Maîtrise CSS Grid : Guide Complet avec Exemples Réels 2026

CSS Grid est le système de mise en page le plus puissant jamais ajouté au CSS. En 2026, les fonctionnalités Grid Level 2 comme subgrid sont entièrement prises en charge.

Bases de Grid : colonnes, lignes et placement

Grid crée un système de coordonnées bidimensionnel.

/* CSS Grid fundamentals */
.grid-container {
    display: grid;

    /* Define columns */
    grid-template-columns: 200px 1fr 1fr;        /* fixed + flexible */
    grid-template-columns: repeat(3, 1fr);        /* 3 equal columns */
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr)); /* responsive */

    /* Define rows */
    grid-template-rows: auto 1fr auto;            /* header, content, footer */

    /* Gaps */
    gap: 1rem;            /* both row and column gap */
    row-gap: 0.5rem;
    column-gap: 1.5rem;

    /* Alignment */
    justify-items: stretch;   /* horizontal alignment of cells */
    align-items: start;       /* vertical alignment of cells */
    justify-content: center;  /* horizontal alignment of the grid */
    align-content: center;    /* vertical alignment of the grid */
}

/* Place items */
.item {
    grid-column: 1 / 3;      /* span from column 1 to 3 */
    grid-row: 1 / 2;
    grid-column: span 2;      /* span 2 columns */
    grid-area: 1 / 1 / 3 / 3; /* row-start / col-start / row-end / col-end */
}

grid-template-areas : définition visuelle de la mise en page

grid-template-areas permet de définir la mise en page visuellement en ASCII.

/* grid-template-areas: name regions visually */
.page-layout {
    display: grid;
    grid-template-areas:
        "header  header  header"
        "sidebar main    main"
        "sidebar aside   aside"
        "footer  footer  footer";
    grid-template-columns: 250px 1fr 300px;
    grid-template-rows: 60px 1fr auto 80px;
    min-height: 100vh;
    gap: 1rem;
}

.header  { grid-area: header; }
.sidebar { grid-area: sidebar; }
.main    { grid-area: main; }
.aside   { grid-area: aside; }
.footer  { grid-area: footer; }

/* Responsive: stack on mobile */
@media (max-width: 768px) {
    .page-layout {
        grid-template-areas:
            "header"
            "main"
            "aside"
            "sidebar"
            "footer";
        grid-template-columns: 1fr;
        grid-template-rows: auto;
    }
}

auto-fill vs auto-fit : responsive sans media queries

auto-fill et auto-fit avec minmax() créent des grilles responsive sans media queries.

/* auto-fill vs auto-fit — the most important Grid distinction */

/* auto-fill: creates as many columns as possible, even if empty */
.gallery-fill {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 1rem;
}
/* Result: always fills the row with tracks, even with empty ones */

/* auto-fit: collapses empty tracks, stretches filled items */
.gallery-fit {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 1rem;
}
/* Result: items expand to fill available space */

/* Practical: responsive card grid (no media queries!) */
.card-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(min(300px, 100%), 1fr));
    gap: 1.5rem;
}
/* min(300px, 100%) prevents overflow on very small screens */

minmax() et dimensionnement intrinsèque

minmax(min, max) définit les tailles minimale et maximale d'une piste de grille.

/* minmax() — set minimum and maximum track size */

/* Card layout: minimum 250px, maximum 1fr */
.cards {
    display: grid;
    grid-template-columns: repeat(3, minmax(250px, 1fr));
}

/* Intrinsic sizing with min-content / max-content */
.table-grid {
    display: grid;
    grid-template-columns: max-content 1fr max-content;
    /* First and last columns size to content, middle fills rest */
}

/* fit-content() — like minmax(auto, max-content) but capped */
.nav {
    display: grid;
    grid-template-columns: fit-content(200px) 1fr fit-content(200px);
}

/* Dense packing: fill holes left by spanning items */
.masonry-like {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(150px, 1fr));
    grid-auto-rows: 150px;
    grid-auto-flow: dense; /* fills gaps automatically */
}

.tall-item {
    grid-row: span 2; /* takes 2 rows */
}
.wide-item {
    grid-column: span 2; /* takes 2 columns */
}

Subgrid : CSS Grid Level 2 (2026)

Subgrid permet à une grille imbriquée de participer à la définition des pistes de la grille parente.

/* Subgrid — CSS Grid Level 2, fully supported in 2026 */
/* Allows nested grids to align to parent grid lines */

/* The problem subgrid solves: */
.card-container {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 1rem;
}

/* Without subgrid: each card's internal layout is independent */
/* Card titles and content don't align across cards */

/* With subgrid: */
.card {
    display: grid;
    grid-row: span 3; /* card spans 3 implicit rows */
    grid-template-rows: subgrid; /* inherits parent row tracks */
}
/* Now all cards share the same row grid — titles align! */

.card .card-header { grid-row: 1; }
.card .card-body   { grid-row: 2; }
.card .card-footer { grid-row: 3; }

/* Subgrid for columns too */
.sidebar-layout {
    display: grid;
    grid-template-columns: 1fr 3fr;
}

.main-content {
    display: grid;
    grid-column: 2;
    grid-template-columns: subgrid; /* aligns to parent columns */
}

/* Browser support: Chrome 117+, Firefox 71+, Safari 16+ — all major browsers */

Animations et transitions Grid

Les navigateurs modernes supportent la transition de grid-template-columns et grid-template-rows.

/* Grid transitions and animation */

/* Animate grid column width on hover */
.sidebar-layout {
    display: grid;
    grid-template-columns: 250px 1fr;
    transition: grid-template-columns 0.3s ease;
}

.sidebar-layout:has(.sidebar:hover) {
    grid-template-columns: 350px 1fr; /* expand on hover */
}

/* CSS-only accordion with Grid */
.accordion-item {
    display: grid;
    grid-template-rows: auto 0fr; /* collapsed: 0 fraction */
    transition: grid-template-rows 0.3s ease;
    overflow: hidden;
}

.accordion-item.open {
    grid-template-rows: auto 1fr; /* expanded: 1 fraction */
}

.accordion-content {
    min-height: 0; /* required for 0fr to work */
}

CSS Grid vs Flexbox : quand utiliser quoi

Bonnes pratiques

• Grid pour les mises en page globales, Flexbox pour les composants.
• Préférer repeat(auto-fill, minmax()) pour les grilles de cartes responsive.
• Nommer les zones avec grid-template-areas pour les mises en page complexes.
• Utiliser subgrid pour aligner les contenus dans des éléments grid séparés.
• Utiliser gap au lieu de margins pour l'espacement.

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