body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    margin: 0;
    color: #111;
    background: #fff;
}

header {
    display: flex;
    justify-content: space-between;
    padding: 20px 40px;
    border-bottom: 1px solid #eee;
}

/* 关键修改：大幅减小上下内边距 */
.hero {
    text-align: center;
    padding: 48px 20px;   /* 原 120px → 48px，保持呼吸感但更紧凑 */
}

.hero h2 {
    font-size: 48px;
    font-weight: 600;
    margin-bottom: 8px;   /* 新增：与副标题的间距，原无定义可能塌陷或过远 */
}

.grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 40px;
    padding: 80px;
}