* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: "Microsoft YaHei", Arial, sans-serif;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 10px;
}

.login-container {
    width: 100%;
    max-width: 400px;
    padding: 20px;
}

.login-box {
    background: #fff;
    border-radius: 10px;
    padding: 40px;
    box-shadow: 0 10px 40px rgba(0,0,0,0.2);
}

.login-box h2 {
    text-align: center;
    color: #2c3e50;
    margin-bottom: 30px;
    font-size: 24px;
}

.form-group {
    margin-bottom: 20px;
}

.form-group label {
    display: block;
    margin-bottom: 8px;
    color: #555;
    font-weight: 500;
}

.form-group input[type="text"],
.form-group input[type="password"] {
    width: 100%;
    padding: 12px;
    border: 1px solid #ddd;
    border-radius: 5px;
    font-size: 14px;
    transition: border-color 0.3s;
}

.form-group input:focus {
    outline: none;
    border-color: #667eea;
}

.captcha-box {
    display: flex;
    gap: 10px;
    align-items: center;
}

.captcha-box input {
    flex: 1;
}

.captcha-box img {
    height: 40px;
    border: 1px solid #ddd;
    border-radius: 5px;
    cursor: pointer;
}

.btn-login {
    width: 100%;
    padding: 12px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: #fff;
    border: none;
    border-radius: 5px;
    font-size: 16px;
    cursor: pointer;
    transition: transform 0.2s;
}

.btn-login:hover {
    transform: translateY(-2px);
}

.btn-login:active {
    transform: translateY(0);
}

.login-tips {
    margin-top: 20px;
    text-align: center;
    color: #999;
    font-size: 12px;
}

/* 移动端优化 */
@media screen and (max-width: 768px) {
    body {
        padding: 5px;
    }
    
    .login-container {
        padding: 10px;
        max-width: 100%;
    }
    
    .login-box {
        padding: 25px 20px;
        border-radius: 8px;
    }
    
    .login-box h2 {
        font-size: 20px;
        margin-bottom: 25px;
    }
    
    .form-group {
        margin-bottom: 18px;
    }
    
    .form-group label {
        font-size: 14px;
        margin-bottom: 6px;
    }
    
    .form-group input[type="text"],
    .form-group input[type="password"] {
        padding: 14px 12px;
        font-size: 16px; /* 防止iOS自动缩放 */
    }
    
    .captcha-box {
        gap: 8px;
    }
    
    .captcha-box img {
        height: 46px;
        flex-shrink: 0;
    }
    
    .btn-login {
        padding: 14px;
        font-size: 16px;
    }
    
    .login-tips {
        font-size: 13px;
        margin-top: 15px;
    }
}

/* 小屏手机优化 */
@media screen and (max-width: 480px) {
    .login-box {
        padding: 20px 15px;
    }
    
    .login-box h2 {
        font-size: 18px;
        margin-bottom: 20px;
    }
    
    .form-group {
        margin-bottom: 15px;
    }
}

/* 横屏优化 */
@media screen and (max-width: 768px) and (orientation: landscape) {
    body {
        align-items: flex-start;
        padding-top: 20px;
    }
    
    .login-box {
        padding: 20px;
    }
    
    .login-box h2 {
        margin-bottom: 15px;
        font-size: 18px;
    }
    
    .form-group {
        margin-bottom: 12px;
    }
}

/* 触摸优化 */
@media (hover: none) and (pointer: coarse) {
    .btn-login,
    .captcha-box img {
        min-height: 44px;
    }
}