:root {
  --title-color: #2970ea;
  --subtitle-color: #577;

  --night-title: #7aa8ff;
  --night-subtitle: #9bb0d8;
}
.article-container {
  max-width: 900px;
  margin: 40px auto;
  padding: 28px;
  background: var(--card-bg);
  border-radius: 20px;
  backdrop-filter: blur(10px);
  box-shadow: 0 4px 18px rgba(41,112,234,0.17);
  position: relative;
  z-index: 1;
}
body.night .article-container {
  background: var(--night-card-bg);
  box-shadow: 0 4px 18px rgba(5,8,18,0.7);
}

.article-title {
  margin-top: 0;
  font-size: 2em;
  color: var(--title-color);
}
body.night .article-title {
  color: var(--night-title);
}

.article-date {
  color: #666;
  margin-bottom: 20px;
}
body.night .article-date {
  color: #9bb0d8;
}

.article-content {
  font-size: 1.1em;
  line-height: 1.8em;
  color: var(--text-color);
}
body.night .article-content {
  color: var(--night-text);
}

.return-btn-warpper{
  max-width: 900px;
  margin: 0px auto;
}
.return-btn-warpper .return-btn {
  margin-top: 30px;
  display: inline-block;
  padding: 10px 18px;
  background: rgba(255,255,255,0.55);
  backdrop-filter: blur(8px);
  border-radius: 12px;
  font-size: 1.05em;
  cursor: pointer;
  color: #2970ea;
  border: 1px solid rgba(255,255,255,0.5);
  transition: 0.25s;
}
body.night .return-btn {
  background: rgba(40,40,60,0.55);
  color: #7aa8ff;
  border: 1px solid rgba(255,255,255,0.2);
}