:root {
  --card-bg: rgba(255, 255, 255, 0.7);
  --header-bg: rgba(255, 255, 255, 0.6);
  --main-padding: 20px;
}
body {
  margin: 0;
  background: linear-gradient(
      rgba(255, 255, 255, 0.1),
      rgba(255, 255, 255, 0.1)
    ),
    url("picture/dt.png") center/cover no-repeat fixed;
  min-height: 100vh;
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", Arial, sans-serif;
  color: #222;
}
header {
  margin: 0;
  box-shadow: 0 2px 10px rgba(0, 0, 0, 0.08);
  background-color: var(--header-bg);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 10px;
  height: 80px;
}
.top-box-l h2 {
  margin: 0;
  font-size: 1.6rem;
  letter-spacing: 2px;
}
.top-box-r {
  display: flex;
  align-items: center;
  gap: 10px;
  padding-top: 10px;
  margin: 0;
  width: auto;
}
.top-box-r > div {
  display: flex;
  align-items: center;
  margin: 0;
}
.top-box-r p {
  margin: 0 0 0 4px;
  font-size: 0.98em;
  display: inline;
}
a {
  text-decoration: none;
  color: #222;
  display: flex;
  align-items: center;
  transition: color 0.2s;
}
a:hover {
  color: #1976d2;
}
.announcement {
  background-color: var(--card-bg);
  border-radius: 15px;
  padding: var(--main-padding);
  margin: 30px 30px 0 30px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
}
.announcement h1 {
  margin: 0 0 10px 0;
  font-size: 1.5rem;
}
.card {
  display: block;
  background-color: var(--card-bg);
  border-radius: 15px;
  padding: var(--main-padding);
  margin: 20px 30px 0 30px;
  box-shadow: 0 2px 8px rgba(0, 0, 0, 0.04);
}
.card h3 {
  margin: 0 0 10px 0;
  font-size: 1.15rem;
}
.home,
.document-center,
.github,
.download,
.qq,
.login,
.question,
.about .sponsor {
  margin: 0 4px;
  float: none;
  padding: 0;
}
.footer {
  background: var(--header-bg);
  padding: 2rem 1rem;
  text-align: center;
  margin-top: 3rem;
  border-top: 1px solid #eee;
  font-size: 0.98em;
}
.footer p {
  margin: 0.5rem 0;
  color: #000;
  font-size: 0.95em;
}
@media (max-width: 800px) {
  .announcement,
  .card {
    max-width: 98vw;
    margin-left: 1vw;
    margin-right: 1vw;
  }
  .top-box-r {
    flex-wrap: wrap;
    gap: 6px;
    padding-top: 6px;
  }
}
@media (max-width: 600px) {
  header {
    flex-direction: column;
    align-items: flex-start;
    padding: 0 4px;
  }
  .top-box-l h2 {
    font-size: 1.2rem;
  }
  .top-box-r {
    width: 100%;
    justify-content: flex-start;
    gap: 4px;
    padding-top: 2px;
  }
}