Can't vertical center h1 inside div I'm having some troubles when trying to vertical center a header inside a div. CSS is the following:  .container {   background: #a3f;   padding-left: 3% !important; }  .container h4 {   vertical-align: middle;   text-align: center;   background: #f02; }   I have tried some  (also ), but the text continues at the top of the div.
How can I vertically center a "div" element for all browsers using CSS? I want to center a div vertically with CSS. I don't want tables or JavaScript, but only pure CSS. I found some solutions, but all of them are missing Internet Explorer 6 support. &lt;body&gt;     &lt;div&gt;Div to be aligned vertically&lt;/div&gt; &lt;/body&gt;  How can I center a div vertically in all major browsers, including Internet Explorer 6?
How can I make content disappear when a user logs in? I am working in Wordpress, and I would like to make certain elements disappear once a user logs in. How can I do this?  I have social icons on my page that I positioned to the center of my menu bar at the top of my website.  those icons are generated by a plugin  that is what i want to disappear How do I draw the graph of inequalities in the coordinate plane? I want to graph the following inequalities (done in desmos) in latex. I need the code. When is the present perfect tense used instead of the past tense?    I know that the present perfect tense is used when some adverbs (e.g., never, ever) are present in the sentence; the same is true for sentences like the following one.     When you returned, I have been at home since 3:00 PM.   In which other cases should I use the present perfect? Do the following sentences require it?     I have walked downtown everyday for a year.        I have been at home since 3:00 PM. Kali Linux: apt update returns "Hash Sum mismatch" error I'm experiencing exactly the same issue as described in this question: . Before you mark this as a duplicate however, I have tried the solutions posted there, as well as on numerous other sites, including:  sudo apt-get clean sudo rm -rf /var/lib/apt/lists/* sudo apt-get update   Editing /etc/apt/sources.list with alternate official mirrors, such as  deb http://mirrors.ocf.berkeley.edu/kali kali-rolling main non-free contrib or deb https://http.kali.org/kali kali-rolling main non-free contrib  Everything worked after I first imported the VM. I ran sudo apt update and it found some ~650 packages to upgrade. I ran sudo apt upgrade and it encountered an error partway through. That error was solved using sudo apt --fix-broken install, but that is when this hash sum error began. Unfortunately due to hours of troubleshooting I no longer have the details of the earlier error, but I believe it was an error extracting a package due to corrupt data.  I've tried multiple official mirrors, but I get the same error. Additionally, when I downloaded the Packages.gz file  on my Windows machine (VM host) and computed the SHA256 hash, I got the exact hash that apt printed as the expected value. This led me to believe that the error was not with the mirror but with my VM.  The next thing I tried was wget https://mirrors.ocf.berkeley.edu/kali/dists/kali-rolling/main/binary-amd64/Packages.gz followed by sha256sum Packages.gz, which provided yet another different hash output.  To be clear, I have seen 3 different hashes for the same file:   The "correct" hash shown by apt as expected, which is the one that windows also produced after downloading the file using a browser The incorrect hash calculated by apt, which led to the error A different hash calculated by sha256sum after downloading the file using wget using the same URL as for the browser download   I should also note that I have only been referencing the SHA256 hash in each step. The other hash functions are also mismatched when I run sudo apt update, but the file size is the same. I had considered that downloads might be failing due to limited disk space (it is a VM after all) but I don't think that's the case.  What am I missing? Equality in an integral estimate Let $u,v\in W^{1,p}(\Omega)$ with $1&lt;p&lt;\infty$ and $\Omega$ be a bounded smooth domain in $\mathbb{R}^N$. Suppose, we have $$\int_{\Omega}|\nabla u|^{p-2}\nabla u\nabla v\,dx=\left(\int_{\Omega}|\nabla u|^p\,dx\right)^\frac{p-1}{p}\left(\int_{\Omega}|\nabla v|^p\,dx\right)^\frac{1}{p} $$ Suppose the equality $$ \int_{\Omega}|\nabla u|^p\,dx=\int_{\Omega}|\nabla v|^p\,dx $$ holds. Then can we say that $u=v$ in $\Omega$? I tried in the following way: Since the first given equality, which is the equality in Holder's inequality holds, and by the second given equality holds, we have $|\nabla u|=|\nabla v|$ in $\Omega$. Then I am unable to proceed. Can someone please help to give an argument? Reflectivity of a glowing-hot metal surface When a polished piece of metal (or steel in particular) is heated to incandescence, how do its reflective properties change?  Given a mirror-like surface, would the object temporarily cease to act like a mirror at a certain temperature?  Would the specular reflection of light turn into diffuse reflection; in other words, would the surface temporarily become matte/dull?  I am not asking about permanent changes to the object such as melting, but rather can there be a temporary change in the reflectivity only while the the object is hot, that disappears when the object is cooled down?  Background of the question: I have a laser scanner that usually has trouble scanning shiny surfaces with high specular/ low diffuse reflectivity; and it seems to work a lot better for hot steel pieces than for cold ones. Glowing steel also looks less shiny to me than cold steel, but of course that is hard to tell with all the glowing Using something like this:  try:    # Something... except Exception as excep:    logger = logging.getLogger("component")    logger.warning("something raised an exception: " + excep)    logger.info("something raised an exception: " + excep)   I would rather not have it on the error-level cause in my special case it is not an error. java.lang.NullPointerException at org.glassfish.hk2.classmodel.reflect.impl.TypesImpl.getType Where to place log4j.xml How can you quickly get the complete path to a file for use in terminal? Looking for a Pre-1975, young adult, sci-fi, colored circle dimension crossing Looking for the title and or author of a long ago favorite; I have searched the web for it on and off for years.  I read a paperback novel about 40 years ago; it was probably a used book at that time. Probably pre-1975 publication.  In my memory it was written in the style of Andre Norton I have looked through her , but I am not finding it. It was a young adult sci-fi novel.  Plot; a young woman (gender was not strong, but I remember the main character being female) can see different colored circles floating around. When she looks at them just right, she can jump through to another universe.  In the other universe, things change.  She might become a lion, or maybe she is carrying a seed that becomes a net in the other universe.   Two bad guys are chasing her around the different dimensions, I recall one scene where they are all sliding down an icy slope and she jumps through a portal, to escape the bad guys.   There were a lot of complexities about, dimensions, what became what, different colors of portals and such. How do I get the form id of my form? I've just begun to make my modules and I'm at a standstill. I got this code from someone else and am trying to customize it:  function hook_form_alter(&amp;$form, &amp;$form_state, $form_id) {   if ($form_id == 'the form id for the node form') {     $form['#submit'][] = 'my_custom_submit_handler';   } } If $\sum_{n=1}^{\infty} a_n$ converges, then so does $\sum_{n=1}^{\infty} a_n^{\frac{n}{n+1}}$ Given a positive sequence $(a_n)$. Prove that if $\displaystyle \sum_{n=1}^{\infty} a_n$ converges, then so does $\displaystyle \sum_{n=1}^{\infty} a_n^{\frac{n}{n+1}}$.   I tried to use the root test, and I was stuck with the case $\lim \sup \sqrt[n]{a_n}=1$. Maybe we need some trick here.  Thanks so much. Should one downvote answers to off-topic questions? It annoys me when people post answers to obviously off-topic questions like , especially after those questions have already received several close votes. Migrations seem to happen rather infrequently these days, so there's probably no reputation to gain for questions that are likely to be closed. And although sure, the answer may help the OP, it also encourages bad behavior (posting off-topic questions.)  Is it appropriate to downvote these answers?   Personally, I think I could make a case for both sides. Dealing with questions of nefarious intent How should we treat questions that are, or have seeds of, evil or malicious purposes and actions, such as writing spambots and malware?    Should they be answered like regular "everybody keeps their pants on" questions? Or should there be some other type of response to this bad behaviour lot? Consider an irreducible but possibly periodic Markov chain on a finite state space with transition matrix $P$. We know there exists a unique stationary distribution $\pi$. If the Markov chain were aperiodic, we would have $P^n_{ij} \to \pi(j)$ as $n \to \infty$. This fails if the chain is periodic, but we have convergence of the Cesaro averages: $$\frac{1}{n}\sum_{k=1}^n P^k_{ij} \to \pi(j) \text{ as } n \to \infty.$$ Can anyone point me to a reference that states this fact? Every reference I've seen only considers convergence for aperiodic chains, or "fixes" periodicity by considering a lazy version of the chain. Alternatively, is there a simple way to obtain this result using the result for aperiodic chains? I have an URL structure like the following:     sitename.com/cellphone/nokia/galaxy-5678-nokia-cellphone-from-abc/   For more example:     sitename.com/cellphone/motorolla/new-motorolla-gta800-cellphone-from-zxy/   The directory structure is like the cellphone is the main directory of the module and the words like Motorolla and Nokia are subdirectories which are categories and then comes the title of the cellphone.  Here the word cellphone and Nokia in the first link and cellphone and Motorolla in the second link are repeated.  Is it any kind of keyword stuffing? will it be penalized by Google? How to install and use Ubuntu from a USB flash drive on Windows 8? Why does $\sum_1^\infty \frac1{n^3}=\frac52\sum_1^\infty\frac{(-1)^{n-1}}{n^3\binom{2n}{n}}$? Apery's original proof that $$ \zeta(3) \equiv \sum_1^\infty \frac1{n^3} $$ is irrational starts from an alternating series  $$ \zeta(3) = \frac52\sum_1^\infty\frac{(-1)^{n-1}}{n^3\binom{2n}{n}} $$  There must be a way to see that those two series are equal, but I have tried various telescoping and other techniques and I just can't see it. Help me out:       Show (preferably by reasonably elementary means) that$$\sum_1^\infty \frac1{n^3}=\frac52\sum_1^\infty\frac{(-1)^{n-1}}{n^3\binom{2n}{n}}$$ According to the , /opt is for "the installation of add-on application software packages".  /usr/local is "for use by the system administrator when installing software locally".  These use cases seem pretty similar.  Software not included with distributions usually is configured by default to install in either /usr/local or /opt with no particular rhyme or reason as to which they chose.  Is there some difference I'm missing, or do both do the same thing, but exist for historical reasons?