Center text within a div I am having difficulty trying to center my navigation text on my page. I want all my links to be in the center of my page the whole time, even if I re-size my window. Thanks for your time.  HTML:  &lt;div id="navcont"&gt;      &lt;div id="navigation"&gt;         &lt;ul&gt;             &lt;li class="home"&gt;&lt;a href="#home"&gt;Home&lt;/a&gt;&lt;/li&gt;             &lt;li class="about"&gt;&lt;a href="#about"&gt;About me&lt;/a&gt;&lt;/li&gt;             &lt;li class="portfolio"&gt;&lt;a href="#portfolio"&gt;Portfolio&lt;/a&gt;&lt;/li&gt;             &lt;li class="contact"&gt;&lt;a href="#talktome"&gt;Talk to me&lt;/a&gt;&lt;/li&gt;         &lt;/ul&gt; &lt;/div&gt; &lt;/div&gt;   CSS:  #navcont{     height: 80px;     background-color: #ebebeb;     width: 100%;     padding-top: 10px; } #navigation{     font-size: 15px;     font-family: "TYPOGRAPH PRO" arial; } #navigation ul li{     list-style:none;     display:inline-block;     background-color:red;     width:120px; } #navigation ul li a{     text-transform:uppercase;     text-decoration:none;     color:black; } #navigation ul li a:hover{     color:#217c7e; }
How to horizontally center an element How can I horizontally center a &lt;div&gt; within another &lt;div&gt; using CSS? &lt;div id=&quot;outer&quot;&gt;   &lt;div id=&quot;inner&quot;&gt;Foo foo&lt;/div&gt; &lt;/div&gt;
Why is the camera tilting around the z axis when I only specified x and y? My goal is to program a camera to point towards the mouse cursor. I attached the following script to the Main Camera.   using UnityEngine; using System.Collections;  public class CameraController : MonoBehaviour {      public float sensitivity;      // Update is called once per frame     void Update () {         transform.Rotate (Input.GetAxis ("Mouse Y") * -1 * sensitivity, Input.GetAxis ("Mouse X") * sensitivity, 0);     } }   I "told" the camera to rotate around the x and y axes. Whenever it does this, the camera tilts sideways. When I checked the rotation of Main Camera, I saw that the z rotation had changed. Why is it rotating around the z axis when I left it at 0? Why is pruning not needed for random forest trees? Breiman says that the trees are grown with out pruning. Why? I mean to say that there must be a solid reason why the trees in random forest are not pruned. On the other hand it is considered very important to prune a single decision tree to avoid over fitting. Is there some literature available to read for this reason? Of course the trees may not be correlated but there still will be a possibility of over fitting. Why can't the Klein-Gordon equation with a Couloumb potential describe the hydrogen atom?  Why can the first order Dirac equation explain it? What are the failures? Is there a sandbox to post test questions? I have noticed a behaviour that may or may not be a  bug. It is a discrepancy between the preview and the rendered result, which is why I would need to post a question to check it out.  Is there an official place to do that? How do I make a floor plan with specific dimensions? This is my very first time of using blender. I've tried several tutorials but can't find anything that tells me how to do the very basic thing i want to do.  I simply want to draw a floor plan for a room which is 13 feet by 11 feet and make it 3d so that ultimately i can play with where things go in that room.  Can anyone take me through the steps needed to do this?   I will be so grateful.  Thank you in advance What I want to show is the following statement.  For every prime of the form $2^{4n}+1$, 7 is a primitive root.  What I get is that  $$7^{2^{k}}\equiv1\pmod{p}$$ $$7^{2^{k-1}}\equiv-1\equiv2^{4n}\pmod{p}$$ $$7^{2^{k-2}}\equiv(2^{n})^2\pmod{p}$$ Thus $(\frac{2^n}{p})=(\frac{7^{2^{k-2}}}{p})=1$.  I think that $7$ is important because $7$ is a primitive root but I don't know how to use $7$. Strange arrow mark with TikZ edge and anchors. When I draw an edge between two nodes with anchors and globally set option [-&gt;], I get an additional arrow tip symbol at the beginning of the last edge in the path. For example in  \documentclass{article} \usepackage{tikz}  \begin{document} \begin{tikzpicture}     \node (A) at (0,0) {$A$};     \node (B) at (1,0) {$B$};      \draw[-&gt;] (A.north east) edge (B.north west);      \draw (A.south east) edge[-&gt;] (B.south west); \end{tikzpicture} \end{document}   the first \draw command produces incorrect output, while the second produces correct output:    Am I doing something wrong, or is this a bug in TikZ? Video lectures on graduate level Classical Electrodynamics This is a rather broad question. Does anyone know of good video lectures for graduate level classical electrodynamics? On the nature of the collapse of the wave function The collapse of the wave function by measurements is one of the most mysterious properties of quantum mechanics.    At what scale does the wave function collapse? What are the conditions for a collapse?  Can it be made precise?  Does the collapse happen instantaneously, or is it spread out in time?  What is the precise equation for the collapse?  Why is the collapse time-asymmetric, and can this explain the arrow of time? What is difference between: "I have been married with (was married with, married) her for three years." What is the difference between the three sentences below?   I have been married with her for three years. I was married with her for three years. I married her for three years. Some Git commands take commit ranges and one valid syntax is to separate two commit names with two dots .., and another syntax uses three dots ....  What are the differences between the two? How to mount read-write an ext4 partition on Windows? I want to use ext4 on my external HDD, but it must be cross-platform. (At least Linux, Win7 &amp; WinXP).  Unfortunately, I haven't found any proper driver allowing Windows to WRITE to ext4. I've found , but it only reads ext4.     9. ext4 extent read-only, no  size truncating and expanding support   More:     Supported Ext3/4 features:         flexible inode size: > 128 bytes, up to block size   dir_index:    htree directory index   filetype:     extra file mode in dentry   large_file:   > 4G files supported   sparse_super: super block backup in group descriptor   uninit_bg:    fast fsck and group checksum   extent:       reading, writing with no extending.   journal:      only support replay for internal journal         Unsupported Ext3/4 features:         journal: log-based operations, external journal   extent: size truncating &amp; expanding, file deletion   flex_bg: first metadata group   EA (extended attributes), ACL support      Also, I have found a patch for Ext4Fsd v0.50 ():     New: Matt Wu has made a new release 0.50 at   ext2fsd.com.  Support for ext4 extents and fix   for BSOD on Windows 7.   I don't think it will be safe. Also I've read some words about writing ext4 in Windows could cause data loss on the disk...  What is the External HDD used for? - First, it will store backups, then family movies, pictures. Some music, and etc. It will be connected to a Raspberry Pi, if I finally receive it. It won't really move, just when it is used to migrate computer's data to a new one. The largest files it will store are Clonezilla disk images (I don't know, if they will be large files or not).  Can someone provide a solution for this problem? Or is there NO important enough difference between ext4 and ext3, and I should use ext3? - (If yes, then can I use Ext2Fsd for that ext3 mount?)  Thank you! Abelian group (Commutative group) Prove that if in a group $(ab)^2= a^2 b^2$ then the group is commutative.  I am having a hard time doing this. Here is what I have so far: Proof:  $a^2 b^2= a^1 a^1 b^1 b^1$ =$aa^{-1}bb$ =ebb Hence,$aa^{-1}=e$  I am stuck, I do not know if this is the right process in proving this tcpdump : lost packets Can I visit other Schengen countries on a long-term Schengen visa or residency permit? I have the following question:    $\textbf{Question}:$ Let $\mathcal{F}_1$ and $\mathcal{F}_2$ be two algebras. Is $\mathcal{F}_1 \cap \mathcal{F}_2$ a $\sigma$-algebra?  I believe the answer is no. I know the definition of an algebra and the definition of $\sigma$-algebra.    I'm assuming I need to show that the intersection of the finite unions of each algebra is finite, but then I get stuck trying to work out how to show it is not a $\sigma$-algebra.  All help is appreciated.  Many thanks, John How to plot the first n rows of a table using pgfplots? Pass by Reference / Value in C++ I would like to clarify the differences between by value and by reference.  I drew a picture     So, for passing by value,  a copy of an identical object is created with a different reference, and the local variable is assigned the new reference, so to point to the new copy  How to understand the words: " If the function modifies that value, the modifications appear also within the scope of the calling function for both passing by value and by reference "  Thanks! Launch Debian and Windows Understanding relation between Quotient Space and $S^1$ There is this example at the Wikipedia article on Quotient spaces (QS):     Consider the set $X = \mathbb{R}$ of all real numbers with the ordinary topology, and write $x \sim y$ if and only if $x−y$ is an integer. Then the quotient space $X/\sim$ is homeomorphic to the unit circle $S^1$ via the homeomorphism which sends the equivalence class of $x$ to $\exp(2πix)$.   I understand relations, equivalence relation and equivalence class but quotient space is still too abstract for me. This seems like a simple enough example to begin with.  I understand (sort of) the definition but I can't visualize. And by this example and others, there is a lot of visualizing going on here! torus, circles etc.