style.css

:root {
  --b-font-main: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto,
    Oxygen-Sans, Ubuntu, Cantarell, "Helvetica Neue", sans-serif;
  --b-font-mono: Consolas, Monaco, monospace;
  --b-txt: #2e3440;
  --b-bg-1: #fff;
  --b-bg-2: #eceff4;
  --b-line: #eceff4;
  --b-link: #bf616a;
  --b-btn-bg: #242933;
  --b-btn-txt: #fff;
  --b-focus: #88c0d0;
}
@media (prefers-color-scheme: dark) {
  :root {
    --b-txt: #eceff4;
    --b-bg-1: #2e3440;
    --b-bg-2: #3b4252;
    --b-line: #3b4252;
  }
}
*,
:after,
:before {
  box-sizing: border-box;
}
html:focus-within {
  scroll-behavior: smooth;
}
body {
  max-width: 70ch;
  padding: 0 1rem;
  margin: auto;
  background: var(--b-bg-1);
  font-family: var(--b-font-main);
  text-rendering: optimizeSpeed;
  line-height: 1.5;
  color: var(--b-txt);
  -moz-tab-size: 4;
  tab-size: 4;
  word-break: break-word;
  -webkit-tap-highlight-color: transparent;
  -webkit-text-size-adjust: 100%;
}
main {
    margin-bottom: 60px;
}
footer {
    text-align: center;
}
address,
audio,
blockquote,
dd,
details,
dl,
fieldset,
figure,
h1,
h2,
h3,
h4,
h5,
h6,
hr,
iframe,
ol,
p,
pre,
table,
ul,
video {
  margin: 0 0 1.5rem;
}
h1,
h2,
h3,
h4,
h5,
h6 {
  line-height: 1.25;
  margin-top: 2rem;
}
h1 {
  font-size: 2rem;
}
h2 {
  font-size: 1.5rem;
}
h3 {
  font-size: 1.25rem;
}
h4 {
  font-size: 1rem;
}
h5 {
  font-size: 0.875rem;
}
h6 {
  font-size: 0.75rem;
}
a {
  color: var(--b-link);
  text-decoration: none;
}
a:hover {
  text-decoration: underline;
}
img,
svg,
video {
  height: auto;
}
embed,
iframe,
img,
object,
svg,
video {
  max-width: 100%;
}
iframe {
  border-style: none;
}
abbr[title] {
  text-decoration: underline;
  text-decoration: underline dotted;
}
blockquote {
  margin-left: 0;
  padding: 0.5rem 0 0.5rem 1.5rem;
  border-left: 0.25rem solid var(--b-txt);
}
blockquote > :last-child {
  margin-bottom: 0;
}
small {
  font-size: 0.875rem;
}
sub,
sup {
  font-size: 0.75em;
  line-height: 0;
  position: relative;
  vertical-align: baseline;
}
sub {
  bottom: -0.25em;
}
sup {
  top: -0.5em;
}
hr {
  height: 0;
  overflow: visible;
  border: 0;
  border-bottom: 1px solid var(--b-line);
}
code,
kbd,
pre,
samp,
tt,
var {
  background: var(--b-bg-2);
  border-radius: 0.25rem;
  padding: 0.125rem 0.25rem;
  font-family: var(--b-font-mono);
  font-size: 0.875rem;
}
pre {
  padding: 1rem;
  border-radius: 0;
  overflow: auto;
  white-space: pre;
}
pre code {
  padding: 0;
}
details {
  display: block;
  padding: 0.5rem 1rem;
  background: var(--b-bg-2);
  border: 1px solid var(--b-line);
  border-radius: 0.25rem;
}
details > :last-child {
  margin-bottom: 0;
}
details[open] > summary {
  margin-bottom: 1.5rem;
}
summary {
  display: list-item;
  cursor: pointer;
  font-weight: 700;
}
summary:focus {
  box-shadow: none;
}
table {
  border-collapse: collapse;
  width: 100%;
  text-indent: 0;
}
table caption {
  margin-bottom: 0.5rem;
}
tr {
  border-bottom: 1px solid var(--b-line);
}
td,
th {
  padding: 0.5rem 0;
}
th {
  text-align: left;
}
dd,
ol,
ul {
  padding-left: 2rem;
}
li > ol,
li > ul {
  margin-bottom: 0;
}
fieldset {
  padding: 0.5rem 0.75rem;
  border: 1px solid var(--b-line);
  border-radius: 0.25rem;
}
legend {
  padding: 0 0.25rem;
}
label {
    font-weight: bold;
}
button,
input,
select,
textarea {
  margin: 0;
  margin-bottom: 10px;
  padding: 0.5rem 0.75rem;
  max-width: 100%;
  background: var(--b-bg-2);
  border: 0;
  border-radius: 0.25rem;
  font: inherit;
  line-height: 1.125;
  color: var(--b-txt);
}
input:not([size]):not([type="button" i]):not([type="submit" i]):not([type="reset" i]):not([type="checkbox" i]):not([type="radio" i]),
select {
  width: 100%;
}
[type="color" i] {
  min-height: 2.125rem;
}
select:not([multiple]):not([size]) {
  padding-right: 1.5rem;
  background-repeat: no-repeat;
  background-position: right 0.5rem center;
  -moz-appearance: none;
  -webkit-appearance: none;
  appearance: none;
}
textarea {
  width: 100%;
  resize: vertical;
}
textarea:not([rows]) {
  height: 8rem;
}
[type="button" i],
[type="reset" i],
[type="submit" i],
button {
  -webkit-appearance: button;
  display: inline-block;
  text-align: center;
  white-space: nowrap;
  background: var(--b-btn-bg);
  color: var(--b-btn-txt);
  border: 0;
  cursor: pointer;
  transition: opacity 0.25s;
}
[type="button" i]:hover,
[type="reset" i]:hover,
[type="submit" i]:hover,
button:hover {
  opacity: 0.75;
}
[type="button" i][disabled],
[type="reset" i][disabled],
[type="submit" i][disabled],
button[disabled] {
  opacity: 0.5;
}
progress {
  vertical-align: middle;
}
[type="search" i] {
  -webkit-appearance: textfield;
  outline-offset: -2px;
}
::-webkit-inner-spin-button,
::-webkit-outer-spin-button {
  height: auto;
}
::-webkit-input-placeholder {
  color: inherit;
  opacity: 0.5;
}
::-webkit-search-decoration {
  -webkit-appearance: none;
}
::-webkit-file-upload-button {
  -webkit-appearance: button;
  font: inherit;
}
::-moz-focus-inner {
  border-style: none;
  padding: 0;
}
:-moz-focusring {
  outline: 1px dotted ButtonText;
}
:-moz-ui-invalid {
  box-shadow: none;
}
[aria-busy="true" i] {
  cursor: progress;
}
[aria-controls] {
  cursor: pointer;
}
[aria-disabled="true" i],
[disabled] {
  cursor: not-allowed;
}
:focus,
details:focus-within {
  outline: none;
  box-shadow: 0 0 0 2px var(--b-focus);
}
@media (prefers-reduced-motion: reduce) {
  html:focus-within {
    scroll-behavior: auto;
  }
  *,
  :after,
  :before {
    animation-delay: -1ms !important;
    animation-duration: 1ms !important;
    animation-iteration-count: 1 !important;
    background-attachment: scroll !important;
    scroll-behavior: auto !important;
    transition-delay: 0 !important;
    transition-duration: 0 !important;
  }
}
select:not([multiple]):not([size]) {
  background-image: url("data:image/svg+xml;charset=utf-8,%3Csvg width='16' height='16' viewBox='0 0 20 20' xmlns='http://www.w3.org/2000/svg' fill='%232e3440'%3E%3Cpath d='M5 6l5 5 5-5 2 1-7 7-7-7 2-1z'/%3E%3C/svg%3E");
}
@media (prefers-color-scheme: dark) {
  select:not([multiple]):not([size]) {
    background-image: url("data:image/svg+xml;charset=utf-8,%3Csvg width='16' height='16' viewBox='0 0 20 20' xmlns='http://www.w3.org/2000/svg' fill='%23eceff4'%3E%3Cpath d='M5 6l5 5 5-5 2 1-7 7-7-7 2-1z'/%3E%3C/svg%3E");
  }
}

fieldset p {
    margin-bottom: 10px;
}
fieldset p:last-child, fieldset button:last-child {
    margin-bottom: 5px;
}

.hide-show {
    margin-left:-80px;
    margin-top: 6px;
    cursor: pointer;
    color: gray;
    user-select: none;
}