:root {
    --primary-blue: #4da6ff;
    --secondary-blue: #66b3ff;
    --accent-blue: #80c0ff;
    --light-blue: #445d75;
    --dark-blue: #0066cc;
    --text-light: #121d4f;
    --text-secondary: #395d7f;
    --glass-bg: rgba(225, 245, 255, 0.18);
    --glass-border: rgba(120, 200, 255, 0.25);
    --glass-shadow: rgba(0, 0, 0, 0.12);
    --transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}

/* 全局重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
  font-family: 'Segoe UI', -apple-system, BlinkMacSystemFont, sans-serif;
  color: var(--text-light);
  overflow-x: hidden;
  min-height: 100vh;
  position: relative;
  padding: 0;
  line-height: 1.6;
}

/* 背景粒子动画（保留） */
.bg-particle {
    position: fixed;
    top: 0;
    left: 0;
    width: 200%;
    height: 200%;
    background-image: 
        radial-gradient(circle at 10% 20%, rgba(77, 166, 255, 0.1) 0%, transparent 20%),
        radial-gradient(circle at 90% 30%, rgba(102, 179, 255, 0.1) 0%, transparent 15%),
        radial-gradient(circle at 50% 80%, rgba(128, 192, 255, 0.08) 0%, transparent 25%);
    pointer-events: none;
    z-index: -1;
    animation: particleFloat 40s infinite linear;
    transform: translateZ(0);
}

@keyframes particleFloat {
    0% { transform: translateY(0) rotate(0deg); }
    100% { transform: translateY(-50vh) rotate(360deg); }
}

/* 导航栏 - 玻璃头 */
.nav {
    width: 90vw;
    max-width: 1200px;
    margin: 5vw auto 2vw;
    padding: 1.5vw 2vw;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 70px;
    font-size: 28px;
    font-weight: 600;
    letter-spacing: 1px;
    color: var(--text-light);
    background: var(--glass-bg);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border: 1px solid var(--glass-border);
    border-radius: 16px;
    box-shadow: 0 8px 24px var(--glass-shadow);
    transition: var(--transition);
    cursor: pointer;
}

.nav h1 {
    margin: 0;
    font-size: 28px;
    letter-spacing: px;
    color: var(--text-light);
    position: relative;
    display: inline-block;
}

.nav h1::after {
    content: '';
    position: absolute;
    bottom: -5px;
    left: 0;
    width: 100%;
    height: 3px;
    background: linear-gradient(90deg, var(--primary-blue), var(--secondary-blue));
    border-radius: 2px;
    transform: scaleX(0);
    transition: transform 0.4s ease;
}

.nav:hover h1::after {
    transform: scaleX(1);
}

/* 底部信息区 */
.foot {
  width: 90vw;
  max-width: 1200px;
  margin: 20px auto 40px;
  padding: 15px;
  text-align: center;
  font-size: 13px;
  color: rgba(180, 220, 255, 0.7);
  letter-spacing: 0.5px;
  background: var(--glass-bg);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  border-radius: 16px;
  border: 1px solid var(--glass-border);
  box-shadow: 0 4px 12px var(--glass-shadow);
  line-height: 1.6; /* 行高增加适读性 */
}

.foot .foot-section {
  margin: 8px 0;
}

.foot span {
  color: var(--text-light);
}

.foot span:first-child {
  color: var(--light-blue);
  font-weight: 600;
}

.foot a {
    color: var(--dark-blue);
    text-decoration: none;
    position: relative;
    display: inline-block;
    transition: color 0.2s ease;
}

.foot a::after {
    content: '';
    position: absolute;
    left: 50%;
    bottom: 0;
    width: 0;
    height: 1px;
    background-color: var(--primary-blue);
    transform: translateX(-50%);
    transition: width 0.3s ease;
}

.foot a:hover::after {
    width: 100%;
}

/* 分割线 */
.foot .sep {
  margin: 12px 0;
  opacity: 0.3;
  font-weight: normal;
  font-size: 14px;
}

/* 响应式适配 */
@media (max-width: 768px) {
  .foot {
    padding: 12px;
    font-size: 12px;
  }
    .nav {
        height: 60px;
        font-size: 24px;
        padding: 10px;
    }
}

@media (max-width: 480px) {
  .foot {
    font-size: 11px;
  }

  .foot .sep {
    font-size: 12px;
    margin: 10px 0;
  }
    .nav {
        height: 50px;
        font-size: 22px;
    }
}