body    { font-size: 1em; line-height: 1.5em; font-family: system-ui, Helvetica, sans-serif; margin: 2em auto; max-width: 35em; }
hr      { height: 1px; background-color: #efefef; border: 0; margin: 0; padding: 0; }
ul      { list-style-type: square; }
h1      { line-height: 1.2em; }
.header { padding: 5px; }
.main   { padding: 5px; }
.footer { padding: 5px; color: #333; text-align: right; }
.left   { float: left; }
.right  { float: right; }