the callouts from the bootstrap documentation

docs style (bootstrap)

/* Side notes for calling out things
-------------------------------------------------- */

/* Base styles (regardless of theme) */
.bs-callout {
  margin: 20px 0;
  padding: 15px 30px 15px 15px;
  border-left: 5px solid #eee;
}
.bs-callout h4 {
  margin-top: 0;
}
.bs-callout p:last-child {
  margin-bottom: 0;
}
.bs-callout code,
.bs-callout .highlight {
  background-color: #fff;
}

/* Themes for different contexts */
.bs-callout-danger {
  background-color: #fcf2f2;
  border-color: #dFb5b4;
}
.bs-callout-warning {
  background-color: #fefbed;
  border-color: #f1e7bc;
}
.bs-callout-info {
  background-color: #f0f7fd;
  border-color: #d0e3f0;
}

nice thanks for it :)

the corrected code, with bootstrap5 shortcodes support:

/* Side notes for calling out things /
/ Base styles (regardless of theme) /
.bs-callout {
padding: 1.25rem;
margin-top: 1.25rem;
border-left: 0.25rem solid var(--bd-callout-border, var(--bs-gray-300));
background-color: var(--bd-callout-bg, var(--bs-gray-100));
}
.bs-callout h4 {
margin-top: 0;
}
.bs-callout p:last-child {
margin-bottom: 0;
}
.bs-callout code,
.bs-callout .highlight {
background-color: var(--bs-gray-100);
}
/ Themes for different contexts */
.bs-callout-danger {
--bd-callout-bg: rgba(var(--bs-danger-rgb), .075);
--bd-callout-border: rgba(var(--bs-danger-rgb), .5);
}
.bs-callout-warning {
--bd-callout-bg: rgba(var(--bs-warning-rgb), .075);
--bd-callout-border: rgba(var(--bs-warning-rgb), .5);
}
.bs-callout-info {
--bd-callout-bg: rgba(var(--bs-info-rgb), .075);
--bd-callout-border: rgba(var(--bs-info-rgb), .5);
}