:root {
  --text-white: #f5f5f5;
  --bg-black: #18314f;
  --bg-blue: #6990f6;
}

body {
  background-color: var(--bg-black);
}

main {
  max-width: 1024px;
  margin: 0 auto;
  color: var(--text-white);
}

.game {
  width: 100%;
  min-height: 440px;
  overflow: hidden;
  position: relative;
  background-image: url('./assets/background.png');
  background-size: 600px 500px;
  background-position: center;
}

.mario {
  width: 65px;
  height: 65px;
  position: absolute;
  left: 20px;
  z-index: 1;
}

.obstacle {
  background-size: 100%;
  background-repeat: no-repeat;
  position: absolute;
  bottom: 0;
  width: 50px;
  height: 49px;
}

.spin {
  animation: spin 2s linear infinite;
}

@keyframes spin {
  from {
    transform: rotateY(0deg);
  }
  to {
    transform: rotateY(360deg);
  }
}

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

.button-group {
  display: flex;
  gap: 4px;
}

.button-group > button {
  font-size: 0.8rem;
  cursor: pointer;
}

.audio-toggle {
  border: none;
  padding: 0;
  margin: 0 0 0 4px;
  text-decoration: none;
  background-color: transparent;

  width: 20px;
  height: auto;
  background-image: url('./assets/sound-off.png');
  background-size: cover;
  background-repeat: no-repeat;
}

.github-link {
  background: none;
  border: none;
  padding: 0;
  text-decoration: none;
}

.github-link > img {
  width: 28px;
  height: auto;
}

.control {
  background-color: var(--bg-blue);
  border-bottom: #5c84f5 1px solid;
  display: flex;
  align-items: center;
  padding: 0 1rem;
}

.score-heading {
  width: fit-content;
  margin-left: auto;
}

.score-heading > .score {
  display: inline-block;
  transition: transform 0.3s ease;
}

aside > .guide {
  padding: 6px 0;
  display: flex;
  align-items: center;
  gap: 4px;
}

kbd {
  background-color: var(--text-white);
  border-radius: 3px;
  border: 1px solid #b4b4b4;
  box-shadow:
    0 1px 1px rgba(0, 0, 0, 0.2),
    0 2px 0 0 rgba(255, 255, 255, 0.7) inset;
  color: #333;
  display: inline-block;
  font-size: 0.85em;
  font-weight: 700;
  line-height: 1;
  padding: 2px 4px;
  white-space: nowrap;
}

.dialog-failed::backdrop {
  background: rgba(0, 0, 0, 0.33);
  backdrop-filter: blur(4px);
}

.dialog-failed form {
  width: 200px;
  text-align: center;
}