OpenLLM-France/wikimedia huggingface dataset:
# Cascading Style Sheets/CSS Menus

Use
to emulate floating and create bookends for a masthead without encountering the side effects of floats
Use absolutely positioned divs nested in a relatively positioned wrapper to create equal height columns using the following steps:
- Create the columns using floats or inline-block
- Create a wrapper div around all the columns and set it to be relatively positioned
- Place an absolutely positioned div as the last element inside the wrapper div
- Set the absolutely positioned div to { bottom:0; height: 100%; z-index: -1; }
- Set the height to a fixed number large enough to fill the columns for IE6
- Set the width of the absolutely positioned div equal to the width of the first column
- Set the left offset of the absolutely positioned div so that it overlaps the first column
- Set the desired border and background color of the absolutely positioned div
- Repeat this step for the remaining columns if necessary
- Set { position:relative; z-index:2; }, add vertical padding(or replace margins with padding) and reset the background on any containers above or below the columns to hide the overflow in IE6
- Set { top:1px; margin-top: -1px; } to vertically align the absolutely positioned div in IE6
- Set clip:rect(0 ## 9999px 0); where ## is the width of the column to truncate horizontal overflow in IE6
- If z-index:2 fails in IE6, make it higher than the z-index of the wrapper div if they are in the same parent
- If z-index:2 still fails in IE6, make it higher than the z-index of the wrapper div's parent
Use nested spans to created irregularly shaped anchors without image maps with the following steps: - Use the same setup as above to nest spans within anchors
- Set the anchors and the spans to be absolutely positioned
- Set the ul to be relatively positioned
- Set a single background image for both the anchors and spans
- Reposition the anchors and spans so that the bounding boxes for the anchors do not overlap
- Change the background position of the anchors and spans on :hover to match the rollover state
# Cascading Style Sheets/Background
## Background properties

There are five properties that control the background of an element:

### background-color W3C Specification CSS1 CSS2.1

    sets the background color, this will be seen if no background image is specified or the image does not cover the entire element. It will also show through any transparent areas in the image. The color may be set to any CSS color or the keyword transparent.

### background-image W3C Specification CSS1 CSS2.1

    the image to use as a background.

### background-repeat W3C Specification CSS1 CSS2.1

    controls the tiling of the background image (possible values: repeat | repeat-x | repeat-y | no-repeat | inherit)

### background-attachment W3C Specification CSS1 CSS2.1

    does the background scroll with the page (the default) or is it fixed within the viewport?

### background-position W3C Specification CSS1 CSS2.1

    places the image relative to the element's bounding box.
You should consider supplying a background color as well as a background image in case the user has disabled images.
Examples:

### Shorthand property

W3C Specification CSS1 CSS2.1
The background shorthand property can be used to set all five individual background properties in a single declaration, e.g.
is equivalent to the previous example.
Note that if some values are omitted from the background property the individual properties for the missing values are set to their initial values. This is important to remember if more than one rule is setting the background properties on an element. For example
is equivalent to

## Advanced Opacity

Opacity is a block level property that effects all the children. To use colors with alpha channels, see RGBA and HSLA.
Opacity in the background property is still a new concept and is not compliant across all web browsers however here is a tiny bit about this function
filter: alpha(opacity=40); -moz-opacity:.40; opacity:.40;
adding the alpha(opacity=40) will add a 40% alpha transparency however as mentioned this still does not work on all browsers, for this to work on Firefox for example the -moz hack has to be used . So -moz-opacity:.40 will obviously do the same thing but this code is only relevant for Firefox users.
transparency W3C Specification CSS3

## External links

A nice demonstration of the effects that can be achieved with backgrounds on css/edge
A nice tutorial on the use of opacity in the background.
# Cascading Style Sheets/Clipping
## Clip Property Top/Left Coordinates

The top and left parameters of the clip property remove any pixels with coordinates above or before the specified values, based on the top and left edges of the element.

## Clip Property Bottom/Right Coordinates

* The bottom and right parameters remove any pixels located below or after the specified values, based on the top and left edges of the element.
* The values for bottom and right must be higher than the values of top and left in order to see any of the layer.

## Clip Property Limitations

* The clipped element must be absolutely positioned for the clip property to work, so use a relatively positioned container around it.
* Specifying the height of the container keeps the next line from overlapping with the clipped areas.

## Clip Property Usage

Use clip: rect(0, auto, auto, 0); as the default clip values to do proper trial and error
Use clip: rect(0, ###, auto, 0); to clip from left-to-right
Use clip: rect(0, auto, ###, 0); to clip from top-to-bottom

## Using the Clip Property to create a File Upload Button Replacement Solution

Use clipping, opacity and z-index to style file inputs by transparently positioning the field over an image:
Use separate styles for Webkit browsers since the file input is rendered differently:
# Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nc6/3. Bb5/3...f5/4. Nc3/4...fxe4/5. Nxe4/5...d5/6. Nxe5/6...dxe4/7. Nxc6

| | a | b | c | d | e | f | g | h | |
| 8 | | | | | | | | | 8 |
| 7 | | | | | | | | | 7 |
| 6 | | | | | | | | | 6 |
| 5 | | | | | | | | | 5 |
| 4 | | | | | | | | | 4 |
| 3 | | | | | | | | | 3 |
| 2 | | | | | | | | | 2 |
| 1 | | | | | | | | | 1 |
| | a | b | c | d | e | f | g | h | |
Black's queen is attacked, and capturing the attacker with 7...bxc6 will end in tears after 8.Bxc6+ Bd7 9.Qh5+! So we have to move the queen. Moving the queen to the fourth rank seems like a good idea, to try and neutralise the discovered check by hitting the b5-bishop, and at the same time cut out any of White's Qh5+ ideas.
Sure enough, the two variations from this position are both queen moves to the fourth rank:
* 7...Qg5 is the Classical Schliemann. The queen counter-attacks the helpless g2-pawn.
* 7...Qd5 is the Möhring Variation. The queen threatens the bishop and, indirectly, the knight with capture. White's only move to hold things together will be 8.c4, after which Black can argue that White's d-pawn is backward on an open file. Whether this is actually relevant with so many tactical possibilities on the board is another matter.
# Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nc6/3. Bb5/3...f5/4. Nc3/4...fxe4/5. Nxe4/5...d5/6. Nxe5/6...dxe4/7. Nxc6/7...Qd5/8. c4

| | a | b | c | d | e | f | g | h | |
| 8 | | | | | | | | | 8 |
| 7 | | | | | | | | | 7 |
| 6 | | | | | | | | | 6 |
| 5 | | | | | | | | | 5 |
| 4 | | | | | | | | | 4 |
| 3 | | | | | | | | | 3 |
| 2 | | | | | | | | | 2 |
| 1 | | | | | | | | | 1 |
| | a | b | c | d | e | f | g | h | |
8...Qd6 is necessary to preserve the attack on the White knight. It's true that Black could have played 7...Qd6 in one move, but the move 8.c4 is hopefully going to prove to be a concession by White.
Horizontal queen moves like 8...Qg5 are inferior because the queen won't be hitting an undefended piece on b5 the way it would after 7...Qg5.
# Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nc6/3. Bb5/3...f5/4. Nc3/4...fxe4/5. Nxe4/5...d5/6. Nxe5/6...dxe4/7. Nxc6/7...Qd5/8. c4/8...Qd6/9. Nxa7/9...Bd7

| | a | b | c | d | e | f | g | h | |
| 8 | | | | | | | | | 8 |
| 7 | | | | | | | | | 7 |
| 6 | | | | | | | | | 6 |
| 5 | | | | | | | | | 5 |
| 4 | | | | | | | | | 4 |
| 3 | | | | | | | | | 3 |
| 2 | | | | | | | | | 2 |
| 1 | | | | | | | | | 1 |
| | a | b | c | d | e | f | g | h | |
White's two threats in this position are Qh5+ and Bxd7+. It doesn't really matter whether White plays
* 10. Bxd7+, or
* 10. Qh5+
first, unless she wants to leave out Qh5+ entirely and just save the a7-knight with 10.Bxd7 Qxd7 11.Nb5. But that plan has a terrible score for White, despite the two extra pawns, because of Black's bind on the d-file and easy development.
# Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nc6/3. Bb5/3...f5/4. Nc3/4...fxe4/5. Nxe4/5...d5/6. Nxe5/6...dxe4/7. Nxc6/7...Qd5/8. c4/8...Qd6/9. Nxa7/9...Bd7/10. Bxd7

| | a | b | c | d | e | f | g | h | |
| 8 | | | | | | | | | 8 |
| 7 | | | | | | | | | 7 |
| 6 | | | | | | | | | 6 |
| 5 | | | | | | | | | 5 |
| 4 | | | | | | | | | 4 |
| 3 | | | | | | | | | 3 |
| 2 | | | | | | | | | 2 |
| 1 | | | | | | | | | 1 |
| | a | b | c | d | e | f | g | h | |
10...Qxd7 is a better recapture than 10...Kxd7, which would give up castling rights for no reason and leave the queen on a square where it would lose a tempo to Nb5.
# Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nc6/3. Bb5/3...f5/4. Nc3/4...fxe4/5. Nxe4/5...d5/6. Nxe5/6...dxe4/7. Nxc6/7...Qd5

| | a | b | c | d | e | f | g | h | |
| 8 | | | | | | | | | 8 |
| 7 | | | | | | | | | 7 |
| 6 | | | | | | | | | 6 |
| 5 | | | | | | | | | 5 |
| 4 | | | | | | | | | 4 |
| 3 | | | | | | | | | 3 |
| 2 | | | | | | | | | 2 |
| 1 | | | | | | | | | 1 |
| | a | b | c | d | e | f | g | h | |
Both of White's developed pieces are threatened with capture, so 8. c4 is necessary to distract the Black queen.
# Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nc6/3. Bb5/3...f5/4. Nc3/4...fxe4/5. Nxe4/5...d5/6. Nxe5/6...dxe4/7. Nxc6/7...Qd5/8. c4/8...Qd6

| | a | b | c | d | e | f | g | h | |
| 8 | | | | | | | | | 8 |
| 7 | | | | | | | | | 7 |
| 6 | | | | | | | | | 6 |
| 5 | | | | | | | | | 5 |
| 4 | | | | | | | | | 4 |
| 3 | | | | | | | | | 3 |
| 2 | | | | | | | | | 2 |
| 1 | | | | | | | | | 1 |
| | a | b | c | d | e | f | g | h | |
9. Nxa7+ was first played in Gligoric-Heidenfeld 1960. It's not entirely clear how Black is going to punish White for simply grabbing a second pawn and holding on to it - on the contrary, White still has the threat of Qh5+ on the board, so it may be Black that gets the punishment.
9. Qh5+ was played against Günther Möhring, the originator of the 7...Qd5 variation, in two Hungarian tournaments in the 1980s. As is usually the case for loud forcing moves, it's actually a little more drawish than the alternative. Black will probably come out of the looming queen trade with castling rights still intact, which isn't the case in the 9. Nxa7+ line.
# Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nc6/3. Bb5/3...f5/4. Nc3/4...fxe4/5. Nxe4/5...d5/6. Nxe5/6...dxe4/7. Nxc6/7...Qd5/8. c4/8...Qd6/9. Nxa7/9...Bd7/10. Bxd7/10...Qxd7

| | a | b | c | d | e | f | g | h | |
| 8 | | | | | | | | | 8 |
| 7 | | | | | | | | | 7 |
| 6 | | | | | | | | | 6 |
| 5 | | | | | | | | | 5 |
| 4 | | | | | | | | | 4 |
| 3 | | | | | | | | | 3 |
| 2 | | | | | | | | | 2 |
| 1 | | | | | | | | | 1 |
| | a | b | c | d | e | f | g | h | |
The main line here is 11. Qh5+. White has the bread and butter of two extra pawns, and wants the jam as well (stopping Black from castling). Black can offer an exchange sacrifice in response, but White shouldn't accept it; the realisation that White isn't obliged to accept it was responsible for 11. Qh5+ taking over as the main line from:
11. Nb5, which seems like it should be enough for a solid advantage. Two pawns are two pawns! But it actually scores rather badly for White. There's a caveat, as there always is with opening statistics: if top players know 11.Qh5+ is playable but weaker players aren't in on the secret, then 11.Nb5 will end up being played by weaker players, and weaker players are more likely to lose.
# Chess Opening Theory/1. e4/1...e5/2. Nf3/2...Nc6/3. Bb5/3...f5/4. Nc3/4...fxe4/5. Nxe4/5...d5/6. Nxe5/6...dxe4/7. Nxc6/7...Qd5/8. c4/8...Qd6/9. Nxa7

| | a | b | c | d | e | f | g | h | |
| 8 | | | | | | | | | 8 |
| 7 | | | | | | | | | 7 |
| 6 | | | | | | | | | 6 |
| 5 | | | | | | | | | 5 |
| 4 | | | | | | | | | 4 |
| 3 | | | | | | | | | 3 |
| 2 | | | | | | | | | 2 |
| 1 | | | | | | | | | 1 |
| | a | b | c | d | e | f | g | h | |
Black isn't thrilled about the prospect of trading pieces when she's two pawns down, but the c8-bishop is coming off the board regardless, so it might as well be with 9...Bd7 which preserves Black's right to castle, rather than with the tempting 9...c6 which runs into 10.Nxc8 hitting the queen.
# Circuit Idea/Various Points of View

The heuristic approach expands, generalizes and reinforces students' understanding of electronic analog devices. For example, we can represent the inverting amplifier from different points of view: negative feedback inverting circuit, voltage-to-voltage converter, cascaded voltage-to-current and current-to-voltage converters, resistance-to-voltage converter, analog multiplier, voltage stabilizer, etc. This approach expands, summarizes and reinforces students' understanding of electronic analog devices.
# Circuit Idea/Using Cause and Effect Relationships
## Revealing causality

Classical electronics courses do not reveal cause and effect relations in electronic circuits. For example, who cares if there is a causality and what causes what (what quantity is an input and what an output) in Ohm's law? Authors just suppose that voltage and current change simultaneously; they do not mind how the famous rule is written (I = V/R, V = I.R or R = V/I).
Also, the classical approach considers active elements as proportional, inertialess devices where the input and output quantities change simultaneously. For example, it is believed that the collector current of a transistor changes simultaneously with its base current, the output voltage of an operational amplifier changes simultaneously with the input its voltage etc. Viewed in this way, the operation of the devices can hardly be understood because the cause-and-effect relationship between the input and output quantities is not visible.
Only, we human beings consider every change in this world as a result of some cause (in electronics that means the output quantity is a result of the input quantity). We cannot imagine that the input and output quantities can change simultaneously. We know that always the input is first and the output is second; so, the output always follows (delays) the input. So, in order to understand the operation of electronic devices, cause and effect relations must be seen.

## Introducing causality

In the case when apparently there is no causality in electronic circuits, we can introduce it. Let's for concreteness consider the example above of Ohm's law. There, we first assume that voltage causes current (I = V/R) in a voltage supplied Ohm's circuit; thus we "invent" the simplest voltage-to-current converter.

## Changing causality

But we know that this cause and effect relation is an arbitrary choice; so, we can change (reverse) it. This means we can assume with the same success that current causes voltage (V = I.R) in a current supplied Ohm's circuit; thus we "invent" the reverse current-to-voltage converter.
Evolving this powerful idea we will (re)invent a lot of useful and original circuits by using any accessible circuit points (including circuit outputs, supply terminals, etc.) and component parameters as an input. For example, varying with resistance as an input quantity we will obtain a resistance-to-current converter (in the case of a voltage supplied Ohm's circuit) and a resistance-to-voltage converter (in the case of a current supplied Ohm's circuit). Then, applying an input voltage to the output of an emitter follower we will "invent" the odd common-base transistor amplifying stage. Later, changing causality, we will transmute a digital-to-analog converter into a digital controlled amplifier.
# Basics of fine-art photography/Creating works in panoramic photography

Panoramic photography is a catch-all term that characterizes a set of methods that make it possible to obtain images with a viewing angle of up to 360º.

## General information

Panoramic (or wide-format) photography contributes to the display of objects that cannot be captured in the frame using regular and wide-angle lenses.
It can be horizontal (more often), or vertical; used for shooting natural and urban landscapes, interiors of buildings.
The advantage over a photograph taken with a wide-angle lens is the absence of distortion: if in landscape photography they are almost invisible, then in interior photography, alas.

## Ways of implementation

Many modern cameras (including the simplest) have a panorama photo function, the algorithm of which differs depending on the model used.
* By instantaneous automatic docking of several sequentially made frames, where an auxiliary horizontal line and a small fragment of the previous frame allows you to minimize errors. The variant, where docking is noticeable (in this case, three frames) can be seen here: example.
* Some models offer to move the lens smoothly (as when shooting a video), resulting in a panoramic photo.
* There is such a variation: when the “panorama” mode is set, the camera captures standard frames that should be joined on the computer. The disadvantage of this method is that if the number of frames on the flash drive is in the hundreds or even thousands (as happens with the author of this textbook in long expeditions involving visits to ten or more countries), it is easy to confuse the frames intended to be combined with the rest, and delete part of them by mistake.
In addition to the above methods, you can create a horizontal panoramic image using a camera that doesn't have such a function: will need a tripod with a rotating head.
For an in-depth study of the topic, see the "Panoramic cameras and methods section" of the Wikipedia article.

## Gallery

The photos were taken during the author's 200-day solo expedition (2014 - 2015).
* Ciudad del Encanto, Bolivia (photo from book "Two hundred days in Latin America")
* Laguna Colorada, Bolivia
* Cusco (view from Sacsayhuamán), Peru
* Iguazu Falls (Foz do Iguaçu), Brazil
* Perito Moreno Glacier, Argentina (photo from book "Two hundred days in Latin America")
* Guatemala City
# Basics of fine-art photography/Creating works in photoart

Photoart is a type of fine art that combines photography and computer graphics.

## General information

Photomontage was used at the end of the last century and even earlier, but with the development of computer technology, creative people got unlimited opportunities for realize fantasies.
The photo collages created by the authors of past years have been left far behind, they have been replaced by works of art that are distinguished by a significant processing of the source material, visual effects and a higher artistic level. Sometimes the creations of masters of photoart imitate painting, but the result always based on photography, only in our time, digital has replaced analog image.
If the theme of works has fantasy, fabulous, mystical shades, — photoart intersects with other genres and directions.

## Ways of implementation

The first and necessary condition is that you, a novice photographer, must have some degree of imagination. The source images can be created on purpose — for the realization of a particular idea or a series of works united by a conceptual idea, or, if you have a stock of ready-made photographs, you can use something from them as raw material.
A positive effect can be achieved by combining two or three source files into one, followed by processing by filters of graphics editors. It is difficult to predict the result, you need improvisation.
To begin with, you can practice creating relatively simple images, examples of which are illustrated in this tutorial article.

## See also

Creating works in neosurrealism photography

## Gallery

* Illustration for the literary miniature "Strange dream"
* Sunset
* Illustration for the literary miniature «Провинциальная история»
* Eclipse
* Illustration for the literary miniature "Persian tale"
# Basics of fine-art photography/Creating works in macro photography

Macro photography is the creation of optical images, where, according to the Great Russian Encyclopedia, the scale is from 1:5 to 10:1 or higher.

## General information

The method is used to display small objects in full size or with magnification; (the smallest objects are displayed using photomicrograph).
For professional purposes, special accessories are used: supplementary lenses, extension rings, short-throw lens, etc.

## Ways of implementation

With the simplest digital camera, you can get a decent result. Many "point-and-shoot" models have a “macro” mode, using which, you should bring the camera closer to the object being shot, while not forgetting to increase the shutter speed, because the image illumination decreases as the distance decreases. If your model has a depth-of-field option, use the maximum setting to ensure that the finest details are captured.
In any case, in the era of digital technology, trial and error will help.
The use of bulky detachable lenses and tripods, contradicts the principles of the author, who is a supporter of hobo tourism, so if you are interested in an in-depth understanding of macro photography theory, look at the works of creator this article, which were made with a primitive camera and... try to find another textbook — more thorough and detailed one.

## Gallery

* Woodlouse (Malaysia) Photo taken on a Papuan expedition
* Onymacris unguicularis (Sudan) Photo taken on a Third creative trip to Africa
* Dactylotum bicolor (Namibia) Photo taken on a Third creative trip to Africa
* Scolopendra cingulata(Thailand) Photo taken on a Papuan expedition
* Caterpillar (Russia) Photo taken in Crimea