#customContent {
  display: flex;
  justify-content: center;
  align-items: center;
  height: calc(100vh - 300px);
}

body.light {

--bg: #f6f6f6;
--panel: #ffffff;
--text: #111;
--border: #dcdcdc;
--accent: #2a6df4;

}

body {

margin: 0;
font-family: Arial, Helvetica, sans-serif;

background: var(--bg);
color: var(--text);

}

header {

display: flex;
justify-content: space-between;
align-items: center;

padding: 16px 24px;

background: var(--panel);

}