html, body {
    height: 100%;
}

body {
    overflow-x: hidden;
    color: #000000d9;
    font-size: 14px;
    font-family: Avenir,-apple-system,BlinkMacSystemFont,Segoe UI,Roboto,Helvetica Neue,Arial,Noto Sans,sans-serif,apple color emoji,segoe ui emoji,Segoe UI Symbol,noto color emoji,sans-serif;
    background: #fff;
    transition: background 1s cubic-bezier(.075,.82,.165,1);
}
h1 {
    margin-top: 8px;
    margin-bottom: 20px;
    font-size: 42px;
    font-weight: 500;
    line-height: 38px;
}

h2 {
    font-weight: 500;
}

h1,h2,h3,h4 {
    color: #000000d9;
}

header {
    position: relative;
    z-index: 10;
    max-width: 100%;
    background: #fff;
    box-shadow: 0 2px 8px #f0f1f2;
    flex-flow: nowrap;
    height: 64px;
    row-gap: 0px;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

header .logo {
    width: 130px;
}

header ul {
    list-style: none;
}

header ul li {
    display: inline-block;
    min-width: 64px;
    height: 64px;
    padding-right: 12px;
    padding-left: 12px;
    line-height: 64px;
    position: relative;
}

header ul li.selected a, header ul li a:hover {
    color: #1890ff;
}
header ul li.selected::after, header ul li a:hover::after {
    border-bottom: 2px solid #1890ff;
    content: '';
    top: 0;
    right: 12px;
    bottom: auto;
    left: 12px;
    border-width: 2px;
    position: absolute;
    transition: border-color 0.3s cubic-bezier(0.645, 0.045, 0.355, 1);
}

header ul li a {
    color: #000000d9;
    transition: color .3s ease;
    touch-action: manipulation;
    text-decoration: none;
    background-color: transparent;
    outline: none;
    cursor: pointer;
}

main {
    text-align: center;
    display: flex;
    align-items: center;
    justify-content: center;
    height: 80%;
}

.btn {
    line-height: 1.5715;
    position: relative;
    display: inline-block;
    font-weight: 400;
    white-space: nowrap;
    text-align: center;
    background-image: none;
    border: 1px solid transparent;
    box-shadow: 0 2px #00000004;
    cursor: pointer;
    transition: all .3s cubic-bezier(.645,.045,.355,1);
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
    touch-action: manipulation;
    height: 32px;
    padding: 4px 15px;
    font-size: 14px;
    border-radius: 2px;
    color: #000000d9;
    border-color: #d9d9d9;
    background: #fff;
}

.btn:hover, .btn:focus {
    text-decoration: none;
    background: #fff;
    text-decoration: none;
    color: #40a9ff;;
    border-color: #40a9ff;
    background: #fff;
}

.btn-primary:hover, .btn-primary:focus {
    color: #fff;
    border-color: #40a9ff;
    background: #40a9ff;
}

.btn-primary {
    color: #fff;
    border-color: #1890ff;
    background: #1890ff;
    text-shadow: 0 -1px 0 rgb(0 0 0 / 12%);
    box-shadow: 0 2px #0000000b;
}