* {
    margin: 0;
    padding: 0;
    list-style: none;
    text-decoration: none;
    box-sizing: border-box;
  }
  
  img {
    width: 100%;
    height: auto;
    vertical-align: bottom;
  }
  
  body {
    font-family: 'Arial', sans-serif;
    line-height: 1.6;
    color: #333;
    height: 100%;
  }
  
  #wrap {
    display: flex;
    flex-direction: column;
    min-height: 100vh;
  }
  
  
  /* header */
  header {
    /* background: #EEE; */
    position: relative;
  }
  
  header h1 {
    /* text-align: center; */
    padding: 1rem;
    position: absolute;
    top: 0;
    left: 1rem;
  }
  
  nav {
    position: absolute;
    top: 2rem;
    right: 1rem;
  }
  
  nav ul {
    list-style: none;
    padding-bottom: 1rem;
    text-align: center;
  }
  
  nav ul li {
    display: inline-block;
    margin: 0 10px;
  }
  
  nav ul li a {
    font-weight: bold;
    color: #333;
  }
  
  .sticky {
    position: sticky;
    top: 0;
    width: 100%;
    z-index: 1000;
  }
  
  /* main contents */
  main {
    padding: 1rem;
    margin: 0 auto;
    max-width: 1200px;
    flex-grow: 1;
  }
  
  section {
    padding: 20px;
    background: #FFF;
  }
  
  .container{
    display: flex;
    gap: 20px;
  }
  
  .column-img {
    flex: 1;
  }
  
  .column-text {
    flex: 2;
  }
  
  /* footer */
  footer {
    background: #333;
    color: #fff;
    text-align: center;
    padding: 1rem;
    width: 100%;
  }
  
  a.pagetop {
    display: block;
    width: 50px;
    height: 50px;
    text-align: center;
    box-sizing: border-box;
    padding-top: 12px;
    border-top-left-radius: 10px;
    border-top-right-radius: 10px;
    background-color: #666;
    color: #FFF;
    position: fixed;
    bottom: 0;
    right: 20px;
  }
  
  html {
    scroll-behavior: smooth;
  }