* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}
body {
    background-color: #667eea;
    background-image: url('/media/lithium/login/logins.jpg');
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    background-attachment: fixed;
    font-family: 'Segoe UI', 'Roboto', 'PingFang SC', 'Microsoft YaHei', sans-serif;
    height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0;
    padding: 20px;
    position: relative;
}
body::before {
    content: '';
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.45);
    z-index: 0;
    pointer-events: none;
}
.login-container {
    width: 500px;
    max-width: 92%;
    background: #ffffff;
    border-radius: 24px;
    box-shadow: 0 30px 60px rgba(0, 0, 0, 0.4);
    overflow: hidden;
    z-index: 2;
    position: relative;
}
.login-header {
    background: linear-gradient(135deg, #1f2c3e, #2c3e50, #3a5670);
    color: white;
    padding: 38px 20px;
    text-align: center;
}
.login-header h2 {
    margin: 0;
    font-weight: 500;
    font-size: 28px;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
}
.login-body {
    padding: 48px 42px;
    background: #fff;
}
.form-group {
    margin-bottom: 28px;
}
.form-control {
    width: 100%;
    padding: 16px 20px;
    border: 1px solid #e0e4e8;
    border-radius: 14px;
    font-size: 16px;
    transition: all 0.25s ease;
    background-color: #fefefe;
}
.form-control:focus {
    border-color: #3498db;
    outline: none;
    box-shadow: 0 0 0 4px rgba(52, 152, 219, 0.15);
}
.captcha-group {
    display: flex;
    gap: 16px;
    align-items: center;
}
.captcha-img {
    height: 56px;
    width: 130px;
    object-fit: cover;
    border: 1px solid #e2e8f0;
    border-radius: 14px;
    cursor: pointer;
    transition: all 0.2s;
    background: #f1f5f9;
    flex-shrink: 0;
}
.captcha-img:hover {
    transform: scale(1.02);
    border-color: #3498db;
}
.btn-login {
    width: 100%;
    padding: 16px 20px;
    background: linear-gradient(105deg, #2c6e9e, #1e4668);
    color: white;
    border: none;
    border-radius: 40px;
    font-size: 18px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.25s;
    letter-spacing: 1.5px;
    box-shadow: 0 6px 14px rgba(28, 78, 128, 0.3);
    display: flex;
    justify-content: center;
    align-items: center;
    gap: 8px;
}
.btn-login:hover {
    background: linear-gradient(105deg, #1f557c, #123a57);
    transform: translateY(-2px);
    box-shadow: 0 12px 22px rgba(28, 78, 128, 0.4);
}
.btn-login:active {
    transform: translateY(1px);
}
.form-footer {
    text-align: center;
    margin-top: 34px;
    font-size: 13px;
    color: #7f8c8d;
    padding-top: 20px;
    border-top: 1px solid #ecf0f1;
}
@media (max-width: 640px) {
    .login-body {
        padding: 32px 24px;
    }
    .login-header h2 {
        font-size: 24px;
    }
    .form-control {
        padding: 14px 18px;
        font-size: 15px;
    }
}