style.css

:root {
  --main-color: #f3df49;
  --text-color: #000;
  --bkg-color: #fff;
}

body.dark-theme {
  --main-color: #f3df49;
  --text-color: #fff;
  --bkg-color: #111;
}

/**
 * Minified by jsDelivr using clean-css v4.1.11.
 * Original file: /npm/modern-normalize@0.5.0/modern-normalize.css
 * 
 * Do NOT use SRI with dynamically generated files! More information: https://www.jsdelivr.com/using-sri-with-dynamic-files
 */
/*! modern-normalize | MIT License | https://github.com/sindresorhus/modern-normalize */
html {
  box-sizing: border-box;
}
*,
::after,
::before {
  box-sizing: inherit;
}
:root {
  -moz-tab-size: 4;
  tab-size: 4;
}
html {
  line-height: 1.15;
  -webkit-text-size-adjust: 100%;
}
body {
  margin: 0;
}
body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica,
    Arial, sans-serif, "Apple Color Emoji", "Segoe UI Emoji", "Segoe UI Symbol";
}
hr {
  height: 0;
}
abbr[title] {
  text-decoration: underline dotted;
}
b,
strong {
  font-weight: bolder;
}
code,
kbd,
pre,
samp {
  font-family: SFMono-Regular, Consolas, "Liberation Mono", Menlo, Courier,
    monospace;
  font-size: 1em;
}
small {
  font-size: 80%;
}
sub,
sup {
  font-size: 75%;
  line-height: 0;
  position: relative;
  vertical-align: baseline;
}
sub {
  bottom: -0.25em;
}
sup {
  top: -0.5em;
}
button,
input,
optgroup,
select,
textarea {
  font-family: inherit;
  font-size: 100%;
  line-height: 1.15;
  margin: 0;
}
button,
select {
  text-transform: none;
}
[type="button"],
[type="reset"],
[type="submit"],
button {
  -webkit-appearance: button;
}
[type="button"]::-moz-focus-inner,
[type="reset"]::-moz-focus-inner,
[type="submit"]::-moz-focus-inner,
button::-moz-focus-inner {
  border-style: none;
  padding: 0;
}
[type="button"]:-moz-focusring,
[type="reset"]:-moz-focusring,
[type="submit"]:-moz-focusring,
button:-moz-focusring {
  outline: 1px dotted ButtonText;
}
fieldset {
  padding: 0.35em 0.75em 0.625em;
}
legend {
  padding: 0;
}
progress {
  vertical-align: baseline;
}
[type="number"]::-webkit-inner-spin-button,
[type="number"]::-webkit-outer-spin-button {
  height: auto;
}
[type="search"] {
  -webkit-appearance: textfield;
  outline-offset: -2px;
}
[type="search"]::-webkit-search-decoration {
  -webkit-appearance: none;
}
::-webkit-file-upload-button {
  -webkit-appearance: button;
  font: inherit;
}
summary {
  display: list-item;
}

/**
  Utilities

**/

.visuallyhidden {
  border: 0;
  clip: rect(0 0 0 0);
  clip-path: inset(50%);
  height: 1px;
  margin: -1px;
  overflow: hidden;
  padding: 0;
  position: absolute;
  width: 1px;
  white-space: nowrap; /* 1 */
}

.hide-content {
  text-indent: -9999px;
}

/**
  Commons
**/

html {
  font-family: "Open Sans", sans-serif;
  font-size: 11px;
}

body {
  margin: 0;
  padding: 0;
  color: var(--text-color);
  background: var(--bkg-color);
}

a {
  color: var(--text-color);
  text-decoration: none;
}

a:hover {
  color: #333;
}

.dark-theme a:hover {
  color: var(--main-color);
}

/**

**/

header {
  display: flex;
  flex-direction: column;
  align-items: center;
  background: var(--main-color) url(img/big-logo.svg) no-repeat;
  background-position: calc(100vw - 1160px + 30px) 90%;
  background-size: 1160px;

  text-align: center;
  margin-bottom: 5rem;
}

.dark-theme header {
  background-color: #000;
}

.header__title {
  width: 179px;
  height: 179px;

  background: url(img/header-logo.svg) no-repeat center center;
  background-size: contain;
}

.dark-theme .header__title {
  background: var(--main-color);
  -webkit-mask: url(img/header-logo.svg) no-repeat center;
  mask: url(img/header-logo.svg) no-repeat center;
}

.header__intro {
  max-width: 640px;
  margin: 0 0 2rem;
  font-size: 3rem;
  font-weight: 700;
}

.header__subintro {
  max-width: 640px;
  margin: 0 0 4rem;
  font-size: 2rem;
}

.follow-us {
  font-size: 2rem;
  text-align: center;
  margin-bottom: 5rem;
}

.follow-us__slack-counter {
  vertical-align: bottom;
}

.follow-us__socials {
  display: flex;
  justify-content: space-between;
  align-items: center;
  width: 400px;
  margin: 0 auto;
  padding: 0;
}
.follow-us__socials li {
  background: transparent no-repeat center center;
  background-size: contain;
  list-style: none;
  margin: 0;
  width: 100px;
  height: 100px;
  /* background: red; */
}

.follow-us__socials li a {
  display: block;
  width: 100%;
  height: 100%;
}

li.follow-us__socials--slack {
  background-image: url(img/social-slack.svg);
  width: 60px;
  height: 60px;
}

li.follow-us__socials--meetup {
  background-image: url(img/social-meetup.svg);
  width: 81px;
  height: 77px;
}

li.follow-us__socials--twitter {
  background-image: url(img/social-twitter.svg);
  width: 60px;
  height: 60px;
}

li.follow-us__socials--facebook {
  background-image: url(img/social-facebook.svg);
  width: 55px;
  height: 55px;
}

li.follow-us__socials--github {
  background-image: url(img/social-github.svg);
  width: 60px;
  height: 60px;
}

li.follow-us__socials--youtube {
  background-image: url(img/social-youtube.svg);
  width: 60px;
  height: 60px;
}

/**
    Events
**/

.events {
  text-align: center;
}

.events__intro {
  font-size: 3rem;
  line-height: 4rem;
  width: 70vw;
  margin: 0 auto;
  margin-bottom: 3rem;
}

.events__grid {
  display: flex;
  flex-wrap: wrap;
  margin: 1.5rem;
  width: 996px;
  margin: 0 auto;
  margin-bottom: 5rem;
}

.events_title {
  display: inline-block;
  font-size: 4rem;
  padding: 0.1rem 1rem;
  padding-bottom: 0.6rem;
  color: #000;
  background-color: var(--main-color);
}

.events__event {
  --bkg-color: #f7f7f7;
  --text-color: #000;
  justify-content: space-around;
  display: flex;
  flex-direction: column;
  width: 312px;
  height: 312px;
  font-size: 2rem;
  text-align: left;
  padding: 2rem;
  margin: 10px;
  color: var(--text-color);
  background: var(--bkg-color);
}

.dark-theme .events__event {
  --bkg-color: #000;
  --text-color: #f7f7f7;
}

.events__event h3 {
  margin: 0;
  /* padding: 0; */
  flex-grow: 1;
}

.events__event-date {
  margin-bottom: 1rem;
}

.events__event--next {
  color: white;
  background-color: #ec1c40;
  background-image: url(img/event-next.svg);
  background-position: 130% 120%;
  background-repeat: no-repeat;
  background-size: 80%;
  width: 644px;
  justify-content: space-evenly;
}

.events__event--double {
  width: 644px;
  justify-content: space-evenly;
}

.events__content {
  flex-grow: 1;
}

.footer-follow-us {
  --bkg-color: #ebebeb;
  color: --text-color;
  background-color: var(--bkg-color);
  font-size: 2rem;
  text-align: center;
  padding: 2rem 1rem;
}

.footer-follow-us br {
  display: none;
}

.dark-theme .footer-follow-us {
  --bkg-color: #000;
}

footer a {
  font-weight: 700;
}

.supported-by {
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 2rem 0;
  text-align: center;
  color: var(--text-color);
}

.dark-theme .supported-by {
  --text-color: var(--bkg-color);
  background-color: var(--main-color);
}

.supported-by ul {
  display: flex;
  align-items: center;
  margin: 0;
  padding: 0;
}

.supported-by h3 {
  font-weight: normal;
  text-transform: lowercase;
  font-size: 1.7rem;
}

.supported-by li {
  display: inline-block;
  background: transparent no-repeat center center;
  background-size: contain;
  list-style: none;
  margin: 0 15px;
  width: 100px;
  height: 100px;
}

.supported-by li a {
  display: block;
  width: 100%;
  height: 100%;
}

li.supported-by--spazio01 {
  background-image: url(img/spazio01.png);
  width: 190px;
}

li.supported-by--jetbrains {
  background-image: url(img/jetbrains-logo.svg);
  /* width: 60px;
    height: 60px; */
}

li.supported-by--grusp {
  background-image: url(img/grusp-logo.svg);
  height: 85px;
}

.btn-toggle-theme {
  position: absolute;
  top: 2rem;
  right: 2rem;
  background: none;
  border: none;
  cursor: pointer;
  color: var(--text-color);
  opacity: 0.4;
}
.btn-toggle-theme .text {
  display: none;
}

@media screen and (max-width: 1023px) {
  .events__grid {
    width: 664px;
  }
}

@media screen and (max-width: 767px) {
  .header__intro {
    font-size: 2.3rem;
  }

  .header__subintro {
    font-size: 2rem;
    margin-right: 2rem;
    margin-left: 2rem;
  }

  .follow-us {
    padding: 0 2rem;
  }
  .follow-us__socials {
    width: 100%;
    padding: 0 10px;
  }

  .events__intro {
    width: 100%;
    padding: 2rem;
    font-size: 3rem;
    line-height: 3.6rem;
  }

  .events__grid {
    width: 100%;
    padding: 0 10px;
  }

  .events__event {
    width: 100%;
    height: auto;
  }

  .supported-by {
    display: block;
  }

  .footer-follow-us br {
    display: block;
  }
}