html,
body {
    margin: 0;
    padding: 0;
    width: 100%;
    height: 100%;
    overflow: hidden;
}
ul,
ol {
    margin: 0;
    padding: 0;
}
ol {
    padding-left: 1.5em;
}
ul > li {
    list-style: none;
}
h2 {
    margin-top: 0;
    margin-bottom: 16px;
    font-weight: 500;
    font-size: 22px;
}
h4 {
    margin: 10px 0;
    font-weight: 400;
}
p {
    margin: 8px 0;
}
img {
    margin-top: 4px;
    margin-bottom: 8px;
}

.ad {
    width: 728px;
    height: 90px;
}
.install {
    margin-top: 10px;
    padding-left: 20px;
    height: calc(100% - 100px);
    color: rgb(31, 35, 41);
}
.title {
    padding-left: 8px;
    font-size: 34px;
    line-height: 48px;
    height: 48px;
}
.main {
    display: flex;
    height: calc(100% - 48px);
}
.nav-bar {
    width: 260px;
    flex-shrink: 0;
    position: relative;
    transition: all 0.2s;
}
.expand-btn {
    cursor: pointer;
    margin: 0;
    margin-left: 12px;
    margin-top: 21px;
}
.expand-box.nav-bar {
    width: 30px;
}
.expand-box .nav-item {
    width: 0;
    padding: 0;
}

.nav-item {
    margin: 6px;
    padding: 6px;
    cursor: pointer;
    color: #888;
    white-space: nowrap;
    overflow: hidden;
}
@media screen and (max-width: 720px) {
    .title {
        font-size: 30px;
    }
    h2 {
        margin-left: 8px;
    }
    .install {
        padding-left: 8px;
    }
    .expand-btn {
        margin-left: 8px;
    }
    .nav-bar {
        width: 30px;
        position: absolute;
        left: 0px;
    }
    .nav-item {
        width: 0;
        padding: 0;
    }
    .expand-box.nav-bar {
        width: 260px;
        background: rgba(246, 246, 246, 0.8);
        backdrop-filter: blur(10px);
        border-radius: 4px;
        box-shadow: 0 2px 12px 0 #00000026;
    }
    .expand-box .nav-item {
        width: auto;
        padding: 6px;
    }
}
.nav-item.active {
    color: rgb(51, 112, 255);
}
.nav-content-box {
    margin-top: 16px;
    height: calc(100% - 16px);
    overflow: scroll;
    scroll-behavior: smooth;
    flex-grow: 1;
}
.nav-content {
    margin: auto;
    max-width: 1000px;
    padding: 0 20px;
    word-break: break-all;
}
.content-item {
    margin-bottom: 30px;
}
.content-item img {
    max-width: 100%;
}
.btn-text {
    background-color: rgba(186, 206, 253, 0.7);
}
.attach {
    margin-left: -1em;
}