html {
  background-color: #1c1c1c;
}

html, body {
  color-scheme: dark;
}

::-webkit-scrollbar {
  width: 8px;
}
::-webkit-scrollbar-track {
  background: #1c1c1c;
}
::-webkit-scrollbar-thumb {
  background-color: #555;
  border-radius: 4px;
}

/* 暗色模式支持 */
:root {
  color-scheme: dark;
}

body {
  margin: 0;
  padding: 0;
  background: #1c1c1c;
  font-family: "MS Sans Serif", "Segoe UI", "Arial", sans-serif;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
  color: #e0e0e0;
}

.page-frame {
  max-width: 750px;
  height: 825px;
  margin: 13px auto 0 auto;
  padding: 60px 20px 40px;
  background: #2c2c2c;
  border: 2px solid #555555;
  box-shadow: inset -2px -2px #444444, inset 2px 2px #000000;
}

.site-header {
  margin-bottom: 40px;
}

.site-header h1 {
  font-size: 24px;
  color: #79a6e0;
  text-align: center;
  margin: 0;
  text-shadow: 1px 1px #000;
}

h2 {
  margin-bottom: 20px;
  color: #e0e0e0;
  text-decoration: underline;
}

.button-group {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 20px;
  padding: 10px;
  background: #3a3a3a;
  border: 2px solid #555555;
  box-shadow: inset -2px -2px #444444, inset 2px 2px #000000;
  margin-bottom: 60px;
}

.option-btn {
  transition: background 0.3s ease, transform 0.2s ease;
  flex: 1 1 40%;
  padding: 12px 10px;
  border: 2px solid;
  border-color: #555555 #000000 #000000 #555555;
  background: #3a3a3a;
  color: #ffffff;
  font-size: 16px;
  font-weight: bold;
  cursor: pointer;
  box-shadow: 1px 1px 0px #000;
  text-align: center;
  display: block;
  text-decoration: none;
}

.option-btn:hover {
  background: #4a4a4a;
  color: #ffffff;
  text-decoration: none;
}

.option-btn:active {
  border-color: #000000 #555555 #555555 #000000;
  background: #3a3a3a;
  transform: translateY(1px);
  box-shadow: none;
}

.description {
  font-size: 14px;
  background: #003366;
  color: #ffffff;
  padding: 15px;
  border: 2px solid #555555;
  box-shadow: inset -2px -2px #444444, inset 2px 2px #000000;
  margin-bottom: 60px;
}

.copyright {
  background: #1c1c1c;
  color: #e0e0e0;
  text-align: center;
  font-size: 13px;
  padding: 16px 12px;
  border: 1px solid #444444;
  border-radius: 4px;
  box-shadow: inset 0 0 0 1px #2c2c2c;
  font-family: "MS Sans Serif", "Segoe UI", "Arial", sans-serif;
  margin-top: 330px;
}

@media (max-width: 768px) {
  .page-frame {
    max-width: 95%;
    padding: 20px;
  }
}