*{
    margin:0;
    padding:0;
    box-sizing:border-box;
}
body{
    font-family:'Segoe UI','Noto Sans CJK SC','system-ui', -apple-system, sans-serif;
    background-image: url('/static/国旗.svg');
    background-repeat:no-repeat;
    background-size:cover;
    background-position:center;
    min-height:100vh;
}
.container{
    max-width:500px;
    margin:0 auto;
    border-radius:25px;
    background:rgba(255,255,255,0.9);
    box-shadow:0 17px 30px rgba(0,0,0,0.2);
}
.header{
    text-align:center;
    margin-bottom:30px;
}
.header h1{
    color:#333;
    font-size:45px;
}
.navbar{
    background:rgba(255,255,255,0.9);
    box-shadow:0 2px 10px rgba(0,0,0,0.1);
    padding:15px 30px;
    display:flex;
    justify-content:space-between;
    align-items:center;
    flex-wrap:wrap;
    gap:15px;
    margin-bottom:30px;
    border-radius:12px;
}

.nav-links{
    display:flex;
    gap: 20px;
    align-items:center;
    flex-wrap:wrap;
}
.nav-links a{
    color: #83acf1;
    text-decoration: none;
    margin: 0 5px;
    font-weight: 500;
    transition: all 0.3s ease;
}
.nav-links a:hover{
    color: #7799d4;
    text-decoration: underline;
}
.form-group{
    margin-bottom:20px;
}
.form-group label{
    display:block;
    margin-bottom:8px;
    font-weight:600;
    color:#555;
}
.form-group input{
    width:60%;
    padding:12px 15px;
    border:1px solid #ddd;
    border-radius:8px;
    font-size:16px;
    transition:0.2s;
}
.form-group input:focus{
    outline:none;
    border-color:#667eea;
    box-shadow:0 0 0  3px rgba(102,126,234,0.1);
}
.btn{
    display: inline-block;
    width:7%;
    padding:12px;
    background:#667eea;
    color:white;
    border:none;
    border-radius:8px;
    font-size:16px;
    font-weight:600;
    cursor:pointer;
    transition:0.2s;
    text-align:center;
    text-decoration:none;
}
.btn:hover{
    background:#5a67d8;
    transform:translateY(-2px);
}
.flash{
    padding:12px 15px;
    border-radius:8px;
    margin-bottom:20px;
    background:#e2e3e5;
    color:#383d41;
    border-left:4px solid #6c757d;
}
.flash.success{
    background:#d4edda;
    color:#155724;
    border-left-color:#28a745;
}
.flash.error{
    background:#f8d7da;
    color:#155724;
    border-left-color:#dc3545;
}
a{
    color:#667eea;
    text-decoration:none;
}
a:hover{
    text-decoration:underline;
}
@media(max-width:600px){
    .container{
        padding:20px 15px;
    }
    .navbar{
        flex-direction:column;
        text-align:center;
    }
    .nav-links{
        justify-content:center;
    }
}