*, *::before, *::after { box-sizing: border-box; }

body {
  font-family: 'Inter', -apple-system, system-ui, sans-serif;
  background: linear-gradient(160deg, #f8f6ff 0%, #f5f5f7 40%, #f0f4fd 100%);
  margin: 0;
  padding: 0;
  color: #3a3a3a;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

.play-nav {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 100;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 0.7rem 2rem;
  background: rgba(255, 255, 255, 0.78);
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  border-bottom: 1px solid rgba(0, 0, 0, 0.07);
}

.play-nav .back-link {
  display: inline-flex;
  align-items: center;
  gap: 0.35rem;
  font-size: 0.82rem;
  font-weight: 500;
  color: #7a7a7a;
  text-decoration: none;
  transition: color 0.3s ease;
}

.play-nav .back-link:hover { color: #5b5ea6; }

.play-nav .back-link svg {
  width: 16px;
  height: 16px;
  flex-shrink: 0;
}

.play-nav .nav-links {
  display: flex;
  gap: 0.4rem;
  list-style: none;
  margin: 0;
  padding: 0;
  align-items: center;
}

.play-nav .nav-links li a {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: 0.25rem 0.75rem;
  border-radius: 6px;
  font-size: 0.78rem;
  font-weight: 600;
  color: #7a7a7a;
  text-decoration: none;
  transition: all 0.25s ease;
}

.play-nav .nav-links li a:hover {
  background: rgba(91, 94, 166, 0.08);
  color: #5b5ea6;
}

.play-nav .nav-links li a.active {
  background: #5b5ea6;
  color: #fff;
}

.play-nav .nav-links .nav-sep {
  width: 1px;
  height: 16px;
  background: rgba(0, 0, 0, 0.1);
  margin: 0 0.4rem;
}

.play-wrapper {
  max-width: 1100px;
  margin: 0 auto;
  padding: 5rem 2rem 3rem;
}

.play-header {
  text-align: center;
  margin-bottom: 2.5rem;
}

.play-header h1 {
  font-family: 'Fraunces', Georgia, serif;
  font-size: clamp(1.8rem, 4vw, 2.4rem);
  font-weight: 700;
  color: #1a1a1a;
  margin: 0 0 0.6rem;
  line-height: 1.2;
}

.play-header h1 em {
  font-style: italic;
  color: #5b5ea6;
}

.play-header p {
  font-size: 0.95rem;
  color: #7a7a7a;
  margin: 0;
}

h2 {
  font-family: 'Fraunces', Georgia, serif;
  font-size: 1.15rem;
  font-weight: 700;
  color: #1a1a1a;
  margin: 0 0 0.15rem;
  border-bottom: none;
  padding-bottom: 0;
}

p.note {
  font-size: 0.82rem;
  color: #888;
  font-style: normal;
  margin-bottom: 1.2rem;
  line-height: 1.6;
}

p.note code {
  font-size: 0.78rem;
  background: rgba(91, 94, 166, 0.08);
  color: #5b5ea6;
  padding: 0.15em 0.45em;
  border-radius: 4px;
}

.section {
  margin-bottom: 1.5rem;
  padding: 1.6rem 1.8rem;
  background: rgba(255, 255, 255, 0.8);
  backdrop-filter: blur(8px);
  border: 1px solid rgba(0, 0, 0, 0.06);
  border-radius: 12px;
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.03);
  transition: box-shadow 0.3s ease;
}

.section:hover {
  box-shadow: 0 6px 24px rgba(0, 0, 0, 0.06);
}

.section-featured {
  border: 2px solid rgba(91, 94, 166, 0.2);
  background: rgba(255, 255, 255, 0.9);
}

.section-featured h2 {
  color: #5b5ea6;
  font-size: 1.3rem;
}

.section-featured #container {
  margin: 0 auto;
}

.grid-row {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 1.2rem;
}

.grid-row .section {
  margin-bottom: 0;
}

.square, .circle {
  width: 100px;
  height: 100px;
  display: inline-block;
}

.circle {
  border-radius: 50%;
}

.blockRed {
  background-color: red;
}

.blockYellow {
  background-color: yellow;
}

.blockGreen {
  background-color: #2ecc71;
}

.blockBlue {
  background-color: #3498db;
}

#container {
  background-color: pink;
  margin: 0 auto;
  padding: 0;
  width: 400px;
  height: 400px;
  border-radius: 8px;
}

.experiment-inline-block .square,
.experiment-inline-block .circle {
  display: inline-block;
}

.experiment-block .square,
.experiment-block .circle {
  display: block;
}

.experiment-float-left .square,
.experiment-float-left .circle {
  float: left;
}

.experiment-float-left::after {
  content: "";
  display: table;
  clear: both;
}

.pos-relative-box {
  position: relative;
  width: 100%;
  height: 300px;
  background-color: #ecf0f1;
  border: 1px solid rgba(0, 0, 0, 0.08);
  border-radius: 8px;
}

.pos-relative-box .square,
.pos-relative-box .circle {
  position: absolute;
}

.pos-relative-box .blockRed {
  top: 20px;
  left: 20px;
}

.pos-relative-box .blockYellow {
  top: 60px;
  left: 140px;
}

.pos-relative-box .blockGreen {
  top: 150px;
  left: 80px;
}

.pos-relative-box .blockBlue {
  top: 100px;
  left: 260px;
  border-radius: 50%;
}

.texture-demo {
  width: 200px;
  height: 200px;
  display: inline-block;
  background-size: cover;
  background-position: center;
  border: 1px solid rgba(0, 0, 0, 0.08);
  border-radius: 8px;
  margin-right: 10px;
  vertical-align: top;
  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.06);
}

.blockWood {
  background-image: url('https://images.pexels.com/photos/172276/pexels-photo-172276.jpeg?auto=compress&cs=tinysrgb&w=400');
  background-size: cover;
}

.blockStone {
  background-image: url('https://images.pexels.com/photos/1314466/pexels-photo-1314466.jpeg?auto=compress&cs=tinysrgb&w=400');
  background-size: cover;
}

@media (max-width: 700px) {
  .play-nav { padding: 0.6rem 1rem; }
  .play-nav .nav-links .nav-sep,
  .play-nav .nav-links li a.nav-portfolio { display: none; }
  .play-wrapper { padding: 4.5rem 1rem 2rem; }
  .section { padding: 1.2rem; }
  #container { width: 100%; height: auto; min-height: 400px; }
  .pos-relative-box { width: 100%; }
  .texture-demo { width: 45%; margin-bottom: 10px; }
  .grid-row { grid-template-columns: 1fr; }
}