* {
    padding: 0;
    margin: 0; 
}
header {
     background-color: rgb(144, 147, 134);
     height: 69px;
     width: 100%;
}
header a{
    color: rgb(0, 0, 0);
    text-decoration: none;
}
header a:hover {
    text-decoration: underline;
}
header h1 {
    position: absolute;
    left: 3vw;
    line-height: 40px;
    background: url(/images/dollarlogo1.svg) no-repeat left center/contain;
    width: 525px;
    height: 200px;
    text-indent: -9999px;
    overflow: hidden;
    transform: translateY(calc(-50% + 33px));
}
header li {
    display: inline;
    padding: 0 1.2rem;
}
header ul {
        position: absolute;
        right: 5vw;
        top: 0;
        line-height: 69px;
}
.logo {
    background-color: rgba(255, 255, 255, 0.647);
    margin: auto;
    width: 100%;
    text-align: center;
    background-image: url(images/campus.png);
    background-size: cover; 
    background-position: center;
    background-repeat: no-repeat;
    background-color: rgba(46, 46, 46, 0.647);
    background-blend-mode: overlay;
}
.logo h1 {
    font-size: 200px;
}
.logo h2 {
    font-size: 170px;
}
.logo h3 {
    font-size: 140px;
}
.logo h4 {
    font-size: 110px;
}
.logo h4 {
    font-size: 80px;
}
.logo h5 {
    font-size: 50px;
}
.logo h6 {
    font-size: 20px;
}
/* 16:9 比例块 */
.ratio{position:relative;cursor:pointer;width:100%;height:0;padding-bottom:56.25%;}
.ratio iframe{
  position: absolute;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  border: 0;
}
/* ===== 视频展示区 ===== */
.video-showcase{
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 20px;
  padding: 30px 0;
}

/* 视口：只露 1 张卡片 */
.viewport{
  width: 80%;
  max-width: 900px;
  overflow: hidden;          /* 隐藏滚动条 */
  border-radius: 12px;
  box-shadow: 0 4px 20px rgba(0,0,0,.4);
}
.strip{
  display: flex;
  transition: transform .4s ease;
}
.card{
  flex: 0 0 100%;            /* 1 张卡片占满视口 */
}
/* 封面与图标 */
.cover{
  width: 100%;
  height: 100%;
  object-fit: cover;
  position: absolute;
  left: 0;
  top: 0;
}
.play-icon{position:absolute;left:50%;top:50%;transform:translate(-50%,-50%);width:60px;height:60px;border-radius:50%;background:rgba(0,0,0,.6);color:#fff;font-size:24px;display:flex;align-items:center;justify-content:center;transition:background .3s;}
.ratio:hover .play-icon{background:rgba(0,0,0,.8);}

/* 预览/正式播放器 */
.ratio iframe{position:absolute;left:0;top:0;width:100%;height:100%;border:0;}


/* ===== 左右箭头 ===== */
.arrow{
  width: 48px;
  height: 48px;
  border-radius: 50%;
  border: none;
  background: rgba(0,0,0,.6);
  color: #fff;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background .3s;
}
.arrow:hover{background: rgba(0,0,0,.8);}
.arrow svg{width: 60%;height: 60%;}
.slogan {
    text-align: center;
    margin: 30px auto 0;
    width: 100%;
}
.slogan h1{
    font-size: 35px;
}