* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    color: #333;
}

h1,
h2,
h3,
h4,
h5,
h6 {
    font-weight: 500;
}

ul {
    list-style: none;
}

a {
    text-decoration: none;
}

body {
    background: #f5f5f5;
    font-size: 1rem;
}

img {
    border-radius: 6px;
    width: 100%;
}

.container {
    width: 1000px;
    margin: 1vh auto;
    position: relative;
    min-height: 96vh;
    border-radius: 10px;
    display: flex;
    justify-content: space-between;
}

.catalogue {
    position: fixed;
    top: 7vh;
    left: 50%;
    transform: translateX(-290%);
    background: #fff;
    width: 280px;
    padding: 10px;
    border-radius: 10px;
    box-shadow: 0 5px 10px rgba(0, 0, 0, 0.1);
    min-height: 80vh;
    line-height: 2;
    z-index: 99;
    max-height: 90vh;
    overflow-y: scroll;
    opacity: 1;
}

.main {
    width: 100%;
    border-radius: 10px;
    background: #fff;
    padding: 10px;
    line-height: 2;
}



.level1 {
    text-indent: 2rem;
    font-size: 1rem;
}

.level2 {
    text-indent: 4rem;
    font-size: 0.8rem;
}

.main .level1 {
    text-indent: 0
}

.main .level2 {
    text-indent: 2rem
}

.fixedtoggle {
    position: fixed;
    opacity: 0;
    right: 1%;
    top: 65vh;
    width: 30px;
    height: 30px;
    border-radius: 50%;
    z-index: 99;
}

.sticky-header {
    position: sticky;
    top: 0;
    /* ⚠️ 必须指定，否则不生效 */
    z-index: 100;
    /* 防止被其他内容遮盖 */
    background: #fff;
    /* 建议设置背景色，避免内容透出 */
    width: 100%;
    border-bottom: 1px solid #eaeaea;
}



.header {
    width: 1000px;
    margin: 0 auto;
    display: flex;
    justify-content: space-between;
    align-items: center;
}


.nav a{
    font-size: 1.1rem;
      color: #333;
      padding:0 10px;

}

.nav a.cur {
    color: #fa5c00;
}

.logo {
    width: 50px;
    height: 50px;
}


@media screen and (max-width: 1000px) {
    .container {
        width: 100%;
        margin: 0;
    }

    img {
        border-radius: 6px;
        width: 100%;
    }

    .header {
        width: 100%;
    }

    .nav a {
        line-height: 60px;
        font-size: 0.9rem;
        padding: 0 1%;
        display: inline-block;
    }

    .nav {
        width: calc(100% - 60px);
    }

    .catalogue {
        position: fixed;
        top: 70vh;
        left: 5%;
        transform: translateX(0%);
        background: #fff;
        width: 90%;
        padding: 10px;
        max-height: 30vh;
        min-height: 20vh;
        overflow-y: scroll;
        opacity: 0;
    }

    .fixedtoggle {
        opacity: 1;
    }

}