:root {
  --primary-gradient: linear-gradient(135deg, #5b8cfa, #b36bff);
  --primary-color: #5b8cfa;
  --secondary-color: #b36bff;
  --text-color: #222;
  --background-color: #fff;
}

body {
  margin: 0;
  font-family: "Segoe UI", sans-serif;
  background-color: var(--background-color);
  color: var(--text-color);
  transition: background-color 0.3s ease, color 0.3s ease;
}

body.dark {
  --text-color: #ddd;
  --background-color: #121212;
}

.logo {
  height: 40px;
}

.container {
  max-width: 960px;
  margin: 0 auto;
  padding: 1rem;
}

.top-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.center {
  text-align: center;
}

h1 {
  font-size: 2.5rem;
  margin-bottom: 0.5rem;
}

.tagline {
  font-size: 1.2rem;
  color: #555;
  margin-bottom: 2rem;
}

.highlight {
  background: var(--primary-gradient);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  font-weight: bold;
}

.btn {
  display: inline-block;
  padding: 0.8em 1.6em;
  font-size: 1rem;
  font-weight: bold;
  color: white;
  background: var(--primary-gradient);
  border: none;
  border-radius: 999px;
  text-decoration: none;
  transition: all 0.3s ease;
  margin: 0.5rem;
}

.btn:hover {
  box-shadow: 0 0 10px rgba(91, 140, 250, 0.6), 0 0 10px rgba(179, 107, 255, 0.5);
  transform: translateY(-2px);
}

.btn.secondary {
  background: transparent;
  border: 2px solid var(--primary-color);
  color: var(--primary-color);
}

.btn.secondary:hover {
  background: var(--primary-gradient);
  color: white;
}

body.dark .btn.secondary {
  border-color: var(--secondary-color);
  color: var(--secondary-color);
}

.intro-image {
  margin-top: 3rem;
  text-align: center;
}

.intro-image img {
  max-width: 100%;
  height: auto;
  border-radius: 1rem;
  box-shadow: 0 0 16px rgba(0,0,0,0.1);
}

body.home {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
}

body.home .page-wrapper {
  flex: 1;
}

.footer {
  padding: 1rem 0;
  text-align: center;
  font-size: 0.9rem;
  color: #888;
}

/* 亮暗模式按钮，取消样式 */
#theme-toggle {
  background: none;
  border: none;
  padding: 0;
  cursor: pointer;
}

#light-icon, #dark-icon {
  width: 24px;
  height: 24px;
  display: inline-block;
  transition: opacity 0.3s ease;
}

#light-icon {
  display: inline;
}

body.dark #light-icon {
  display: none;
}

body.dark #dark-icon {
  display: inline;
}