body{
    max-width: 720px;
    margin: 0 auto;
    padding: 24px 16px;
    font-family: system-ui, sans-serif;
    background: #f5f6fa;
    color: #1f2937;
}
a{
    color: #4f6ef7;
    text-decoration: none;
}
a:hover{
    text-decoration: underline;
}
h2, h3{
    margin: 16px 0 8px;
}
hr{
    border: none;
    border-top: 1px solid #e5e7eb;
    margin: 16px 0;
}
form{
    display: flex;
    flex-direction: column;
    gap: 10px;
    max-width: 320px;
    margin: 40px auto;
}
input{
    padding: 10px;
    border: 1px solid #ccc;
    border-radius: 6px;
    font: inherit;
}
input:focus{
    outline: 2px solid #4f6ef7;
    border-color: transparent;
}
label{
    display: flex;
    align-items: center;
    gap: 6px;
}
input[type="submit"]{
    background: #4f6ef7;
    color: #fff;
    border: none;
    cursor: pointer;
    font-weight: 600;
}
input[type="submit"]:hover{
    background: #3b5bdb;
}
.red_box{
    padding: 8px;
    background: #ff11002c;
    color: #b42318;
    border-radius: 6px;
}
.right_button{
    float: right;
}
body > a{
    display: inline-block;
    margin: 6px;
    padding: 10px 14px;
    background: #fff;
    border: 1px solid #e5e7eb;
    border-radius: 8px;
}