/* --- 变量定义与全局重置 --- */
:root {
  --bg-primary: #0a0a0f;
  --bg-secondary: #12121a;
  --bg-card: rgba(255, 255, 255, 0.05);
  --accent-color: #ff2a55; /* 红桃经典红 */
  --accent-hover: #e01e45;
  --text-main: #ffffff;
  --text-muted: #a0a0b0;
  --border-color: rgba(255, 255, 255, 0.1);
  --max-width: 1200px;
}

* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
  background-color: var(--bg-primary);
  color: var(--text-main);
  line-height: 1.6;
  overflow-x: hidden;
}

/* --- 统一导航栏 --- */
.header {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  background: rgba(10, 10, 15, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border-color);
  z-index: 1000;
}

.nav-container {
  max-width: var(--max-width);
  margin: 0 auto;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1rem 1.5rem;
}

.logo {
  display: flex;
  align-items: center;
  gap: 0.5rem;
  font-size: 1.5rem;
  font-weight: 800;
  color: var(--text-main);
  text-decoration: none;
}

.logo span {
  color: var(--accent-color);
}

.nav-links {
  display: flex;
  gap: 2rem;
  list-style: none;
}

.nav-links a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.95rem;
  transition: color 0.3s;
}

.nav-links a:hover,
.nav-links a.active {
  color: var(--accent-color);
}

.btn-primary {
  background: linear-gradient(135deg, #ff2a55, #e01e45);
  color: #fff;
  padding: 0.65rem 1.5rem;
  border-radius: 30px;
  text-decoration: none;
  font-weight: 600;
  box-shadow: 0 4px 15px rgba(255, 42, 85, 0.4);
  transition: all 0.3s ease;
  display: inline-block;
  text-align: center;
}

.btn-primary:hover {
  transform: translateY(-2px);
  box-shadow: 0 6px 20px rgba(255, 42, 85, 0.6);
}

/* --- 内容通用布局 --- */
.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 120px 1.5rem 60px;
  min-height: calc(100vh - 180px);
}

.page-title {
  text-align: center;
  font-size: 2.5rem;
  margin-bottom: 1rem;
}

.page-subtitle {
  text-align: center;
  color: var(--text-muted);
  margin-bottom: 3rem;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 2rem;
}

.card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  padding: 2rem;
  border-radius: 16px;
  backdrop-filter: blur(10px);
  transition: transform 0.3s, border-color 0.3s;
}

.card:hover {
  transform: translateY(-5px);
  border-color: var(--accent-color);
}

/* --- 统一页脚 --- */
.footer {
  background: var(--bg-secondary);
  border-top: 1px solid var(--border-color);
  padding: 3rem 1.5rem 1.5rem;
  margin-top: 4rem;
}

.footer-container {
  max-width: var(--max-width);
  margin: 0 auto;
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
  gap: 2rem;
  margin-bottom: 2rem;
}

.footer-col h4 {
  margin-bottom: 1rem;
  color: var(--text-main);
}

.footer-col ul {
  list-style: none;
}

.footer-col ul li {
  margin-bottom: 0.5rem;
}

.footer-col a {
  color: var(--text-muted);
  text-decoration: none;
  font-size: 0.9rem;
}

.footer-col a:hover {
  color: var(--accent-color);
}

.footer-bottom {
  text-align: center;
  color: var(--text-muted);
  font-size: 0.85rem;
  border-top: 1px solid var(--border-color);
  padding-top: 1.5rem;
}

/* --- 移动端响应式适配 --- */
@media (max-width: 768px) {
  .nav-links {
    display: none;
  }
  .page-title {
    font-size: 1.8rem;
  }
}