);
    border-bottom: 2px solid currentColor;
    margin-bottom: calc(var(--baseline)*1.5);
}

h3{
    margin-top: calc(var(--baseline)*2);
    margin-bottom: calc(var(--baseline)*0.75);
}

ul li, ol li{
    margin-top: calc(var(--baseline)*0.5);
}

code{
    background-color: #b3dfea;
    display: block;
    padding: 0.1ch 1ch;
    margin: calc(var(--baseline)*0.5) 0px;
}

p code, li code{
    display: inline-block;
}

p + p{
    margin-top: calc(var(--baseline)*0.5);
}

figure, img{
    width: 100%;
}