{"id":1192,"date":"2024-07-31T12:00:04","date_gmt":"2024-07-31T10:00:04","guid":{"rendered":"https:\/\/blog.sutilweb.eu\/?page_id=1192"},"modified":"2024-07-31T12:00:06","modified_gmt":"2024-07-31T10:00:06","slug":"03-selectores-css","status":"publish","type":"page","link":"https:\/\/sutilweb.eu\/index.php\/lenguajes\/css3\/css3-basico\/03-selectores-css\/","title":{"rendered":"03. Selectores CSS"},"content":{"rendered":"\n

Un selector<\/strong> de CSS<\/strong> selecciona los elementos HTML<\/strong> que deseas dise\u00f1ar.<\/p>\n\n\n\n\n\n\n\n

Selectores CSS<\/h2>\n\n\n\n

Los selectores<\/strong> de CSS<\/strong> se utilizan para \u00abencontrar\u00bb (o seleccionar) los elementos HTML<\/strong> que deseamos dise\u00f1ar.<\/p>\n\n\n\n

Podemos dividir los selectores en 5 categor\u00edas:<\/p>\n\n\n\n

    \n
  • Selectores simples<\/strong>: seleccionan elementos basados en nombre, id<\/em><\/strong>, class<\/em><\/strong>…<\/li>\n\n\n\n
  • Selectores combinadores<\/strong>: seleccionan elementos en funci\u00f3n de una relaci\u00f3n espec\u00edfica entre ellos<\/li>\n\n\n\n
  • Selectores de pseudoclase<\/strong>: seleccionan elementos en funci\u00f3n de un determinado estado<\/li>\n\n\n\n
  • Selectores de pseudoelementos<\/strong>: seleccionan y dise\u00f1an una parte de un elemento<\/li>\n\n\n\n
  • Selectores de atributos<\/strong>: seleccionan elementos en funci\u00f3n de un atributo o valor de atributo<\/li>\n<\/ul>\n\n\n\n

    El selector de elementos CSS<\/h2>\n\n\n\n

    El selector de elementos<\/strong> selecciona elementos HTML en funci\u00f3n del nombre del elemento.<\/p>\n\n\n\n

    Ejm<\/strong><\/p>\n\n\n\n

    p {\n  text-align: center;\n  color: red;\n}<\/pre>\n\n\n\n
    El selector de id<\/h2>\n\n\n\n
    El selector de id<\/strong> usa el atributo id<\/em><\/strong> de un elemento HTML para seleccionar un elemento espec\u00edfico. La identificaci\u00f3n de un elemento es \u00fanica dentro de una p\u00e1gina, por lo que el selector de id<\/strong> se usa para seleccionar un elemento \u00fanico. Para seleccionar un elemento con una identificaci\u00f3n espec\u00edfica, escribe un car\u00e1cter hash (#), seguido de la identificaci\u00f3n del elemento.<\/p>\n\n\n\n
    Ejm<\/strong><\/p>\n\n\n\n
    #para1 {\n  text-align: center;\n  color: red;\n}<\/pre>\n\n\n\n
    \n
    Nota<\/strong>: Un nombre de id no puede comenzar con un n\u00famero.<\/p>\n<\/blockquote>\n\n\n\n
    El selector CSS class<\/h2>\n\n\n\n
    El selector class<\/em><\/strong> selecciona elementos HTML con un atributo de clase espec\u00edfico. Para seleccionar elementos con una clase espec\u00edfica, escribe un car\u00e1cter de punto (.), seguido del nombre de la clase.<\/p>\n\n\n\n
    Ejm<\/strong><\/p>\n\n\n\n
    .center {\n  text-align: center;\n  color: red;\n}<\/pre>\n\n\n\n
    Tambi\u00e9n puedes especificar que solo los elementos HTML espec\u00edficos se vean afectados por una clase.<\/p>\n\n\n\n
    Ejm<\/strong><\/p>\n\n\n\n
    <!DOCTYPE html>\n<html>\n<head>\n<style>\np.center {\ntext-align: center;\ncolor: red;\n}\n<\/style>\n<\/head>\n<body>\n\n<h1 class=\"center\">Este encabezado no se ver\u00e1 afectado<\/h1>\n<p class=\"center\">Este p\u00e1rrafo se ver\u00e1 alineado al centro<\/p>\n\n<\/body>\n<\/html><\/pre>\n\n\n\n
    Los elementos HTML tambi\u00e9n pueden referirse a m\u00e1s de una clase.<\/p>\n\n\n\n
    Ejm<\/strong><\/p>\n\n\n\n
    En este ejemplo, el elemento <p><\/em><\/strong> se dise\u00f1ar\u00e1 de acuerdo con class=\u00bbcenter\u00bb<\/em><\/strong> y class=\u00bblarge\u00bb<\/em><\/strong>.<\/p>\n\n\n\n
    <!DOCTYPE html>\n<html>\n<head>\n<style>\np.center {\ntext-align: center;\ncolor: red;\n}\n\np.large {\nfont-size: 300%;\n}\n<\/style>\n<\/head>\n<body>\n\n<h1 class=\"center\">Este encabezado no ser\u00e1 afectado<\/h1>\n<p class=\"center\">Este p\u00e1rrafo ser\u00e1 rojo y alineado al centro<\/p>\n<p class=\"center large\">Este p\u00e1rrafo ser\u00e1 rojo, alineado alcentro\ny con un tama\u00f1o large.<\/p>\n\n<\/body>\n<\/html><\/pre>\n\n\n\n
    \n
    Nota<\/strong>: Un nombre de clase no puede comenzar con un n\u00famero.<\/p>\n<\/blockquote>\n\n\n\n
    El selector CSS universal<\/h2>\n\n\n\n
    El selector universal<\/strong> (*) selecciona todos los elementos HTML de la p\u00e1gina.<\/p>\n\n\n\n
    Ejm<\/strong><\/p>\n\n\n\n
    <!DOCTYPE html>\n<html>\n<head>\n<style>\n* {\ntext-align: center;\ncolor: blue;\n}\n<\/style>\n<\/head>\n<body>\n\n<h1>Hola Mundo!<\/h1>\n\n<p>Cada elemento en la p\u00e1gina ser\u00e1 afectado por el estilo.<\/p>\n<p id=\"para1\">Este p\u00e1rrafo se ver\u00e1 afectado<\/p>\n<p>Este otro tambi\u00e9n<\/p>\n\n<\/body>\n<\/html><\/pre>\n\n\n\n
    El selector de agrupaci\u00f3n CSS<\/h2>\n\n\n\n
    El selector de agrupaci\u00f3n<\/strong> selecciona todos los elementos HTML con las mismas definiciones de estilo. Mira el siguiente c\u00f3digo CSS (los elementos h1<\/em><\/strong>, h2<\/em><\/strong> y p<\/em><\/strong> tienen las mismas definiciones de estilo).<\/p>\n\n\n\n
    Ejm<\/strong><\/p>\n\n\n\n
    h1 {\n  text-align: center;\n  color: red;\n}\n\nh2 {\n  text-align: center;\n  color: red;\n}\n\np {\n  text-align: center;\n  color: red;\n}<\/pre>\n\n\n\n
    Lo mejor es agrupar los selectores, para minimizar el c\u00f3digo. Para agrupar selectores, separa cada selector con una coma.<\/p>\n\n\n\n
    Ejm<\/strong><\/p>\n\n\n\n
    <!DOCTYPE html>\n<html>\n<head>\n<style>\nh1, h2, p {\ntext-align: center;\ncolor: red;\n}\n<\/style>\n<\/head>\n<body>\n\n<h1>Hello World!<\/h1>\n<h2>Smaller heading!<\/h2>\n<p>This is a paragraph.<\/p>\n\n<\/body>\n<\/html><\/pre>\n\n\n\n
    Todos los selectores simples<\/h2>\n\n\n\n
    Selector<\/th>Ejemplo<\/th>Descripci\u00f3n del ejemplo<\/th><\/tr>
    #id<\/em><\/strong><\/td>#firstname<\/td>Selecciona el elemento con la  id=\u00bbfirstname\u00bb<\/td><\/tr>
    .class<\/em><\/strong><\/td>.intro<\/td>Selecciona todos los elementos con class=\u00bbintro\u00bb<\/td><\/tr>
    element.class<\/em><\/strong><\/td>p.intro<\/td>Selecciona s\u00f3lo los elementos <p><\/em><\/strong> con class=\u00bbintro\u00bb<\/td><\/tr>
    *<\/strong><\/td>*<\/td>Selecciona todos los elementos<\/td><\/tr>
    element<\/em><\/strong><\/td>p<\/td>Selecciona los elementos <p><\/em><\/strong><\/td><\/tr>
    element, element,..<\/em><\/strong><\/td>div, p<\/td>Selecciona todos los elementos <div><\/em> y todos los elementos <p><\/em><\/strong><\/td><\/tr><\/tbody><\/table><\/figure>\n","protected":false},"excerpt":{"rendered":"
    Un selector de CSS selecciona los elementos HTML que deseas dise\u00f1ar.<\/p>\n","protected":false},"author":1,"featured_media":0,"parent":563,"menu_order":2,"comment_status":"closed","ping_status":"closed","template":"","meta":{"_uag_custom_page_level_css":"","site-sidebar-layout":"default","site-content-layout":"","ast-site-content-layout":"default","site-content-style":"default","site-sidebar-style":"default","ast-global-header-display":"","ast-banner-title-visibility":"","ast-main-header-display":"","ast-hfb-above-header-display":"","ast-hfb-below-header-display":"","ast-hfb-mobile-header-display":"","site-post-title":"","ast-breadcrumbs-content":"","ast-featured-img":"","footer-sml-layout":"","ast-disable-related-posts":"","theme-transparent-header-meta":"","adv-header-id-meta":"","stick-header-meta":"","header-above-stick-meta":"","header-main-stick-meta":"","header-below-stick-meta":"","astra-migrate-meta-layouts":"default","ast-page-background-enabled":"default","ast-page-background-meta":{"desktop":{"background-color":"var(--ast-global-color-4)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"ast-content-background-meta":{"desktop":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"tablet":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""},"mobile":{"background-color":"var(--ast-global-color-5)","background-image":"","background-repeat":"repeat","background-position":"center center","background-size":"auto","background-attachment":"scroll","background-type":"","background-media":"","overlay-type":"","overlay-color":"","overlay-opacity":"","overlay-gradient":""}},"footnotes":""},"class_list":["post-1192","page","type-page","status-publish","hentry"],"uagb_featured_image_src":{"full":false,"thumbnail":false,"medium":false,"medium_large":false,"large":false,"1536x1536":false,"2048x2048":false},"uagb_author_info":{"display_name":"Sutil Web","author_link":"https:\/\/sutilweb.eu\/index.php\/author\/sutilweb\/"},"uagb_comment_info":0,"uagb_excerpt":"Un selector de CSS selecciona los elementos HTML que deseas dise\u00f1ar.","_links":{"self":[{"href":"https:\/\/sutilweb.eu\/index.php\/wp-json\/wp\/v2\/pages\/1192","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/sutilweb.eu\/index.php\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/sutilweb.eu\/index.php\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/sutilweb.eu\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/sutilweb.eu\/index.php\/wp-json\/wp\/v2\/comments?post=1192"}],"version-history":[{"count":2,"href":"https:\/\/sutilweb.eu\/index.php\/wp-json\/wp\/v2\/pages\/1192\/revisions"}],"predecessor-version":[{"id":1194,"href":"https:\/\/sutilweb.eu\/index.php\/wp-json\/wp\/v2\/pages\/1192\/revisions\/1194"}],"up":[{"embeddable":true,"href":"https:\/\/sutilweb.eu\/index.php\/wp-json\/wp\/v2\/pages\/563"}],"wp:attachment":[{"href":"https:\/\/sutilweb.eu\/index.php\/wp-json\/wp\/v2\/media?parent=1192"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}