style.css

:root {
  --defaultColor: #5ee084;
  --backgroundColor: #20262e;
  --defaultHoverColor: #3D7F51;
  --themeSwitchColor: #FBFBFB;
}

[data-theme="light"] {
  --defaultColor: #20262e;
  --backgroundColor: #FBFBFB;
  --defaultHoverColor: #F48816;
  --themeSwitchColor: #20262e;
}

body {
  background: var(--backgroundColor);
  margin: 0;
  padding: 0;
  font-family: 'Roboto Mono', monospace;
  color: var(--defaultColor);
  transition: all 600ms ease-in-out;
}

#content {
  margin: 1em;
}

h1 {
  margin-top: 1em;
  margin-bottom: 2em;
}

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

.cards {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 30px;
    margin: 30px;
}

.card {
  width: 300px;
  height: 150px;
  border: 3px solid var(--defaultColor);
  border-radius: 10px 20px 0 20px;
  box-shadow: 5px 5px var(--defaultColor);
  position: relative;
}

.card h2 {
  font-size: 24px;
  margin-top: 35px;
  margin-left: 35px;
}

.card .footer {
  color: var(--defaultColor);
  font-size: 14px;
  position: absolute;
  bottom: 5px;
  left: 15px;
  width: 90%;
  display: flex;
  justify-content: space-between;
  align-items: baseline;
}

.card .footer>.right {
  font-size: 28px;
}

.card:hover {
  cursor: pointer;
  border-color: var(--defaultHoverColor);
  box-shadow: 5px 5px var(--defaultHoverColor);
}

.card:active {
  position: relative;
  top: 2px;
  box-shadow: 1px 1px var(--defaultHoverColor);
}

.themeSwitch {
  position: fixed;
  right: 10px;
  bottom: 5px;
}

.dot {
  height: 1em;
  width: 1em;
  background-color: var(--themeSwitchColor);
  border-radius: 50%;
  display: inline-block;
  cursor: pointer;
}

@media screen and (min-width: 1200px) {

  #content {
    width: 50%;
    margin-left: auto;
    margin-right: auto;
  }

}