Simetricks

CSS

publié le 13/06/2020 à 16h15 | modifé le 13/06/2020 à 19h00
Catégorie : Langages | Commentaires (1096)

Description

Le CSS (Cascading Styles Sheets) est un langage informatique permettant de décrire le style, la présentation d'un document HTML. Là où le HTML va se contenter de structurer un document, le CSS va prendre en charge le style, la mise en page d'une page web.

En réalité, le HTML n'a jamais eu besoin du langage CSS pour être exécuté sur un navigateur web. Cependant, le CSS est devenu rapidement une nécessité afin de séparer ce qui relève purement et simplement de la structure d'une page web (c'est le rôle du HTML), de ce qui relève de la mie en page (formes, couleurs, polices de caractères....).

Le style d'une page web peut être défini de 3 façons :

-soit directement dans la page HTML (avec par exemple la balise style, située dans la partie HEAD de la page)

-soit en mode inline (exemple : utilisation de la balise strong pour mettre en gras un texte)

-soit grâce à un fichier CSS, référencé dans la section HEAD de la page.

Il est évident qu'il est préférable d'utiliser la 3ème méthode. En effet : imaginons qu'un développeur souhaite modifier complètement le design d'un site web, sans pour autant modifier la structure des pages web. C'est là que le fichier CSS a son intérêt : le développeur pourra modifier le style du site en ne modifiant que le fichier CSS du site. Ce sera d'autant plus utile si le site web contient de très nombreuses pages.

Il est possible également qu'une page web ou qu'un site fasse appel à plusieurs fichiers CSS. Par exemple, il est fréquent de voir un fichier CSS différent pour chaque taille d'écran, afin de rendre un site 100% responsive.

Par ailleurs, le CSS est devenu de plus en plus puissant au fil des années. Désormais, le CSS permet d'afficher par exemple des animations, ou des graphiques particulièrement complexes.

Les sélecteurs

Le principe du CSS repose sur la sélection : on sélecte un élément (par exemple un type de balise, ou bien une balise possédant un identifiant) pour lui appliquer un style. On pourra par exemple appliquer une couleur rouge pour tous les titres de type H3.

Box Model

Tous les élements HTML (une image, un paragraphe, un formulaire...) peut être considéré comme une boîte. Pour définir cette boîte, on utilise 4 élements :

- Margin (Marge - l'espace qui est en dehors de la bordure)

- Border (Bordure - la bordure qui est autour du padding)

- Padding (Ecart - l'écart entre le contenu et la bordure)

- Content (Contenu - par exemple le texte et les images)

Grid

Grid est un principe CSS permettant d'afficher un Layout en mode "grille". Le développeur peut utiliser ce principe pour positionner des éléments dans une grille, en faisant varier par exemple la taille de chaque case, ou l'orientation de chaque rangée, etc...

Pour afficher un layout en mode Grid, il est nécessaire d'insérer l'instruction display: grid

Flexbox

Auparavant, nous avions 4 formats de Layouts possibles :

- Block, pour les sections d'une page

- Inline, pour le texte

- Table, pour afficher un tableau

- Positioned, pour positionner explicitement un élément.

L'arrivée du concept du Flexbox facilite la création de layout, sans avoir à utiliser les notions de float ou de position.

Pour activer la notion de flexbox sur un élément, il est nécessaire d'appliquer un affichage flex avec l'instruction display: flex

Les proprités d'un conteneur Flex sont les suivantes :

flex-direction

flex-wrap

flex-flow

justify-content

align-items

align-content

Fonctionnalités

Style / Mise en page

Date de création

17/12/1996

Créateur

W3C

Dernière version

Langage

CSS

Liens

w3.org/Style/CSS/

Aux dernières nouvelles

Depuis 2010, CSS est censé évoluer vers sa version 4. Mais suite au succès de HTML 5 couplé avec CSS 3, il est possible que CSS 4 ne voit jamais le jour, où bien que la notion de version (5 pour HTML et 3 pour CSS) disparaisse, pour devenir des langages en constante évolution.

1096 Commentaire(s)

JeffryMer

11/04/2025 à 09h50 commentaire modifé

Hidden Link Placement in Established Content Hubs Hey there! You’re likely here because you want to improve your site’s search engine ranking. Let’s face it — navigating SEO can be daunting, especially with so many “quick-fix” services out there claiming guaranteed results that rarely materialize. That’s why I want to share my strategy with you. It’s not just another one-size-fits-all package — it’s a bespoke approach designed to deliver tangible growth. I specialize in building link pyramids that combine Tier 1, Tier 2, and Tier 3 backlinks. Picture creating a reliable framework for your project. Without a solid base, everything else crumbles. My goal is to drive authority straight to your money site in a way that mimics organic growth and delivers results. Why Should You Trust Me? To be straightforward: I’ve been in the search engine optimization industry for years, and I’ve witnessed every trend — successful strategies and outright scams. I’ve worked with clients who wasted hundreds (sometimes thousands) on services that promised “guaranteed rankings” but caused ranking drops. That’s why I decided to redefine the process. I focus on premium follow-backlinks from authoritative websites. The majority of top-layer backlinks in my strategy are dofollow because they deliver the strongest impact. And here’s the clincher — you’ll get this high-end solution at significantly reduced rates (we’re talking 200–350forthesamepackage?pricesstartaslowas200). How does wasting money help? Protect your budget ?? in something that actually works. The Secret Sauce High Authority Guest Posts I don’t just throw your links on any random blog. Nope. I carefully select only the top-tier platforms — platforms with strong domain authority (DA). These are the kinds of sites that skyrocket your rankings. Unique, Handwritten Content Low-quality writing harms credibility. It’s boring, unnatural, and frankly, a waste of time. That’s why every piece I create is original, compelling, and customized for your industry. Whether it’s for Web 2.0 properties, I guarantee plagiarism-free results that supports your strategy organically. No shortcuts, no fluff — just high-quality writing that gets results. Three-Layer Link Building Strategy Here’s where things get powerful. My method builds depth by incorporating Tier 2 and Tier 3 support links. This layered approach multiplies the impact of your core links, driving long-term success for your money site. Think of it like a snowball rolling downhill — it starts small but gains momentum. Multi-Platform Authority Building A natural profile requires eclectic sources, so I use a mix high-authority sources: media channels, directories, and niche forums. This isn’t about exploiting loopholes; it’s about building something that lasts. No Hidden Agendas When you work with me, you’ll know exactly what you’re getting. I provide a comprehensive breakdown, including login details for all Web 2.0 properties. No secrets, no hidden agendas — just complete transparency. You’ll monitor each placement and how they’re helping your site grow. A Little Story from My Experience Here’s a real example: A few years ago, I worked with a client who was disappointed with their site’s performance despite months of effort. They’d tried multiple agencies, but results were elusive. When they came to me, I crafted a custom plan. A personalized approach was implemented. In 60 days, organic visits surged, and they started seeing real conversions. That’s the kind of result I aim for with every client. Let’s build your path to the top Drop me a line today and turn search engines into your ally. ??

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11/04/2025 à 04h48 commentaire modifé

Hi there! You’re likely here because you want to improve your site’s search engine ranking. I get it — SEO can feel overwhelming, especially with so many “quick-fix” services out there promising the moon but delivering… well, not much. That’s why I want to share my strategy with you. It’s not just another cookie-cutter service — it’s a personalized strategy designed to deliver tangible growth. I specialize in building tiered authority systems that combine strategic link layers. Think of it like constructing a strong foundation for your house. A weak foundation leads to instability. My goal is to boost your primary domain’s credibility in a way that feels natural to Google and actually works. Why Should You Trust Me? To be straightforward: I’ve been in the SEO game for years, and I’ve experienced the full spectrum — the good, the bad, and the downright spammy. I’ve worked with clients who invested heavily on services that vowed top positions but resulted in search engine bans. That’s why I decided to redefine the process. I focus on high-quality, dofollow backlinks from authoritative websites. The majority of top-layer backlinks in my strategy are dofollow because they pack the biggest punch. And here’s the catch — you’ll get this premium service at a fraction of what others charge (costing just 200–350 USD). Why pay more for less? Invest wisely in something that delivers real ROI. The Secret Sauce Premium Content Placement I don’t just throw your links on any random blog. Nope. I handpick only the most reputable guest post sites — websites Google prioritizes. These are the kinds of sites that elevate your domain’s credibility. Unique, Handwritten Content AI-generated text is easily spotted. It’s boring, unnatural, and frankly, a waste of time. That’s why every piece I create is 100% unique, engaging, and customized for your industry. Whether it’s for private blog networks (PBNs), I guarantee originality reports that enhances your brand’s voice. No shortcuts, no fluff — just high-quality writing that gets results. Multi-Tiered Authority System Here’s where things get powerful. My method doesn’t stop at Tier 1 by incorporating secondary and tertiary layers. This structured system strengthens the effect of your core links, driving long-term success for your money site. Imagine an avalanche effect, compounding over time. Varied Backlink Portfolio A natural profile requires eclectic sources, so I leverage multiple high-authority sources: media channels, directories, and niche forums. This isn’t about exploiting loopholes; it’s about building something that lasts. Complete Honesty When you work with me, you’ll see every detail. I provide a comprehensive breakdown, including login details for all Web 2.0 properties. Full disclosure at every step. You’ll track every backlink source and their impact on rankings. A Client Success Tale Here’s a real example: A few years ago, I worked with a client who was struggling to gain traction despite prior investments. They’d tried multiple agencies, but progress stalled. When they came to me, I crafted a custom plan. We designed a strategy aligned with their industry. In 60 days, organic visits surged, and they achieved measurable sales growth. That’s the kind of success I strive to deliver with every client. Ready to elevate your SEO game? Drop me a line today and start your journey to #1. ??

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JeffryMer

11/04/2025 à 03h16 commentaire modifé

Hello! If you’re reading this, chances are you’re looking for a way to boost your website’s visibility in Google. I understand — mastering SEO might seem intimidating, especially with so many “instant results” offers out there claiming guaranteed results that rarely materialize. That’s why I want to share my approach with you. It’s not just another one-size-fits-all package — it’s a personalized strategy designed to deliver concrete improvements. I specialize in building link pyramids that combine strategic link layers. Imagine building a sturdy base for a skyscraper. A weak foundation leads to instability. My goal is to drive authority straight to your money site in a way that feels natural to Google and delivers results. What Makes Me Different? Let me be honest here: I’ve been in the SEO game for years, and I’ve witnessed every trend — the good, the bad, and the downright spammy. I’ve worked with clients who wasted hundreds (sometimes thousands) on services that promised “guaranteed rankings” but caused ranking drops. That’s why I decided to redefine the process. I focus on premium follow-backlinks from authoritative websites. Over 80% of Tier 1 links in my strategy are dofollow because they deliver the strongest impact. And here’s the clincher — you’ll get this top-tier offering at discounted pricing (we’re talking 200–350forthesamepackage?pricesstartaslowas200). Why pay more for less? Protect your budget ?? in something that guarantees progress. The Secret Sauce Premium Content Placement No generic outreach here. Nope. I handpick only the top-tier platforms — sites boasting high trust flow (TF). These are the kinds of sites that skyrocket your rankings. Original, Custom-Crafted Articles Low-quality writing harms credibility. It’s boring, unnatural, and frankly, a waste of time. That’s why every piece I create is plagiarism-free, engaging, and customized for your industry. Whether it’s for private blog networks (PBNs), I guarantee originality reports that supports your strategy organically. No shortcuts, no fluff — just high-quality writing that gets results. Three-Layer Link Building Strategy Here’s where things get powerful. My method doesn’t stop at Tier 1 by incorporating mid-level and foundational backlinks. This layered approach multiplies the impact of your core links, driving steady progress for your money site. Think of it like a snowball rolling downhill — it starts small but gains momentum. Diverse Link Sources A natural profile requires eclectic sources, so I use a mix high-authority sources: media channels, directories, and niche forums. This isn’t about gaming the system; it’s about building something that lasts. Complete Honesty When you work with me, you’ll see every detail. I provide a comprehensive breakdown, including access credentials. Clear communication, no surprises. You’ll track every backlink source and their role in your success. A Little Story from My Experience Here’s a real example: A few years ago, I worked with a client who was frustrated because their website wasn’t ranking despite prior investments. They’d tried multiple agencies, but nothing seemed to work. When they came to me, I crafted a custom plan. A personalized approach was implemented. Within a few months, their traffic doubled, and they achieved measurable sales growth. That’s the kind of result I aim for with every client. Ready to elevate your SEO game? Contact me now and start your journey to #1. ??

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JeffryMer

11/04/2025 à 09h50 commentaire modifé

Hidden Link Placement in Established Content Hubs Hey there! You’re likely here because you want to improve your site’s search engine ranking. Let’s face it — navigating SEO can be daunting, especially with so many “quick-fix” services out there claiming guaranteed results that rarely materialize. That’s why I want to share my strategy with you. It’s not just another one-size-fits-all package — it’s a bespoke approach designed to deliver tangible growth. I specialize in building link pyramids that combine Tier 1, Tier 2, and Tier 3 backlinks. Picture creating a reliable framework for your project. Without a solid base, everything else crumbles. My goal is to drive authority straight to your money site in a way that mimics organic growth and delivers results. Why Should You Trust Me? To be straightforward: I’ve been in the search engine optimization industry for years, and I’ve witnessed every trend — successful strategies and outright scams. I’ve worked with clients who wasted hundreds (sometimes thousands) on services that promised “guaranteed rankings” but caused ranking drops. That’s why I decided to redefine the process. I focus on premium follow-backlinks from authoritative websites. The majority of top-layer backlinks in my strategy are dofollow because they deliver the strongest impact. And here’s the clincher — you’ll get this high-end solution at significantly reduced rates (we’re talking 200–350forthesamepackage?pricesstartaslowas200). How does wasting money help? Protect your budget ?? in something that actually works. The Secret Sauce High Authority Guest Posts I don’t just throw your links on any random blog. Nope. I carefully select only the top-tier platforms — platforms with strong domain authority (DA). These are the kinds of sites that skyrocket your rankings. Unique, Handwritten Content Low-quality writing harms credibility. It’s boring, unnatural, and frankly, a waste of time. That’s why every piece I create is original, compelling, and customized for your industry. Whether it’s for Web 2.0 properties, I guarantee plagiarism-free results that supports your strategy organically. No shortcuts, no fluff — just high-quality writing that gets results. Three-Layer Link Building Strategy Here’s where things get powerful. My method builds depth by incorporating Tier 2 and Tier 3 support links. This layered approach multiplies the impact of your core links, driving long-term success for your money site. Think of it like a snowball rolling downhill — it starts small but gains momentum. Multi-Platform Authority Building A natural profile requires eclectic sources, so I use a mix high-authority sources: media channels, directories, and niche forums. This isn’t about exploiting loopholes; it’s about building something that lasts. No Hidden Agendas When you work with me, you’ll know exactly what you’re getting. I provide a comprehensive breakdown, including login details for all Web 2.0 properties. No secrets, no hidden agendas — just complete transparency. You’ll monitor each placement and how they’re helping your site grow. A Little Story from My Experience Here’s a real example: A few years ago, I worked with a client who was disappointed with their site’s performance despite months of effort. They’d tried multiple agencies, but results were elusive. When they came to me, I crafted a custom plan. A personalized approach was implemented. In 60 days, organic visits surged, and they started seeing real conversions. That’s the kind of result I aim for with every client. Let’s build your path to the top Drop me a line today and turn search engines into your ally. ??

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11/04/2025 à 04h48 commentaire modifé

Hi there! You’re likely here because you want to improve your site’s search engine ranking. I get it — SEO can feel overwhelming, especially with so many “quick-fix” services out there promising the moon but delivering… well, not much. That’s why I want to share my strategy with you. It’s not just another cookie-cutter service — it’s a personalized strategy designed to deliver tangible growth. I specialize in building tiered authority systems that combine strategic link layers. Think of it like constructing a strong foundation for your house. A weak foundation leads to instability. My goal is to boost your primary domain’s credibility in a way that feels natural to Google and actually works. Why Should You Trust Me? To be straightforward: I’ve been in the SEO game for years, and I’ve experienced the full spectrum — the good, the bad, and the downright spammy. I’ve worked with clients who invested heavily on services that vowed top positions but resulted in search engine bans. That’s why I decided to redefine the process. I focus on high-quality, dofollow backlinks from authoritative websites. The majority of top-layer backlinks in my strategy are dofollow because they pack the biggest punch. And here’s the catch — you’ll get this premium service at a fraction of what others charge (costing just 200–350 USD). Why pay more for less? Invest wisely in something that delivers real ROI. The Secret Sauce Premium Content Placement I don’t just throw your links on any random blog. Nope. I handpick only the most reputable guest post sites — websites Google prioritizes. These are the kinds of sites that elevate your domain’s credibility. Unique, Handwritten Content AI-generated text is easily spotted. It’s boring, unnatural, and frankly, a waste of time. That’s why every piece I create is 100% unique, engaging, and customized for your industry. Whether it’s for private blog networks (PBNs), I guarantee originality reports that enhances your brand’s voice. No shortcuts, no fluff — just high-quality writing that gets results. Multi-Tiered Authority System Here’s where things get powerful. My method doesn’t stop at Tier 1 by incorporating secondary and tertiary layers. This structured system strengthens the effect of your core links, driving long-term success for your money site. Imagine an avalanche effect, compounding over time. Varied Backlink Portfolio A natural profile requires eclectic sources, so I leverage multiple high-authority sources: media channels, directories, and niche forums. This isn’t about exploiting loopholes; it’s about building something that lasts. Complete Honesty When you work with me, you’ll see every detail. I provide a comprehensive breakdown, including login details for all Web 2.0 properties. Full disclosure at every step. You’ll track every backlink source and their impact on rankings. A Client Success Tale Here’s a real example: A few years ago, I worked with a client who was struggling to gain traction despite prior investments. They’d tried multiple agencies, but progress stalled. When they came to me, I crafted a custom plan. We designed a strategy aligned with their industry. In 60 days, organic visits surged, and they achieved measurable sales growth. That’s the kind of success I strive to deliver with every client. Ready to elevate your SEO game? Drop me a line today and start your journey to #1. ??

11/04/2025 à 03h16 commentaire modifé

Hello! If you’re reading this, chances are you’re looking for a way to boost your website’s visibility in Google. I understand — mastering SEO might seem intimidating, especially with so many “instant results” offers out there claiming guaranteed results that rarely materialize. That’s why I want to share my approach with you. It’s not just another one-size-fits-all package — it’s a personalized strategy designed to deliver concrete improvements. I specialize in building link pyramids that combine strategic link layers. Imagine building a sturdy base for a skyscraper. A weak foundation leads to instability. My goal is to drive authority straight to your money site in a way that feels natural to Google and delivers results. What Makes Me Different? Let me be honest here: I’ve been in the SEO game for years, and I’ve witnessed every trend — the good, the bad, and the downright spammy. I’ve worked with clients who wasted hundreds (sometimes thousands) on services that promised “guaranteed rankings” but caused ranking drops. That’s why I decided to redefine the process. I focus on premium follow-backlinks from authoritative websites. Over 80% of Tier 1 links in my strategy are dofollow because they deliver the strongest impact. And here’s the clincher — you’ll get this top-tier offering at discounted pricing (we’re talking 200–350forthesamepackage?pricesstartaslowas200). Why pay more for less? Protect your budget ?? in something that guarantees progress. The Secret Sauce Premium Content Placement No generic outreach here. Nope. I handpick only the top-tier platforms — sites boasting high trust flow (TF). These are the kinds of sites that skyrocket your rankings. Original, Custom-Crafted Articles Low-quality writing harms credibility. It’s boring, unnatural, and frankly, a waste of time. That’s why every piece I create is plagiarism-free, engaging, and customized for your industry. Whether it’s for private blog networks (PBNs), I guarantee originality reports that supports your strategy organically. No shortcuts, no fluff — just high-quality writing that gets results. Three-Layer Link Building Strategy Here’s where things get powerful. My method doesn’t stop at Tier 1 by incorporating mid-level and foundational backlinks. This layered approach multiplies the impact of your core links, driving steady progress for your money site. Think of it like a snowball rolling downhill — it starts small but gains momentum. Diverse Link Sources A natural profile requires eclectic sources, so I use a mix high-authority sources: media channels, directories, and niche forums. This isn’t about gaming the system; it’s about building something that lasts. Complete Honesty When you work with me, you’ll see every detail. I provide a comprehensive breakdown, including access credentials. Clear communication, no surprises. You’ll track every backlink source and their role in your success. A Little Story from My Experience Here’s a real example: A few years ago, I worked with a client who was frustrated because their website wasn’t ranking despite prior investments. They’d tried multiple agencies, but nothing seemed to work. When they came to me, I crafted a custom plan. A personalized approach was implemented. Within a few months, their traffic doubled, and they achieved measurable sales growth. That’s the kind of result I aim for with every client. Ready to elevate your SEO game? Contact me now and start your journey to #1. ??