body {
    margin: 0;
    padding: 0;
    font-family: Arial, Helvetica, sans-serif;
    background: linear-gradient(135deg, #7b2ff7, #22a1f5); /* 紫蓝渐变背景 */
    color: #333;
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    align-items: center;
}

header {
    width: 100%;
    padding: 15px 40px;
    display: flex;
    justify-content: space-between; /* 左右分布 */
    align-items: center; /* 垂直居中 */
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(8px);
    box-shadow: 0 2px 8px rgba(0, 0, 0, 0.2);
    position: sticky; /* 滚动时固定 */
    top: 0;
    z-index: 1000;
}

.logo {
    font-size: 1.8rem;
    font-weight: bold;
    color: white;
    letter-spacing: 1px;
}

nav ul {
    list-style: none;
    display: flex;
    gap: 25px;
    margin: 0;
    padding: 0;
}

nav a {
    text-decoration: none;
    color: white;
    font-weight: 500;
    transition: color 0.3s;
}

nav a:hover {
    color: #ffd700;
}

main {
    max-width: 1000px;
    margin: 40px auto;
    padding: 20px;
    display: grid;    
    gap: 40px;        
}

section {
    background: white;
    padding: 20px;
    border-radius: 12px;
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
}

section h2 {
    margin-bottom: 10px;
    color: #333;
}

section p {
    margin-bottom: 15px;
    color: #555;
}

button {
    padding: 10px 16px;
    background: #6c63ff;
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    transition: 0.3s ease;
}

button:hover {
    background: #5148d8;
}

footer {
    width: 100%;
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 55px 30px;
    background: #333;
    color: white;
    font-size: 14px;
}

footer .footer-nav a {
    color: white;
    text-decoration: none;
    margin-left: 15px;
}

footer .footer-nav a:hover {
    text-decoration: underline;
}

@media (max-width: 600px) {
  header, footer {
    flex-direction: column;
    text-align: center;
  }

  nav {
    margin-top: 10px;
  }

  footer .footer-nav {
    margin-top: 8px;
  }
}